JPH11252458A - Aspect correcting device and camera using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display in a correct aspect ratio by making the ratio of the number of scan lines to the number of pixels in a liquid crystal display device agree with the ratio the number of scan lines to the number of pixels in an output signal from a solid-state image-pickup device. SOLUTION: First, vertical thinning drive for compressing 5.57% for a vertical distortion part is instructed to an LCD panel, when a CCD output is shown on the LCD panel. That is, since a vertical output becomes 256 lines when the CCD performs a thinning read mode, 13.5 lines are thinned out from the 256 lines to accommodate them in 242.5 lines that are effective in an NTSC system. Also, about a horizontal direction, vertical compression for a part corresponding to 1.73% compression is performed. Thus, the 5.57% for the vertical distortion part is compressed by utilizing a function which performs the vertical thinning drive, further more vertical compression for a part corresponding only to the horizontal distortion part is performed for extending the 1.73% horizontal distortion portion to have both the vertical and horizontal directions corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CCD (Charge C)
output from a solid-state imaging device such as an
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aspect correction device for correcting an aspect ratio (aspect ratio) of an image when a visible image is formed on a liquid crystal display device such as a (Liquid Crystal Display) panel, and a camera using the same.

[0002]

2. Description of the Related Art In general, a CCD used as an imaging device of a video camera is an NTSC (National Televis).
ion System Committee) or PAL (Phase Alte)
(Rating by Line) method. That is, the effective pixel ratio of this CCD (the number of CCD effective pixels during one horizontal period / H synchronization signal period or the number of effective lines during one vertical period / V synchronization signal period) and N
The effective ratio (effective area in one horizontal period / H synchronization signal cycle or effective area in one vertical period / V synchronization signal cycle) defined by the TV standard such as the TSC system or the PAL system is almost the same. Therefore, C for video camera
In the case of a CD, as shown in FIGS. 4A and 4B, even when the CCD output is displayed on an LCD panel and monitored, the aspect ratio of the image read by the CCD and the image displayed on the LCD panel are displayed. Does not differ from the aspect ratio.

In recent years, in addition to video cameras, electronic still cameras that use a CCD as an image pickup device and perform digital photograph recording have become widespread. An electronic still camera usually uses a so-called all-pixel readout CCD in order to realize high resolution. However, in cases where high resolution is not required, such as when checking the composition of a subject, the monitoring mode (thinning-out reading mode) in which signal charges are read from only a part of the pixel rows in the vertical direction (for example, 分 line) is used. It has been adapted.

A CC used by such an electronic still camera
D is roughly classified into VGA (Video Graphics Arr
ay) Class compatible with 330,000 pixels and XGA
(Extended Graphics Array) classes are available for 800,000 pixels. As for the VGA class CCD, if signal charges are read out in the monitoring mode, FIG.
As shown in (c), even when the CCD output is displayed on the LCD panel and monitored, a difference occurs between the aspect ratio of the image read by the CCD and the aspect ratio of the image displayed by the LCD panel. There is no end.

[0005]

However, the XGA
In the CCD of the class, the horizontal effective pixel ratio is lower than the horizontal effective ratio in the TV standard, and the vertical effective pixel ratio is higher than the vertical effective ratio in the TV standard. Therefore, if the XGA class CCD output is displayed on the LCD panel as it is, the displayed image is as shown in FIG.
As shown in the figure, the image read by the CCD is enlarged by 5.57% in the vertical direction and compressed by 1.73% in the horizontal direction. That is, a difference occurs between the aspect ratio of the image read by the CCD and the aspect ratio of the image displayed by the LCD panel, so that the LCD panel displays a vertically long image as a whole.

In order to correct such a difference in aspect ratio, for example, as disclosed in Japanese Patent Application Laid-Open No. 8-336090, a VRAM (Video Random Access Memory) is temporarily provided before a CCD output is displayed on an LCD panel. Access Memo
ry) may be written to the image processing memory. That is, it is conceivable to correct the aspect ratio by controlling reading from the image processing memory. However, in this case, a memory for image processing such as a VRAM is required, which complicates the configuration for displaying the CCD output on the LCD panel. In addition, since the image processing memory is expensive, realizing the configuration leads to an increase in cost.

