JP3076193B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to an image forming apparatus such as a facsimile machine.

[0002]

2. Description of the Related Art FIG. 33 shows a structure for attaching a contact glass to a frame in a conventional copying machine.
In a conventional copier, a plurality of rubber plates 701 are fixed on a frame 700, and a contact glass 702 is placed on the rubber plate 701 with the contact glass 702 placed thereon.
Are attached to the frame 700.

[0003]

In the copying machine as described above, since the outside air containing dust enters between the frame 700 and the contact glass 702, the inner surface of the contact glass and the optical system for exposure are easily stained. Therefore, there is a problem that image deterioration such as burn-in of the copy, fog, etc. occurs, and the toner consumption increases more than necessary.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which can prevent outside air from entering between a frame member and a contact glass, and can prevent image deterioration and increase in toner consumption.

[0005]

A first image forming apparatus according to the present invention comprises: a contact glass on which a document is placed;
In an image forming apparatus in which a seal member is interposed between a frame member to which a contact glass is attached, a plurality of upwardly projecting height positioning portions are formed on an upper surface of the frame member, and the seal member is positioned at a height. The contact glass is mounted on the frame member while being placed on the top surface of the frame member so as to pass through the outside or inside of the portion, and the contact glass is pressed against the seal member and received by the height positioning portion. It is characterized by being. For example, an endless seal member is used as the seal member.

A second image forming apparatus according to the present invention is directed to an image forming apparatus in which a seal member is interposed between a contact glass on which a document is placed and a frame member to which the contact glass is attached. A plurality of upwardly projecting height positioning portions are formed on the upper surface, and a notch portion in which the height positioning portion is fitted at a position corresponding to each height positioning portion is formed on the sealing member, As the height positioning part is fitted into the notch part of the member,
A seal member is placed on the upper surface of the frame member, and the contact glass is attached to the frame member in a state where the contact glass is pressed against the seal member. For example, an endless seal member is used as the seal member.

A third image forming apparatus according to the present invention is directed to an image forming apparatus in which a seal member is interposed between a contact glass on which a document is placed and a frame member to which the contact glass is attached. A plurality of upwardly projecting height positioning portions are formed on the upper surface, and the seal member is configured by a plurality of seal member structures corresponding to portions between adjacent height positioning portions on the frame member upper surface, Each of the seal member structures is fitted into a corresponding portion of a portion between adjacent height positioning portions on the upper surface of the frame member, and the contact glass is pressed against the seal member and received by the height positioning portion. In this state, the contact glass is attached to the frame member.

[0008]

In the first, second or third image forming apparatus according to the present invention, since the sealing property between the frame member to which the contact glass is attached is improved, outside air enters from between the frame member and the contact glass. Can be prevented. Therefore, it is possible to prevent image deterioration and increase in toner consumption.

[0009]

[0010]

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

FIG. 1 shows the overall configuration of an electrophotographic copying machine.

The copying machine includes a copying machine main body, an exposure optical system provided in an upper part of the copying machine main body, a developing unit provided below the exposure optical system in the copying machine main body, and a recording paper transport mechanism. It consists of a part.

The developing section has a photosensitive drum 1.
Although not shown, a charger for charging the photosensitive layer on the surface of the photosensitive drum 1 is provided around the photosensitive drum 1, and the electrostatic latent image formed on the photosensitive layer is visualized as a toner visible image. Developing device, transfer discharger for transferring the toner image formed on the photosensitive layer to recording paper, separation discharger for separating recording paper from photosensitive drum 1, surface of photosensitive drum 1 after transfer A cleaning device or the like for removing the toner remaining in the image forming apparatus is disposed.

The optical system for exposure is built in a sealed casing 10. The sealed casing 10 includes a case 11 having an exposure window on an upper surface, and a contact glass 12 attached to the case 11 so as to seal the exposure window.
Consists of

The exposure optical system section includes a first optical system traveling body 2.
0, the second optical system traveling body 30 and the lens unit 40.

The first optical system traveling body 20 includes a pair of exposure lamps 21 and 22 for exposing and scanning an image of a document placed on the contact glass 12 and a first mirror 23 for reflecting light reflected from the document. It has.

The second optical system traveling body 30 includes second and third mirrors 31 for guiding the light reflected by the first mirror 23 of the first optical system traveling body 20 to the lens unit 40.
32.

