JPH07287319A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce influence caused by the change of external environment on an exposing optical system and to prevent dust or the like from entering the exposing optical system from outside by using a fluorescent lamp as an exposure lamp and arranging the exposing optical system in the inside of a sealing casing. CONSTITUTION:The exposing optical system is incorporated in the sealing casing 10 which consists of a case 11 having an exposing window at an upper surface and a contact glass 12 attached at the case 11 so as to hermetically seal the exposing window. Also, the exposing optical system is constituted of first and second optical system traveling bodies 20 and 30 and a lens unit 40. Moreover, the first optical system traveling body 20 is provided with a pair of the exposure lamps 21 and 22 exposing and scanning the image of the original placed on the contact glass 12 and a first mirror 23 reflecting the reflected light from the original. Then, a hot cathode type fluorescent lamp is for example used as the exposure lamps 21 and 22. The other type of phosphor such as cold cathode type or the like can be used as the exposure lamps 21 and 22.

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 When a copying machine is installed in a so-called convenience store, dustproof measures for the copying machine are extremely important. Because the convenience store is located in a place satisfying the location conditions with excellent traffic conditions, it faces the general road, and the copying machine is generally installed near its entrance.
This is because they are often exposed to dust and sunlight.

Conventionally, dust-proof measures have been taken in the exposure optical system of a copying machine. That is, in the copying machine, in order to perform the powder development, it is necessary to protect the exposure optical system against toner scattering. Therefore, the exposure optical system is generally protected against toner scattering by separating the developing unit and the exposure optical system.

[0004]

On the other hand, in order to reduce the influence on the exposure optical system due to changes in the external environment and prevent dust and the like from entering the exposure optical system from the outside,
It is conceivable to confine the exposure optical system in a sealed space. However, since a halogen lamp that generates a large amount of heat is generally used as an exposure light source for a copying machine, and it is necessary to cool the exposure optical system, it is difficult to make the exposure optical system a closed structure. there were.

According to the present invention, the exposure optical system can be confined in a hermetically sealed space, the influence of the external environment change on the exposure optical system can be reduced, and dust and the like can be prevented from entering the exposure optical system from the outside. It is an object of the present invention to provide an image forming apparatus capable of performing the above.

[0006]

A first image forming apparatus according to the present invention uses a fluorescent lamp as an exposure lamp in an image forming apparatus in which an original image is exposed by moving an exposure lamp. An exposure optical system including an exposure lamp is arranged in a hermetically sealed casing.

A second image forming apparatus according to the present invention uses a fluorescent lamp as an exposure lamp in an image forming apparatus in which a document image is exposed by moving an exposure lamp. The optical system is arranged in a hermetic casing, and the hermetic casing comprises a case having an exposure window and a contact glass attached to the case so as to close the exposure window, and a peripheral portion of the exposure window in the case. The seal member is interposed between the contact glass and the contact glass.

A third image forming apparatus according to the present invention uses a fluorescent lamp as an exposure lamp in an image forming apparatus in which an original image is exposed by moving the exposure lamp. An optical system is arranged in a hermetic casing, and the hermetic casing is composed of a case having an exposure window and a contact glass attached to the case so as to close the exposure window, and the case is a case body with an open top surface. And a lid body fixed to the case body and having an exposure window, and a seal member is interposed between a peripheral portion of the exposure window of the lid body and the contact glass.

In a fourth image forming apparatus according to the present invention, a fluorescent lamp is used as the exposure lamp in the image forming apparatus in which the original image is exposed by moving the exposure lamp. The optical system is arranged in a sealed casing, and the sealed casing includes a case having an exposure window and a contact glass attached to the case so as to close the exposure window, and the case has an exposure window on the upper surface. And a bottom body fixed to the case body, wherein a seal member is interposed between a peripheral portion of the exposure window of the case body and the contact glass. To do.

In the second, third and fourth image forming apparatuses described above, the contact glass mounting structure to the case may be, for example, the following (1) to (3).

