JP3215400B1 - Image display device and image display method - Google Patents

Image display device and image display method

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Publication number
JP3215400B1
JP3215400B1 JP2001139306A JP2001139306A JP3215400B1 JP 3215400 B1 JP3215400 B1 JP 3215400B1 JP 2001139306 A JP2001139306 A JP 2001139306A JP 2001139306 A JP2001139306 A JP 2001139306A JP 3215400 B1 JP3215400 B1 JP 3215400B1
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Japan
Prior art keywords
video signal
signal
image display
unit
light source
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JP2001139306A
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Japanese (ja)
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JP2002041007A (en
Inventor
義人 太田
隆宏 小林
克行 有元
太朗 船本
Original Assignee
松下電器産業株式会社
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Priority to JP11-128602 priority
Application filed by 松下電器産業株式会社 filed Critical 松下電器産業株式会社
Priority to JP2001139306A priority patent/JP3215400B1/en
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Publication of JP3215400B1 publication Critical patent/JP3215400B1/en
Publication of JP2002041007A publication Critical patent/JP2002041007A/en
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Classifications

    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611Control of matrices with row and column drivers
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406Control of illumination source
    • GPHYSICS
    • G09EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09GARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00Control of display operating conditions
    • G09G2320/06Adjustment of display parameters
    • G09G2320/0626Adjustment of display parameters for control of overall brightness
    • G09G2320/0653Controlling or limiting the speed of brightness adjustment of the illumination source

Abstract

Provided is an image display device and a method for improving a sense of visual contrast by adjusting contrast and a light source with a correlation therebetween. SOLUTION: A characteristic detecting unit 11 is configured to output an MA of an input video signal.
X, MIN, and APL are detected. Control data generator 12
Is an Gain that amplifies the difference between MAX and MIN up to the dynamic range width, and an Offset that provides a DC level shift amount that allows the input video signal amplified by the Gain to be within the output dynamic range of the DC level adjustment unit 13B.
And ask. The signal amplitude adjuster 13A amplifies the input video signal in accordance with the gain based on the APL. The DC level adjustment unit 13B outputs the amplified input video signal to Off
The level is shifted according to the value of set. Light source controller 16
Controls the light source 18 based on the Offset so that the visual luminance level on the screen is equal to the luminance level of the input video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image display device and an image display method, and more particularly, to a light-receiving type light modulation device which dynamically adjusts contrast and brightness of a light source according to an input video signal. The present invention relates to an image display device and a method using an element.

[0002]

2. Description of the Related Art As is well known, many image display devices are used as screen display devices such as television receivers and computer devices. Among them, a light receiving type device represented by a liquid crystal display device displays an image on a non-light emitting type light receiving type light modulator (for example, a liquid crystal panel). The screen is darker than that of. For this reason, a light receiving type image display device is usually provided with a light source (for example, a backlight) for irradiating light from the back of the light receiving type light modulator to increase the visual brightness of the display screen, and generally adjusting contrast. In addition to this, the brightness of the light source can be adjusted so that the displayed image can be easily viewed.

[0003] Basically, the contrast and the level of the light source are fixedly set to contents that are manually adjusted by the user. However, in recent years, various methods have been proposed for dynamically adjusting the contrast and the light source in accordance with an input video signal that changes as needed in order to make the image easier to see.

The contrast and the light source (backlight)
As a conventional method for dynamically adjusting the brightness, there is, for example, a method disclosed in Japanese Patent Application Laid-Open No. 5-127608 "Liquid crystal display device". In the conventional adjustment method disclosed in this publication, the maximum luminance level (MA
X) and the minimum luminance level (MIN) are detected. If the difference between the maximum luminance level and the minimum luminance level is large, the contrast is lowered. If the difference between the maximum luminance level and the minimum luminance level is small, the contrast is reduced. increase. Also, by detecting the average luminance level (APL) of the input video signal, the luminance of the backlight is decreased when the average luminance level is higher than a predetermined reference luminance level, and the luminance of the backlight is increased when the average luminance level is lower than the predetermined reference luminance level. This is to obtain a constant display luminance.

[0005]

However, in the conventional adjusting method disclosed in the above publication, the adjustment of the contrast (that is, the signal amplitude control) and the brightness adjustment of the light source (backlight) are independently performed. (That is, there is no correlation between the two adjustments), it is not possible to obtain a sufficient effect of improving the contrast feeling.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to adjust the contrast (signal amplitude control) and the brightness adjustment of the light source so as to provide a visual contrast without increasing the power consumption of the light source. It is an object of the present invention to provide an image display device and an image display method capable of improving a feeling.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an image display apparatus for displaying an input video signal on a light receiving type light modulating means having a light source.
A contrast adjusting means for dynamically performing predetermined contrast adjustment, and a visual average luminance level when an image is displayed on the light receiving type light modulating means based on a DC level which varies with the contrast adjustment performed by the contrast adjusting means. And a light source luminance adjusting means for adjusting the luminance of the light source so that the light intensity does not change.

As described above, according to the present invention, the brightness of the light source is adjusted so that the average brightness level does not change by giving a correlation with the contrast adjustment performed by the contrast adjusting means. This makes it possible to improve the sense of visual contrast without increasing the average power consumption of the light source.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram showing a configuration of an image display device according to a first embodiment of the present invention. 1, the image display device according to the first embodiment includes a feature detection unit 11, a control data generation unit 12, an input signal processing unit 13, a light source control unit 16, and a light receiving type light modulation unit 17. Prepare. Also, the input signal processing unit 1
3 is a signal amplitude adjuster 13A and a DC level adjuster 13
B. The light receiving type light modulator 17 includes a light source 18.

Hereinafter, the operation (image display method) of each component of the image display device according to the first embodiment of the present invention will be described with further reference to FIGS. FIG. 2 and FIG.
FIG. 3 is a diagram illustrating an example of a schematic process performed by the image display device according to the first embodiment of the present invention on a certain input video signal.

First, a video signal output from a video signal processing circuit (not shown) such as a television receiver or a computer device is used as an input video signal as a signal amplitude adjuster of the feature detector 11 and the input signal processor 13. 13A. The feature detection unit 11 outputs a maximum luminance level (hereinafter, referred to as MAX), a minimum luminance level (hereinafter, referred to as MIN), and an average luminance level (hereinafter, referred to as AP) of the input video signal.
L) are respectively detected. Note that the detection of MAX, MIN, and APL performed by the feature detection unit 11 is a conventionally performed process, and thus a detailed description thereof will be omitted.

The control data generation unit 12 includes a feature detection unit 11
Input the detected MAX, MIN, and APL, and adjust the signal amplitude adjustment gain (hereinafter, referred to as “ gain”) and the DC level shift amount of the video signal (hereinafter, “Offset” ).
Fset) is obtained as follows. Now, the feature detecting unit 11 applies the MAX, MIN and APL as shown in FIG. 2A or FIG.
Is detected.

First, the control data generation unit 12 determines the maximum amplitude (difference between MAX and MIN) of the input video signal by a signal processing range of the processing circuit, that is, a dynamic range (specifically, a DC level adjustment unit). Gain for amplifying up to 13B output dynamic range) width is obtained according to the following equation. Gain = dynamic range / (MAX-MIN) For example, in FIG. 2, the case where the maximum amplitude of the input video signal is 67% of the dynamic range width (FIG. 2)
(A)) Gain obtained by the control data generation unit 12 is
It becomes about 1.5 times (FIG. 2B). This calculated Ga
in is output to the signal amplitude adjustment unit 13A.

Next, the control data generating section 12 outputs the input video signal (hereinafter, referred to as the input video signal) amplified by the signal amplitude adjusting section 13A.
Offset that gives a DC level shift amount within which the amplified video signal falls within the dynamic range is obtained.
This corresponds to the signal amplitude adjustment unit 13A performing amplification on the basis of the APL (fixing the DC level of the APL). The DC level of the amplified video signal is adjusted so that the amplitude of the amplified video signal falls within the dynamic range. It changes. For example, in FIG. 2, when the amplitude of the amplified video signal exceeds the lower limit of the dynamic range by 0.5 V, the Offset obtained by the control data generator 12 is 0.5 V
(FIG. 2C). This determined Offset
Is output to the DC level adjustment unit 13B and the light source control unit 16.

The signal amplitude adjustment unit 13A includes an input video signal, an APL output from the feature detection unit 11, and a control data generation unit 1.
2 is input. Then, the signal amplitude adjustment unit 13A amplifies the input video signal in accordance with the gain with reference to the APL (FIGS. 2B and 3).
(B)). This amplified video signal is supplied to the DC level adjuster 13
B. Since the output dynamic range of the signal amplitude adjustment unit 13A has a sufficient width compared with the output dynamic range of the DC level adjustment unit 13B, for example, a signal portion exceeding the lower limit of the dynamic range in FIG. Given as a negative signal.

The DC level adjuster 13B includes an amplified video signal output from the signal amplitude adjuster 13A and the control data generator 1
2 is input. And DC
The level adjustment unit 13B adjusts the DC level of the amplified video signal,
The level is shifted by the value of Offset (see FIG. 2).
(C), FIG. 3 (c)). The amplified video signal after the level shift (hereinafter referred to as an output video signal) is output to the light receiving type light modulation unit 17 and displayed as an image.

The light source controller 16 controls the control data generator 12
In accordance with the Offset output from the input video signal, that is, the visual luminance level in the output video signal is equal to the luminance level of the input video signal, that is, the APL when displaying an image on the light receiving type light modulation unit 17 is the APL in the input video signal. Then, a predetermined luminance adjustment is performed on the light source 18 so as to be the same as in (2) and (d) of FIG. As described above, by absorbing the fluctuation of the APL generated by the DC level adjustment unit 13B, the luminance of the light source 18 is reduced, and the visual luminance level is further reduced with respect to the black level. Is up (Fig. 2
(D)). Further, as for the white level, the visual white peak becomes higher as the luminance of the light source 18 increases, and as a result, the bright part becomes more prominent and the contrast feeling is improved (FIG. 3D). ).

As described above, according to the image display apparatus and method according to the first embodiment of the present invention, the input signal processing unit 13 (the signal amplitude adjustment unit 13A and the DC level adjustment unit 1)
The light source 1 has a correlation with the signal amplitude control performed in 3B).
8 to adjust the APL variation of the output video signal with respect to the input video signal. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18.

In the first embodiment, a case has been described in which a gain for amplifying up to a dynamic range width is set as the gain required by the control data generation unit 12. It is also possible to set the gain to be less than or equal to the dynamic width that is most effective visually according to the noise state and the state of the color gain.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
FIG. 3 is a block diagram illustrating a configuration of an image display device according to the embodiment. 4, the image display device according to the second embodiment includes a feature detection unit 11, a control data generation unit 12,
An input signal processing unit 13, a light source control unit 16, and a light receiving type light modulation unit 17 are provided. In addition, the input signal processing unit 13
It has a C level adjustment unit 13B and a signal amplitude adjustment unit 13A. The light receiving type light modulator 17 includes a light source 18.

As shown in FIG. 4, the image display device according to the second embodiment includes a signal amplitude adjustment unit 13A in the input signal processing unit 13 of the image display device according to the first embodiment.
This is a configuration in which the processing order between the DC level adjustment unit 13B and the DC level adjustment unit 13B is changed. The components of the image display device according to the second embodiment are the same as the components of the image display device according to the first embodiment, and the same components are denoted by the same reference numerals and will be described. Omitted. Hereinafter, an image display device according to the second embodiment of the present invention will be described focusing on processing operations different from those of the image display device according to the first embodiment.

The DC level adjuster 13B receives the input video signal and the Offset output from the control data generator 12. Then, the DC level adjusting unit 13B shifts the DC level of the input video signal by the value of Offset. The signal amplitude adjustment unit 13A includes an input video signal after the level shift processing output from the DC level adjustment unit 13B, an APL output from the feature detection unit 11, and the control data generation unit 1
2 is input. Then, the signal amplitude adjustment unit 13A amplifies the input video signal after the level shift processing in accordance with the gain based on the APL. The input video signal (output video signal) after the amplification is output to the light receiving type light modulator 17 and displayed as an image.

Therefore, as in the first embodiment, D
By absorbing the variation of the APL generated by the C level adjusting unit 13B, the brightness of the light source 18 is reduced, and the visual brightness level is further reduced with respect to the black level. FIG.
(D)). As for the white level, the light source 18
As the luminance increases, the visual white peak becomes higher, and consequently the bright portion becomes more prominent, and the sense of contrast is improved (see FIG. 3D).

As described above, according to the image display apparatus and method according to the second embodiment of the present invention, the input signal processing unit 13 (the signal amplitude adjustment unit 13A and the DC level adjustment unit 1)
The light source 1 has a correlation with the signal amplitude control performed in 3B).
8 to adjust the APL variation of the output video signal with respect to the input video signal. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18.

In the second embodiment, a case has been described in which a gain for amplifying up to the dynamic range width is set as the Gain determined by the control data generation unit 12. However, other than this, the input video signal It is also possible to set the gain to be less than or equal to the dynamic width that is most effective visually according to the noise state and the state of the color gain.

(Third Embodiment) When the process of extending the signal amplitude or the process of increasing the light source luminance as described in the first and second embodiments is performed, the noise component of the input video signal also increases. And the image quality is degraded. Therefore, the third embodiment of the present invention is designed to reduce the noise component when the above processing is performed.

FIG. 5 is a block diagram showing a configuration of an image display device according to a third embodiment of the present invention. 5, the image display device according to the third embodiment includes a feature detection unit 11, a control data generation unit 12, a noise control data generation unit 31, a noise reduction unit 32, and an input signal processing unit 13
, A light source controller 16 and a light receiving type light modulator 17. The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 5, the image display device according to the third embodiment further includes a noise control data generation unit 31 and a noise reduction unit 32 in the image display devices according to the first and second embodiments. This is an added configuration. Other configurations of the image display device according to the third embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Hereinafter, an image display device according to the third embodiment of the present invention will be described focusing on components different from those of the image display devices according to the first and second embodiments.

The noise control data generator 31 receives the Gain and Offset output from the control data generator 12. Then, the noise control data generation unit 31
The noise amount increasing by the signal processing is determined according to the values of “ain” and “Offset”, and a predetermined noise reduction signal corresponding to the noise amount is generated.
Output to 2.

The noise reduction unit 32 receives the input video signal and the noise reduction signal output from the noise control data generation unit 31, and reduces a noise component from the input video signal according to the noise reduction signal. As a configuration of the noise reduction unit 32, for example, a noise filter, a contour correction circuit, or the like can be considered. When the noise reduction unit 32 is configured by a noise filter, a method of controlling the level of filtering in accordance with the noise reduction signal can be considered (specifically, the threshold value for filtering is increased in proportion to the increase in the amount of noise). Do). When the noise reduction unit 32 is configured by a contour correction circuit, a method of controlling the level of contour correction or the level of coring according to the noise reduction signal can be considered (specifically, in proportion to an increase in the amount of noise). Reduce the level of contour correction or increase the level of coring). Then, the input video signal subjected to the noise reduction is output to the input signal processing unit 13, and thereafter, the same processing as in the first or second embodiment is performed.

As described above, according to the image display apparatus and method according to the third embodiment of the present invention, the luminance of the light source is adjusted so as to have a correlation with the signal amplitude control, and the output image with respect to the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the noise component to be expanded is reduced according to the signal amplitude control and the light source luminance adjustment performed. This makes it possible to improve the sense of visual contrast without increasing the noise component and without increasing the average power consumption of the light source 18.

In the noise control data generating section 31 of the third embodiment, it is also possible to suppress the color gain from being excessively increased according to the value of the gain and the DC level difference. Gain and D
In addition to the C level, it is also possible to determine the amount of noise that increases due to signal processing in consideration of the γ characteristics of the liquid crystal.

(Fourth Embodiment) A light source as described in the first and second embodiments is applied to an input video signal in which a bright image includes a small area near black in a bright image. When the processing for increasing the luminance is performed, the black level is floated. Therefore, in the fourth embodiment of the present invention, the floating of the black level when the luminance of the light source is high is reduced, and the sense of contrast is improved.

FIG. 6 is a block diagram showing a configuration of an image display device according to a fourth embodiment of the present invention. 6, the image display device according to the fourth embodiment includes a feature detection unit 11, a data determination unit 41, and a control data generation unit 42.
, An input signal processing unit 13, a light source control unit 16, and a light receiving type light modulation unit 17. Also, the light receiving type light modulating unit 17
Includes a light source 18.

As shown in FIG. 6, in the image display device according to the fourth embodiment, the control data generator 12 of the image display device according to the first and second embodiments is replaced with a control data generator 42. , And a data determination unit 41. Other configurations of the image display device according to the fourth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Hereinafter, an image display device according to a fourth embodiment of the present invention will be described with further reference to FIG. 7, focusing on components different from those of the image display devices according to the first and second embodiments. FIG. 7 is a diagram illustrating an example of an outline of a process performed by an image display device according to a fourth embodiment of the present invention on a certain input video signal.

The data judging section 41 receives an input video signal and calculates the number of pixels (hereinafter referred to as CNT) of the input video signal having a luminance level equal to or lower than a predetermined luminance level. This luminance level is a reference level for determining how much the pixel on the black level side is included in the entire screen, and can be arbitrarily determined according to the image quality to be obtained. Therefore, CNT is the number of pixels on the black level (low luminance level) side determined according to the luminance level. The unit of the CNT can be arbitrarily determined according to the processing purpose, and may be, for example, a unit of one pixel or a unit of a rectangular area including a plurality of pixels. Note that the data determination unit 41
In, if the number of pixels is detected for each signal level over the entire signal level, the accuracy of the processing can be improved.

The control data generation unit 42 includes the feature detection unit 11
Input the MAX, MIN, and APL detected by, and the CNT output from the data determination unit 41, and input Gain and Offs.
is determined as follows.

First, similarly to the control data generator 12, the control data generator 42 receives the input video signal (FIG. 7).
A gain for amplifying the maximum amplitude of (a)) up to the dynamic range width is obtained and output to the signal amplitude adjustment unit 13A of the input signal processing unit 13. Next, the control data generator 4
2, the amplified video signal (FIG. 7B) output from the signal amplitude adjustment unit 13A is similar to the control data generation unit 12.
An Offset that gives a DC level shift amount that falls within the dynamic range is obtained.

Next, the control data generator 42 determines whether or not the input video signal has few signals on the black level side and low gradation based on the APL and the CNT. That is, when the APL is higher than the predetermined reference level and the CNT is lower than the predetermined reference number, the control data generation unit 42 determines that the input video signal has few signals on the black level side and low gradation. Judge. The reference level and the reference number can be arbitrarily determined according to the image quality to be obtained.

When the control data generation section 42 determines that the input video signal is a signal having a low black level and a low gradation, the predetermined video signal in the amplified video signal is determined. Is reduced by the dynamic range (FIG. 7 (c)). The amount by which the value of Offset is reduced can be arbitrarily determined according to the image quality to be obtained. Then, the control data generation unit 42 outputs the reduced Offset to the DC level adjustment unit 13B and the light source control unit 16 of the input signal processing unit 13. As a result, it is possible to crush low-luminance portions having few gradations and tighten the black level side. In addition, since the APL is reduced by crushing the low luminance portion, the white peak level visually increases when the light source luminance is adjusted (FIG. 7D).

If the control data generation unit 42 does not judge that the input video signal is a signal with a low black level and a low gradation, the control data generation unit 42 adjusts the already obtained Offset without changing the DC level. It outputs to the unit 13B and the light source control unit 16. Thereafter, the same processing as in the first or second embodiment is performed.

As described above, according to the image display apparatus and method according to the fourth embodiment of the present invention, the luminance of the light source is adjusted while having a correlation with the signal amplitude control, and the output image for the input image signal is adjusted. In absorbing the APL fluctuation of the signal, a process of crushing the gradation of the low luminance portion is performed on the input video signal in which the black level floats. This makes it possible to tighten the black level and increase the white peak level even for an input video signal that includes a black area image with a small area in a bright image as a whole, thereby improving the sense of visual contrast. be able to.

In the fourth embodiment, the configurations of the data determination unit 41 and the control data generation unit 42 are
The case where the configuration is used in the image display devices according to the first and second embodiments has been described. However, the same effect can be obtained by using the configuration in the image display device according to the third embodiment. is there. Further, in the fourth embodiment,
If it is determined that the signal on the black level side is small,
The process of crushing the dynamic range on the black side by lowering the value of set is performed. However, besides this process, for example, the γ characteristic on the black side is moderate and the γ characteristic on the white side is sharpened. The same effect can be obtained by performing the processing of crushing the black side and expanding the white side. Further, as described in the fourth embodiment, when the gain calculated as a standard is used, the black side is crushed, so that the white side has a margin for the dynamic range. Therefore, in order to eliminate the margin and use the dynamic range more effectively, it is possible to calculate a large gain in consideration of the black level crush and use this gain for control.

