JPH11109837A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fluctuation of the light quantity of an element caused by generated heat from a light emitting element and the positional deviation of the light emitting element caused by the thermal deformation of an exposing element by providing a supporting member which is a hollow member with a heat radiating member inside. SOLUTION: The supporting member 20 is arranged on the inside of a photoreceptor drum 10 so that its center axis is aligned with the center axis of the drum 10 in a state where it holds an exposure optical system 12 of every color provided with a fin F1 being the heat radiating member which is aligned with the optical system 12 inside the member 20. Therefore, image exposure is performed by the optical system 12 perpendicularly to the center shaft of the drum 10. The optical system 12 provided with the fin F1 is attached to the member 20 for which a pipe-like hollow member is used and housed inside the base substance of the drum 10. A lead wire WA from an LED of every color, which is led out from the base plate of the optical system 12 and connected to a connector C attached to the lower part of a metallic casing, is disposed inside the member 20 through an insertion hole H1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, etc., which forms an image by forming a charging means, an image exposing means and a developing means around an image forming body. Related to an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as one method of forming a multi-color image, a color image is formed by sequentially performing charging, image exposure and development for each color within one rotation of one image forming body. Image forming apparatuses are known.

[0003] However, the above-mentioned color image forming apparatus is capable of forming a high-speed image in a method of forming a multi-color image, but the charging means, the image exposing means and the developing means within one rotation of the photosensitive member. It is necessary to arrange a plurality of sets, and there is a risk that the image exposure means may be stained by toner leaking from the developing means adjacent thereto and impair the image quality. To avoid this, it is necessary to increase the distance between the image exposure means and the developing means. For this reason, there is a disadvantage that the diameter of the photoreceptor is inevitably increased and the size of the apparatus is increased. For the purpose of avoiding this drawback, the substrate of the photoreceptor is formed of a translucent material, and a plurality of image exposure means are accommodated therein, and an image is exposed to the photoreceptor layer formed on the outer periphery thereof through the substrate. For example, an apparatus of the type is proposed in Japanese Patent Application Laid-Open No. 5-307307.

[0004]

The image forming apparatus according to the above proposal requires a small image exposing means for accommodating a plurality of image exposing means therein, and a small exposing element is used for the image exposing means. Used. Therefore, an exposure element in which a plurality of LEDs (light-emitting diodes) are linearly arranged on a substrate is particularly often used as a light-emitting element.

However, when an image is formed, the heat generated by the LED as a light emitting element causes a problem in that the light quantity of the light emitting element fluctuates and the position of the light emitting element shifts due to thermal deformation of the exposure element, thereby causing an image defect.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which solves the above-mentioned problems and prevents a change in the amount of light of a heating element due to heat generated from the light emitting element and a displacement of the light emitting element due to thermal deformation of an exposure element. I do.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a rotating image forming body and an image exposing means in which a plurality of light emitting elements arranged in a line are provided on a metal casing. In the image forming apparatus to be provided, it is preferable that the image forming body and a supporting member for supporting the image exposing means are integrally provided, the supporting member is a hollow member, and a heat radiating member is provided inside. This is achieved by a characteristic image forming apparatus.

[0008]

Embodiments of the present invention will be described below. The description of the present application does not limit the technical scope of the claims and the meaning of terms. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope.

An image forming process and each mechanism of an embodiment of the image forming apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a color image forming apparatus showing an embodiment of the image forming apparatus according to the present invention, FIG. 2 is a view showing an image exposing means, and FIG. 3 is a perspective view of FIG. 4 is a diagram showing a heat radiating member provided in the image exposure unit. FIG. 5 is a sectional configuration diagram of the image forming unit. FIG. 6 is a diagram showing a flange member of FIG. .

Referring to FIGS. 1 to 5, a photosensitive drum 10 as a drum-shaped image forming member is, for example, a cylindrical light-transmitting resin substrate formed of a light-transmitting member made of a light-transmitting acrylic resin. Is provided inside, and a translucent conductive layer and an organic photoreceptor layer (OPC) are formed on the outer periphery of the substrate.
It is rotated in the direction shown by the arrow in FIG.

In the present embodiment, it is sufficient that the photoconductor layer of the photosensitive drum 10 has an exposure light amount capable of giving an appropriate contrast. Therefore, the light transmittance of the light-transmitting resin substrate of the photosensitive drum in the present embodiment does not need to be 100%, and may have a characteristic such that a certain amount of light is absorbed when the exposure beam is transmitted. . As a material of the light-transmitting substrate, an acrylic resin, particularly one obtained by polymerization using a methyl methacrylate monomer is preferably used because of its excellent light-transmitting properties, strength, accuracy, surface properties, and the like, and other general optical members. Fluorine used for
Various translucent resins such as polyester, polycarbonate, and polyethylene terephthalate can be used. Further, as long as it has a light-transmitting property with respect to the exposure light, it may be colored. The refractive index of these resins is approximately 1.5. As a method of forming the light-transmitting conductive layer, using a vacuum deposition method, an active reaction deposition method, various sputtering methods, various CVD methods,
Indium tin oxide (ITO), alumina, tin oxide, lead oxide, indium oxide, copper iodide, Au, Ag, N
A light-transmissive thin film made of i, Al, or the like is used, or a conductive resin made of the above-described metal fine particles and a binder resin is used by using a dip coating method, a spray coating method, or the like. Various organic photoconductor layers (OPC) can be used as the photoconductor layer.

The following are examples of preferred image forming members.

After adding a catalyst for synthesizing and polymerizing the plastic material monomer, pour it into a cylindrical mold, seal and fix it with side plates, rotate it at high speed, and heat it appropriately. Promotes uniform polymerization. After completion of the polymerization, the mixture is cooled, the obtained translucent resin substrate is taken out of the mold, cut and, if necessary, subjected to a finishing step to produce a translucent resin substrate for the photosensitive drum of the image forming apparatus ( Centrifugal polymerization method).

As a material for the light-transmitting resin substrate of a light-transmitting plastic molded by centrifugal polymerization, a material obtained by polymerizing a methacrylic acid methyl ester monomer as described above has a light-transmitting property, strength, accuracy, and surface property. In addition, polyethyl methacrylate, polybutyl methacrylate, polyethyl acrylate, polybutyl acrylate, polystyrene, polyimide, polyester, polyvinyl chloride, or the like, or a copolymer thereof can be used. In the centrifugal polymerization method, since the roundness is determined by the mold used for molding, a highly accurate substrate can be obtained. In addition, uneven thickness varies depending on rotation unevenness and viscosity during polymerization and heating conditions during polymerization.

As the conductive layer, indium tin oxide (I
TO), tin oxide, lead oxide, indium oxide, alumina,
A conductive resin obtained by mixing a resin and conductive fine particles made of copper iodide, Au, Ag, Ni, Al, or the like is used. As a film forming method, a dip coating method, a spray coating method, or the like is preferably used. .

The organic photoreceptor layer comprises a charge generating material (CGM)
And a charge transport layer (CTL) containing a charge transport material (CTM) as a main component. The two-layered organic photoreceptor layer is suitable for the present invention because it has a low CGL and thus has a good transparency of image exposure light. The organic photoreceptor layer may have a single-layer structure containing a charge generation material (CGM) and a charge transport material (CTM) in one layer, and may have the single-layer structure or the two-layer structure. Usually contains a binder resin.

In the photosensitive drum 10 having the two-layered organic photosensitive layer, the CGM contained in the CGL includes an azo pigment, an azulenium pigment, and a phthalocyanine photosensitive to light sources such as LEDs and LDs. Pigments and perylene pigments are used. Among them, red to infrared light (600 n
As the CGM of the OPC photoreceptor that is sensitive to light having a wavelength of from about m to about 850 nm, a copper phthalocyanine pigment or a titanyl phthalocyanine pigment is preferably used.

As the binder resin used for CGL, a polyvinyl butyral resin or a polycarbonate resin is used, which is excellent in sensitivity, potential change upon repeated use, and the like. These binder resins can be used alone or as a mixture of two or more.

As a solvent or a dispersion medium used for forming CGL, a ketone-based or halogen-based solvent is preferably used, and the sensitivity, the potential change upon repeated use, and the like are further improved. In addition, these solvents can be used alone or as a mixed solvent of two or more kinds.

The weight ratio of CGM to the binder resin in the CGL is 100: 1 to 1000, the film thickness of the CGL is 0.01 to 10 μm, and the coating method for forming the CGL is a blade. There are various coating methods such as coating, wire bar coating, spray coating, dip coating and slide hopper coating.

Next, as the CTM contained in the CTL, hydrazone compounds, styryl compounds, benzidine compounds, stilbene compounds and the like are used.

The binder resin used in the CTL can be selected from a wide range of insulating resins as appropriate, and preferred binder resins include silicon-alkyd resins, phenol-formaldehyde resins, and poly-N- resins. Insulating resins such as vinyl carbazole and polysilane can be mentioned, and these binder resins can be used alone or in combination of two or more.

The mixing ratio of the binder resin and CTM is 1:
It is set to 10 to 500, and more preferably 1:20 to 150. The thickness of the CTL is set to 1: 100 μm.
~ 50 μm is preferred.

As a coating method, a method similar to CGL can be used.

If necessary, an intermediate layer is provided between the organic photoreceptor layer and the conductive layer. Examples of the intermediate layer include polyvinyl chloride vinyl acetate copolymer, vinyl acetate vinyl acetate maleic acid copolymer, ethyl cellulose, carboxymethyl cellulose and the like. And a resin layer having a thickness of 0.01 to 2 μm, such as a copolymer type or modified type alcohol-soluble polyamide resin.

The use of the plastic cylindrical translucent resin substrate produced by the above-described production method enables uniform thickness, excellent cylindricality and circularity of the cylindrical substrate, and improvement of the image exposure light A photoreceptor drum 10 having no defocus is provided.

Numeral 11 denotes a scorotron charger as a charging means, which performs a charging action on the above-mentioned organic photoreceptor layer of the photoreceptor drum 10 by a grid maintained at a predetermined potential and corona discharge by a discharge wire. 10 is given a uniform potential.

An exposure optical system 12 as an image exposure means for each color of Y, M, C and K has a plurality of exposure systems arranged on a substrate 122 in a main scanning direction parallel to the axis of the photosensitive drum 10. LED (light emitting diode) 12 as a light emitting element
1 are arranged in an array, and a light converging light transmitter (trade name, Selfoc lens) 12b as an imaging element. The Selfoc lens 12b is mounted on a lens holder 12c, for example. 2 and FIG. 3, the exposure element 12a is fixed to a metal casing 12d as a holding member of the exposure element having good thermal conductivity by, for example, an adhesive indicated by a black circle. With the 12a and the SELFOC lens 12b positioned, the lens holder 12c is fixed to the metal casing 12d with, for example, an adhesive indicated by a black circle to form the exposure optical system 12.

Further, as shown in FIG. 4, fins F1, which are radiating means, preferably formed by a plurality of disks at a plurality of locations on the metal casing 12d, are attached by screws provided on the fins F1. The heat generated in the exposure element 12a is quickly transmitted to the fins F1 through the metal casing 12d, and is dissipated and diffused by the fins F1, affecting the displacement between the exposure elements 12a due to thermal expansion and the light quantity fluctuation. Non-uniform temperature distribution and temperature rise of the exposure element 12a are prevented. The exposure optical system 12 provided with the fin F1 at the lower part of the metal casing 12d is attached to a predetermined position of the support member 20 through the fin F1 in the insertion hole H2. Fins F1 are provided inside support member 20.

In addition, FL (phosphor emission), EL (electroluminescence), PL (plasma discharge) and the like are used as the light emitting element.

The exposure optical system 12 for each color uses a spacer block 12e as a wedge-shaped block member, and a main scanning direction with the photosensitive drum 10 and a sub-scanning direction with respect to the rotation direction of the photosensitive drum 10 by a tool or the like in advance. The metal casing 12d is fixed to a support member 20 using a pipe-shaped hollow member such as a cylindrical pipe or a square pipe, which is a common support for the image exposure means for each color.
The spacer block 12e and the spacer block 12e and the support member 20 are fixed to each other with an adhesive indicated by a black circle in FIGS. 2 and 3, for example. The fin F serving as a heat radiating member is aligned with the exposure optical system 12 inside the supporting member 20.
While holding the exposure optical system 12 for each color where 1 is provided, the support member 20 is disposed inside the photoconductor drum 10 with its central axis aligned with the central axis of the photoconductor drum 10. Therefore, image exposure of the photosensitive drum 10 by the exposure optical system 12 is performed perpendicular to the central axis of the photosensitive drum 10.

The distance between the inner peripheral surface of the support member 20 and the outer peripheral surface of the substrate of the photoreceptor drum 10 is determined by the exposure optical system 1.
2, the bottom surface of the exposure optical system 12 has a circumferential surface which is always located outside the inner circumferential surface of the support member 20. The support member 20 does not need to break the cylindrical surface, the strength is maintained, and the exposure optical system 12 can be reliably held at a predetermined imaging position.

A storage unit (not shown), such as an RA, which is read by an image scanner or input by an external signal or the like.
The image signal of each color stored in M is sequentially read from the storage unit through the control unit of the apparatus main body, and input as an electric signal to the exposure optical system 12 for each color, and the LED 121
Are emitted by, for example, a pulse width modulation method (PWM method). The emission wavelength of the light emitting element used in this embodiment is in the range of 600 to 900 nm.

As described above, each of the exposure optical systems 12 provided with the fins F1 is attached to the support member 20 using a pipe-shaped hollow member, is housed inside the substrate of the photoreceptor drum 10, and forms an image forming image to be described later. The body unit is composed,
Lead wires WA from the LEDs 121 for each color, which are drawn from the substrate 122 of each exposure optical system 12 and are connected to the connector C attached to one end of the lower part of the metal casing 12d, are provided inside the support member 20 through the insertion holes H1. You.

After the connection between the connector C and the lead wire WA, the insertion hole H1 is closed together with the lead wire WA with the sealing member S from the inner peripheral side of the support member 20, so that scattered toner, dust and the like to the exposure optical system 12 are thereby formed. Intrusion is prevented. Further, an adhesive or an elastic member such as urethane foam or a rubber material is filled in the insertion hole H1 to prevent toner and dust from entering. As the sealing material S, for example, a hardening type silicone rubber sheet is used, and each insertion hole H1 is closed by an adhesive or the like, thereby maintaining airtightness. As a result, the lead wire WA is connected along the inner peripheral surface of the support member 20 without being strongly bent.
Further, the holding member of the exposure element does not receive the stress due to the lead wire WA and does not come off due to bending of the lead wire WA.

A thin hollow member made of a light metal material such as aluminum or stainless steel, preferably a cylindrical pipe or a square pipe, is used for the support member 20 which is a common support for each exposure optical system 12. Accordingly, the weight and the heat capacity of the supporting member 20 using the metallic hollow member are reduced, and the weight of the image forming unit is reduced, the heat capacity is small, the heat conductivity is good, and the temperature control is achieved. Efficiency is increased. In addition, cylindrical and prismatic pipes are also resistant to mechanical deformation.

Reference numerals 13Y to 13K denote developing units as developing means for accommodating respective developers of yellow (Y), magenta (M), cyan (C) and black (K). On the other hand, there is provided a developing sleeve 130 that rotates in the same direction while maintaining a predetermined gap.

Each of the above-mentioned developing units makes the electrostatic latent image on the photosensitive drum 10 formed by the charging by the scorotron charger 11 and the image exposure by the exposure optical system 12 non-contact by applying a developing bias voltage. Develop reversely in the state of.

The original image is temporarily stored in an image reading device separate from the present device as an image signal read by an image pickup device or an image edited by a computer as image signals for respective colors of Y, M, C and K. And stored.

When the image recording starts, the photosensitive drum driving motor starts to rotate the photosensitive drum 10 in a counterclockwise direction, and at the same time, the charging action of the scorotron charger 11 (Y) starts applying a potential to the photosensitive drum 10. Is done.

After a potential is applied to the photosensitive drum 10, exposure by an electric signal corresponding to a first color signal, ie, an image signal of yellow (Y) is started in the exposure optical system 12 (Y), and An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface by rotational scanning.

The latent image is reversal-developed by the developing device 13 (Y) in a state where the developer on the developing sleeve is not in contact, and a yellow (Y) toner image is formed in accordance with the rotation of the photosensitive drum 10.

Next, the photosensitive drum 10 further applies a scorotron charger 11 on the yellow (Y) toner image.
The potential is given by the charging action of (M), and the exposure optical system 1
Exposure is performed with an electric signal corresponding to the second color signal of 2 (M), that is, the image signal of magenta (M), and the developing device 13
By the non-contact reversal development by (M), a magenta (M) toner image is sequentially superimposed on the yellow (Y) toner image.

By the same process, the scorotron charger 11 (C), the exposure optical system 12 (C) and the developing device 13
(C) further forms a cyan (C) toner image corresponding to the third color signal, and the scorotron charger 11
(K), a black (K) toner image corresponding to the fourth color signal is sequentially superimposed by the exposure optical system 12 (K) and the developing device 13 (K), and is formed within one rotation of the photosensitive drum 10. Then, a color toner image is formed on the peripheral surface.

The photosensitive drum 1 by each of these exposure optical systems
The exposure of the organic photosensitive layer of No. 0 is performed from the inside of the drum through a substrate that is transparent to the above-mentioned exposure wavelength. Therefore, the exposure of the images corresponding to the second, third, and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. At the time of the developing action by each developing device, a developing bias to which a direct current or a further alternating current is applied is applied to the developing sleeve 130, and a jumping development is performed by a one-component or two-component developer accommodated in the developing device, and the developing sleeve 130 is subjected to a transparent development. Non-contact reversal development is performed on the photosensitive drum 10 that grounds the photoconductive layer.

Thus, the color toner image formed on the peripheral surface of the photosensitive drum 10 is temporarily transferred to the peripheral surface of the intermediate transfer belt 14 provided as intermediate transfer means.

The intermediate transfer belt 14 as an intermediate transfer member is an endless rubber belt having a thickness of 0.5 to 2.0 mm, and is made of silicon rubber or urethane rubber at 10 ⁸ to 10 ¹² Ω · cm.
And a resistance value of 10 ¹⁰ to 10 ¹⁶ Ω as a toner filming preventing layer on the outside of the rubber substrate.
-It has a two-layer structure in which a fluorine coating having a thickness of 5 to 50 µm is performed in cm. This layer also preferably has a similar semiconductivity. 0.1-0.5m thickness instead of rubber belt base
m, a semiconductive polyester, polystyrene, polyethylene, polyethylene terephthalate, or the like can also be used. The intermediate transfer belt 14 has rollers 14A, 14B,
The photosensitive drum 10 is stretched between the rollers 14C and 14D, and is circulated clockwise in synchronization with the peripheral speed of the photosensitive drum 10 by the power transmitted to the roller 14D.

The intermediate transfer belt 14 has a belt surface between the rollers 14A and 14B in contact with the peripheral surface of the photosensitive drum 10, and an outer peripheral belt surface of the roller 14C in contact with the transfer roller 15 as a transfer member. A transfer area of the toner image is formed at the contact point.

The color toner image adhered to the peripheral surface of the photosensitive drum 10 is first subjected to intermediate transfer by applying a bias voltage having a polarity opposite to that of the toner to the roller 14B at the contact point with the intermediate transfer belt 14 at first. The image is transferred to the peripheral surface of the belt 14. That is, the color toner image on the drum is conveyed to the transfer area without scattering the toner by the guidance of the roller 14A that is grounded,
The intermediate transfer belt 14 is applied by applying a bias voltage of kV.
It is efficiently transferred to the side.

On the other hand, the transfer paper P as the transfer material is carried out by the operation of the paper feed roller 17 of the paper feed cassette (not shown) and fed to the timing roller 18, and the color toner image on the intermediate transfer belt 14 is formed. Transfer roller 1 in synchronization with conveyance
No. 5 is fed to the transfer area.

The transfer roller 15 is connected to the intermediate transfer belt 14.
The transfer paper P fed in the counterclockwise direction is synchronized with the peripheral speed of the intermediate transfer in the transfer area formed by the nip portion between the transfer roller 15 and the roller 14C in the ground state. The color toner images are successively transferred onto the transfer paper P by applying a bias voltage of the opposite polarity to the toner of 1 to 2 kV to the transfer roller 15 in close contact with the color toner image on the belt 14.

The transfer paper P to which the color toner image has been transferred is neutralized, conveyed to the fixing device 91 via the conveyance plate 19, sandwiched and conveyed between the heat roller 91A and the pressure roller 91B, and heated. After the toner is fused and fixed, the toner is discharged to the outside of the apparatus via a discharge roller 92.

Cleaning devices 100 and 140 as cleaning means are installed on the photosensitive drum 10 and the intermediate transfer belt 14, respectively, and the blades of the respective devices are constantly pressed to remove residual toner adhered thereto. The surrounding surface is always kept clean.

In general, the outer diameter of the photoconductor drum 10 depends on the size of the apparatus and the restrictions imposed by the plurality of scorotron chargers 11, the plurality of developing devices 13, the cleaning device 100, and the like provided on the outer peripheral surface of the photoconductor drum 10. A drum having a diameter between 50 mm and 200 mm is preferably used.
The thickness of the substrate is 2 mm to 10 m corresponding to the drum diameter.
On the other hand, the supporting member 20 for supporting these photosensitive drums 10 has a smaller diameter by the exposure optical system 12 and its image forming distance, and has an outer diameter of 20 mm in the case of a cylindrical pipe.
By setting the thickness of the support member 20 to 0.5 mm to 5 mm corresponding to the outer diameter, the strength is sufficient and the exposure optical systems 12 can be installed on the support member 20 with a margin. Becomes possible.

According to FIG. 5, FIG. 6 and FIG. 2, the support member 20 as the common support is composed of a bearing B1 directly held on the outer periphery and a disk member 22 integrated with the support member 20.
The support member 20 supports the flanges 10A and 10B at both left and right ends of the photosensitive drum 10 in FIG. 5 via a bearing B2 held by the exposure member and has an exposure optical system 12 having a fin F1 attached thereto. Unit 300 as an image forming unit provided with photosensitive drum 10
Is configured.

A disk member 21 is fitted on the outer peripheral surface on the left side of FIG. 5 of the support member 20 provided in the drum unit 300, and a pin 20P is driven into a hole provided in each of the support members 20 so that the disk member 21 is supported. The disk member 22 is fitted into the outer peripheral surface on the right side of FIG. 5 of the support member 20, and the pins 20P are driven into the holes provided in the respective members to fix the disk member 22 to the support member 20. You.

The drum unit 300 is inserted through the insertion hole 30b of the right side plate (right side plate in FIG. 5) 30B, and a cylindrical engaging portion protruded inside the left side plate (left side plate in FIG. 5) 30A. 31. The support member 20
When holding the support member 20, the engaging pin 32 provided on the outer peripheral surface of the engaging portion 31 of the left side plate 30A
A, the fixing angle of the support member 20 is regulated, and each exposure optical system 12 is set at a predetermined position with respect to the apparatus main body.
The correct positional relationship is maintained with respect to the scorotron charger 11 and the developing device 13 arranged along the peripheral surface of the photoconductor drum 10.

Numeral 40 is a disk-shaped flange member as a side member. A cylindrical engaging portion 41 is provided at the center of the disk. The air cylinder 42 is fitted and provided in the provided hole. Further, the flange member 40 is provided with, for example, four divided insertion holes 40H shown in FIG. 6 between the outer periphery of the air cylinder 42 and the inner periphery of the engagement portion 41. A fan FA is disposed at the center of the support member 20 and at the root (right side in FIG. 5) end of the air cylinder 42 provided on the flange member 40.

The air cylinder 42 is moved from the right side in FIG. 5 to the drum unit 300 locked by the engagement portion 31 of the left side plate 30A.
Is inserted, the flange member 40 is positioned by the hole 40B, and is fixed to the right side plate 30B by the screw 51.
Are positioned and supported. The drum unit 300 can be replaced by removing the flange member 40.

By the operation of the fan FA disposed at the root (right side in FIG. 5) end of the air cylinder 42, air is released from the air cylinder 42.
Of the air cylinder 42, which flows into the inside of the air cylinder 42 and flows out from the end of the air cylinder 42 opposite to the fan FA, passes through the inner peripheral surface of the support member 20 on the outer peripheral surface of the air cylinder 42, and the insertion hole 40 </ b> H of the flange member 40.
And is discharged from the support member 20 through the At this time, an air flow is formed through the fins F1, which are integrally attached to the exposure optical system 12 and provided inside the support member 20, which are heat radiation members, and the fins F1 are cooled by the air flow. By cooling the fin F1, the exposure optical system 12 provided with the exposure element 12a having the LED 121 that generates heat is cooled. The operation of the fan FA is controlled by a temperature sensor (not shown), and the temperature of the exposure element 12a, particularly, the temperature of the LED 121 can be maintained at an appropriate temperature.

As described above, the heat radiation of the heat radiating member prevents a change in the light amount of the heating element due to the heat generated from the light emitting element and a positional shift of the light emitting element due to the thermal deformation of the exposure element. In addition, more appropriate heat radiation can be achieved by the flow of air.

An LED provided on the plurality of exposure elements 12a and disposed through the inside of the support member 20 in the form of a pipe.
Lead wire WA from 121 is pulled out from insertion hole 40H of flange member 40.

With the drum unit 300 mounted on the left and right side plates 30A and 30B, the photosensitive drum 10 can be rotated by the power of a driving gear G that meshes with the gear 10G of the flange 10A. A developing device 13 is inserted, and abutting rollers 13 are attached to the end surfaces with reference to the outer peripheral surfaces of the disk members 21 and 22.
The developing unit 13 is positioned with respect to the photosensitive drum 10 by abutment with 0A, and is fixed to the apparatus main body by screws (not shown) or the like. Therefore, since the photosensitive drum 10 does not receive a load due to the pressure contact of the developing unit 13, the photosensitive drum 10 having no cylindrical shape does not cause distortion or deformation, and even between toner images formed on the drum surface. There is no deviation due to deformation or the like. Further, since the vibration of the developing device 13 is not directly transmitted to the photosensitive drum 10, blurring or the like during image exposure does not occur. In this way, the photosensitive drum 10 is constantly driven and rotated while maintaining a highly accurate roundness, and as a result, a high-quality color image is formed.

With the drum unit 300 mounted on the left and right side plates 30A, 30B, the developing means, charging means, cleaning means, intermediate transfer member and the like described in FIG. 1 are mounted at predetermined positions.

Another example of the location where the heat radiating member is provided will be described with reference to FIGS. 7, 8, and 5. FIG. FIG. 7 is a diagram illustrating a first example of a heat radiating member provided on the common support, and FIG. 8 is a diagram illustrating a second example of a heat radiating member provided on the common support.

As another example of the place where the heat radiation member is provided,
The heat radiation member is provided directly on the support member 20 which is a common support.

As shown in FIG. 7, inside the pipe-shaped support member 20 as a hollow member, a plurality of fins F2 which are comb-shaped heat radiation members extending directly from the inner wall of the support member 20 toward the center. Provide. The fins F2 are provided to face the respective positions of the exposure optical systems 12 attached to the support member 20. Preferably, the fin F2 is
The one molded by drawing together with 0 is used.

As described above with reference to FIG. 5, the operation of the fan FA disposed at the root (right side in FIG. 5) end of the air cylinder 42 causes air to flow into the air cylinder 42, Air that has flowed out from the end of the air cylinder 42 on the opposite side to the FA passes through the inner peripheral surface of the pipe-shaped support member 20 on the outer peripheral surface of the air cylinder 42 and is discharged from the support member 20 through the insertion hole 40H of the flange member 40. You.

At this time, the support member 2 is provided inside the support member 20.
Fin 2, which is a heat dissipating member provided integrally with
An air flow is formed through the fin F2, and the fin F2 is cooled by the air flow. L that generates heat by cooling the fin F2
The exposure optical system 12 provided with the exposure element 12a having the ED 121 is cooled. The operation of the fan FA is controlled by a temperature sensor (not shown), and the temperature of the exposure element 12a is controlled.
In particular, it is possible to keep the temperature of the LED 121 at an appropriate temperature.

As described above, the heat radiation of the heat radiating member prevents a change in the light amount of the heat generating element due to the heat generated from the light emitting element and the displacement of the light emitting element due to the thermal deformation of the exposure element. In addition, more appropriate heat radiation can be achieved by the flow of air.

As shown in FIG. 8, the support member 20 is provided inside the pipe-shaped support member 20 as the hollow member.
A plurality of fins F3, which are comb-shaped heat dissipating members, are provided orthogonal to a plate member extending in the center direction from the inner wall of the fin F3. Fin F3
Are provided to face the respective positions of the exposure optical systems 12 attached to the support member 20. Preferably fin F
Reference numeral 3 denotes a member integrally formed with the support member 20 by drawing.

As described above with reference to FIG. 5, air is introduced into the air cylinder 42 by the operation of the fan FA disposed at the root (right side in FIG. 5) end of the air cylinder 42. Air that has flowed out from the end of the air cylinder 42 on the opposite side to the FA passes through the inner peripheral surface of the pipe-shaped support member 20 on the outer peripheral surface of the air cylinder 42 and is discharged from the support member 20 through the insertion hole 40H of the flange member 40. You.

At this time, the support member 2 is provided inside the support member 20.
Fin F3 which is a heat dissipating member provided integrally with
And an air flow is formed, and the fin F3 is cooled by the air flow. L that generates heat by cooling the fin F3
The exposure optical system 12 provided with the exposure element 12a having the ED 121 is cooled. The operation of the fan FA is controlled by a temperature sensor (not shown), and the temperature of the exposure element 12a is controlled.
In particular, it is possible to keep the temperature of the LED 121 at an appropriate temperature.

As described above, the heat radiation of the heat radiating member prevents a change in the light amount of the heat generating element due to the heat generated from the light emitting element and a positional shift of the light emitting element due to the thermal deformation of the exposure element. In addition, more appropriate heat radiation can be achieved by the flow of air.

In the above embodiment, in order to keep the temperature of the image exposing means constant, in addition to the temperature sensor, together with the cooling means such as the heat radiating member and the fan, a heater (not shown) as a heating means is used for each image exposing means. It is effective to perform temperature control by providing the means, or to perform a temperature control as a configuration for generating an airflow heated to a predetermined temperature by combining a heater and a fan.

[0076]

According to the first to fourth aspects of the present invention, the heat radiation of the heat radiating member prevents a change in the amount of light of the heat generating element due to the heat generated from the light emitting element and a displacement of the light emitting element due to the thermal deformation of the exposure element.

According to the fifth aspect, more appropriate heat radiation becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a diagram showing an image exposure unit.

FIG. 3 is a perspective view of FIG. 2;

FIG. 4 is a view showing a heat radiation member provided in the image exposure means.

FIG. 5 is a sectional configuration diagram of an image forming unit.

FIG. 6 is a view showing a flange member of FIG. 5;

FIG. 7 is a diagram showing a first example of a heat radiation member provided on a common support.

FIG. 8 is a view showing a second example of the heat radiation member provided on the common support.

[Explanation of symbols]

 Reference Signs List 10 photoconductor drum 11 scorotron charger 12 exposure optical system 12a exposure element 12d metal casing 20 support member 40 flange member 42 air cylinder 121 LED F1, F2, F3 fin FA fan

Claims (5)

[Claims] 1. An image forming apparatus comprising: a rotating image forming body; and an image exposing means for providing an exposing element in which a plurality of light emitting elements are arranged in a line on a metal casing. An image forming apparatus, wherein an image forming body and a support member for supporting the image exposure means are integrally provided, the support member is a hollow member, and a heat dissipation member is provided inside. 2. The image forming apparatus according to claim 1, wherein the heat radiating member is provided to face a position of an image exposing means attached to the supporting member. 3. The image forming apparatus according to claim 1, wherein the heat radiation member is integrated with the image exposure unit. 4. The image forming apparatus according to claim 1, wherein the heat radiation member is integrated with the support member. 5. The image forming apparatus according to claim 1, wherein air flows in from a central portion of the support member, and forms an air flow through a heat radiation member provided inside the support member.