JPH0542716A - Image forming device using light beam - Google Patents

Abstract

PURPOSE:To realize a recording device wherein reproducibility of gradation property is improved by scanning first and second light beams of which one has image information, in such a manner that each beam is superposed on a moving photosensitive body after a lapse of time. CONSTITUTION:An image data signal sent from an image data memory 7 is sent to a laser drive circuit 10A and a line buffer 8, and is delayed at a delay circuit 9 by a predetermined time T and sent to a laser drive circuit 10B. The laser drive circuit 10B makes an image based on the image data memory 7 emitted by a semiconductor laser 1 at a timing different by the predetermined time T. On a photosensitive material 5, the same information is exposed on the same point twice by deviating the timing by the predetermined time T at the delay circuit 9. Thus, by recording the same image information twice on the photosensitive material 5, laser outputs of a first image record and a second image record are made to be different from each other, so that gradation property can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus for recording a light image by relatively scanning light of a minute spot on a photosensitive member which is a recording medium.

[0002]

2. Description of the Related Art Conventionally, an optical recording device for recording an optical image by relatively scanning a light beam of a minute spot on a recording medium is LB.
P, an optical printer for plate making, etc. are known.

These recording devices have the advantages of higher resolution and higher speed recording than those of heat recording devices such as thermal recording devices. Further, the sensitivity of a photosensitive material such as a silver salt material, a resist material, a sublimable material, or an electrophotographic material is lower than that in normal exposure when exposed in a very short time even if the exposure amount is the same. There is a property.

Therefore, in the above-mentioned conventional example, especially 10 ^-8 to 10
^When high-speed recording of ^-7 sec / dot is performed, the sensitivity is lowered due to the high brightness and short time reciprocity failure of the photosensitive material, and a light source of high power is required.

Further, in the above-mentioned conventional example, in order to reproduce the gradation, the output light amount of the light source has to be changed in multiple steps for each dot. Especially, in the case of a semiconductor laser, the output light amount is delicately controlled. It was very difficult.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to enable a recording apparatus having an improved gradation reproducibility.

[0007]

SUMMARY OF THE INVENTION The present invention which achieves the above object is an image recording apparatus for forming a recorded image by irradiating a photoconductor with a light beam, the photoconductor being driven and the photoconductor. An optical means for irradiating a light beam, the first beam and the light source means for forming the second beam, and at least one of which is light having image information. And a light beam scanning unit that scans each of the light beams of the beam and the second beam so that the beams overlap with each other on the moving photosensitive member with a time interval.

[0008]

EXAMPLES The present invention will be described below with reference to examples.

(Embodiment 1) FIG. 1 is a schematic overall view of an optical recording apparatus according to the present invention.

In the figure, 1 is a semiconductor array for generating a laser beam, 2 is a first optical system consisting of a collimator lens and a cylindrical lens, 3 is a polygon mirror, and 4 is an F.
A θ lens (hereinafter referred to as a second optical system) 5 is a sheet-shaped dry silver salt photosensitive material corresponding to a semiconductor laser, and moves at a constant speed in a direction perpendicular to the drawing.

The two laser beams 6A and 6B emitted from the semiconductor array 1 pass through the first optical system, are reflected by the polygon mirror 3, and are reflected by the polygon optical mirror 3 onto the photosensitive material 5 via the second optical system. The same main scanning line is irradiated at positions separated from each other by about 1 mm in the main scanning direction. The beam diameter was 20 μm in the main scanning direction and 40 μm in the sub-scanning direction so as to form an image having an elliptical beam diameter, and the recording surface of the photosensitive material was scanned at 100 ns / dot. By adopting such a scanning method, recording can be performed with a recording energy of up to 125 μJ / cm ² by a laser having an output of 5 mw (milliwatt) on the recording surface.

FIG. 2 shows a block diagram for driving a semiconductor laser. The image data signal sent from the image data memory 7 is sent to the laser drive circuit 10A and the line buffer 8. The image data signal sent to the line buffer 8 is delayed by the delay circuit 9 for a predetermined time T and sent to the laser drive circuit 10B. The laser driving circuit causes the semiconductor laser 1 to emit an image based on the image data memory at different timings for a predetermined time T, and the same information on the photosensitive material 5 is shifted by a delay circuit for a predetermined time T to obtain the same information. Imagewise exposure.

