JPH088108Y2 - Optical scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an optical scanning device applied to an electrophotographic apparatus such as a laser printer.

[Prior Art] FIG. 3 shows a schematic configuration of a conventional electrophotographic apparatus.

In the figure, reference numeral 1 is a frame in which each component of the electrophotographic apparatus is incorporated. The frame 1 is divided into an upper frame 1U and a lower frame IL so that the photosensitive drum can be easily replaced, maintained and inspected. The upper frame 1U is configured to be openable and closable around one point.

Here, the photosensitive drum 2 and the like are mounted on the lower frame 1L, and the optical scanning device 11 is mounted on the upper frame IU. As shown in FIGS. 3 and 4, a laser light source 14, a rotary polygon mirror (so-called polygon mirror) 15, an imaging lens 16, reflection mirrors 17, 18 and the like are provided in the cover 12 of the optical scanning device 11. ing.

Then, the laser light corresponding to the print data emitted from the laser light source 14 is directed from the laser emission port 13 of the cover 12 to the photosensitive drum 2 through the rotary polygon mirror 15, the imaging lens 16, the reflection mirrors 17 and 18, and the like. Are irradiated (laser optical path L1).
Then, the electrostatic latent image formed on the photosensitive drum 2 by the laser beam is developed and transferred and fixed on the sheet.

By the way, it is dangerous for the laser beam to directly hit the human body when the upper frame 1U is opened for inspection or the like. Therefore, the electrophotographic apparatus is provided with various safety means.

That is, in general, an electrophotographic device has an upper frame 1U.
There is provided an opening detection device (not shown) that detects the opening of the laser light source by a micro switch or the like and stops the driving of the laser light source 14.

Further, the electrophotographic apparatus may be provided with a shutter 5 for shutting off the laser optical path L1 as shown in FIG. 4 so as to be safe even if the opening detection apparatus does not operate.
The shutter 5 is rotatably supported by a mount 19 in the cover 12, and when the upper frame 1U (and hence the cover 12) is opened, it rotates in the direction of arrow P with respect to the cover 12 by its own weight to shut off the laser optical path L1. When the upper frame 1U is closed, the cover 12 is rotated by its own weight in the direction of the arrow Q to release the interruption of the laser optical path L1.

As a result, when the upper frame 1U (cover 12) is opened, the shutter 5 blocks the laser optical path L1 even if the opening detection device does not operate, so that further safety is ensured.

[Problems to be Solved by the Invention] By the way, in the above-described electrophotographic apparatus, even if the upper frame 1U (cover 12) is opened, the shutter 5 causes rotational resistance due to friction with the mounting base 19 or the like. cover
The laser optical path L1 may not be blocked without smoothly rotating relative to 12. Therefore, it is conceivable to increase the weight of the shutter 5 so that the shutter 5 can overcome the above rotation resistance and can be relatively rotated smoothly. But,
This causes a problem that the shutter 5 and thus the optical scanning device 11 become large in size, and it becomes impossible to meet the current demand for downsizing of the electrophotographic device.

Further, when the upper frame 1U (cover 12) is closed from the open state, if the frame 1U or the like is externally vibrated, the shutter 5 is released before the opening detection device is activated.
May sway, the interruption of the laser optical path L1 may be released, and the laser light may leak to the outside, which is a safety problem.

In view of the above circumstances, an object of the present invention is to provide an optical scanning device capable of improving safety while achieving size reduction.

[Means for Solving the Problems] The present invention is an optical scanning system in which a light irradiation unit including a laser light source, a rotary polygon mirror, and a reflection mirror is housed in a cover that can be opened and closed and has a laser emission port. In the apparatus, the reflection mirror is attached to the cover so as to be rotatable according to the opening / closing posture of the cover, and an attitude regulating member for regulating the rotation of the reflection mirror is provided.

[Operation] In the present invention, when the cover is opened along with the opening of the upper frame of the electrophotographic apparatus, the reflection mirror rotates by its own weight with respect to the cover and is positioned at a predetermined position by the attitude regulating member. As a result, the laser optical path is changed, and even if the laser light is incident on the reflection mirror, the reflection light from the reflection mirror is prevented from being emitted to the outside from the laser emission port of the cover. Here, since the reflection mirror normally has a weight enough to overcome the frictional resistance or the like when it rotates, it is not necessary to increase the size.

Therefore, it is possible to improve safety while achieving miniaturization.

[Embodiment] An embodiment of the present invention will be described with reference to the drawings.

The optical scanning device according to the present embodiment is applied to an electrophotographic device, and as shown in FIG. 1, a cover 12, a laser light source 14,
The rotary polygon mirror 15, the imaging lens 16, the reflection mirrors 17 and 18, the rotation supporting means 21, the attitude regulating member 31, and the locking means 41 are included.

The same components as those shown in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof will be omitted or simplified.

Here, the rotation supporting means 21 is a means for attaching the reflection mirror (the reflection mirror 17 in this embodiment) to the cover 12 so as to be rotatable with the opening / closing posture of the cover 12. It is composed of a mirror holder 27 and the like which is rotatably held via a pin 26.

