JP2897758B2 - Sub-exposure method for photosensitive recording medium and image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sub-exposure method for a photosensitive recording medium and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, a photosensitive recording medium used in this type of image forming apparatus is disclosed, for example, in US Pat.
No. 9,209 is known. As shown in FIG. 2, the photosensitive recording medium has such a characteristic that the photosensitive starts from the stage where a light amount exceeding a certain amount is irradiated. A photosensitive recording medium having such characteristics is
For example, when used as an image recording paper in a copier or the like, simply irradiating light from a light source onto a document surface and irradiating reflected light or transmitted light onto a photosensitive recording medium is insufficient in tone reproducibility.

Therefore, in general, an image forming apparatus that separately performs exposure (hereinafter, referred to as sub-exposure) in a stage before or after the above-described exposure (this is referred to as main exposure or main exposure) is generally considered. I have. By performing the sub-exposure, the photosensitive recording medium changes sensitively in accordance with the amount of energy irradiated during the main exposure, so that the gradation of an image can be improved.

That is, when the above-mentioned photosensitive recording medium is sub-exposed, light energy is applied to the microcapsules of the photosensitive recording medium until immediately before exposure, and when main exposure (main exposure) is performed according to image data, exposure is performed according to image data. Is performed, the gradation of the image is improved.

As a color image forming apparatus for performing exposure in this manner, first, an exposure amount shown in FIG. 2A is given to the entire photosensitive recording medium (sub-exposure), and then a liquid crystal shutter is operated in accordance with image data. A red component, a green component, and a blue component of a desired image are sequentially displayed, and are irradiated with red light, green light, and blue light, respectively (main exposure), and an image corresponding to the desired image is formed on a photosensitive recording medium. Devices are known.

[0006]

In such an apparatus as described above, in order to form a black portion on a photosensitive recording medium, it is necessary to not expose the microcapsules of the photosensitive recording medium.
Therefore, the exposure is performed by closing the cell corresponding to the black color of the liquid crystal shutter.

However, when sub-exposure is performed on the entire photosensitive recording medium and main exposure is performed, even if a corresponding pixel (cell) of the liquid crystal shutter is closed at the time of main exposure, light leakage may occur from the pixel. In addition, there is a disadvantage that the black portion is exposed due to light leaked from other pixels and the like, and the microcapsules are exposed by the leaked light, so that the black color of the original image is not reproduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gradation of an image is improved, and a black image is definitely formed in a portion where a black image is formed. It is an object to provide a sub-exposure method and an image forming apparatus for a photosensitive recording medium that can be formed.

[0009]

According to a first aspect of the present invention, there is provided a method for sub-exposure of a photosensitive recording medium, comprising the steps of: exposing a photosensitive recording medium upon receiving image data representing an image composed of a plurality of pixels; A sub-exposure method for a photosensitive recording medium for applying auxiliary exposure energy to the photosensitive recording medium when forming a latent image of an image, the method comprising: receiving a predetermined pixel in the image upon receiving the image data; A pixel portion that does not expose the recording medium is detected, and the auxiliary exposure energy is applied to the photosensitive recording medium corresponding to a portion excluding the detected pixel portion of the image.

According to the sub-exposure method for a photosensitive recording medium of the present invention, upon receiving image data, a pixel portion which is a predetermined pixel in the image and which does not expose the photosensitive recording medium is detected, and the detection of the image is performed. The auxiliary exposure energy is applied to the photosensitive recording medium corresponding to the portion excluding the pixel portion. For this reason, no auxiliary exposure energy is applied to the pixel portions where the photosensitive recording medium is not exposed, so that black color development can be reliably performed.

According to a second aspect of the present invention, there is provided an image forming apparatus, comprising: an optical shutter comprising a plurality of optical modulation elements each driven in accordance with input image data; and exposing a photosensitive recording medium via the optical shutter. In an image forming apparatus including a light source for forming a latent image corresponding to image data on the photosensitive recording medium, a detecting unit configured to detect, from the image data, image data of a portion where the photosensitive recording medium is not exposed, First control means for sub-exposing the photosensitive recording medium in a state where a light modulation element of the optical shutter corresponding to the portion not to be exposed is closed based on a detection result of the means, and the optical shutter based on the image data. And a second controller for exposing the photosensitive recording medium to light.

