JPS6250713A - Recording device - Google Patents

Abstract

PURPOSE:To incorporate a mirror and a lens in a device securely without using any screw by pressing and fixing the lens and mirror to a supporting member with a frame-shaped spring plate. CONSTITUTION:A semiconductor laser 2 emits a laser beam modulated corresponding to a recording signal and the beam is collimated by a collimator lens incorporated in front of it into parallel light, which is made incident on a polygon mirror 14 as a laterally linear beam through the cylindrical lens 5 and mirror 10 which are held and fixed by spring plates respectively. This beam passes through an ftheta assembly 16 and a cylindrical lens 21 and is reflected downward by the mirror 29 to strike on the photosensitive surface of a photosensitive drum through a dust-protective glass. The photosensitive drum moves in the axial direction of the drum base, so the incident beam scans the drum to record characters and images on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording device such as a laser printer that records characters and images using an optical method.

[Prior art]

2. Description of the Related Art As a recording device using an optical system, there is a laser printer that scans a beam modulated by a recording signal to expose a photoreceptor and records thereon.

This laser printer consists of an optical scanning section that uses an optical deflection means to wave a beam modulated as described above, that is, performs main scanning, and a process section that records, develops, transfers, and fixes images on a photoreceptor using the main scanning beam. The beam is guided to the deflection means (in the middle of the optical path, there is a mirror for changing the optical path, a lens for giving a predetermined aperture to the beam, and making it incident on the deflection means). Ru.

Conventionally, these mirrors and lenses have been integrated into an assembly using screws, etc., and fixed to the board, but the assembly method using screws has poor workability and also requires a large number of parts. However, the cost has also increased, creating a problem in terms of cost.

[Purpose of the invention]

An object of the present invention is to provide a recording device in which mirrors and lenses can be reliably incorporated without using any screws.

[Structure of the invention]

For this reason, in the present invention, the lens and/or mirror are configured to be pressed and fixed to the support member using a frame-shaped spring plate.

〔Example〕

Examples of the present invention will be described below. FIG. 1 is a diagram showing the top surface of the optical system. The substrate is a substrate, on the top of which a beam main scanning system is constructed, and on the bottom surface a photoreceptor drum is provided.

A semiconductor laser 2 emits a laser beam modulated according to a recording signal. Note that a collimating lens for converting the emitted beam into parallel light is built into the emission aperture of the semiconductor laser 2. Reference numeral 3 denotes a holder for holding the semiconductor laser 2, which is fixed to the adjustment section 1a of the substrate 1.

4 is a cylindrical lens assembly that assembles a cylindrical lens 5 to make the incident beam into a narrower single horizontal beam; The position of the adjustment portion 1a can be adjusted in the direction of the arrow a along the adjustment portion 1a.

The cylindrical lens 5, as shown in FIG.
It is fitted into a recess 6b formed on the beam incidence surface of the rising part 6a of the holder 6, and the fitted state is held by a black frame-shaped spring plate 8.

Incidentally, a through hole (not shown) through which the beam passes is naturally formed in the upright portion 6a of the holder 6. Spring plate 8
consists of a U-shaped frame on the top surface, and the cylindrical lens 5
A window hole 8a through which the beam passes is formed in the front surface that presses down, that is, the central piece, and two pressers that press the back surface of the rising part 6a are formed at the opposite ends of the side pieces on both sides of the central piece. A piece 8b is formed.

This assembly 4 is capable of supporting its holder 6 with screws in any one of a plurality of pairs of screw holes 1b formed in advance in the adjustment section 1a of the substrate 1. , the distance from the semiconductor laser 2 can be adjusted by selecting the screw hole 1b.

, 9 is Mira 1 for bending the course of the beam by 90 degrees.
0, and its entirety is supported by a holder 11 to a substrate 1.

As shown in FIG. 3, the mirror 10 of the holder 11 is fitted into a recess 11b formed on one surface of its upright portion tta, and the mirror 10 is held in the fitted state by a spring plate 12. This spring plate 12 has the same color and shape as the spring plate 8 described above except for the rectangular window hole 12a that exposes the front surface of the mirror 9, so the details will be omitted.

13 is a printed wiring board on which a circuit for driving the semiconductor laser 2 described above is constructed.

