JPH032775A - Shutter device for laser beam printer - Google Patents

Abstract

PURPOSE:To precisely hold a shutter at a prescribed position by providing a stopper which regulates the shutter so that the center of the gravity of the shutter is positioned on an optical axis side with respect to a plumb line passing the center of a shaft when the shutter is positioned where the optical axis of laser beams is opened. CONSTITUTION:The stoppers 37 which regulates the position of the shutter 33 is provided so that the center of the gravity of the shutter 33 is positioned on the optical axis side with respect to be plumb line passing the center of the shaft 34 when the shutter 33 is positioned where the optical axis of the laser beams is opened. Therefore, in a state that a laser beam printer lid 2 is closed, the motion of the shutter 33 is interrupted by the stopper 37 at the position where the optical axis of the laser beam is opened, and in a state that the lid 2 is opened, the motion of the shutter 33 is interrupted at a position where the optical axis of the laser beams is shielded. Thus the motion of the shutter 33 is precisely regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shutter device for shielding the optical axis of laser light in an optical system unit of a laser beam printer.

[Prior Art] Laser beam printers, which have recently been widely used in office automation equipment, have a main body and a lid rotatably attached to the main body to form a housing, and the main body has a photoreceptor, a developing unit,
Some devices are equipped with a transfer unit and the like, and have an optical system unit equipped with a laser output element on the lid so that the lid can be rotated and opened to allow inspection of the inside of the main body. This type of printer is designed to avoid the risk of irradiating the operator with the laser emitted from the laser light output element of the optical system unit when the lid is opened for maintenance and inspection work. A shutter is provided to block the optical path.

A conventional laser beam printer employs a shutter device having the structure shown in FIGS. 8 and 9.

Namely. In the figure, 1 is a main body, and 2 is a lid provided to cover the upper open part of the main body 1 and can be opened and closed by a pivot 3. The main body 1 and the lid 2 constitute a housing. In main body 1,
A photosensitive drum 4, a developing unit 5, a transfer unit 6, a static eliminating unit 7, a charging unit 8, a fixing roller 9, a paper feed cassette 10, and a discharge cassette 11 are provided. The lid 2 is provided with an optical system unit 12 equipped with a laser light output element. The lid 2 is provided with a shutter 3 on the optical axis of the laser beam. As shown in FIGS. 10 and 11, the shutter 13 is rotatably suspended with its upper end supported by a pivot 14.

In this laser beam printer, when the lid 2 is closed, the shutter 13 is in a position where it blocks the optical axis of the laser beam, as shown in FIGS. 8 and 10. When inspecting the inside of the main body 1, such as when a paper jam occurs, open the opening of the main body 1 by rotating the lid 2 upward about the pivot 3 as shown in FIGS. 9 and 11. do. In this case, depending on the inclination of the lid 2, the shutter 13 rotates under its own weight and is displaced to a position where it blocks the optical axis of the laser beam.

[Problems to be Solved by the Invention] However, according to such a conventional shutter device, since the shutter 13 is simply rotatably suspended from the pivot shaft 14, it is difficult to access the laser beam printer from the outside. It is in a state where it easily vibrates due to applied vibrations and shocks. For this reason, when recording is performed with M2 closed, the shutter 13 may move due to external vibration or impact, blocking the optical axis of the laser beam and adversely affecting recording. Also, lid 2
When the shutter 13 is opened, the shutter 13 may move due to external vibration or impact, opening the optical axis of the laser beam and irradiating the worker with the laser beam.

The present invention was made based on the previous situation, and is highly reliable because it securely holds the shutter in a predetermined position depending on the open/closed state of the lid of the laser beam printer, and prevents it from accidentally moving due to external vibrations or shocks. An object of the present invention is to provide a shutter device for a laser beam printer.

