JP2520936B2 - CRT image printing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a CRT image printing method for printing a color image having a shade on a color photographic paper using a monochrome CRT and a color filter.

[Conventional technology]

There is known a CRT image printing apparatus which prints a color image on a color printing paper with three exposures by using a monochrome CRT, a red filter, a green filter and a blue filter. In this CRT image printing device, three-color images are sequentially displayed in black and white.For example, when a black and white image corresponding to a red image is displayed on the black and white CRT, a red filter is inserted in the optical path to convert the black and white image into a red image. Then, when a black-and-white image corresponding to the green image is displayed on the black-and-white CRT, a green filter is inserted into the optical path to convert the black-and-white image to a green image and then printed on the color photographic paper.
Finally, when a black-and-white image corresponding to a blue image is displayed, a blue filter is inserted into the optical path and the converted blue image is printed on color photographic paper.

[Problems to be Solved by the Invention]

However, when exposing a general CRT image to color photographic paper, the CR in the red wavelength region is low, so CR
It takes a long time to print a red image on the T-image printing device. In particular, since the portion exposed to a large amount of red is often black, it takes a long time to print an image including a large amount of this black portion. Moreover, the above tendency becomes remarkable when the exposure amount is controlled by the exposure time with the CRT beam brightness kept constant.

The present invention has been made to solve the above problems, and an object thereof is to provide a CRT image printing method capable of shortening the exposure time.

[Means for solving the problem]

In order to solve the above problems, the present invention is obtained by extracting a yellow signal (y) or a magenta signal (m) from a red signal (R), a green signal (G) and a blue signal (B) of each pixel. The four types of color signals (one of y, m and r, g, b) are sequentially sent to the black and white CRT to display the image of each color in black and white, and a single color is used by using the color filter corresponding to each color. It is converted into an image and a color image of one screen is printed on a color photographic paper by four exposures. Another invention is to extract a yellow signal (y) and a magenta signal (m) from a red signal (R), a green signal (G) and a blue signal (B) of each pixel, and obtain five types of obtained signals. Color signal (y, m, r, g,
b) is sequentially sent to a black and white CRT to display each color image in black and white, and a color filter corresponding to each color is used to convert it into a single color image, and one screen of color image is converted to color photographic paper with 5 exposures. It was burned.

As a color filter, a yellow filter and / or a magenta filter is provided at a position divided into four or more in the circumferential direction,
It is preferable to use a filter turret equipped with a red filter, a green filter and a blue filter.

[Action]

In the present invention, instead of the conventional three-color additive normal surface exposure with each color of red, blue, and green, four or more additive color normal surface exposures with yellow exposure and / or magenta exposure are used. As a result, a yellow filter is used for a portion that can be exposed to red simultaneously with green, and a magenta filter is used for a portion that can be exposed to red simultaneously with blue.
The red light emitted from the CRT can be effectively used. Therefore, the exposure time can be shortened.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1 showing a CRT image printing apparatus embodying the present invention, a video player, a TV camera and the like are used as the image input apparatus. In this embodiment, a color TV camera 10 is used, and an original image is used by the camera 10. Alternatively, the subject is imaged and a video signal is output. In addition, instead of a color TV camera,
The resolution may be improved by capturing an image with a monochrome TV camera having a three-color filter.

The video signal is separated into a red signal R, a green signal G and a blue signal B by a decoder 11, and then sent to an A / D converter 12 where it is converted into a digital signal. The digital signal is inversely logarithmically converted by the logarithmic converter 13, converted into density values by the logarithmic converter 13, and then sent to the color correction circuit 14. The logarithmic converter 13 is a positive / negative converter or a negative / negative converter.
Since positive conversion is performed, it is necessary to perform normal logarithmic conversion when capturing a negative image. The color correction circuit 14 corrects the difference in the spectral characteristics between the color TV camera 10 and the color photographic paper by using a predetermined arithmetic expression. The color-corrected three-color signals R, G, B are sent to the gradation correction circuit 15 where they are gradation-converted so as to correspond to the gradation characteristics of the color photographic paper.

The color-corrected and tone-converted three-color signals R, G, B are stored in the frame memories 16a to 16c provided for each color. Color signals stored in each of the frame memories 16a to 16c
R, G, B are read out for each pixel and sent to the arithmetic circuit 17, where the red signal R and the green signal G overlap (yellow component), and the red signal R and the blue signal B overlap. The portion (magenta component) is extracted. Then, the yellow component and the magenta component are subtracted from each color signal (R, G, B). By this calculation, a yellow signal y, a magenta signal m, a red signal r, a green signal g, and a blue signal b are formed,
The obtained color signals (y, m, r, g, b) are written in the frame memories 18a to 18e provided for each color.

