JP2002139874A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a photoreceptor and a belt from being damaged when a user tries to draw out a photoreceptor unit or a developing unit by opening the opening/closing cover of a device main body in the midst of printing. SOLUTION: In this image forming device, a plurality of image forming units are constituted to be attachable/detachable by opening/closing the opening/ closing cover of the device main body, and power is supplied to an image forming member through an interlock circuit 37 supplying power and interrupting the power supply according to opening/closing the opening/closing cover. In the device, the power is supplied to the image forming units 42 and 43 abutting on and separating from each other among the image forming units separately from the circuit 37.

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 or the like which uses an electrophotographic method or the like, in which various drive power sources are cut off when an opening / closing cover of an apparatus body is opened. Device.

[0002]

2. Description of the Related Art An image forming apparatus is provided with a drive power supply for a laser light emitting unit, a high-voltage power supply for charging, development and transfer, and a drive power supply for a photoconductor, a transfer belt, a fixing device, and a transfer material transport system. In this image forming apparatus, an interlock circuit for shutting off a predetermined power supply is provided in order to ensure user safety when the opening / closing cover of the apparatus main body is opened during printing. Conventionally, this interlock circuit is usually constituted by one system.

[0003]

Incidentally, in the image forming apparatus, there is a system in which a photosensitive member, a developing device, a transfer device, and the like are unitized, and an opening / closing cover of an apparatus main body is opened and closed to be detachable. In addition, the developing device is separated from the photoconductor, and the tension of the belt of the photoconductor or the transfer device is released.

[0006] However, as shown in FIG. 6, in step S 51, the user sets the front cover (open / close cover) during printing.
Is opened, the interlock circuit is turned off in step S52, the drive system, the high-voltage power supply, and the power supply to the laser are shut off. As shown in step S53, the developing device contacts and the transfer belt tension is stretched. It remains as it is. This state is the same as the state during printing. Next, when the developing device lock lever or the photoconductor lock lever is released in step S54, as shown in step S55, the photoconductor is damaged when the developing device is pulled out, and the photoconductor is damaged when the photoconductor is pulled out. As described above, when the interlock circuit operates and all power is turned off, the developing device comes into contact with the photoconductor and the belt is tensioned. However, there is a problem that the photoconductor and the belt may be damaged if they are pulled out.

The present invention solves the above-mentioned conventional problem. When the user opens the opening / closing cover of the apparatus main body during printing and tries to pull out the photosensitive member unit or the developing unit, the photosensitive member or the belt is removed. It is an object to provide an image forming apparatus capable of preventing damage.

[0006]

According to a first aspect of the present invention, there is provided an image forming apparatus, wherein an opening / closing cover of an apparatus main body is opened / closed so that a plurality of image forming units can be attached / detached. In an image forming apparatus that supplies power to an image forming member via an interlock circuit that supplies and shuts off power to the image forming unit, the image forming unit that contacts and separates between the image forming units includes the interlock circuit. According to a second aspect of the present invention, the image forming unit is a developing unit, a photosensitive unit and a transfer unit, and the photosensitive unit or the transfer unit is provided. The unit is constituted by a belt, and the belt is provided with a tension stretching / releasing mechanism.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an embodiment of the image forming apparatus of the present invention. This image forming apparatus is a color electrophotographic printer capable of forming a full-color image with four color toners. However, the present invention is not limited to this, and all image forming apparatuses such as a copying machine, a facsimile, etc. Applicable to

[0008] The image forming apparatus 1 includes a photoconductor 2 in an apparatus main body.
Is arranged, and is rotationally driven by a driving motor M1 in the direction of the arrow shown in the figure. Around the photosensitive member 2, a charging roller 3 as a charging unit and a photosensitive member 2
An exposure unit 4 for forming an electrostatic latent image thereon, a developing unit U1 for developing the electrostatic latent image formed on the photoconductor 2, and an intermediate transfer of a toner image formed on the photoconductor 3 A transfer unit U2 for transferring the image on the belt 5 and a cleaning unit 6 for removing the toner remaining on the photoconductor 3 are arranged. The photoreceptor 2, the charging roller 3, and the cleaning unit 6 are unitized as a photoreceptor unit U3, and can be detachably attached to the apparatus main body by opening the opening / closing cover 31 (FIG. 3) of the apparatus main body together with the developing unit U1 and the transfer unit U2. It is configured to be attachable.

