JPH1058750A - Optical writing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to close tightly an optical path, and to prevent oblivion to mount a dust-proof glass when the dust-proof glass blocking the optical path between an optical unit and an image-producing unit is removed for cleaning. SOLUTION: An optical writing device wherein an optical unit 1 and an image-producing unit 2 are connected by an optical path 9 which transmits an image forming luminous flux and the optical path 9 is blocked by a dust- proof glass 10 in which the dust-proof glass 10 is provided freely retretably from the position of blocking the optical path 9, and when the dust-proof glass 10 retreats from the optical path 9, a shutter blocks the optical path 9 as being pushed by a spring means. When the dust-proof glass is removed for cleaning purposes, the shutter can block the optical path automatically, and if it is forgot to place the dust-proof glass, miscopy occurs and thereby the oblivion is noticed surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analog or digital optical writing device, and more particularly to a dustproof mechanism in an optical unit.

[0002]

2. Description of the Related Art Many optical writing apparatuses such as printers, copiers, and facsimile machines use an electrophotographic system. In a general configuration of the electrophotographic system, light from an optical unit is exposed on a uniformly charged photosensitive drum to form an electrostatic latent image, and toner is adhered to the electrostatic latent image to form a toner image. This toner image is transferred onto a transfer sheet and fixed to fix the image.

In such an optical writing device, the optical unit has a hermetically sealed structure in order to prevent contamination of optical elements such as lenses and mirrors due to dust and dirt in the air and scattered toner inside the device. It is formed separately from an imaging unit having a body or the like. However, the image forming light beam (laser light) from the optical unit must be introduced into the image forming unit, and therefore, the optical unit and the image forming unit are connected by an optical path. This optical path is sealed with transparent dustproof glass so that dust and the like from the image forming unit do not enter the optical unit.

However, the surface of the dust-proof glass is gradually contaminated by scattered toner and the like in the image forming unit. Therefore, the dust-proof glass needs to be periodically removed and cleaned. However, in the conventional optical writing device, if the dust-proof glass is taken out, cleaned, and the user forgets to attach it again, dust enters the optical unit and contaminates the above-described optical elements. Further, if the image forming operation is performed as it is, the scattered toner of the image forming unit invades the optical writing unit and seriously stains the optical element.

[0005]

SUMMARY OF THE INVENTION The present invention has been conceived in view of the above facts, and provides an optical writing device capable of closing the optical path when the dust-proof glass of the optical unit is removed and preventing forgetting to attach the dust-proof glass. It is intended to be.

[0006]

According to the present invention, an optical unit and an imaging unit are connected by an optical path through which an image forming light beam passes, and the optical path is closed by a transparent dustproof glass. The optical writing device is characterized in that the dust-proof glass is provided so as to be able to retreat from a position for blocking the optical path, and a shutter is provided for blocking the optical path when the dust-proof glass is retracted from the optical path.

The shutter is substantially in the same plane as the dust-proof glass, and is pressed against the dust-proof glass by a spring means. When the dust-proof glass moves in the plane and retracts from the optical path, the shutter moves by the spring means. It is desirable that the optical path be closed.

Further, an optical sensor is provided outside the image range of the image forming unit, and when the optical sensor does not detect light, the optical writing device is not operated. A side mirror is provided, and a synchronization detection sensor is disposed at a position where the reflected light from the light source side mirror is incident. The shutter has a shutter side mirror that reflects a light beam outside the image range and emits light to the synchronization detection sensor. Provided,
The optical writing device may not be operated when the synchronization detection sensor detects the reflected light from the shutter side mirror.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of an optical writing apparatus according to the present invention, and FIGS. 2 and 3 are views showing details of a portion A in FIG.

In FIG. 1, reference numeral 1 denotes an optical unit and 2 denotes an image forming unit. The optical unit 1 has a hermetically sealed structure, in which a polygon mirror 3, an fθ lens 4, a mirror 5, an imaging lens 6, and a mirror 7 are provided. In the image forming unit 2, only the photosensitive drum 8 is illustrated, and other components are omitted. In addition to the above, components necessary for the electronic image forming apparatus such as a charging device, a developing device, and a fixing device are arranged around the photosensitive drum 8. Are located.

