JPH08163469A - Image display device - Google Patents

Abstract

PURPOSE: To obtain the image display device in which distortion of an image, whose aspect ration is converted, is reduced. CONSTITUTION: Suppose that five circular images 2 are included in an original image 1 whose aspect ratio is 4:3 and the image is converted into an image for an image display section 5 whose aspect ratio is 16:9, then a prescribed visual field 6 around a visual line in response to the detection of a sight sensor 3 of an eye 4 is decided for a display plane. Circular images 2a, 2b having distortion due to aspect conversion are displayed on the display plane and when the sight is moved and the visual field 6 is moved attended therewith, the aspect ratio conversion is controlled so that the distorted circular images 2a, 2b displayed at the outside of the visual field 6. As a control method, a write clock of a frame memory storing, e.g. the original image is controlled. Since the image distortion part is displayed at the outside of the visual field of the viewer in the display plane at all times, the distortion is not a matter of disturbance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device having an aspect conversion function.

[0002]

2. Description of the Related Art Conventionally, high-definition TVs,
In order to display a video signal with an aspect ratio of 4: 3 in the conventional NTSC system or PAL system on an image display device with an aspect ratio of 16: 9 such as a wide TV called a wide vision, the image is partially compressed, A function of converting and displaying the aspect ratio by performing processing such as expansion and thinning is known. FIGS. 8A to 8E show examples of such aspect conversion.

In aspect conversion, for example, when an NTSC 4: 3 screen is to be displayed in a 16: 9 screen area, if it is enlarged in a similar form, it is unused on both left and right sides of the screen as shown in FIG. 8 (a). The black part of the image appears, or
As in (b), since the upper and lower parts are out of the display area, the entire screen cannot be displayed on the entire 16: 9 effective screen. Therefore, by compressing (thinning) the upper and lower regions or extending the left and right ends, the center region remains almost 1: 1 and the upper and lower or left and right ends are flattened in the horizontal direction as shown in FIG. 8C. 8 screen conversion, conversion to flatten the entire screen as shown in FIG.
As shown in (e), the entire NTSC screen can be displayed on the entire 16: 9 effective screen by using conversion such that only the subtitle display area under the screen is flat.

[0004]

However, in the conventional example shown in FIGS. 8 (c) to 8 (e), part or all of the screen is flat with respect to the original image, so that part is seen. Sometimes it had the drawback of appearing unnaturally as screen distortion.
In particular, in a viewfinder section of a video camera or a small-screen display device placed close to the eyes such as a head-mounted type display, in order to easily see the entire screen with a small eye movement, These screen distortions are more noticeable than those on large screens.

The present invention has been made to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide an image display device capable of reducing distortion of an image whose aspect has been converted.

[0006]

According to a first aspect of the present invention, in an image display device having an aspect conversion function, a line-of-sight detecting unit for detecting a line-of-sight on a display screen and a detection signal of the line-of-sight detecting unit are provided. A control means for controlling the aspect conversion operation is provided.

According to the second aspect of the invention, the control means controls so that the distorted portion generated in the aspect-converted image is displayed outside the visual field on the display screen.

In the invention of claim 3, the control means is provided with a storage means for writing the original image signal, and controls the write clock thereof.

According to a fourth aspect of the present invention, a liquid crystal panel having a display screen, a visual axis detecting means for detecting a visual axis on the display screen, and a driving means for driving the liquid crystal panel in horizontal and vertical directions by shift pulse input. And control means for performing aspect conversion by controlling shift pulses in both or one of the horizontal and vertical directions according to the detection signal of the line-of-sight detection means.

[0010]

According to the first aspect of the invention, the image distortion caused by the conversion is reduced by limiting the operation of the aspect conversion according to the detection of the line of sight.

According to the second aspect of the present invention, the image distortion is not noticed to the observer by controlling the image distortion portion so as to be out of the line of sight of the observer on the display screen.

According to the third aspect of the present invention, the image distortion portion can be displayed outside the line of sight by controlling the write clock of the storage means in which the original image signal is written according to the line of sight detection.