Accordingly, the present invention makes it possible to correct an aspect ratio without requiring an image processing memory such as a VRAM, and to read an image with an aspect ratio different from that of a liquid crystal display device such as an XGA class CCD. It is an object of the present invention to provide an aspect correction device capable of correctly displaying an output signal from a solid-state imaging device on a liquid crystal display device, and a camera using the same.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to an aspect correction apparatus devised to achieve the above-mentioned object, which can perform a vertical thinning drive for thinning out and displaying a part of vertical scanning lines. For displaying an output signal from a solid-state imaging device that performs image reading at an aspect ratio different from that of the liquid crystal display device using a liquid crystal display device, and the number of scanning lines in the vertical direction of the liquid crystal display device. Vertical correction means for performing the vertical thinning drive based on the ratio of the number of vertical scanning lines of the output signal to the output signal; the number of horizontal pixels of the liquid crystal display device; and the number of horizontal pixels of the output signal. And a horizontal direction correcting means for performing the vertical thinning-out drive based on the conversion result.

According to the aspect correction device having the above configuration,
The vertical direction correcting unit and the horizontal direction correcting unit respectively cause the liquid crystal display device to perform vertical thinning-out driving, so that the ratio of the number of scanning lines to the number of pixels in the liquid crystal display device and the number of scanning lines in the output signal from the solid-state imaging device are Match the ratio with the number of pixels. Thereby, the aspect ratio between the image read by the solid-state imaging device and the image displayed by the liquid crystal display device is
Will match. Therefore, if the aspect ratio is matched using this aspect correction device, even if the output signal is from a solid-state imaging device that reads an image with an aspect ratio different from that of the liquid crystal display device, the memory for correcting the aspect ratio is required. The display with the correct aspect ratio is performed on the liquid crystal display device without the need.

Further, the present invention provides a liquid crystal display device capable of performing a vertical thinning drive for thinning out and displaying a part of vertical scanning lines with a camera devised to achieve the above object. The liquid crystal display device includes a solid-state imaging device that reads an image at an aspect ratio different from that of the liquid crystal display device, and an aspect correction device that corrects the aspect ratio to display an output signal from the solid-state imaging device on the liquid crystal display device. Wherein the aspect correction device performs vertical thinning drive based on a ratio of the number of vertical scanning lines of the liquid crystal display device to the number of vertical scanning lines of the output signal. Means for converting the ratio of the number of horizontal pixels of the liquid crystal display device to the number of horizontal pixels of the output signal into the difference in the number of scanning lines, and performing the vertical thinning drive based on the conversion result. It is characterized in further comprising a horizontal direction correction means for.

In the camera having the above-described configuration, the aspect ratio of the image read by the solid-state imaging device by the aspect correction device and the image displayed by the liquid crystal display device match. Therefore, in this camera, even if the solid-state imaging device reads an image with an aspect ratio different from that of the liquid crystal display device, the image read by the solid-state imaging device does not require a memory for correcting the aspect ratio. Is displayed on the liquid crystal display device with a correct aspect ratio.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an aspect correction apparatus according to the present invention and a camera using the same will be described with reference to the drawings. FIG. 1 is an explanatory view showing an outline of an example of aspect correction according to the present invention, and FIG. 2 is a block diagram showing a main part of an aspect correction apparatus for performing the aspect correction.

In FIG. 2, this aspect correction device outputs an output signal from a CCD (not shown) to an LCD panel 1.
This is specifically applied to an electronic still camera equipped with an XGA class (800,000-pixel all-pixel reading system) CCD.

However, in an electronic still camera equipped with such an aspect correction device, the CCD side has an
The output signal from the CCD of 10,000 pixels and all pixels is
In order to perform display in accordance with the V standard, it is assumed that a thinning-out reading mode is performed at a reading stage of an output signal. The thinning-out reading mode here refers to, for example, a drive in which only one line is read out of three lines out of 768 lines, which is the number of lines in the vertical direction, and only a total of 256 lines are output.

On the other hand, as shown in FIG. 3, the LCD panel 1 has an effective area of 800 pixels in the horizontal direction and 225 lines in the vertical direction.
Degree) underscan. In other words, taking the vertical direction as an example, the NTSC system requires 242.5
While the lines are valid, this LCD panel 1 displays only 225 lines.

The LCD panel 1 has the N
In addition to the TSC system, the PAL system is also supported. That is, it is assumed that “vertical thinning-out drive” is possible in order to display an output signal of the PAL system in which 287.5 lines in the vertical direction are valid in 225 vertical lines corresponding to NTSC. For example, when an output signal of the PAL system is input, 287.5 lines are compressed to 242.5 lines by not displaying one line for every seven lines on the LCD panel 1.