(Fifth Embodiment) On the other hand, the above-mentioned first and second input video signals can be applied to an input video signal in which a portion of the light source 18 that is effective in brightening the light source is small (for example, a black image is dominant in most portions). Even when the process of increasing the light source luminance as described in the embodiment is performed, the black level is floated.
Therefore, in the fifth embodiment of the present invention, the change in the light source luminance is suppressed for the input video signal as described above, the floating of the black level is reduced, and the sense of contrast is improved.

FIG. 8 is a block diagram showing a configuration of an image display device according to a fifth embodiment of the present invention. 8, the image display device according to the fifth embodiment includes a feature detection unit 11, a data determination unit 51, and a control data generation unit 52.
, An input signal processing unit 13, a light source control unit 16, and a light receiving type light modulation unit 17. Also, the light receiving type light modulating unit 17
Includes a light source 18.

As shown in FIG. 8, in the image display device according to the fifth embodiment, the control data generation unit 12 of the image display device according to the first and second embodiments is replaced with a control data generation unit 52. , And a data determination unit 51 is further added. The other configurations of the image display device according to the fifth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Hereinafter, an image display device according to the fifth embodiment of the present invention will be described focusing on components different from those of the image display devices according to the first and second embodiments.

The data judging section 51 receives the input video signal, extracts a bright area from the input video signal, judges whether the bright area is larger or smaller than a predetermined value, and sends it to the control data generating section 52. Output. Here, as a method of extracting and determining a bright area performed by the data determination unit 51, for example, first, the MAX of the input video signal is detected,
A method for extracting a region indicating X and a predetermined MAX approximation value and determining whether the region is equal to or larger than a predetermined area, or a method for determining whether the number of pixels included in the region is equal to or larger than a predetermined number. A method of determining whether or not there is, or the like can be considered.

The control data generation unit 52 includes the feature detection unit 11
The MAX, MIN, and APL detected by the controller and the determination result output from the data determination unit 51 are input, and Gain and Off are input.
set is obtained as follows.

First, similarly to the control data generator 12, the control data generator 52 obtains a Gain for amplifying the maximum amplitude of the input video signal to the dynamic range width, and adjusts the signal amplitude of the input signal processor 13. Output to the unit 13A. Next, similarly to the control data generation unit 12, the control data generation unit 52 obtains an Offset that gives a DC level shift amount within which the amplified video signal output from the signal amplitude adjustment unit 13A falls within the dynamic range. And
The control data generator 52 changes the calculated Offset based on the determination result. Here, the control data generator 5
No. 2 changes the DC level difference so that the brightness level of the light source 18 decreases when the bright area is smaller than a predetermined value. Then, the Offset changed based on the determination result is output to the DC level adjustment unit 13B and the light source control unit 16, and thereafter, the same processing as in the first or second embodiment is performed.

As described above, according to the image display apparatus and method according to the fifth embodiment of the present invention, the brightness of the light source is adjusted with a correlation with the signal amplitude control, and the output for the input video signal is adjusted. In absorbing the APL fluctuation of the video signal, a process of lowering the luminance of the light source 18 is performed on an input video signal in which the black level is conspicuous because there are few bright areas. As a result, the black level can be reduced even for an input video signal having a small number of bright regions, and the sense of visual contrast can be improved.

In the fifth embodiment, the configuration of the data determination unit 51 and the control data generation unit 52 is
The case where the present invention is applied to the image display devices according to the first and second embodiments has been described.
The same effect can be obtained even when used in the image display device according to the embodiment. In the fifth embodiment, it is determined whether the bright area of the input video signal is larger or smaller than a predetermined value, and the ON / OFF control of the light source 18 is performed based on the result of the determination. It is also possible to obtain byte information indicating the size of the bright area and to linearly control the light source 18 based on the byte information.

(Sixth Embodiment) By the way, there are various display modes such as letter box and side black in the input video signal. In some cases, character information such as an OSD signal (on-screen display signal) is superimposed on an input video signal. Therefore, if such contrast adjustment and light source luminance adjustment as described in the first to fifth embodiments are simply performed on such an input video signal, an appropriate image display may not be obtained. appear. Therefore, the sixth embodiment of the present invention provides appropriate contrast adjustment and control for input video signals in various display modes and for input video signals on which character information such as an OSD signal is superimposed. Light source luminance adjustment is performed.

FIG. 9 is a block diagram showing a configuration of an image display device according to the sixth embodiment of the present invention. In FIG. 9, the image display device according to the sixth embodiment includes a feature detection unit 61, a control data generation unit 12, and an input signal processing unit 13.
, A light source controller 16 and a light receiving type light modulator 17. The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 9, the image display device according to the sixth embodiment has a configuration in which the feature detection unit 61 of the image display devices according to the first and second embodiments is replaced with a feature detection unit 61. It is. The other configurations of the image display device according to the sixth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Hereinafter, the image display device according to the sixth embodiment of the present invention will be described with reference to the first embodiment.
The following description focuses on components different from those of the image display device according to the second embodiment.

The feature detector 61 receives an input video signal, and first determines the display mode of the input video signal and the presence or absence of an OSD signal. The display mode and the presence / absence of the OSD signal may be determined by the feature detection unit 61 by analyzing the input video signal by itself, or may be given from outside. Next, based on the determined display mode, the feature detection unit 61 determines the areas for detecting MAX, MIN, and APL, respectively. For example, the detection area is an area excluding the upper and lower portions of the screen when the display mode is letterbox, and is an area excluding the left and right portions of the screen when the display mode is side black. Alternatively, when the display mode is letterbox, the detection may be weighted between the upper and lower portions of the screen and the other main portions to perform detection on the entire screen. The detection may be weighted for the portion and the other main portion, and the detection may be performed on the entire screen.

On the other hand, when it is determined that there is an OSD signal,
The feature detecting unit 61 excludes a part of the OSD display area (predetermined by the apparatus) from the detection area. Then, the feature detecting unit 61 sets MAX, M in the determined detection area.
IN and APL are respectively detected and output to the control data generation unit 12, the input signal processing unit 13, and the light source control unit 16.

As described above, according to the image display apparatus and the method according to the sixth embodiment of the present invention, the light source luminance is adjusted with a correlation with the signal amplitude control, and the output image with respect to the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the display mode and the OSD display of the input video signal are determined to determine an appropriate detection area. This makes it possible to appropriately improve the sense of visual contrast without being affected by an area that constantly displays a black level such as a letter box or side black or an OSD display area having a high white peak. .

In the sixth embodiment, the case where the configuration of the feature detection unit 61 is used in the image display devices according to the first and second embodiments has been described. The same effects can be obtained even when used in the image display devices according to the third to fifth embodiments. Although the feature detection unit 61 in the sixth embodiment has been described to perform both the determination of the display mode and the determination of the presence / absence of the OSD signal, only one of them may be performed. Furthermore, in the sixth embodiment, the case where the character information is an OSD signal has been described as an example, but all other character information that hinders improvement in visual contrast is described above. It goes without saying that if the processing is applied, useful effects of the present invention can be obtained.

(Seventh Embodiment) There are various types and modes of input video signals. Therefore, if such contrast adjustment and light source luminance adjustment as described in the first to fifth embodiments are simply performed on such an input video signal, an appropriate image display may not be obtained. appear. Therefore, in the seventh embodiment of the present invention, appropriate contrast adjustment and light source luminance adjustment are performed for input video signals of various types and modes.

FIG. 10 is a block diagram showing the configuration of an image display device according to the seventh embodiment of the present invention. In FIG. 10, the image display device according to the seventh embodiment includes a feature detection unit 11, a control data generation unit 72, an input signal processing unit 13, a light source control unit 16, and a light receiving type light modulation unit 17. Prepare. The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 10, in the image display device according to the seventh embodiment, the control data generator 12 of the image display device according to the first and second embodiments is replaced with a control data generator 72. Configuration. Other configurations of the image display device according to the seventh embodiment are the same as the configurations of the image display devices according to the first and second embodiments.
The same reference numerals are given to the same components, and the description is omitted. Hereinafter, after classifying the image display device according to the seventh embodiment of the present invention into types and modes of input video signals,
The following description focuses on components that are different from the image display devices according to the first and second embodiments.

(1) In the case of a blue-back signal or a signal at the time of mode transition This is because the entire input video signal is a blue-back signal of a blue color or an entire surface used for mode transition such as scene switching (for example, fade in / fade out) This is a case of a special signal such as a white signal. In the case of such a special signal, there is no need to improve the image quality, and it is preferable to basically display an input signal as it is without performing contrast adjustment and light source luminance adjustment. Therefore, the control data generation unit 7
In 2, the following processing is performed.

The control data generation unit 72 includes the feature detection unit 11
Inputs MAX, MIN and APL detected by
The level difference between X and MIN is a predetermined value (hereinafter, TH_
LVL) is determined.
This is because a signal such as the blue-back signal described above is M
This is based on the fact that there is not much level difference between AX and MIN. When the control data generation unit 72 determines that the level difference is larger than TH_LVL,
Alternatively, as described in the second embodiment, Gain and Offset corresponding to the input video signal are obtained and output. On the other hand, the control data generation unit 72 determines that the level difference is TH_
If it is determined that the input video signal is smaller than the LVL, it is determined that the input video signal is a special signal such as a blue-back signal, and a value whose control effect is weakened is output to the calculated Gain and Offset. Specifically, Gain and Offset for which adjustment is not performed are respectively referred to as Gain_
Type and Offset_Type, and output Ga
in and Offset are respectively Gain_Out
And Offset_Out, the following equation: Gain # Out = Gain # Typ + (Gain-Gain # Typ) * ((MAX-MIN) / TH # L
VL) Offset # Out = Offset # Typ + (Offset-Offset # Typ) * ((MAX-M
IN) / TH # LVL) to calculate Gain_Out and Offset_Out.

By this processing, it is possible to prevent overcorrection due to unnecessary control and reduce power consumption. The predetermined value can be set arbitrarily according to the level of the special signal to be input. In the above description, the processing performed by the control data generation unit 72 is MAX MAX
A method has been described in which when the level difference between MIN and MIN is smaller than a predetermined value, the signal is determined to be a special signal and the gain is gradually made closer to 1 according to (MAX-MIN). It is also possible to use a method of making a determination based on color, synchronization (for example, not being an interlaced signal), or the like.

(2) In the case of a signal having a change only in a minute area This is because the input video signal has a change in a part of the entire screen, that is, a large part of the image has no significant change and This is a case where the signal has a change only in a part of the region. In the case of such a signal, if the contrast adjustment and the light source luminance adjustment are performed under the influence of the changing area, a sense of incongruity may be visually provided in an area that does not greatly change and occupies most of the image. For this reason,
In the case of such a signal, it is preferable that the adjustment value is not largely changed from the adjustment value processed last time, that is, the change between the previous output image and the current output image is preferably reduced. Therefore, the following processing is performed in the control data generation unit 72.

As a premise, the control data generation unit 72 determines the previously processed MAX, MIN, APL, Gain and O
ffset is held. The control data generation unit 72 inputs MAX, MIN, and APL detected by the feature detection unit 11, and compares the MAX, MIN, and APL with the previous APL holding the newly input APL to determine a difference between the changes. This is based on the fact that the signal having a change only in the above-described minute area has almost no change in the APL. Then, when there is no difference in the change, the control data generation unit 72 calculates the Gain and Offset processed last time,
If there is a difference in the change, the MA and the current offset and the current MA
Gain calculated based on X, MIN and APL
Gain and Offset up to and Offset
With Gain and Offse corresponding to the input video signal.
It is variably output as t. This is, for example, Gain
And low-pass through the Offset
A filter (LPF) is provided, and when the difference between the changes is small, the time constant of the LPF is large (the amount of change is small), and when the difference between the changes is large, the time constant of the LPF is small (the amount of change is large). What should I do? When the difference between the changes is large, the current MAX, MIN and A
Gain and Offset calculated based on PL
May be controlled to converge to
Control may be performed so as to converge to ain and Offset.

By this processing, although the effect of improving the image quality of the image alone is slightly reduced, visual discomfort due to unnecessary control can be suppressed, and the connection before and after the image can be expressed naturally. It should be noted that the variable amount according to the difference between the changes can be arbitrarily set in accordance with the level of the input signal. Further, in the control data generation unit 72, whether or not a signal has a change only in a minute area is determined only by a change in APL, but it is also possible to determine by using a change in MAX or MIN. Further, the control data generation unit 72 can improve the accuracy of the determination by detecting the histogram data indicating that most of the image does not change.

(3) In the case of a signal having a large change This is a case where the input video signal is a signal having a large change due to a scene change or the like. Here, even if there is no change in the image, since the input video signal slightly changes on the time axis (due to noise or the like), the adjustment level is changed each time for this minute change. The image flickers and makes it hard to see. Therefore, in general, a low-pass filter (LPF) is provided in the control data generator 72 to adjust (adjust) the contrast and the light source luminance after absorbing (smoothing) a minute change, so that the image can be viewed. The ease is secured. However, even in the case of the above-mentioned signal having a large change, if each adjustment is performed after smoothing through the LPF, it is not possible to realize the adjustment faithfully corresponding to the signal. Therefore, for a signal having a large change, LP
It is preferable to perform each adjustment without passing through F. Therefore, the following processing is performed in the control data generation unit 72.

As a premise, the control data generator 72 holds MAX, MIN, and APL that have been previously processed. The control data generation unit 72 inputs MAX, MIN, and APL detected by the feature detection unit 11, and compares the MAX, MIN, and APL with the previous APL holding the newly input APL to determine a difference between the changes. This is based on the fact that the signal having the above-mentioned large change almost changes the APL. If the control data generation unit 72 determines that the change difference is smaller than the predetermined value, the control data generation unit 72 uses the MAX, MIN, and APL after passing through the LPF to determine the Gain and Offset corresponding to the input video signal. Find and output. On the other hand, if the control data generation unit 72 determines that the change difference is larger than the predetermined value, the control data generation unit 72 obtains Gain and Offset corresponding to the input video signal using MAX, MIN, and APL that do not pass through the LPF. Output.

By this processing, it is possible to perform an adjustment faithfully corresponding to the input video signal, and to make the change of the input video signal more prominent. The predetermined value can be set arbitrarily in accordance with the level of the input signal. Further, in the control data generation unit 72, whether or not the signal has a large change is determined only by the change of the APL, but it is also possible to determine by using the change of MAX or MIN. Further, when the control data generation unit 72 determines that the change difference is larger than the predetermined value, the control data generation unit 72 appropriately changes the characteristics of the LPF and outputs the MA after passing the changed LPF.
Using X, MIN, and APL, Gain and Offset corresponding to the input video signal may be obtained and output.

As described above, according to the image display apparatus and method according to the seventh embodiment of the present invention, the light source luminance is adjusted with a correlation with the signal amplitude control, and the output image for the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the type and mode of the input video signal are determined, and appropriate adjustment is determined. This makes it possible to appropriately improve the sense of visual contrast for various types and modes of input video signals.

In the seventh embodiment, the case where the configuration of the control data generator 72 is used in the image display devices according to the first and second embodiments has been described.
The same effect can be obtained by using the configuration in the image display devices according to the third to sixth embodiments. Further, the control data generation unit 72 in the seventh embodiment described above.
Is not necessarily a configuration corresponding to all of the above (1) to (3), and may be a configuration corresponding to only one or two of them.

(Eighth Embodiment) Generally, an input video signal is preliminarily subjected to a gamma correction process in order to correct a gamma characteristic of a CRT on the assumption that a CRT is used as a display device. On the other hand, the light receiving type light modulator 17 (for example, a display device used in the present invention)
Since the liquid crystal panel does not have a gamma characteristic like a CRT, contrast adjustment and light source luminance adjustment as described in the first to seventh embodiments are performed on an input video signal that has been subjected to gamma correction processing in advance. And output as it is, an appropriate image display may not be obtained. Therefore, in an eighth embodiment of the present invention, an input video signal that has been subjected to gamma correction processing is subjected to inverse gamma correction processing to perform appropriate contrast adjustment and light source luminance adjustment.

FIG. 11 is a block diagram showing a configuration of an image display device according to the eighth embodiment of the present invention. 11, the image display device according to the eighth embodiment includes a feature detection unit 11, a control data generation unit 12, an input signal processing unit 13, a gamma inverse correction processing unit 81, and a gamma control data generation unit 85. , Light source control unit 16 and light receiving type light modulation unit 17
And The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 11, the image display device according to the eighth embodiment differs from the image display devices according to the first and second embodiments in that a gamma inverse correction processing section 81 and a gamma control data generation section 85 is further added. The other configurations of the image display device according to the eighth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Hereinafter, with further reference to FIG. 12, an image display device according to the eighth embodiment of the present invention will be described.
The following description focuses on components that are different from the image display devices according to the first and second embodiments. FIG. 12 shows the gamma inverse correction processing section 81 and the gamma control data generation section 8 of FIG.
FIG. 5 is a diagram illustrating an example of an inverse gamma characteristic in No. 5;

The gamma inverse correction processing section 81 receives the non-linear output video signal output from the input signal processing section 13 and subjected to the gamma correction processing in advance, and according to the predetermined inverse gamma characteristic shown in FIG. Performs an inverse gamma correction process on the output video signal. This inverse gamma characteristic is completely opposite to the gamma characteristic previously applied to the input video signal (ie,
Gamma characteristic). For example, NTS
In the C standard, gamma = 2.2. Accordingly, a linear output video signal is output from the inverse gamma correction processing unit 81 to the light receiving type light modulation unit 17.

The gamma control data generator 85 receives the APL output from the feature detector 11 and the Offset output from the control data generator 12. Then, the gamma control data generation unit 85 obtains a difference β that becomes an Offset that has been subjected to the gamma inverse correction process from the difference α obtained by the APL and the Offset according to the predetermined inverse gamma characteristic shown in FIG. Output to the control unit 16. The inverse gamma characteristic in the gamma control data generation unit 85 is the same as the inverse gamma characteristic in the gamma inverse correction processing unit 81.

As described above, according to the image display apparatus and method according to the eighth embodiment of the present invention, the light source luminance is adjusted while having a correlation with the signal amplitude control, and the output image for the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the input video signal is subjected to a gamma inverse correction process for canceling a gamma correction process performed in advance, and appropriate contrast adjustment and light source luminance adjustment are performed. As a result, even for an input video signal that has been subjected to gamma correction processing in advance,
Appropriate visual contrast can be improved.

In the eighth embodiment, the inverse gamma correction processor 81 and the gamma control data generator 8
The case where the configuration 5 is used in the image display devices according to the first and second embodiments has been described, but the same applies when the configuration is used in the image display devices according to the third to seventh embodiments. It is possible to achieve the effect of

(Ninth Embodiment) In the eighth embodiment, the case where the gamma inverse correction process is performed after the contrast adjustment and the light source luminance adjustment are performed has been described. Next, according to a ninth embodiment of the present invention, after performing gamma inverse correction processing on an input video signal that has been subjected to gamma correction processing in advance,
In this embodiment, appropriate contrast adjustment and light source luminance adjustment are performed.

FIG. 13 is a block diagram showing the configuration of the image display device according to the ninth embodiment of the present invention. In FIG. 13, the image display device according to the ninth embodiment includes a gamma inverse correction processing unit 91, a feature detection unit 11, a control data generation unit 12, an input signal processing unit 13, a light source control unit 16
And a light receiving type light modulation unit 17. The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 13, the image display device according to the ninth embodiment has a configuration in which a gamma inverse correction processing section 91 is further added to the image display devices according to the first and second embodiments. is there. The other configurations of the image display device according to the ninth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Less than,
An image display device according to a ninth embodiment of the present invention will be described focusing on components different from the image display devices according to the first and second embodiments.

The inverse gamma correction processing section 91 receives a non-linear input video signal that has been subjected to gamma correction processing in advance, and according to a predetermined inverse gamma characteristic (see FIG. 12A).
Inverse gamma correction processing is performed on the input video signal. The inverse gamma characteristic has a characteristic completely opposite to the gamma characteristic applied to the input video signal in advance (that is, cancels out the gamma characteristic), similarly to the eighth embodiment. As a result, a linear input video signal is output from the inverse gamma correction processing section 91 to the feature detection section 11 and the input signal processing section 13.

