JPH01114836A - Exposing device - Google Patents

Abstract

PURPOSE:To expose an image of any gradation on a photosensitive material by a simple construction by exposing the photosensitive material with lighting beams from a cathode ray tube. CONSTITUTION:The title device is provided with a time modulation means 13 varying pulse width according to the level of input video signals, and the cathode ray tube 16 emitting light of fixed brightness at the timing of pulse signals subjected to time modulation. According to the level of the video signal, the light emitting time of the cathode ray tube 16 is controlled, and the area of the photosensitive material 1 on which light is projected varies in accordance with the level. Ultmately, excellent exposure is performed to correspond with the gradation of videos projected on the photosensitive material 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exposure apparatus using a cathode ray tube as an exposure source, which is suitable for a printer using a photosensitive material such as a sheet having a photosensitive capsule.

[Summary of the invention]

The present invention provides an exposure apparatus using a cathode ray tube as an exposure source suitable for a printer using a photosensitive material such as a sheet having a photosensitive capsule. A cathode ray tube is provided to which the pulse signal outputted by the time modulating means is supplied and emits light at a constant brightness for a time corresponding to the pulse signal, and the photosensitive material is exposed to light irradiated by the cathode ray tube. Any Ill style ii with a simpler configuration! j image can be exposed onto a photosensitive material.

[Conventional technology]

Conventionally, a method of printing color images on printing paper using photosensitive capsules has been proposed (Japanese Patent Laid-Open No. 59-3
0537, etc.), this printing method, as shown in FIG. 7, prints a plurality of yellow, magenta, and cyan microcapsules (2Y
), (2M), and (2C) are uniformly coated to form microcapsules (2), which is a photosensitive sheet called microcapsule sheet full. These yellow, magenta, and cyan microcapsules (2Y),
(2M) +, (2C) Precursors of pigments such as photochromic dyes, electrochromic dyes, and leuco dyes are contained inside a relatively soft outer shell made of foam, polyvinyl alcohol, gum arabic, etc. A substance containing a substance (or pigment) and a photocurable composition containing an ethylenically unsaturated compound, etc. is encapsulated, and when irradiated with light of a specific wavelength, the photocurable composition hardens to form microcapsules. Microcapsules (2Y) containing a yellow pigment precursor harden when irradiated with blue light, and microcapsules containing a magenta pigment precursor harden when irradiated with green light. The capsule (2M) is cured, and the microcapsule (2c) containing a cyan dye precursor is cured by irradiation with red light.

Then, as shown in FIG. 8, the microcapsule sheet (1) constructed in this way is irradiated with image light of a color image to be printed. This image light irradiation is performed by separating the color image light into three primary colors and dividing it into red image light irradiation, green image light irradiation, and blue image light irradiation, and the microcapsules hardened by the irradiation with each image light. (2a) is formed. Then, as shown in FIG.
) are brought into contact with each other, and rollers (4a) and (4b) are used to apply pressure between this sheet)-(1) and the color developer IE (31).By applying pressure in this way, the corresponding wavelengths are Microcapsules (2Y) and (2M) that are not irradiated with light and are not cured.

The outer shell of (2C) is destroyed and the substance containing the dye precursor inside is transferred to the surface of the color developing paper (3). This developer paper (3
), the surface of the developing paper (3) develops the corresponding colors (yellow, magenta, cyan), and the mixture of these three colors creates a color image. A color image is printed on this color developing paper (3).

[Problem that the invention seeks to solve]

By the way, when exposing the microcapsule sheet (1) having the microcapsule layer (2) configured in this way with image light, a high-intensity light source used for projectors is used as the exposure source. It is common to use a monochromatic cathode ray tube, and to expose an image displayed on the display surface of the cathode ray tube.

The gradation (brightness and darkness) of the image reproduced by exposing the sheet to light is changed by changing the luminance of the image displayed on the cathode ray tube. However, there is a problem in that it is difficult to sufficiently change the gradation of an exposed image simply by changing the luminance of the cathode ray tube. In other words, the level of the signal supplied to the electron gun of the cathode ray tube must be changed with sufficient linearity up to high frequencies in accordance with the gradation, but this requires a complex circuit configuration and a large number of components. This has the disadvantage of requiring expensive elements.

In order to solve these problems, the present applicant previously proposed an exposure device that changes the gradation of the exposed image by changing the spot diameter of the electron beam of the cathode ray tube (Japanese Patent Application No. 62-85).
No. 081). However, there has been a demand for a structure that allows for finer gradation changes with a simpler configuration.

In view of the above, an object of the present invention is to provide an exposure apparatus that can expose an image of a predetermined gradation with a simple configuration.