The attitude regulating member 31 is means for regulating the rotation of the reflection mirror 17 so that the reflected light from the reflection mirror 17 does not pass through the laser emission port 13 of the cover 12 when the cover 12 is opened. Further, in the present embodiment, the posture regulating member 31 is configured to regulate the rotation of the mirror 17 so that the reflection mirror 17 does not rotate too much when the cover is opened and cannot return when the cover 12 is closed. ing. Further, the posture regulating member 31
Is a reflection mirror in which laser light is emitted from the laser light source 14.
Even when the light is incident on the cover 17, the reflected light from the mirror 17 is covered by the cover 12.
The rotation of the reflection mirror 17 is regulated so that the reflection mirror 17 is incident on the antireflection member 39 attached to the inner wall surface.

Further, the locking means 41 is a reflection mirror when the cover 12 is closed.
A means for positioning and holding 17 at a predetermined printing position shown by a solid line in FIG. 1, and an engaging plate 42 provided on the reflecting mirror 17, and an inner wall surface of the cover 12 facing the engaging plate 42. The stopper 43 and the like are provided. Here, the engagement plate 42 is made of a magnetic material such as iron and serves as a stopper.
An electromagnet 44 is attached to the tip of 43. Therefore, when the cover is closed, the electromagnet 44 is excited to attract and hold the reflection mirror 17 through the engagement plate 42. Further, when the cover 12 is opened, the electromagnet 44 is demagnetized to release the attraction / holding relationship with the reflection mirror 17.

 Next, the operation will be described.

Top cover 1U for internal inspection of electrophotographic device
When the cover 12 is opened, the reflection mirror 17 rotates counterclockwise with respect to the cover 12 by its own weight and is positioned at a predetermined position by the posture regulating member 31, as shown in FIG. At this time, even if frictional resistance or the like acts on the reflection mirror 17, the reflection mirror 17 has a weight sufficient to overcome the resistance, so that the reflection mirror 17 smoothly rotates relative to the cover 12 and is rotated at a predetermined position by the attitude regulating member 31. Be positioned at.

As a result, the laser optical path is changed from L1 to L2, and even if the laser light is emitted from the laser light source 14, the laser light is incident on the antireflection member 39 by the reflection mirror 17. . Therefore, the reflected light from the reflection mirror 17 is not emitted from the laser emission port 13 of the cover 12 to the outside, and safety is ensured.

Further, when the upper cover 1U (cover 12) is closed in preparation for printing work, the reflection mirror 17 rotates clockwise with respect to the cover 12 by its own weight, and the locking means 41 performs predetermined printing shown by the solid line in FIG. Be positioned in position. This allows
The laser beam path returns to the laser beam path L1 for printing, and printing can be performed smoothly.

Thus, according to this embodiment, the reflection mirror 17 can be rotated according to the open / closed posture of the cover 12.
Attached to 12 and reflective mirror when cover 12 is open
Since the attitude regulating member 31 that regulates the rotation of the reflecting mirror 17 is provided so that the reflected light from 17 does not pass through the laser emission port 13, the laser light leaks from the case 12 to the outside when the cover is opened. No matter what, safety is ensured. Further, since the reflection mirror 17 has a weight sufficient to overcome the frictional resistance or the like even when it is rotated, the reflection mirror 17 does not need to be particularly large in size and can be easily downsized.

Further, even when laser light is emitted from the laser light source 14 when the cover is opened, the reflected light from the reflection mirror 17 is incident on the antireflection member 39 by the attitude regulating member 31, so that the reflected light is diffusely reflected inside the cover 12. As a result, there is no leakage to the outside through the laser emission port 19, and further safety can be secured.

Further, since the locking means 41 is provided, the reflection mirror 17 is positioned and held at a predetermined printing position when the cover is closed. Therefore, the laser light emitted from the laser light source 14 can be advanced along the laser light path L1 formed by the reflection mirrors 17, 18 and the like to be irradiated from the laser emission port 13 to a predetermined portion of the photosensitive drum 2, and smooth printing can be performed. Is guaranteed.

In the above embodiment, the laser light path is changed by rotating the reflection mirror 17, but the laser light path may be changed by rotating the reflection mirror 18.

[Advantages of the Invention] According to the present invention, the reflection mirror is attached to the cover so as to be rotatable in accordance with the opening / closing posture of the cover, and the posture regulating member for regulating the rotation of the reflection mirror is provided. Therefore, it is possible to improve safety while achieving miniaturization.

[Brief description of drawings]

1 and 2 are views showing an embodiment of the present invention, FIG. 1 is a cross-sectional view showing the entire structure, and FIG. 2 is a cross-sectional view showing a state in which a cover is opened. FIGS. 3 and 4 are views showing a conventional optical scanning device, FIG. 3 is a sectional view showing the entire structure, and FIG. 4 is a view showing a positional relationship between a laser light source and a shutter. 12 …… Cover, 13 …… Laser emission port, 14 …… Laser light source, 15 …… Rotating polygon mirror, 17 …… Reflecting mirror, 31 …… Attitude control member.

Claims (1)

[Scope of utility model registration request] 1. An optical scanning device in which a light irradiation unit including a laser light source, a rotary polygon mirror, and a reflection mirror is housed in a cover that is openable and closable and has a laser emission port formed therein. An optical scanning device, wherein the optical scanning device is attached to the cover so as to be rotatable according to an opening / closing posture of the cover, and is provided with a posture regulating member for regulating the rotation of the reflecting mirror.