(1) A plurality of upwardly projecting height positioning portions are formed in the peripheral portion of the exposure window in the case, and a seal member is provided on the peripheral portion of the exposure window in the case as the height positioning portion. The contact glass is mounted so as to pass through the outside or the inside, and the contact glass is attached to the case in a state in which the contact glass is in pressure contact with the seal member and is received by the height positioning portion.

(2) A plurality of upwardly projecting height positioning portions are formed in the peripheral portion of the exposure window in the case, and the sealing member has height positioning portions at positions corresponding to the respective height positioning portions. A notch part to be fitted is formed, and the height positioning part is fitted into the notch part of the seal member, and the seal member is placed around the exposure window in the case. The contact glass is attached to the case while being pressed against the seal member.

(3) A plurality of upwardly projecting height positioning portions are formed in the peripheral portion of the exposure window in the case, and the sealing member is provided with adjacent height positioning portions in the peripheral portion of the exposure window in the case. It is composed of a plurality of seal member structure corresponding to the inter-portion, each seal member configuration in the corresponding portion of the portion between the adjacent height positioning portion on the peripheral portion of the exposure window in the case The contact glasses are attached to the case in a state in which they are fitted in each other, and the contact glasses are pressed against the seal member and received by the height positioning portion.

[0014]

In the first, second, third or fourth image forming apparatus according to the present invention, since the exposure optical system including the exposure lamp is arranged in the hermetically sealed casing, the exposure optical system is kept at the outside temperature. , Less susceptible to humidity and external dust.

In the second, third or fourth image forming apparatus according to the present invention, since the sealing property between the case and the contact glass is improved, it is possible to prevent dust from entering between the case and the contact glass. It can be surely prevented, and the sealing property of the case is enhanced.

[0016]

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

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

The copying machine includes a copying machine main body, an exposure optical system section provided in an upper part of the copying machine main body, a developing section and a recording paper conveying mechanism provided below the exposure optical system section in the copying machine main body. It is composed of parts.

The developing section includes a photosensitive drum 1.
Although not shown around the photoconductor drum 1, a charger that charges the photosensitive layer on the surface of the photoconductor drum 1 and visualizes the electrostatic latent image formed on the photoconductive layer as a toner image. Developing device, transfer discharger for transferring the toner image formed on the photosensitive layer to the recording paper, separation discharger for separating the recording paper from the photosensitive drum 1, surface of the photosensitive drum 1 after transfer A cleaning device and the like for removing the residual toner is disposed.

The exposure optical system section is built in the sealed casing 10. The sealed casing 10 includes a case 11 having an exposure window on its 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 is the 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 has a pair of exposure lamps 21 and 22 for exposing and scanning an image of an original document placed on the contact glass 12, and a first mirror 23 for reflecting light reflected from the original document. Is equipped with.

The second optical system traveling body 30 has 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 are provided.

The lens unit 40 has a lens 41 on which the light reflected by the third mirror 32 of the second optical system traveling body 30 is incident, and a first for guiding the light emitted from the lens 41 to the surface of the photosensitive drum 1. 4, fifth and sixth mirror 4
2, 43, 44 are provided. By irradiating the photoconductor drum 1 with the light emitted from the lens unit 40, an electrostatic latent image is formed on the photoconductive layer on the surface of the photoconductor 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 ½ of the speed of the first optical system traveling body 20 and a distance that is ½ of the moving distance of the first optical system traveling body 20. The description of the recording paper transport mechanism is omitted.

FIG. 2 shows a hermetically sealed casing 10 in which an exposure optical system section is incorporated.

The hermetic casing 10 has an exposure window 3 on the upper surface.
From the case 11 having a contact glass 12 attached to the case 11 so as to close the exposure window 3 and the rectangular frame-shaped seal member 13 interposed between the case 11 and the peripheral portion of the lower surface of the contact glass 12. It is configured.