Here, the predetermined time T is obtained as T = χ / υ depending on the scanning speed υ of the laser beam 6 scanning the photosensitive material 5 and the distance χ between the laser beams 6A and 6B on the photosensitive material. Here, T≈5 μS.

By thus recording the same image information twice on the photosensitive material 5, the first or second image recording serves as an optical bias for the high-luminance and short-time reciprocity law failure of the photosensitive material. With a single laser, a sensitivity of 100 μJ / cm ²
The recording with the two overlapping laser beams enables recording at 80 μJ / cm ² . By making the laser outputs of the first image recording and the second image recording different, it was possible to improve the gradation. The effect is obtained.

(Embodiment 2) FIG. 3 shows a schematic view of another embodiment of the present invention.

In this embodiment, two kinds of semiconductor lasers having different wavelengths are horizontally arranged side by side, and the same driving as in Embodiment 1 is performed. Here, the wavelength of the first laser 6A is made to correspond to the absorption wavelength of the sensitizing dye of the silver salt photosensitive material (83
0 ^nm ), and the wavelength of the second laser 6B was made to correspond to the intrinsic silver sensitivity wavelength of the silver salt photosensitive material by SHG (415 ^nm ).

By setting the wavelength as described above and driving it by the drive circuit of FIG. 2, the image recording by the second laser 6B is light for the high brightness short time reciprocity law failure of the silver salt photosensitive material which is the photosensitive material. It plays the role of bias and can further reduce the output power than halving the laser output power. The effect is obtained.

(Embodiment 3) FIG. 4 shows a schematic view of still another embodiment of the present invention.

In this embodiment, the semiconductor laser is displaced in the direction of the optical axis so that the image forming point of only the first laser beam 6A is on the photosensitive material 5, and the driving of FIG. Driving was performed using a circuit.

By setting the semiconductor laser as described above, by shifting the image forming point of the second laser from the photosensitive material, the beam diameter of the laser light is made different, and it serves as an optical bias and has a high brightness and a short brightness. Time reciprocity failure can be reduced. By recording an image with two kinds of lasers having different beam diameters, an image with high gradation can be obtained.
The effect is obtained.

In the third embodiment, the aberration of the optical system may be corrected with respect to the wavelength of the first laser to make the image forming aperture of the second laser substantially different from the image forming aperture of the first laser. It is possible.

Further, in the embodiment of the present invention, the case where the semiconductor lasers are arranged in the main scanning direction of the light beam has been described, but it goes without saying that they may be arranged in the sub scanning direction.

Since the same information is written by two lasers, the ratio of the beam diameters is set within 10 times so that the fog does not adversely affect the image quality in order not to reduce the resolution. Alternatively, it is an effective method to weaken the laser output of the large-diameter beam to the extent that fog does not occur.

According to each of the above-mentioned embodiments, in the optical recording apparatus for recording an optical image by deflecting and scanning a plurality of minute light beams, the recording time is made different based on the same image data and repeated a plurality of times. Since the recording is performed as described above, it is possible to eliminate the reciprocity law failure of high brightness for a short time and to easily perform the gradation control.

(Embodiment 4) FIG. 5 shows a block diagram for driving a semiconductor laser, which is different from the configuration shown in FIG.
With the same configuration as described in the first embodiment, only the laser driving method was changed. In this embodiment, the image data signal sent from the image data memory 7 is sent to the laser driving circuit 10A, and the laser beam 6A exposes the recording surface corresponding to the image data signal for a recording image.

A laser emission control signal is sent from the laser emission control circuit 11 to the laser drive circuit 10B so that the entire image area is uniformly exposed, and the laser beam 6B is emitted.
Bias exposure is performed on the recording surface.

Here, the laser beam 6A on the recording surface,
As described in the first embodiment, the scanning by 6B has a timing difference of T = χ / υ from the distance χ of both beams on the recording surface and the scanning speed υ of the laser beam 6. The light intensity of the laser beam 6B is set so as not to cause fogging in the final image formed by this photosensitive material.