As described above, according to the image display apparatus and the method according to the ninth embodiment of the present invention, the light source luminance is adjusted with the correlation with the signal amplitude control, and the output image for the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the input video signal is subjected to a gamma inverse correction process for canceling a gamma correction process performed in advance, and appropriate contrast adjustment and light source luminance adjustment are performed. As a result, even for an input video signal that has been subjected to gamma correction processing in advance,
Appropriate visual contrast can be improved. Also, since the gamma inverse correction processing is performed at the stage of inputting the signal, it is not necessary to include the gamma control data generation unit 85 in the configuration as in the eighth embodiment.

In the ninth embodiment, the case where the configuration of the inverse gamma correction processing section 91 is used in the image display devices according to the first and second embodiments has been described. The same effects can be obtained even when used in the image display devices according to the third to seventh embodiments.

(Tenth Embodiment) As a display device applicable to the light receiving type light modulation section 17 of the present invention, a panel using liquid crystal is considered. However, this liquid crystal panel has a characteristic that it responds quickly when the luminance change (APL change) of the video signal is large, and responds slowly when it is small. For this reason, if constant control is performed for all luminance changes, there may be cases where it is not possible to perform appropriate light source luminance adjustment suitable for an image. Therefore, in a tenth embodiment of the present invention, appropriate light source luminance adjustment suitable for a video is performed according to a luminance change of a video signal, that is, a response speed of a liquid crystal panel.

FIG. 14 is a block diagram showing a configuration of an image display device according to the tenth embodiment of the present invention. FIG.
In the image display device according to the tenth embodiment, the feature detection unit 11, the control data generation unit 12, the input signal processing unit 13, the control data correction unit 101, and the light source control unit 1
6 and a light receiving type light modulation section (liquid crystal panel) 17.
The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 14, the image display device according to the tenth embodiment has a configuration in which a control data correction unit 101 is further added to the image display devices according to the first and second embodiments. . The other configurations of the image display device according to the tenth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the configurations. The description is omitted. Hereinafter, the image display device according to the tenth embodiment of the present invention will be described mainly with reference to FIG. 15, focusing on components different from the image display devices according to the first and second embodiments. FIG. 15 is a timing chart illustrating an example of a correction process performed by the control data correction unit 101 in FIG.

First, with reference to FIG.
Light source luminance adjustment in the image display device according to the embodiment will be described. When the APL change of the video signal is small (FIG. 15)
(A) of the signal (A), the APL change of the actual image in the light receiving type light modulation unit 17 is delayed (the signal B of FIG. 15A changes over three fields). When the APL change of the video signal is large (signal A in FIG. 15B),
The APL change of the actual image in the light receiving type light modulation unit 17 becomes faster (in the case of the signal B in FIG. 15B, the change is completed in one field). On the other hand, the luminance change of the light source 18 changes in a predetermined period in accordance with the Offset (signal C in FIGS. 15A and 15B) output from the control data generation unit 12 regardless of the APL change. (Figure 15
(D) of (a) and (b). Therefore, the change in the APL of the video signal in the light receiving type light modulation unit 17 does not match the change in the brightness adjustment of the light source 18 (FIGS. 15A and 15B).
, The signal B and the signal D do not match).

Therefore, the control data correction unit 101 performs the following processing. The control data correction unit 101 is provided in advance with a filter (for example, an LPF) having a time constant corresponding to the response speed in the light receiving type optical modulation unit 17. The control data correction unit 101 outputs the O
ffset is input and the value is detected. When the value of Offset is large, the control data correction unit 101 shortens the time constant of the filter, and when the value of Offset is small, increases the time constant of the filter. (Signal E in FIGS. 15A and 15B). Thereby, the light receiving type light modulating unit 17
A change in the APL of the video signal and the change in the brightness adjustment of the light source 18 at the time of (a) and (b) in FIG.
, The signal B and the signal F match).

As described above, according to the image display apparatus and method according to the tenth embodiment of the present invention, the light source luminance adjustment is performed with a correlation with the signal amplitude control, and the output video signal for the input video signal is adjusted. In absorbing the APL fluctuation of the signal, appropriate light source luminance adjustment is performed in accordance with the response speed of the luminance change (APL change) of the video signal in the light receiving type optical modulator 17. Thereby, even when a liquid crystal panel or the like is used as the light receiving type light modulation section 17, it is possible to improve the sense of contrast appropriate for the video signal.

In the tenth embodiment,
The configuration of the control data correction unit 101 is the same as that of the first and second
Although the case where the configuration is used for the image display device according to the embodiment is described, the same effect can be obtained by using the configuration for the image display device according to the third to ninth embodiments.

(Eleventh Embodiment) In the first to tenth embodiments, the case where the contrast adjustment and the light source luminance adjustment are performed for the system displaying one screen has been described. However, the contrast adjustment and the light source luminance adjustment of the present invention can be similarly applied to a system that displays two screens on one light receiving type light modulation unit such as a personal computer (PC). is there. Therefore, in an eleventh embodiment of the present invention, when the contrast adjustment and the light source luminance adjustment are used in a system that displays two screens, the sense of contrast is improved.

FIG. 16 is a block diagram showing a configuration of an image display device according to the eleventh embodiment of the present invention. FIG.
In the image display device according to the eleventh embodiment, the feature detection unit 11, the control data generation unit 12, the input signal processing unit 13, the light source control unit 16, the correction data generation unit 11,
1, a signal amplitude adjustment unit 112, a MIX 113, and a light receiving type light modulation unit 17. Also, the light receiving type light modulating unit 17
Includes a light source 18.

As shown in FIG. 16, the image display device according to the eleventh embodiment differs from the image display devices according to the first and second embodiments in that a correction data generator 111, a signal amplitude adjuster 112, and a MIX 113 Is further added. The other configuration of the image display device according to the eleventh embodiment is the same as the configuration of the image display device according to the first and second embodiments, and the same reference numerals are given to the same components. The description is omitted. Hereinafter, the image display device according to the eleventh embodiment of the present invention will be described mainly with reference to FIGS. 17 and 18, focusing on components different from those of the image display devices according to the first and second embodiments. I do. FIG. 17 is a diagram showing an example in which two screens are displayed on the light-receiving light modulator 17 of FIG. FIG. 18 is a diagram illustrating an example of a schematic process performed by an image display device according to an eleventh embodiment of the present invention on a certain input video signal.

Now, when two screens (windows) as shown in FIG. 17 are displayed on the light receiving type light modulator 17,
Consider a case where contrast adjustment and light source luminance adjustment are performed on the first screen. In this case, a video signal processing circuit (not shown) such as a television receiver or a computer device
Corresponds to a first input video signal, which is a video signal corresponding to the first screen (screen to be controlled), to the feature detection unit 11 and the input signal processing unit 13, and corresponds to a second screen (screen not to be controlled). The second input video signal, which is a video signal, is output to the signal amplitude adjustment unit 112. Further, the video signal processing circuit outputs to the MIX 113 a window switching signal which indicates which screen is the output video signal.

First, the feature detection unit 11, control data generation unit 12, input signal processing unit 13, and light source control unit 16 have been described for the first input video signal in the first or second embodiment. The processing is performed to adjust the contrast and the luminance of the light source (FIG. 18A).

[0098] The correction data generator 111 receives the Offset output from the control data generator 12. And
The correction data generation unit 111 determines, based on the Offset,
The second light source luminance adjustment performed on the first input video signal does not affect the second input video signal (that is, the light source luminance adjustment effect is canceled). A signal for correcting the amplitude of the input video signal is generated. The signal amplitude adjustment unit 112 includes the correction data generation unit 11
1 receives a correction signal and a second input video signal, and amplifies or attenuates the amplitude of the second input video signal according to the correction signal. Here, the signal amplitude adjustment unit 112 amplifies or attenuates the second input video signal based on the black level (FIG. 18B). The MIX 113 receives the first input video signal after the contrast adjustment output from the input signal processing unit 13 and the second input video signal after the contrast correction output from the signal amplitude adjustment unit 112. The light receiving type light modulation unit 1 is provided in accordance with the given timing.
The output video signal to be output to 7 is switched.

By this processing, the amplitude of the second input video signal can be corrected so as to always cancel the luminance adjustment of the light source 18 performed on the first input video signal (FIG. 18B )), The effects of the contrast adjustment and the light source luminance adjustment performed on the first screen do not affect the second screen.

As described above, according to the image display apparatus and method according to the eleventh embodiment of the present invention, in the system for displaying two screens, the contrast adjustment and the light source luminance adjustment are performed on the control target screen. For the screen not to be controlled, correction is performed so as to cancel the light source luminance adjustment effect. As a result, even in a system that performs two-screen display, it is possible to appropriately improve the sense of visual contrast without discomfort in both screens.

In the eleventh embodiment,
The case where the configurations of the correction data generation unit 111, the signal amplitude adjustment unit 112, and the MIX 113 are used in the image display devices according to the first and second embodiments has been described. The same effect can be obtained even when used in the image display device according to the embodiment. Also,
In the eleventh embodiment, the signal amplitude adjustment unit 11
The criteria by which 2 amplifies or attenuates the second input video signal are:
Described as being black level. However, this criterion
The APL level or an arbitrary level can be set as a reference by performing feature detection (similar to the feature detection unit 11) on the second input video signal without being limited to the black level. .

(Twelfth Embodiment) In the eleventh embodiment, the contrast adjustment and the light source luminance adjustment described in the first to tenth embodiments are performed by forming two screens on one light receiving type light modulator. The case of using the display system has been described. Therefore, a description will now be given of a case where the contrast adjustment and the light source luminance adjustment according to the present invention are applied to a system that displays three or more screens so as to improve the sense of contrast. In the following twelfth embodiment, the contrast adjustment and the light source luminance adjustment of the present invention are performed as follows.
A case where the present invention is used in a system that displays three screens will be described as an example.

FIG. 19 is a block diagram showing a configuration of an image display device according to the twelfth embodiment of the present invention. FIG.
In the image display device according to the twelfth embodiment, the first feature detection unit 11 and the first control data generation unit 12
A first input signal processing unit 13, a light source control unit 16,
Second feature detection unit 121 and second control data generation unit 1
22, a second input signal processing unit 13, a correction data generation unit 124, a signal amplitude adjustment unit 125, and a MIX 123
And a light receiving type light modulation unit 17. The light receiving type light modulation unit 17 includes a light source 18.

As shown in FIG. 19, the image display device according to the twelfth embodiment is different from the image display devices according to the first and second embodiments in that a second feature detection section 121 and a second control The data generator 122, the second input signal processor 13, the correction data generator 124, the signal amplitude adjuster 125, the MI
X123 is further added. The other configurations of the image display device according to the twelfth embodiment are the same as the configurations of the image display devices according to the first and second embodiments, and the same reference numerals are given to the same components. The description is omitted. In addition, the first feature detection unit 11, the first control data generation unit 12, and the first input signal processing unit 13 of the image display device according to the twelfth embodiment are respectively different from the first or second embodiment. Since the configuration is the same as that of the feature detection unit 11, control data generation unit 12, and input signal processing unit 13 of the image display device according to the above, the same reference numerals are assigned. Further, the second input signal processing unit 13 has the same configuration as the input signal processing unit 13 of the image display device according to the first or second embodiment, and thus the same reference numeral is assigned. . Hereinafter, the image display device according to the twelfth embodiment of the present invention will be described focusing on components different from those of the image display devices according to the first and second embodiments.

Now, consider a case in which, when three screens (first to third screens) are displayed on the light receiving type light modulator 17, contrast adjustment and light source luminance adjustment are performed on the first screen. . In this case, a video signal processing circuit (not shown) such as a television receiver or a computer device converts a first input video signal, which is a video signal corresponding to a first screen (a control target screen), into a first characteristic. A second input video signal, which is a video signal corresponding to a second screen (a screen not to be controlled), is supplied to the detection unit 11 and the first input signal processing unit 13 by the second feature detection unit 121 and the second input signal. The signal processing unit 13 sends a third signal (video signal corresponding to the third screen (non-control target screen))
Are output to the signal amplitude adjusting unit 125, respectively. Further, the video signal processing circuit outputs a window switching signal for giving an output video signal regarding a screen to M
Output to IX123.

First, the first feature detecting section 11, the first control data generating section 12, the first input signal processing section 13 and the light source control section 16 apply the first input video signal to the first input video signal. Alternatively, the contrast adjustment and the light source luminance adjustment are performed by performing the processing described in the second embodiment.

Next, like the first feature detecting section 11, the second feature detecting section 121 outputs the MA of the second input video signal.
X, MIN and APL are detected respectively. The second control data generation unit 122 receives the MAX, MIN, and APL detected by the second feature detection unit 121, and the Offset output by the first control data generation unit 12. Then, the second control data generation unit 122 outputs the light source control unit 1
6 and the maximum amplitude of the second input video signal is reduced by the second input signal processing unit 13.
The gain for amplifying to a predetermined level within the output dynamic range of the DC level adjustment unit 13B is obtained. Further, the second control data generation unit 122 sets an Offset that gives the DC level at which the second input video signal amplified by the signal amplitude adjustment unit 13A of the second input signal processing unit 13 falls within the output dynamic range. Ask.
The obtained Gain is output to the signal amplitude adjustment unit 13A of the second input signal processing unit 13, and Offset is output to the DC level adjustment unit 13B of the second input signal processing unit 13, respectively. The second input signal processing unit 13 performs the same processing as the input signal processing unit 13 described in the first or second embodiment.

The correction data generator 124 receives the Offset output from the first control data generator 12. Then, based on the Offset, the correction data generation unit 124 controls the influence of the light source luminance adjustment performed on the first input video signal so as not to affect the third input video signal (ie, the light source A signal for correcting the amplitude of the third input video signal is generated so that the brightness adjustment effects are canceled out, respectively. The signal amplitude adjustment unit 125 receives the correction signal output from the correction data generation unit 124 and the third input video signal, and amplifies or attenuates the amplitude of the third input video signal according to the correction signal. Here, the signal amplitude adjustment unit 12
5 amplifies or attenuates the third input video signal based on the black level. The MIX 123 is the first input signal processing unit 1
3, the first input video signal after the contrast adjustment output from the second input signal processing unit 13, the second input video signal after the contrast correction output from the second input signal processing unit 13, and the signal amplitude adjustment unit 125.
And outputs the third input video signal after the contrast correction output from the optical input device, and switches the output video signal to be output to the light receiving type light modulator 17 in accordance with the timing given by the window switching signal.

By this processing, the amplitudes of the second and third input video signals can be corrected so as to always cancel the luminance adjustment of the light source 18 performed on the first input video signal. A unique contrast adjustment can be performed on the second input video signal. As a result, the effects of the contrast adjustment and the light source luminance adjustment performed on the first screen are not affected on the second and third screens, and the unique contrast adjustment is performed on the second screen. It can be performed.

As described above, according to the image display apparatus and method according to the twelfth embodiment of the present invention, in a system for displaying three or more screens, the contrast adjustment and the light source luminance adjustment are performed for the control target screen. And perform correction to cancel the light source brightness adjustment effect for the screens not to be controlled, and for the necessary non-controllable screens, use a unique contrast adjustment that is different from the adjustment performed for the screens to be controlled. Do. As a result, even in a system for displaying three or more screens, it is possible to appropriately improve the sense of visual contrast without discomfort on all screens.

In the twelfth embodiment,
Second feature detection unit 121, second control data generation unit 12
2, the second input signal processing unit 13, the correction data generation unit 12
4. The case where the configurations of the signal amplitude adjusting unit 125 and the MIX 123 are used in the image display devices according to the first and second embodiments has been described.
The same effect can be obtained even when used in the image display device according to the first embodiment. Further, in the twelfth embodiment, the case where the contrast adjustment and the light source luminance adjustment of the present invention are used in a system that displays three screens has been described as an example. However, three or more screens are displayed. Similar effects can be obtained even when used in a system. In this case, when there are a plurality of screens for which unique contrast adjustment needs to be performed, the second feature detecting unit 121 and the second
A plurality of configurations equivalent to the control data generation unit 122 and the second input signal processing unit 13 may be used.

(Thirteenth Embodiment) In the first to twelfth embodiments, the Off which the control data generators (or the first control data generators) 12, 42, 52 and 72 output
The case where the light source control unit 16 is controlled based on the set has been described. Next, in the thirteenth embodiment, Off
The light source control unit 16 is controlled using data other than set.

FIG. 20 is a block diagram showing the configuration of the image display device according to the thirteenth embodiment of the present invention. FIG.
In the image display device according to the thirteenth embodiment, the feature detection unit 11, the first control data generation unit 12, the input signal processing unit 13, the output signal feature detection unit 134, and the second
, A light source control unit 16, and a light receiving type light modulation unit 17. Also, the light receiving type light modulating unit 17
Includes a light source 18.

As shown in FIG. 20, the image display device according to the thirteenth embodiment is different from the image display devices according to the first and second embodiments in that an output signal feature detection section 134 and a second control data The configuration is such that a generation unit 135 is further added. The components of the image display device according to the thirteenth embodiment are the same as those of the image display devices according to the first and second embodiments, and the same reference numerals are given to the components. The description is omitted. The first control data generation unit 12 of the image display device according to the thirteenth embodiment
Has the same configuration as that of the control data generator 12 of the image display device according to the first or second embodiment, and thus has the same reference numeral. Hereinafter, the image display device according to the thirteenth embodiment of the present invention will be described focusing on processing operations different from those of the image display devices according to the first and second embodiments.

The output signal characteristic detecting section 134 receives the output video signal output from the input signal processing section 13. And
The output signal characteristic detecting section 134 detects the average luminance level (hereinafter, referred to as APL2) of the output video signal and outputs the same to the second control data generating section 135, similarly to the characteristic detecting section 11. The second control data generation unit 135 receives the APL output from the feature detection unit 11 and the APL2 output from the output signal feature detection unit 134. Then, the second control data generation unit 135 calculates Offset by calculating APL2-APL, and outputs the result to the light source control unit 16.

As described above, according to the image display apparatus and method according to the thirteenth embodiment of the present invention, the light source 1 is provided with a correlation with the signal amplitude control performed by the input signal processing unit 13.
8 to adjust the APL variation of the output video signal with respect to the input video signal. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18.

Note that in the thirteenth embodiment,
The case where the configurations of the output signal feature detection unit 134 and the second control data generation unit 135 are used in the image display devices according to the first and second embodiments has been described. Similar effects can be obtained even when used in the image display device according to the twelfth embodiment.

(Fourteenth Embodiment) In the thirteenth embodiment, the characteristic (APL2) of the output video signal is detected by using the output signal characteristic detecting section 134, and the second control data generating section 135 detects the APL2. Of based on and APL2
The case where the fset is generated and output to the light source control unit 16 has been described. Further, in the fourteenth embodiment, the feature (APL2) is detected from a source other than the output video signal, and the feature (APL2) is detected.
set is generated.

FIG. 21 is a block diagram showing the configuration of the image display device according to the fourteenth embodiment of the present invention. FIG.
In the image display device according to the fourteenth embodiment, the feature detection unit 11, the first control data generation unit 12, the input signal processing unit 13, the feature data generation unit 144, and the second control data generation A light source control unit 16 and a light receiving type light modulation unit 17 are provided. Also, the light receiving type light modulating unit 17
Includes a light source 18.

As shown in FIG. 21, the image display device according to the fourteenth embodiment is different from the image display devices according to the first and second embodiments in that a feature data generation unit 144 and a second control data generation unit are provided. In this configuration, a portion 145 is further added. The components of the image display device according to the fourteenth embodiment are the same as those of the image display devices according to the first and second embodiments, and the same reference numerals are given to the components. The description is omitted. Also, the first control data generation unit 12 of the image display device according to the fourteenth embodiment
Has the same configuration as that of the control data generator 12 of the image display device according to the first or second embodiment, and thus has the same reference numeral. Hereinafter, the image display device according to the fourteenth embodiment of the present invention will be described focusing on processing operations different from those of the image display devices according to the first and second embodiments.

The feature data generation unit 144 includes the feature detection unit 1
The MAX, MIN, and APL detected by the first control data generation unit 12 and the Gain obtained by the first control data generation unit 12 are input. Then, the feature data generation unit 144 determines that MAX, MIN, A
An average luminance level (hereinafter, referred to as APL2) in the output video signal is obtained based on PL and Gain, and is output to the second control data generation unit 145. The second control data generation unit 145 outputs the APL output from the feature detection unit 11.
And APL2 output by the feature data generation unit 144. Then, the second control data generation unit 145
Offset is obtained by calculating L2-APL, and is output to the light source control unit 16.