The optical unit 1 is connected to the image forming unit 2 by an optical path 9, but if nothing is placed between them,
Dirt and dust generated in the image forming unit 2 enter. Thus, the optical path 9 is covered with dustproof glass 10 to prevent dust and toner from the image forming unit 2 from entering the optical unit 1. Further, a gap between the dust-proof glass 10 and the optical unit 1 is airtightly closed by a sponge 11.

FIG. 2 is an enlarged view of the periphery of the dust-proof glass 10. The dustproof glass 10 is movable in the direction of the arrow in the plane of the glass. On the right side of the dust-proof glass 10, there is a shutter 12 in the same plane as the dust-proof glass, and this shutter 12 is urged to the left in the drawing by a spring means 13 and abuts against the end face of the dust-proof glass 10.

When the dustproof glass 2 is pulled out in the direction of the arrow and removed, the shutter 12 is pushed by the spring means 13 and the shutter 12 is turned off.
And the optical path 9 is closed. The sponge 11 is in close contact with the shutter 12 to prevent dust and dirt from entering the optical unit 1.

With only the above configuration, the dustproof glass 10
Is removed for cleaning, the shutter 12 is automatically closed and the optical path 9 from the optical unit 1 to the image forming unit 2 is blocked, so that dust and dirt can be prevented from entering. And dustproof glass 1
After cleaning 0, forgetting to insert it and perform the image forming operation as it is, it will be a blank copy without being exposed to the photoconductor,
It is possible to notice that the user has forgotten to put on the dust-proof glass, and to surely prevent forgetting to put on.

FIG. 4 However, a blank copy is a miscopy and is useless. Therefore, in the embodiment of FIG. 4, the optical sensor 14 is mounted in the image forming unit 2. This optical sensor 14 is provided at a position outside the range scanned by the light beam,
Make sure that the laser light is not blocked during image formation.

Before performing an image forming operation, a light source (not shown) is turned on, and a light beam from the light source is scanned on a photosensitive drum 8 through a polygon mirror 3, an fθ lens 4, a mirror 5, an imaging lens 6, and a mirror 7. Irradiate while. Then, it is determined whether or not the dust-proof glass 10 has been fitted, based on whether or not this light flux has entered the optical sensor 14.

That is, when the dust-proof glass 10 is in, the light of the light source passes through the dust-proof glass 10 and the optical sensor 14 is turned on.
N. Shutter 1 when dustproof glass 4 is not inserted
2 interrupts the optical path, so the optical sensor 14 is OFF
Becomes The optical writing device that has detected that the dust-proof glass 10 is not inserted does not perform the image forming operation, and can notify the user or the like by displaying that the dust-proof glass 10 is not inserted on the liquid crystal screen of the operation panel or the like. .

FIG. 5 is a diagram showing another embodiment of the present invention. In order to prevent erroneous copying, in the embodiment of FIG. 4, one optical sensor 14 must be added, which increases the cost. In addition, since the optical sensor 14 is located in the image forming unit 2 near the photoconductor, the optical sensor 14 is liable to be contaminated with scattered toner or the like in the unit, and is likely to be defective.

Therefore, in the embodiment shown in FIG.
The optical writing unit 1 has a light source side mirror 16 and a synchronization detection sensor 17. These are all arranged so as to be outside the image range of the laser light when the laser light is scanned in the main scanning direction.

The laser beam reflected by the mirror 7 passes through the dust-proof glass 10 (see FIG. 1) and reaches the photosensitive member 8;
A part thereof is reflected by the light source side mirror 16 and turned back to be incident on the synchronization detection sensor 17. Synchronous detection sensor 17
The image writing position in the main scanning direction is controlled by the timing detected by the.

