JP2002328320A - Deflection scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost by eliminating a BD holder for holding a BD mirror of a deflection scanner used for an LBP, copying machine or the like. SOLUTION: The part holding the BD mirror is constituted at an extended part of an optical box.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection scanning device used for a laser beam printer or a laser facsimile.

[0002]

2. Description of the Related Art Conventionally, this type of apparatus has been configured as shown in FIG.

In FIG. 5, reference numeral 21 denotes an optical box of a main body of the apparatus.
It is formed of a resin material containing a fibrous glass material.

Reference numeral 22 denotes a laser output device for emitting a laser beam, 23 denotes a cylindrical lens, 24 denotes a polygon mirror, 25 denotes a drive motor, 26 and 27 denote scanning lenses, 18 denotes a photosensitive drum, and 29 denotes a BD mirror. , 30 is a BD slit, 31 is a BD lens, 32 is a BD sensor, 33 is a BD sensor holder, 34 is a return mirror, and 35 is a BD mirror holder.

The laser light emitted from the laser output device 22 is condensed on a polygon mirror 24 by a cylindrical lens 23 and is deflected by a driving motor 25 which rotates at high speed. , 27 to form an image on the surface of the photosensitive drum 28.

A part of the laser light deflected by the polygon mirror 24 is reflected by a BD mirror 29, passes through a BD slit 30, is imaged on a BD sensor 32 by a BD lens 31, and is converted from an optical signal into an electric signal. And outputs a laser write start signal.

[0007] Here, BD mirror 19 is held by the BD mirror holder 25 is attached while adjusting the angle of the attachment shown theta _f of the BD mirror holder 25.

The writing position of the change scanning device is determined by the angle θ _f .

[0009]

However, in the above conventional example, the writing angle is adjusted by adjusting the mounting angle of the BD mirror holder.
Although it is an essential component, it can be adjusted by other methods, and the BD mirror holder is not always a necessary component. Therefore, there is a disadvantage that the cost is high.

In the case where a mold spring is simply formed at an extended portion from the optical box, the mold spring is difficult to strengthen in terms of its function. Therefore, when handling the optical box, the mold spring may be bumped against other parts. And there is a problem with reliability.

An object of the present invention is to solve the above-mentioned problems and to provide a deflection scanning device capable of reducing the cost by eliminating the BD mirror holder.

[0012]

In order to achieve the above-mentioned object, the deflection scanning apparatus according to the present invention solves the problem by making the BD writing start adjustment an electrical adjustment or by shaking the optical box right and left. In order to mount the BD mirror with high accuracy, the reflection surface of the BD mirror is accurately abutted and held by an extension from the optical box, and the back surface of the BD mirror is pressed by a mold spring. At this time, in view of the function of pressurizing the mold spring, there is a limit in increasing the mechanical strength, and thus it is necessary to arrange a protection pin or the like near the mold spring.

As described above, the BD mirror holder is abolished, and the cost can be reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention. 1 is a plan view, and FIG. 2 is a sectional view.

Since the overall configuration is the same as that of the conventional example, a detailed description is omitted.

1 and 2, reference numeral 1 denotes a BD mirror holding portion, 2 denotes a molded spring protection pin, 3 denotes a molded spring, 4 denotes a BD mirror, 5 denotes an optical box, 6 denotes a skirt portion, and 7 denotes an R-shaped portion.

At this time, the BD mirror holder has been abolished, and the reflecting surface of the BD mirror 4 is
Then, the back surface of the BD mirror is pressed and held by the mold spring 3 with high accuracy.

In view of the function of the mold spring 3, there is a limit to increasing the mechanical strength. To prevent damage to the mold spring when handling parts, the mold spring protection pin 2 is placed near the mold spring. Protect by standing.

Further, it is possible to avoid stress concentration by forming the rounding 7 at the root of the mold spring.