As described above, according to the image display apparatus and method of the fourteenth embodiment of the present invention, the light source 1 is provided with a correlation with the signal amplitude control performed by the input signal processing unit 13.
8 to adjust the APL variation of the output video signal with respect to the input video signal. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18.

In the fourteenth embodiment,
The case where the configurations of the feature data generation unit 144 and the second control data generation unit 145 are used in the image display devices according to the first and second embodiments has been described. The same effect can be obtained even when used in the image display device according to the embodiment.

(Fifteenth Embodiment) In the first to fourteenth embodiments, in order to obtain an output video signal, the amplification of the input video signal and the level shift of the DC level are performed by the signal amplitude adjustment units 13A and 13C. This is performed separately in the level adjustment unit 13B. This is based on the control data generator (or the first
APL in the control data generators 12, 42, 72
This is because the gain is determined based on the reference. Therefore, in the fifteenth embodiment, G
ain is obtained.

FIG. 22 is a block diagram showing a configuration of an image display device according to the fifteenth embodiment of the present invention. FIG.
In the image display device according to the fifteenth embodiment, a feature detection unit 151, a first control data generation unit 152,
A signal amplitude adjustment unit 153, a feature data generation unit 154,
Second control data generation unit 155 and light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

The operation (image display method) of each component of the image display device according to the fifteenth embodiment of the present invention will now be described with reference to FIG.
Will be further described. FIG. 23 is a diagram illustrating an example of a schematic process performed by an image display device according to a fifteenth embodiment of the present invention on a certain input video signal.

First, a video signal output from a video signal processing circuit (not shown) such as a television receiver or a computer device is used as an input video signal as a feature detector 151 and a signal amplitude adjuster which is an input signal processor. 153 are respectively input. The feature detection unit 151 calculates the M of the input video signal.
AX, MIN and APL are detected respectively. In addition,
MAX, MIN, and AP performed by the feature detection unit 151
Since the detection of L is a conventionally performed process, a detailed description thereof is omitted here.

The first control data generator 152 inputs MAX and MIN detected by the feature detector 151,
serves as a reference in the amplification based on Gain of ain Toko level (hereinafter, referred to as Base (base)) and a, determined as follows. Now, consider a case where the feature detecting unit 151 detects MAX, MIN, and APL as shown in FIG. 23A with respect to an input video signal.

First, the first control data generator 152
The maximum amplitude of the input video signal (difference between MAX and MIN)
The gain for amplifying the signal processing range of the processing circuit, that is, the dynamic range (specifically, the output dynamic range of the signal amplitude adjusting unit 153) is obtained according to the following equation. Gain = dynamic range width / (MAX-MIN) For example, in FIG. 23, when the maximum amplitude of the input video signal is 67% of the dynamic range width (FIG. 23)
(A)), Ga obtained by the first control data generation unit 152
in becomes about 1.5 times (FIG. 23B).

Next, the first control data generator 152
Base, which is the only level of the amplified input video signal whose level does not fluctuate in order to keep the input video signal after amplification performed by the signal amplitude adjustment unit 153 within the output dynamic range, from MAX and MIN and the gain obtained above.
Is calculated according to one of the following equations. Base = Gain × MIN / (Gain−1) Base = (Gain × MAX−dynamic range)
/ (Gain-1) The obtained Gain and Base are output to the signal amplitude adjustment unit 153 and the feature data generation unit 154.

The signal amplitude adjustment section 153 receives the input video signal and the gain and base output from the first control data generation section 152. Then, the signal amplitude adjusting unit 15
No. 3 amplifies the input video signal in accordance with Gain with reference to Base (FIG. 23B). As a result, the input video signal is amplified to the full output dynamic range of the signal amplitude adjuster 153 and output. The amplified input video signal (hereinafter, referred to as an output video signal) is output to the light receiving type light modulator 157 and displayed as an image.

The feature data generation unit 154 includes the feature detection unit 1
APL detected by the first control data generation unit 15
2 inputs the obtained Gain and Base. Then, based on APL, Gain, and Base, feature data generation section 154 calculates an average luminance level (APL2) in the output video signal according to the following equation. APL2 = Base + (APL−Base) × Gain This APL2 is output to the second control data generator 155.

The second control data generator 155 includes the APL output from the feature detector 151 and the feature data generator 154.
And the APL2 output from. Then, the second control data generation unit 155 calculates a DC level difference (= APL2-APL) of the average luminance level, and outputs it to the light source control unit 156.

The light source controller 156 controls the visual luminance level of the output video signal to be equal to the luminance level of the input video signal according to the DC level difference output from the second control data generator 155, that is, Type light modulator 1
The APL when the image is displayed on the display 57 is the APL in the input video signal.
A predetermined luminance adjustment is performed on the light source 158 so as to be the same as the PL (FIG. 23C). As described above, by absorbing the variation of the APL generated by the signal amplitude adjusting unit 153, the brightness of the light source 158 is reduced, and the visual brightness level is further reduced with respect to the black level. Is up. Further, as for the white level, the visual white peak becomes higher by increasing the luminance of the light source 158, and as a result, a bright portion becomes more prominent and the sense of contrast is improved.

As described above, according to the image display apparatus and the method according to the fifteenth embodiment of the present invention, the brightness adjustment of the light source 158 is performed with the correlation with the signal amplitude control performed by the signal amplitude adjustment unit 153. To absorb the APL fluctuation of the output video signal with respect to the input video signal. Thereby, the light source 1
The visual contrast can be improved without increasing the average power consumption of 58.

Note that, in the fifteenth embodiment,
A case has been described in which a gain for amplifying up to the dynamic range width is set as the gain required by the first control data generation unit 152. Thus, it is similarly possible to set the gain to be less than the dynamic width that is visually most effective.

(Sixteenth Embodiment) When the process of extending the signal amplitude or the process of increasing the luminance of the light source as described in the fifteenth embodiment is performed, the noise component of the input video signal is also increased. And image quality is degraded. Therefore, the sixteenth embodiment of the present invention is designed to reduce the noise component when the above processing is performed.

FIG. 24 is a block diagram showing the configuration of the image display device according to the sixteenth embodiment of the present invention. FIG.
In the image display device according to the sixteenth embodiment, the feature detection unit 151, the first control data generation unit 152,
Noise control data generation section 161 and noise reduction section 162
, A signal amplitude adjustment unit 153, and a feature data generation unit 154
, A second control data generator 155, and a light source controller 15
6 and a light receiving type light modulator 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 24, the image display device according to the sixteenth embodiment further includes a noise control data generation unit 161 and a noise reduction unit 162 in the image display device according to the fifteenth embodiment. Configuration. The first
Other configurations of the image display device according to the sixth embodiment are the same as the configurations of the image display device according to the fifteenth embodiment, and the same reference numerals are given to the same components and description thereof will be omitted. Hereinafter, the image display device according to the sixteenth embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

The noise control data generator 161 receives the Gain output from the first control data generator 152 and the DC level difference output from the second control data generator 155. Then, the noise control data generation unit 161
ain and the level of the DC level difference, the amount of noise that is increased by the signal processing is determined, and a predetermined noise reduction signal corresponding to the amount of noise is generated.
62.

The noise reduction section 162 receives the input video signal and the noise reduction signal output from the noise control data generation section 161 and reduces noise components from the input video signal according to the noise reduction signal. As a configuration of the noise reduction unit 162, for example, a noise filter, a contour correction circuit, or the like can be considered. When the noise reduction unit 162 is configured by a noise filter, a method of controlling the level of filtering in accordance with the noise reduction signal can be considered (specifically, the threshold value for filtering is increased in proportion to the increase in the amount of noise). Do). Noise reduction unit 16 in contour correction circuit
In the case of No. 2, a method of controlling the contour correction level or the coring level in accordance with the noise reduction signal can be considered (specifically, the contour correction level is reduced in proportion to the increase in the noise amount). Or increase the level of coring). Then, the input video signal subjected to the noise reduction is output to the signal amplitude adjusting unit 153, and thereafter, the same processing as in the fifteenth embodiment is performed.

As described above, according to the image display apparatus and the method according to the sixteenth embodiment of the present invention, the light source luminance is adjusted with the correlation with the signal amplitude control, and the output video with respect to the input video signal is adjusted. In absorbing the APL fluctuation of the signal, according to the signal amplitude control and the light source luminance adjustment to be performed,
Reduce the noise component to be expanded. This makes it possible to improve the sense of visual contrast without increasing the noise component and without increasing the average power consumption of the light source 158.

In the noise control data generator 161 of the sixteenth embodiment, it is also possible to suppress the color gain from being excessively increased according to the value of the gain and DC level difference. It is also possible to determine the amount of noise that increases due to signal processing in consideration of the γ characteristics of the liquid crystal in addition to the gain and DC levels.

(Seventeenth Embodiment) Now, with respect to an input video signal whose whole image contains a small area near black in a bright image, the light source luminance is increased as described in the fifteenth embodiment. When the processing is performed, floating of the black level occurs. Therefore, in a seventeenth embodiment of the present invention, the floating of the black level when the light source luminance is high is reduced, and the sense of contrast is improved.

FIG. 25 is a block diagram showing the configuration of the image display device according to the seventeenth embodiment of the present invention. FIG.
In the image display device according to the seventeenth embodiment, the feature detection unit 151, the data determination unit 171, the first control data generation unit 172, the signal amplitude adjustment unit 153, the feature data generation unit 154, Second control data generator 155
, A light source control unit 156 and a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 25, in the image display device according to the seventeenth embodiment, the first control data generator 152 of the image display device according to the fifteenth embodiment is replaced with the first control data generator. 172, and a data determination unit 171
Is added. Note that the other configuration of the image display device according to the seventeenth embodiment is the same as the configuration of the image display device according to the fifteenth embodiment, and the configuration is denoted by the same reference numeral and will be described. Omitted. Hereinafter, the image display device according to the seventeenth embodiment of the present invention will be described mainly with reference to FIG. 26, focusing on components different from the image display device according to the fifteenth embodiment. FIG.
FIG. 61 is a view for explaining an example of an outline of a process performed by an image display device according to a seventeenth embodiment of the present invention for a certain input video signal.

The data judging section 171 receives the input video signal, and obtains the number CNT of pixels of the input video signal having a luminance level equal to or lower than a predetermined luminance level. This luminance level is a reference level for determining how much the pixel on the black level side is included in the entire screen, and can be arbitrarily determined according to the image quality to be obtained. Therefore, CNT is
This is the number of pixels on the black level (low luminance level) side determined according to the luminance level. The unit of the CNT can be arbitrarily determined according to the processing purpose, and may be, for example, a unit of one pixel or a unit of a rectangular area including a plurality of pixels. Note that, in the data determination unit 171,
If the number of pixels is detected for each signal level over the entire signal level, processing accuracy can be improved.

The first control data generator 172 receives the MAX and MIN detected by the feature detector 151 and the CNT output by the data determiner 171 and inputs Gain and Ba.
is determined as follows.

First, the first control data generator 172
Similar to the first control data generation unit 152, a Gain for amplifying the maximum amplitude of the input video signal (FIG. 26A) to the dynamic range width, and a Gain for amplifying the input video signal whose level does not fluctuate. Base, which is the level of, is obtained (FIG. 26B). Next, the first control data generation unit 172 determines whether or not the input video signal has few signals on the black level side and low gradation based on Base and CNT. That is, the first control data generator 1
In the case 72, when the Base is higher than the predetermined reference level and the CNT is lower than the predetermined reference number, it is determined that the input video signal has few signals on the black level side and low gradation. The reference level and the reference number can be arbitrarily determined according to the image quality to be obtained.

Then, the first control data generator 172
When it is determined in the above determination that the input video signal is a signal having a small number of black level signals and a low gradation, it is already determined that the predetermined black level signal in the amplified video signal is collapsed by the dynamic range. Ba
The DC level of se is increased (FIG. 26 (c)). Note that B
The amount by which to increase the DC level of ase can be arbitrarily determined according to the image quality to be obtained. Then, the first control data generation unit 172 outputs the Base having raised the DC level.
With the signal amplitude adjustment unit 153 and the feature data generation unit 15
4 is output. As a result, it is possible to crush low-luminance portions having few gradations and tighten the black level side. Also,
Since the APL is reduced by crushing the low-luminance portion, the white peak level visually increases when the light source luminance is adjusted (FIG. 26D).

Note that the first control data generator 172
If it is not determined that the input video signal is a signal having a small black level and a low gradation, the Base that has already been obtained is output to the signal amplitude adjustment unit 153 and the feature data generation unit 154 as it is. Thereafter, the same processing as in the fifteenth embodiment is performed.

As described above, according to the image display apparatus and the method according to the seventeenth embodiment of the present invention, the light source luminance is adjusted while having a correlation with the signal amplitude control, and the output video signal with respect to the input video signal is output. In absorbing the APL fluctuation of the signal, a process of crushing the gradation of the low luminance portion is performed on the input video signal in which the black level floats. This makes it possible to tighten the black level and increase the white peak level even for an input video signal that includes a black area image with a small area in a bright image as a whole, thereby improving the sense of visual contrast. be able to.

In the seventeenth embodiment,
Data determination unit 171 and first control data generation unit 17
The case where the configuration 2 is used in the image display device according to the fifteenth embodiment has been described. However, the same effect can be obtained by using the configuration in the image display device according to the sixteenth embodiment. It is possible. In the seventeenth embodiment, when it is determined that the number of signals on the black level is small, the process of crushing the dynamic range on the black side by lowering the DC level of Base is performed. Also, for example, the same effect can be obtained by performing processing of gently setting the γ characteristic on the black side and sharpening the γ characteristic on the white side to crush the black side and extend the white side. Further, as described in the seventeenth embodiment,
When the gain calculated as a standard is used, the black side is crushed, so that the white side has a margin for the dynamic range. Therefore, in order to eliminate this margin and use the dynamic range more effectively, a large Gain considering the black level crushing is calculated, and this Gain is calculated.
It is also possible to use in for control.

(Eighteenth Embodiment) On the other hand, the above-described fifteenth embodiment is applicable to an input video signal in which the light source 158 is brightened to reduce the number of effective portions (for example, a black image dominates the majority). Even when the processing for increasing the light source luminance as described in (1) is performed, the floating of the black level occurs. Therefore, in the eighteenth embodiment of the present invention, the change of the light source luminance is suppressed for the input video signal as described above, the floating of the black level is reduced, and the sense of contrast is improved.

FIG. 27 is a block diagram showing the structure of the image display device according to the eighteenth embodiment of the present invention. FIG.
In the image display device according to the eighteenth embodiment, the feature detection unit 151, the data determination unit 181, the first control data generation unit 152, the signal amplitude adjustment unit 153, the feature data generation unit 154, Second control data generator 185
, A light source control unit 156 and a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 27, in the image display device according to the eighteenth embodiment, the second control data generator 155 of the image display device according to the fifteenth embodiment is replaced with the second control data generator. 185 instead of the data determination unit 181
Is added. Note that the other configuration of the image display device according to the eighteenth embodiment is the same as the configuration of the image display device according to the fifteenth embodiment, and the configuration is denoted by the same reference numeral and described. Omitted. Hereinafter, an image display device according to the eighteenth embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

The data determining section 181 receives the input video signal, extracts a bright area from the input video signal, and determines whether the bright area is larger or smaller than a predetermined value.
Output to the second control data generator 185. Here, as a method of extracting and determining a bright area performed by the data determination unit 181, for example, first, the MAX of the input video signal is detected, and the MAX and an area indicating a predetermined MAX approximate value are extracted. A method of determining whether an area is equal to or larger than a predetermined area, a method of determining whether the number of pixels included in the area is equal to or larger than a predetermined number, or the like can be considered.

The second control data generation unit 185 includes the APL output from the feature detection unit 151 and the feature data generation unit 154.
And the determination result output from the data determination unit 181 are input. Then, the second control data generator 185 first calculates the DC level difference between APL and APL2, and then changes the calculated DC level difference based on the determination result. Here, the second control data generation unit 185 determines that the light source 158
The DC level difference is changed so that the luminance level of the image data becomes low. The DC level difference changed based on the determination result is output to the light source control unit 156, and thereafter, the first
Processing similar to that of the fifth embodiment is performed.

As described above, according to the image display apparatus and the method according to the eighteenth embodiment of the present invention, the brightness of the light source is adjusted with the correlation with the signal amplitude control, and the output for the input video signal is adjusted. In absorbing the APL fluctuation of the video signal, a process of lowering the brightness of the light source 158 is performed on an input video signal in which the black level is conspicuous because there are few bright areas. As a result, the black level can be reduced even for an input video signal having a small number of bright regions, and the sense of visual contrast can be improved.

Incidentally, in the eighteenth embodiment,
Data determination unit 181 and second control data generation unit 18
Although the case where the configuration of No. 5 is used in the image display device according to the fifteenth embodiment has been described, the same effect can be obtained by using the configuration in the image display devices according to the sixteenth and seventeenth embodiments. It is possible to play. In the eighteenth embodiment, it is determined whether the bright area of the input video signal is larger or smaller than a predetermined value, and ON / OFF control of the light source 158 is performed based on the result of the determination. , For byte information indicating the size of the bright area,
It is similarly possible to linearly control the light source 158 based on the byte information.

(Nineteenth Embodiment) By the way, there are various display modes such as letterbox and side black in the input video signal. In some cases, character information such as an OSD signal (on-screen display signal) is superimposed on an input video signal. Therefore, if the contrast adjustment and the light source luminance adjustment as described in the fifteenth to eighteenth embodiments are simply performed on such an input video signal, an appropriate image display may not be obtained. appear. Therefore, the nineteenth embodiment of the present invention is also applicable to the OSD for various display modes.
Appropriate contrast adjustment and light source luminance adjustment are also performed on an input video signal on which character information such as a signal is superimposed.

FIG. 28 is a block diagram showing the configuration of the image display device according to the nineteenth embodiment of the present invention. FIG.
In the image display device according to the nineteenth embodiment, the feature detection unit 191, the first control data generation unit 152,
A signal amplitude adjustment unit 153, a feature data generation unit 154,
Second control data generation unit 155 and light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 28, the image display device according to the nineteenth embodiment has a configuration in which the feature detection unit 151 of the image display device according to the fifteenth embodiment is replaced with a feature detection unit 191. Note that the other configuration of the image display device according to the nineteenth embodiment is the same as the configuration of the image display device according to the fifteenth embodiment. Omitted. Hereinafter, the image display device according to the nineteenth embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

The feature detector 191 receives an input video signal, and first determines the display mode of the input video signal and the presence or absence of an OSD signal. The display mode and the presence / absence of the OSD signal may be determined by the feature detection unit 191 by analyzing the input video signal by itself, or may be provided from the outside. Next, based on the determined display mode, the feature detecting unit 191 determines the areas for detecting MAX, MIN, and APL, respectively. For example, the detection area is an area excluding the upper and lower portions of the screen when the display mode is letterbox, and is an area excluding the left and right portions of the screen when the display mode is side black. Alternatively, when the display mode is letterbox, the detection may be weighted between the upper and lower portions of the screen and the other main portions to perform detection on the entire screen. The detection may be weighted for the portion and the other main portion, and the detection may be performed on the entire screen.

On the other hand, when it is determined that there is an OSD signal,
The feature detection unit 191 excludes a part of the OSD display area (predetermined by the apparatus) from the detection area. And
The feature detecting unit 191 determines that the MA
X, MIN, and APL are detected, and MAX and MIN are output to the first control data generation unit 152.
The PL is output to the feature data generation unit 154 and the second control data generation unit 155.

As described above, according to the image display apparatus and the method according to the nineteenth embodiment of the present invention, the light source luminance is adjusted with the correlation with the signal amplitude control, and the output image with respect to the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the display mode and the OSD display of the input video signal are determined to determine an appropriate detection area. This makes it possible to appropriately improve the sense of visual contrast without being affected by an area that constantly displays a black level such as a letter box or side black or an OSD display area having a high white peak. .

In the nineteenth embodiment,
Although the case where the configuration of the feature detecting unit 191 is used in the image display device according to the fifteenth embodiment has been described, the same applies when the configuration is used in the image display devices according to the sixteenth to eighteenth embodiments. It is possible to achieve the effect of Although the feature detection unit 191 in the nineteenth embodiment has been described to perform both the determination of the display mode and the determination of the presence / absence of the OSD signal, only one of them may be performed. Furthermore, in the nineteenth embodiment, the case where the character information is an OSD signal has been described as an example, but all other character information that hinders improvement in visual contrast is described above. It goes without saying that if the processing is applied, useful effects of the present invention can be obtained.

