JPS61113361A - Picture image pickup device - Google Patents

Abstract

PURPOSE:To provide optional gradation characteristics by driving selectively a display cell in a time applied with weighting to correct uneven exposure at a position on a photosensitive sheet corresponding to each display cell to eliminate density unevenness to an picked-up picture. CONSTITUTION:The lightness level of a video signal from an image reproducing processor 1 is converted sequentially into stages of digital signals by an A/D converter 9 and written on an RAM11. A CPU13 applies a weighted correction processing correcting unevenness of exposure on a position of a photosensitive sheet corresponding to each display cell to a video signal versus drive time data group. The CPU13 reads sequentially the corrected drive time data group as a display command, gives it to an LCD controller 8 which drives selectively a liquid crystal module 7 for display control.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image photographing device for photographing an image displayed on a flat panel display device onto a photosensitive sheet (film).

1. Prior Art 1. As is well known, is image photography in which a reproduced image obtained by computer tomography (CT) or the like is photographed on a photosensitive sheet? In order to reproduce the digital γ signal, the C
An RT display device is used. However, this CRT display device has drawbacks such as a large external size (depth dimension), an inability to fully correct image distortion, easy influence by magnetic lines of force, and poor density resolution. There will be uneven brightness in the photographed image due to lower brightness, uneven luminance of the phosphor, uneven coating, and lower peripheral brightness at COS θ due to shooting through a rough optical lens. I ran into problems. For this reason, at present, an image I using a flat panel display device based on dotbuttrix display as an image display means has been developed.
A tfji shadow device is being considered. This flat panel display device consists of display cells such as a liquid crystal display, a gas discharge display, and an LED display arranged in a range from C11 to Cnm as shown in Fig. An image is displayed by selectively driving cells C11 to Cn. An example of an image capturing device using this flat display device is as shown in FIG.
An image reproduction processing device l such as a peep calculator gives a display cell row selection signal and a selection signal to the flat panel display device 2 according to the displayed image, and displays the image on the flat panel display device M2. The front image is formed on the photosensitive sheet 4i through the optical lens 3, and is photographed on the photosensitive sheet 4i by operating the camera 5 (see Japanese Utility Model Application No. 57-7H45).

Therefore, in such an image capturing device, CR
It is possible to take pictures without the disadvantages of the T display device, such as the aforementioned image distortion and the influence of magnetic lines of force, but like the CRT display device, there is a decrease in peripheral brightness due to shooting through an optical lens and a decrease in the brightness of the display cell. There is a problem in that uneven brightness occurs in the photographed image due to variations and even uneven illumination due to the light source. In addition, with on-off control of display cells, it is not possible to express the gradation level corresponding to the video signal.
There was a problem in that it was impossible to obtain photographed images with good density resolution.

OBJECTS OF THE INVENTION In view of the problems described below, an object of the invention is to eliminate density unevenness in photographed images by using a flat display device having an on-C7R drive display cell,・An object of the present invention is to provide an image photographing device capable of maintaining the WJ timing characteristics of j.

-Structure of the Invention- In order to achieve this object, the present invention has a flat panel display device which displays an image by a plurality of display cells arranged 6 and selectively driving them. In an image capturing device that photographs a display image of the device by exposing it to a photosensitive sheet, each display cell is measured at a time weighted to correct unevenness in exposure amount at a position on the photosensitive sheet corresponding to each display cell. This is a proposal to drive selection.

Furthermore, the present invention selects a display cell at a time corresponding to the brightness level of the video signal and at a time weighted to correct unevenness in exposure amount at a position on the photosensitive sheet corresponding to each display cell. This is what we propose to drive.

- Embodiments - Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 5.

FIG. 1 shows a main block 1Δ of a control device when a liquid crystal display device is used as a flat panel display device. Control device 6
receives input of a display image video signal No. 11 and horizontal and vertical synchronizing signals from an image reproduction processing device 1 such as a computer tomography, and transmits a display image to a liquid crystal module 7 in which display cells are arranged in a dot matrix, according to the video signal. Outputs selection drive output for each display cell for image display. Further, the control device 6 has a microcomputer as a control center, and L
The CD controller 8 also outputs row selection drive and column selection drive signals for the liquid crystal module 7.

The video signal from the image reproduction processing device 1 is converted into a digital signal by an A/D 1% unit 9 at its brightness level or slice (electronization) level in n stages.

Further, the horizontal and vertical synchronizing signals from the image reproduction processing device 1 are given to the address as data through the RAM 10, and the complaint and vertical synchronizing signals are used as the address to write to the RAM.
11, video signal slice data that has passed through the A/'D converter 9 is sequentially written. This data speed is, for example, °
CPU based on program data in ROM12
13 years ago under the direction of DM A Ji. The conversion from hidden 7r4 words to digital signals in the A/D converter 9 requires 5 brightness levels of the video signal ←
Accordingly, each display section of the liquid crystal module 7 is associated with tl-selective drive time.

To explain an example of quantization, as shown in Fig. 2, a video signal of one water synchronization signal period is digitized with a slice level t up to 1n, and the corresponding display cell is digitized according to each slice level 1n. As shown in Fig. 3, the driving time is T
The driving time for the answer display cell can be determined by performing an A/D converter that corresponds to the binary number /16 of the digital signal so that the result is 1-Tn. The correspondence relationship between this bidet No. 1a level and the driving time T1 to Tn is as follows.
In addition to linear characteristics, various compression and expansion characteristics may be provided depending on the density characteristics of the photosensitive sheet, for example.

