JPH0453645Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an optical system dustproof mechanism that prevents dust from entering the body of a copying machine when cooling the optical system.

(Prior Art) FIG. 5 is an overall configuration diagram of a conventional document table moving type electrophotographic copying machine.

In FIG. 5, a movable contact glass (original platen) 2 on which an original is placed is provided at the upper part of a housing 1 of an electrophotographic copying machine, and a document holder 3 is arranged above the contact glass 2. ing. Inside the housing 1 are a document irradiation lamp 4, a reflector 5 surrounded by a frame 5a, and mirrors 6a, 6b, 6.
c, 6d and a lens assembly 7 are provided, and these constitute an optical system. Around the photoreceptor drum 8 that receives light from this optical system, a main charging device 9 and a blank lamp 1 are arranged in order in the rotational direction of the photoreceptor drum 8.
0, developing device 11, transfer device 12, separating device 1
3. A cleaning device 14 and the like are provided.

A conveyance roller 15 for conveying copy paper to the transfer device 12 is disposed downstream of the developing device 11 in the rotational direction of the photosensitive drum 8 and upstream of the transfer device 12. A copy paper cassette 18 in which copy paper 16 is stored is located upstream of the copy paper cassette 18.
is set. A paper feed roller 17 for feeding copy paper 16 is provided above the copy paper cassette 18 on the housing 1 side. Also,
On the upstream side of the conveyance roller 15 is a copy paper cassette 22 in which copy paper 20 is stored via a conveyance roller 19.
is set. A paper feed roller 21 for feeding copy paper 20 is provided above the copy paper cassette 22 on the housing 1 side. Also,
A bypass paper feed tray 24 is set upstream of the conveyance roller 19 via a conveyance roller 23.

A fixing device 26 is disposed on the downstream side of the separating device 13 in the copy paper conveyance direction via a conveyance belt 25, and a receiving tray 28 for receiving the copy paper via a discharge roller 27 is set downstream of the fixing device 26. ing.

Further, a fan motor 29 for cooling the internal device is provided near the reflector 5 and mirrors 6a and 6b inside the housing 1, and a ventilation hole 30 is provided on the wall near the fan motor 29 of the housing 1. There is.

Incidentally, in such an electrophotographic copying machine, a gap G is formed between the contact glass 2 and the housing 1 of the copying machine body, and the fan motor 29 is rotated to open the gap (cooling air passage) G and the optical passage of the frame 5a. 5b, the fan motor 29, and the air flowing through the ventilation holes 30 (air flowing in the direction indicated by arrow W) to cool the contact glass 2, the document irradiation lamp 4, and the like.

However, since the air that enters the machine through the gap G contains dust, etc., the dust adheres to the optical system such as the document irradiation lamp 4, reducing the amount of light and making the copied image dark. Tend. Furthermore, since the fan motor 29 rotates at a low speed even during copying standby, dust tends to adhere to the optical system and the like.

Therefore, as shown in Japanese Utility Model Application Publication No. 60-169631, for example, a copying machine is known in which a sealing member is provided on the lower surface of the end of the document table to prevent dust from the outside air from entering the machine during copying standby. There are, but
Providing such a sealing member makes it difficult to release the heat inside the machine.

(Purpose of the invention) This invention solves the above-mentioned technical problems, and prevents the optical system from becoming dirty by minimizing the intrusion of dust from the outside air, especially during copy standby, and also dissipates heat inside the machine, especially from the optical system and document table. It is an object of the present invention to provide an optical system dustproof mechanism for a copying machine that can sufficiently protect the optical system from dust.

(Structure of the invention) The invention is a copying machine in which a document table on which a document is placed moves relative to the optical system to perform copying operations, and a cooling air passage is provided between the document table and the main body housing. A dustproof member is provided at a predetermined position on the back surface of the document table so as to be interposed in the cooling air passage only during standby.

With this configuration, during copying standby, cooling air flows through the cooling air passage through the dustproof member, and during copying, cooling air flows directly through the cooling air passage without passing through the dustproof member.
Therefore, dust and the like are less likely to adhere to the optical system, and the document table, optical system, etc. are sufficiently cooled.

(Embodiment) FIG. 1 is an overall configuration diagram of an electrophotographic copying machine equipped with an optical dustproof mechanism according to an embodiment of the present invention.

In FIG. 1, components corresponding to those shown in FIG. 5 are given the same reference numerals and their explanations will be omitted.