(Twentieth Embodiment) There are various types and modes of input video signals. Therefore, if the contrast adjustment and the light source luminance adjustment as described in the fifteenth to eighteenth embodiments are simply performed on such an input video signal, an appropriate image display may not be obtained. appear. Therefore, in the twentieth embodiment of the present invention, appropriate contrast adjustment and light source luminance adjustment are performed on input video signals of various types and modes.

FIG. 29 is a block diagram showing the configuration of the image display device according to the twentieth embodiment of the present invention. FIG.
In the image display device according to the twentieth embodiment, the feature detection unit 151, the first control data generation unit 202,
A signal amplitude adjustment unit 153, a feature data generation unit 154,
Second control data generation unit 155 and light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 29, in the image display device according to the twentieth embodiment, the first control data generation unit 152 of the image display device according to the fifteenth embodiment is replaced with the first control data generation unit. 202. The twentieth
Other configurations of the image display device according to the present embodiment are the same as those of the image display device according to the fifteenth embodiment, and the same reference numerals are given to the same components and description thereof will be omitted. Hereinafter, the image display device according to the twentieth embodiment of the present invention will be described focusing on components different from those of the image display device according to the fifteenth embodiment, after classifying the image display device according to the type and aspect of the input video signal. I do.

(1) In the case of a blue-back signal or a signal at the time of mode transition This is because the entire input video signal is used for a blue-back signal of a blue color or a mode transition such as scene switching (for example, fade-in / fade-out). This is a case of a special signal such as a white signal. In the case of such a special signal, there is no need to improve the image quality, and it is preferable to basically display an input signal as it is without performing contrast adjustment and light source luminance adjustment. Therefore, the first control data generation unit 202 performs the following processing.

The first control data generation unit 202 inputs MAX and MIN detected by the feature detection unit 151,
The level difference between AX and MIN is a predetermined value (hereinafter, TH
_LVL) is determined. This is based on the fact that a signal such as the above-described blue-back signal has little difference in level between MAX and MIN. Then, the first control data generation unit 20
When determining that the level difference is larger than TH_LVL, the second calculates and outputs the Gain and Base corresponding to the input video signal as described in the fifteenth embodiment. On the other hand, when the first control data generation unit 202 determines that the level difference is smaller than TH_LVL, it determines that the input video signal is a special signal such as a blue-back signal,
For the calculated Gain and Base, a value with a reduced control effect is output. Specifically, Gain and Base for which adjustment is not performed are respectively referred to as Gain_
Type and Base_Type, and Gain to be output
And Base are Gain_Out and B, respectively.
Assuming that case_Out, the following equation: Gain # Out = Gain # Typ + (Gain-Gain # Typ) * ((MAX-MIN) / TH # L
VL) Base # Out = Base # Typ + (Base-Base # Typ) * ((MAX-MIN) / TH # L
VL) is used to calculate Gain_Out and Base_Out.

By this processing, it is possible to prevent overcorrection due to unnecessary control and reduce power consumption. The predetermined value can be set arbitrarily according to the level of the special signal to be input. In the above description, as a process performed by the first control data generation unit 202, when the level difference between MAX and MIN is smaller than a predetermined value, it is determined that the signal is a special signal, and according to (MAX-MIN). Although the method of gradually increasing the gain by a factor of 1 has been described, it is also possible to use a method of judging a special signal by color or synchronization (for example, not being an interlace signal). It is possible.

(2) In the case of a signal having a change only in a very small area This is because the input video signal has a change in a part of the entire screen, that is, a large part of the image has no large change, This is a case of a signal having a change only in a part of the region. In the case of such a signal, if the contrast adjustment and the light source luminance adjustment are performed under the influence of the changing area, a sense of incongruity may be visually provided in an area that does not greatly change and occupies most of the image. For this reason,
In the case of such a signal, it is preferable that the adjustment value is not largely changed from the adjustment value processed last time, that is, the change between the previous output image and the current output image is preferably reduced. Therefore, the first control data generation unit 202 performs the following processing.

As a premise, the first control data generator 20
2 is the previously processed MAX, MIN, Gain and B
case is held. The first control data generation unit 202 inputs MAX and MIN detected by the feature detection unit 151, and compares the MAX and MIN with the previous Base holding the newly obtained Base to determine the difference between the changes. This is based on the fact that the Base signal hardly changes in the above-described signal having a change only in the minute area. Then, if there is no difference in the change, the first control data generating unit 202
e is calculated from the previously processed Gain and Base and the current M based on the magnitude of the difference, if any.
Gain and Base up to Gain and Base calculated based on AX and MIN are variably output as Gain and Base corresponding to the input video signal. For example, a cyclic low-pass filter (LPF) that passes Gain and Base is provided, and when the difference in change is small, the time constant of the LPF is increased (the amount of change is small), and the difference in change is small. L is large if
The time constant of the PF may be reduced (the amount of change is increased). If the difference between the changes is large, Gai finally calculated based on the current MAX and MIN
may be controlled to converge to n and Base,
Control may be performed so as to converge to a separately determined Gain and Base.

By this processing, although the effect of improving the image quality of the image alone is somewhat reduced, visual discomfort due to unnecessary control can be suppressed, and the connection before and after the image can be expressed naturally. It should be noted that the variable amount according to the difference between the changes can be arbitrarily set in accordance with the level of the input signal. Further, in the first control data generation unit 202, whether or not a signal has a change only in a minute area is determined only by a change in Base, but it is also possible to determine by using a change in MAX or MIN. Further, the first control data generation unit 202 detects that the most part of the image does not change by detecting the histogram data,
The accuracy of the determination can be improved.

(3) In the case of a signal having a large change This is a case where the input video signal is a signal having a large change due to a scene change or the like. Here, even if there is no change in the image, since the input video signal slightly changes on the time axis (due to noise or the like), the adjustment level is changed each time for this minute change. The image flickers and makes it hard to see. Therefore, in general, a low-pass filter (L
PF) to adjust the contrast and the light source luminance after absorbing (smoothing) a minute change to ensure the visibility of the image. However, even in the case of the above-mentioned signal having a large change, if each adjustment is performed after smoothing through the LPF, it is not possible to realize the adjustment faithfully corresponding to the signal. For this reason, it is preferable to perform each adjustment for a signal having a large change without passing through the LPF. Therefore, the first control data generation unit 202 performs the following processing.

As a premise, the first control data generator 20
2 holds the previously processed MAX and MIN, respectively. The first control data generation unit 202 inputs MAX and MIN detected by the feature detection unit 151, and compares the MAX and MIN with the previous Base holding the newly obtained Base to determine the difference between the changes. This is based on the fact that the above-mentioned signal having a large change almost changes the Base. Then, the first control data generation unit 202
When it is determined that the difference between the changes is smaller than a predetermined value, Gain, Bas corresponding to the input video signal are obtained using MAX, MIN and APL after passing through the LPF.
e is obtained and output. On the other hand, the first control data generation unit 2
In No. 02, when it is determined that the difference between the changes is larger than a predetermined value, Gain and Base corresponding to the input video signal are obtained and output using MAX and MIN that do not pass through the LPF.

By this processing, it is possible to perform an adjustment faithfully corresponding to the input video signal, and to make the change of the input video signal more prominent. The predetermined value can be set arbitrarily in accordance with the level of the input signal. In the first control data generation unit 202, whether or not the signal has a large change is determined only by the change of Base. However, it is also possible to determine by using the change of MAX or MIN. Further, if the first control data generation unit 202 determines that the difference between the changes is larger than a predetermined value, the first control data generation unit 202 appropriately changes the LPF characteristic and changes the LPF after the change.
By using MAX and MIN after passing through F, Gain and Base corresponding to the input video signal may be obtained and output.

As described above, according to the image display apparatus and the method according to the twentieth embodiment of the present invention, the light source luminance is adjusted while having a correlation with the signal amplitude control, and the output video signal with respect to the input video signal is output. In absorbing the APL fluctuation of the signal, the type and mode of the input video signal are determined to determine appropriate adjustment. This makes it possible to appropriately improve the sense of visual contrast for various types and modes of input video signals.

In the twentieth embodiment,
The case where the configuration of the first control data generation unit 202 is used in the image display device according to the fifteenth embodiment has been described. The same effect can be obtained even when used. Further, the first control data generation unit 202 in the twentieth embodiment is not necessarily limited to the above (1) to (1).
The configuration does not have to correspond to all of (3), and may be a configuration corresponding to only one or two.

(Twenty-first Embodiment) Generally, an input video signal is preliminarily subjected to a gamma correction process in order to correct a gamma characteristic of a CRT, assuming that a CRT is used as a display device. On the other hand, the light receiving type light modulation unit 157 (for example, a liquid crystal panel), which is a display device used in the present invention, does not have a gamma characteristic like a CRT. On the other hand, if only the contrast adjustment and the light source luminance adjustment as described in the fifteenth to twentieth embodiments are performed and output as it is, an appropriate image display may not be obtained. Therefore, in a twenty-first embodiment of the present invention, an input video signal that has been subjected to gamma correction processing in advance is subjected to inverse gamma correction processing to perform appropriate contrast adjustment and light source luminance adjustment.

FIG. 30 is a block diagram showing the structure of the image display device according to the twenty-first embodiment of the present invention. FIG.
In the image display device according to the twenty-first embodiment, the feature detection unit 151, the first control data generation unit 152,
Signal amplitude adjustment unit 153 and inverse gamma correction processing unit 211
, A feature data generator 154, a second control data generator 215, a light source controller 156, and a light receiving type light modulator 15.
7 is provided. In addition, the light receiving type light modulation unit 157 includes the light source 1.
58.

As shown in FIG. 30, in the image display device according to the twenty-first embodiment, the second control data generator 155 of the image display device according to the fifteenth embodiment is replaced with the second control data generator. 215, instead of the gamma inverse correction processing unit 211
Is further added. Note that the other configuration of the image display device according to the twenty-first embodiment is the same as the configuration of the image display device according to the fifteenth embodiment, and the configuration is denoted by the same reference numeral and described. Omitted. Hereinafter, the image display device according to the twenty-first embodiment of the present invention will be described mainly with reference to FIG. 31, focusing on components different from the image display device according to the fifteenth embodiment. FIG.
1 is a diagram illustrating an example of an inverse gamma characteristic in the inverse gamma correction processing unit 211 and the second control data generation unit 215 in FIG.

The gamma inverse correction processing section 211 receives the non-linear output video signal output from the signal amplitude adjustment section 153 and subjected to the gamma correction processing in advance, and according to the predetermined inverse gamma characteristic shown in FIG. Performs an inverse gamma correction process on the output video signal. The inverse gamma characteristic has a characteristic completely opposite (that is, cancels out the gamma characteristic) to the gamma characteristic applied to the input video signal in advance. For example, N
In the TSC standard, gamma = 2.2. As a result, a linear output video signal is output from the inverse gamma correction processing unit 211 to the light receiving type light modulation unit 157.

The second control data generation unit 215 includes the APL output from the feature detection unit 151 and the feature data generation unit 154.
And the APL2 output from. Then, the second control data generator 215 obtains a DC level difference β that has been subjected to gamma inverse correction processing from the difference α between APL and APL2 according to the predetermined inverse gamma characteristic shown in FIG. Output to the control unit 156. Note that the inverse gamma characteristic in the second control data generation unit 215 is based on the gamma inverse correction processing unit 2
11 is the same as the inverse gamma characteristic.

As described above, according to the image display apparatus and the method according to the twenty-first embodiment of the present invention, the light source luminance is adjusted with a correlation with the signal amplitude control, and the output video with respect to the input video signal is adjusted. In absorbing the APL fluctuation of the signal, the input video signal is subjected to an inverse gamma correction process for canceling a gamma correction process performed in advance, and appropriate contrast adjustment and light source luminance adjustment are performed. This makes it possible to appropriately improve the sense of visual contrast even for an input video signal that has been subjected to gamma correction processing in advance.

Note that in the twenty-first embodiment,
The case where the configurations of the inverse gamma correction processing unit 211 and the second control data generation unit 215 are used in the image display device according to the fifteenth embodiment has been described.
The same effects can be obtained even when used in the image display devices according to the sixth to twentieth embodiments.

(Twenty-second Embodiment) In the twenty-first embodiment, the case where the gamma inverse correction process is performed after the contrast adjustment and the light source luminance adjustment are performed has been described. Next, in a twenty-second embodiment of the present invention, after performing an inverse gamma correction process on an input video signal which has been subjected to a gamma correction process in advance, appropriate contrast adjustment and light source luminance adjustment are performed. Things.

FIG. 32 is a block diagram showing the structure of an image display device according to the twenty-second embodiment of the present invention. FIG.
In the image display device according to the twenty-second embodiment, the gamma inverse correction processing unit 221, the feature detection unit 151,
Control data generator 152 and signal amplitude adjuster 153
, A characteristic data generator 154, a second control data generator 155, a light source controller 156, and a light receiving type light modulator 15.
7 is provided. In addition, the light receiving type light modulation unit 157 includes the light source 1.
58.

As shown in FIG. 32, the image display device according to the twenty-second embodiment has a configuration in which a gamma inverse correction processing section 221 is further added to the image display device according to the fifteenth embodiment. Note that the other configuration of the image display device according to the twenty-second embodiment is the same as the configuration of the image display device according to the fifteenth embodiment. Omitted. Hereinafter, the image display device according to the twenty-second embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

The inverse gamma correction processing section 221 inputs a non-linear input video signal that has been subjected to gamma correction processing in advance, and performs input gamma correction on the input video signal according to a predetermined inverse gamma characteristic (see FIG. 31A). To perform gamma reverse correction processing. The inverse gamma characteristic has a characteristic completely opposite to the gamma characteristic previously applied to the input video signal (that is, cancels out the gamma characteristic), as in the twenty-first embodiment. As a result, the linear input video signal from the inverse gamma correction processing unit 221 is transmitted to the feature detection unit 151 and the signal amplitude adjustment unit 15.
3 is output.

As described above, according to the image display apparatus and the method according to the twenty-second embodiment of the present invention, the light source luminance is adjusted with the correlation with the signal amplitude control, and the output image for the input image signal is adjusted. In absorbing the APL fluctuation of the signal, the gamma correction process that cancels the gamma correction process performed in advance on the input video signal is performed to perform appropriate contrast adjustment and light source luminance adjustment. This makes it possible to appropriately improve the sense of visual contrast even for an input video signal that has been subjected to gamma correction processing in advance. Further, since the inverse gamma correction processing is performed at the stage of inputting the signal, it is not necessary to perform the inverse gamma correction processing in the second control data generator 155 as in the twenty-first embodiment.

In the twenty-second embodiment,
Although the case where the configuration of the gamma inverse correction processing unit 221 is used in the image display device according to the fifteenth embodiment has been described, the configuration is used in the image display devices according to the sixteenth to twentieth embodiments. Can achieve the same effect.

(Twenty-third Embodiment) As a display device applicable to the light-receiving type light modulation section 157 of the present invention, a panel using liquid crystal is conceivable. However, this liquid crystal panel has a characteristic that it responds quickly when the luminance change (APL change) of the video signal is large, and responds slowly when it is small. For this reason, if constant control is performed for all luminance changes, there may be cases where it is not possible to perform appropriate light source luminance adjustment suitable for an image. Therefore, in a twenty-third embodiment of the present invention, appropriate light source luminance adjustment suitable for a video is performed according to a luminance change of a video signal, that is, a response speed of a liquid crystal panel.

FIG. 33 is a block diagram showing the structure of an image display device according to the twenty-third embodiment of the present invention. FIG.
In the image display device according to the twenty-third embodiment, the feature detection unit 151, the first control data generation unit 152,
A signal amplitude adjustment unit 153, a feature data generation unit 154,
Second control data generation unit 155 and control data correction unit 2
31, a light source control unit 156, and a light receiving type light modulation unit (liquid crystal panel) 157. Also, the light receiving type light modulation section 157
Includes a light source 158.

As shown in FIG. 33, the image display device according to the twenty-third embodiment has a configuration in which a control data correction unit 231 is further added to the image display device according to the fifteenth embodiment. Note that the other configuration of the image display device according to the twenty-third embodiment is the same as the configuration of the image display device according to the fifteenth embodiment. Omitted. Hereinafter, an image display device according to a twenty-third embodiment of the present invention will be described mainly with reference to FIG. 34, focusing on components different from the image display device according to the fifteenth embodiment. FIG. 34 is a timing chart illustrating an example of a correction process performed by the control data correction unit 231 of FIG.

First, with reference to FIG. 34, the light source luminance adjustment in the image display devices according to the fifteenth to twenty-second embodiments will be described. When the APL change of the video signal is small (the signal A in FIG. 34A), the APL change of the actual video in the light receiving type optical modulator 157 becomes slow (the signal B in FIG. 34A takes three fields). Change). When the APL change of the video signal is large (signal A in FIG. 34B), the AP of the actual video in the light receiving type optical modulator 157 is used.
The change in L becomes faster (in the case of the signal B in FIG. 34B, the change is completed in one field). On the other hand, the light source 158
Is the DC level difference (signal C in FIGS. 34A and 34B) output from the second control data generator 155.
Changes in a predetermined period regardless of the APL change (signal D in FIGS. 34 (a) and (b)). For this reason, the AP of the video signal in the light receiving type light modulator 157 is
The L change does not match the brightness adjustment change of the light source 158 (in FIGS. 34A and 34B, the signal B and the signal D do not match).

Therefore, the control data correction unit 231 performs the following processing. The control data correction unit 231 is provided in advance with a filter (for example, an LPF) having a time constant corresponding to the response speed in the light receiving type optical modulation unit 157. The control data correction unit 231 receives the DC level difference output from the second control data generation unit 155 and detects the DC level difference. When the DC level difference is large, the control data correction unit 231 shortens the time constant of the filter, and when the DC level difference is small, increases the time constant of the filter.
The signal passes through the level difference and is output to the light source control unit 156 (signal E in FIGS. 34A and 34B). As a result, the change in the APL of the video signal in the light receiving type light modulation section 157 and the change in the brightness adjustment of the light source 158 match (FIG. 34).
In (a) and (b), the signal B and the signal F match).

As described above, according to the image display apparatus and the method according to the twenty-third embodiment of the present invention, the light source luminance is adjusted with a correlation with the signal amplitude control, and the output image for the input image signal is adjusted. In absorbing the APL fluctuation of the signal, appropriate light source luminance adjustment is performed in accordance with the response speed of the luminance change (APL change) of the video signal in the light receiving type light modulation unit 157. Accordingly, even when a liquid crystal panel or the like is used as the light receiving type light modulation section 157, it is possible to improve a sense of contrast suitable for a video signal.

In the twenty-third embodiment,
Although the case where the configuration of the control data correction unit 231 is used in the image display device according to the fifteenth embodiment has been described, the configuration may be used in the image display devices according to the sixteenth to twenty-second embodiments. Similar effects can be obtained.

(24th Embodiment) The 15th to 23rd embodiments
In the embodiment, the case where the contrast adjustment and the light source luminance adjustment are performed for the system displaying one screen has been described. However, the contrast adjustment and the light source luminance adjustment of the present invention can be similarly applied to a system that displays two screens on one light receiving type light modulation unit such as a personal computer (PC). is there. Therefore, in the twenty-fourth embodiment of the present invention, when the contrast adjustment and the light source luminance adjustment are used in a system that displays two screens, the sense of contrast is improved.

FIG. 35 is a block diagram showing the structure of the image display device according to the twenty-fourth embodiment of the present invention. FIG.
In the image display device according to the twenty-fourth embodiment, the feature detection unit 151, the first control data generation unit 152,
A first signal amplitude adjustment unit 153 and a feature data generation unit 15
4, the second control data generator 155, and the light source controller 1
56, a correction data generation unit 241, a second signal amplitude adjustment unit 242, a MIX 243, and a light receiving type optical modulation unit 157.
And In addition, the light receiving type light modulation unit 157 includes the light source 15.
8 is provided.