[Means for Solving the Problems] As shown in FIG. 1, for example, the exposure apparatus of the present invention includes a time modulation means (13) that changes the pulse width according to the level of an input video signal, and this time modulation means. The cathode ray tube (16) is supplied with a pulse signal output from the cathode ray tube (13) and emits light at a constant brightness for a time corresponding to the pulse signal. ) is exposed to light.

[Effect]

According to the exposure apparatus of the present invention, since the emission time of the cathode ray tube is controlled according to the level of the video signal, the irradiation area of the light-sensitive material (1) changes according to the level, and due to the change in the irradiation area. Good exposure can be performed in accordance with the gradation of the image irradiated onto the photosensitive material (1).

〔Example〕

Hereinafter, one embodiment of the exposure apparatus of the present invention will be described with reference to FIGS. 1 to 4. In these figures 1 to 4,
Components corresponding to those in FIGS. 7 to 9 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

This example is an exposure device that exposes a microcapsule sheet +11, which is a photosensitive material containing microcapsules M(2) as described above. In FIG. 1, (11) indicates a video signal input terminal; 11), a luminance signal of a video signal of a still image to be exposed is supplied. The luminance signal obtained at this input terminal (11) is then sent to an amplifier (12).
is supplied to the non-inverting input terminal of the comparator (13). Further, (14) indicates a comparison signal input terminal to which a sawtooth wave as shown in FIG.
Supplied to the inverting input terminal of In addition, in this example, 1000
Pixels constitute one horizontal scanning line.

The comparator (13) compares the level of the luminance signal obtained at the non-inverting input terminal with the level of the sawtooth wave obtained at the inverting input terminal, and goes high when the level of the luminance signal is higher than the sawtooth wave. Outputs a level signal “H” and outputs a low level signal “L” when the sawtooth wave level is higher than the luminance signal
Output.

The output signal of this comparator (13) is then input to the amplifier (1
5) to the cathode or grid of the electron gun of the cathode ray tube (16).

By supplying the signal to the cathode ray tube (16) in this way, when the comparator (13) is outputting a high level signal "H", the electron beam from the electron gun of the cathode ray tube (16) causes the fluorescent light to be emitted. When the light surface emits light at a constant brightness and outputs a low level signal "L", the fluorescent surface does not emit light.

A lens (17) is provided close to the fluorescent surface of this cathode ray tube (16), and the microcapsule sheet (1) is placed at a position where the light emitted from the fluorescent surface forms an image with this lens (17). do.

Next, to explain the operation when exposing with this exposure device, first, as shown in Fig. 2, the terminal (14) is connected to a terminal (14) that repeats an increase every pixel period to (1/1000 of one horizontal scanning period). A sawtooth wave is obtained and a luminance signal is obtained at the terminal (11). Here, if a signal that changes from voltage value ■1 as shown in FIG. 3A to voltage value ■2 lower than ■1 during a predetermined period of time is obtained as a luminance signal, the output signal of the comparator (13) is the period t, as shown in FIG. 3B.
1, a high level signal "1" is output during the time t1 and t2 until the voltage level of the sawtooth wave exceeds vl and ■2, and a low level signal is output when the voltage level of the sawtooth wave exceeds vl and V2. A level signal It L w is output. Therefore, at this time, an electron beam is emitted from the electron gun of the cathode ray tube (16) for a period of t1 or t2 for each pixel period, and as shown in FIG. 4, a horizontal scanning line is formed on the microcapsule sheet (1). Electron beams b1 and b2 corresponding to voltage levels ■□ and ■2 are applied to each pixel along the line.

In this way, as the luminance signal level changes, the time irradiated onto the microcapsule sheet (11) changes for each pixel, and the irradiation area for each pixel changes corresponding to this irradiation time.Changes in this irradiation area. When viewed as a combination of two sides, changes in the brightness and darkness of the image correspond to changes in the irradiation area, and the density of the image exposed by irradiation changes depending on the level of the luminance signal.And, This image is printed by using the microcapsule sheet (1) on which one screen of light has been exposed in this manner and developing color on developer paper as shown in FIG.

In this manner, according to the exposure apparatus of this example, the irradiation area of the electron beam changes for each pixel in accordance with changes in the brightness of the input video signal, making it possible to reproduce the brightness and darkness of the image. In the case of this example, since the irradiation area of each pixel with the electron beam changes in proportion to the change in brightness, the intermediate tones of the image are well reproduced with continuous changes in gradation. Furthermore, since there is no need to change the luminance of the fluorescent surface of the cathode ray tube (16) caused by the electron beam, the configuration of the circuit for processing signals supplied to the cathode ray tube is simplified. In this example, the T characteristic of the exposed image can be adjusted by changing the characteristics of the sawtooth wave supplied to the input terminal (14).