In the image forming apparatus according to the second aspect of the present invention, the detecting means detects, from the image data, image data of a portion where the photosensitive recording medium is not exposed, and the first control means detects the image data by the detecting means. Based on the result, sub-exposure is performed on the photosensitive recording medium with the light modulation element of the optical shutter corresponding to the unexposed portion being closed. The second control means drives the optical shutter based on the image data, and exposes the photosensitive recording medium.

Therefore, the light energy is not irradiated by the sub-exposure to the portion where the black latent image is formed on the photosensitive recording medium, and the microcapsules are exposed by the leakage light when the light modulation element of the optical shutter is in the closed state. Nothing to do.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the image data includes image data of each of red, blue, and green, and the detecting unit performs exposure in common with the image data of each color. The first control means is configured to detect a portion not to be exposed, and to perform sub-exposure on the photosensitive recording medium in a state in which a light modulation element of the optical shutter corresponding to the portion detected by the detection means is closed. .

In the image forming apparatus according to the third aspect of the present invention, the detecting means detects a portion of the image data of each color which forms one image and which is not exposed, and the first control means controls the detecting means. Based on the detection result, the photosensitive recording medium is sub-exposed in a state in which the light modulation element of the optical shutter corresponding to the unexposed portion is closed. The second control means drives the optical shutter based on the image data, and exposes the photosensitive recording medium.

Therefore, even if the image data indicates a color image, the portion where a black latent image is formed on the photosensitive recording medium is not irradiated with light energy by sub-exposure, and the light modulation element of the optical shutter is closed. Microcapsules are not exposed to light due to leakage light in the state.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, in the image forming apparatus 1 of the present embodiment, a halogen lamp 3 is used as an exposure light source, and near the halogen lamp 3, light emitted from the halogen lamp 3 is efficiently emitted. A reflector 5 for good use is arranged. A condenser lens 7 is arranged below the halogen lamp 3, and an infrared cut filter 9 for removing infrared rays from light transmitted through the condenser lens 7 is arranged below the condenser lens 7.

Below the infrared cut filter 9,
A filter unit 11 composed of color filters 11R, 11G, and 11B for decomposing light transmitted through the infrared cut filter 9 into any one of red (R), green (G), and blue (B); A rectangular liquid crystal display panel (hereinafter, referred to as LCD) 13 composed of cells (not shown) is arranged in that order. Under the LCD 13, a photosensitive pressure-sensitive paper (hereinafter referred to as microcapsule paper) 17 is provided.
Are arranged in close proximity. Here, each of the plurality of cells corresponds to the light modulation element of the present invention, the LCD 13 corresponds to the optical shutter of the present invention, and the microcapsule paper 17 corresponds to the photosensitive recording medium of the present invention.

The surface of the support of the microcapsule paper 17 is coated with microcapsules, and the microcapsules contain a dye precursor or the like that reacts with a developer described later.

The microcapsule paper 17 is housed in a state wound around a cartridge shaft 21 provided in a light-shielding cartridge 19.
A pair of feed rollers 23 for feeding the microcapsule paper 17 are provided on the right side of.

On the right side of the feed roller 23, the exposed microcapsule paper 17 and a developing paper 25 described later are overlapped, and the latent image formed on the microcapsule paper 17 is transferred to the developing paper 25. A pair of pressure rollers 27 is disposed below the pressure roller 27, and under the pressure rollers 27, the exposed microcapsule paper 17 separated from the developing paper 25.
There is provided a take-up shaft 29 for taking up.

A paper cassette 31 containing a plurality of developer sheets 25 is detachably mounted above the pressure roller 27, and the developer cassette 25 is stored above the developer cassette 31. A half-moon roller 33 that feeds out one sheet at a time is provided. On the left side of the half-moon roller 33, a paper feed roller 35 for feeding the sent developed color paper 25 to the pressure roller 27 is provided.
And a paper guide 37 for guiding the color-developed paper 25 are provided.

Further, on the right side of the pressure roller 27, a heat fixing device 39 for promoting the color development of the color developing paper 25 is provided. The heat fixing device 39 includes a heater 41 for heating and a transport belt 43 for transporting the color developing paper 25. A discharge port 45 for discharging the developed paper 25 on which an image is formed is formed in the housing 1a of the image forming apparatus 1 on the right side of the transport belt 43.

A color developing agent is applied to the surface of the support of the color developing paper 25 and develops a color by reacting with the dye precursor. The details are described in US Pat. No. 4,399,2.
09, and is omitted here.

Next, a control device 55 for controlling the image forming apparatus 1 will be described.

