JPS61144621A - Dustproof plate for optical unit - Google Patents

Abstract

PURPOSE:To obtain a dustproof plate of an optical unit which is rigid and durable with ease of manufacture by molding integrally a light transmitting part, a sliding piece to be engaged with the guide part of the optical unit in sliding contact therewith in the stage of attaching and detaching and a gripping part to be gripped in the stage of attaching and detaching by using a light transmittable synthetic resin. CONSTITUTION:Laser light from a semiconductor laser 4 arrives at a rotary polygon mirror 6 via a collimator lens 5 and is changed continuously in the exit direction by said mirror, by which the laser light is oscillated in the scanning direction. The laser light irradiates a photosensitive body 14 via the dustproof plate 9 after the laser light is successively reflected by an ftheta lens L1, the 1st mirror 7 and the 2nd mirror 8. The semiconductor laser 4, the collimator lens 5, the rotary polygon mirror 6, the ftheta lens L1, the 1st mirror 7, the 2nd mirror 8, etc. are installed in a frame 15 which is the outside plate of the optical unit and the light is conducted through the dustproof plate 9 mounted in the aperture of the frame 15 to the body 14. The dustproof plate 9 has an I-shaped section and the light transmitting part 100, the sliding piece 200 and the gripping part 300 are integrally molded of the same material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a dustproof plate for an optical unit, and more particularly to a dustproof plate for an optical unit that can be used in an optical unit of an electrophotographic copying machine or a laser printer.

(Prior Art) Conventionally, in an optical unit Ic of a laser printer or an electrophotographic copying machine, a dustproof plate is detachably attached to a light exit window thereof.

Figure 4 shows a dustproof plate used in the optical unit of a laser printer, and reference numeral 1 denotes a light transmitting part made of, for example, blue plate glass. Reference numeral 2 denotes an eave-shaped sliding piece, which is a member that engages and slides into contact with the guide portion of the optical unit when it is attached to or removed from the optical unit.

Further, reference numeral 6 indicates a handle portion, which is a portion that is held by the operator when attaching and detaching the optical unit.

In this dustproof plate, a light transmitting part 1 is directly adhered to a sliding piece 2 and a handle part 6, which are integrally molded of opaque synthetic resin, as shown in Figure 5, or is integrally formed by means such as double-sided tape. It is installed and configured.

For example, Figure 10 shows a dustproof plate used in an optical unit of an electrophotographic copying machine.

In the figure, the reference numeral 10 indicates a light transmitting portion, the reference numeral 20 &@ indicates a sliding piece that engages and slides with the guide portion of the optical unit, and the reference numeral 60 indicates a handle portion that is gripped by an operator during attachment and detachment. In this dustproof plate, a light transmitting part 10 is directly adhered to a sliding piece 20 and a handle part 30, which are integrally molded of opaque synthetic resin, as shown in FIG. Alternatively, they are attached integrally by means such as double-sided tape.

In this way, conventional dustproof plates are constructed by combining multiple parts, which requires a lot of man-hours to assemble.In addition, since the light-transmitting part is attached via adhesive means, for example, the use of cleaning agents during cleaning There is no adhesive, and there is one for cleaning! ! ! There were problems such as the solvent seeping into the double-sided tape part and the adhesive part peeling off, creating a gap and impairing the sealing performance.

Furthermore, since the light transmitting portion is made of elongated glass, accidents such as damage due to torsional force applied during attachment and detachment due to careless handling are likely to occur.

(Objective) Accordingly, an object of the present invention is to provide a dustproof plate for an optical unit that is easy to manufacture, robust, and durable.

(Structure) In order to achieve the above object, the present invention includes a light transmitting part, a sliding piece that engages and slides into contact with the guide part of the optical unit when attaching and detaching, and a gripping part that is gripped when attaching and detaching the light transmitting part. It is characterized by being integrally formed of synthetic resin.

The present invention will be specifically explained below based on one actual case.

Figure 1 shows an example of the optical system of a laser printer. To explain the outline, a laser source from a semiconductor laser 4 that emits light in response to a write signal passes through a collimator lens 5 and reaches a rotating polygon mirror 6, where the emission direction is continuously changed and deflected in the scanning direction. You will be able to do it. And fθ lens L1 1. ? After being sequentially reflected by the first mirror 7 and the second mirror 8, the dustproof plate 9 according to the present invention
The photoreceptor 14 is then irradiated.