The lens unit 40 has a lens 41 on which light reflected by the third mirror 32 of the second optical system traveling body 30 is incident, and a lens for guiding light emitted from the lens 41 to the surface of the photosensitive drum 1. Fourth, fifth and sixth mirrors 4
2, 43 and 44 are provided. When the light emitted from the lens unit 40 is irradiated on the photosensitive drum 1, an electrostatic latent image is formed on the photosensitive layer on the surface of the photosensitive drum 1.

The first optical system traveling body 20 and the second optical system traveling body 30 are reciprocated in the left-right direction by a scan motor (not shown). The second optical system traveling body 30 moves at a speed that is half the speed of the first optical system traveling body 20 and that is a half of the moving distance of the first optical system traveling body 20. The description of the recording paper transport mechanism will be omitted.

FIG. 2 shows a sealed casing 10 in which an optical system for exposure is built.

The sealing casing 10 has an exposure window 3 on its upper surface.
A case 11, a contact glass 12 attached to the case 11 so as to close the exposure window 3, and a rectangular frame-shaped sealing member 13 interposed between the case 11 and the peripheral edge of the lower surface of the contact glass 12. It is configured.

The case 11 comprises a rectangular parallelepiped case body 51 having an open upper surface, and a lid 52 having an exposure window 3. The lens unit 40 is provided on the bottom of the case body 51.
A slit 54 for guiding light from the photosensitive drum 1 to the photosensitive drum 1 is formed. The slit 54 is sealed by the glass plate 2 (see FIG. 1). Two notches 55 are formed at the upper ends of the outer surfaces of the front and rear side walls of the case body 51. A screw hole 56 is formed at the place where the notch 55 is formed on the front and rear side walls of the case body 51.

On the upper end surfaces of the front and rear side walls of the case body 51, two positioning projections 57 are formed. In this example, a guide rail 58 having an L-shaped cross section extending in the longitudinal direction for guiding the first and second optical system traveling bodies 20 and 30 is attached to the inner surfaces of the front and rear side walls of the case main body 51. Have been. This guide rail 58
Also has a function as a reinforcing member of the case body 51. On the right side wall of the case main body 51, a connector 60 for connecting an electric cord extending from a device in the optical system for exposure to an electric cord 59 outside the case main body 51 is attached. The connector 53 attached to the external electric cord 59 is provided with a sealing mechanism for preventing the sealing performance of the case main body 51 from being impaired by the connector 60.

The periphery of the exposure window 3 of the lid 52 is formed so that the height of the upper surface is lower than the left and right ends of the lid 52. A portion of the lid 52 around the exposure window 3 where the height is low is referred to as a rectangular frame-shaped portion. At the front and rear edges of the lower surface of the lid 52, lower projections 61 fitted into the notches 55 are provided at positions corresponding to the notches 55 of the case body 51.
Are formed respectively. Each lower protrusion 61 has a screw insertion hole 62. A groove-shaped notch 63 into which the protrusion 57 is fitted is formed at a position corresponding to the protrusion 57 of the case body 51 at the front and rear edges of the lower surface of the lid 52.

A rectangular frame-shaped seal member 13 is mounted on the upper surface of the rectangular frame portion around the exposure window 3 of the lid 52. The contact glass 12 is placed on the seal member 13. Then, the contact glass 12 is attached to the lid 52 in a state where the seal member 13 is pressed by the contact glass 12 by a fixture (not shown).

The lid 52 has a projection 61 formed on the case body 5.
The notch 63 is fitted into the notch 55 and the notch 63 is fitted into the projection 57 of the case body 51.
After being placed on the top 1, a screw (not shown) is screwed into a screw hole 56 of the case main body 51 from a screw insertion hole 62 of each projection 61, thereby being fixed to the case main body 51.

The case body 51 and the lid 5 as described above.
2 is produced, for example, by integrally molding a synthetic resin. The case body 51 and the lid 52 may be manufactured by processing a sheet metal.

FIG. 3 shows a detailed configuration of the first optical system traveling body 20.

