JPH06214317A - Optical system dust-proofing device for image forming device - Google Patents

Abstract

PURPOSE:To provide an optical system dust-proofing device capable of surely preventing dust or dirt from infiltrating into the optical system unit of an image forming device. CONSTITUTION:This device is attached to a 1st scanner 4 supporting a light source 3 and a 1st mirror 5 or a 2nd scanner 6 supporting 2nd/3rd mirrors 7 and 8 in order to prevent the dust or the dirt from infiltrating into the optical system unit 1 from the outside and prevent the contamination of an optical element; and it is provided with a shutter 9 consisting of the combination of an elastic member or each kind of plate material with an elastic member such as a spring; and the shutter 9 closes the air current exhaust port (or suction port) 1a of the optical system unit 1 when the 1st and the 2nd scanners 4 and 6 are at home positions, and opens the port (or suction port) 1a of the unit 1 when the 1st and the 2nd scanners 4 and 6 travel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical dustproof device for an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, an optical system portion is housed in a unit separated from an image forming portion in order to prevent the exposure optical system from being contaminated. FIG. 4 shows an example of the optical system unit portion of the copying machine.
Reference numeral 31 is an optical system unit, 31a is an airflow outlet of the unit, 31b is an airflow inlet of the unit, 32 is a contact glass, 33 is a light source such as a halogen lamp, and 34 is a first
Mirror, 35 is second mirror, 36 is third mirror, 37 is lens, 38 is fourth mirror, 39 is fifth mirror, 40 is sixth mirror, 41 is fan for cooling light source, 42 is filter, 43 is It is a photoconductor drum. The photosensitive drum 4
Around the circumference of 3, a charging device, a developing device, a transfer / separation device for forming an image by a known electrophotographic process,
Although a cleaning device, a fixing device, etc. are installed, they are not shown.

In an optical system unit 31 as shown in FIG. 4, a fan 41 is provided to cool a light source 33 such as a halogen lamp, and the fan 4 is used during an exposure operation.
1 rotates, a cooling airflow from the suction port 31b to the discharge port 31a is generated in the optical system unit 31, and the light source 33 and the contact glass 32 are cooled. A dustproof filter 42 is installed at the suction port to prevent external dust and the like from entering the unit when the fan is rotating.

[0004]

By the way, in an optical system such as a copying machine, a fan 41 is required to cool a light source 33 such as a halogen lamp, as shown in FIG. 31 cannot be a closed structure. Therefore, even if the filter 42 is installed at the suction port, the discharge port 31
There is a problem that dust or the like enters from a or other gaps to contaminate optical elements such as mirrors. Further, there is a problem that the filter 42 installed at the suction port also has a relatively coarse mesh and cannot prevent intrusion of fine dust and dirt. Although there is also a method of using a low heat source such as a fluorescent lamp as a light source without using a fan, there is a disadvantage in the size of the device and the cost with respect to the required light amount.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an optical dustproof device capable of reliably preventing dust and the like from entering an optical system unit of an image forming apparatus. To aim.

[0006]

According to another aspect of the present invention, there is provided an optical system dustproof device, which prevents dust and dirt from entering the optical system unit from the outside and prevents the optical element from being contaminated. A shutter that is mounted on a traveling body (first scanner) that supports a mirror or a traveling body (second scanner) that supports second / third mirrors, and is made of an elastic member or a combination of various plate materials and an elastic member such as a spring. And the shutter closes the airflow outlet or the air inlet of the optical system unit at the home position of the first and second scanners.
When the scanner is running, it operates so as to open the airflow outlet or the air inlet of the optical system unit.

According to another aspect of the present invention, there is provided an optical system dustproof device, which prevents dust from entering the optical system unit from the outside and prevents the optical element from being contaminated. It is equipped with a dustproof valve made of a sheet-shaped flexible elastic member installed, and the dustproof valve is configured to close the airflow inlet or outlet when the fan is stopped and open the airflow inlet or outlet when the fan is rotating. It is characterized by working.

[0008]

According to the optical system dustproof device of the first aspect,
At the home position of the second scanner, the shutter attached to the scanner closes the airflow outlet or the inlet of the optical system unit, so that it is possible to prevent dust and dirt from entering from the outside. In the optical dustproof device according to claim 2, a dustproof valve made of a sheet-like flexible elastic member is provided at the airflow outlet or the air inlet of the optical system unit, and the dustproof valve opens the airflow inlet or the outlet when the fan is stopped. Since it is closed, it is possible to prevent dust from entering from the outside.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments. FIG. 1 is a schematic configuration diagram of an optical system unit portion of a copying machine showing an embodiment of the present invention, FIG. 1A is a diagram showing a state when a scanner is at a home position,
(B) is a diagram showing a state when the scanner is moving, reference numeral 1 is an optical system unit, 1a is an airflow outlet of the unit, 1b is an airflow inlet of the unit, 2 is a contact glass, 3 is a halogen A light source such as a lamp, 5 is a first mirror, 7 is a second mirror, 8 is a third mirror, 10 is a lens,
Reference numeral 12 is a fourth mirror, 13 is a fifth mirror, 15 is a sixth mirror, 16 is a light source cooling fan, 17 is a dustproof filter, and 19 is a photosensitive drum.