In order to enable such vertical thinning drive, an LCD panel 1 is provided with an LCD as shown in FIG.
A driving timing generator (hereinafter, referred to as LCD-TG) 2 is connected. The LCD-TG 2 drives the LCD panel 1 by generating various timing signals including an enable (ENB) pulse and supplying the timing signal to the LCD panel 1. ENB pulse indicates ENB polarity,
DISENB polarity is for non-display. This E
The NB pulse allows the LCD panel 1 to perform vertical thinning-out drive, thereby enabling the aspect ratio of the image read by the CCD to be correctly displayed even with an output signal of the PAL system.

What has been described above is the structure generally used in an electronic still camera equipped with an XGA class CCD conventionally. The other components in FIG. 2, for example, the DRAM controller 3 and the RGB decoder 4 are the same as those in the related art, and the description thereof is omitted here.

However, the electronic still camera according to the present embodiment comprises a DRAM controller 3 and an RGB decoder 4
In that no image processing memory such as a VRAM is provided between them. Further, as described later, the output timing of the ENB pulse generated by the LCD-TG2, that is, the control of the vertical thinning drive by the LCD-TG2 is different from the conventional one.

Here, an example of the processing operation when the output signal from the XGA class CCD is displayed on the LCD panel 1 in the electronic still camera configured as above will be described with reference to FIG.

As described above, the XGA class CCD has an effective pixel ratio that is not the same as the effective ratio defined by the TV standard, the horizontal effective ratio is lower than the TV standard, and the vertical effective ratio is opposite. It is higher than the TV standard. For this reason, when the CCD captures the image shown in FIG. 1A and displays the CCD output on the LCD panel 1 as it is, the displayed image is in the vertical direction (V direction).
5.57% stretched in the horizontal direction (H direction)
The image is compressed by 1.73%, resulting in a vertically long image as a whole as shown in FIG. In other words, the CCD of the 800,000-pixel all-pixel reading system is read by the NTSC standard of horizontal synchronization 15.734KHz and vertical synchronization 60Hz,
When signal processing is performed using this synchronization signal cycle and displayed on the LCD panel 1, the image reflected on the LCD panel 1 has a vertical distortion of 5.57% and a horizontal distortion of 1.73%. As a result, the aspect ratio of 4: 3 becomes out of order.

Therefore, in this electronic still camera, CC
When displaying the D output on the LCD panel 1, aspect correction is performed. First, the LCD-TG2 performs vertical thinning drive to compress 5.57% of vertical distortion by LC.
Instruct D panel 1. That is, the LCD-TG2 has C
When the CD is in the thinning-out reading mode, the output in the vertical direction becomes 256 lines. To fit this into 242.5 lines effective in the NTSC system, as shown in FIG. Thin out lines. This is 1
This is the ratio of thinning out one line to nine lines. Therefore, L
In CD-TG2, the polarity of the ENB pulse is 1 in 19 lines.
An ENB pulse is generated so as to have a DISENB polarity at a line ratio, and this is applied to the LCD panel 1.

Although the horizontal direction is compressed by 1.73%, this electronic still camera does not include an image processing memory such as a VRAM, so that the horizontal correction using the image processing memory, that is, the horizontal correction is performed. Performs vertical compression by an amount corresponding to 1.73% compression without stretching in the direction. That is, the LCD-TG 2 thins out 4.2 lines (242.5 lines × 1.73%) for horizontal correction in addition to the above-described 13.5 lines in the vertical direction, and as a result, performs vertical thinning drive for 17.7 lines. LCD
Display on panel 1 is performed. This is one in 14 lines in total
Since the line is thinned out, the polarity of the ENB pulse is
What is necessary is to make DISENB polarity at a ratio of one line to 14 lines.

However, even if such correction is made, NT
The output signal displayed for the SC effective horizontal period is
1.73% less does not improve. However, the LCD panel 1 considers a certain degree of underscan for the effective area of the NTSC system, so if a non-display area of 1.73% is included in the underscan,
1.73% less output signal is not a problem. In order to realize this, the horizontal drive start timing pulse generated by the LCD-TG 2 may be adjusted to an appropriate position so that the non-display area is hidden by the underscan area.

As described above, according to the electronic still camera (aspect correction device) in the present embodiment, the LCD
The panel 1 uses the conventional vertical thinning drive function to support the PAL system, and compresses 5.57% of the vertical distortion and further expands the horizontal distortion of 1.73% by using the function. Compression in the vertical direction is performed by an amount corresponding to the horizontal distortion, and correction in both the vertical and horizontal directions (aspect correction) is performed.