The developing unit U1 comprises a developing unit for yellow 7Y, a developing unit for cyan 7C, a developing unit for magenta 7M and a developing unit for black 7K. Each developing unit includes a developing roller 7a, and a driving motor M2, Driven by M3. And these developing units 7Y, 7C, 7M, 7K
Are respectively connected to the photosensitive members 2 by the separation / contact clutches C1 to C4.
And only one developing roller 7a of one developing unit is selectively provided for each rotation of the photoconductor 2.
Abutment.

The transfer unit U2 includes an intermediate transfer belt 5,
A primary transfer electrode roller 7 for uniformly charging the intermediate transfer belt 5, a drive roller 9 for rotating the intermediate transfer belt 5 by the drive motor M <b> 1, and a tension roller 10 for tensioning the intermediate transfer belt 5. A secondary transfer roller 11 for transferring the toner image on the intermediate transfer belt 5 to a transfer material, a cleaning unit 12 for removing residual toner on the intermediate transfer belt 5, and an intermediate transfer of the toner image on the photoreceptor 2. It is composed of a primary transfer roller 13 for transferring to the belt 5 and the like. The secondary transfer roller 11 and the cleaning unit 12 can be separated and contacted with the intermediate transfer belt 5 by a driving motor M4 and separation and contact clutches C5 and C6 as shown by arrows in the drawing. The primary transfer roller 13 is configured to be movable inward of the intermediate transfer belt 5 by a driving motor M4 and a tension clutch C7, as shown by an arrow in the drawing, and to stretch or release the belt tension.

A main paper feed cassette 14 is provided in the apparatus main body, and an auxiliary paper feed cassette 15 is provided on a side surface of the apparatus main body.
Further, a paper discharge tray 16 for storing a transfer material on which an image has been transferred is provided at an upper portion of the apparatus main body, and a transfer material transport path 17 is provided between the paper feed cassettes 14 and 15 and the paper discharge tray 16. Are formed. In the transfer material transport path 17,
A gate roller 19 for controlling transfer timing of the transfer material is provided upstream of the secondary transfer roller 11, and a fixing unit U4 driven by a driving motor M5 is provided downstream of the secondary transfer roller 11. I have.

The main body paper feed cassette 14 and the auxiliary paper feed cassette 15 are provided with a pickup roller 20 and a transport roller 21 for feeding the transfer material to the transfer material transport path 17 one by one. Is driven by turning on and off a clutch (not shown). Main unit paper cassette 14
The auxiliary paper feed cassette 15 is unitized as a main paper feed unit U5 and an auxiliary paper feed unit U6, and is configured to be detachable from the apparatus main body.

The operation of the image forming apparatus having the above configuration will be described. When an image forming signal is input from a computer (not shown), the photosensitive member 2 and the intermediate transfer belt 5
Is driven to rotate, and first, the surface of the photoconductor 2 is
The surface of the uniformly charged photoreceptor 2 is selectively exposed L in accordance with the image information of the first color (for example, yellow) by the exposure unit 4, and the electrostatic latent image of yellow is An image is formed.

Next, a yellow developing device 7 is
Only the Y developing roller 7a comes into contact, whereby a yellow electrostatic latent image toner image is formed on the photoconductor 2. A primary transfer voltage is applied to the side end of the intermediate transfer belt 5 by the primary transfer electrode roller 7 in a polarity opposite to the charging polarity of the toner image, and the toner image formed on the photoconductor 2 is transferred by the primary transfer roller 13. The image is transferred onto the intermediate transfer belt 5. At this time, the secondary transfer roller 11 and the cleaning unit 1
2 is separated from the intermediate transfer belt 5 and retracted. After the residual toner on the photoreceptor 2 is removed by the cleaning unit 6 each time, the surface of the photoreceptor 2 is discharged by a discharging unit (not shown).