[Means for Solving the Problems] In order to achieve the above object, the laser beam printer of the present invention has a lid rotatably provided on the main body, and an optical system unit equipped with a laser beam output element is provided on the lid. In the laser beam printer, the laser beam printer is rotatably suspended and supported by a pivot, and when the lid is opened, the optical axis of the laser beam output from the laser output element is blocked, and when the lid is closed, the laser beam is a shutter for opening the optical axis of the laser beam; and a shutter for opening the optical axis of the laser beam; The shutter is characterized by comprising a stopper that regulates the position of the shutter.

Also. The shutter device for a laser beam printer of the present invention is a laser beam printer in which a main body is rotatably provided with a lid, and an optical system equipped with a laser beam output element is provided on the lid. a shutter that is supported and blocks the optical axis of the laser beam output from the laser output element when the lid is opened and opens the optical axis of the laser beam when the lid is closed; and a stopper for regulating the position of the shutter such that the center of gravity of the shutter is located on the opposite side of the optical axis with respect to a vertical line passing through the center of the pivot axis when the shutter is in a position to block the optical axis of the shutter. It is characterized by

The stopper may preferably be provided with a guide surface for guiding the shutter when the shutter pivot is assembled into a receiving member that removably supports the shutter pivot.

[Function] In the shutter device of the present invention, when the lid of the laser beam printer is closed due to the former configuration, the shutter is prevented from moving by the stopper at the position where the optical axis of the laser beam is opened, and is protected against external vibrations and shocks. The stopper prevents movement t:·i at a position where the optical axis of the light is shielded, and does not move due to external vibrations or shocks. Since these stoppers receive the shutter at the front in the direction in which the rotational force is applied by the shutter's own weight, movement of the shutter can be reliably suppressed with a simple configuration.

Further, since the stopper is provided with a row/5 guide surface for guiding the shaft of the shutter, the shutter can be easily assembled.

[Example) Embodiments of the present invention will be described below with reference to the drawings.

1 to 7 show one embodiment of the present invention.

1 and 2 show a laser beam printer equipped with a shutter device according to the invention. In this figure, the eighth
The same parts as in the figures and FIG. 9 are designated by the same reference numerals.

The optical system unit 12 provided with the shutter of the present invention will be explained with reference to FIG.

In the figure, 21 is a laser diode which is a laser light output element;
22 is a collimator lens, 23 is a cylindrical lens, 24 is a plano-convex lens, 25 is a polygon mirror, 26 is a first mirror, 27 is a second mirror, 28 is a third mirror 29
is a correction lens.

The polygon mirror 25 has a hexagonal shape, for example, and is rotated by a motor (not shown). In addition, the laser diode 23
is provided on a circuit board (not shown) provided in the unit main body, and other parts are provided in the unit main body. Then, the laser light output from the laser diode 21 is transmitted to each lens 2.
2 to 24 and is reflected by the first mirror 26, the light is emitted onto the reflective surface of the polygon mirror 25 and reflected. Thereafter, the laser beam is reflected by the second mirror 27 and the third mirror 28, passes through a correction lens, and is focused on the surface of the photosensitive drum 4 to form an image. Incidentally, the polygon mirror 25 is rotated by a motor in the optical path of the laser beam, and the first scan is repeated.

The shutter device of the present invention includes, for example, a cylindrical lens 23 and a plano-convex lens 24 in this optical system unit 12.
provided between. As shown in FIGS. 4 and 5, a pair of shutter receiving members 32 are provided on the unit main body at intervals along the optical axis of the laser beam. This receiving member 32 has a receiving portion 32a formed at its upper end. A shutter 33 is supported by a pivot shaft 34 on this receiving member 32 . The shutter 33 has a fan shape, and is attached with a pivot 34 passing through the key part of the fan shape in a direction perpendicular to the shutter 33. The pivot 34 is horizontal and the receiving part 3 of the receiving member 32 is
Kake is listed in 2a. As a result, shutter 3
3 is rotatably suspended from a pivot 34.

