JP2000301764A - Laser exposing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a cost for modulating a laser beam. SOLUTION: This device comprises a red laser diode 60, a green laser diode 61 and a blue laser diode 62 for forming a color image on a photographic paper 1 by laser beams and a scanning means for scanning the laser beams across the photographic paper 1. The device further comprises a laser driving section for driving each of the laser diodes 60, 61, 62. The laser driving section directly modulates the laser diodes in accordance with image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a red laser light source, a green laser light source, a blue laser light source for forming a color image on a photographic photosensitive material by a laser beam, and the laser beam And a scanning means for scanning the laser beam.

[0002]

2. Description of the Related Art A laser beam has a sharp directivity so that a spot diameter can be narrowed, and a high-quality photograph is formed by scanning a laser beam on a photographic photosensitive material such as photographic paper. can do. In order to form a color image on a photographic material by exposure, a red, green, and blue laser light source is used to form an image using a laser beam by modulating a laser beam output from each laser light source with an acousto-optic device. Can be. The acousto-optic element generates an ultrasonic wave in the acousto-optic medium by supplying a high-frequency signal corresponding to image data to the piezoelectric element. The laser beam incident on the acousto-optic element is
Diffracted according to the frequency and magnitude of the high-frequency signal,
The acousto-optic element outputs a plurality of diffracted laser beams. An image can be formed on a photographic material by the laser beam thus modulated.

[0003]

However, red,
In order to modulate the green and blue laser beams, an acousto-optic device is required for each, and complicated control by a driver for driving each acousto-optic device is also required. In addition, when the laser beam is incident on the acousto-optic element, the narrower the beam diameter, the faster the modulation speed. Therefore, an optical system for narrowing the beam diameter is required. Therefore, the modulation by the acousto-optic element had to be expensive. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laser exposure apparatus capable of reducing a cost for modulating a laser beam.

[0004]

According to the present invention, there is provided a laser exposure apparatus for forming a color image on a photographic material using a laser beam, a green laser light source, and a blue laser light source. A laser light source, and scanning means for scanning the laser beam with respect to the photographic photosensitive material; and a laser drive unit for driving each of the laser light sources. It is characterized in that the light source is directly modulated.

According to this configuration, the laser light source itself is directly modulated instead of using an acousto-optic device to modulate the laser beam. Therefore, not only is the acousto-optic element unnecessary, but also an optical system for narrowing the beam diameter of the laser beam incident on the acousto-optic element becomes unnecessary. As a result, a laser exposure apparatus that can reduce the cost for modulating the laser beam can be provided.

[0006] In a preferred embodiment of the present invention, the laser light source is a laser diode. It is preferable to directly modulate the laser diode itself because the modulation speed can be increased. Further, by using a laser diode, the size of the light source unit can be reduced.

[0007] In another preferred embodiment of the present invention, the laser light source is a laser diode pumped solid-state laser. In the case of a laser diode-pumped solid-state laser, the modulation speed by the acousto-optic element is faster, but if the modulation rate can be slower in performance, the laser diode-pumped solid-state laser can be directly modulated. In addition, since an acousto-optical element is not required, the cost can be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a laser exposure apparatus 100 according to the first embodiment. FIG. 2 is a control block diagram of the laser exposure apparatus 100. <Configuration of Laser Exposure Apparatus According to First Embodiment> In FIG. 1, a laser exposure apparatus 100 is roughly provided with a laser light source section P1 and a laser scanning section P2.
The laser light source unit P1 includes an R light laser diode 60 functioning as a red laser light source, a G light laser diode 61 functioning as a green laser light source, and a B light laser diode 62 functioning as a blue laser light source.

The laser light source P1 is provided with a synthesizing means C for synthesizing each laser beam. The synthesizing means C includes a first mirror 25, a second mirror 26, and a third mirror 27 arranged in this order from the upper side of the optical path. The first mirror 25 reflects the red laser beam in a direction perpendicular to 90 degrees. The second mirror 26 is a dichroic mirror, and reflects the green laser beam in the direction perpendicular to 90 degrees and transmits the red laser beam reflected by the first mirror 25. The third mirror 27 is a dichroic mirror that reflects the blue laser beam in a direction perpendicular to the direction of 90 degrees and transmits the green laser beam reflected by the second mirror 26 and the red laser beam transmitted through the second mirror 26. Let it. That is, the third mirror 27
In the optical path on the lower side, the laser beams are combined.

<Structure of Laser Scanning Unit> The combined laser beam is a laser scanning unit (corresponding to a scanning unit).
Scanning is performed at P2. The laser scanning unit P2 includes a correction mirror 30, a polygon mirror 31, an fθ lens 32,
A mirror 33 for controlling a scanning start position and an optical sensor 34 for detecting a laser beam reflected from the mirror 33
And

The polygon mirror 31 is driven and controlled by a polygon driver 35, and rotates clockwise in FIG. 1 to scan a laser beam over photographic paper (corresponding to a photographic photosensitive material) 1 (main scanning). To form an image by exposure. If the polygon mirror 31 is tilted, the quality of the image is degraded.
0 is provided. The correction mirror 30 is driven by a piezoelectric element (not shown) in conjunction with the rotation of the polygon mirror 31. Note that the correction mirror 30 is a normal reflection mirror,
In the optical path between the reflection mirror and the polygon mirror 31,
An optical system including a cylindrical lens for correcting surface tilt may be provided.

