JPH0276763A - Image formation device - Google Patents

Abstract

PURPOSE:To make possible the formation of only an image with less conspicuous appearance of color mixture by utilizing the correlationship between the output current of a light-receiving element and the temperature of a laser diode to compare a current value set at a value corresponding to a temperature in the wavelength where a color mixture begins to become conspicuous and an electric current from the light-receiving element. CONSTITUTION:A signal from an image processing section 20 controls an electric current from a constant current circuit 314 to cause a laser diode LD1 to emit light. In addition, a light-receiving element PD1 detects a light output from the laser diode LD1, and a logic operation circuit 324 corrects an output, from the constant current circuit 314, which varies according to temperature. A logic operation circuit 326, into which an LD current is entered has the setting value of a PD current generated by the light receiving element at a temperature in which a color mixture becomes conspicuous. Said circuit 326 compares a signal from an A/D converter in which data is entered with a PD current value when said signal is output, and outputs a signal S2, if the setting value is exceeded, to prevent the formation of an image with a conspicuous appearance of mixed colors.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus that forms an image using semiconductor light emitting elements in response to image information.

[Conventional technology]

2. Description of the Related Art Conventionally, as an apparatus for copying a color original, an apparatus for copying a desired color original using a silver halide color photosensitive material is known. For example, there is a color copying device commercially available under the trade name Cibachrome Color Copy CC-001J (manufactured by Ciba Geigy), which uses the so-called silver dye bleaching method that combines photosensitive silver halide and azo dye. This is a copying device that reproduces color images using silver dye bleach (SDR) color photosensitive materials.

In addition, there are other copying apparatuses that use a photothermographic material as an image recording material. For more information on this heat-developable photosensitive material and its process, see Basic Non-Silver Salt Photography for Photographic Engineering! (Published by Corona Publishing, 1982), page 242~
255 pages, 40 pages of video information published in April 1978, Nebrezoc Handbook op Photography (Neb
letL's Handbook of Photog
Raphy and Reprography) 7th Ed, Van Nostrand Reinhold Company (Van No5trand Re1
nhold Company), pages 32-33.

Furthermore, many methods have been proposed for obtaining color images by heat development.

For example, releasing a mobile dye in an image-like manner by heating,
A method of transferring this mobile dye to a dye-fixing material containing a mordant using a solvent such as a groove, a method of transferring it to a dye-fixing material using a high-boiling point organic solvent, a method of transferring this mobile dye to a dye-fixing material using a hydrophilic thermal solvent built into the dye-fixing material. A method in which the mobile dye is heat-diffusible or sublimable and is transferred to a dye-receiving material such as a support has been proposed. (U.S. Patent Nos. 4,463,079 and 4,474,867)
No. 4,478,927, No. 4,507,38
No. 0, JP-A-58-149046, JP-A No. 58-149
No. 047, No. 59-152440, No. 59-15
No. 4445, No. 59-165054, No. 59-180
No. 548, No. 59-168439, No. 59-174
No. 832, No. 59-174833, No. 59-1748
34, No. 59-174835, etc.) As an apparatus for carrying out this type of image forming method, for example,
As disclosed in Japanese Patent No. 9-75247, after exposing a color image to a heat-developable photosensitive material in an exposure section,
Applying an image forming solvent such as water to a heat-developable photosensitive material,
An image recording apparatus has been proposed in which the image is sent to a heat development section, the image receiving material is brought into close contact with the photothermographic material in the heat development section, and the image is transferred to the transfer section, where the image is thermally transferred to the image receiving material.

In the above-mentioned exposure section, after scanning the original and converting it into an electrical signal, a point light source such as a laser diode is used to irradiate the light emitted from the point light source onto the surface of the photosensitive material at the same time to a portion corresponding to the smallest unit pixel. An image recording apparatus has been developed that forms an image (or latent image) on the photosensitive material by sequentially scanning the photosensitive material.

[Problem to be solved by the invention]

Laser diodes, which serve as point light sources, have the characteristic that their emission wavelength shifts toward longer wavelengths due to temperature increases caused by continuous irradiation.

Here, the sensitivity of the photosensitive material to the three primary colors (magenta, yellow, cyan) is completely separated, for example,
The sensitivity distribution shown in the figure corresponds to the emission wavelength of the laser diode.