The case 11 comprises a case body 51 in the shape of a rectangular parallelepiped whose top surface is open, and a lid 52 having the exposure window 3. On the bottom surface of the case body 51, the lens unit 40
A slit 54 is formed to guide light from the photosensitive drum 1 to the photosensitive drum 1. The slit 54 is sealed by the glass plate 2 (see FIG. 1). Two notches 55 are formed in the upper end of the outer surface of both front and rear walls of the case body 51. A screw hole 56 is formed in each of the front and rear walls of the case body 51 where the notches 55 are formed.

Two positioning protrusions 57 are formed on the upper end surfaces of both front and rear walls of the case body 51. Further, in this example, guide rails 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 are attached to the inner surfaces of the front and rear side walls of the case body 51. Has 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 body 51, a connector 60 for connecting an electric cord extending from a device inside the exposure optical system section to an electric cord 59 outside the case body 51 is attached. The connector 53 attached to the external electric cord 59 is provided with a sealing mechanism for preventing the connector 60 from impairing the hermeticity of the case body 51.

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

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

The lid 52 has a protrusion 61 on the case body 5.
The notch 55 and the notch 63 are fitted in the protrusions 57 of the case body 51, respectively.
After being placed on the case 1, the screws (not shown) are screwed into the screw holes 56 of the case body 51 from the screw insertion holes 62 of the respective protrusions 61, whereby the case body 51 is fixed.

The case body 51 and 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 the detailed construction 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.
Is equipped with. As the exposure lamps 21 and 22, here, a hot cathode type fluorescent lamp is used. As the exposure lamps 21 and 22, other types of fluorescent lamps such as a cold cathode type may be used.

In a part of the circumference of each fluorescent lamp 21, 22,
Sheet heating elements 26, 27 extending in the length direction are attached. Further, the fluorescent lamp 2 is attached to the first optical system traveling body 20.
A temperature sensor 28 for detecting the ambient temperature of Nos. 1 and 22 is provided. Further, a light amount sensor 29 for detecting the light amount of the light reflected from the document is provided.

The light emitted from both fluorescent lamps 21 and 22 is
It is reflected by the original document on the contact glass 12. The reflected light passes through the slit 25 and is incident on the first mirror 23. The light incident on 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 positions of the fluorescent lamps 21 and 22 in the longitudinal direction. Further, FIG. 6 shows the illuminance characteristics on the surface of the photoconductor drum 1 with respect to the positions of the fluorescent lamps 21 and 22 in the length direction when a slit plate having slits having a uniform width over the length direction is used. The illuminance on the document surface with respect to the positions of the fluorescent lamps 21 and 22 in the lengthwise direction is substantially constant except for both ends as shown in FIG. However, the illuminance on the surface of the photosensitive drum 1 after passing through the lens 41 becomes lower toward both ends in the length direction of the fluorescent lamps 21 and 22 depending on the characteristics of the lens 41, as shown in FIG. .

Therefore, 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 provided.
As shown in FIG. 4, the width of the central part 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 photoconductor drum 1 with respect to the longitudinal positions of the fluorescent lamps 21 and 22 after the illuminance is 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 original 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 a gray original is exposed.
Shows the relationship with the surface potential of.

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

Therefore, in this embodiment, each fluorescent lamp 21,
By driving and controlling the sheet heating elements 26 and 27 attached to 22 on the basis of the temperature detected by the temperature sensor 28, the temperature of each fluorescent lamp 21 and 22 is kept constant.

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

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

In FIG. 11, a copying machine in which the exposure optical system section is built in the closed casing 10 and a copying machine in which the exposure optical system section is not built in the closed casing are installed near an air conditioner. Then, the illuminance on the surface of the photoconductor drum with respect to the longitudinal position 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 copying machine in which the exposure optical system section is built in the closed casing 10, and FIG. 11B shows the exposure optical system section built in the closed casing. It shows the characteristics for not copying machines. From this figure, in a copying machine in which the exposure optical system section is not built in the hermetic casing, the illuminance on the surface of the photoconductor drum is not constant in the longitudinal position of the photoconductor drum, whereas the exposure optical system section is the hermetic casing. It can be seen that in the copier built in, the illuminance on the surface of the photoconductor drum is constant at the position in the lengthwise direction of the photoconductor drum. That is, in the copying machine of the above embodiment, the change in illuminance with respect to the change in external temperature is small.

Although two fluorescent lamps are provided in the first optical system traveling body 20 described above, only one fluorescent lamp may be provided, or three or more fluorescent lamps may be provided.

12 and 13 show a hermetically sealed casing 1
The modification of 0 is shown. In FIG. 12, the case main body is the same as that shown in FIG. 2, and therefore its illustration is omitted. 12, the same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

The hermetically sealed casing is made up of a case body having the same structure as the case body 51 of FIG. 2 and a lid 52A having the exposure window 3, and is attached to the case so as to close the exposure window 3. The contact glass 12 and a seal member 13A having a rectangular frame shape interposed between the case and the peripheral portion of the lower surface of the contact glass 12.

On the upper surface of the front frame portion of the rectangular frame-shaped portion around the exposure window 3 in the lid 52A, the mounting height position of the contact glass 12 is defined at the position from the center of the length and both ends. Positioning protrusions 71 are formed. These protrusions 71 are formed from the front end of the upper surface of the front frame portion. Positioning protrusions 71 are also formed on the upper surface of the rear frame portion of the rectangular frame-shaped portion of the lid 52A at the center of the length and at positions from both ends. These rectangular protrusions 71
Are 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 protrusion 71. Each protrusion 71 and the rubber plate 72 fixed on it form a height positioning portion.

A rectangular frame-shaped seal member 13A is placed 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 inner side (rear side) of the projection 71 on the upper surface of the front frame portion of the lid body 52A, and the rear frame portion of the seal member 13A is the upper surface of the rear frame portion of the lid body 52A. It is placed on the inner side (front side) of the protrusion 71.

The contact glass 12 is placed on the seal member 13A and the rubber plate 72. Then, as shown in FIG. 13, with a fixing tool (not shown),
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 by the protrusion 71 via the rubber plate 72. The lid 52A is fixed to the case body by the same method as in FIG.

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

14 and 15 show the sealed casing 1
The other modification of 0 is shown. This sealed casing is
It is the same as that shown in FIG. 12 except that the position of the positioning protrusion on the lid and the size of the seal member are different. 14, the same parts as those in FIG. 12 are designated by the same reference numerals and the description thereof will be omitted.

The positioning rectangular protrusions 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 are 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-shaped 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 protrusion 81.

A rectangular frame-shaped seal member 13B is placed 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 outer side (front side) of the protrusion 81 on the upper surface of the front frame portion of the lid body 52B, and the rear frame portion of the seal member 13B is placed on the upper surface of the rear frame portion of the lid body 52B. It is placed on the outer side (rear side) of the protrusion 81.

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

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

16 and 17 show the sealed casing 1
The other modification of 0 is shown. This sealed casing is
12 is the same as that shown in FIG. 12 except that the positioning protrusion and the seal member of the lid are different in structure and that the rubber plate is not provided on the positioning protrusion. Figure 1
6, the same components as those in FIG. 12 are designated by the same reference numerals, and the description thereof will be omitted.

Each positioning projection 91 formed on the upper surface of the front frame portion of the rectangular frame-shaped 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. is doing. Similarly, each positioning projection 91 formed on the upper surface of the rear frame portion of the rectangular frame-shaped 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 constituent members 101 to 1 according to 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.
It is composed of 06.

Each of the seal member structures 101 to 106 is fitted in a corresponding space between adjacent positioning projections 91 on the upper surface of the rectangular frame portion of the lid 52C. Further, the contact glass 12 is placed on the seal member structures 101 to 106 and the positioning protrusions 91 and 92. Then, as shown in FIG. 17, the contact glass 12 is attached to the lid 52C by a fixture (not shown) while the seal member 13C is pressed by the contact glass 12 and the contact glass 12 is supported by the protrusions 91. There is.

18, 19 and 20 show another modification of the hermetically sealed casing 10. This hermetically sealed casing is the same as that shown in FIG. 12 except that the positioning projection and the seal member of the lid body are different in structure and that a thin plate is not provided on the positioning projection. 18, parts that are the same as those in FIG. 12 are given the same reference numerals, and descriptions thereof will be omitted.

The positioning rectangular protrusions 111 formed on the upper surface of the front frame portion of the rectangular frame-shaped portion around the exposure window 3 in the lid 52D have 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-shaped 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 seal member 1
On the lower surface of 3D, a groove-shaped notch 112 into which the positioning protrusion 111 is fitted is formed in a portion corresponding to each positioning protrusion 111. The width of each notch 112 is formed to be slightly smaller than the thickness of the positioning protrusion 111.

The seal member 13D is placed on the upper surface of the rectangular frame-shaped portion of the lid 52D so that the positioning projections 111 corresponding to the respective notches 112 are fitted. E in this state
The −E cross section and the FF cross section are shown in FIGS. Further, the contact glass 12 is placed on the seal member 13D. The contact glass 12 is attached to the lid 52D in a state in which the seal member 13D is pressed by the contact glass 12 and is supported by the protrusion 111 via the seal member 13D by a fixture (not shown). . The EE cross section and the FF cross section in this state are shown in FIGS.

As shown in FIG. 21, the positioning projection 121 is formed by leaving the outer peripheral edges of the upper surface of the front frame portion and the rear frame portion of the rectangular frame-shaped portion of the lid 52E, and the sealing member 13E. You may make it form the notch 122 which fits the positioning protrusion 121 in the position corresponding to the positioning protrusion 121.

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

23, 24 and 25 show another modification of the hermetically sealed casing 10. This sealed casing is the same as that shown in FIG. 12 except that the configurations of the lid and the sealing member are different. In FIG. 23, the same parts as those in FIG. 12 are designated by the same reference numerals, and the description thereof will be omitted.

A recess 151 is formed on the upper surface of the lid 52G, and the exposure window 3 is opened on the bottom of the recess 151. Therefore, the bottom surface of the recess 151 has a rectangular frame shape. The edge portions of the upper surfaces of the front frame portion and the rear frame portion of the rectangular frame-shaped portion on the side of the exposure window 3 are cut off leaving the central portion of the length and the left and right end portions. This cutout portion is indicated by reference numeral 152.
Exposure window 3 on the upper surface of the front frame portion and the rear frame portion of the rectangular frame portion
A rubber plate 153 is attached to each of the central portion and the left and right end portions of the side edge portion.

After the rectangular frame-shaped seal member 13G is fitted and fixed in the recess 151 of the lid 52G, the contact glass 12 is fitted in the recess 151. Then, as shown in FIG. 24 and FIG. 25, the seal member 13G causes the contact glass 12 to contact the contact glass 12 by a fixture not shown.
The contact glass 12 is attached to the lid 52G in a state in which the contact glass 12 is pressed by the rubber plate 153 on the rectangular frame portion of the lid 52G and is supported by the rubber plate 153.

Instead of the seal 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 portion of the contact glass 12 fits is formed may be used. Further, instead of the seal member 13G, as shown in FIG. 27, an inclined surface 16 whose width increases toward the inner peripheral surface upwards.
A seal member 13I having 2 may be used. further,
Instead of the seal member 13G, as shown in FIG. 28, an inwardly projecting glass pressing portion 162 is provided at the upper end of the inner peripheral surface.
You may use the sealing member 13J with which was formed.

As the material of the seal members 13 and 13A to 13J used in the above-mentioned embodiments or modifications, a sponge-made material and a skin layer made of a resin layer of the same material around a sponge-made core body are used. A formed product, a rubber product, or a sponge-made core body to which a resin sheet is attached can be used. In addition, the seal member 1
As 3, 13A to 13F, those having a tongue-shaped projection formed on the surface receiving the contact glass 12 may be used.

FIG. 29 shows a modification of the case 11 shown in FIG. 2 of the above embodiment. In FIG. 29,
2 that are the same as those in FIG.

In this case 200, the lid 202 is shown in FIG.
The case main body 201 is different from that of FIG. That is, the case main body 201 includes four side plates 211 to 214 and a bottom body 215. 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.

Further, at the front and rear edges of the upper surface of the bottom body 215,
Two brackets 218 protruding upward are integrally formed. Each bracket 218 also has a screw insertion hole 219.

At the left end portions of the outer surfaces of the front side plate 211 and the rear side plate 213, notches into which the brackets 216 of the left side plate 212 are respectively fitted are formed so that the connecting portion 2 is formed.
20 are formed. Further, a connecting portion 220 is formed by forming notches into which the brackets 216 of the right side plate 214 are respectively fitted at the right end portions of the outer surfaces of the front side plate 211 and the rear side plate 213. Each connecting portion 22
At 0, a pair of upper and lower screw holes 221 are formed.

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

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, a screw is tightened from the screw insertion hole 217 to the screw hole 221, so that the front side plate 211 and the rear side plate 211 are connected. 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 portions 220 of the front side plate 211 and the rear side plate 213, the front side plate 211 and the rear side plate 211 and the rear side plate 213 are tightened with screws from the screw insertion holes 217. Right side plate 2 on side plate 213
12 are connected.

Further, the notch 222 of the front side plate 211 and the rear side plate 213 corresponds to the bracket 216 of the bottom body 215.
After the screws are fitted, the screw insertion holes 219 through the screw holes 223
The bottom body 215 is connected to the front side plate 211 and the rear side plate 213 by tightening the screws.

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

FIG. 30 shows a modification of the case 11 shown in FIG. 2 of the above embodiment. The case of FIG. 2 is composed of a case body having an open upper surface and a lid body, whereas 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 an open lower surface. It consists of Then, the bottom body 301 is fixed to the case body 302 by a method similar to the method described in FIG.

FIG. 31 and FIG. 32 are the same as FIG. 2 of the above embodiment.
The modifications 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. Further, on the lower surface of the lens unit case 600, 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. The light output slit is closed by a glass plate (not shown).

The case 400 of FIG. 31, like the case of FIG. 30, is composed of a bottom body 401 and a case body 402 in which the exposure window 3 is formed on the upper surface and the lower surface is opened. The bottom body 401 has a rectangular hole 403 smaller than the bottom surface of the lens unit case 600. 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 body 402 by a method similar to that described with reference to FIG.

As in the case of FIG. 30, the case 500 of FIG. 32 is composed of a bottom body 501 and a case body 502 having an exposure window 3 formed on the upper surface and an opened lower surface. A notch 503 is formed over the entire length at the outer lower ends of the front and rear side walls of the case body 502. A pair of left and right screw holes 504 are formed in the portion of the case body 502 where the notch 503 is formed in the front and rear side walls.

Standing walls 505 are integrally formed on the front and rear edges of the bottom body 501. A screw insertion hole 506 is formed in each rising wall 505 at a position corresponding to the screw hole 504 of the case body 502. 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 body 5 is provided in the notch portion 503 of the case body 502.
After the rising wall 505 of 01 is fitted, the bottom body 501 is connected to the case body 502 by screwing a screw from the screw insertion hole 506 to the screw hole 504.

[0088]

According to the present invention, the exposure optical system can be enclosed in the sealed space. Therefore, it is possible to reduce the influence on the exposure optical system due to the change in the external environment and prevent dust and the like from entering the exposure optical system from the outside.

[Brief description of drawings]

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

FIG. 2 is an exploded perspective view showing a hermetically sealed casing in which an exposure optical system unit is incorporated.

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 of a fluorescent lamp in a length direction.

FIG. 6 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 a slit plate having slits with 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 the illuminance characteristic on the original surface with respect to the temperature of the fluorescent lamp.

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

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

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

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

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

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

15 is an enlarged cross-sectional view taken along the line BB of FIG.

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 the line CC of FIG. 16 and an enlarged cross section taken along the line DD.

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

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.

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

22 is a cross-sectional view showing another modified example of the lid and the seal member in the sealed casing of FIG.

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

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

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

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

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

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

FIG. 29 is an exploded perspective view showing a modified example of the case of FIG.

FIG. 30 is an exploded perspective view showing another modified example of the case of FIG.

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

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

[Explanation of symbols]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhisa Edahiro 1-22-28 Tamazo, Chuo-ku, Osaka City, Osaka Prefecture Mita Kogyo Co., Ltd. (72) Shuichi Ikuno 1-2-chome, Chuzo-ku, Osaka City, Osaka Prefecture No. 28 Mita Industry Co., Ltd.

Claims (8)

[Claims] 1. An image forming apparatus in which a document image is exposed by moving an exposure lamp, a fluorescent lamp is used as the exposure lamp, and an exposure optical system including the exposure lamp is arranged in a hermetically sealed casing. An image forming apparatus characterized by the above. 2. An image forming apparatus in which a document image is exposed by moving an exposure lamp, a fluorescent lamp is used as the exposure lamp, and an exposure optical system including the exposure lamp is arranged in a sealed casing. The hermetically-sealed casing includes a case having an exposure window and a contact glass attached to the case so as to close the exposure window, and a sealing member is provided between the peripheral portion of the exposure window and the contact glass in the case. An image forming apparatus, characterized in that 3. An image forming apparatus in which an original image is exposed by moving an exposure lamp, a fluorescent lamp is used as the exposure lamp, and an exposure optical system including the exposure lamp is arranged in a sealed casing. The hermetically sealed casing includes a case having an exposure window and a contact glass attached to the case so as to close the exposure window. The case is fixed to the case main body and the exposure is fixed to the case main body. An image forming apparatus comprising: a lid having a window for use, wherein a seal member is interposed between a peripheral portion of the exposure window of the lid and the contact glass. 4. An image forming apparatus in which an original image is exposed by moving an exposure lamp, a fluorescent lamp is used as the exposure lamp, and an exposure optical system including the exposure lamp is arranged in a sealed casing. The hermetically sealed casing includes a case having an exposure window and a contact glass attached to the case so as to close the exposure window. The case has a case body having an exposure window on the upper surface and an opening on the lower surface. And a bottom body fixed to the case body, wherein a seal member is interposed between the contact glass and a peripheral portion of the exposure window in the case body. 5. A plurality of upwardly projecting height positioning portions are formed in a peripheral portion of the exposure window of the case, and a sealing member is provided outside the height positioning portion on the peripheral portion of the exposure window of the case. Alternatively, the contact glass is mounted so as to pass through the inside, and the contact glass is attached to the case in a state in which the contact glass is in pressure contact with the seal member and is received by the height positioning portion. The image forming apparatus according to any one of 2, 3, and 4. 6. A plurality of upwardly projecting height positioning portions are formed in a peripheral portion of the exposure window of the case, and the sealing member is fitted with the height positioning portions at positions corresponding to the respective height positioning portions. The cutout portion is formed so that the height positioning portion fits into the cutout portion of the seal member, and the seal member is placed around the exposure window in the case. The image forming apparatus according to claim 2, wherein the contact glass is attached to the case while being in pressure contact with the seal member. 7. The image forming apparatus according to claim 5, wherein the seal member is endless. 8. A plurality of upwardly projecting height positioning portions are formed in the peripheral portion of the exposure window of the case, and the sealing member is provided at adjacent height positioning portions of the peripheral portion of the exposure window of the case. The seal member structure is composed of a plurality of seal member structures corresponding to the space portions, and each seal member structure is formed on a corresponding portion of the space between adjacent height positioning portions on the peripheral portion of the exposure window in the case. The contact glass is fitted in the case, and the contact glass is attached to the case in a state in which the contact glass is in pressure contact with the seal member and is received by the height positioning portion. The image forming apparatus according to item 1.