As shown in FIG. 35, the image display device according to the twenty-fourth embodiment is different from the image display device according to the fifteenth embodiment in that a correction data generation part 241 and a second signal amplitude adjustment part 242 are provided. MIX 243 is further added. Note that the other configuration of the image display device according to the twenty-fourth embodiment is the same as the configuration of the image display device according to the fifteenth embodiment, and the same configuration is denoted by the same reference numeral and described. Omitted. The first signal amplitude adjustment unit 153 of the image display device according to the twenty-fourth embodiment has the same configuration as the signal amplitude adjustment unit 153 of the image display device according to the fifteenth embodiment. Reference numbers are assigned. Hereinafter, with further reference to FIGS. 17 and 36, an image display device according to a twenty-fourth embodiment of the present invention will be described.
The following description focuses on components that are different from the image display device according to the fifteenth embodiment. FIG. 36 is a diagram illustrating an example of an outline of a process performed by an image display device according to a twenty-fourth embodiment of the present invention on a certain input video signal.

Now, consider a case in which when two screens (windows) as shown in FIG. 17 are displayed on the light receiving type light modulation section 157, contrast adjustment and light source luminance adjustment are performed on the first screen. . In this case, a video signal processing circuit (not shown) such as a television receiver or a computer device converts the first input video signal, which is a video signal corresponding to the first screen (control target screen), into the feature detection unit 151. The second input video signal, which is a video signal corresponding to the second screen (screen not to be controlled), is output to the second signal amplitude adjustment section 242 to the first signal amplitude adjustment section 153. In addition, the video signal processing circuit outputs a window switching signal for giving which screen is an output video signal to the MIX.
243.

First, the feature detector 151, the first control data generator 152, the first signal amplitude adjuster 153, the feature data generator 154, the second control data generator 155, and the light source controller 156 For one input video signal,
The contrast adjustment and the light source luminance adjustment are performed by performing the processing described in the fifteenth embodiment (FIG. 36A).

The correction data generator 241 receives the DC level difference output from the second control data generator 155.
Then, based on the DC level difference, the correction data generation unit 241 prevents the influence of the light source luminance adjustment performed on the first input video signal from affecting the second input video signal (ie, And a signal for correcting the amplitude of the second input video signal (so that the light source luminance adjustment effect is canceled). The second signal amplitude adjustment unit 242 receives the correction signal output from the correction data generation unit 241 and the second input video signal, and amplifies or attenuates the amplitude of the second input video signal according to the correction signal. Here, the second signal amplitude adjustment unit 242 amplifies or attenuates the second input video signal based on the black level (FIG. 36B). MIX 243
The first input video signal after the contrast adjustment output from the first signal amplitude adjustment unit 153 and the second signal amplitude adjustment unit 2
A second input video signal after the contrast correction output by 42 is input, and the output video signal to be output to the light receiving type light modulator 157 is switched according to the timing given by the window switching signal.

By this processing, the amplitude of the second input video signal can be corrected so as to always cancel the luminance adjustment of the light source 158 performed on the first input video signal (FIG. 36 (b) )), The influence of the contrast adjustment and the light source luminance adjustment performed on the first screen does not affect the second screen.

As described above, according to the image display apparatus and the method according to the twenty-fourth embodiment of the present invention, in the system for displaying two screens, the contrast adjustment and the light source luminance adjustment are performed on the control target screen. The correction is performed on the non-control target screen so as to cancel the light source luminance adjustment effect. As a result, even in a system that performs two-screen display, it is possible to appropriately improve the sense of visual contrast without discomfort in both screens.

[0210] In the twenty-fourth embodiment,
Correction data generator 241, second signal amplitude adjuster 242
And the case where the configuration of MIX 243 is used in the image display device according to the fifteenth embodiment, the same effect can be obtained by using the configuration in the image display device according to the sixteenth to twenty-third embodiments. It is possible to play. Also,
In the twenty-fourth embodiment, the reference at which the second signal amplitude adjustment unit 242 amplifies or attenuates the second input video signal is the black level. However, the criterion is not limited to the black level, and the APL level or an arbitrary level is set as a criterion by performing feature detection (similar to the feature detection unit 151) on the second input video signal. It is possible to

(Twenty-fifth Embodiment) In the twenty-fourth embodiment, the contrast adjustment and the light source luminance adjustment described in the fifteenth to twenty-third embodiments are performed by setting two screens on one light receiving type light modulation section. The case of using the display system has been described. Therefore, a description will now be given of a case where the contrast adjustment and the light source luminance adjustment according to the present invention are applied to a system that displays three or more screens so as to improve the sense of contrast. In the following twenty-fifth embodiment, the contrast adjustment and the light source luminance adjustment of the present invention are performed as follows.
A case where the present invention is used in a system that displays three screens will be described as an example.

FIG. 37 is a block diagram showing the structure of the image display device according to the twenty-fifth embodiment of the present invention. FIG.
In the image display device according to the twenty-fifth embodiment, the first feature detection unit 151 and the first control data generation unit 15
2, a first signal amplitude adjuster 153, a feature data generator 154, a second control data generator 155, a light source controller 156, a second feature detector 251 and a third control data. A generating unit 252 and a second signal amplitude adjusting unit 153
, A correction data generation unit 254, a third signal amplitude adjustment unit 255, a MIX 253, and a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 37, the image display device according to the twenty-fifth embodiment is different from the image display device according to the fifteenth embodiment in that a second feature detector 251 and a third control data generator are provided. 252, the second signal amplitude adjustment unit 153, the correction data generation unit 254, the third signal amplitude adjustment unit 255, and the MI
X253 is further added. Note that the other configuration of the image display device according to the twenty-fifth embodiment is the same as the configuration of the image display device according to the fifteenth embodiment. Omitted. Further, the first feature detection unit 151 and the first signal amplitude adjustment unit 15 of the image display device according to the twenty-fifth embodiment.
3 has the same reference numerals as the feature detector 151 and the signal amplitude adjuster 153 of the image display device according to the fifteenth embodiment, respectively. Further, the second signal amplitude adjustment unit 153 also performs
Signal amplitude adjuster 15 of image display device according to fifth embodiment
3 has the same reference numerals. Hereinafter, an image display device according to the twenty-fifth embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

Now, consider a case in which, when three screens (first to third screens) are displayed on the light receiving type light modulator 157, contrast adjustment and light source luminance adjustment are performed on the first screen. . In this case, a video signal processing circuit (not shown) such as a television receiver or a computer device converts a first input video signal, which is a video signal corresponding to a first screen (a control target screen), into a first characteristic. The detection unit 151 and the first signal amplitude adjustment unit 153 provide a second screen (a screen not to be controlled).
The second input video signal, which is a video signal corresponding to the second input signal, is supplied to the second feature detection unit 251 and the second signal amplitude adjustment unit 153.
The third input video signal, which is a video signal corresponding to the third screen (screen not to be controlled), is supplied to the third signal amplitude adjustment unit 25.
5 respectively. Further, the video signal processing circuit outputs a window switching signal to the MIX 253 which indicates which screen is an output video signal.

First, a first feature detector 151, a first control data generator 152, a first signal amplitude adjuster 153,
Feature data generator 154, second control data generator 15
5 and the light source control unit 156 perform the processing described in the fifteenth embodiment on the first input video signal to perform contrast adjustment and light source luminance adjustment.

Next, like the first feature detecting section 151, the second feature detecting section 251 outputs the MA of the second input video signal.
X, MIN and APL are detected respectively. The third control data generation unit 252 inputs MAX and MIN detected by the second feature detection unit 251 and the DC level difference output by the second control data generation unit 155. And
The third control data generation unit 252 cancels the influence of the brightness control of the light source by the light source control unit 156, and sets the maximum amplitude of the second input video signal to the output dynamic range of the second signal amplitude adjustment unit 153. Gain for amplifying to a predetermined level within the range is obtained. Further, the third control data generation unit 252 determines MAX and MIN and the Ga
From “in”, Base, which is the only level whose level does not fluctuate in the input video signal after amplification, for keeping the input video signal after amplification performed by the second signal amplitude adjustment unit 153 within the output dynamic range, is obtained. This found Gai
n and Base are output to the second signal amplitude adjustment unit 153. In the second signal amplitude adjustment unit 153, the first signal
Processing similar to that of the input signal processing unit 13 described in the fifth embodiment is performed.

The correction data generator 254 receives the DC level difference output from the second control data generator 155.
Then, based on the DC level difference, the correction data generation unit 254 prevents the influence of the light source luminance adjustment performed on the first input video signal from affecting the third input video signal (that is, the third input video signal). And a signal for correcting the amplitude of the third input video signal (so that the light source luminance adjustment effect is canceled). The third signal amplitude adjustment unit 255 receives the correction signal output from the correction data generation unit 254 and the third input video signal, and amplifies or attenuates the amplitude of the third input video signal according to the correction signal. Here, the third signal amplitude adjustment unit 255 amplifies or attenuates the third input video signal based on the black level. The MIX 253 includes a first input video signal after the contrast adjustment output by the first signal amplitude adjustment unit 153, a second input video signal after the contrast correction output by the second signal amplitude adjustment unit 153, 3 and the third input video signal after the contrast correction output by the signal amplitude adjustment unit 255 of the third type is input, and the light receiving type light modulation unit 15 is provided in accordance with the timing given by the window switching signal.
The output video signal to be output to 7 is switched.

By this processing, the amplitudes of the second and third input video signals can be corrected so as to always cancel the luminance adjustment of the light source 158 performed on the first input video signal, and A unique contrast adjustment can be performed on the second input video signal. As a result, the effects of the contrast adjustment and the light source luminance adjustment performed on the first screen are not affected on the second and third screens, and the unique contrast adjustment is performed on the second screen. It can be performed.

As described above, according to the image display apparatus and method according to the twenty-fifth embodiment of the present invention, in a system for displaying three or more screens, the contrast adjustment and the light source luminance adjustment are performed for the control target screen. And make corrections to cancel the light source brightness adjustment effect for screens not to be controlled. Do. As a result, even in a system for displaying three or more screens, it is possible to appropriately improve the sense of visual contrast without discomfort on all screens.

[0220] In the twenty-fifth embodiment,
Second feature detection unit 251, third control data generation unit 25
2, the second signal amplitude adjustment unit 153, the correction data generation unit 2
54, the third signal amplitude adjusting unit 255 and the MIX 253
The configuration described above is used in the image display device according to the fifteenth embodiment.
The same effect can be obtained even when used in the image display device according to the third embodiment. In the twenty-fifth embodiment, the case where the contrast adjustment and the light source luminance adjustment of the present invention are used in a system that displays three screens has been described as an example. However, three or more screens are displayed. Similar effects can be obtained even when used in a system. In this case, when there are a plurality of screens for which unique contrast adjustment needs to be performed, the second feature detection unit 251 and the third
A plurality of configurations equivalent to those of the control data generation unit 252 and the second signal amplitude adjustment unit 153 may be used.

(Twenty-Sixth Embodiment) The fifteenth to twenty-fifth embodiments
In the embodiment, the first control data generators 152 and 17
Based on Gain and Base obtained in 2,202,
The case in which APL2 is generated in feature data generating section 154 has been described. Next, in the twenty-sixth embodiment, the A based on the output video signal output from the signal amplitude adjustment unit 153.
PL2 is generated.

FIG. 38 is a block diagram showing the structure of an image display device according to the twenty-sixth embodiment of the present invention. FIG.
In the image display device according to the twenty-sixth embodiment, the feature display unit 151, the first control data generation unit 152,
Signal amplitude adjusting section 153 and output signal characteristic detecting section 264
, A second control data generator 155, and a light source controller 15
6 and a light receiving type light modulator 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 38, in the image display device according to the twenty-sixth embodiment, the feature data generator 154 of the image display device according to the fifteenth embodiment is replaced with an output signal feature detector 264. Configuration. The components of the image display device according to the twenty-sixth embodiment are the same as the components of the image display device according to the fifteenth embodiment. Omitted. Hereinafter, an image display device according to a twenty-sixth embodiment of the present invention will be described.
The following description focuses on processing operations different from those of the image display device according to the fifteenth embodiment.

The output signal characteristic detecting section 264 receives the output video signal output from the signal amplitude adjusting section 153. Then, similarly to the feature detection unit 151, the output signal feature detection unit 264 detects the average luminance level (APL2) of the output video signal and outputs the same to the second control data generation unit 155.
The second control data generation unit 155 receives the APL output from the feature detection unit 151 and the APL2 output from the output signal feature detection unit 264. Then, the second control data generation unit 155 calculates the DC level difference (= APL) of the average luminance level.
2-APL) and outputs it to the light source control unit 156.

As described above, according to the image display apparatus and the method according to the twenty-sixth embodiment of the present invention, the brightness adjustment of the light source 158 is made to have a correlation with the signal amplitude control performed by the signal amplitude adjustment unit 153. To absorb the APL fluctuation of the output video signal with respect to the input video signal. Thereby, the light source 1
The visual contrast can be improved without increasing the average power consumption of 58.

In the twenty-sixth embodiment,
The case where the configuration of the output signal feature detection unit 264 is used in the image display device according to the fifteenth embodiment has been described. Can achieve the same effect.

(Twenty-seventh embodiment) The fifteenth to twenty-sixth embodiments
In the embodiment, the first control data generators 152 and 17
The case where the contrast adjustment and the light source luminance adjustment are performed based on the Base obtained in step 2, 202 has been described. Next, in the twenty-seventh embodiment, the contrast adjustment and the light source luminance adjustment are performed based on the minimum value of the system (the lower limit value of the output dynamic range in the signal amplitude adjustment unit 153).

FIG. 39 is a block diagram showing the structure of an image display device according to the twenty-seventh embodiment of the present invention. FIG.
In the image display device according to the twenty-seventh embodiment, the feature detection unit 151, the first control data generation unit 272,
A signal amplitude adjustment unit 273, a feature data generation unit 274,
Second control data generation unit 155 and light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 39, the image display device according to the twenty-seventh embodiment comprises a first control data generator 152, a signal amplitude adjuster 153, and a feature of the image display device according to the fifteenth embodiment. In this configuration, the data generation unit 154 is replaced with a first control data generation unit 272, a signal amplitude adjustment unit 273, and a feature data generation unit 274. The second
Other configurations of the image display device according to the seventh embodiment are the same as those of the image display device according to the fifteenth embodiment, and the same reference numerals are given to the same components, and description thereof will be omitted. Hereinafter, the image display device according to the twenty-seventh embodiment of the present invention will be described mainly with reference to FIG. FIG. 40 is a view for explaining an example of the outline of the processing performed by the image display device according to the twenty-seventh embodiment of the present invention on a certain input video signal.

The first control data generator 272 inputs MAX and MIN detected by the feature detector 151,
Gain based on IN is obtained as follows. now,
The feature detecting unit 151 detects the input video signal as shown in FIG.
Consider a case where MAX, MIN and APL are detected as shown in FIG.

The first control data generating section 272 determines the maximum amplitude (difference between MAX and MIN) of the input video signal by a signal processing range of the processing circuit, that is, a dynamic range (specifically, signal amplitude adjustment). Gain for amplifying up to the output dynamic range) width of the unit 273 is obtained according to the following equation. Gain = dynamic range width / (MAX-MIN) For example, in FIG. 40, when the maximum amplitude of the input video signal is 67% of the dynamic range width (FIG. 40)
(A)), Ga obtained by the first control data generator 272
in becomes about 1.5 times (FIG. 40 (b)).

The signal amplitude adjustment unit 273 receives the input video signal, the MIN detected by the feature detection unit 151, and the Gain output by the first control data generation unit 272. Then, first, the signal amplitude adjustment unit 273 subtracts the value of MIN from the input video signal to level-shift the minimum value of the signal to the lower limit of the output dynamic range (FIG. 40).
(C)). Next, the signal amplitude adjuster 273 amplifies the input video signal in accordance with the gain based on the lower limit value (FIG. 40 (d)). Thus, the input video signal is amplified to the full output dynamic range of the signal amplitude adjustment unit 273 and output. The input video signal (output video signal) after the amplification is output to the light receiving type light modulation section 157 and displayed as an image.

[0233] The feature data generation unit 274 is
The MIN and APL detected by 51 and the Gain obtained by the first control data generator 272 are input. Then, the characteristic data generation unit 274 calculates an average luminance level (APL2) in the output video signal based on MIN, APL, and Gain according to the following equation. APL2 = (APL−MIN) × Gain This APL2 is output to the second control data generator 155.

As described above, according to the image display apparatus and the method according to the twenty-seventh embodiment of the present invention, the brightness adjustment of the light source 158 is performed while having a correlation with the signal amplitude control performed by the signal amplitude adjustment unit 273. To absorb the APL fluctuation of the output video signal with respect to the input video signal. Thereby, the light source 1
The visual contrast can be improved without increasing the average power consumption of 58.

In the twenty-seventh embodiment,
First control data generator 272, signal amplitude adjuster 273
The case where the configuration of the feature data generation unit 274 is used in the image display device according to the fifteenth embodiment has been described. Can achieve the same effect.

(Twenty-eighth Embodiment) In the twenty-seventh embodiment, the minimum value of the system (the lower limit value of the output dynamic range in the signal amplitude adjustment unit 153) is used as a reference.
The case where the contrast adjustment and the light source luminance adjustment are performed has been described. Next, a twenty-eighth embodiment will be described in which contrast adjustment and light source luminance adjustment are performed based on the maximum value of the system (the upper limit value of the output dynamic range in the signal amplitude adjustment unit 153).

FIG. 41 is a block diagram showing the structure of an image display device according to the twenty-eighth embodiment of the present invention. FIG.
In the image display device according to the twenty-eighth embodiment, the feature detection unit 151, the first control data generation unit 282,
A signal amplitude adjustment unit 283, a feature data generation unit 284,
Second control data generation unit 155 and light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 41, the image display device according to the twenty-eighth embodiment comprises a first control data generator 152, a signal amplitude adjuster 153 and a feature of the image display device according to the fifteenth embodiment. In this configuration, the data generation unit 154 is replaced with a first control data generation unit 282, a signal amplitude adjustment unit 283, and a feature data generation unit 284. The second
Other configurations of the image display device according to the eighth embodiment are the same as the configurations of the image display device according to the fifteenth embodiment, and the same reference numerals are given to the same components and description thereof will be omitted. Hereinafter, an image display device according to a twenty-eighth embodiment of the present invention will be described mainly with reference to FIG. 42, focusing on components different from the image display device according to the fifteenth embodiment. FIG. 42 is a view for explaining an example of the outline of the processing performed on an input video signal by the image display device according to the twenty-eighth embodiment of the present invention.

The first control data generator 282 inputs MAX and MIN detected by the feature detector 151,
Gain based on AX is obtained as follows. now,
The feature detection unit 151 performs the processing shown in FIG.
Consider a case where MAX, MIN and APL are detected as shown in FIG.

The first control data generating section 282 determines the maximum amplitude (difference between MAX and MIN) of the input video signal by the signal processing range of the processing circuit, that is, the dynamic range (specifically, the signal amplitude adjustment). Gain for amplifying up to the output dynamic range) width of the section 283 is obtained according to the following equation. Gain = dynamic range width / (MAX-MIN) For example, in FIG. 42, when the maximum amplitude of the input video signal is 67% of the dynamic range width (FIG. 42).
(A)), Ga obtained by the first control data generation unit 282
in becomes about 1.5 times (FIG. 42 (b)).

The signal amplitude adjusting section 283 receives the input video signal, the MAX detected by the feature detecting section 151, and the Gain output from the first control data generating section 282. First, the signal amplitude adjusting unit 283 calculates a difference value between the upper limit value of the output dynamic range and MAX, adds the difference value to the input video signal, and increases the maximum value of the signal to the upper limit value of the output dynamic range. Level shift (FIG. 42)
(C)). Next, the signal amplitude adjuster 283 amplifies the input video signal in accordance with the gain with reference to the upper limit value (FIG. 42 (d)). Thus, the input video signal is amplified to the full output dynamic range of the signal amplitude adjustment unit 283 and output. The input video signal (output video signal) after the amplification is output to the light receiving type light modulation section 157 and displayed as an image.

[0242] The feature data generation unit 284
MAX and APL detected by 51 and Gain obtained by the first control data generator 282 are input. Then, based on MAX, APL, and Gain, the feature data generation unit 284 calculates an average luminance level (APL2) in the output video signal according to the following equation. APL2 = (APL + difference value [upper limit value-MAX]) × G
ain This APL2 is output to the second control data generation unit 155.

As described above, according to the image display apparatus and the method according to the twenty-eighth embodiment of the present invention, the brightness adjustment of the light source 158 is performed while having a correlation with the signal amplitude control performed by the signal amplitude adjustment unit 283. To absorb the APL fluctuation of the output video signal with respect to the input video signal. Thereby, the light source 1
The visual contrast can be improved without increasing the average power consumption of 58.