14 is a polygon mirror with six reflective surfaces. Reference numeral 15 denotes a printed wiring board on which a polygon mirror drive circuit for rotating the polygon mirror 14 at a constant speed is constructed.

16 is an fθ lens assembly, which consists of two lenses 17 and 1.
8 is assembled into a holder 19, and the holder 19 is fixed to the substrate 1.

Lenses 17, 18 and holder 19 are polygon mirror 1
4, it has a horizontally elongated shape in the scanning direction of the beam. First, the holder 19 has a U-shaped upper surface, and as shown in FIG. 4, a horizontally elongated hole 19a is formed in the central portion, and stepped portions 19C to 19e are sequentially formed on both sides of the inner surface 19b where the hole 19a is formed. has been done.

The lens 19 is fixed by fitting its ends into both corners of the inner surface 19b and pressing it with the spring plate 20.

This spring plate 20 has a shape that presses the outer periphery of the effective portion of the exit surface of the beam passing surface of the lens 19. That is,
This spring plate 20 consists of a window portion 20a that exposes the effective portion of the passing surface of the lens 19, a frame portion 20b surrounding the window portion 20a, and mounting portions 20C at both longitudinal ends of the frame portion 20a. The lens 18 is held by tightening the portion 20c to the stepped portion 19C of the holder 19 with a screw, with or without a spacer.

Further, another lens 17 is held in a state where it is fitted into the stepped portion 19d of the holder 19 by tightening a spring plate 50 having the same color and shape as the spring plate 20 to the stepped portion 19e with a screw.

21 is a cylindrical lens as an optical lens, which is used for correcting the inclination angle of the polygon mirror 14. This cylindrical lens has non-lens parts 21 on both sides.
a and 21b are held perpendicularly to the substrate 1 by being held between pins 22.23 implanted in the substrate 1 and a pressing plate 24.25.

21C is a lens section. Further, a cushioning material 26.2 is provided between the pressing plate 24.25 and the non-lens parts 21a and 21b.
7 is interposed (a part is shown in FIG. 5).

Reference numeral 29 denotes an inclined mirror for changing the optical path downward by 90 degrees, and as shown in FIG.
1 to the substrate 1. Note that one holder 31 holds another vertical mirror 32.
3 is fixed.

34 is a timing detection photodetector that receives and detects the beam reflected by this mirror 32, and is located in front of one non-lens portion 21b of the cylindrical lens 21, and is attached to a holder 35 for detecting a horizontal synchronizing signal. It is fixed to a printed wiring board 36 that constitutes a detection circuit. This holder 35 is fixed to the substrate 1.

37 is a photosensitive drum 38 provided on the circumferential surface of the drum base.
This is a process section that contains other components, and this process section 3
7 and the mirror 29 is a substrate l and a dustproof glass 39.
It is divided into

The dust-proof glass 39 is mounted on the substrate 1 so as to straddle the steps 40a and 40b on the upper surface side of the long hole 40 formed along the longitudinal direction of the mirror 29. , 40b have different depths, and as a result, the dustproof glass 39 is not parallel to the surface of the substrate 1, that is, the surface is not perpendicular to the beam from the mirror 29.

Cushioning materials 41 to 43 are interposed to attach the dustproof glass 39 to the step portions 40a and 40b, and the above-mentioned holder 30 for the mirror 29 is placed on top of the dustproof glass 39 placed in this manner. 31 and is fixed.

The fθ lens assembly 16 and the cylindrical lens 21 described above are arranged at a position where the laser incident surface of the photosensitive drum 38 is optically conjugate with the beam reflecting surface of the polygon mirror 14.

Further, the above-mentioned photodetector 34 is optically connected to the photoreceptor drum 3.
It is placed at a position equivalent to the incident plane of the beam No. 8.

Now, the semiconductor laser 2 emits a laser beam modulated in accordance with the recording signal, which is made into parallel light by a collimating lens built in the front surface, and then vertically focused by a cylindrical lens 5, which is then focused onto a mirror 10. The beam enters the polygon mirror 14 as a horizontal beam.

By the way, depending on the product of the semiconductor laser 2, the spread of the emitted beam in the direction parallel to the pn junction surface may range from 8° to 15°.
The spread in the direction perpendicular to the joint surface is also 206°.
It is about ~40°, and there is considerable variation.