The five color signals (y, m, r, g, b) of each pixel written in the frame memories 18a to 18e are sequentially read out for each color and D
After being converted into an analog signal by the / A converter 19, the driver
Sent to 20. The driver 20 drives the monochrome CRT 21 to generate a monochrome image based on a blue signal, that is, a monochrome image corresponding to the density of a blue image, a monochrome image corresponding to the density of a magenta image, and a monochrome image corresponding to the density of a red image, A black-and-white image corresponding to the density of the yellow image and a black-and-white image corresponding to the density of the green image are sequentially displayed for a predetermined time. The order of this display can be arbitrarily determined.

The black-and-white image displayed on the black-and-white CRT 21 is imaged on the color photographic paper 24 at a desired magnification by the lens 23. Between the lens 23 and the color photographic paper 24, the blue filter 2
5, a magenta filter 26, a red filter 27, a yellow filter 28, and a green filter 29 are arranged in a circumferential direction at equal pitches, and a shutter 31 is provided. Filter Turret 30
A pulse motor 33, which is rotated via a driver 32 based on a signal from a controller 41, rotates a predetermined angle.
As a result, the desired color filter is positioned on the printing optical path 35. The shutter 31 is driven by the shutter drive unit 34.

The color printing paper 24 is wound around a supply reel 36, drawn out frame by frame by a drawing roller 38 rotated by a motor 37, and sent to an exposure position formed under a mask 39, where it is fed five times. It is exposed and the color image is printed as a latent image. This exposed frame is the take-up reel
It is wrapped around 40, developed and then cut into individual frames.

The A / D converter 12 to the gradation correction circuit 15, the D / A converter 19,
It is provided for each color, and the logarithmic converter 13
The data, the coefficients and constants of the arithmetic expression of the color correction circuit 14, and the data of the gradation correction circuit 15 are selected from a large number of data stored in the controller 41 and written. The controller 41 is composed of a microcomputer, and controls each part in sequence.

The arithmetic circuit 17 is composed of a microcomputer and performs arithmetic operations in the following procedure. First, two color signals of the same pixel, for example, (R, B) are read from the frame memories 16a to 16c, and the overlapping portion of the red signal R and the blue signal B is detected. That is, a predetermined value of the red signal R and the blue signal B is detected, and this value is the magenta signal m.
Becomes Next, the magenta signal m is subtracted from the red signal R and the blue signal B, respectively, and the red signal r ′ and the blue signal b are subtracted.
Is calculated.

Next, the color signals (r ', G) of the same pixel are read out, and the overlapping portion of the red signal r'and the green signal G is detected.
That is, a predetermined value of the red signal r'and the green signal G is detected, and this value becomes the yellow signal y. Next, the yellow signal y is subtracted from the red signal r ′ and the green signal G, and the red signal r and the green signal g are calculated.

FIG. 2 shows a baked state, and the operation of the apparatus shown in FIG. 1 will be briefly described with reference to this. The video signal output from the color TV camera 10 is decoded by the decoder.
After being separated into 3 color signals (R, G, B) at 11, A / D conversion, logarithmic conversion, color correction, gradation correction, and then 5 color signals (y, m, r, g, b) After being converted, they are stored in the frame memories 18a to 18e provided for each color.

The five color signals (y, m, r, g, b) stored in the frame memories 18a to 18e are sequentially read out for each color. That is, first, the blue signal b for one frame stored in the frame memory 18a is sequentially read out for each pixel, converted into an analog signal, and then sent to the driver 20. This driver 20 drives the monochrome CRT 21 to display a blue image for a predetermined time T1. At this time, the blue filter 25 of the filter turret 30 is inserted in the optical path 35. Black and white CRT21
When a blue image is displayed on the shutter 31, the shutter 31 is opened for a predetermined time T2 calculated by the controller 41, for example, one second. While this shutter 31 is open, the black and white CRT2
The blue image displayed in 1 is printed on the color photographic paper 24. This blue image is developed by color photographic paper 24,
It develops yellow.

When the blue exposure is completed, the magenta signal m stored in the frame memory 18b is read out and displayed on the monochrome CRT 21. At the same time, since the magenta filter 26 is inserted into the optical path 35 by rotating the filter turret 30 by a predetermined angle, the monochrome image displayed on the monochrome CRT 21 is converted into a magenta image. In this state, since the shutter 31 is opened for the predetermined time T3 calculated by the controller 41, the magenta image is printed on the color photographic paper 24. This magenta image develops yellow and cyan by the development of the color printing paper 24 to form green.