In this embodiment, in order to prevent the optical elements in the optical system unit 1 from being soiled, the mirror optical element, which is particularly prone to dust and the like, is covered with the unit, and the optical system unit is externally exposed to the external light. In order to prevent the intrusion of dust and the like, a dustproof device is installed. That is, as shown in FIG. 1, the first mirror 5 is housed in the first mirror unit 4 having an optical path hole, and the first mirror unit 4
Together with the light source 3 are supported by a traveling body (not shown) to form a first scanner. The second mirror 7 and the third mirror 8 are housed in a second / third mirror unit 6 provided with an optical path hole and an opening, and the second / third mirror unit 6 is supported by a traveling body (not shown). And constitutes a second scanner. Further, the fourth mirror 12 and the fifth mirror 13 are housed in the fourth / fifth mirror unit 11 provided with the optical path hole, and the sixth mirror 15 is housed in the sixth mirror unit 14 provided with the optical path hole. There is. If the fourth / fifth mirror unit 11 has a variable magnification function, it is supported by a movable body for variable magnification.

FIG. 2 shows the second / third mirror unit 6 of FIG.
FIG. 3 is a diagram showing a discharge port portion of the optical system unit 1,
(A) shows the state when the first and second scanners are in the home position, and (b) shows the state when the scanner is moving. As shown in FIG. 2, in addition to the optical path holes 6b and 6c, the second / third mirror unit 6 of the second scanner is provided with an opening 6a for passing an air flow.
a is provided on the wall surface of the optical system unit 1 that faces the discharge port 1a. A shutter 9 that can be opened and closed is attached to the outside of the wall surface provided with the opening 6a. The shutter 9 is made of a combination of a plate material and an elastic member such as a hinge and a spring.
Although it is swingably supported by a, elastic members such as coil springs and leaf springs that apply elastic force in the opening direction to the plate member are attached to the hinge portion. For this reason,
As shown in FIG. 2B, when the second scanner is moving (a position other than the home position), the shutter 9 is opened by the elastic force of a spring or the like. However, FIG.
As shown in (a), if the home position of the second scanner is set at a position close to the wall surface of the optical system unit 1 where the discharge port 1a is provided, the shutter 9 is pressed against the wall surface and closed. And the discharge port 1a and the second /
The opening 6a of the third mirror unit 6 is closed by the shutter 9.

As described above, the shutter 9 attached to the second / third mirror unit 6 of the second scanner has the airflow of the optical system unit 1 when the scanner is at the home position (when the exposure operation is stopped). Close the outlet 1a,
Airflow outlet 1 of optical system unit 1 when the scanner is running
2a, the airflow outlet 1a of the optical system unit 1 is always closed by the shutter 9 when the scanner is at the home position (when the exposure operation is stopped) as shown in FIG. Since it is in the dislocated state, it is possible to prevent dust and dirt from entering from the outside. Further, during the exposure operation, the scanner runs and moves away from the home position, so that the shutter 9 is opened as shown in FIG. 2B, and the cooling airflow from the fan 16 is a mirror unit as shown by an arrow in the figure. It also passes through the inside and is discharged from the discharge port 1 a of the optical system unit 1. In addition, in the illustrated example, 1
Although a is the airflow outlet, 1a is the airflow inlet if the direction of the airflow by the fan 16 is opposite. When 1a is used as the suction port, the dustproof filter is attached to the outer wall side.

Next, FIG. 3 is a diagram showing a fan and an airflow inlet of the optical system unit 1 of FIG. 1, (a) showing a state when the fan is stopped, and (b) showing a fan rotating. It is a figure which shows the state of. As shown in FIG. 3, a dustproof filter 17 is attached to the outside of the airflow inlet 1b of the optical system unit 1, and a sheet-shaped flexible elastic member (mylar or other resin) is attached to the inside of the airflow inlet 1b. A dustproof valve 18 made of sheet, paper, etc. is installed. The dustproof valve 18 is vertically divided into two parts, and the upper end of the upper valve part and the lower end of the lower valve part are fixed to the upper and lower edges of the intake port 1b, respectively, so that the central part is opened and closed. Therefore, when the fan 16 is stopped, the dustproof valve 18 closes the airflow inlet 1b by the elastic force as shown in FIG. 3A, but when the fan 16 is rotated, the dustproof valve 18 shown in FIG. As described above, the dustproof valve 18 is opened vertically by the inflow of the airflow, and the airflow inlet 1b is opened.