As a result, from this semiconductor laser 2 to the polygon mirror 14
If the state of the optical path up to the polygon mirror 14 is fixed, the convergence state of the beam incident on the polygon mirror 14 will vary, and the quality of the recording result obtained will be unfavorable.

Therefore, in this embodiment, the position of the cylindrical lens 5 is made adjustable in the direction of the arrow a, that is, in the direction along the optical axis of the beam, as described above, so that the beam can enter the polygon mirror 14 in a predetermined focused state. This absorbs variations in the beam spread of the semiconductor laser 2 between products.

The beam reflected by the polygon mirror 14 passes through the rθ lens assembly 16, further passes through the cylindrical lens 21, is reflected downward by the mirror 29, passes through the dustproof glass 39, and is exposed to the photosensitive drum 38. incident on the surface. Even if a part of the beam is reflected upon entering the dust-proof glass 39, the reflected component will not return to the incident side because the dust-proof glass 39 is not perpendicular to the incident optical axis.

The beam incident on the photosensitive drum 38 is deflected by the polygon mirror 14 and moves in the main scanning direction (in the direction of the arrow in FIG. 1), so the beam moves on the photosensitive drum 38 in the axial direction of the drum base. Also, since this photoreceptor drum 38 rotates in the direction of arrow C, main scanning in the direction of arrow A and sub-scanning in the direction of arrow C are performed on the photoreceptor drum 38, and characters and images are recorded on a surface. It is done. Incidentally, this photosensitive drum 38 is developed in a process subsequent to the incident of the beam, and transferred to a recording paper in a subsequent process.

Main scanning of the polygon mirror 14 is performed only in the direction indicated by the arrow, but at the start of the scanning, the cylindrical lens 21
The beam that has passed through the lens portion 21C deviates from the end of the mirror 29 and enters the mirror 32, is reflected there, passes through one non-lens portion 21b of the cylindrical lens 21 in the opposite direction, and enters the photodetector 34. By doing so,
The timing for starting scanning is determined. That is, the timing signal detected by the photodetector 34 becomes a horizontal synchronizing signal, and the modulation of the semiconductor laser 2 is started in synchronization with this signal.

〔Effect of the invention〕

In view of the above, according to the present invention, lenses and mirrors are press-fixed to the support member using a frame-shaped spring plate, so there is no need for screws or the like to fix them at all, making assembly easy and improving work efficiency. In addition, the number of parts is reduced, which is advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a recording device according to an embodiment of the present invention, FIG. 2 is a perspective view of a semiconductor laser and cylindrical lens assembly, FIG. 3 is an exploded perspective view of a mirror assembly, and FIG. 4 is an fθ
FIG. 5 is an exploded perspective view of the lens assembly, and is an explanatory diagram of a portion that changes the beam optical path downward. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Semiconductor laser, 3... Holder, 4... Cylindrical lens assembly, 5... Cylindrical lens, 6... Holder, 7... Rail,
8... Spring plate, 9... Mirror assembly, 10... Mirror, 11... Holder, 12... Spring plate, 13...
・Printed wiring board, 14...Polygon mirror, 15・
...Printed wiring board, 16...fθ lens assembly, 1
7.18... Lenses constituting the rθ lens, 19...
・Holder, 20.50...Spring plate, 21...Cylindrical lens, 22.23...Bin, 24.25・
...Press plate, 26.27...Cushion material, 29...
-Mirror, 30.31...Holder, 32...Mirror, 33...Holder, 34...Photodetector, 35...
Holder, 36... Printed wiring board, 37... Process section, 38... Photosensitive drum, 39... Dust-proof glass, 40... Elongated hole, 41-43... Cushioning material.

Claims (2)

[Claims] (1) A beam modulated according to a recording signal is incident on a deflecting means via a lens and/or a mirror to perform main scanning, and the photosensitive means moves in a sub-scanning direction intersecting the main scanning direction. A recording device for recording characters or images corresponding to the recording signal on the photosensitive means by inputting the recording signal, characterized in that the lens and/or mirror is pressed and fixed to a support member by a frame-shaped spring plate. . (2), the spring plate has a frame shape with an almost U-shaped upper surface;
A window through which the beam passes is formed in the central piece of the U-shaped portion, and pressing pieces bent inward are formed at the ends of the side pieces on both sides of the central piece opposite to the central piece. 2. The recording device according to claim 1, wherein said support member is pressed by a piece.