Returning to FIG. 1, the CPU 13 weights the video signal vs. drive time data group stored in the RAM 1l to correct unevenness in exposure amount at the position of the photosensitive sheet 2 corresponding to each display cell. Perform correction processing. In other words, this correction process corrects the unevenness of exposure at the surface position of the photosensitive sheet 1 due to a decrease in the peripheral exposure of the photographed image due to passing through the optical lens 3, variations in the brightness of each display cell, uneven illumination due to the position of the light source, etc. Something to correct.

The correction coefficients associated with each display cell are stored in the ROM12 or RA.
Store it in MII as a table 1, for example, CPU1
In step 3, the actual driving time data group can be obtained by multiplying the driving time data group by a corresponding correction coefficient.With this correction, the driving time can be changed from T'1 to T' according to the slice level.
nt, two bolts are drawn.

The CPU 13 sequentially reads out the drive time data group corrected for unevenness in exposure amount using the exposure start signal of the exposure switch 14 as a display command, and sends it to the LCD controller 8 along with horizontal and vertical synchronizing signals (count/t data). Provided in synchronization with horizontal and vertical signals. This allows the LCD
The controller 8 selectively drives each display cell of the liquid crystal module 7 and performs display control for a time corresponding to the driving time data. This display control varies depending on the driving method of the liquid crystal module 7, but for example, A sword that can preset driving time data for line selection
j.

This is realized by attaching a counter and operating a timer that obtains a driving output only during the counting operation each time the display cell is switched.

FIG. 4 illustrates a display image obtained by display control according to this embodiment. That is, among the display cells C11''Cnm of the liquid crystal monoyl 7, the display cells CIl to C in the first column
nl is driven for the shortest time T to reach the first slice level, and green is also displayed with low brightness, and display cells C1l to Cr1m in the m-th column are driven for the longest time T to reach the m-th slice level. By driving 'l, the display with the highest brightness is achieved, and the first to nth columns are sequentially driven for a driving time of T'2 to T'.
A state in which the length is increased to n-1 is shown. As is clear from this display image, by changing the driving time of each display cell according to the brightness level of the bidet No. 1g, the brightness of a flat display device having display cells driven on and off can be adjusted. This makes it possible to take pictures with the gradation characteristics of the photosensitive sheet depending on the video signal. In addition, a drive time correction that corrects the unevenness of exposure at the position of the photosensitive sheet corresponding to each display cell makes it possible to take images without unevenness in brightness. .

Note that exposure unevenness correction is not limited to correcting the time according to the brightness level of the video signal; it also applies to conventional flat panel displays. It goes without saying that the same effects can be obtained by applying the present invention to an image capturing apparatus using a camera.

Further, the fog light unevenness correction according to the present invention makes it easy to obtain high-quality photographed images for configuring an image photographing device that photographs in multiple formats. That is, the conventional multiformant imaging device has a CR as shown in FIG.
A device that integrates the T display device 2I and the optical lens 22,
Although it is a complicated and expensive device that moves the photosensitive film 23 in the X and Y directions according to the exposure position, in the case of a flat panel display device that corrects exposure unevenness based on the present invention, the device shown in FIG. 5(B) is used. As shown in the figure, a plurality of optical lenses 25 each having a different angle are provided for one flat display device 24, and a plurality of images are taken on the photosensitive sheet 2B by switching the optical lenses 25. This can be easily corrected by the individual difference t due to the degree of decrease in peripheral light amount of the optical lens, etc., and by individual exposure unevenness correction on the display control device side.

Furthermore, the exposure unevenness correction according to the present invention makes it possible to use an optical lens with a short focal length, thereby making it possible to downsize the apparatus. In other words, with an optical lens that has a short focusing distance, the amount of peripheral light decreases significantly, making it difficult to obtain high quality images with conventional devices, but with the present invention, the amount of exposure can be corrected without deteriorating image quality. , an optical lens with a short focal length can be used. In this case, since image distortion when using a lens with a short focal length can be corrected by changing the address when reading data, high image quality can be obtained by this correction.

Effects of the Invention As is clear from the above description, according to the present invention, the photosensitive sheet can be reduced due to variations in the light emission of each display cell of a flat panel display device, a decrease in the amount of peripheral light of an optical lens, uneven illumination, etc. It becomes possible to take pictures without exposure unevenness, and in combination with display cell driving time control according to the brightness level of the video signal, it is possible to obtain high-quality photographed images.

[Brief explanation of the drawing]

:iSf diagram is a block configuration diagram of the image capturing device according to the present invention; FIG. 2 is an explanatory diagram of slice levels for video signals according to the present invention; FIG. 3 is a diagram illustrating driving time for slice levels according to the present invention; FIG. 4 is a diagram showing an image display pattern with gradation characteristics according to the present invention, and FIG.
5(B) is a configuration diagram of a multi-format photographing device according to the present invention, FIG. 6 is a display cell layout diagram of a flat panel display device, and FIG. 7 is a diagram of a conventional flat panel display device.
FIG. 1 is a configuration diagram of an image capturing device. ■... Image reproduction processing device, 3... Optical lens, 4... Photosensitive sheet. 5... Nyatsuta 1 6... Control device, 7... Liquid crystal module, 8... LCD controller, 9... A/D converter, lO... Address bus, 11... RAM. I2...ROM, 13...CPU, 14...Exposure switch, 24...Flat type display device, 25...Optical lens, 26...Photosensitive sheet, ! 6... data.

Claims (1)

[Claims] i) An image photographing device which has a flat display device in which a plurality of display cells are arranged in a dot matrix and displays an image by selectively driving them, and which photographs the displayed image of the flat display device by exposing a photosensitive sheet. An image photographing device comprising: display control means for selectively driving a display cell at a time weighted to correct unevenness in exposure amount at a position on a photosensitive sheet corresponding to each display cell.