As described above, the image exposure by the fine spots and the bias exposure by the fine spots are overlapped on the photosensitive material 5 to reduce the high-luminance and short-time reciprocity law failure of the photosensitive material by the bias light. At the same time, the effect that the γ characteristic of image exposure can be controlled by changing the intensity of the bias light is obtained.

(Embodiment 5) In this embodiment, as a modification of the structure of the second embodiment, one of two laser beams is subjected to bias exposure and two semiconductor lasers having different wavelengths are used.
The types were horizontally arranged side by side, and overlapping exposure was performed by the same drive as in Example 4 above.

Here, as in the second embodiment, the wavelength of the laser for image exposure is made to correspond to the absorption wavelength of the sensitizing dye of the silver salt photosensitive material (830 ^nm ), and the wavelength of the laser for bias exposure is SHG. Was made to correspond to the silver specific sensitivity wavelength of the silver salt photosensitive material (415 ^nm ).

By setting the wavelength as described above, the reciprocity law failure can be reduced and the gradation can be improved as in the other embodiments.

(Embodiment 6) In this embodiment, two semiconductor lasers having the same wavelength are displaced in the optical axis direction by using the structure of the embodiment described in FIG. 4 so that the image exposure laser image forming point is on the photosensitive material. In the same manner as in Example 4, the driving based on the image data memory and the driving based on the uniform exposure not including this data were performed in the state of being arranged so as to come to the end.

By setting the semiconductor laser as described above, the image forming point of the bias light laser is shifted from the photosensitive material to widen the beam diameter of the laser light, thereby performing the function of optical bias many times and achieving high brightness. The effect that the reciprocity law failure for a short time can be reduced and an image with high gradation can be obtained is obtained.

In the fifth embodiment, the aberration of the optical system is corrected with respect to the first laser wavelength so that the image forming aperture of the second laser is substantially different from the image forming aperture of the first laser. Is also possible. Also, in the fourth and subsequent embodiments, the case where the semiconductor lasers are arranged in the main scanning direction of the light beam has been described, but of course they may be arranged in the sub scanning direction.

As described above, according to this embodiment, an optical image corresponding to image data is recorded while deflecting and scanning at least one minute light beam, and at least one other minute light beam is recorded. High-luminance and short-time reciprocity law failure can be eliminated and gradation control can be performed easily by performing deflection scanning while continuously emitting light in the image area. By thus performing a plurality of exposures within the same optical system, it is possible to configure a small device without the need to newly arrange an illuminating device. It is also advantageous in terms of light shielding.

Next, one embodiment of a dry silver salt apparatus to which the above embodiment can be applied will be described with reference to FIG.

FIG. 6 is a schematic cross-sectional view of a device 12 to which the light beam irradiation method of the present invention can be applied.
0, image exposure unit 21, heat development unit 23, entire surface exposure unit 24,
It is composed of a transfer unit 25 and a paper discharge unit 26. Each will be explained in turn.

1) Paper Feeding Unit 20 In the paper feeding unit 20, a photoconductor cartridge 32 accommodating a photosensitive material roll 31 around which the photoconductor 5 is wound is detachably provided. At the outlet of the photoconductor cartridge 32, a pair of feeding rolls 33a and 33b are arranged, whereby the photoconductor is fed by a fixed length. Next, the photoconductor that has been ejected for a certain length is cut by the cutter unit 34.

2) Image exposure unit 21 The photoconductor 1 conveyed from the paper feed unit 20 is imagewise exposed by the scanning exposure means 35 with a laser beam for performing image exposure on the photoconductor 5 by scanning according to the above embodiment. 36 is an exposure support for stably exposing the above exposure.

3) Heat developing section 23 The imagewise exposed photoreceptor 1 is sent to the heat developing section 23 by the conveying rollers 40a and 40b, and is nipped by the heating roll 41 and the roll support 42, and is developed at about 120.degree. To be done. The heat source has a halogen heater 43 inside the heating roll 41.

4) Full exposure 24 The developed photoconductor 5 is sent to the full exposure section 24 by the transport roller 44. The entire surface exposure section 24 includes a light source 45, a light source guide 46, a heating plate 47, and a conveyor belt 48.

5) The transfer portion 259 is an image receptor and is housed in a removable image receptor cartridge 49. The image receiving body 13 delivered by the delivery roll 50 from the image receiving cartridge 49 is sent to the conveyance guide 51 and the transfer rollers 52 and 53.