In the twenty-eighth embodiment,
First control data generator 282, signal amplitude adjuster 283
The case has been described in which the configuration of the feature data generation unit 284 is used in the image display device according to the fifteenth embodiment, but the configuration is used in the image display devices according to the sixteenth to twenty-sixth embodiments. Can achieve the same effect.

(Twenty-Ninth Embodiment) In the first to fourteenth embodiments, the APL is detected by the feature detection units 11 and 61, and the contrast adjustment and the light source luminance adjustment are performed using the APL. Therefore, the feature detection unit 1
There is still a problem that the configuration of the devices 1 and 61 becomes complicated. Thus, in the twenty-ninth embodiment, contrast adjustment and light source luminance adjustment are performed without using APL.

FIG. 43 is a block diagram showing the structure of the image display apparatus according to the twenty-ninth embodiment of the present invention. FIG.
In the image display device according to the twenty-ninth embodiment, the feature detection unit 291, the first control data generation unit 292,
The input signal processing unit 293 and the second control data generation unit 29
5, a light source controller 16 and a light receiving type light modulator 17. Further, the input signal processing unit 293 includes the signal amplitude adjustment unit 2
93A and a DC level adjustment unit 293B. The light receiving type light modulator 17 includes a light source 18.

As shown in FIG. 43, the image display device according to the twenty-ninth embodiment comprises the feature detector 11, control data generator 12, and input signal processor 13 of the image display device according to the first embodiment. Is replaced by a feature detection unit 291, a first control data generation unit 292, and an input signal processing unit 293, and a second control data generation unit 295 is further added. Note that the other configuration of the image display device according to the twenty-ninth embodiment is the same as the configuration of the image display device according to the first embodiment, and the configuration is denoted by the same reference numeral and described. Omitted. Hereinafter, an image display device according to the twenty-ninth embodiment of the present invention will be described, focusing on components different from those of the image display device according to the first embodiment.

First, a video signal output from a video signal processing circuit (not shown) such as a television receiver or a computer device is input as an input video signal to the feature detection section 291 and the input signal processing section 293, respectively. . The feature detecting unit 291 detects MAX and MIN of the input video signal, respectively.

The first control data generator 292 inputs MAX and MIN detected by the feature detector 291,
ain and Offset are obtained as follows. First,
The first control data generation unit 292 converts the maximum amplitude (the difference between MAX and MIN) of the input video signal into a signal processable range of the processing circuit, that is, a dynamic range (specifically, a DC level adjustment unit 293B). Gain for amplifying to the output dynamic range) width is obtained according to the following equation. Gain = dynamic range / (MAX-MIN) The obtained Gain is output to the signal amplitude adjustment unit 293A.

Next, the first control data generator 292
From MAX and MIN, and the above calculated Gain, the average value of MAX and MIN of the input video signal [= (MAX-MI
N) / 2], and an Offset that gives a DC level within which the input video signal amplified by the signal amplitude adjustment unit 293A based on the average value falls within the output dynamic range. This is to change the DC level of the amplified video signal so that the amplitude of the amplified video signal falls within the dynamic range. The obtained Offset is supplied to the DC level adjustment unit 293B and the second control data generation unit 29.
5 is output.

The signal amplitude adjustment section 293A receives the input video signal, MAX and MIN output from the feature detection section 291 and Gain output from the first control data generation section 292. Then, the signal amplitude adjustment unit 293A amplifies the input video signal in accordance with the gain based on the average value. This amplified video signal is output to DC level adjustment section 293B.

The DC level adjuster 293B receives the amplified video signal output from the signal amplitude adjuster 293A and the Offset output from the first control data generator 292.
Then, the DC level adjustment unit 293B shifts the DC level of the amplified video signal according to the Offset. The amplified video signal (output video signal) after the level shift is output to the light receiving type light modulation unit 17 and displayed as an image.

On the other hand, the second control data generator 295
MAX and MIN output by the feature detection unit 291 and the first
Of the control data generation unit 292 is input. Then, the second control data generation unit 295
Based on MAX and MIN, and Offset, a DC level difference between the average value and Offset is obtained and output to light source control unit 16.

Then, the light source control unit 16 controls the visual luminance level of the output video signal to be equal to the luminance level of the input video signal according to the DC level difference output from the second control data generation unit 295, that is, The luminance of the light source 18 is predetermined so that the average value of the output video signal is the same as the average value of the input video signal.

As described above, according to the image display apparatus and method of the twenty-ninth embodiment of the present invention, the signal amplitude control performed by the input signal processing unit 293 (the signal amplitude adjustment unit 293A and the DC level adjustment unit 293B) is performed. The brightness of the light source 18 is adjusted so as to have a correlation with the above, and the APL fluctuation of the output video signal with respect to the input video signal is absorbed. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18. Further, the configuration of the feature detecting unit 291 can be simplified.

Incidentally, in the twenty-ninth embodiment,
Feature detector 291, first control data generator 292, input signal processor 293, and second control data generator 29
The case where the configuration 5 is used in the image display device according to the first embodiment has been described.
The same effect can be obtained even when used in the image display device according to the embodiment. In addition, the signal amplitude adjustment unit 293A and the DC level adjustment unit 293 in the input signal processing unit 293 in the image display device according to the twenty-ninth embodiment.
Even if the configuration order of B is changed to the configuration order described in the second embodiment, the same effect can be obtained as a matter of course.

(Thirtieth Embodiment) The fifteenth to twenty-fifth embodiments
In the embodiment, the feature detection units 151 and 191
Since the PL is detected and the light source luminance is adjusted using the APL, there is still a problem that the configuration of the feature detection units 151 and 191 becomes complicated. Therefore,
In the thirtieth embodiment, light source luminance adjustment is performed without using APL.

FIG. 44 is a block diagram showing the structure of the image display device according to the thirtieth embodiment of the present invention. FIG.
In the image display device according to the thirtieth embodiment, the feature detection unit 301, the first control data generation unit 152,
A signal amplitude adjustment unit 153, a feature data generation unit 304,
Second control data generation unit 305 and light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 44, the image display device according to the thirtieth embodiment comprises a feature detector 151 and a feature data generator 154 of the image display device according to the fifteenth embodiment.
And the second control data generation unit 155
01, a configuration in which the feature data generation unit 304 and the second control data generation unit 305 are replaced. The other configuration of the image display device according to the thirtieth embodiment is the same as that of the fifteenth embodiment.
The configuration is the same as that of the image display device according to the embodiment, and the configuration is denoted by the same reference numeral and description thereof is omitted. Hereinafter, the image display device according to the thirtieth embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

First, a video signal output from a video signal processing circuit (not shown) such as a television receiver or a computer device is used as an input video signal as a feature detector 301 and a signal amplitude adjuster as an input signal processor. 153 are respectively input. The feature detection unit 301 calculates the M of the input video signal.
AX and MIN are detected respectively.

The feature data generation unit 304 is the feature detection unit 3
01, the MAX and MIN detected, and the Gain and Base obtained by the first control data generator 152 are input. Then, the feature data generation unit 304 determines MAX,
Average value of MAX and MIN of the input video signal based on MIN, Gain, and Base [= (MAX−MIN)
/ 2] calculates a value (hereinafter referred to as AVE) to be moved by the contrast adjustment in the signal amplitude adjustment unit 153.
This AVE is output to the second control data generation unit 305.

The second control data generator 305 receives MAX and MIN output from the feature detector 301 and AVE output from the feature data generator 304. And
The second control data generation unit 305 includes the MAX and MIN
And the AVE, the DC level difference between the average value and the AVE is obtained and output to the light source control unit 156.

Then, the light source control unit 156 calculates the DC level difference according to the DC level difference output from the second control data generation unit 305.
The visual luminance level of the output video signal is equal to the luminance level of the input video signal, that is, the obtained A
A predetermined brightness adjustment is performed on the light source 158 so that VE becomes the same as the average value in the input video signal.

As described above, according to the image display apparatus and the method according to the thirtieth embodiment of the present invention, the brightness adjustment of the light source 158 is performed while having a correlation with the signal amplitude control performed by the signal amplitude adjustment unit 153. To absorb the APL fluctuation of the output video signal with respect to the input video signal. Thereby, the light source 1
The visual contrast can be improved without increasing the average power consumption of 58. Also, the feature detection unit 3
01 can be simplified.

Note that in the thirtieth embodiment,
The feature detector 301, the feature data generator 304, and the second
The case where the configuration of the control data generation unit 305 is used in the image display device according to the fifteenth embodiment has been described, but the configuration is used in the image display devices according to the sixteenth to twenty-fifth embodiments. Can achieve the same effect.

(Thirty-First Embodiment) In the twenty-ninth embodiment, in the image display device according to the first to fourteenth embodiments, the contrast adjustment and the average value of MAX and MIN of the input video signal are performed by using the average value. The case where the light source luminance adjustment is performed has been described. Next, in the thirty-first embodiment, the contrast adjustment and the light source luminance adjustment are performed using the luminance level having the highest number of appearances for each field, instead of the average value.

FIG. 45 is a block diagram showing the structure of the image display device according to the thirty-first embodiment of the present invention. FIG.
In the image display device according to the thirty-first embodiment, the feature detection unit 311, the first control data generation unit 312,
The input signal processing unit 313 and the second control data generation unit 31
5, a light source controller 16 and a light receiving type light modulator 17. Further, the input signal processing unit 313 includes the signal amplitude adjustment unit 3.
13A and a DC level adjustment unit 313B. The light receiving type light modulator 17 includes a light source 18.

As shown in FIG. 45, the image display device according to the thirty-first embodiment is the same as the feature display unit 11, control data generation unit 12, and input signal processing unit 13 of the image display device according to the first embodiment. Is replaced with a feature detection unit 311, a first control data generation unit 312, and an input signal processing unit 313, and a second control data generation unit 315 is further added. Note that the other configuration of the image display device according to the thirty-first embodiment is the same as the configuration of the image display device according to the first embodiment, and the configuration is denoted by the same reference numeral and described. Omitted. Hereinafter, the image display device according to the thirty-first embodiment of the present invention will be described focusing on components different from the image display device according to the first embodiment.

First, a video signal output from a video signal processing circuit (not shown) such as a television receiver or a computer device is input to the feature detection unit 311 and the input signal processing unit 313 as an input video signal. . The feature detection unit 311 outputs a luminance level (hereinafter, referred to as “MAX” and “MIN”) of the input video signal which is the highest in each field.
HIST) are detected.

The first control data generator 312 inputs MAX, MIN, and HIST detected by the feature detector 311 and obtains Gain and Offset as follows. First, the first control data generation unit 312 determines the maximum amplitude (difference between MAX and MIN) of the input video signal as a signal processable range of the processing circuit, that is, a dynamic range (specifically, a DC level adjustment unit). Gain for amplifying up to the output dynamic range of 313B) width is obtained according to the following equation. Gain = dynamic range / (MAX-MIN) The obtained gain is output to the signal amplitude adjustment unit 313A.

Next, the first control data generator 312
From MAX and MIN, and the above calculated Gain, an Offset that gives a DC level within which the input video signal amplified by the signal amplitude adjustment unit 313A based on the HIST standard falls within the output dynamic range is obtained. This is to change the DC level of the amplified video signal so that the amplitude of the amplified video signal falls within the dynamic range. The calculated Offset is output to DC level adjustment section 313B and second control data generation section 315.

The signal amplitude adjuster 313A receives the input video signal, the HIST output from the feature detector 311 and the Gain output from the first control data generator 312. Then, the signal amplitude adjustment unit 313A amplifies the input video signal in accordance with the gain based on the HIST. This amplified video signal is output to DC level adjustment section 313B.

The DC level adjuster 313B receives the amplified video signal output from the signal amplitude adjuster 313A and the Offset output from the first control data generator 312.
Then, the DC level adjuster 313B shifts the DC level of the amplified video signal according to the Offset. The amplified video signal (output video signal) after the level shift is output to the light receiving type light modulation unit 17 and displayed as an image.

On the other hand, the second control data generator 315
The HIST output from the feature detection unit 311 and the Offset output from the first control data generation unit 312 are input.
Then, the second control data generation unit 315 obtains a DC level difference between HIST and Offset based on HIST and Offset, and outputs the difference to the light source control unit 16.

The light source control unit 16 controls the visual luminance level of the output video signal to be equal to the luminance level of the input video signal according to the DC level difference output from the second control data generation unit 315, that is, The luminance of the light source 18 is predetermined so that the HIST of the output video signal is the same as the HIST of the input video signal.

As described above, according to the image display apparatus and method of the thirty-first embodiment of the present invention, the signal amplitude control performed by the input signal processing unit 313 (the signal amplitude adjustment unit 313A and the DC level adjustment unit 313B) The brightness of the light source 18 is adjusted with a correlation with the above, and the APL fluctuation of the output video signal with respect to the input video signal is absorbed. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18.

Note that in the thirty-first embodiment,
Feature detector 311, first control data generator 312, input signal processor 313, and second control data generator 31
The case where the configuration 5 is used in the image display device according to the first embodiment has been described.
The same effect can be obtained even when used in the image display device according to the embodiment. Further, the signal amplitude adjustment unit 313A and the DC level adjustment unit 313 in the input signal processing unit 313 in the image display device according to the thirty-first embodiment.
Even if the configuration order of B is changed to the configuration order described in the second embodiment, the same effect can be obtained as a matter of course.

(Thirty-second Embodiment) In the thirtieth embodiment, in the image display device according to the fifteenth to twenty-fifth embodiments, the contrast adjustment and the average value of the MAX and MIN of the input video signal are performed. The case where the light source luminance adjustment is performed has been described. Next, in the thirty-second embodiment, the contrast adjustment and the light source luminance adjustment are performed not by using the average value but by using the luminance level having the largest number of appearances for each field.

FIG. 46 is a block diagram showing the structure of the image display device according to the thirty-second embodiment of the present invention. FIG.
In the image display device according to the thirty-second embodiment, the feature detection unit 321, the first control data generation unit 152,
A signal amplitude adjustment unit 153, a feature data generation unit 324,
The second control data generation unit 325 and the light source control unit 156
And a light receiving type light modulation unit 157. In addition, the light receiving type light modulation section 157 includes a light source 158.

As shown in FIG. 46, the image display device according to the thirty-second embodiment is the same as the feature detection unit 151 and the feature data generation unit 154 of the image display device according to the fifteenth embodiment.
And the second control data generation unit 155
21, a configuration in which the feature data generator 324 and the second control data generator 325 are replaced. The other configuration of the image display device according to the thirty-second embodiment is the same as that of the fifteenth embodiment.
The configuration is the same as that of the image display device according to the embodiment, and the configuration is denoted by the same reference numeral and description thereof is omitted. Hereinafter, the image display device according to the thirty-second embodiment of the present invention will be described focusing on components different from the image display device according to the fifteenth embodiment.

First, a video signal output from a video signal processing circuit (not shown) such as a television receiver or a computer is used as an input video signal as a feature detector 321 and a signal amplitude adjuster as an input signal processor. 153 are respectively input. The feature detection unit 321 calculates the M of the input video signal.
A luminance level (HIST) having the highest number of appearances is detected for each of AX, MIN, and each field.

[0282] The feature data generation section 324
21 and the first control data generator 1
52 inputs the obtained Gain and Base. Then, the feature data generation unit 324 outputs the HIST, Gain
HI in the input video signal based on
The ST calculates a value (hereinafter, referred to as HIST2) to be moved by the contrast adjustment in the signal amplitude adjustment unit 153. This HIST2 is provided by the second control data generation unit 325.
Output to

[0283] The second control data generation unit 325 includes the HIST output from the feature detection unit 321 and the feature data generation unit 3
24 and the HIST2 output. And the second
The control data generation unit 325 of FIG. 2 generates a DC level difference (= HIST2-HIST) based on HIST and HIST2.
And outputs it to the light source control unit 156.

Then, the light source control unit 156 determines the DC level difference output from the second control data generation unit 325 according to the DC level difference.
The visual luminance level of the output video signal is equal to the luminance level of the input video signal, that is, the HIST (= HIST2) of the output video signal is H
A predetermined luminance adjustment is performed on the light source 158 so as to be the same as the IST.

As described above, according to the image display apparatus and the method according to the thirty-second embodiment of the present invention, the brightness adjustment of the light source 158 is performed by providing the correlation with the signal amplitude control performed by the signal amplitude adjustment unit 153. To absorb the APL fluctuation of the output video signal with respect to the input video signal. Thereby, the light source 1
The visual contrast can be improved without increasing the average power consumption of 58.

In the thirty-second embodiment,
Feature detector 321, feature data generator 324 and second
The case where the configuration of the control data generation unit 325 is used in the image display device according to the fifteenth embodiment has been described, but the configuration is used in the image display devices according to the sixteenth to twenty-fifth embodiments. Can achieve the same effect.

(Thirty-third Embodiment) In the first to fourteenth embodiments, the case where the contrast adjustment is performed on the basis of the APL has been described. However, it is of course possible to adjust the contrast with reference to any other predetermined DC level. Therefore, in a thirty-third embodiment, an image display device that performs contrast adjustment based on an arbitrary predetermined DC level will be described.

FIG. 47 is a block diagram showing the structure of the image display device according to the thirty-third embodiment of the present invention. FIG.
In the image display device according to the thirty-third embodiment, the feature detection unit 11, the control data generation unit 332, the input signal processing unit 333, the light source control unit 16, the light receiving type light modulation unit 1
7 is provided. The input signal processing unit 333 includes a signal amplitude adjustment unit 333A and a DC level adjustment unit 333B. The light receiving type light modulator 17 includes a light source 18.

As shown in FIG. 47, the image display device according to the thirty-third embodiment comprises the control data generator 12 and the signal amplitude adjuster 1 of the image display device according to the first embodiment.
3 with the control data generator 332 and the input signal processor 3
33 instead of 33. Note that the other configuration of the image display device according to the thirty-third embodiment is the same as the configuration of the image display device according to the first embodiment, and the same configuration is denoted by the same reference numeral and described. Omitted. Less than,
An image display device according to a thirty-third embodiment of the present invention will be described focusing on components different from the image display device according to the first embodiment.

[0290] The control data generation unit 332 is
1 inputs the detected MAX and MIN, and a predetermined DC level (hereinafter referred to as LVL),
The adjusted DC level of the APL based on n, Offset, and LVL (hereinafter referred to as Offset2) is obtained as follows. First, the control data generation unit 332 converts the maximum amplitude (the difference between MAX and MIN) of the input video signal into a signal processable range of the processing circuit, that is, a dynamic range (specifically, the output of the signal amplitude adjustment unit 333A). Gain for amplifying up to the dynamic range width is obtained according to the following equation. Gain = dynamic range width / (MAX-MIN) The obtained gain is output to the signal amplitude adjustment unit 333A.

Next, the control data generation unit 332 outputs the Offset described in the first embodiment, MAX and M
From the IN and the gain obtained above, the signal amplitude adjusting unit 33
The input video signal after amplification performed by the 3A on the basis of the LVL gives the DC level that falls within the output dynamic range.
set2. This is to change the DC level of the amplified video signal so that the amplitude of the LVL-based amplified video signal falls within the dynamic range. The obtained Offset is sent to the light source control unit 16 for the Offset.
2 is output to the DC level adjustment unit 333B.

[0292] The signal amplitude adjustment unit 333A is provided with the input video signal and the Gain and LVL output from the control data generation unit 332.
Enter Then, the signal amplitude adjustment unit 333A outputs L
Based on VL, the input video signal is amplified according to Gain. The DC level adjustment unit 333B includes the amplified video signal output from the signal amplitude adjustment unit 333A and the control data generation unit 3
32 is input. And
The DC level adjustment unit 333B shifts the DC level of the amplified video signal to the value of Offset2. The amplified video signal (output video signal) after this level shift is
The image is output to the light receiving type light modulation unit 17 and displayed as an image.

As described above, according to the image display apparatus and method of the thirty-third embodiment of the present invention, the signal amplitude control performed by the input signal processing unit 333 (the signal amplitude adjustment unit 333A and the DC level adjustment unit 333B) The brightness of the light source 18 is adjusted with a correlation with the above, and the APL fluctuation of the output video signal with respect to the input video signal is absorbed. As a result, the sense of visual contrast can be improved without increasing the average power consumption of the light source 18.