As shown in FIG. 1, the control device 55
A video interface 57 for inputting image data from the outside, and an A / A for digitally converting the input image data.
A D converter 59; a VRAM 61 for storing the converted image data for each of red, blue, and green data;
The CPU 65 reads out the red, blue, and green image data stored in the M61 as necessary, and transmits the read data to the LCD 13 through the LCD controller 63, and the lamp control circuit 67 and the filter control circuit 69 connected to the CPU 65. And an exposure time control circuit 73.

The lamp control circuit 67 controls the timing of turning on and off the halogen lamp 3 in response to a signal from the CPU 65, and the filter control circuit 69 controls the timing of the CPU 65.
And controls the driving of the motor 71 connected to the filter unit 11 in response to a signal from the filter unit 11. That is, LC
If the image data displayed in D13 is red image data, the red color filter 11R is inserted on the optical path. If the image data is green image data, the green color filter 11G is inserted on the optical path. Blue color filter 11B
Is controlled to drive the motor 71 so as to be inserted into the optical path.

Further, the LCD controller 63 has a V
Of the image data read from the RAM 61, non-exposure data corresponding to a portion where a black image is formed on the microcapsule paper 17 is detected, and the LCD 13 is driven based on the detected non-exposure data.

Next, the operation of the image forming apparatus 1 having the above configuration will be described.

First, when a print start signal is input from a terminal device (not shown), the CPU 65 activates the video interface 57 to capture image data. The image data is converted into red, green, and blue digital signals by the A / D converter 59. And the red image data is VRAM
The green image data is stored in 61 R blocks,
The blue image data stored in the G block of M61 is VR
It is stored in the B block of AM61.

On the other hand, the LCD controller 63 has a VRAM
The non-exposure data is detected from the image data stored in 61 and the cell of the LCD 13 corresponding to the non-exposure data is closed. Further, the filter control circuit 69 stores all of the color filters 11R, 11G, and 11B in the filter unit 11. Then, the halogen lamp 3 is turned on by the lamp control circuit 67, and the microcapsule paper 17 is exposed by the exposure amount indicated by B in FIG. 2 (sub-exposure). Here, the LCD controller 63 corresponds to the detection means of the present invention, and the CPU 65 and the like correspond to the first control means of the present invention.

Next, the CPU 65 sets the LCD controller 6
3 and the filter control circuit 69 to close all the cells of the LCD 13, drive the motor 71 to insert the red color filter 11R on the optical path, and transmit the red image data from the VRAM 61 to the LCD 13 for display. I do. At this time, the cell corresponding to the non-exposure data is closed.
Then, the light emitted from the halogen lamp 3 is efficiently condensed by the reflector 5 and the condenser lens 7 to become linear light, and the infrared cut filter 9 and the red color filter 11
R is transmitted to the entire surface of the LCD 13. Thereby, a latent image corresponding to the red image data is formed on the microcapsule paper 17.

When the red exposure is completed in this manner, L
All cells of the LCD 13 are temporarily closed by the CD controller 63. Then, after the red color filter 11R is stored in the filter unit 11 by the filter control circuit 69 and the green color filter 11G is inserted on the optical path, the green image data read from the VRAM 61 is Will be displayed. The cell corresponding to the non-exposure data is closed. Thereafter, a latent image corresponding to the green image data is formed on the microcapsule paper 17 as described above. When the green exposure is completed, the green color filter 11G is housed in the filter unit 11, and the blue color filter 11B is inserted into the optical path. Then, similarly, a latent image corresponding to the blue image data is formed on the microcapsule paper 17.
Here, the CPU 65 and the like correspond to the second control means of the present invention.

The microcapsule paper 17 that has been exposed in this manner is fed to the pressure roller 27 by the feed roller 23.
Sent to Then, the developed color paper 25 sent out from the paper feeding cassette 31 by the half-moon roller 33 and sent to the pressure roller 27 through the paper guide 37 by the paper feeding roller 35.
And the tip of the latent image formed on the microcapsule paper 17 are overlapped and inserted between the pair of pressure rollers 27. The latent image is transferred to the developed paper 25 by the pressure roller 27, and the microcapsule paper 17 is transferred to the developed paper 25.
And wound up on the winding shaft 29. On the other hand, the developer paper 25 is separated from the microcapsule paper 17 and sent to the heat fixing device 39. While the developed paper 25 is being conveyed by the conveyor belt 43, the color development of the developed paper 25 is promoted by the heater 41, and the developed paper 25 is discharged from the paper discharge port 45 as an image.