When the mold spring portion 3 is formed as an extension from the optical box 5, a hole is formed in the optical box 5 due to the configuration of the mold, so that a skirt-like extension is provided to prevent intrusion of dust. Is provided below the optical box 5.

Although not particularly shown, the writing start adjustment does not necessarily need to be adjusted by the tilt of the BD mirror holder, but may be adjusted electrically or by shaking the optical box right and left. The holder is not an indispensable part but a disposable part.

Therefore, the BD mirror holder is abolished,
Cost reduction is possible.

(Second Embodiment) FIGS. 3 and 4 show a second embodiment of the present invention.

FIG. 3 is a plan view, and FIG. 4 is a sectional view. 3 and 4, reference numeral 8 denotes a stress limit stopper.

When inserting the BD mirror 4 with the mold spring 3 bent slightly, the stress limit is easily exceeded unless the amount of deflection is regulated. Therefore, the stress limit does not reach the back of the mold spring. Providing the stopper at the position facilitates the assembling work.

[0026]

As described above, according to the present invention,
The reflecting surface of the BD mirror is accurately abutted and held by the extended portion of the optical box, and the back surface of the BD mirror is pressed and held by a mold spring formed by the extended portion of the optical box.

The BD writing adjustment can be performed by a method such as electrical adjustment or adjustment by shaking the optical box right and left.
Since the BD mirror holder can be eliminated, there is an effect that the accuracy of the mirror mounting surface is increased, the number of parts is reduced, the cost is reduced, and the assembly is simplified.

However, in terms of its function, the mold spring has a limit in increasing its mechanical strength. To protect the mold spring, it is necessary to provide a protection pin or a stress limit stopper near the mold spring.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is a cross-sectional view of the first embodiment.

FIG. 3 is a plan view of a second embodiment.

FIG. 4 is a sectional view of a second embodiment.

FIG. 5 Conventional example

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 BD mirror holding part 2 Mold spring protection pin 3 Mold spring 4 BD mirror 5 Optical box 6 Skirt part 7 R removal 8 Stress limit stopper 21 Optical box 22 Laser output device 23 Cylindrical lens 24 Polygon mirror 25 Drive motor 26, 27 Scan lens 28 Photosensitive Drum 29 BD Mirror 30 BD Slit 31 BD Lens 32 BD Sensor 33 BD Sensor Holder 34 Back Mirror 35 BD Mirror Holder

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C362 AA42 AA45 BA83 BA87 BA90 BB30 DA03 DA14 2H043 CA04 CA07 CE00 2H045 AA01 CA89 DA02 5C072 AA03 BA20 HA02 HA08 HA13 HA15 XA05

Claims (4)

[Claims] 1. A deflection scan for deflecting a laser beam emitted from a laser unit using a semiconductor laser chip as a light emitting source by a polygon mirror provided in a motor drive unit, forming an image by a scanning lens, and scanning a photosensitive member. In order to obtain a horizontal synchronization signal with the device, a part of the laser light is reflected by a BD mirror,
After passing through the BD slit, an image is formed on the BD sensor by the BD lens, and the deflection scanning device has a resin optical box for accommodating the BD sensor, the reflecting surface side of the BD mirror is abutted by an extension from the optical box. A deflection scanning device characterized in that the rear surface is held by pressing and fixed by a resin-made elastic spring formed of a portion extending from the optical box. 2. The deflection scanning according to claim 1, wherein a protection pin or a protection wall is provided near the mold spring to protect the mold spring formed integrally with the optical box made of resin. apparatus. 3. When inserting the BD mirror, a mold spring formed integrally with the optical box made of resin is inserted while being bent. At this time, a stopper for preventing the spring from being largely bent is provided. 3. The deflection scanning device according to claim 1, wherein an extension of the optical box is provided on a back surface of the spring. 4. When the mold spring is formed by an extension from the optical box, a hole is formed in the vicinity of the spring due to a mold configuration. 4. The deflection scanning device according to claim 1, wherein an extension portion is provided below the optical box.