According to the fourth aspect of the present invention, by controlling the shift pulse for driving the liquid crystal panel in the horizontal and vertical directions according to the visual axis detection, it is possible to display the image distorted portion outside the visual axis.

[0014]

【Example】

[First Embodiment] FIGS. 1, 2 and 3 show a first embodiment of the present invention. FIG. 2 shows the operation that best represents the features of the present invention, in which 1 indicates an original image signal having a conventional aspect ratio of 4: 3, and here, for the sake of explanation, five circular images indicated by 2 are projected. ing. Reference numeral 3 denotes a sensor that detects the direction of the line of sight. Reference numeral 3a represents reference light to be detected, and 3b represents reflected light from the eye. 4 shows a view of the human eye as seen from the lateral direction. Reference numeral 5 denotes an image display unit having an aspect ratio of 16: 9. Here, the inside of the dotted circle indicated by 6 indicates the approximate visual field portion that is gazing.

FIG. 2A shows 4: 3 before aspect ratio conversion.
2 (b) to 2 (d) show images after aspect ratio conversion in 16: 9 by compressing in the vertical direction. The center of the line of sight of the field of view 6 is in the middle of (b), (c). Shows the lower case, and (d) shows the upper case. The movement of the line of sight is detected by the sensor 3, and the region where the image is compressed is changed to be the region outside the visual field 6. A known sensor can be used as the line-of-sight detection sensor 3.

FIG. 1 is a block diagram of an image display device according to the first embodiment, and FIG. 3 shows operation timing. Here, a case is shown in which the work of compressing the image in the vertical (V) direction outside the field of view 6 is realized by controlling the clock that determines the address in the V direction when writing to the frame memory according to the movement of the line of sight. There is.

In FIG. 1, 7 is an RGB decoder section for decoding an input video signal (original signal) into RGB color signals, 8 is an A / D conversion section, 9 is a frame memory for 2 fields of each color of RGB, and 10 is D. An A / A converter 11 is an address controller that controls the write address control clock VCLK in the V direction in accordance with the line-of-sight detection signal from the sensor 3 to determine the address in the frame memory 9.

In FIG. 3, reference numeral 12 shows a simplified scanning line in the original image signal 1. l, l + 1, l +
2 and l + 3 are interlaced and adjacent 4
Scan lines, where m, m + 1, m + 2, m + 3 are four interlaced adjacent central lines, and n, n + 1, n + 2, n + 3 are interlaced and four adjacent lower lines. The scan lines are shown. l +
Among α, m + α, and n + α (α = 0, 1, 2, 3), the dotted line indicates the odd field signal, and the solid line indicates the even field signal. 13a and 13b are od
Horizontal (H) in d field and even field
The original signal of the period is shown.

Reference numerals 14a and 14b are V-direction address control clocks for writing in the frame memory when the line of sight is at the center of the screen, and when the level becomes H level, the horizontal line to be written in the frame memory 9 is selected. . The V-direction address control clocks 14a and 14b are used for the odd field and ev, respectively.
It is a clock in the en field. 5a is the frame memory 9 written by the clocks 14a and 14b.
It is an image in which the signal of is interlaced and displayed on a screen having an aspect ratio of 16: 9. Here, the upper l + 1 and l + 2 lines and the lower n + 1 and n + 2 lines are thinned out and recorded in the frame memory 9, whereby the upper and lower images are compressed.

Reference numerals 15a and 15b are V-direction address control clocks for writing in the frame memory when the line of sight is at the lower part of the screen, and respectively show clocks in the odd field and the even field. 5b is an image in which the signals of the frame memory 9 written by the clocks 15a and 15b are interlaced and displayed on a 16: 9 screen. Here, l, l + at the top of the screen
The upper part of the image is compressed by thinning out 1 and l + 3 and recording them in the frame memory 9.