On the other hand, the photosensitive member 5 is sent to the transfer rollers 52 and 53 by the carrying roller 54 and the carrying guides 55 and 56 from the whole surface exposure section 24 through the above steps. Image receptor 13 and photoconductor 5
Are sent to the transfer unit 25 and superposed at a predetermined position. The transfer rollers 52 and 53 are heated by the halogen heaters 57 and 58 arranged inside the transfer roller on the image receiving member 13 and the photosensitive member 5 which are superposed as described above, and diffuse the diffusible dye from the photosensitive member 5 on the image receiving member. Form a color image. The transfer temperature at this time is 70 to 170 ° C., preferably 100.
C. to 150.degree. C., more preferably 100 to 130.degree.

6) Discharging unit 26 Next, the photosensitive member 5 and the image receiving member 9 are separated by the separation claw 59, and then sent to the discharging trays 60 and 61.

An example of a photosensitive member which is a photosensitive material used in this apparatus will be described with reference to FIG.

FIG. 7 schematically shows an enlarged cross-sectional view of the photosensitive member. The photosensitive member 5 is a resin film 102 made of polyester, polycarbonate, polyimide, aromatic polyamide or the like, and trimethylolpropane on the resin film. Monoacrylate 103A such as triacrylate and dipentyristol hexaacrylate, cleavage type such as benzyl dimethyl ketal, hydrogen abstraction type photopolymerization initiator 103B such as a combination of diethylthioxanthone and ethyl dimethylamine benzoate, styryl type, anthraquinone type, Polymerized layer 103 containing thermal diffusion dye 103C such as indoaniline and reduction of 1-naphthol, 2.2′-methylenebis (alkylphenol), 4.4′-methylenebis (alkylphenol), etc. Agent 104A
And a surface photosensitive layer 104 containing a photosensitive silver halide 104B such as silver bromide, silver iodobromide or silver chlorobromide, and an organic silver salt 104C such as silver behenate or silver benzotriazole. Is configured. In the above description, the case where the polymerized layer and the photosensitive layer are separated is illustrated, but both layers may be the same layer. Further, the photosensitive layer 104 may contain a sensitizing dye such as cyanine or merocyanine having an absorption wavelength for the information light to be irradiated.

Here, an example having a dry silver salt layer and a polymerized layer was shown as a photoreceptor, but the effect according to the present invention can be obtained only with the dry silver salt layer.

The photosensitive material is not limited to the dry silver salt medium, but can be applied to general silver salt photosensitive medium, resist material, sublimation recording material and the like.

[0049]

According to the present invention, the sensitivity can be substantially increased even with a light source having a spot with a small output, so that the recording speed can be improved. Further, according to the light irradiation method of the present invention, the gradation reproducibility can be improved and the image quality can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an optical recording device according to an embodiment of the present invention.

FIG. 2 is a block diagram of an electric circuit for optical scanning according to an embodiment.

FIG. 3 is an explanatory diagram of an optical recording device according to another embodiment of the present invention.

FIG. 4 is an explanatory diagram of an optical recording device according to another embodiment of the present invention.

FIG. 5 is a block diagram of an electric circuit for optical scanning according to another embodiment.

FIG. 6 is a device sectional view showing an example of a recording device to which the present invention is applicable.

FIG. 7 is a schematic diagram showing a partially enlarged photoconductor used in this apparatus.

[Explanation of symbols]

 1 Semiconductor Array 5 Photosensitive Material 6A Laser Light 6B Laser Light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03C 5/08 8910-2H G03F 7/20 7818-2H G03G 15/04 116 9122-2H H04N 1 / 04 104 A 7251-5C 1/23 103 B 9186-5C (72) Inventor Tetsuro Fukui 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (1)

[Claims] 1. An image recording apparatus for forming a recorded image by irradiating a photoconductor with a light beam, comprising a driven photoconductor and optical means for irradiating the photoconductor with the light beam. Beam, and a light source means for forming a second beam, and at least one of the first and second light beams from the light source means is light having image information. A light beam scanning means for scanning the moving photosensitive member so that the respective beams overlap with each other at a certain time.