As described above, the dustproof valve 18 operates to open the airflow inlet 1b when the fan 16 rotates and close the airflow inlet 1b when the fan 16 is stopped.
When 6 is stopped, the airflow inlet 1b is sealed by the dustproof valve 18, and it is possible to prevent dust from entering from the outside. In the illustrated example, 1b is the airflow inlet, but if the direction of the airflow by the fan 16 is opposite, 1b is used.
Is the airflow outlet. Further, in this case, the dustproof valve is installed outside the opening.

Since the embodiment shown in FIG. 1 is provided with the shutter 9 shown in FIG. 2 and the dustproof valve 18 shown in FIG. 3, the image forming apparatus is stopped, that is, the scanner is at the home position. When the fan 16 is stopped, the airflow inlet 1b is closed by the dustproof valve 18 and the airflow outlet 1a is closed by the shutter 9 as shown in FIG. It is possible to prevent dust and dirt from entering. Further, during the exposure operation, the scanner runs and the fan 16 rotates, so that the airflow inlet 1b and the airflow outlet 1a are opened as shown in FIG. 1B, and the airflow is an optical system unit as shown by an arrow in the figure. Since the light passes through the inside of 1, the light source 3 and the contact glass 2 are effectively cooled as in the conventional case. It should be noted that dust and dirt may enter through the gaps other than the airflow inlet 1b and the airflow outlet 1a, but since it is a small amount, it causes almost no problem. Also in this case, the respective mirrors are arranged in the mirror unit 4, 6, 11, 1 as shown in FIG.
If it is stored in 4, the dust will hardly adhere to the mirror.

[0016]

As described above, in the optical dustproof device according to the first aspect of the present invention, when the first and second scanners are at the home position, the shutter attached to the scanner is the airflow outlet or the inlet of the optical system unit. Since it is closed, it is possible to prevent dust and dirt from entering from the outside. Therefore, it is possible to solve the problem of contamination of the optical element due to infiltration of dust and dirt. In the optical dustproof device according to claim 2, a dustproof valve made of a sheet-like flexible elastic member is provided at the airflow outlet or the air inlet of the optical system unit, and the dustproof valve opens the airflow inlet or the outlet when the fan is stopped. Since it is closed, it is possible to prevent dust from entering from the outside. Therefore, it is possible to solve the problem of contamination of the optical element due to infiltration of dust and dirt.

[Brief description of drawings]

1A and 1B are schematic configuration diagrams of an optical system unit portion of a copying machine showing an embodiment of the present invention, FIG. 1A showing a state in which a scanner is at a home position, and FIG. It is a figure which shows the state when moving.

FIG. 2 is a cross-sectional view of essential parts showing discharge ports of the second / third mirror unit and the optical system unit shown in FIG.
FIG. 4B is a diagram showing a state when the scanner is at the home position, and FIG. 8B is a diagram showing a state when the scanner is moving.

3A and 3B are cross-sectional views of a main part showing a fan and an air intake port of the optical system unit of FIG. 1, in which FIG. 3A is a view showing a state when the fan is stopped, and FIG. 3B is a state when the fan is rotating. FIG.

FIG. 4 is a schematic configuration diagram showing an example of an optical system unit portion of a conventional copying machine.

[Explanation of symbols]

 1 ... Optical system unit 1a ... Airflow outlet 1b ... Airflow inlet 2 ... Contact glass 3 ... Light source 4 ... 1st mirror unit 5 ... 1st mirror 6 ... Second / third mirror unit 7 ... second mirror 8 ... third mirror 9 ... shutter 10 ... lens 11 ... fourth / fifth mirror unit 12 ... fourth mirror 13 ... Fifth mirror 14 ... Sixth mirror unit 15 ... Sixth mirror 16 ... Light source cooling fan 17 ... Dust filter 18 ... Dust valve 19 ... Photosensitive drum

Claims (2)

[Claims] 1. An image forming apparatus having a fan for cooling a light source in an optical system unit accommodating an exposure optical system, which prevents dust and dirt from entering the optical system unit from the outside and stains optical elements. A device (first scanner) or a second / third third device for preventing the light source, which supports the light source and the first mirror.
Mounted on a traveling body (second scanner) that supports the mirror of the second scanner, and has a shutter made of an elastic member or a combination of various plate materials and an elastic member such as a spring, and the shutter is the home position of the first and second scanners. Occasionally, the airflow outlet or inlet of the optical system unit is closed,
An optical dustproof device for an image forming apparatus, which operates so as to open an airflow outlet or an air inlet of an optical system unit when the scanner is running. 2. An image forming apparatus having a fan for cooling a light source in an optical system unit accommodating an exposure optical system, which prevents dust and dirt from entering the optical system unit from the outside and stains optical elements. A device for preventing air pollution, comprising a dustproof valve made of a sheet-shaped flexible elastic member installed at the airflow inlet or outlet of the optical system unit, and the dustproof valve is provided when the fan is stopped. Is closed, and when the fan rotates, it operates so as to open an airflow inlet or an outlet, and an optical dustproof device for an image forming apparatus.