Further, in the above embodiments, the case where the input video signal is an analog signal has been described, but the video signal can also be converted into a digital signal and processed. FIG. 5 is a diagram showing an exposure apparatus that handles this digital signal, and supplies a video signal of an exposed image obtained at a video signal input terminal (11) to an image processing circuit (21). This image processing circuit (21) supplies a pixel clock signal CK synchronized with the cycle of each pixel from a controller (22), divides each pixel into 256 gradations based on this clock signal, and indicates this gradation. An 8-bit digital signal is supplied to one comparison signal input terminal of a comparator (23) for each pixel. Furthermore, the pixel clock signal CK output by the controller (22) and the pixel clock signal CK
A pulse width control clock signal P having a shorter period than the pixel clock signal P is supplied to a counter (24), and this counter (24) counts the pulse width control clock signal P while resetting each time the pixel clock signal CK is supplied, and counts the pulse width control clock signal P to 8 bits. A digital signal is created, and the created digital signal is passed through a comparator (23
) to the other comparison signal input terminal.

This comparator (23) outputs a high level signal "H" while the signal supplied from the pixel processing circuit (21) for each pixel is larger than the signal supplied from the counter (24). When the value of the signal supplied from the counter (24) is larger, a low level signal "L" is output. The output signal of the comparator (23) is then supplied to the cathode ray tube (16) via the amplifier (15). The rest of the structure is the same as that of the exposure apparatus shown in FIG.

According to the exposure apparatus shown in the example shown in FIG. 5, an electron beam is emitted from each pixel for a time corresponding to the gradation of the image, as in the example shown in FIG. I did 2
56 gradations can be accurately reproduced.

Furthermore, although the above-described embodiments have been described with respect to a configuration in which monochrome exposure is performed, it is also possible to perform exposure of a color image. FIG. 6 is a diagram showing an example of this color image exposure apparatus, and (IIR) is shown in the figure.

(IIG) and (11B) indicate primary color signal input terminals from which red signal R1 green signal G and blue signal B are obtained, respectively;
This terminal (IIR), (IIG) and (11B)
The primary color signals obtained are supplied to the selector (31).

This selector (31) switches the primary color signal by a color switching controller (32), for example, every line, and the primary color signal output from the selector (31) is transferred to a pulse width modulation circuit (32).
33). This pulse width modulation circuit (33) is
A comparator (13) and an amplifier (12) as shown in FIG.
(15), and outputs a pulse signal having a width corresponding to the level of the primary color signal for each pixel. Then, the pulse signal outputted by the pulse width modulation circuit (33) is supplied to the cathode ray tube (16), and white light is emitted based on this pulse signal. Also, cathode ray tube (16) and lens (17)
A red filter (34R) and a green filter (34R) are connected between the
4G>, three color filters, a blue filter (34B), are arranged switchably, and these three filters (34R
), (34G).

(34B) is controlled by the color switching controller (32) in conjunction with the switching of the primary color signal by the selector (31). That is, the selector (31) selects the red signal R.
When the selector (31) is outputting the green signal G, the red filter (34R) is placed between the cathode ray tube (16) and the lens (17), and when the selector (31) is outputting the green signal G, the green filter (34G) are arranged in the same way, and when the selector (31) is outputting the blue signal B, the blue filter (34B
) are arranged in the same way.

With this configuration, the microcapsule sheet (1) is irradiated with red light, green light, and blue light alternately at predetermined intervals, and a color image of any color is created depending on the mixed state of the three colors. exposed to light. In the case of this example in FIG. 6 as well, the video signal is converted into a pulse signal corresponding to the gradation of the image for each pixel by the pulse width modulation circuit (33). Blue light is irradiated, and a color image corresponding to the eight floors of the image is exposed.

Although the above-mentioned embodiment is an exposure apparatus for microcapsule sheets, it goes without saying that the present invention can be applied to exposure apparatuses for various photosensitive materials that are exposed in the same manner. Furthermore, it goes without saying that the present invention is not limited to the above-described embodiments, and can take various other configurations without departing from the gist of the present invention.

〔Effect of the invention〕

According to the exposure apparatus of the present invention, since the area irradiated with light onto the photosensitive material changes depending on the level of the video signal, there is an advantage that an image of any gradation can be exposed onto the photosensitive material with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the exposure apparatus of the present invention, FIGS. 2, 3, and 4 are diagrams for explaining the example in FIG. 1, and FIGS. 5 and 6 are FIGS. 7, 8, and 9 are diagrams showing other embodiments of the exposure apparatus of the present invention, respectively, and are diagrams for explaining a printing method using microcapsules. (1) is a microcapsule sheet, (13) is a comparator,
(16) is a cathode ray tube.

Claims (1)

[Scope of Claims] Time modulation means that changes the pulse width according to the level of an input video signal, and a pulse signal outputted by the time modulation means is supplied, and light is emitted at a constant brightness for a time corresponding to the pulse signal. An exposure apparatus comprising: a cathode ray tube; and a photosensitive material is exposed to light irradiated by the cathode ray tube.