Further, a notch 35 having a predetermined width is formed on the arcuate outer circumference of the shutter 33, and a notch 36 for opening the optical axis of the laser beam is formed on one side edge. Note that the center of gravity G of the shutter 33 is, for example, the side edge 3 of the notch 35 on the optical axis side.
5a and the center of the pivot 34. Furthermore, a stopper 37 is provided on the unit body. This stopper 37 is located inside the notch 35 of the shutter 35 and comes into contact with the side edges 35a, 35b of the notch 35 to restrict rotation of the shutter 33. That is, when the lid 2 of the laser beam printer is closed, the stopper 37 is located on the side edge 35a of the notch 35 located on the optical axis side of the laser beam.
The position of the shutter 33 is regulated so that the center of gravity O of the shutter 33 is located on the optical axis side with respect to the vertical line XX passing through the center of the pivot 34.

At this time, the notch 36 of the shutter 33 is located at a position where the optical axis of the laser beam escapes, opening this optical axis. Further, when the lid 2 of the laser beam printer is open, the stopper 37 comes into contact with the side edge 35a of the notch 35 located on the side opposite to the optical axis side of the laser beam, and the center of gravity G of the shutter 33 is shifted from the axis 34. The position of the shutter 33 is regulated so that it is located on the opposite side of the optical axis from the vertical line XX passing through the center. At this time, the shutter 33 blocks the optical axis of the laser beam.

Note that a guide surface 37a is formed on the last collar 37 and is inclined toward the optical axis so as to face the pivot 34.

The operation of the shutter device having such a configuration will be explained.

As shown in FIG. 1, when the lid 2 of the laser beam printer is closed, the shutter 33 is in a state where the pivot 32 is suspended, and the notch 36 is in a position to open the optical axis of the laser beam. . The shutter 33 and the stopper 37 have a relationship as shown in FIG. Since the stopper 37 is in contact with the side edge 35a of the notch 35 of the shutter 33, the center of gravity G of the shutter 33 is on the optical axis side of the laser beam, that is, on the counterclockwise side with respect to the vertical line XX passing through the center of the pivot 34. It is located in Therefore, the shutter 33 attempts to rotate clockwise in the figure due to its own weight, but the side edge 35a of the notch 35 hits the right side edge of the stopper 37 in the figure, causing a drag Fa.
While receiving the force, it is prevented from rotating and stops. In this case, the notch 36 of the shutter 33 opens the optical axis of the laser beam, allowing the laser beam to pass through. Therefore, laser light can be focused on the photosensitive drum 4. Here, if an inertial force is generated in the shutter 33 due to vibrations or shocks applied from outside the laser beam printer, it is possible to maintain a stationary state within a range that does not exceed the drag force Fa. This allows the shutter 33 to keep the optical axis of the laser beam open.

Next, in order to perform maintenance and inspection work, as shown in Figure 2,
2 is opened and rotated upward, the optical system unit 12 also moves upward together. At this time, as shown in FIG. 5, the stopper 37 provided on the optical system unit 12 rotates and becomes inclined. Further, the shutter 33 rotates around the pivot 34 while maintaining the suspended state according to the opening angle of the lid 2, and is displaced to a position where it blocks the optical axis of the laser beam. The shutter 33 and the stopper 37 have the following relationship. The stopper 37 is attached to the side edge 3 of the notch 35 of the shutter 33.
5b, the center of gravity G of the shutter 33 is located on the side opposite to the optical axis of the laser beam, that is, on the clockwise side from the vertical line XX passing through the center of the pivot 34. shutter 3
3 attempts to rotate counterclockwise in the drawing due to its own weight, but the side edge 35b of the notch 35 hits the left side edge of the stopper 37 in the drawing, receives a drag force Fb, and is prevented from rotating and stops. Here, if an inertial force is generated in the shutter 33 due to vibration or shock applied from the outside, it is possible to maintain a stationary state within a range that does not exceed the drag force Fb. This makes it possible to maintain a state in which the shutter 33 blocks the optical axis of the laser beam.

The work when assembling the shutter 33 is shown in Figures 6 and 7.
The diagram will be explained.