In an electrophotographic copying machine of the document table movement type equipped with the optical system dustproof mechanism of the present invention, the document table on which the document is placed, that is, the contact glass 2 moves relative to the optical system (document irradiation lamp 4, etc.), and the copying operation is performed. This is a copying machine in which a gap G is provided between the contact glass 2 and the housing 1 as a cooling air passage. The feature of the optical system dustproof mechanism of the present invention is that the bristle brush B is inserted into the gap G as a dustproof member only during copying standby before the copying operation of the copying machine starts. It is provided at a predetermined position on the back surface of the contact glass 2. The above predetermined position is when the contact glass 2 is in the home position as shown in FIG.
This refers to one end of the back surface of the contact glass 2 to which the bristle brush B is attached so that the gap G can be closed.

Next, the operation of the optical system dustproof mechanism of the present invention will be explained with reference to FIGS. 1 to 4.

When the electrophotographic copying machine is powered on and enters a copying standby state, and the fan motor 29 rotates at a low speed,
Cooling air flows in the direction shown by arrow W in FIG. That is, this cooling air passes through the bristle brush B, the gap G, the optical path 5b, and the fan motor 29, and flows to the outside from the ventilation hole 30. As a result, the document irradiation lamp 4 and the contact glass 2 are mainly cooled down.

Next, the original is placed on the contact glass 2,
When a predetermined switch is operated to start the copying operation, the fan motor 29 rotates at high speed, and the contact glass 2 first moves in the direction of arrow a1 to the copying start position.
(Fig. 1), then move to the direction indicated by arrow a2.
It moves in the direction shown in FIG. 1, performs a copying operation, stops at the position shown in FIG. 4, and then returns to the home position shown in FIG. 3. When the contact glass 2 moves to the position shown in FIG. 4, or in the process of movement, the bristle brush B separates from the gap G provided between the contact glass 2 and the housing 1, and the cooling air flows in the direction indicated by the arrow W in FIG. Cooling air flows in the direction shown. That is, the cooling air in this case does not pass through the bristle brush B, but passes through the gap G, the optical path 5b, the fan motor 29, and flows to the outside from the ventilation hole 30. At this time, bristle brush B
Since there is no air resistance, the amount of cooling air increases and the cooling efficiency of the fan motor also increases.

According to this embodiment, when the copying operation begins and the contact glass 2 moves as shown in FIG. 2 or 4, the bristle brush B moves away from the gap G, the cooling air volume increases, and the contact The cooling efficiency of the glass 2 and the document irradiation lamp 4 is increased compared to when copying is on standby. Furthermore, since the bristle brush B is interposed in the gap G during copying standby, dust from the outside air is less likely to enter and accumulate in the optical system.

(Effect of the invention) As described above, according to the invention, during copying standby, cooling air flows through the cooling air passage through the dustproof member, and during copying, the cooling air flows directly into the cooling air passage without passing through the dustproof member. This allows the flow of dust from the outside air, especially during copying standby, to minimize the intrusion of dust from the outside air, thereby preventing stains on the optical system, and also ensuring sufficient heat dissipation within the machine, especially from the optical system and document table.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an electrophotographic copying machine with an original table moving type equipped with an optical system dustproof mechanism according to an embodiment of the present invention, and Fig. 2 shows a state in which the contact glass of the electrophotographic copying machine is moving. FIG. 3 is a schematic diagram of the main parts of the contact glass and optical system to explain the flow of cooling air during copying standby in the electrophotographic copying machine, and FIG. 4 is a perspective view showing the copying process in the electrophotographic copying machine. FIG. 5 is a block diagram of the main parts of a contact glass and an optical system for explaining the flow of cooling air during operation. FIG. 5 is a block diagram of the entire structure of a conventional document table moving type electrophotographic copying machine. 1...Housing, 2...Contact glass (original table), 4...Original irradiation lamp, 5...Reflector, 6a, 6b, 6c, 6d...Mirror, 7...
Lens assembly (optical system), B...bristle brush (dustproof member), G... gap (cooling air passage).

Claims (1)

[Scope of utility model registration request] This is a copying machine in which a document table on which a document is placed moves relative to the optical system to perform copying operations, and a cooling air passage is provided between the document table and the main body housing. An optical system dustproof mechanism for a copying machine, characterized in that a dustproof member is provided at a predetermined position on the back surface of the document table.