The above operation corresponds to the second, third and fourth colors of the image forming signal, and the latent image formation, development and transfer by one rotation of the photosensitive member 2 and the intermediate transfer belt 5 are repeated. Four color toner images corresponding to the contents of the image forming signals are superimposed and transferred on the intermediate transfer belt 5. Then, the full-color image is transferred to the secondary transfer roller 11.
When the gate roller 19 reaches the timing, the transfer material is supplied to the secondary transfer roller 11 via the transfer material transport path 17, and at this time, the secondary transfer roller 11 and the cleaning unit 12 abut on the intermediate transfer belt 5. At the same time, a secondary transfer voltage is applied to the secondary transfer roller 11, and the full-color toner image on the intermediate transfer belt 5 is transferred onto the transfer material. The residual toner on the intermediate transfer belt 5 is removed by the cleaning unit 12. The transfer image transferred onto the transfer material is fixed by the fixing unit U4 and is discharged to the discharge tray 16.

FIG. 2 is a diagram for explaining the separation / contact of the developing device and the belt tension stretching / releasing operation in FIG.

FIG. 2A shows a state in which printing is in progress. The separation / contact clutch C4 is turned on, the K developing unit 7K moves to the arrow shown in FIG.
Is turned on, the tension roller 10 and the primary transfer roller 13 move in the direction of the arrow in the figure, and tension the intermediate transfer belt 5.

FIG. 2B shows a standby state until the next printing operation after printing is completed. The release / contact clutch C4 is turned off, the K developing device 7K moves to the arrow shown in FIG. The tension clutch C7 is turned off, and the tension roller 10 and the primary transfer roller 13 move in the direction of the arrow in the figure to release the tension on the intermediate transfer belt 5. Thus, creep and deformation of the belt can be prevented by loosening the tension of the belt.

FIG. 3 is a schematic view of the appearance of the image forming apparatus. A front cover (open / close cover) 31 is provided on the front surface of the apparatus main body 30 so as to be openable and closable.
The transfer unit U2 and the photoconductor unit U3 are
It is made detachable from 0. Then, an interlock switch S1 for supplying and shutting off power by opening and closing the front cover 31, and an interlock switch S2, S for supplying and shutting off power by attaching and detaching each unit U1, U2, U3.
3 and S4 are provided. A fixing unit U4 is detachably provided on a side surface of the apparatus main body 30, and an interlock switch S5 that supplies and shuts off power by opening and closing a cover of the fixing unit U4, and supplies and shuts off power by sliding the fixing unit U4. An interlock switch S6 is provided.

An auxiliary paper feed unit U6 is provided on a side surface of the apparatus main body 30, and an interlock switch S7 for supplying and shutting off power by sliding the auxiliary paper feed unit U6 is provided. On the side of the apparatus main body 30, a main body paper supply cover 32 and a paper discharge cover 33 are provided so as to be openable and closable, and interlock switches S8 and S9 for supplying and shutting off power by opening and closing the respective covers are provided. . Further, an upper cover 34 is provided on the upper surface of the apparatus main body 30 so as to be openable and closable, and an interlock switch S10 for supplying and shutting off power by opening and closing the cover is provided.

FIGS. 4 and 5 show an embodiment of the image forming apparatus of the present invention. FIG. 4 is a configuration diagram of a control system, and FIG. 5 is a diagram for explaining the operation.

In FIG. 4, AC 100 V of the power supply 35
The power supply is connected to the fixing unit (heater) 36 and the DC 24
The V and 5V power supplies are supplied via a first interlock circuit 37 (the interlock switch 37a and the relays R1 and R2 are collectively referred to as an interlock circuit 37) to a paper feed / paper transport unit (paper feed drive / electromagnetic clutch). ) 38, a high-voltage power supply (charging, development, transfer bias application) 39, and an exposure unit (laser irradiation) 40.

The 24 V power supply of the power supply section 35 is supplied to a second interlock circuit 41 (interlock switch 41).
a and a relay R3 are collectively referred to as an interlock circuit 41), a developing unit (developing unit driving / developing unit separation / contact mechanism driving in FIG. 1) 42, and a transfer unit (transfer belt driving / transfer belt tension tension). / Release mechanism drive) 43. The developing unit 42 is, specifically, the developing device driving motors M1, M2 and the separation / contact clutches C1 to C4 of FIG. 1, and the transfer unit 43 is the transfer belt driving motor M1, the transfer belt tension tension / Release clutches C5 to C7.