The fθ lens 32 applies the laser beam deflected at an equal angular velocity by the polygon mirror 31 to the photographic paper 1.
The above is corrected so that the speed becomes constant. Thereby, the distortion is corrected. The printing paper 1 is driven in a direction perpendicular to the paper surface of FIG. 1, and a driving mechanism includes a driving roller 40 for nipping the printing paper 1.
, A pressure roller 41, a pulse motor 42 for driving the drive roller 40, and a motor driver 43.
While the photographic paper 1 is being conveyed in the sub-scanning direction, the main scanning of the laser beam in the laser
A digital image can be formed by exposure. The exposed photographic paper 1 is subjected to well-known development processing and drying processing, cut into prints, and discharged outside the apparatus.

<Control Block Diagram> FIG. 2 is a control block diagram. The scanner device S is a device for reading an image on the negative film 2, and includes a reading light source 3, an imaging lens 4, a CCD area sensor 5, and a negative film transport roller 6. The read image data is stored in the image data storage unit 3 of the laser exposure apparatus 100.
6 and stored. The scanner device S may be integrated with the laser exposure device 100, or may be a device that is separate and independent from the laser exposure device 100. As the image data stored in the image data storage unit 36, data stored in the digital camera 7, the floppy (registered trademark) disk 8, and the CD-ROM 9 may be taken.

The system controller 37 controls the operation of each part of the laser exposure apparatus 100.
Shows the main functions. Image data storage unit 36
Is sent to the R light laser driver 63, the G light laser driver 64, and the B light laser driver 65 to generate a signal (drive voltage signal) for modulating the laser beam. Each of these laser drivers 63, 64, 65 functions as a laser driver. Thus, each of the laser diodes 60, 61,
Since it is configured to directly modulate 62, it is not necessary to provide an acousto-optic element, and cost reduction can be achieved. The correction mirror driver 39 drives the correction mirror 30 in synchronization with the rotation of the polygon mirror 31, and corrects the surface tilt. Further, the system controller 37 controls the main scanning start position based on a signal from the optical sensor 34.

<Configuration of Laser Exposure Apparatus According to Second Embodiment> Next, a laser exposure apparatus 100 according to a second embodiment will be described with reference to FIG. The difference in configuration from the first embodiment is that instead of using a laser diode as a laser light source, an R light laser diode pumped solid-state laser is used.
(Hereinafter, abbreviated as LD pumped solid laser.)
It is provided with a G light LD pumped solid laser 11 and a B light LD pumped solid laser 12.

Next, the structure of the LD-pumped solid-state laser will be briefly described with reference to FIG. The R-light and G-light LD-excited solid-state lasers 10 and 11 have the same structure. The LD excitation solid laser 12 includes a laser diode 50 as an excitation light source, a condenser lens 51, a laser medium 52, an SHG element (light wavelength conversion element) 53, and an output mirror 54. Peltier elements 55 and 56 for temperature control are provided near the laser diode 50 and the SHG element 53. Laser medium 5
The laser resonates between the second end face 52a and the output mirror 54, and a laser beam is output.

When the laser beam of the LD-excited solid-state laser is modulated, if the modulation is performed directly without using an acousto-optic element, the modulation speed becomes slow. However, in the case of scanning at a low speed as in the case of photographic paper 1 called digital paper, even if a configuration in which direct modulation is performed using an LD-excited solid-state laser is employed, it is sufficiently practical. A control block diagram in the case of using the LD-pumped solid-state laser can operate in the same manner as in FIG.

<Another Embodiment> A gas laser may be used as a laser light source.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a laser exposure apparatus according to a first embodiment.

FIG. 2 is a control block diagram of the laser exposure apparatus according to the first embodiment.

FIG. 3 is a schematic diagram illustrating a configuration of a laser exposure apparatus according to a second embodiment.

FIG. 4 is a diagram showing a structure of an LD-pumped solid-state laser.

[Description of Signs] 1 Photographic paper 10 R light LD pumped solid laser 11 G light LD pumped solid laser 12 B light LD pumped solid laser 60 R light laser diode 61 G light laser diode 62 B light laser diode 63 R light laser driver 64 G light laser driver 65 B light laser driver 100 Laser exposure device P1 Laser light source P2 Laser scanning

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/04 H04N 1/04 D 1/113 104A F-term (Reference) 2C362 AA03 AA12 BA66 CA40 CB71 DA09 2H106 AA71 BH00 5C072 AA03 BA02 BA19 HA02 HA06 HA13 HB01 HB06 QA14 5F072 JJ01 KK05 KK12 KK30 MM03 PP07 QQ02 5F073 AB25 AB27 AB29 BA07 GA24

Claims (3)

[Claims] 1. A red laser light source, a green laser light source, and a blue laser light source for forming a color image on a photographic photosensitive material by a laser beam, and scanning means for scanning the photographic photosensitive material with the laser beam. A laser exposure device comprising: a laser drive unit that drives each of the laser light sources,
The laser drive unit directly modulates each of the laser light sources based on image data. 2. The laser exposure apparatus according to claim 1, wherein the laser light source is a laser diode. 3. The laser exposure apparatus according to claim 1, wherein the laser light source is a laser diode-pumped solid-state laser.