In the normal state where the dust-proof glass 4 is contained, the light reflected by the light source side mirror 16 is incident on the synchronous detection sensor 17 only once for the main scanning 1 scanner.
However, when the dust-proof glass 10 is not inserted, the shutter 12 is closed as shown in FIG. 5, and the light incident on the shutter-side mirror 15 on the shutter 12 is turned back and is incident on the synchronization detection sensor 17. That is, light enters the synchronization detection sensor 17 twice with respect to one main scanning scanner. Therefore, the optical writing device emits a laser beam before performing the image forming operation, detects the presence / absence of the dust-proof glass 10 using the difference in the light incident on the synchronization detection sensor 17, and stops the image forming operation. Actions such as notification to the user can be taken.

[0022]

As described above, according to the present invention, the optical unit and the imaging unit are connected by the optical path through which the image forming light beam passes, and the optical path is closed by the transparent dustproof glass. In the apparatus, since the dust-proof glass is provided so as to be retractable from a position that closes the optical path, and a shutter that closes the optical path when the dust-proof glass is retracted from the optical path is provided, so that the dust-proof glass can be removed for cleaning. The optical unit can be closed by the shutter, and dust and toner can be prevented from entering the optical unit from the optical path. Also, if the user forgets to put on the dust-proof glass, a miscopy will occur.

The shutter is substantially in the same plane as the dust-proof glass, and is pressed against the dust-proof glass by a spring means;
If the shutter moves by spring means to close the optical path when the dust-proof glass moves in the plane and retreats from the optical path, the optical path can be automatically closed by the shutter when the dust-proof glass is removed.

An optical sensor is provided outside the image area of the image forming unit, and if the optical sensor does not detect light, the optical writing device is not operated. Miscopying can be prevented.

A mirror is provided outside the image range in the optical unit, a synchronization detection sensor is provided at a position where the reflected light from the mirror is incident, and the shutter detects the light flux outside the image range by reflecting the light beam outside the image range. If a mirror that emits light is provided, even if the dust-proof glass is forgotten to be attached, it is possible to prevent erroneous copying and to prevent contamination of the synchronization detection sensor and the mirror.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an optical writing device of the present invention.

FIG. 2 is a detailed view of a portion A in FIG. 1, (a) is a front view,
(B) is a bottom view.

FIG. 3 is a view showing a state in which a shutter is closed in FIG. 2;
(A) is a front view, (b) is a bottom view.

FIG. 4 is a diagram showing a configuration of another embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of still another embodiment of the present invention.

6A and 6B are diagrams showing details of the embodiment in FIG. 5, wherein FIG. 6A is a front view and FIG. 6B is a bottom view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical unit 2 Imaging unit 9 Optical path 10 Dustproof glass 12 Shutter 13 Spring means 14 Optical sensor 15 Shutter side mirror 16 Light source side mirror 17 Synchronous detection sensor

Claims (4)

[Claims] 1. An optical writing device wherein an optical unit and an image forming unit are connected by an optical path through which an image forming light beam passes, and the optical path is closed by a transparent dust-proof glass. An optical writing device provided with a shutter which is provided so as to be retractable and which closes the optical path when the dust-proof glass is retracted from the optical path. 2. The shutter is substantially in the same plane as the dust-proof glass, and is pressed against the dust-proof glass by a spring means. When the dust-proof glass moves in the plane and retracts from the optical path, the shutter moves by the spring means. 2. The optical writing device according to claim 1, wherein the optical path is closed by a step. 3. The optical writing device according to claim 1, wherein an optical sensor is provided outside an image range of the image forming unit, and the optical writing device is not operated when the optical sensor does not detect light. Optical writing device 4. A light source side mirror is provided outside the image range in the optical unit, a synchronization detection sensor is arranged at a position where the reflected light from the light source side mirror is incident, and the shutter reflects a light beam outside the image range. 3. The synchronous detection sensor according to claim 1, further comprising a shutter-side mirror that emits light, wherein the optical writing device is not operated when the synchronous detection sensor detects reflected light from the shutter-side mirror. Optical writing device.