As described above, by selecting and switching the V-direction address control clocks 14a, 14b, 15a, 15b in accordance with the direction of the line of sight, the image distortion can be reduced as shown in FIG.
The field of view 6 is removed from the center.

By doing so, when the field of view 6 is located approximately in the center of the image display section 5 as shown in FIG.
The upper and lower two circular images 2a and 2b are distorted and displayed, but the other three circular images 2 are displayed as perfect circles. In this case, a person who looks at the image display unit 5 can see only the circular image 2 in the visual field 6 as a perfect circle, and the distorted circular images 2a and 2b do not enter the visual field 6, so the distortion is not a concern.

In FIGS. 2B and 2C, the field of view 6 is the image display unit 5.
In the above case, the upper and lower circular images 2a or 2b are distorted and the field of view 6 is shown.
Since the inner circle image 2 looks like a perfect circle, distortion is not a concern.

[Second and Third Embodiments] FIGS. 4 and 5 are block diagrams and operation timing diagrams of the second and third embodiments. In FIG. 4, the liquid crystal panel 5 is used as an image display unit.
c is used. Reference numeral 16 denotes an amplifier unit that uses the color signals decoded by the RGB decoder unit 7 as liquid crystal driving inversion signals, and 18 and 19 are horizontal and vertical shift registers for transferring the signals to the pixels of the liquid crystal panel 5c. Reference numeral 17 denotes a shift register control unit that controls transfer pulses of the shift registers 18 and 19 according to the direction of the line of sight detected by the sensor 3.

In FIG. 5, 13c indicates the original signal in the horizontal period. Reference numeral 21 is a blanking period, and 22 is an effective horizontal scanning period. Therefore, 21 + 22 = 1 horizontal scanning period (1H) = 63.5 μs. 20a,
20b, 20c and 20d are horizontal (H) shift registers 1
8 shift pulses are shown. A signal is transferred to the signal line in the horizontal direction each time the H level is input.

FIG. 6 shows a second embodiment image realized by the circuit of FIG. 4 and the timing of FIG. 6A is an original image, and FIG. 6B is a shift pulse 20 of the horizontal shift register 18 of FIG. 5 in the circuit of FIG.
The image on the screen of 16: 9 realized by a is shown.
FIG. 6C shows a 16: 9 realized by the shift pulse 20b of the horizontal shift register 18 of FIG. 5 in the circuit of FIG.
Shows an image on the screen of. 4b shows both eyes seen from above.

In FIG. 4 and FIG. 5, the horizontal shift pulse 20a for pixels corresponding to both sides of the 16: 9 screen is blanked in the blanking period 21, so that FIG.
In the liquid crystal panel 5c as shown in (b), the non-displayed portions 5 are provided on both sides
d is formed, and a 4: 3 image is displayed in the center of the 16: 9 screen.

In FIGS. 4 and 5, since the horizontal shift pulse 20b corresponding to the pixel on the right side of the screen is blanked out within the blanking period 21, a 16: 9 screen is displayed as shown in FIG. 6C. A non-display portion 5e is formed on the right side, and 16:
9: A 4: 3 image is displayed on the left side of the screen.

As described above, the horizontal shift pulses 20a, 20
As shown in FIG. 6, the non-display portions 5d, 5d are displayed outside the field of view by selectively switching b depending on the detection signal of the sensor 3.
e is formed to eliminate the uncomfortable feeling when displaying on the 16: 9 liquid crystal panel 5c.

FIG. 7 shows an image of the third embodiment implemented with the circuit of FIG. 4 and the timing of FIG. Here, the original image is realized by the shift pulse 20c of the horizontal shift register 18 of FIG. 5 in the circuit of FIG. 4 in contrast to FIG. 6 (a) which is the same as in the second embodiment, 16: 9. The image on the screen is shown. FIG. 7B shows an image on the 16: 9 screen realized by the shift pulse 20d of the horizontal shift register 18 of FIG. 5 in the circuit of FIG.

In FIG. 5, the effective horizontal scanning period 2
By shifting at a timing closer to that of the central portion in the left and right regions between the two, an image having both ends extended as shown in FIG. 7C is realized.