For this reason, the emission wavelength of the laser diode is the wavelength at which color mixture is least noticeable, but as the amount of deviation in the emission wavelength increases as described above, color mixture becomes noticeable.
In the case shown in the figure, the rate of color mixing between yellow and cyan is high.

This is particularly a serious problem for photosensitive materials in which sensitivity distributions overlap relatively frequently.

An object of the present invention is to address the above-mentioned problems and provide an image forming apparatus that can detect changes in the emission wavelength of a laser diode and form an image (or latent image) in which color mixture is not noticeable.

[Means to solve the problem]

The apparatus of the present invention detects a change in the emission wavelength of the semiconductor light emitting element or a quantity having a change corresponding to a change in the emission wavelength in an image forming apparatus that forms an image using a semiconductor light emitting element in accordance with image information. The above-mentioned problem is solved by a configuration having a means for detecting a value detected by the detecting means and a comparing means for detecting that the value detected by the detecting means is greater than or equal to a predetermined value.

That is, the detection means and the comparison means detect the wavelength change of the laser diode, which is a semiconductor light emitting element, and can detect when the degree of color mixture is large, and it is possible to form an image only when the color mixture is inconspicuous.

[Embodiment]

The apparatus of the present invention will be explained below with reference to the drawings.

FIG. 1 is a schematic diagram of an image recording apparatus to which an image forming apparatus of the present invention is applied.

This image recording apparatus requires a heat development process and uses a type of photosensitive material in which an image is transferred and formed on an image receiving material having an image receiving layer in the presence of an image forming solvent such as water.

Inside the housing 12 constituting the image recording device, there is a photosensitive material supply section 13 that stores the photosensitive material A, an image exposure section 15 that reads image information carried on the document S, and a latent image formed on the photosensitive material A. an exposure position section 16, a water application section 17 that applies water to the photosensitive material A, an image receiving paper supply section 41 that stores the image receiving paper C, an overlapping section 19 that superimposes the image receiving paper C on the photosensitive material A, and a photosensitive material A. A heat development transfer section 21 that heats the material A and the image receiving paper C, and a peeling section 23 that separates the image receiving paper C from the photosensitive material A are provided.

A transparent document support glass plate 14 on which the document S is placed is arranged on the upper surface of the housing 12, and the image exposure section 15 is arranged below this document support glass plate 14.

This image exposure section 15 includes an image reading section 200 and an image processing section 2.
50, and an optical system 300. An exposure opening 34 corresponding to the exposure position 16 of the photosensitive material A is defined in a portion through which the optical axis 32 of the image exposure section 15 passes.

Further, a standard white plate 302 is provided near the original support glass plate 14 so that it can be exposed to light ita.

On the other hand, the photosensitive material supply section 13 is provided on the left side of the housing 12 and is kept light-tight. This photosensitive material supply section 13 is loaded with a removable photosensitive material magazine 54 in which photosensitive material A is wound.

The photosensitive material supply section 13 has roller pairs 56a to 56d that transport the photosensitive material A from the magazine 54 to the exposure position 16. In this case, a cutter 58 for cutting the photosensitive material A into predetermined lengths is provided between the pair of rollers 56a and 56b. Further, the exposure table 60 disposed between the pair of rollers 56c and 56d faces the exposure opening 34 defined on the bottom surface of the partition wall 22 surrounding the image reading section 15.

In front of the exposure position 16 (hereinafter, "front" refers to the downstream side in the direction of travel of the photosensitive material, etc.) is provided with a conveyance path consisting of a pair of rollers 56e and a guide plate.

At the exposure position 16, the photosensitive material A is imagewise exposed to form a latent image, and the photosensitive material A on which the latent image is formed is conveyed to the water application section 17 via the conveyance path.

The water application section 17 is for facilitating the transfer of the latent image formed on the photosensitive material A, and includes a roller pair 56f1, a squeeze roller pair 176, a guide plate 172, a water tank 174, and the like. Then, the water tank 174 is filled with water, and the photosensitive material A is transported while being immersed in the water.

The photosensitive material A coated with water is squeezed by a pair of squeeze rollers 176.
It is conveyed to the overlapping section 19 by.

On the other hand, on the right side of the housing 12, a receiving paper supply section 41 for supplying the receiving paper C is provided. The image receiving paper supply section 4
1 is a receiving paper magazine 43 that stores rolled receiving paper C;
is loaded. The image receiving paper C in the magazine 43 is transferred to the roller pair 5.
6h, and cut into a predetermined length by a cutter 44 disposed in front of the pair of rollers 56h.

The cut image-receiving paper C is conveyed to the overlapping section 19 by a pair of rollers 56i.

In front of the overlapping part 19, the overlapping photosensitive materials A
A heating development transfer section 21 is provided which heats the image receiving paper C, develops the latent image on the photosensitive material A, and transfers it onto the image receiving paper C.

The heat development transfer section 21 is surrounded by a heat insulating partition wall 62, and is wound around a hollow cylindrical heating drum 74 containing a halogen lamp 72 at an angle of about 270'' around the outer peripheral surface of the heating drum 74. It includes an endless belt 84 supported by four belt support rollers 76, 7?, 78, 80, and heats the photosensitive material A and image receiving paper C in a superposed state.By this heating, the latent on the photosensitive material A is heated. The image is developed and transferred onto the image receiving paper C to develop color.

A peeling section 23 is provided in the corner wall 62, and the peeling section 23 includes a first peeling claw 232 for peeling the photosensitive material A from the image receiving paper C, and a first peeling claw 232 for peeling the image receiving paper C from the heating drum 74. It consists of a second peeling claw 234 and a roller 56j that discharges the image receiving paper C to the outside of the partition wall 62.

In front of one side of the heat development transfer section 21, there is a waste tray 118 for discarding the heated photosensitive material A peeled from the image receiving paper C by the peeling claw 232, and a pair of rollers 56k for throwing the photosensitive material A into the waste tray 118. is provided. The waste tray 118 is provided below the heat development transfer section 21 .

In addition, in front of the other side of the heat development transfer section 21, there is a take-out tray 120 for storing the heated image receiving paper C, and a pair of rollers 561.56 m for conveying to the take-out tray 120.
56n is provided, and the image-receiving paper C on which the image has been transferred is led out to the take-out tray 120.

Further, a color density detection unit 124 for detecting the color density of the image on the image receiving paper C is arranged between the pair of rollers 56m and 56n. The color density detection unit yh124 includes an illumination device 126 that illuminates the image surface of the test paper C, and a color photo sensor 12 that receives reflected light from the image receiving paper C due to this illumination.
It consists of 8.

The apparatus further includes a color density control unit 1 connected to the imaging lens/filter unit assembly 30 and the photosensor 128 and disposed at a suitable location within the housing 12.
50, the color density control unit 150, the photosensitive material supply section 13, the image exposure section 15, and the drive system of the image exposure section 15 (
(not shown), image receiving paper supply section 41, cutter 44.58,
A system control device (not shown) is provided which is connected to the shutter control device 36, the water application section 17, the heat development transfer section 21, and the peeling section 23 and controls the entire apparatus.

Here, in the image exposure section 15, as shown in FIG. Mirrors 212 and 214 move in the same direction and reflect the light of the illumination lamp 208 in that direction.
The original image is converted into an electric signal by an imaging lens 218 on the optical axis from the mirror 214 and a CCD unit 220 that performs photoelectric conversion and is output to an image processing section 250.

The image processing unit 250 receives signals from the color density control unit 150, applies various corrections to the digitized image information, determines the exposure amount for each color of cyan, magenta, and yellow, and sends the signal to the optical system 300. Output.

In the optical system 300, laser diode drivers 255 and 256 for cyan, magenta, and yellow colors are provided.
．． 257, the laser diodes of each hue emit light according to the signal from the image processing section 250, and the collimator lenses 258. '259, 260, a mirror 261, and half mirrors 262, 263 form the same optical axis, horizontal scanning is performed by a polygon mirror 270, and the photosensitive material A is exposed through a cylindrical lens 280 and a dichroic mirror 290.

FIG. 3 is a block diagram of a laser diode driver.

Since each of the drivers 255, 256, and 257 has a similar configuration, the driver 255 will be used for explanation.

The signal from the image processing section 250 passes through the modulation circuit 312 and controls the current from the constant current circuit 314 to cause the laser diode LDI to emit light. Furthermore, the light output of the laser diode LDI is detected by the light receiving element PDI. This is because the output of the laser diode LDI varies depending on the temperature even when a constant applied current is applied, so it compensates for fluctuations in optical output. Constant current circuit 31 by 324
This is to correct the output of '4.

On the other hand, when the temperature rises, not only the optical output decreases as shown in FIG. 4, but also the emission wavelength shifts to the longer wavelength side as described above, and color mixture may become noticeable.

Therefore, a signal corresponding to the PD lightning current from the light receiving element PDI, which has been converted into a digital signal by the A/D converter 322, is input to the logic operation circuit 326.

Furthermore, the logic operation circuit 326 inputs the LD current to the laser diode LDI, and further calculates the PD ii 'm value generated in the light receiving element PDI at a temperature at which color mixing would be noticeable with respect to this current value. The A/D converter 322 is set in advance and the input signal from the A/D converter 322 is compared with the PD current value set at the point where color mixture is extremely noticeable corresponding to the LD current at that time.
When the signal from the D converter exceeds this PD lightning current setting value, a signal S2 is output.

With this signal S8, for example, the danger of color mixture is displayed on a display device (not shown), the exposure operation is temporarily stopped, and the exposure operation is restarted when the value becomes lower than the set value.
By operating a forced cooling means such as a cooling fan and continuing exposure, formation of an image with significant color mixture can be prevented.

In this embodiment, the color mixture state is compared by converting the shifted emission wavelength of the laser diode into the output current of the light receiving element corresponding to this temperature based on the corresponding temperature of the laser diode. However, other methods include methods that directly measure wavelength, and methods that measure and compare temperatures using thermocouples or the like.

〔Effect of the invention〕

Using the fact that the output current of the light receiving element corresponds to the temperature of the laser diode as described above, the current from the light receiving element is compared with the current value set at a value corresponding to the temperature at the wavelength where color mixture becomes noticeable. By doing so, it is possible to detect the temperature corresponding to the wavelength at which color mixture starts to become noticeable, and it becomes possible to form only an image (or latent image) in which color mixture is not noticeable.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an image recording device to which the device of the present invention is applied, Fig. 2 is a schematic diagram of the exposure section, Fig. 3 is a block diagram of the laser diode driver, and Fig. 4 is the previous Kerr LD current. and a graph showing the PD current characteristics. FIG. 5 is a graph showing the sensitivity distribution of the photosensitive material and the emission wavelength of the laser diode. Reference symbols in the figure: 12...Housing 13...Photosensitive material supply section 14...Original support glass plate 15...Image exposure section 17...Water coating section 18...Light source 19...
・Overlapping portion 21...heat development transfer portion 23・
... Peeling section 30 ... Imaging lens/filter unit assembly 33
．． 35...'J1m claw 41...Receiving paper supply unit 43...Receiving paper magazine 44.58...Kander 54...Sensitive material magazine 56a-56n...
・Roller pair 60...Exposure table 72...Halogen lamp 74...Heating drum 76.77.78.80...Belt support roller 84.
... Endless belt 118 ... Waste tray 120 ... Take-out tray 124 ... Color density detection unit 126 ... Lighting device 128 ... Color photo sensor 150 ... Color density control unit 172 ... Guide Board 174...Aquarium 176
... Squeeze roller 200 ... Image reading section 208
...Illumination lamp 210.212.214...Mirror 218...Imaging lens 220...CCD sensor 230...Aperture 250...Image processing unit 300...Optical system 312...Modulation Circuit 316.320...Current/voltage converter 318...Digital/analog converter 322...Analog/digital converter 324.326...Logic operation circuit LDI...Laser diode PDI...Light reception Element A...Photosensitive material C...
Image receiving paper No. 3 fjS4Fig.
f124th 1, Indication of the case Patent Application No. 228337 of 1988 2, Title of the invention Image Formation 5A Fall 3, Person making the amendment Relationship to the case: Name of the patent applicant (520) Fuji Photo Film Co., Ltd. 4, Agent Address: 3-2-5 Yuugaseki, Chiyoda-ku, Tokyo 100
No. 29th floor, Kasumigaseki Building, Post Office, P.O. Box 49, Kasumigaseki Building
No. Eikou Patent Office 5, date of amendment order: (voluntary)

Claims (1)

[Claims] In an image forming apparatus that forms an image using a semiconductor light emitting element in accordance with image information, means for detecting a change in the emission wavelength of the semiconductor light emitting element or an amount having a change corresponding to the change in the emission wavelength; An image forming apparatus comprising: a comparing means for detecting that a value detected by the detecting means is equal to or greater than a predetermined value.