The first optical system traveling body 20 includes a slit plate 24 having a slit 25 extending in the front-rear direction, a pair of exposure lamps 21 and 22 extending in the front-rear direction, and a first mirror 23.
It has. As the exposure lamps 21 and 22, a hot cathode type fluorescent lamp is used here. As the exposure lamps 21 and 22, other types of fluorescent lamps such as a cold cathode type may be used.

A part around each of the fluorescent lamps 21 and 22 includes:
Planar heating elements 26 and 27 extending in the length direction are attached. The first optical system traveling body 20 includes a fluorescent lamp 2.
A temperature sensor 28 for detecting the ambient temperature of the first and the second 22 is provided. A light amount sensor 29 for detecting the amount of light reflected from the document is provided.

The light emitted from both fluorescent lamps 21 and 22 is
The light is reflected by the original on the contact glass 12. This reflected light is incident on the first mirror 23 through the slit 25. The light that has entered the first mirror 23 is reflected by the first mirror 23 and sent to the second optical system traveling body 30.

FIG. 5 shows the illuminance characteristics on the document surface with respect to the position of the fluorescent lamps 21 and 22 in the length direction. FIG. 6 shows the illuminance characteristics on the surface of the photosensitive drum 1 with respect to the position in the length direction of the fluorescent lamps 21 and 22 when a slit plate having a slit having a uniform width in the length direction is used. The illuminance on the document surface with respect to the length direction positions of the fluorescent lamps 21 and 22 is substantially constant except for both ends as shown in FIG. However, as shown in FIG. 6, the illuminance on the surface of the photosensitive drum 1 after passing through the lens 41 decreases toward the both ends in the length direction of the fluorescent lamps 21 and 22, as shown in FIG. .

In order to make the illuminance on the surface of the photosensitive drum 1 after passing through the lens 41 constant in the longitudinal direction of the fluorescent lamps 21 and 22, the slit 25 of the slit plate 24 is used.
As shown in FIG. 4, the width of the central portion in the length direction is the smallest, and the width is increased toward both ends. FIG. 7 shows the illuminance characteristics on the surface of the photosensitive drum 1 with respect to the length direction positions of the fluorescent lamps 21 and 22 after the illuminance has been corrected by the slit 25 as shown in FIG.

FIG. 8 shows the relationship between the temperatures of the fluorescent lamps 21 and 22 and the illuminance on the document surface. FIG. 9 shows the relationship between the temperatures of the fluorescent lamps 21 and 22 and the surface potential of the photosensitive drum 1 when a white original is exposed. FIG. 10 shows the temperatures of the fluorescent lamps 21 and 22 and the photosensitive drum 1 when the gray document was exposed.
Shows the relationship with the surface potential.

As can be seen from these figures, the fluorescent lamp 2
The illuminance on the document surface by the light sources 1 and 22 changes sensitively according to the temperature change of the fluorescent lamps 21 and 22. In particular, fluorescent light 21,
When the temperature of 22 is low, the illuminance on the document surface is insufficient,
The photosensitive drum surface potential increases.

Therefore, in this embodiment, each of the fluorescent lamps 21 and
The temperature of each of the fluorescent lamps 21 and 22 is kept constant by controlling the driving of the planar heating elements 26 and 27 attached to the 22 based on the temperature detected by the temperature sensor 28.

Further, by controlling the duty ratio of the driving pulses of the fluorescent lamps 21 and 22 based on the light amount detected by the light amount sensor 29, a suitable light amount can be obtained.

In the above embodiment, since the optical system for exposure is built in the closed casing 10, the influence of external temperature and humidity changes is reduced. Further, since dust from outside does not enter, it is possible to prevent adverse effects due to dust.

FIG. 11 shows a copier in which the exposure optical system is built in the closed casing 10 and a copier in which the exposure optical system is not built in the closed casing. The illuminance on the surface of the photosensitive drum with respect to the position in the length direction of the fluorescent lamps of both copying machines immediately after the air conditioner is turned on during continuous copying is shown.

FIG. 11A shows the characteristics of a copier in which the optical system for exposure is built in the closed casing 10, and FIG. 11B shows the characteristic of the optical system for exposure built in the closed casing. This shows the characteristics for a copying machine that does not have the same. From this figure, it can be seen that in a copying machine in which the exposure optical system is not built in the closed casing, the illuminance on the surface of the photosensitive drum is not constant at the position in the length direction of the photosensitive drum, whereas the exposure optical system is closed in the closed casing. It can be seen that the illuminance on the surface of the photoconductor drum is constant at the position in the length direction of the photoconductor drum in the copier incorporated therein. That is, in the copying machine of the above embodiment, the change in illuminance with respect to the change in external temperature is small.