In FIG. 5, the effective horizontal scanning period 2
In the right area of 2, the shift is performed at a timing closer to the left and central portions, so that an image in which the right screen is expanded as shown in FIG. 7C is realized.

Also in this embodiment, by selectively switching the horizontal shift pulses 20c and 20d in accordance with the detection signal of the sensor 3, the image distortion is moved to a region outside the visual field as shown in FIG. 7, and the 16: 9 panel is displayed. On 4: 3 image 5
The discomfort when displaying the whole f and 5g is removed.

According to each of the above-mentioned embodiments, when a part of the original image signal is compressed or expanded and displayed on the entire screen,
By bringing the area with screen distortion to the area out of the visual field based on the detected line of sight, the discomfort on the image is removed and the function to display a powerful image larger than the screen size is provided. It becomes possible.

Further, by selectively switching the address control at the time of writing to the frame memory 9 by the line-of-sight detection signal as in the first embodiment, the above-mentioned function can be realized with a relatively easy structure and low cost. .

Also, by selectively switching the shift pulses of the horizontal and vertical shift registers 18 and 19 according to the line-of-sight detection signal as in the second and third embodiments, the above-mentioned functions can be easily and cost-effectively as described above. Can be realized.

[0037]

As described above, according to the invention of claim 1, since the aspect conversion operation is controlled in accordance with the sight line detection, the image distortion caused by the conversion can be reduced. is there.

According to the second aspect of the invention, the image distortion portion is controlled so as to be out of the line of sight of the observer on the display screen, so that the image distortion is not noticed by the observer. There is.

According to the third aspect of the present invention, since the writing clock of the storage means in which the original image signal is written is controlled according to the detection of the line of sight, the image distortion portion can be displayed outside the line of sight. effective.

According to the invention of claim 4, by controlling the shift pulse for driving the liquid crystal panel in the horizontal and vertical directions according to the detection of the line of sight, it is possible to display the image distorted portion outside the visual field. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the operation of the first embodiment.

FIG. 3 is a timing chart showing the operation of the first embodiment.

FIG. 4 is a block diagram showing second and third embodiments of the present invention.

FIG. 5 is a timing chart showing the operation of the second and third embodiments.

FIG. 6 is an explanatory diagram showing the operation of the second embodiment.

FIG. 7 is an explanatory diagram showing the operation of the third embodiment.

FIG. 8 is an explanatory diagram showing conventional aspect conversion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 original image signal 3 line-of-sight detection sensor 5 image display unit 9 frame memory 11 address control unit 5c liquid crystal panel 17 shift register control unit 18 horizontal shift register 19 vertical shift register

Claims (5)

[Claims] 1. An image display device having an aspect conversion function, comprising line-of-sight detection means for detecting a line-of-sight on a display screen, and control means for controlling the operation of the aspect conversion according to a detection signal of the line-of-sight detection means. An image display device characterized by being provided. 2. An image distortion portion due to conversion generated in a part of the image obtained by the aspect conversion is in an area outside a predetermined visual field including the line of sight on the display screen detected by the line of sight detecting means. The image display device according to claim 1, wherein the image display device is controlled so as to be displayed. 3. A storage means for writing an original image signal is provided, and the aspect conversion is realized by controlling a write address clock given to the storage means by the control means in accordance with a detection signal of the line-of-sight detection means. The image display device according to claim 1, wherein 4. A liquid crystal panel having a display screen, line-of-sight detection means for detecting a line-of-sight on the display screen, driving means for driving the liquid crystal panel in horizontal and vertical directions by shift pulses, and the line-of-sight detection means. An image display apparatus comprising: a control unit that performs aspect conversion by controlling a shift pulse in both or one of horizontal and vertical directions according to a detection signal. 5. The image according to claim 1 or 4, wherein the aspect conversion is a conversion for displaying an original image signal having an aspect ratio of 4: 3 on a screen having an aspect ratio of 16: 9. Display device.