JP3454353B2 - Laser exposure equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is constructed so that a laser beam from a laser light source is irradiated onto a recording medium through a polygon mirror mechanism and is scanned to form an image by exposure.
The polygon mirror mechanism relates to a laser exposure apparatus in which a polygon mirror rotation driving unit in which polygon mirrors are linked and linked is supported and linked to a support frame.

[0002]

2. Description of the Related Art In a polygon mirror mechanism of a laser exposure apparatus of this type, the rotation speed of the polygon mirror is, for example, 4
Although it covers a wide range of 500 rpm to 13000 rpm, conventionally, one polygon mirror mechanism has been made to correspond to the wide range of rotation speed.

[0003]

However, from the time of low speed operation of about 4500 rpm, 13,000 rp
It is difficult to configure the rotation axis of one polygon mirror mechanism so as not to swing during a high-speed operation of about m. Therefore, in the above conventional configuration, the manufacturing cost per polygon mirror mechanism is high and the yield is high. There was a problem that was worse.

Even if the polygon mirror mechanism as described above is manufactured at a high cost, the rotation axis is easily shaken at the low speed side or the high speed side to make the rotation unstable, and the surface of the polygon mirror is tilted. As a result, there is a problem that the image quality of the image formed on the recording medium deteriorates.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the manufacturing cost per polygon mirror mechanism, improve the yield, and prevent the surface of the polygon mirror from collapsing. This is to suppress the deterioration of the image quality of the image formed on the recording medium.

[0006]

The constitution, operation and effect of the invention according to claim 1 are as follows.

[Structure] In the laser exposure apparatus described at the beginning, the position of the optical axis
For the purpose of determination, the connecting portion of the support frame to the polygon mirror rotation driving portion and the connected portion of the polygon mirror rotation driving portion to the connecting portion of the support frame have a positioning portion and a positioned portion with respect to the mating side. Are formed separately, and the connected portion and the positioned portion are formed in a rotation driving portion of a polygon mirror mechanism that is separate from the polygon mirror mechanism, thereby forming the separate polygon mirror mechanism in the support frame. The polygon mirror mechanism on the side of the connecting portion can be exchangeably connected to the connecting portion.

[Operation] [a] For example, a plurality of low-speed / medium-speed / high-speed polygon mirror mechanisms are configured to match the respective speeds, and the low-speed polygon mirror mechanism is used during low-speed operation. A polygon mirror mechanism for medium speed is operated during high speed operation, and a polygon mirror mechanism for high speed is operated during high speed operation by separately supporting and connecting to a supporting frame.

[B] Specifically, one of the plurality of polygon mirror mechanisms is mounted on the support frame via the positioning portion on the support frame side and the positioned portion on the polygon mirror rotation drive side. The polygon mirror rotation driving unit is connected to the connected portion of the support frame in that state.

This makes it possible to prevent the deviation of the optical axis due to the replacement of the polygon mirror mechanism.

As the structure of the low-speed / medium-speed polygon mirror mechanism, for example, a ball bearing can be adopted as the bearing of the rotary shaft, and a small-output or medium-output rotary drive section can be adopted. As the structure of the polygon mirror mechanism for high speed, a pneumatic bearing can be adopted as the bearing of the rotary shaft, and a high output rotary drive unit can be adopted.

[C] It is difficult to configure the rotation axis of one polygon mirror mechanism so as not to swing at low speed, medium speed, and high speed, and the manufacturing cost per unit increases and the yield decreases, resulting in cost increase. Although there is a problem that the rotation axis of the polygon mirror mechanism easily shakes even if manufactured by the above, according to the configuration of claim 1, the above [a],
As described in [b], since the plurality of polygon mirror mechanisms for low speed, medium speed, and high speed are constructed in a structure adapted to each speed, the above problems can be avoided.

[0013] Even when the low speed (or medium / high speed) polygon mirror mechanism is replaced with another low speed (or medium / high speed) polygon mirror mechanism when [d] maintenance is required, the polygon mirror mechanism By exchanging and connecting the mechanism to the support frame as in the above [a] and [b], it is possible to prevent the deviation of the optical axis due to the exchange of the polygon mirror mechanism.

[Effect] Therefore, the manufacturing cost per unit of the polygon mirror mechanism can be reduced, the yield can be improved, the workability of the maintenance work can be improved, and the collapse of the surface of the polygon mirror can be suppressed. As a result, it is possible to suppress the deterioration of the image quality of the image formed on the recording medium.

[0015]

[Configuration] In the invention according to claim 1 , further, the connected portion is configured by providing a mounting seat on the polygon mirror rotation driving portion, and the connecting portion forms a support seat for the mounting seat on the support frame. The positioning target portion and the positioning portion are configured such that a convex corner portion and a concave corner portion that fit with each other are formed separately on the mounting seat and the support seat.

