JPH03139633A - Image forming device - Google Patents

Abstract

PURPOSE:To uniformize an amount of correction for a color picture by adjusting an amount of light with which a photosensitive recording medium is irradiated from a subexposure means, according to the type of a filter which the subexposure means selects. CONSTITUTION:The subexposure means M4 just irradiates the photosensitive recording medium M1 with color light independently of image exposure with light reflected from an original. Therefore, the latent image of an original is formed on the photosensitive recording medium M1 before or after or at the same time that the exposure carried out by the subexposure means M4. At the time of the subexposure, a means M5 for adjusting an amount of light adjusts an amount of light with which the photosensitive recording medium M1 is irradiated from the subexposure means M4, according to the type of the selected filter M3. Thus, an amount of the correction of tone for the final color picture is made uniform irrespective of a difference in tone.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention forms a latent image on a photosensitive recording medium using reflected light from an irradiated document, and then prints a color image on a recording sheet based on this latent image. The present invention relates to an image forming apparatus that forms images, a so-called color copying machine.

[Prior Art] There are three main types of color copying machines known: silver-salt type, electrophotographic type, and light-sensitive and pressure-sensitive type.

Among these, the photosensitive and pressure-sensitive method is a method in which a special film (photosensitive and pressure-sensitive paper) coated with countless microcapsules that react to red, green, and blue light is exposed to image light, transferred to developer paper, and fixed. Development and transfer are performed in one process (for example, as described in Chunichi Shimbun, December 2, 1988).

Among these, the color electrophotographic method and the photosensitive pressure-sensitive method use a photosensitive recording medium with lower sensitivity than the silver halide method, so when the gradation of each color cannot be satisfied simply with image light alone. There is. In such a case, it was necessary to improve the gradation by performing a separate exposure (sub-exposure) to achieve good color development. Furthermore, there is also a demand for freely expressing specific colors in a color image by intensifying or weakening them through this sub-exposure.For this reason, conventionally, before and after the area exposed to image light,
This sub-exposure device was sometimes equipped with a device that performs sub-exposure uniformly over the entire photosensitive recording medium (photosensitive drum, photosensitive pressure-sensitive paper, etc.).This sub-exposure device processes light from a light source through multiple filters with different hues according to the adjusted color. The photosensitive recording medium is exposed to light through a filter selected by the user.

[Problems to be Solved by the Invention] When color adjustment is performed by selecting a predetermined color filter from the plurality of filters having different hues, the adjustment is always stable and a color image with good color development is obtained when adjusting the same color. However, even though the same adjustment amount was set between filters of different hues, the amount of adjustment of the color that actually appears in the color image differs for each color.For this reason, the amount of adjustment made for a certain color may differ. Even if the same amount of adjustment is set in an attempt to achieve the same adjustment for other colors, the color image formed will not always be as expected.The present invention was made in view of the above problems. The purpose of this invention is to realize an image forming apparatus that can always form a color image with uniform adjustment regardless of the color, even if the same amount of adjustment is set.

[Means for Solving the Problems] In order to achieve the above object, the image forming apparatus of the present invention forms a latent image, After forming a latent image, in an image forming apparatus that forms a color image on a recording sheet based on this latent image, a color image is formed on the photosensitive recording medium M1 through one or more filters M3 selected from a plurality of filters M2 having different hues. a sub-exposure means M4 for adjusting the color of the color image by irradiating light with the sub-exposure means M4;
The sub-exposure means M depending on the type of filter M3 selected in
The present invention is characterized in that it includes a light amount adjusting means M5 that equalizes the amount of adjustment for a color image by adjusting the amount of light irradiated from 4 to the photosensitive recording medium M1.

[Function] The sub-exposure means M4 is configured to simply irradiate the photosensitive recording medium M1 with colored light, separately from image exposure based on reflected light from the original. A latent image of the original document is formed on the photosensitive recording medium M1 before, after, or simultaneously with the exposure by the sub-exposure means M4.

Therefore, for example, when a latent image that is to become a color image is irradiated with blue color light by the sub-exposure means M4, the entire image is adjusted to the blue side by a predetermined amount. Similarly, when the sub-exposure means M4 irradiates blue color light onto the photosensitive recording medium M1 before the latent image is formed, and then a latent image is formed on the photosensitive recording medium M1 based on the light reflected from the original. It's the same.

This sub-exposure is performed via filter M3.

However, the amount of transmitted light and the sensitivity to the photosensitive recording medium M differ depending on the color of the filter M3.
The effect given to 1 is not necessarily the same.

Therefore, during this sub-exposure, the light amount adjustment means M5 adjusts the amount of light irradiated from the sub-exposure means M4 onto the photosensitive recording medium M according to the type of filter M3 selected. As a result, the amount of color adjustment of the finally obtained color image can be made uniform regardless of the difference in hue.

[Embodiment] Hereinafter, an embodiment of the image forming apparatus of the present invention will be described with reference to the drawings. FIG. 2 is a schematic cross-sectional view of a photosensitive pressure-sensitive copying machine capable of full-color copying. Incidentally, photosensitive pressure paper (photosensitive recording medium) and color developer paper (recording sheet) that enable such copying are disclosed in Japanese Patent Application Laid-Open No. 58-88739, etc., and will not be described in detail here.

As shown in the figure, the top plate of the photosensitive and pressure-sensitive copying machine consists of a horizontally movable original platen glass 3 and an original platen cover 5. On the original platen glass 3, a desired original (
(not shown) can be placed face down. A light source consisting of a halogen lamp 7 extending in a direction perpendicular to the moving direction of the document table glass 3 and a semi-cylindrical reflecting mirror 9 arranged to surround it is fixed to the upper right side of the copying machine 1. Light is irradiated in a line toward the document table glass 3.

Therefore, the light emitted from the halogen lamp 7 can sequentially illuminate the entire surface of the document table glass 3 from the left end to the right end by moving the document table glass 3 in the left-right direction. The light emitted from the light source passes through the transparent document table glass 3 and is reflected by the document placed thereon. At this time, the document table cover 5 plays the role of covering the upper surface of the document table glass 3 so that the irradiated light does not leak from areas other than the document.

In addition, in order to utilize the light emitted from the halogen lamp 7 with high efficiency for irradiating the document, a beam flap 11 is installed to the left of the light source.
The light that is not directed directly toward the original is reflected and used to illuminate the original again. To the right of the halogen lamp 7, a fan] 3 and a louver 15 for introducing air from the outside are provided. As a result, cooling air is efficiently applied to the document table glass 3. Light emitted from the halogen lamp 7 and reflected from the document placed on the document table glass 3 passes through the filter]7 and enters the lens 19. The filter 17 is for changing the light transmission characteristics according to the sensitivity characteristics of the photosensitive pressure sensitive paper 21 and adjusting the color tone of the copied image. The lens 19 is mounted on a lens mounting plate 23, and allows minute angle adjustment with respect to the optical path.

The light focused by lens] 9 is reflected by two reflecting mirrors 25.
As a result, the direction is changed by 180°, and an image is formed on the photosensitive and pressure sensitive paper 21 which is closely positioned below the plate exposure table 27. two reflective mirrors 2
5 is fixed to the mirror mounting plate 29.Adjustment of the optical path length and focus adjustment are performed by fine adjustment of the mounting position of the mirror mounting plate 29.

On the other hand, a long photosensitive and pressure sensitive paper 2] is wound around a cartridge shaft 31 and housed in a removable cartridge 33 disposed below the document platen glass 3. It reaches a winding shaft 37 via a roller and a pressure developing device 35.

That is, the photosensitive and pressure sensitive paper 2 coming out from the lower part of the cartridge 33 is guided by the feed roller 39 and the roller 41 and passes below the exposure table 27, and then passes through the pressure developing device 3.
5. The photosensitive pressure sensitive paper 2 which has passed through the pressure developing device 35 is transferred to a peeling roller 43 and a meandering adjustment roller 45.
After being guided to the winding shaft 37, the winding shaft 37 winds up the winding shaft 37. It should be noted that the unexposed photosensitive pressure sensitive paper 21 immediately after leaving the cartridge 33 is held in an unexposed state by the light shielding cover 47.

The conveyance speed of the photosensitive and pressure sensitive paper 21 is controlled by the photosensitive and pressure sensitive paper feeding roller 49.
The latent images of predetermined lines of the original are sequentially formed on the photosensitive and pressure-sensitive paper 2 when it passes through the exposure stage 27 because the speed is controlled to be constant and the speed is matched to the moving speed of the original platen glass 3. Ru. Immediately after the latent image is formed, the photosensitive pressure sensitive paper 2 is subjected to sub-exposure with arbitrary color light by the sub-exposure unit 51.

Further, below the pressure developing device 35, a color developer paper cassette 55 is provided which accommodates a cut paper type color developer paper 53. The developer paper 53 is taken out one by one from the developer paper cassette 55 by the half-moon roller 57 and transferred to the developer paper roller 59.
After the leading edge is aligned by the resist gate 8-61, the photosensitive pressure sensitive paper 2
] and is transported to the paper inlet of the pressure developing device 35.

Therefore, the photosensitive pressure sensitive paper 21 and the color developing paper 53 are supplied to the pressure developing device 35 in a state in which they are in close contact with each other and are integrated. The pressure developing device 35 is composed of a small diameter roller 63 and a backup roller 65.

The microcapsule-coated surface of the photosensitive pressure-sensitive paper 21 on which the latent image is formed and the developer-coated surface of the color developer paper 53 are in contact with each other on the inside and are sandwiched between the small diameter roller 63 and the backup roller 65, and pressure is applied. Added. This pressure destroys the unexposed (i.e. uncured) microcapsules,
The internal coloring components are transferred to the color developer paper 53, and a color image is formed on the color developer paper 53.

Photosensitive pressure sensitive paper 21 and color developing paper 53 coming out of the pressure developing device 35
That is, the photosensitive and pressure sensitive paper 2 is transported upward by the photosensitive and pressure sensitive paper feed roller 49 and separated by the stripping roller 43, and the color developing paper 53 is separated in the perpendicular direction. The color developing paper 53 is accelerated to develop color by a heat fixing device 67 to form an image, and then transferred to a paper output tray 69.
It is transported with the image side up. The heat fixing device 67 includes a hollow heat roller 73 having a heater 71 therein, and a color developing paper feed roller 75.

Next, the operation of the photosensitive pressure-sensitive copying machine will be explained below.

Now, open the document platen cover 5, place the original on the document glass 3, return the document platen cover 5, and then press the start button on the panel (not shown). It moves to the right in the figure and stops at a position where the left end of the document table glass 3 faces the light source. Thereafter, with the halogen lamp 7 turned on, the document table glass 3 is moved to the left. The light emitted from the halogen lamp 7 is reflected by the original, passes through the filter 17 and the lens 9, and is reflected by the two reflecting mirrors 25, and then
An image is formed on the photosensitive pressure sensitive paper 21 located below the exposure table 27. At this time, the photosensitive and pressure sensitive paper 21 is being conveyed to the left on the exposure table 27 at the same speed as the moving speed of the document table glass 3, so the image on the document is formed as a latent image on the photosensitive and pressure sensitive paper 21. Ru.

Here, assuming that the original is a black and white printed matter, a latent image corresponding to the color black is formed.

Immediately thereafter, the sub-exposure unit 5 irradiates arbitrary colored light onto the entire photosensitive and pressure-sensitive paper 2 to adjust the color of the tongue latent image.

As the document platen glass 3 moves to the left, the color developer paper 53 is taken out from the color developer paper cassette 55 by the half-moon roller 57 and is supplied to the pressure developing device 35 in a state where it is overlapped with the exposed photosensitive pressure sensitive paper 2]. Ru. In this step, the latent image on the photosensitive pressure sensitive paper 21 is developed and transferred onto the developing paper 53.

Thereafter, the developing paper 53 is thermally fixed by a thermal fixing device 67 and then discharged outside the copying machine. On the other hand, pressure field image device 3
The photosensitive pressure sensitive paper 21 that has passed through the paper 5 is sequentially wound around the winding shaft 37. When the right end of the document platen glass 3 finishes moving to a position facing the light source, copying of the document is completed and the halogen lamp 7 is turned off. Developing paper 5 obtained in this way
The copied image shown in Figure 3 has colors adjusted by sub-exposure.

I Next, a configuration example and a control example of the sub-exposure unit 51 will be explained with reference to FIG. 3 and subsequent figures.

FIG. 3 shows an example of its configuration. Main sub-exposure unit 5
1 is composed of a light emitting section 81, a filter section 83, and a diffusion plate 85. The light emitting unit 8] is composed of a halogen lamp 87 for a light source with a reflector, and a lamp control circuit 89 that controls lighting of the halogen lamp 87 and the amount of light thereof.

The filter section 83 includes an actuator 93 that accommodates a plurality of filters 91 having different hues and can insert one or more arbitrary filters between the halogen lamp 87 and the diffusion plate 85, and an actuator drive circuit 95 therefor. has been done.

The diffusion plate 85 diffuses the colored light so that the colored light transmitted through the filter 91 is evenly irradiated onto the photosensitive and pressure sensitive paper 21 .

The lamp control circuit 89 and the actuator drive circuit 95 operate based on instructions from a copying control circuit 97 that controls the entire operation of the photosensitive and pressure sensitive copying machine. Also,
This command is determined based on the input operation from the panel 99 for inputting the working conditions of the entire photosensitive and pressure sensitive copying machine. The copy control circuit 97 is an electronic circuit mainly composed of a known microcomputer, and since such a hardware configuration is well known, a detailed explanation will be omitted.

Among the processes executed by the copy control circuit 97, flowcharts of processes related to sub-exposure are shown in FIGS. 4 and 5.

The filter selection and lamp light intensity setting routine shown in FIG. This process is performed as part of the process of reading input values from the panel 99.

First, input values regarding color adjustment are read from the panel 99 (S110). From this input value, a filter number representing the type (hue) of the filter 9 is obtained, and this value is stored in a RAM or the like (S120). Depending on the hue to be adjusted, it may be necessary to use two or more filters 91, so there may be multiple filter numbers.

Next, based on the type of filter 9, the required amount of pump light is searched from the table written in the ROM.
It is stored in RAM (S130).

This table describes the amount of lamp light at which the adjustment amount for each color is the same depending on the type of filter 9]. The relationship between the filter 91 and the amount of light is measured and stored in advance through visual observation by a device or a person.

When a plurality of filters 91 are stacked, the amount of lamp light is determined based on a combination table that has been measured in advance by combining a plurality of filters 91. Filter 9
Regarding combination 1, in addition to this, the amount of lamp light for the combination may be calculated by subtractive color mixture calculation based on the amount of lamp light obtained from the table for each filter.

Next, switch filter 9 according to the settings (S140)
. That is, a necessary filter 9] is inserted between the halogen lamp 87 and the diffusion plate 85. After this, the process moves to other setting processing.

In this way, the setting process is completed, and the next step is to proceed to the copy process. The copy process is started by pressing the copy start button on panel 99. FIG. 5 shows a sub-exposure control routine executed during the copying process.

First, it is determined whether or not it is the timing to turn on the lamp 87 based on the amount of conveyance of the photosensitive and pressure sensitive paper 2 detected by an encoder (not shown) (S210). If the image-exposed portion of the photosensitive pressure sensitive paper 2 has not reached the sub-exposure position, a negative determination is made and the process moves to lamp extinguishing control (S215). At this time, since the first lamp 87 is off, the process moves directly to other processing. The above negative judgment is repeated until the lighting timing is reached, and the lamp 87 is not lit.

When the image-exposed portion reaches the sub-exposure position, it is determined that the lighting timing has arrived and the lamp 87 is then turned on. At this time, the lamp control circuit 89 is controlled so that the lamp light intensity is the same as that already searched from the table and stored in the filter selection and lamp light intensity setting routine (S220).

5- The lamp control circuit 89 includes, for example, a chopper circuit for output voltage to the lamp 87, and changes its duty according to the light amount signal of the copy control circuit 97 to adjust the lamp light amount. In this way, as long as the lighting timing is met, that is, as long as the image-exposed portion of the photosensitive pressure sensitive paper 21 is passing through the sub-exposure position, the lamp lighting and light amount control processing is repeated.

If it is determined by the encoder measurement that the image-exposed part has passed through the sub-exposure position, a negative judgment is made as it is not the timing to turn on the lamp.
S215) is executed and the lamp 87 is turned off.

Each time the image-exposed portion of the photosensitive pressure sensitive paper 2 reaches the sub-exposure position, the above-described process is repeated to adjust the color of the latent image on the photosensitive pressure sensitive paper 21.

If you want to make the same adjustments for other colors, use panel 9.
By inputting from 9, only the color designation (filter designation) can be changed, and the adjustment amount can be changed by one step.

With this setting change, an appropriate filter 91 corresponding to the adjusted hue is selected again in the filter selection and lamp light intensity setting routine (Fig. 4) (S120), and the lamp light intensity corresponding to that filter 9 is searched.・Remembered (S
130). Then, based on the stored lamp light amount, color adjustment is performed in the sub-exposure control routine (FIG. 5), so that the same adjustment as the hue to be adjusted last time is achieved.

In the embodiment described above, the sub-exposure unit 51 was arranged to irradiate the light-sensitive and pressure-sensitive paper 21 with color light for adjustment after being exposed to image light. The arrangement may be such that colored light is irradiated and then exposure with image light is performed. Further, color light for adjustment may be irradiated during exposure with image light.

In the above embodiment, the amount of light irradiated onto the photosensitive and pressure sensitive paper 21 is controlled by the amount of light of the lamp 87 itself, but an electric aperture is provided between the lamp 87 and the filter 91, or between the filter 9] and the diffuser plate 85. The amount of light irradiated onto the photosensitive and pressure sensitive paper 2 may be adjusted by providing a device and controlling the copying control circuit 97. In this case, the aperture amount for each type of filter 91 is written in the table in the ROM.

The above embodiment may be further configured so that a plurality of color adjustment amounts can be set in stages. For example, if you set the adjustment amount to "large",
There are three levels: ``medium'' and ``small.'' To achieve this, the lamp lighting light amount control process (S220
), the amount of lamp light obtained from the table may be corrected using correction coefficients set at values corresponding to the stages. For example, if the adjustment amount is set to "Large",
What is necessary is to calculate the product of the correction coefficient for "dog" and the lamp light quantity, and issue a command to the lamp control circuit 89 as a new lamp light quantity.

Effects of the Invention As detailed above, in the present invention, when the sub-exposure means irradiates the photosensitive recording medium with colored light, the light amount adjustment means adjusts the amount of light irradiated from the sub-exposure means to the photosensitive recording medium by adjusting the hue of the filter. Even if they are different, the color adjustment amount is adjusted to be uniform. Therefore, the color image finally obtained is obtained in the color adjustment state as set, regardless of the difference in hue to be adjusted.

[Brief Description of the Drawings] Fig. 1 is a diagram illustrating the basic configuration of the present invention, Fig. 2 is a schematic sectional view of a photosensitive pressure-sensitive copying machine according to an embodiment thereof, and Fig. 3 is an example of the configuration of a sub-exposure unit. FIG. 4 is a flowchart of filter selection and lamp light amount setting among the controls executed by the copying control circuit, and FIG. 5 is a flowchart of the sub-exposure control routine. 1... Light and pressure sensitive copying machine 21... Light and pressure sensitive paper 8
7... Halogen lamp for light source with reflector 89...
Lamp control circuit 91... Filter 93... Actuator 97... Copy control circuit 95... Actuator drive circuit

Claims (1)

[Scope of Claims] 1. In an image forming apparatus that forms a latent image on a photosensitive recording medium using reflected light from an irradiated document, and then forms a color image on a recording sheet based on this latent image, the photosensitive recording medium a sub-exposure means for adjusting the color of the color image by irradiating light through one or more filters selected from a plurality of filters having different hues; and a type of filter selected by the sub-exposure means. 1. An image forming apparatus comprising: a light amount adjusting means that equalizes the amount of adjustment for a color image by adjusting the amount of light irradiated from the sub-exposure means to the photosensitive recording medium according to the amount of light irradiated onto the photosensitive recording medium from the sub-exposure means.