Here, semiconductor laser 4. Collimator lens 5° rotating polygon mirror 6. fθ lens r=1, . 4y1 Mirror 7°, 2nd mirror 8, etc. are located outside the optical unit as shown in Figure 2.
It is installed in a barrel frame 15, and the frame 1
The light is guided to the photoreceptor 14 via the dustproof plate 9 attached to the opening of the photoreceptor 5.

The photoreceptor 14 has an endless belt shape, and around it are a charging tank 16, a developing unit 17, a transfer charger 18, and so on. A cleaner 19 etc. are arranged.

As shown in FIGS. 1 to 16, the dustproof plate 9 has an I-shaped cross section, and the light transmitting part 100, the sliding piece 200, and the handle part 300 are made of the same material and are integrally formed.

Here, as shown in FIG. 16, if the light transmitting part 100' is formed on the same surface as the sliding piece 200' and the whole is formed into a long flat plate shape, twisting and warping will be prevented when attaching and detaching from the frame 15. Therefore, in order to prevent this, the thickness must be increased, and if this is done, the light transmission efficiency will deteriorate. Therefore, the light transmitting portion 100 is formed to be more concave than the portion of the sliding piece 200, that is, the cross-sectional shape is formed into a rough shape. This increases the section modulus and increases the strength, making it possible to reduce the thickness and improve light transmission efficiency.

The material is methacrylic resin with high light transmittance.

Use AS resin or the like. In particular, PMMA resin is suitable for use because it has excellent optical properties.

Note that the sliding piece 200 is attached to the guide portion 35 (spear 2) of the optical unit.
It has the function of being engaged with the connector (see figure) and being guided and slid during attachment and detachment.

Next, Figure 7 shows an example of an optical system of an electrophotographic copying machine.

In the figure, the optical unit is composed of a housing recessed with a contact glass 21 and a frame 22.

As is well known, a light source 23, a reflecting mirror 24, a spear 1 mirror ml, a spear 2 mirror m2, a spear 3 mirror m3, a spear 4 mirror m4, a steel lens system e, etc. are arranged in this housing. It is set up. The lens system e is an example of lens 11. e2. 65. It consists of 64 etc.

The reflected light from the original on the contact glass 21 is finally reflected by the mirror 4 m4 and reaches the photoreceptor 140 via the dustproof plate 90.

This dustproof plate 90 also has a light transmitting part 1000 and a sliding piece 200.
0 and the handle portion (corresponding to the one indicated by the reference numeral 60 in FIGS. 1-10) are made of the same material by integral molding.

The material used is a transparent synthetic resin similar to the above example.

It should be noted that if the central part of the dust-proof plate 9000 transmission part is formed into a lens shape as shown by the reference numeral 1ooo' in Figures 8 and 9, the lens 14 in Figure 7 can be replaced. In the figure, reference numeral 2000' indicates a sliding piece, and reference numeral 6000 indicates a handle.

(Effects) Since the dustproof plate according to the present invention has the gripping part, light transmitting part, sliding part, etc. integrally molded, it is easy to manufacture and costs are reduced, and it is also robust and has improved reliability. It is convenient in this respect.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the main parts of the optical system of a laser printer, Figure 2 is a perspective view of the main parts of the optical system of a laser printer.
The figures are the same as the above figure and a front view of the surrounding area, Figure 3 is a sectional view of the dustproof plate according to the present invention, Figure 4 is a perspective view of a conventional dustproof plate,
Figure 5 is a sectional view 1--A of the same figure. Figure t-6 is a partial perspective view of the dustproof plate according to the present invention. The off-line diagram is a sectional view of the optical unit of an electrophotographic copying machine, Figure 8 is a sectional view of the dustproof plate according to the present invention, Figure 9 is a perspective view of the same figure as above, and Figure 10 is a sectional view of the dustproof plate according to the prior art. The perspective view, Figure 11, is probably a cross-sectional view taken along line B-B in the same figure. 9, 90. 900...Dustproof plate. Figure 1 Figure %7

Claims (1)

[Scope of Claims] A light-transmitting dust-proof plate detachably attached to a light exit window of an optical unit, comprising a light-transmitting part and a sliding piece that engages and slides into contact with a guide part of the optical unit when attached or detached. Furthermore, a dustproof plate for an optical unit is characterized in that a handle portion that is gripped during attachment and detachment is integrally molded from a light-transmitting synthetic resin.