When the magenta exposure is completed, the frame memory 18c
The red signal r stored in is read out and displayed on the black and white CRT 21. At the same time, the filter turret 30 rotates by a predetermined angle and the red filter 27 is inserted into the optical path 35, so that the monochrome image displayed on the monochrome CRT 21 is converted into a red image. In this state, since the shutter 31 is opened for a predetermined time T4, the red image is printed on the color photographic paper 24.
The red image is developed into cyan by developing the color photographic paper 24.

When the red exposure is completed, the yellow signal y stored in the frame memory 18d is read out and displayed on the monochrome CRT 21. Along with this, the yellow filter 28 has an optical path 35.
The black-and-white image displayed on the black-and-white CRT 21 is converted into a yellow image because it is inserted into. In this state, the shutter 31 is opened for the predetermined time T5, so that the yellow image is printed on the color printing paper 24. This yellow image forms a blue color by developing magenta and cyan by the development of the color photographic paper 24.

When the yellow exposure is completed, the frame memory 18e
The green signal g stored in is read out and displayed on the monochrome CRT 21. At the same time, since the green filter 29 is inserted, the monochrome image displayed on the monochrome CRT 21 is converted into a green image. In this state, since the shutter 31 is opened for a predetermined time T6, the green image is printed on the color printing paper 24. The green image develops magenta by developing the color photographic paper 24.

A color image of one screen is printed on the color printing paper 24 by five times of exposure. After the printing, the motor 37 rotates to pull out the unexposed portion of the color printing paper 24 from the supply reel 36, and wind the exposed portion on the take-up reel 40.

〔The invention's effect〕

As described in detail above, according to the present invention, in addition to conventional red exposure, green exposure, and blue exposure, yellow exposure,
Since the exposure including the red component such as magenta exposure is performed, the red component dispersed from the black and white CRT can be effectively used. That is, in the present invention, by adding the yellow exposure or the magenta exposure, the red exposure is performed at the same time as the green or blue exposure, so that the red exposure time can be shortened, and the overall exposure time can be shortened. Particularly, a better effect can be obtained when the exposure amount is controlled by the exposure time with the CRT beam brightness kept constant.

Further, by using a four-color or five-color filter turret in which yellow and / or magenta filters are arranged in addition to the three-color filter, it becomes possible to easily perform the exposure of four or more colors.

[Brief description of drawings]

FIG. 1 is a block diagram showing a CRT image printing apparatus embodying the present invention. FIG. 2 is a timing chart of FIG. 1 showing a baked state. 21 …… B / W CRT 24 …… Color photographic paper 25 …… Blue filter 26 …… Magenta filter 27 …… Red filter 28 …… Yellow filter 29 …… Green filter 30 …… Filter turret 31 …… Shutter.

Continuation of the front page (56) Reference JP-A-59-219088 (JP, A) JP-A-62-86349 (JP, A) JP-A-62-9341 (JP, A) JP-A-62-141855 (JP , A) JP 61-276493 (JP, A) JP 63-101838 (JP, A) Actual opening 61-198942 (JP, U) Actual opening 62-6734 (JP, U) Actual opening 63-43136 (JP, U) Actually opened 62-98387 (JP, U) Actually opened 62-121888 (JP, U) Japanese public 63-67174 (JP, B2) Japanese public 5-21474 (JP, Japanese) B2) Japanese Patent Publication 6-25848 (JP, B2) Japanese Patent Publication 6-64305 (JP, B2) Japanese Publication 6-25847 (JP, B2) Japanese Publication 6-32456 (JP, B2) Japanese Publication 5 -21475 (JP, B2) Japanese Patent Publication 7-56559 (JP, B2)

Claims (3)

(57) [Claims] 1. Four kinds of color signals obtained by extracting a yellow signal (y) or a magenta signal (m) from a red signal (R), a green signal (G) and a blue signal (B) of each pixel. (One of y, m and r, g, b) is sent to the black and white CRT sequentially, the image of each color is displayed in black and white, and the color filter corresponding to each color is used to convert to a single color image. A CRT image printing method characterized in that a single-screen color image is printed on color photographic paper with one exposure. 2. Five kinds of color signals obtained by extracting a yellow signal (y) and a magenta signal (m) from a red signal (R), a green signal (G) and a blue signal (B) of each pixel. (Y, m, r, g, b) are sent to a black and white CRT in order to display each color image in black and white, and a color filter corresponding to each color is used to convert to a single color image, and 1 A CRT image printing method, characterized in that the color image on the screen is printed on color photographic paper. 3. A color turret in which a yellow filter and / or a magenta filter, a red filter, a green filter, and a blue filter are attached at circumferentially divided positions as the color filter. The CRT image printing method according to claim 1 or 2.