[Operation] [f] In addition to the same operation as the operation according to the first aspect, the following operation can be performed.

[G] Concave corners (or convex corners) of the support seat provided on the support frame side and the convex corners (or concave corners of the mounting seat provided on the polygon mirror rotation drive side). Corner part) to position any one of the plurality of polygon mirror mechanisms with respect to the support frame, and in that state, attach the polygon mirror rotation drive part to the support seat on the support frame side. Connect the seats.

[Effect] Therefore , since the positioning portion and the positioned portion are formed by the mere convex corner portion and the concave corner portion, the positioning structure can be simplified. Further of the present invention
As a configuration, a sushi is installed on the top of the concave corner.
Preferably.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a laser exposure apparatus 100. The laser exposure apparatus 100 includes a laser light source unit P1.
The laser beam from the laser light source is applied to the photographic printing paper 1 (corresponding to a recording medium) via the polygon mirror mechanism 31 to scan the photographic printing paper 1 to form an image by exposure.

The laser light source portion P1 includes an R light laser diode 10 functioning as a red laser light source, a G light laser diode pumped solid state laser (hereinafter abbreviated as LD pumped solid state laser) 11 functioning as a green laser light source. , B light LD that functions as a blue laser light source
Excitation solid-state laser 12 and R light laser diode 10
R photoacoustic optical element that modulates the R laser beam output from the device (hereinafter, the acoustooptical element is abbreviated as AOM) 1.
3 and a G light AOM 14 for modulating the G laser beam,
B light AOM15 for modulating the B light laser beam and each A
R-light AOM driver 16, G-light AOM driver 17, and B-light AOM that drive the OMs 13, 14, and 15, respectively.
And a driver 18.

R light laser diode 10, G light, B light LD-pumped solid state lasers 11 and 12, and respective AOMs 13 and 1
Condensing lens 19, 20, 2 in the optical path between
1 is provided to narrow the beam diameter incident on each AOM 13, 14, 15. The modulation speed can be increased by narrowing the beam diameter.

The blue laser beam incident on the B-light AOM 15 is diffracted in accordance with the frequency and amplitude of the high frequency signal from the B-light AOM driver 18, and the B-light AOM 15 is diffracted.
15 outputs a plurality of diffracted blue laser beams. A B light shielding plate 24 is provided on the lower side of the optical path of the B light AOM 15 and has the highest intensity of the diffracted light.
Only the second-order diffracted light passes.

As described above, the B-light AOM driver 18 generates a high-frequency signal corresponding to the image data, and supplies this high-frequency signal to the B-light AOM 15, whereby the blue laser beam is optically modulated corresponding to the image data. Can be made.

The above points are the same for the other AOMs 13 and 14, and like the B light shielding plate 24, the R light shielding plate 2
2, G light shield plate 23 is provided.

The laser light source portion P1 is provided with a combining means C for combining the laser beams. The synthesizing unit C includes a first mirror 25, a second mirror 26, and a third mirror 27, which are sequentially arranged from the upper side of the optical path.

The first mirror 25 reflects the red laser beam at a right angle. The second mirror 26 is a dichroic mirror, which reflects the green laser beam in a right angle direction and transmits the red laser beam reflected by the first mirror 25.

The third mirror 27 is a dichroic mirror, which reflects the blue laser beam in the perpendicular direction and transmits the green laser beam reflected by the second mirror 26 and the red laser beam transmitted through the second mirror 26. Let That is, the laser beams are combined in the optical path on the lower side of the third mirror 27.

As described above, the blue laser beam is combined by the third mirror 27 arranged on the lowermost side in the combining means C. In other words, it has the least chance (number of times) to act on the mirror as compared with the red and green laser beams. Therefore, the power of the blue laser beam, which is the least output, can be effectively utilized.

[Structure of Laser Scanning Section] The combined laser beam is scanned by the laser scanning section P2. The laser scanning unit P2 includes a correction mirror 30, a polygon mirror mechanism 31, an fθ lens 32, a scanning start position control mirror 33, and an optical sensor 34 that detects a laser beam reflected from the mirror 33. ing.

As shown in FIG. 2, the polygon mirror mechanism 31 supports and connects an electric motor M (corresponding to a polygon mirror rotation driving section) in which the polygon mirror 2 is interlockingly connected to the support frame 3 via bolts. Configured. Then, the driving is controlled by the polygon driver 35, and
By rotating in the clockwise direction, the laser beam is scanned (main scanning) on the printing paper 1 to form an image by exposure.
The polygon mirror mechanism 31 is for low speed 4500 rpm
To rotate.