The receiving member 32 is fixed to the main body of the optical system unit 12, and when assembling the shutter 32, the pivot 34 is fitted into the receiving portion 32a of the receiving member 32 from above to support the shutter 33. At this time, as shown in FIG. 6, the shutter 33 descends with its center of gravity G positioned on the vertical line XX. As the shutter 33 is lowered, the side edge 35a of the notch 35 of the shutter 33 moves toward the inclined guide surface 37 of the stopper 37 provided in the optical system unit 12.
a, and guided by this inclined guide surface 37, the shutter 33 is rotated counterclockwise about the pivot 34 and installed. Therefore, the shutter 33 can be combined with the stopper 37 in a transparent and reliable manner with various modifications.

For example, in the embodiment, the stopper that restricts the movement of the shutter when the lid is closed and the stopper that restricts the movement of the shutter when the lid is opened are provided in common, but they may be provided separately.

[Effects of the Invention] As explained above, the shutter device of the laser beam printer of the present invention is provided with a stopper that restricts the movement of the shutter that opens the optical axis of the laser beam when the lid is closed. , the shutter does not move due to external vibrations or shocks, making it possible to perform highly reliable recording.

Further, according to the shutter device of the laser beam printer of the present invention, since the stopper is provided to restrict the movement of the shutter that blocks the optical axis of the laser beam when the lid is opened,
Nyatta does not move due to external vibrations or shocks,
It is highly reliable and allows you to perform maintenance and inspection tasks with peace of mind by opening the lid.

Since the stopper prevents the shutter from rotating due to its own weight as the lid is opened and closed, it is possible to reliably restrict the movement of the shutter while having a simple structure.

Further, since a guide surface is formed on the stopper to guide the shutter when the shutter is assembled, assembly can be carried out smoothly and reliably.

[Brief explanation of the drawing]

1 to 7 show an embodiment of the present invention, FIGS. 1 and 2 are diagrams showing a schematic configuration of a laser beam printer equipped with a shutter device of the present invention, and FIG. 3 is a diagram showing an optical system. 4 and 5 are diagrams showing the shutter device, FIGS. 6 and 7 are diagrams showing the operation of assembling the shutter device, and FIGS. 8 and 9 are diagrams showing the conventional shutter device. It is. DESCRIPTION OF SYMBOLS 1... Main body, 2... Lid, 12... Optical system unit, 33... Shutter, 34... Pivot, 37... Stopper. Applicant's representative Patent attorney Takehiko Suzue 1-m-this case-ji 12-11-syllable unit 33-11-sy1tsuk37--su) Tsuba・Fig. 1Fig. 2Fig. Diagram: Funeral diagram Diagram:

Claims (3)

[Claims] (1) In a laser beam printer in which a lid is rotatably provided on the main body, and an optical system unit equipped with a laser beam output element is provided on the lid, the lid is rotatably suspended and supported by a pivot, and the lid is opened. a shutter that blocks the optical axis of the laser beam output from the laser output element when the lid is closed and opens the optical axis of the laser beam when the lid is closed; and a position where the shutter opens the optical axis of the laser beam. a stopper for regulating the position of the shutter so that the center of gravity of the shutter is located on the optical axis side with respect to a vertical line passing through the center of the pivot axis when the shutter is located at . (2) In a laser beam printer in which a lid is rotatably provided on the main body, and an optical system unit equipped with a laser beam output element is provided on the lid, the lid is rotatably suspended and supported by a pivot, and the lid is opened. a shutter that blocks the optical axis of the laser beam output from the laser output element when the lid is closed and opens the optical axis of the laser beam when the lid is closed; and a position where the shutter blocks the optical axis of the laser beam. and a stopper for regulating the position of the shutter so that the center of gravity of the shutter is located on the opposite side of the optical axis with respect to a vertical line passing through the center of the pivot axis. shutter device (3) The shutter device for a laser beam printer according to claim 1 or 2, wherein the stopper is provided with a guide surface for guiding the shutter when the shutter pivot is assembled into the receiving member that removably supports the shutter pivot.