The interlock switch 37a of the first interlock circuit 37 includes an interlock switch S1 for supplying and shutting off power by opening and closing the front cover 31 and a power supply by opening and closing the cover of the fixing unit U4 as described with reference to FIG. Switch S for supplying and shutting off
5, an interlock switch S6 for supplying and interrupting power by sliding the fixing unit U4, an interlock switch S7 for supplying and interrupting power by sliding the auxiliary paper feeding unit U6, and opening and closing of the main body paper supply cover 32 and the paper ejection cover 33. Are connected in series with interlock switches S8 and S9 for supplying and shutting off power and an interlock switch S10 for supplying and shutting off power by opening and closing the upper cover 34. The second interlock circuit 41 includes a developing unit U1, a transfer unit U2,
The configuration is such that interlock switches S2, S3, and S4 for supplying and shutting off the power supply by attaching and detaching the photoconductor unit U3 are connected in series.

Next, the operation of the present invention will be described with reference to FIG. If the user opens the front cover (open / close cover) during printing in step S41, the process proceeds to step S42.
As a result, the first interlock circuit 37 is turned off, and the power supply to the paper feed / paper transport unit 38, the high voltage power supply 39, and the exposure unit 40 is cut off. Next, in step S43, the developing device is separated, and the transfer belt tension is released. This state is the same as the standby state from the end of printing to the next printing operation. Next, when the developing device lock lever or the photosensitive member lock lever is released in step S44, as shown in step S45, the photosensitive member is not damaged even if the developing device is pulled out, and the photosensitive member is not damaged even if the photosensitive member is pulled out. . Note that the second interlock circuit 41 is turned off simultaneously with the removal, and the power supply is cut off.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above embodiment, a photoconductor drum is used as a photoconductor and a transfer belt is used as an intermediate transfer member. However, a photoconductor belt and a transfer drum may be used.

Further, in the above-described embodiment, the two systems of the interlock circuit are the separation / contact of the developing device and the tension / release of the belt tension. However, the main body paper feeding unit U5 and the auxiliary paper feeding unit U6 are used. May be targeted for separation and contact with the transfer material.

[0028]

As is apparent from the above description, it is possible to prevent the photosensitive member and the belt from being damaged when the user tries to pull out the photosensitive member unit and the developing unit by opening the opening / closing cover of the apparatus main body during printing. Can be.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of an image forming apparatus of the present invention.

FIG. 2 is a view for explaining separation / contact of a developing device and belt tension stretching / releasing operation in FIG. 1;

FIG. 3 is a schematic diagram illustrating an appearance of the image forming apparatus illustrated in FIG. 1;

FIG. 4 is a configuration diagram of a control system showing one embodiment of the image forming apparatus of the present invention.

FIG. 5 is a diagram for explaining the operation of FIG. 4;

FIG. 6 is a diagram for explaining a problem of the present invention.

[Explanation of symbols]

 2 Photoconductor 5 Intermediate transfer belt 7Y, 7C, 7M, 7K Developing device 31 Opening / closing cover 37 First interlock circuit 41 Second interlock circuit U1 Developing unit U2 Transfer unit U3 Photoreceptor units C1 to C4: separation / contact clutch C7: tension clutch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G03G 21/00 520 B41J 29/12 C 2H071 F term (reference) 2C061 AP03 AP04 AQ06 CD07 CD14 CD16 2H027 ZA04 2H030 AA06 AA07 AB02 AD19 BB42 2H032 BA09 BA23 2H035 CA05 CB06 CF01 2H071 BA20 DA08 DA09 DA15 DA34 EA16 EA18

Claims (2)

[Claims] A power supply is supplied to an image forming member via an interlock circuit which supplies and shuts off power by opening and closing the openable cover by opening and closing an openable cover of the apparatus main body and opening and closing the openable cover. In the image forming apparatus to be supplied, an image forming unit that contacts and separates the image forming units from each other is supplied with a power supply separate from the interlock circuit. 2. The image forming unit includes a developing unit, a photoreceptor unit and a transfer unit. The photoreceptor unit or the transfer unit comprises a belt, and the belt has a tension stretching / releasing mechanism. The image forming apparatus according to claim 1, wherein: