JPH03188433A - Optical printer - Google Patents

Abstract

PURPOSE:To always maintain a developed image density at constant by adjusting an exposure light quantity by an image exposing means based on the change in the developing characteristics of a developing means. CONSTITUTION:A film 12 housed in a film magazine 11 passes through a carrying path 13 and reaches a laser image forming part 16. A laser beam radiated from a laser output part 17 is scanned by a polygon mirror provided in the laser output part 17, and after the radiation, it is reflected on a reflecting mirror 10 and scans the main scanning direction of a film surface based on image information. Concurrently, the subscanning direction intersecting orthogonally with the main scanning direction is scanned by subscanning rollers 18 and 19 and an latent image is formed on the film surface. The intensity of the laser beam reaching the film surface is entirely adjusted by an attenuator actuated by a control circuit. Thus, the image density is always maintained at a fixed value and a high-definition image can be recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to laser beam printers, CRT printers, L
The present invention relates to an optical printer such as an ED printer, and more particularly to an optical printer that can maintain a uniform density of a recorded image at a desired density by adjusting the amount of exposure light of an image exposure means.

[Prior Art] Optical printers such as laser beam printers and X-ray printers expose a photoreceptor to light based on image information to form a latent image, which is then developed by a developing device to make it visible. Devices of the form are known.

By the way, the following phenomenon occurs noticeably in printers that use a photosensitive recording medium such as a film or photographic paper as the photoreceptor and a liquid developing device as the developing device. That is, as the development process progresses, or as the amount of developing agent in the developer decreases, the development characteristics of the developer deteriorates, that is, the developer becomes exhausted, and the image exposure given to the recording medium decreases. Even if the amount of light remains the same, the density of the developed image gradually decreases. To deal with this problem, conventional devices display a warning to replace the developer when the amount of development processing exceeds a predetermined amount, or develop a test pattern in advance so that the density of the developed image decreases. There is a known system in which the operator adds replenishing developer after seeing what has happened.

[Problems to be Solved by the Invention] The conventional apparatus described above merely detects the amount of development processing or the developed image density of the test pattern, and replaces or replenishes the developer based on the results. As a result, replacement and replenishment of the developer solution becomes intermittent, and during this time, the density of the developed image becomes non-uniform, causing problems such as unstable image quality.

Furthermore, when using recording media such as color photographic paper, the three primary colors of yellow, magenta, and cyan are developed, but at this time, the color density changes of each color occur between the three primary colors due to exhaustion of the developer. There was a problem in that the color balance was disrupted and color images could not be faithfully reproduced.

[Means for Solving the Problems] The present invention solves the above problems, and uses light to perform image exposure on a photoreceptor based on image information, form a latent image, and develop the latent image into a visible image. In the printer, an exposure light amount adjustment means for adjusting the exposure light amount by the image exposure means, a development characteristic change detection means for detecting a change in the development characteristics of the developing means, and a development characteristic change detection means for adjusting the amount of exposure light by the image exposure means, and a development characteristic change detection means for detecting a change in the development characteristics of the developing means, and a development characteristic change detection means that adjusts the exposure light amount by the image exposure means, and ,
It is characterized by comprising a control means for adjusting the exposure light amount by the image exposure means by an exposure light amount adjustment means based on the change in the development characteristic of the development means detected by the development characteristic change detection means, When a photoreceptor is exposed to a plurality of lights of different wavelengths, a plurality of exposure light amount adjusting means are provided to individually adjust the exposure light amount, and the plurality of exposure light amount adjusting means are provided to adjust the exposure light amount individually based on changes in the development characteristics of the developing means. The present invention is characterized in that a control means is provided for controlling the adjustment of the exposure light amount according to the wavelength of the exposure light.

[Function] The amount of exposure light by the image exposure means is adjusted based on the change in the development characteristics of the developing means so that the developed image density developed and visualized becomes a predetermined density. is always kept constant.

[Embodiment 2] A first embodiment in which the present invention is applied to a laser printer that creates monochrome images will be described below.

FIG. 1 is a sectional view showing the main structure of a laser printer to which the present invention is applied, which is composed of an image forming unit section 1 and a developing device section 3. In this embodiment, the image forming unit section 1 and the developing device section 3 are configured to be separable, but they may also be configured as one piece.

The image forming unit section 1 will be explained. 11 is a film magazine in which a photosensitive film 12 is stored. 13
is a film conveyance path, which includes a conveyance roller 14 and a guide plate 1.
Consists of 5. Reference numeral 16 denotes a laser image forming section, in which a laser beam emitted from a laser output section 17 which is driven to emit light based on image information is reflected by a reflecting mirror 10, and an image is exposed onto a film. Rollers 18 and 19 are sub-scanning rollers that scan the film in the sub-scanning direction in synchronization with the emission of laser light. Note that the laser output section 17 is equipped with an attenuator, which will be described later, so that the intensity of the laser light that reaches the film, that is, the amount of image exposure light, is adjusted as a whole.

Next, the developing unit 3 will be explained. The developing unit 3 includes a developer tank 31, a fixer tank 32, a washing tank 33, a film drying section 34, and a processed film storage section 35. Each tank 31, 32, 33 is provided with a transport roller 36 and a guide plate 37 necessary for transporting the film.

Note that the developer tank 31 and the fixer tank 32 are provided with a heater for keeping the solution at a constant temperature, a pump for circulating the solution, and a mechanism necessary for replenishing and discharging the solution, and the washing tank 33 is provided with a water supply and drainage device. However, since this is a well-known method, a brief explanation of the drawings has been omitted. Furthermore, although the film drying section 34 is equipped with a fan 34a, a heater 34b, etc., other appropriate means may be employed.

An overview of the operation of the laser printer shown in FIG. 1 will be explained.

First, the film 12 stored in the film magazine 11 passes through the conveyance path 13 and reaches the laser image forming section 16 . The laser beam emitted from the laser output section 17 is scanned by a polygon mirror (described later) provided in the laser output section 17, and after being emitted, it is reflected by the reflection mirror 10 and forms an image on the film surface. Scanning is performed in the main scanning direction based on the information, and scanning in the sub-scanning direction perpendicular to the main scanning direction is executed by sub-scanning rollers 18 and 19 to form a latent image on the film surface. The overall intensity of the laser beam reaching the film surface is adjusted by an attenuator operated by a control circuit to be described later.

The film on which the latent image has been formed passes through the conveyance path 13,
Developer tank 31, fixer tank 32, washing tank 33
After being developed and dried in the film drying section 34,
The processed film is stored in the processed film storage section 35.

Figure 2 is a block diagram of the control circuit of a laser printer, showing only the control circuit portion that adjusts the intensity of the laser light that reaches the film surface, that is, the amount of image exposure light, based on the light transmittance detection signal of the developer. .

51 is a control CPU, and ROM 58.51 stores control programs, data, etc. RAM59. VRAM (non-volatile R
AM) 60. 57 is a polarizing plate constituting an attenuator, 52 is a D/A converter, 53 is a motor drive circuit, 53 is a stepping motor, and polarizing plate 57 is a D/A converter.
CPU 51 via A converter 52 and motor drive circuit 53
A stepping motor 54 driven by a signal supplied from the film rotates the plane of polarization by a required angle to adjust the intensity of the laser light that reaches the film surface, that is, the amount of image exposure light. 55 is a laser emitting element drive circuit, 56 is a laser emitting element, and the laser emitting element 56 is a C
Under the control of the PU 51, it is driven to emit light based on image information, and emits a laser beam with an intensity corresponding to the image information. 61
is a polygon mirror that performs scanning in the main scanning direction, and is rotationally driven by a drive mechanism (not shown). The laser light emitted from the laser light emitting element 56 is scanned by a polygon mirror 61,
A latent image is formed on the film surface 12. A light receiving element 62 is provided outside the main scanning area of the laser beam and detects the intensity of the laser beam reaching the film surface. The detection signal is converted into a normalized reference voltage by a signal conditioner, A/D converted, and input to the CPU 51.

Reference numeral 66 denotes a transmittance detection section made of a transparent glass tube provided in a part of the developing tank, through which a part of the developer is guided. 6
Reference numeral 5 denotes a light emitting element disposed close to the transmittance detection section 66 and driven by the light emitting element driving circuit 64. A light receiving element 67 detects the light emitted from the light emitting element 65 and transmitted through the transmittance detection section 66. A detection signal indicating the permeability of the developer is A/D converted by a signal conditioner and input to the CPU 51.

In this embodiment, when the developer is fatigued as a result of the development process and the development characteristics change, the image exposure light amount, that is, the exposure energy is adjusted to maintain the developed image density at a predetermined density. Therefore, a characteristic diagram showing the relationship between the light transmittance representing the fatigue level of the developer that changes in response to changes in the development characteristics, the developed image density, and the exposure energy is created in advance. This can be determined experimentally, and its −
An example is shown in FIG. The horizontal axis shows the light transmittance of the developer, and the vertical axis shows the image density on the film. That is, this figure shows that in order to obtain a predetermined standard image density Dn on the film, when the transmittance is αn, exposure energy En is required, and when the transmittance is αn-1, exposure energy En-1 is required. This shows that when the transmittance is αn-2, the exposure energy En-2 is required.

The light transmittance αn of the developer is determined as follows.

First, a new developer is injected into the developer tank 31, and the light emitted from the light emitting element 65 is detected by the light receiving element 67. The detected value In is obtained for the developer used in the processing in the same manner as before. The light transmittance αn is determined by the following formula.

αn=(In/10)X100 (%) --
(1) The appropriate exposure energy value for transmittance, which is necessary to obtain the reference image density shown in the characteristic diagram explained earlier (see Fig. 4), can be determined by the control circuit shown in Fig. 2 in the form of a conversion table. It is stored in the ROM 58 inside.

Next, the outline of the control operation will be explained with reference to the flowchart shown in FIG.

First, when a print execution command is input to the printer, the laser emitting element 56
is driven based on reference image information corresponding to the reference image density Dn to emit a laser beam (Step P1), which is detected by the light receiving element 62 and the radiant energy Eα is measured (Step P2>. The printer of this embodiment is a multi-gradation printer that reproduces 64 gradations, and the reference image information corresponding to the reference image density Dn is set to the image information corresponding to the 32-gradation part of the intermediate part.

However, as this reference image information, any image information may be set as appropriate without being specified as image information corresponding to the above part. Output (Step P3, Step P4
). Calculate the light transmittance αn according to equation (1) (Step P5), and determine whether the light transmittance αn is smaller than a predetermined limit value (Step P6), if the light transmittance αn is smaller than the predetermined limit value. indicates that the developer is exhausted and has reached its usage limit, so command replenishment of the developer (step P7).
Return to step P1. If it is determined in step P6 that the light transmittance αn is larger than the predetermined limit value, this indicates that the developer can still be used. Created ROM58
From the conversion table stored in , the reference image density Dn
Step P8) Find the energy En required to obtain
, find the difference ΔE between the required energy En and the previously detected energy Eα (step P9>, determine whether the difference ΔE is 0 or not (step PIO), and if it is not 0, perform PID control on the polarizing plate 57 of the attenuator. Rotate until it reaches 0 under (step P11). When the difference ΔE is 0, the process ends. After that, the printer enters a state in which the image recording operation is executed.

In the first embodiment, the decrease in density due to fatigue of the developer is corrected by the exposure light amount so that prints with a constant image density can be obtained, but it is necessary to change the image density depending on the purpose of use. In some cases, it is possible to obtain a print with a desired image density by adjusting the amount of exposure light while taking into account the degree of fatigue of the developer.

Next, a second embodiment will be described in which the present invention is applied to a color laser printer that creates color images.

FIG. 5 is a sectional view showing the main structure of a color laser printer to which the present invention is applied, which is composed of an image forming unit section E and a developing device section. In this embodiment as well, the image forming unit section E and the developing device section are constructed so as to be separable, but they may also be constructed integrally.

The image forming unit section E will be explained. A film magazine 111 stores a photosensitive color film 112. 113 is a film conveyance path, and conveyance roller 11
4. Consists of a guide plate 115. Reference numeral 116 denotes a laser image forming section, in which yellow, magenta, and cyan laser beams are emitted from a laser output section 117 that is NA#ed based on image information, and each laser beam of yellow, magenta, and cyan is combined into one beam and sent to a reflecting mirror 110.
The light is reflected and exposed as an image onto a color film. Rollers 118 and 119 are sub-scanning rollers,
The film is scanned in the sub-scanning direction in synchronization with the emission of laser light. Note that the laser output section 117 is equipped with an attenuator to be described later, and the laser output section 117 is equipped with an attenuator that will be described later.
The intensity of each cyan laser beam is corrected. The details will be described later.

Next, the developing unit will be explained. The developing unit includes a developer tank 131, a bleach-fix tank 132, and a stabilizer tank 1.
33, a film drying section 134, and a processed film storage section 135. Each tank 131, 132, 133 is provided with a transport roller 136 and a guide plate 137 necessary for transporting the film, as in the first embodiment.

In addition, these tanks 131, 132, and 133 are equipped with pumps to keep the liquid at a constant temperature, circulate the liquid, and replenish the liquid.
A mechanism necessary for ejection is provided, but since it is a well-known mechanism, a brief description of it in the drawings has been omitted.

Further, since the film drying section 134 has the same structure as that of the first embodiment, a description thereof will be omitted.

An overview of the operation of the color laser printer shown in FIG. 5 will be explained. First, the color film 112 stored in the film magazine 111 reaches the laser image forming section 116 via the conveyance path 113. The laser light emitted from the laser output section 117 is scanned by a polygon mirror, which will be described later, provided in the laser output section 117, and after being emitted, it is reflected by the reflection mirror 110 and forms an image on the film surface. In addition to scanning in the main scanning direction based on the information, the sub-scanning roller 11 performs scanning in the sub-scanning direction orthogonal to the main scanning direction.
8.119 to form an image latent image on the film surface. The overall intensity of the laser beam reaching the film surface is adjusted for each color of yellow, magenta, and cyan by an attenuator operated by a control circuit to be described later.

The film on which the latent image has been formed passes through a conveyance path 113, is processed in a developer tank 131, a bleach-fix tank 132, and a stabilizer tank 133, dried in a film drying section 134, and then transferred to a processed film storage section 135. will be stored in.

Figure 6 is a block diagram of the control circuit of a laser printer, and only shows the control circuit portion that adjusts the intensity of the laser light that reaches the film surface, that is, the amount of image exposure light, based on the light transmittance detection signal of the developer. .

151 is a control CPU, and a ROM 191.1 that stores control programs, data, etc. RAM192. It is the same as the first embodiment in that it includes a VRAM (nonvolatile RAM>193). 156Y, 156M, and 156C are laser light emitting elements that emit yellow, magenta, and cyan laser beams, respectively; This is a light emitting element drive circuit, which is driven to emit light based on image information under the control of the CPU 151. 157Y, 157M, and 157C are laser light emitting elements 156Y that emit yellow, magenta, and cyan laser beams, respectively. , 156M, 156C
This is a polarizing plate that constitutes an attenuator placed in front of the. 154Y, 154M, 154C are stepping motors that drive the polarizing plates of the corresponding attenuators, 152 is a D/A converter, 153 is a motor drive circuit, and polarizing plates 157Y, 157M, 1 of each attenuator are driven.
Stepping motors 154Y, 154M, and 154 57C are driven by correction signals supplied from the CPU 151 via the D/A converter 152 and the motor drive circuit 153.
The plane of polarization is rotated by the required angle by C. As a result, the intensity of the laser light that reaches the film surface, that is, the amount of image exposure light, can be adjusted independently for each color of yellow, magenta, and cyan.

158Y, 158M, and 158C are prisms that emit three beams from the laser emitting elements 156Y, 156M, and 156C.
It combines multiple laser beams into one beam.

Reference numeral 161 denotes a polygon mirror for scanning in the main scanning direction, which is rotationally driven by a drive mechanism (not shown) and scans the combined laser beams in the main scanning direction, forming a latent color image on the film surface 112. be done. Reference numeral 164 denotes a light receiving element provided outside the main scanning area of the laser beam, which detects the intensity of the laser beam reaching the film surface. The detection signal is converted into a normalized reference voltage by a signal conditioner, A/D converted, and input to the CPU 151.

Reference numeral 173 denotes a developer permeability detecting unit made of a transparent glass tube provided in a part of the developer tank 131, through which a part of the developer is guided. 172 A light emitting element disposed close to the transmittance detection section 173 and driven by the light emitting element driving circuit 171. 174 is a light receiving element, and the light emitting element 17
2 and transmitted through the transmittance detection section 173 is detected.

A detection signal indicating the permeability of the developer is normalized by a signal conditioner 175, A/D converted, and sent to the CPU 15.
1 is input.

Reference numeral 178 denotes a bleach-fix liquid permeability detection unit made of a transparent glass tube provided in a part of the bleach-fix tank 132, into which a part of the bleach-fix liquid is guided. Numeral 177 is a light emitting element disposed close to the bleach-fixing solution permeability detection section 178, and is driven by a light emitting element driving circuit 176. A light receiving element 179 detects the light emitted from the light emitting element 177 and transmitted through the bleach-fixing solution transmittance detection section 178. The detection signal indicating the permeability of the bleach-fix solution is signal conditioner 1.
The signal is normalized at 80, A/D converted, and input to the CPU 151.

FIG. 7 is a diagram showing the optical system of the laser output section 117.

On the optical path of the laser light emitting elements 156Y, 156M, and 156C that emit yellow, magenta, and cyan laser light, there is an attenuator 157 that corrects the intensity of the laser light.
Y, 157M, 157C and prisms 158Y, 158M, 158 for combining three laser beams into one
C is placed. On the optical path of the combined laser beam, there is a polygon mirror 161 for scanning in the main scanning direction,
A lens 162 and a mirror 110 are arranged so that a single combined laser beam is imaged on the film surface 112.

Further, a mirror 163 is arranged so that the laser beam is incident on the light receiving element 164 when it is outside the scanning area.

Next, the control operation of the second embodiment will be explained.

In this embodiment, as in the case of the first embodiment, the light transmittance αn representing the degree of fatigue of the developer changes in response to changes in development characteristics, and the reference color density D corresponding to predetermined image information.
The relationship with the exposure amount En (radiant energy of laser light) necessary to obtain n is experimentally determined for each color of yellow (Y), magenta (M), and cyan (C).

Note that the printer of the second embodiment is also a multi-gradation printer that reproduces 64 gradations (gradations for each color) like the printer of the first embodiment, and the reference image information corresponding to the reference color density Dn is , is set to image information corresponding to the 3211i tone portion of the intermediate portion. Of course, this reference image information is
It may be set to any image information as appropriate, without being specified to the image information corresponding to the above portion.

FIG. 10 is a characteristic diagram showing the relationship between the light transmittance of the developer and the exposure amount necessary to obtain the reference color density Dn,
If you create a conversion table for each color to determine the appropriate exposure amount for the light transmittance required to obtain the reference color density shown here, yellow (Y) can be calculated from the light transmittance αn of the developer.
), magenta (M), and cyan (C) (in this case, the wavelengths of yellow, magenta, and cyan are different).

The light transmittance αn of the developer is determined in the same manner as in the first embodiment. That is, first, a new developer is injected into the developer tank 131, the light emitted from the light emitting element 172 is detected by the light receiving element 174 toward the transmittance detector 173, and the zero-order development process is performed to obtain the detected value IO. The detected value In is obtained for the developer used in the same manner as before. The light transmittance αn is determined by the following formula.

αn= (In/IO)X100 (%) ・
(2) The conversion table for calculating the necessary exposure amount for each color of yellow, magenta, and cyan from the light transmittance αn of the developer explained earlier with reference to FIG. 10 is stored in the ROM 191 in the control circuit shown in FIG. is stored in.

Next, the outline of the control operation will be explained with reference to the flowchart shown in FIG.

First, when a print execution command is input to the printer, the laser emitting element 15
Step P101) to drive 6Y, 156M, and 156C to emit laser light based on predetermined reference image information;
This is detected by the light receiving element 164, and the radiant energies E, yα, Emα, and Ecα are measured for each color of yellow (Y), magenta (M), and cyan (C). Step P10
2).

Next, the light transmission intensity In of the developer is measured and output to the CPU 51 (step P103). Light transmittance αn (2)
Calculate according to the formula (step P104), light transmittance αn
It is determined whether or not is smaller than a predetermined limit value (step P105). If the light transmittance αn is smaller than the predetermined limit value, this indicates that the developer has become exhausted and has reached its usage limit, so replenishment of the developer is commanded (step P106), and after the completion of replenishment of the developer, the process returns to step P101. . Step P10
If the light transmittance αn is larger than the predetermined limit value in step P108, this indicates that the developer can still be used, and the process proceeds to step P108, where the exposure amount is corrected for each color of yellow, magenta, and cyan. Execute the process and end the process.

Since the exposure amount correction processing performed for each color of yellow, magenta, and cyan has almost the same processing procedure, the correction processing for yellow color will be explained here.

FIG. 9 is a flowchart of the yellow color correction routine. First, with reference to the conversion table stored in the ROM 191 (conversion table created based on the characteristic diagram shown in FIG. 10), the radiant energy Eyn of the laser beam necessary to obtain the reference color density Dn is detected. Next, the difference ΔEy between the radiant energy Eyα of the laser beam currently being emitted detected by the light receiving element 164 is calculated (Step P122).
), determine whether the difference ΔEy is 0 or not (step P123)
, if not O, adjust the polarizing plate 157Y of the attenuator by a predetermined amount (step P124), and return to step P121. If ΔEy=O in the determination in step P123, this means that the radiant energy of the laser beam has reached the energy Eyn necessary to obtain the reference color density Dn, and the process ends.

Radiant energy Em of each color laser beam of magenta and cyan
Corrections to obtain n and Ecn are performed in exactly the same manner.

Since the bleach-fix solution also becomes fatigued as the development process progresses, the fatigue of the developer also causes a decrease in the color density of the processed image. A bleach-fixing solution transmittance detection section 178 is provided that detects based on transmittance. Correction of the decrease in image color density due to exhaustion of the bleach-fix solution is performed simultaneously with correction of decrease in image color density due to exhaustion of the developer.

Specifically, the relationship between the light transmittance of the bleach-fix solution and the correction amount of laser beam radiation energy necessary to correct the decrease in image color density is calculated using correction coefficients pyn and pmn for each color of yellow, magenta, and cyan. , pcn and stored in the ROM 191. Next, the reference color density D obtained from the conversion table when correcting developer fatigue
The radiant energy of the yellow, magenta, and cyan laser beams Eyn, Emn, and Ecn required to obtain n are multiplied by the correction coefficients pyn, pmn, and pcn, respectively, to obtain the radiant energy of the laser beam E' yn (=Eyn Hpyn) E' mn (=Emn-pmn) E' cn (=Ecn-pcn).

In addition, if the permeability of the bleach-fix solution exceeds the limit value,
Replenish (replace) the solution in the same way as for the developer.

In the above embodiment, the degree of fatigue of the developer and bleach-fix solution is detected to correct the radiant energy of the laser beam, that is, the exposure amount. (residence time), development temperature (developer temperature), etc. may be used together for correction.

In the above embodiment, the attenuator is used to adjust the overall intensity of the laser light that reaches the film, but instead of adjusting the intensity using the attenuator, the driving voltage of the laser light emitting element is controlled and the laser light emitting element is The intensity of the laser beam reaching the film may be adjusted by changing its own emission intensity. In this way, the intensity of the laser light that reaches the film can be adjusted individually according to each image information, so by creating multiple conversion tables corresponding to each image information, Image exposure can be performed with an appropriate exposure amount for light transmittance corresponding to each image information, and image density and even color balance can be reliably kept constant over all gradation ranges. This is very effective when using a photoreceptor in which the contrast of a developed image changes significantly with changes in development characteristics.

In this case, methods for creating multiple conversion tables include storing all conversion tables in ROM;
Alternatively, a method may be adopted in which only conversion tables corresponding to typical light transmittances are stored in the ROM, and necessary conversion values are created at appropriate times through interpolation calculations.

In the embodiments described above, as a configuration for detecting changes in development characteristics, the light transmittance of the developer is measured and changes in development characteristics are detected from the light transmittance. In addition, it is also possible to measure the conductivity, PH1, or various ion concentrations of the developer, and detect changes in the development characteristics from the values. Further, although the present invention has been described in detail by taking a laser printer as an example, the present invention is applicable to not only laser printers as shown in the embodiments but also CRT printers, LED printers, LCD printers (liquid crystal printers), etc. In addition to printers that use silver halide photography, the present invention can also be applied to printers that use electrophotography, for example. Especially regarding color printers, in a color LCD printer, the exposure amount can be adjusted by correcting the voltage applied to each electron beam corresponding to the three colors; The amount of exposure can be adjusted by correcting the voltage applied to each color, and in a color LCD printer, the amount of exposure can be adjusted by correcting each LCD drive voltage corresponding to the three colors.

[Effects of the Invention] As explained above, according to the present invention, even if the developing characteristics of the developing means change, the image density is maintained at a predetermined density based on the change in the developing characteristics of the developing means. Since the amount of exposure light by the exposure means is adjusted, the density of the developed image is always kept constant regardless of the progress of the development process, and high quality image recording can be performed.

Furthermore, in recording a color image, since the amount of exposure light by the image exposure means is adjusted for each color, the color balance is also kept constant, and high quality images with good color balance can be recorded.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main structure of a laser printer according to a first embodiment of the present invention, FIG. 2 is a block diagram of a control circuit according to the first embodiment, and FIG. 3 is a control circuit according to the first embodiment. FIG. 4 is a characteristic diagram showing the relationship between the light transmittance of the monochrome developer, the image density on the film, and the exposure energy, and FIG. 5 is a flowchart explaining the control operation of the invention.
Cross-sectional view showing the main configuration of the laser printer of the embodiment, No. 6
The figure is a block diagram of the control circuit of the second embodiment, and FIG.
FIG. 8 is a perspective view showing the optical system of the laser output section of the embodiment;
FIG. 9 is a flowchart explaining the control operation of the control circuit of the second embodiment, and FIG. 10 is a characteristic diagram showing the relationship between the light transmittance of the color developer and the exposure energy necessary to obtain the reference color density. . 12: Photosensitive film, 112: Photosensitive color film, 51.151: CPU, 56°156Y,
156M, 156C: Laser light emitting element, 57.157Y
, 157M, 157C: attenuator polarizing plate, 61.
161: Polygon mirror 62, 164: Laser light receiving element, 65,172°177 = Light emitting element, 67.174
．． 179: Light-receiving element, 66. 173 2nd developer solution transmittance detection section, 178: Bleach-fix solution transmittance detection section.

Claims (3)

[Claims] (1) In an optical printer that performs image exposure on a photoreceptor based on image information to form a latent image, and develops the latent image to make it visible, an exposure light amount adjustment means that adjusts the amount of exposure light by the image exposure means; a developing characteristic change detecting means for detecting a change in the developing characteristic of the developing means; and a developing characteristic change detecting means for detecting a change in the developing characteristic of the developing means detected by the developing characteristic change detecting means so that the developed image density becomes a desired density. an optical printer comprising: control means for adjusting the amount of exposure light by the image exposure means by means of an exposure light amount adjustment means based on a change in the image exposure means. (2) In the optical printer according to claim 1, when the developing means is a liquid developing device, the developing characteristic change detecting means detects a change in the developing characteristics of the developing means based on the light transmittance of the developing solution. An optical printer featuring (3) In an optical printer that performs image exposure using multiple lights of different wavelengths to form a latent image on a photoreceptor and develops it to make a visible image, the amount of exposure light provided for each light of different wavelength is a plurality of exposure light amount adjusting means for adjusting; a developing characteristic change detecting means for detecting a change in the developing characteristic of the developing means; and control means for controlling the adjustment of the exposure light amount by the plurality of exposure light amount adjustment means according to the wavelength of the exposing light based on the detected change in the development characteristic of the developing means. printer.