As described above, the microcapsule paper 17
Is exposed, the cells of the LCD 13 corresponding to the non-exposure data are closed when the sub-exposure is performed, so that no light energy is given to the portion of the microcapsule paper 17 corresponding to the non-exposure data. Therefore, when a latent image corresponding to each of the red, green, and blue image data is formed, a portion corresponding to the non-exposure data of the microcapsule paper 17 due to leakage light from cells other than the cell corresponding to the non-exposure data. Is exposed, the total amount of light energy applied to that portion does not reach the level at which the color density changes in the exposure characteristics of the microcapsule paper 17 shown in FIG.

That is, upon receiving the image data, a pixel portion which is a predetermined pixel in the image and which does not expose the photosensitive recording medium is detected, and the photosensitive portion corresponding to a portion of the image excluding the detected pixel portion is detected. An auxiliary exposure energy is applied to the recording medium. For this reason, the auxiliary exposure energy is not applied to the pixel portion where the photosensitive recording medium is not exposed.

As a result, when output as an image, the black portion of the original image is reliably output in black, and the other portions are not covered by the microcapsule paper 1.
7, after the sub-exposure, the microcapsule paper 17 is sensitively changed according to the amount of applied light energy, and is exposed based on the input image data. Can be output.

The present invention is not limited to the embodiment described above, and various changes can be made without departing from the gist of the present invention.

For example, the same sub-exposure as in the embodiment may be performed at the final stage of the exposure, or the sub-exposure may be performed by providing another light source for the sub-exposure.

[0041]

As is apparent from the above description, according to the sub-exposure method of the photosensitive recording medium according to the first aspect of the present invention, the photosensitive recording medium is exposed at predetermined pixels in the image upon receiving the image data. A pixel portion not to be detected is detected, and auxiliary exposure energy is applied to the photosensitive recording medium corresponding to a portion excluding the detected pixel portion of the image. For this reason, no auxiliary exposure energy is applied to the pixel portions where the photosensitive recording medium is not exposed, so that black color development can be reliably performed.

Further, in the image forming apparatus according to the second aspect, the light energy is not irradiated by the sub-exposure to the portion where the black latent image is formed on the photosensitive recording medium, and the light modulation element of the optical shutter is closed. Since the microcapsules are not exposed to light due to light leakage, the black portion of the original image is surely black and a high gradation image is formed in the portion where the black latent image is not formed. It has a very excellent effect that it can be produced.

Further, the image forming apparatus according to the third aspect has the effect of the second aspect, and can reliably form a black portion even if the image data is red, blue, and green color image data. It has a very good effect that it can be done.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus embodying the present invention.

FIG. 2 is a graph showing a relationship between an exposure amount of a photosensitive recording medium and a color density.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Halogen lamp 13 Liquid crystal display panel (LCD) 17 Photosensitive pressure sensitive paper (microcapsule paper) 63 LCD controller 65 CPU

Claims (3)

(57) [Claims] 1. A photosensitive recording method comprising: receiving image data representing an image composed of a plurality of pixels, exposing the photosensitive recording medium to form a latent image of the image, and applying auxiliary exposure energy to the photosensitive recording medium; A sub-exposure method for a medium, comprising: detecting a pixel portion that is a predetermined pixel in the image upon receiving the image data and that does not expose a photosensitive recording medium; and excluding the detected pixel portion of the image. A sub-exposure method for a photosensitive recording medium, wherein the auxiliary exposure energy is applied to the photosensitive recording medium in response to the above. 2. An optical shutter comprising a plurality of optical modulation elements each driven in accordance with input image data, and exposing a photosensitive recording medium through the optical shutter to form a latent image corresponding to the image data. An image forming apparatus including a light source formed on a photosensitive recording medium, a detecting unit configured to detect, from the image data, image data of a part that does not expose the photosensitive recording medium, and the exposing based on a detection result of the detecting unit. First control means for sub-exposing the photosensitive recording medium in a state where the light modulation element of the optical shutter corresponding to the portion not to be closed; and driving the optical shutter based on the image data, and An image forming apparatus comprising: a second control unit that performs exposure. 3. The image data comprises image data of each color of red, blue and green, wherein the detecting means detects a portion which is not commonly exposed to the image data of each color, and wherein the first control means comprises a detecting means. 3. The image forming apparatus according to claim 2, wherein the photosensitive recording medium is sub-exposed in a state in which a light modulation element of the optical shutter corresponding to a portion detected by the optical recording medium is closed.