Therefore, by using this electronic still camera, the aspect ratio can be corrected without requiring an expensive image processing memory such as a VRAM.
The configuration for displaying the CCD output on the LCD panel 1 is not complicated, and the cost can be suppressed.

Also, if this electronic still camera is used,
As the aspect ratio can be corrected simply by changing the thinning rate of the existing vertical thinning drive,
Existing LCD panels 1 and the like can be used. That is, the aspect ratio can be corrected only by changing the logic of the ENB pulse and the drive start timing pulse of the LCD-TG2.

Although the present embodiment has been described with reference to an example in which an output signal from an XGA class CCD is displayed on the LCD panel 1, the present invention is not limited to this. For example, the present invention can be applied to other types of CCD as long as the effective pixel ratio is different from the effective ratio defined by the TV standard. However, the aspect ratio can be corrected by using the present invention because the image before correction is vertically distorted in the vertical direction, and in the horizontal direction, only compression distortion equal to or less than the underscan on the LCD panel occurs. Case.

[0029]

As described above, in the aspect correction device and the camera using the same according to the present invention, the ratio between the number of scanning lines and the number of pixels in the liquid crystal display device and the solid-state imaging device are utilized by utilizing the vertical thinning drive. The ratio between the number of scanning lines and the number of pixels in the output signal from the device is made to match. Therefore, if the aspect ratios are matched in this way, even for an output signal from a solid-state imaging device that reads an image at an aspect ratio different from that of a liquid crystal display device, a memory for correcting the aspect ratio is required. Therefore, the display with the correct aspect ratio is performed on the liquid crystal display device, so that the configuration for displaying the output signal from the solid-state imaging device on the liquid crystal display device becomes complicated, and the configuration is high. There is no cost increase.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory diagrams showing an outline of an example of an embodiment of aspect correction according to the present invention, wherein FIG. 1A is a diagram showing a CCD output image, and FIG.
FIG. 7C is a diagram showing a case where the image is displayed, FIG. 7C is a diagram showing a case where the image is displayed on the LCD after V correction, and FIG.

FIG. 2 is a block diagram showing a main part of an example of an aspect correction device according to the present invention.

FIG. 3 is an explanatory diagram illustrating a pixel structure of an example of an LCD panel.

4A and 4B are explanatory diagrams showing a comparison between an effective pixel ratio of a CCD and an effective ratio of a TV standard, wherein FIG. 4A shows a case of an NTSC video camera, and FIG. 4B shows a PAL video camera; FIG. 4C shows a case, and FIG.
FIG. 2 is a diagram illustrating a case of an electronic still camera using a CCD of a class.

FIG. 5 is an explanatory diagram showing a comparison between an effective pixel ratio of an XGA class CCD and an effective ratio of a TV standard.

[Explanation of symbols]

 1. LCD panel, 2. LCD-TG

Claims (2)

[Claims] 1. A solid-state imaging device for reading an image at an aspect ratio different from that of a liquid crystal display device using a liquid crystal display device capable of performing vertical thinning drive for thinning out and displaying a part of vertical scanning lines. An aspect correction device for displaying an output signal from the device, wherein the vertical thinning drive is performed based on a ratio of the number of vertical scanning lines of the liquid crystal display device to the number of vertical scanning lines of the output signal. Vertical direction correction means to be performed, a ratio of the number of horizontal pixels of the liquid crystal display device to the number of horizontal pixels of the output signal is converted into a difference in the number of scanning lines,
An aspect correction device comprising: a horizontal direction correction unit for performing the vertical thinning drive based on the conversion result. 2. A liquid crystal display device capable of performing a vertical thinning drive for displaying a display by thinning a part of a vertical scanning line, and a solid-state imaging device that reads an image at an aspect ratio different from that of the liquid crystal display device. A camera comprising: an aspect correction device that corrects the aspect ratio so that an output signal from the solid-state imaging device is displayed on the liquid crystal display device. Vertical correction means for performing the vertical thinning drive based on the ratio between the number of scanning lines in the direction and the number of scanning lines in the vertical direction of the output signal, and the number of pixels in the horizontal direction of the liquid crystal display device and the output signal. Convert the ratio of the number of pixels in the horizontal direction to the difference in the number of scanning lines,
A camera using an aspect correction device, comprising: a horizontal direction correction unit for performing the vertical thinning drive based on the conversion result.