In the first optical system traveling body 20, two fluorescent lamps are provided. However, only one fluorescent lamp may be provided, or three or more fluorescent lamps may be provided.

FIGS. 12 and 13 show the sealed casing 1.
0 shows a modified example. In FIG. 12, the case main body is the same as that shown in FIG. 2, so that its illustration is omitted. 12, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

This sealed casing is attached to a case composed of a case main body having the same structure as the case main body 51 of FIG. 2 and a lid 52A having the exposure window 3 so as to close the exposure window 3. And a rectangular frame-shaped sealing member 13A interposed between the contact glass 12 and the case and the peripheral edge of the lower surface of the contact glass 12.

On the upper surface of the front frame portion of the rectangular frame portion around the exposure window 3 in the lid 52A, the mounting height position of the contact glass 12 is defined at a position from the center portion and both ends. A positioning projection 71 is formed. These projections 71 are formed at the front end of the upper surface of the front frame portion. Positioning projections 71 are also formed on the upper surface of the rear frame portion of the rectangular frame-shaped portion of the lid body 52A, at the center of the length and at positions from both ends. These rectangular projections 71
Is formed from the rear end of the upper surface of the rear frame portion. A rubber plate 72 made of hard rubber is attached to the upper surface of each projection 71. Each projection 71 and a rubber plate 72 fixed thereon constitute a height positioning portion.

A rectangular frame-shaped sealing member 13A is mounted on the upper surface of the rectangular frame-shaped portion of the lid 52A. At this time, the front frame portion of the seal member 13A is placed on the inside (rear side) of the protrusion 71 on the front frame portion upper surface of the lid 52A, and the rear frame portion of the seal member 13A is positioned on the rear frame upper surface of the lid 52A. Is placed on the inside (front side) of the projection 71 in the above.

The contact glass 12 is placed on the seal member 13A and the rubber plate 72. Then, with a fixture not shown, as shown in FIG.
The contact glass 12 is attached to the lid 52A in a state where the seal member 13A is pressed by the contact glass 12 and the contact glass 12 is supported on the projection 71 via the rubber plate 72. The lid 52A is fixed to the case body in the same manner as in FIG.

In the above example, the rubber plate 72 is attached to the projection 71, but the rubber plate 72 may not be provided.

FIG. 14 and FIG.
0 shows another modified example. This sealed casing
It is the same as that shown in FIG. 12 except that the position of the positioning projection on the lid and the size of the seal member are different. 14, the same parts as those in FIG. 12 are denoted by the same reference numerals, and the description thereof will be omitted.

Each positioning rectangular projection 81 formed on the upper surface of the front frame portion of the rectangular frame portion around the exposure window 3 in the lid 52B is formed from the rear end of the upper surface of the front frame portion.
Each positioning projection 81 formed on the upper surface of the rear frame portion of the rectangular frame portion of the lid 52B is formed from the front end of the upper surface of the rear frame portion. A rubber plate 82 is attached to the upper surface of each projection 81.

A rectangular frame-shaped sealing member 13B is mounted on the upper surface of the rectangular frame-shaped portion of the lid 52B. At this time, the front frame portion of the seal member 13B is placed on the outside (front side) of the projection 81 on the front frame portion upper surface of the lid 52B, and the rear frame portion of the seal member 13B is positioned on the rear frame upper surface of the lid 52B. It is placed on the outside (rear side) of the projection 81.

The contact glass 12 is placed on the seal member 13B and the rubber plate 82. Then, as shown in FIG. 15, the sealing member 13 </ b> B is pressed by the contact glass 12 by the fixture (not shown), and the contact glass 12 is supported by the protrusion 81 via the rubber plate 82.
Is attached to the lid 52B.

In the above example, the rubber plate 82 is attached to the projection 81, but the rubber plate 82 may not be provided.

FIG. 16 and FIG.
0 shows another modified example. This sealed casing
It is the same as that shown in FIG. 12 except that the configuration of the positioning projection and the sealing member on the lid is different and that the rubber plate is not provided on the positioning projection. FIG.
6, the same components as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted.

Each positioning projection 91 formed on the upper surface of the front frame portion of the rectangular frame portion around the exposure window 3 in the lid 52C has a length from the front edge to the rear edge of the upper surface of the front frame portion. doing. Similarly, each positioning projection 91 formed on the upper surface of the rear frame portion of the rectangular frame portion of the lid 52C has a length from the front edge to the rear edge of the upper surface of the rear frame portion.

The seal member 13C has six seal member structures 101 to 1 in accordance with the shapes of the portions between the adjacent positioning projections 91 on the upper surface of the rectangular frame-shaped portion of the lid 52C.
06.

Each of the sealing member structures 101 to 106 is fitted into a corresponding one of the adjacent positioning projections 91 on the upper surface of the rectangular frame-shaped portion of the lid 52C. Further, the contact glass 12 is placed on the seal member structures 101 to 106 and the positioning projections 91 and 92. Then, as shown in FIG. 17, the contact glass 12 is attached to the lid 52C in a state where the seal member 13C is pressed by the contact glass 12 and the contact glass 12 is supported by the projection 91, as shown in FIG. I have.

FIGS. 18, 19 and 20 show another modified example of the sealed casing 10. FIG. This sealed casing is the same as that shown in FIG. 12 except that the configuration of the positioning projection and the sealing member on the lid is different and that no thin plate is provided on the positioning projection. In FIG. 18, the same portions as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted.

Each positioning rectangular projection 111 formed on the upper surface of the front frame portion of the rectangular frame portion around the exposure window 3 in the lid 52D has a length from the front edge to the rear edge of the upper surface of the front frame portion. Have. Similarly, each positioning protrusion 111 formed on the upper surface of the rear frame portion of the rectangular frame portion of the lid 52D has a length from the front edge to the rear edge of the upper surface of the rear frame portion.

The seal member 13D has a rectangular frame shape similar to the rectangular frame portion of the lid 52D. And the sealing member 1
On the lower surface of the 3D, a groove-shaped notch 112 into which the positioning projection 111 is fitted is formed in a portion corresponding to each positioning projection 111. The width of each notch 112 is formed slightly smaller than the thickness of the positioning projection 111.

The seal member 13D is mounted on the upper surface of the rectangular frame-shaped portion of the lid 52D such that the positioning projections 111 corresponding to the respective notches 112 are fitted. E in this state
FIGS. 19A and 19B show the E-F cross section and the FF cross section. The contact glass 12 is placed on the seal member 13D. Then, the contact glass 12 is attached to the lid 52D in a state where the seal member 13D is pressed by the contact glass 12 and the projection 111 supports the contact glass 12 via the seal member 13D by a fixture (not shown). . The EE section and the FF section in this state are shown in FIGS.

As shown in FIG. 21, the positioning projections 121 are formed leaving the outer peripheral edges of the upper surfaces of the front frame portion and the rear frame portion of the rectangular frame portion of the lid 52E. A notch 122 into which the positioning protrusion 121 is fitted may be formed at a position corresponding to the positioning protrusion 121.

Further, as shown in FIG. 22, a rising wall 123 is formed on the outer peripheral side of the upper surface of the front frame portion and the rear frame portion of the rectangular frame portion of the lid 52F, and the positioning projection 131 is formed on the lid 52F. A notch 132 formed by leaving a portion from the rising wall 123 on the upper surface of the front frame portion and the rear frame portion of the rectangular frame portion, and fitting the positioning projection 131 at a position corresponding to the positioning projection 131 of the seal member 13F.
May be formed.

FIGS. 23, 24 and 25 show another modified example of the sealed casing 10. FIG. This sealed casing is the same as that shown in FIG. 12 except that the configurations of the lid and the seal member are different. In FIG. 23, the same components as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted.

A concave portion 151 is formed on the upper surface of the lid 52G, and an exposure window 3 is opened on the bottom surface of the concave portion 151. Therefore, the bottom of the recess 151 has a rectangular frame shape. The edges of the rectangular frame portion on the upper surface of the front frame portion and the rear frame portion on the side of the exposure window 3 are cut off, leaving a central portion of the length and both left and right end portions. This cut is indicated by reference numeral 152.
Exposure window 3 at the top of the front and rear frames of the rectangular frame
Rubber plates 153 are attached to the center of the length of the side edge and the left and right ends, respectively.

After the rectangular frame-shaped sealing member 13G is fitted and fixed in the concave portion 151 of the lid 52G, the contact glass 12 is fitted in the concave portion 151. Then, as shown in FIGS. 24 and 25, the sealing member 13G is
The contact glass 12 is attached to the lid 52G in a state where the contact glass 12 is supported by the rubber plate 153 on the rectangular frame portion of the lid 52G.

It should be noted that instead of the sealing member 13G,
As shown in FIG. 26, a seal member 52H having an L-shaped cross section in which a notch 161 into which the outer peripheral edge of the contact glass 12 fits is formed over the entire circumference may be used. Also, instead of the seal member 13G, as shown in FIG.
2 may be used. further,
Instead of the seal member 13G, as shown in FIG.
May be used.

As the material of the sealing members 13 and 13A to 13J used in the above-described embodiment or the modified example, a sponge material, a skin layer made of a resin layer of the same material around a sponge core body, may be used. Those formed, those made of rubber, those in which a resin sheet is attached around a sponge core, and the like can be used. Also, sealing member 1
As the third and 13A to 13F, those having a tongue-shaped protrusion formed on the surface receiving the contact glass 12 may be used.

FIG. 29 shows a modification of the case 11 of the above embodiment shown in FIG. In FIG. 29,
The same components as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In this case 200, the lid 202 is
, But the case body 201 is different from that of FIG. That is, the case main body 201 includes four side plates 211 to 214 and the bottom body 215. In addition, brackets 216 protruding inward are integrally formed at both ends of the left and right side plates 212 and 214. Each bracket 216 has a pair of upper and lower screw insertion holes 217.

Also, at the front and rear edges of the upper surface of the bottom body 215,
Two brackets 218 projecting upward are integrally formed. Each bracket 218 is also provided with a screw insertion hole 219.

At the left ends of the outer surfaces of the front plate 211 and the rear plate 213, cutouts are formed in which the brackets 216 of the left plate 212 are respectively fitted, so that the connecting portions 2 are formed.
20 are formed. In addition, a notch into which the bracket 216 of the right side plate 214 is fitted is formed at the right end of the outer surface of the front side plate 211 and the rear side plate 213, thereby forming a connecting portion 220. Each connecting part 22
0 has a pair of upper and lower screw holes 221.

At the lower ends of the outer surfaces of the front plate 211 and the rear plate 213, cutouts 222 are formed at positions corresponding to the brackets 218 of the bottom body 215, into which the brackets 216 are respectively fitted. A screw hole 223 is formed in a portion of the outer surface of the front plate 211 and the rear plate 213 where the notch 222 is formed at the lower end.

After the bracket 216 of the left side plate 212 is combined with the left end connecting portion 220 of the front side plate 211 and the rear side plate 213, the screw is screwed from the screw insertion hole 217 to the screw hole 221, so that the front side plate 211 and the rear side The left side plate 212 is connected to the side plate 213. Similarly, after the bracket 216 of the right side plate 214 is combined with the right end connecting portion 220 of the front side plate 211 and the rear side plate 213, the screw is screwed from the screw insertion hole 217 to the screw hole 221 so that the front side plate 211 and the rear Right side plate 2 on side plate 213
12 are connected.

Further, the notches 222 of the front plate 211 and the rear plate 213 correspond to the brackets 216 of the bottom body 215.
After being inserted, the screw holes 219 to the screw holes 223 are inserted.
The bottom body 215 is connected to the front side plate 211 and the rear side plate 213 by screwing the screws.

The lid 202 is fixed to the case body 201 assembled in this manner in the same manner as described with reference to FIG.

FIG. 30 shows a modification of the case 11 shown in FIG. 2 of the above embodiment. Although the case of FIG. 2 was composed of a case body and a lid having an upper surface opened, the case 300 of FIG. 30 has a bottom body 301 and a case body 302 having an exposure window 3 formed on the upper surface and having a lower surface opened. It is composed of Then, the bottom body 301 is fixed to the case main body 302 by a method similar to the method described with reference to FIG.

FIG. 31 and FIG. 32 are diagrams of FIG.
Of the case 11 shown in FIG. These cases are used particularly when the lens unit 40 that is built in the lens unit case 600 is used. The left end surface of the lens unit case 600 is provided with a light input slit (not shown) for introducing light from the second optical system traveling body 30. A light output slit (not shown) for guiding the light reflected by the sixth mirror 44 (see FIG. 1) to the photosensitive drum 1 is formed on the lower surface of the lens unit case 600. The light output slit is closed by a glass plate (not shown).

The case 400 of FIG. 31 comprises a bottom body 401 and a case body 402 having an exposure window 3 formed on the upper surface and an open lower surface, as in the case of FIG. A rectangular hole 403 smaller than the bottom surface of the lens unit case 600 is formed in the bottom body 401. And
The lens unit case 600 is placed and fixed on the bottom body 401 so as to close the hole 403. Bottom 401
Is fixed to the case main body 402 in the same manner as the method described with reference to FIG.

The case 500 shown in FIG. 32 comprises a bottom body 501 and a case body 502 having an exposure window 3 formed on the upper surface and an open lower surface as in the case of FIG. At the lower end of the outer surface of the front and rear side walls of the case body 502, a notch 503 is formed over the entire length. A pair of left and right screw holes 504 are formed in the front and rear side walls of the case body 502 where the cutouts 503 are formed.

At the front and rear edges of the bottom body 501, rising walls 505 are integrally formed. A screw insertion hole 506 is formed in each rising wall 505 at a position corresponding to the screw hole 504 of the case main body 502. Further, a rectangular hole 507 smaller than the bottom surface of the lens unit case 600 is formed in the bottom body 501. And the bottom body 5
01, the lens unit case 600 is placed and fixed so as to close the hole 507.

The bottom 5 is inserted into the notch 503 of the case body 502.
After the rising wall 505 of FIG. 01 is fitted, a screw is screwed from the screw insertion hole 506 to the screw hole 504, whereby the bottom body 501 is connected to the case body 502.

[0082]

According to the present invention, it is possible to prevent outside air from entering between the frame member and the contact glass. Therefore, it is possible to prevent image deterioration and increase in toner consumption.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing the overall configuration of an electrophotographic copying machine.

FIG. 2 is an exploded perspective view showing a sealed casing in which an optical system for exposure is built.

FIG. 3 is a cross-sectional view showing a configuration of a first optical system traveling body.

FIG. 4 is a plan view showing a slit plate.

FIG. 5 is a graph showing an illuminance characteristic on a document surface with respect to a position in a length direction of a fluorescent lamp.

FIG. 6 is a graph showing the illuminance characteristics on the photosensitive drum surface with respect to the length direction position of the fluorescent lamp when a slit plate having a slit having a uniform width in the length direction is used.

7 is a graph showing the illuminance characteristics on the surface of the photosensitive drum with respect to the position in the length direction of the fluorescent lamp when the slit plate of FIG. 4 is used.

FIG. 8 is a graph showing an illuminance characteristic on a document surface with respect to a temperature of a fluorescent lamp.

FIG. 9 is a graph showing a photosensitive drum surface potential characteristic with respect to a temperature of a fluorescent lamp when a white original is exposed.

FIG. 10 is a graph showing a photosensitive drum surface potential characteristic with respect to a temperature of a fluorescent lamp when a gray document is exposed.

FIG. 11 is a graph for comparing the characteristics with respect to the external temperature change of a copying machine in which the exposure optical system is built in the closed casing 10 and a copying machine in which the exposure optical system is not built in the closed casing. is there.

FIG. 12 is an exploded perspective view showing a modified example of the sealed casing.

13 is an enlarged sectional view taken along line AA of FIG.

FIG. 14 is an exploded perspective view showing another modified example of the sealed casing.

FIG. 15 is an enlarged sectional view taken along line BB of FIG. 14;

FIG. 16 is an exploded perspective view showing another modified example of the sealed casing.

17 is a cross-sectional view showing a cross section taken along line CC of FIG. 16 and an enlarged cross section taken along line DD of FIG. 16;

FIG. 18 is an exploded perspective view showing another modified example of the sealed casing.

FIG. 19 is an enlarged cross-sectional view showing a cross section taken along line EE and a cross section taken along line FF of FIG. 18 before the contact glass is fixed.

20 is an enlarged cross-sectional view showing a cross section taken along line EE and a cross section taken along line FF of FIG. 18 after the contact glass is fixed.

21 is a cross-sectional view showing a modification of the lid and the seal member in the sealed casing of FIG.

FIG. 22 is a sectional view showing another modification of the lid and the seal member in the sealed casing of FIG. 18;

FIG. 23 is an exploded perspective view showing another modified example of the sealed casing.

24 is an enlarged sectional view taken along line GG of FIG.

FIG. 25 is an enlarged sectional view taken along line HH of FIG.
FIG. 3 is an exploded perspective view showing a sealed casing in which an exposure optical system is built.

FIG. 26 is a sectional view showing a modified example of the seal member in the sealed casing of FIG. 23;

FIG. 27 is a sectional view showing another modified example of the seal member in the sealed casing of FIG. 23;

FIG. 28 is a sectional view showing another modified example of the seal member in the sealed casing of FIG. 23;

FIG. 29 is an exploded perspective view showing a modification of the case of FIG. 2;

FIG. 30 is an exploded perspective view showing another modification of the case of FIG. 2;

FIG. 31 is an exploded perspective view showing another modified example of the case of FIG. 2;

FIG. 32 is an exploded perspective view showing another modification of the case of FIG. 2;

FIG. 33 is a partially cutaway perspective view showing a structure for attaching a contact glass to a frame in a conventional copying machine.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Glass plate 3 Exposure window 10 Sealing casing 11 Case 12 Contact glass 13, 13A-13G Seal member 20 First optical system traveling body 21, 22 Fluorescent lamp 30 Second optical system traveling body 40 Lens unit 51 Case Main body 52, 52A to 52G Lid body 71, 81, 91, 111, 121, 131 Positioning projection 201 Case main body 301, 401, 501 Bottom body 302, 402, 502 Case main body

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shuichi Ikuno 1-2-2, Tamazuki, Chuo-ku, Osaka-shi, Osaka Inside Mita Kogyo Co., Ltd. (72) Inventor Shigeo Koyama 1-2-2, Tamazuki, Chuo-ku, Osaka, Osaka No. 28 Inside Mita Kogyo Co., Ltd. (56) References JP-A-4-368928 (JP, A) JP-A-2-108033 (JP, A) JP-A 1-90036 (JP, U) JP-A-54 103840 (JP, U) Actual opening 60-60440 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/04-15/04 120 G03B 27/62-27/64 G03G 21/00 530-540 G03G 21/20

Claims (4)

(57) [Claims] A contact glass on which an original is placed;
In an image forming apparatus in which a seal member is interposed between a frame member to which a contact glass is attached, a plurality of upwardly projecting height positioning portions are formed on an upper surface of the frame member, and the seal member is positioned at a height. The contact glass is mounted on the frame member while being placed on the top surface of the frame member so as to pass through the outside or inside of the portion, and the contact glass is pressed against the seal member and received by the height positioning portion. An image forming apparatus. 2. A contact glass on which a document is placed,
In an image forming apparatus in which a seal member is interposed between a frame member to which a contact glass is mounted, a plurality of upwardly projecting height positioning portions are formed on the upper surface of the frame member, and each of the height members is formed on the seal member. A notch portion in which the height positioning portion fits is formed at a position corresponding to the positioning portion, and the height positioning portion is fitted in the notch portion of the seal member, and the seal member is provided on the upper surface of the frame member. An image forming apparatus, wherein the contact glass is mounted on the frame member in a state where the contact glass is pressed against the seal member. 3. The image forming apparatus according to claim 1, wherein the seal member is endless. 4. A contact glass on which a document is placed,
In an image forming apparatus in which a seal member is interposed between a frame member to which a contact glass is attached, a plurality of upwardly projecting height positioning portions are formed on an upper surface of the frame member, and the seal member is a frame member. It is composed of a plurality of seal member structures corresponding to portions between adjacent height positioning portions on the upper surface, and each seal member structure corresponds to a corresponding one of the portions between adjacent height positioning portions on the frame member upper surface. An image forming apparatus, wherein the contact glass is attached to the frame member in a state where the contact glass is pressed into contact with the seal member and received by the height positioning portion.