The connecting structure of the electric motor M and the support frame 3 will be described.
(Corresponding to the connected portion) and the supporting frame 3
Is provided with a support seat 5 (corresponding to a connecting portion) for the mounting seat 4, and the mounting seat 4 is provided with a convex corner portion 6 (see FIG. 3) as a positioned portion for the support seat 5 to support the support seat 5. By forming a concave corner portion 7 (see FIG. 3) as a positioning portion for the mounting seat 4 on the seat 5 and fitting both corner portions 6 and 7, the electric motor M is mounted on the support frame 3. It is structured so that it can be positioned.

Further, with the above structure, a medium speed or high speed (1300) separate from the polygon mirror mechanism is provided.
An electric motor of a polygon mirror mechanism (not shown) at 0 rpm is provided with the mounting seat and the convex corner portion is formed, so that the separate polygon mirror mechanism is provided on the support frame 3 for the low speed. It is configured to be interchangeable with the polygon mirror mechanism.

The medium-speed polygon mirror mechanism and the high-speed polygon mirror mechanism have a structure (output of electric motor, bearing structure, etc.) adapted to each speed. This makes it possible to fit and position both corners, and prevent deviation of the optical axis due to replacement of the polygon mirror mechanism.

Even when the low speed (or medium / high speed) polygon mirror mechanism is replaced with another low speed (or medium / high speed) polygon mirror mechanism when maintenance becomes necessary, the polygon mirror mechanism may be replaced by the above-mentioned one. By exchanging and connecting to the support frame 3 as described above, it is possible to prevent the deviation of the optical axis due to the exchange of the polygon mirror mechanism.

The correction mirror 30 corrects the surface tilt of the polygon mirror 2 and suppresses the deterioration of image quality. The correction mirror 30 is a piezoelectric element in conjunction with the rotation of the polygon mirror 2.
Driven by (not shown). The correction mirror 30 may be an ordinary reflection mirror, and an optical system composed of a cylindrical lens or the like for surface tilt correction may be provided in the optical path between the reflection mirror and the polygon mirror 31.

The fθ lens 32 projects the laser beam deflected at a constant angular velocity by the polygon mirror 31 onto the photographic paper 1.
Correct so that the speed is constant. This corrects the distortion aberration. The photographic printing paper 1 is driven in a direction perpendicular to the paper surface of FIG. 1, and the drive mechanism is a drive roller 40 that holds the photographic printing paper 1 between them.
, A pressure roller 41, a pulse motor 42 for driving the drive roller 40, and a motor driver 43.
While carrying the photographic printing paper 1 in the sub-scanning direction, by the main scanning of the laser beam in the laser scanning section P2,
Digital images can be exposed and formed. The exposed photographic printing paper 1 is subjected to well-known development processing and drying processing, cut into prints, and then discharged to the outside of the apparatus.

[0039]

The present invention can be applied to a copying machine (in this case, the recording medium is a photosensitive drum of the copying machine).

[Brief description of drawings]

FIG. 1 is a schematic diagram of a laser exposure apparatus.

FIG. 2 is a vertical sectional view of a polygon mirror mechanism.

FIG. 3 is a diagram showing a connecting structure of a polygon mirror mechanism and a support frame.

[Explanation of symbols]

1 recording medium 2 polygon mirror 3 Support frame 4 Connected part 5 connection 6 Positioned part 7 Positioning part 31 Polygon mirror mechanism M polygon mirror rotation drive unit

Claims (2)

(57) [Claims] 1. A structure in which a laser beam from a laser light source is irradiated onto a recording medium through a polygon mirror mechanism and scanned to form an image by exposure, and the polygon mirror mechanism is a polygon mirror rotation in which polygon mirrors are linked and linked. A laser exposure apparatus comprising a drive unit supported and connected to a support frame, wherein the support frame is connected to the polygon mirror rotation drive unit for positioning the optical axis, and the polygon is connected to the connection unit. In the connected part of the mirror rotation drive part,
By separately forming a positioning part and a positioned part for the other side, and forming the connected part and the positioned part in the rotation driving part of the polygon mirror mechanism different from the polygon mirror mechanism, the separate polygon mirror mechanism connecting portion of the supporting frame, the connecting portion side polygon mirror mechanism and the exchange coupleable to constitute of the object connection portion Replacing the polygon mirror rotary drive unit
A mounting seat is provided, and the connecting portion is opposed to the mounting seat.
A support seat to be installed on the support frame.
The positioning part and the positioning part are the mounting seat and the support seat.
A convex corner and a concave corner that fit together.
A laser exposure apparatus that is configured by distributing and forming the laser section. 2. A slime is provided on the top of the concave corner portion.
The laser according to claim 1, wherein the laser is provided.
Exposure equipment.