[0294] In the thirty-third embodiment,
The case where the configurations of the control data generation unit 332 and the input signal processing unit 333 are used in the image display device according to the first embodiment has been described, but the configuration is not limited to the image according to the second to fourteenth embodiments. The same effect can be obtained even when used for a display device.

(Thirty-fourth embodiment) The fifteenth to thirty-fourth embodiments are described below.
In the thirty-second embodiment, Base and MA respectively
The case where the contrast adjustment is performed based on X, MIN, average value, and HIST has been described. However, it is of course possible to adjust the contrast with reference to any other predetermined DC level. Therefore, in a thirty-fourth embodiment, an image display device that performs contrast adjustment based on an arbitrary predetermined DC level will be described.

FIG. 48 is a block diagram showing the structure of the image display device according to the thirty-fourth embodiment of the present invention. FIG.
In the image display device according to the thirty-fourth embodiment, the feature display unit 151, the first control data generation unit 342,
An input signal processing unit 343, a feature data generation unit 344,
Second control data generation unit 155 and light source control unit 156
And a light receiving type light modulation unit 157. The input signal processing unit 343 includes a signal amplitude adjustment unit 343A and a DC level adjustment unit 343B. Light receiving type light modulator 157
Includes a light source 158.

As shown in FIG. 48, the image display device according to the thirty-fourth embodiment includes a first control data generator 152, a signal amplitude adjuster 153, and a feature of the image display device according to the fifteenth embodiment. In this configuration, the data generation unit 154 is replaced with a first control data generation unit 342, an input signal processing unit 343, and a feature data generation unit 344. The third
Other configurations of the image display device according to the fourth embodiment are the same as the configurations of the image display device according to the fifteenth embodiment, and the same reference numerals are given to the same components, and description thereof will be omitted. Hereinafter, an image display device according to a thirty-fourth embodiment of the present invention will be described, focusing on components different from the image display device according to the fifteenth embodiment.

The first control data generator 342 inputs MAX and MIN detected by the feature detector 151 and a predetermined arbitrary DC level (LVL), and converts Gain2 and Offset2 based on LVL into the following. Ask like. First, the first control data generation unit 342 determines the maximum amplitude (difference between MAX and MIN) of the input video signal as a signal processable range of the processing circuit, that is, a dynamic range (specifically, a signal amplitude adjustment unit). Gain for amplifying up to an output dynamic range of 343A) is obtained according to the following equation. Gain = dynamic range width /
(MAX-MIN) The obtained Gain is output to the signal amplitude adjustment unit 343A and the feature data generation unit 344.

Next, the first control data generator 342
From MAX and MIN and the above calculated Gain, Offset2 that gives a DC level within which the input video signal amplified by the signal amplitude adjustment unit 343A based on the LVL falls within the output dynamic range is obtained. This is to change the DC level of the amplified video signal so that the amplitude of the LVL-based amplified video signal falls within the dynamic range. The calculated Offset2 is output to the DC level adjustment unit 343B and the feature data generation unit 344.

The signal amplitude adjusting section 343A receives the input video signal and the Gain and LVL output from the first control data generating section 342. Then, the signal amplitude adjusting unit 343A
Amplifies an input video signal in accordance with Gain with reference to LVL. The DC level adjustment unit 343B receives the amplified video signal output from the signal amplitude adjustment unit 343A and Offset2 output from the first control data generation unit 342. Then, the DC level adjusting unit 343B shifts the DC level of the amplified video signal to the value of Offset2. The amplified video signal (output video signal) after this level shift is output to the light receiving type light modulation section 157 and displayed as an image.

[0301] The feature data generation unit 344 is
APL detected by the first control data generation unit 34
2, the Gain and Offset2 obtained and LVL are input. Then, the feature data generation unit 344 determines that the AP
Average luminance level (APL2) in the output video signal based on L, Gain, Offset2 and LVL
Ask for. This APL2 is the second control data generator 1
55.

As described above, according to the image display apparatus and method of the thirty-fourth embodiment of the present invention, the signal amplitude control performed by the input signal processing unit 343 (the signal amplitude adjustment unit 343A and the DC level adjustment unit 343B) And adjusts the brightness of the light source 158 so as to have a correlation with the input video signal, thereby absorbing the APL variation of the output video signal with respect to the input video signal. This allows
The visual sense of contrast can be improved without increasing the average power consumption of the light source 158.

In the thirty-fourth embodiment,
First control data generator 342, input signal processor 343
The case where the configuration of the feature data generation unit 344 is used in the image display device according to the fifteenth embodiment has been described, but the configuration is used in the image display devices according to the sixteenth to thirty-second embodiments. Can achieve the same effect. In this case, the feature data generation unit 344 performs APL, MAX, and MI corresponding to each of the above-described embodiments.
NPL or HIST, APL2,
Either AVE or HIST2 will be output.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of an outline of a process performed by an image display device according to a first embodiment of the present invention on a certain input video signal.

FIG. 3 is a diagram illustrating an example of an outline of a process performed by the image display device according to the first embodiment of the present invention on a certain input video signal.

FIG. 4 is a block diagram illustrating a configuration of an image display device according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating a configuration of an image display device according to a third embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of an image display device according to a fourth embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of an outline of a process performed by an image display device according to a fourth embodiment of the present invention on a certain input video signal.

FIG. 8 is a block diagram illustrating a configuration of an image display device according to a fifth embodiment of the present invention.

FIG. 9 is a block diagram illustrating a configuration of an image display device according to a sixth embodiment of the present invention.

FIG. 10 is a block diagram illustrating a configuration of an image display device according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram showing a configuration of an image display device according to an eighth embodiment of the present invention.

12 is a diagram illustrating an example of an inverse gamma characteristic in an inverse gamma correction processing unit 81 and a gamma control data generation unit 85 in FIG. 11;

FIG. 13 is a block diagram illustrating a configuration of an image display device according to a ninth embodiment of the present invention.

FIG. 14 is a block diagram illustrating a configuration of an image display device according to a tenth embodiment of the present invention.

15 is a timing chart illustrating an example of a correction process performed by a control data correction unit 101 in FIG.

FIG. 16 is a block diagram illustrating a configuration of an image display device according to an eleventh embodiment of the present invention.

FIG. 17 is a diagram showing an example in which two screens are displayed on the light receiving type light modulation unit 17 of FIG. 16;

FIG. 18 shows an eleventh embodiment of the present invention for a certain input video signal;
FIG. 8 is a diagram for explaining an example of an outline of a process performed by the image display device according to the embodiment.

FIG. 19 is a block diagram illustrating a configuration of an image display device according to a twelfth embodiment of the present invention.

FIG. 20 is a block diagram illustrating a configuration of an image display device according to a thirteenth embodiment of the present invention.

FIG. 21 is a block diagram illustrating a configuration of an image display device according to a fourteenth embodiment of the present invention.

FIG. 22 is a block diagram illustrating a configuration of an image display device according to a fifteenth embodiment of the present invention.

FIG. 23 shows a fifteenth embodiment of the present invention for a certain input video signal;
FIG. 8 is a diagram for explaining an example of an outline of a process performed by the image display device according to the embodiment.

FIG. 24 is a block diagram illustrating a configuration of an image display device according to a sixteenth embodiment of the present invention.

FIG. 25 is a block diagram illustrating a configuration of an image display device according to a seventeenth embodiment of the present invention.

FIG. 26 shows a seventeenth embodiment of the present invention for a certain input video signal;
FIG. 8 is a diagram for explaining an example of an outline of a process performed by the image display device according to the embodiment.

FIG. 27 is a block diagram illustrating a configuration of an image display device according to an eighteenth embodiment of the present invention.

FIG. 28 is a block diagram illustrating a configuration of an image display device according to a nineteenth embodiment of the present invention.

FIG. 29 is a block diagram illustrating a configuration of an image display device according to a twentieth embodiment of the present invention.

FIG. 30 is a block diagram illustrating a configuration of an image display device according to a twenty-first embodiment of the present invention.

31 is a diagram illustrating an example of an inverse gamma characteristic in the inverse gamma correction processing unit 211 and the second control data generation unit 215 in FIG.

FIG. 32 is a block diagram illustrating a configuration of an image display device according to a twenty-second embodiment of the present invention.

FIG. 33 is a block diagram illustrating a configuration of an image display device according to a twenty-third embodiment of the present invention.

FIG. 34 is a timing chart illustrating an example of a correction process performed by the control data correction unit 231 of FIG. 33.

FIG. 35 is a block diagram showing a configuration of an image display device according to a twenty-fourth embodiment of the present invention.

FIG. 36 shows a twenty-fourth embodiment of the present invention for an input video signal.
FIG. 8 is a diagram for explaining an example of an outline of a process performed by the image display device according to the embodiment.

FIG. 37 is a block diagram illustrating a configuration of an image display device according to a twenty-fifth embodiment of the present invention.

FIG. 38 is a block diagram illustrating a configuration of an image display device according to a twenty-sixth embodiment of the present invention.

FIG. 39 is a block diagram showing a configuration of an image display device according to a twenty-seventh embodiment of the present invention.

FIG. 40 is a diagram illustrating an input video signal according to the 27th embodiment of the present invention.
FIG. 8 is a diagram for explaining an example of an outline of a process performed by the image display device according to the embodiment.

FIG. 41 is a block diagram illustrating a configuration of an image display device according to a twenty-eighth embodiment of the present invention.

FIG. 42 is a diagram illustrating an input video signal according to the twenty-eighth aspect of the present invention;
FIG. 8 is a diagram for explaining an example of an outline of a process performed by the image display device according to the embodiment.

FIG. 43 is a block diagram illustrating a configuration of an image display device according to a twenty-ninth embodiment of the present invention.

FIG. 44 is a block diagram illustrating a configuration of an image display device according to a thirtieth embodiment of the present invention.

FIG. 45 is a block diagram illustrating a configuration of an image display device according to a thirty-first embodiment of the present invention.

FIG. 46 is a block diagram illustrating a configuration of an image display device according to a thirty-second embodiment of the present invention.

FIG. 47 is a block diagram illustrating a configuration of an image display device according to a thirty-third embodiment of the present invention.

FIG. 48 is a block diagram illustrating a configuration of an image display device according to a thirty-fourth embodiment of the present invention.

[Explanation of symbols]

11,61,121,151,191,251,29
1,301,311,321 ... feature detection unit 12,42,52,72,122,135,145,1
52,155,172,185,202,215,25
2,272,282,292,295,305,31
2, 315, 325, 332, 342 ... control data generation unit 13, 293, 313, 333, 343 ... input signal processing unit 13A, 112, 125, 153, 242, 255, 2
73, 283, 293A, 313A, 333A, 343
A: Signal amplitude adjustment unit 13B, 293B, 313B, 333B, 343B ... D
C-level adjustment unit 16, 156: light source control unit 17, 157: light receiving type light modulation unit 18, 158: light source 31, 161: noise control data generation unit 32, 162: noise reduction unit 41, 51, 171, 181: data Judgment units 81, 91, 211, 221 Gamma reverse correction processing unit 85 Gamma control data generation units 101, 231 Control data correction units 111, 124, 241, 254 Correction data generation units 113, 123, 243, 253 MIX 134, 264... Output signal feature detection section 144, 154, 274, 284, 304, 324, 3
44 ... characteristic data generation unit

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuyuki Arimoto 1006 Odakadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-62-119835 (JP, A) JP-A-5 -127608 (JP, A) JP-A-6-102484 (JP, A) JP-A-11-109317 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) G09G 3/36 G02F 1/133 535 G09G 3/20 642 G09G 3/34 H04N 5/66 102

Claims (6)

(57) [Claims]
1. An image display device for displaying an input video signal which has been subjected to a gamma correction process in advance on a light receiving type light modulating means having a light source, wherein said video signal (hereinafter referred to as a main video signal) is A feature detecting means for inputting and detecting a maximum luminance level (hereinafter, described as MAX), a minimum luminance level (hereinafter, described as MIN), and an average luminance level (hereinafter, described as APL) of the main video signal, MAX, MIN, and APL are input, and a gain for amplifying the maximum amplitude of the main video signal (difference between MAX and MIN) to the output dynamic range width of the DC level adjusting means, and the signal amplitude adjusting means. Control data generating means for obtaining an offset giving a DC level shift amount within which the main video signal falls within the output dynamic range; Input the video signal, APL and gain,
The signal amplitude adjusting means for amplifying the main video signal in accordance with the gain with reference to the PL; and the amplified main video signal and the offset output from the signal amplitude adjusting means, and the amplified main video signal DC level adjusting means for level-shifting the DC level according to the offset value, and inverse gamma correction for inputting the main video signal level-shifted by the DC level adjusting means and canceling out the gamma correction processing being performed After performing the processing, the gamma inverse correction processing means for outputting to the light receiving type light modulation means, and the offset are input, and the same inverse gamma correction processing as that performed by the gamma inverse correction processing means is performed on the offset. Gamma control data generating means, inputting the inverse gamma corrected offset output by the gamma control data generating means, APL when an image is displayed on the light receiving type light modulation means based on the offset,
An image display device comprising: a light source control unit that performs light source luminance control so as to turn on the light source to a brightness equivalent to APL in the main video signal.
2. An image display device for displaying an input video signal which has been subjected to a gamma correction process in advance on a light receiving type light modulating means having a light source, wherein said input video signal is applied to said video signal. A gamma inverse correction processing unit for performing an inverse gamma correction process for canceling the gamma correction process; and the video signal (hereinafter, referred to as a main video signal) that has been inverse gamma-corrected by the gamma inverse correction processing unit, and the main video signal is input. A characteristic detecting means for detecting a maximum luminance level (hereinafter, referred to as MAX), a minimum luminance level (hereinafter, referred to as MIN), and an average luminance level (hereinafter, referred to as APL) of the signal; A gain for amplifying the maximum amplitude (difference between MAX and MIN) of the main video signal up to the output dynamic range width of the DC level adjusting means; Control data generating means for obtaining an offset giving a DC level shift amount within which the main video signal amplified by the signal amplitude adjusting means falls within the output dynamic range; and inputting the main video signal, APL, and gain;
The signal amplitude adjusting means for amplifying the main video signal in accordance with the gain with reference to a PL, and the amplified main video signal and the offset output from the signal amplitude adjusting means, and the amplified main video signal Is shifted according to the value of the offset, and the DC level is output to the light receiving type light modulating means.
A level adjusting unit, and inputting the offset, and turning on the light source to a brightness at which an APL when an image is displayed on the light receiving type light modulating unit based on the offset is equivalent to an APL in the main video signal. Image display device, comprising: a light source control unit that performs light source luminance control as described above.
3. An image display device for displaying an input video signal which has been subjected to a gamma correction process in advance on a light receiving type light modulation means having a light source, wherein said video signal (hereinafter referred to as a main video signal) is displayed. A feature detecting means for inputting and detecting a maximum luminance level (hereinafter, described as MAX), a minimum luminance level (hereinafter, described as MIN), and an average luminance level (hereinafter, described as APL) of the main video signal, MAX and MIN are input, a gain for amplifying the maximum amplitude of the main video signal (difference between MAX and MIN) up to the output dynamic range width of the signal amplitude adjusting means, and the amplified main video signal is Control data generating means for obtaining a base for providing an amplification reference level for falling within an output dynamic range; and inputting the main video signal, a gain and a base. Amplifying the main video signal according to the gain with the base as a reference, the signal amplitude adjustment unit outputting the light-receiving type light modulation unit, and the main video signal amplified by the signal amplitude adjustment unit, After performing an inverse gamma correction process for canceling the applied gamma correction process, inputting the APL, the gain, and the base to the gamma inverse correction processing unit to output to the light receiving type light modulation unit, and
A characteristic data generating unit that generates an average luminance level (hereinafter, referred to as a second APL) of the amplified main video signal output from the signal amplitude adjusting unit based on L, a gain, and a base; The second APL is input, the same inverse gamma correction processing as that performed by the inverse gamma correction processing means is performed, and an image is transmitted to the light receiving type light modulation means based on the difference between the APL and the second APL. APL when displayed
A second control data generating means for generating light source luminance control data for lighting the light source to a brightness equivalent to the APL in the main video signal; An image display device comprising: light source control means for performing control.
4. An image display apparatus for displaying an input video signal which has been subjected to a gamma correction process in advance on a light receiving type light modulating means having a light source, wherein said input video signal is applied to said video signal. A gamma inverse correction processing unit for performing an inverse gamma correction process for canceling the gamma correction process; and the video signal (hereinafter, referred to as a main video signal) that has been inverse gamma-corrected by the gamma inverse correction processing unit, and the main video signal is input. A characteristic detecting means for detecting a maximum luminance level (hereinafter, referred to as MAX), a minimum luminance level (hereinafter, referred to as MIN), and an average luminance level (hereinafter, referred to as APL) of the signal; A gain for amplifying the maximum amplitude of the main video signal (difference between MAX and MIN) up to the output dynamic range width of the signal amplitude adjusting means; Control data generating means for obtaining a base for providing an amplification reference level for the main video signal to fall within the output dynamic range; and inputting the main video signal, a gain and a base, and applying the gain based on the base based on the gain. The signal amplitude adjusting means for amplifying the main video signal and outputting the amplified signal to the light receiving type light modulating means;
A characteristic data generating unit that generates an average luminance level (hereinafter, referred to as a second APL) of the amplified main video signal output from the signal amplitude adjusting unit based on L, a gain, and a base; The second APL is input, and based on the difference between the APL and the second APL, the APL when displaying an image on the light receiving type light modulating means is the APL in the main video signal.
A second control data generating unit that generates light source luminance control data for lighting the light source to a brightness equivalent to PL; and a light source control unit that performs light source luminance control by using the light source luminance control data as input. An image display device.
5. An image display method for displaying an input video signal which has been subjected to a gamma correction process in advance on a light receiving type light modulating means having a light source, wherein said video signal (hereinafter referred to as a main video signal) On the other hand, the maximum luminance level of the main video signal (hereinafter referred to as MAX),
Detecting a minimum luminance level (hereinafter, referred to as MIN) and an average luminance level (hereinafter, referred to as APL); and detecting a maximum amplitude of the main video signal (difference between MAX and MIN) with the light-receiving light modulation. Determining a gain for amplifying to an output dynamic range width for the means, and an offset giving a DC level shift amount within which the main video signal amplified according to the gain falls within the output dynamic range; Amplifying the main video signal in accordance with the gain; and inverting the DC level of the amplified main video signal in accordance with the offset value, and inverting the gamma correction being performed. Performing a process and outputting the processed light to the light receiving type light modulating means; Applying the inverse gamma correction processing to the light-receiving light modulating means based on the offset subjected to the inverse gamma correction processing.
Controlling the light source brightness so that the light source is turned on so that the brightness becomes equal to the APL in the main video signal.
6. An image display method for displaying an input video signal which has been subjected to a gamma correction process in advance on a light receiving type light modulation means having a light source, wherein the input video signal is applied to the video signal. Performing a reverse gamma correction process for canceling the gamma correction process; and providing the inverse gamma corrected video signal (hereinafter, referred to as a main video signal) with a maximum luminance level (hereinafter, referred to as MAX) of the main video signal. ), Minimum luminance level (hereinafter, MI)
N) and an average luminance level (hereinafter, referred to as APL), respectively, and a maximum amplitude (difference between MAX and MIN) of the main video signal is determined by an output dynamic range width with respect to the light receiving type light modulating means. Obtaining a gain for amplifying the main video signal amplified according to the gain, and a base for providing an amplification reference level for keeping the main video signal within the output dynamic range. Amplifying the video signal and outputting the amplified video signal to the light receiving type light modulating means; and, based on the APL, gain and base, an average luminance level of the amplified main video signal (hereinafter referred to as a second APL).
), And based on a difference between the APL and the second APL, a brightness at which an APL when an image is displayed on the light receiving type light modulating means is equivalent to an APL in the main video signal. An image display method, further comprising: generating light source luminance control data for turning on the light source; and performing light source luminance control based on the light source luminance control data.
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JP4568369B1 (en) 2009-07-07 2010-10-27 株式会社東芝 Light source control device and liquid crystal display device including the same
JP5472268B2 (en) * 2011-11-18 2014-04-16 ソニー株式会社 Display device and driving method thereof

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US7382414B2 (en) 2003-12-10 2008-06-03 Hitachi, Ltd. Video signal processing apparatus, for controlling contrast compensation and edge compensation in relation to each other in depedence on luminance of an image, and television receiver including the same
US8232956B2 (en) 2005-10-18 2012-07-31 Sharp Kabushiki Kaisha Liquid crystal display apparatus

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