JPH04174454A - electrophotographic recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application fields] This invention is applicable to, for example, copying machines and laser printers.

The present invention relates to an electrophotographic recording device having a belt-shaped photoreceptor in an electrophotographic process such as a facsimile, and particularly to prevention of curling of the photoreceptor.

[Prior Art] Printers, copying machines, and the like having belt-shaped photoreceptors are used in electrophotographic processes.

FIG. 3 is a structural diagram showing an outline of a laser printer having a belt-shaped photoreceptor.

As shown in the figure, in a laser printer 20, a transfer paper 2 fed from a paper feeder 1 in six directions of arrows is timed by a pair of registration rollers 3, and a latent image formed by a belt-shaped photoreceptor 4 is transferred to the transfer paper 2. It is transported to a carrier. The photoreceptor belt 4 runs clockwise, and its surface is charged by the charger 5 at this time. Then, a laser beam from the laser unit 6 is irradiated, and an electrostatic latent image is formed on the photoreceptor belt 4. This latent image is made visible by toner when passing through the developing device 7, and a toner image is formed. This toner image is transferred to the transfer paper 2 conveyed to the photoreceptor belt 4 under the action of the transfer charger 8, and the toner image is transferred to the transfer paper 2 after transfer.
are separated by the curvature of the photoreceptor belt 4. Thereafter, the toner image is fixed on the transfer paper 2 by a fixing device 9, and then the transfer paper 2 passes through first paper discharge rollers 10 and 11.

The transfer paper 2 that has passed through the first paper ejection rollers 10 and 11 is either ejected in the direction of arrow C with the image side facing up according to the direction switching of the switching claw 12, or is ejected in the direction of arrow C with the image side facing up, or
．． 24, and the second
printer 20 in direction B via paper ejection rollers 14 and 15.
The paper is ejected to the upper paper ejection tray 16 with the image side facing down.

On the other hand, the photoreceptor belt 4 after transfer is cleaned by a cleaning device 17.
The residual toner is removed by the static elimination lamp 18.
The residual charges are removed and the print is prepared for the next print.

The printer 20 is composed of an upper frame 30 and a lower g++ frame 40, and inside the upper frame 30, the above-described laser unit 6, static elimination lamp 18, charger 5, etc. are provided. Furthermore, the upper frame 30
A photoreceptor 4 and a cleaning device 17 are removably supported at the bottom thereof. This upper frame 30 has a rotating pin 2
1 is a common support shaft with the lower frame 40, and is integrally carved into the frame 40 with the main cover 31, so that it can be opened and closed as shown in FIG. In this case, the rotating bin 21 is placed on the back side of the printer body, and the upper frame 30 is opened and closed on the front side.

Further, when the upper frame 30 is opened as shown in FIG. 4, a circuit of an internal safety switch (not shown) is opened, and at least the drive motor and high voltage circuit are turned off.

26 is an operation display unit, which is rotatable around the shaft 21.

33 is a leg made of rubber or plastic arranged on the lower frame 40, and 34 is a paper feeding tray that stores the transfer paper 2.

In the laser printer 20 configured as described above, the photoreceptor belt 4 is driven by a roller to perform predetermined process steps such as charging, exposure, development, transfer, cleaning, and static elimination. , as shown in the partial configuration diagram of FIG. Transfer roller 36. It is supported by a cleaning roller 37 and placed under a certain tension. - During printing, the photosensitive belt 4 is driven by the drive roller 35 and rotates clockwise, stops rotating when printing is completed, and remains under tension during standby.

[Problem to be solved by the invention]

As mentioned above, since the photoreceptor belt 4 stops at a certain point when not in operation, if the photoreceptor belt 4 is left in the non-operation state for a long time, it may tend to curl at the positions where it contacts the rollers 35, 36 and 37. This causes unevenness to occur on the photoreceptor belt 4. In particular, when the printer is in standby mode with the power on, the fixing heater is on and the temperature inside the printer is high. At this time, curling tends to occur, and in particular, curling tends to occur particularly in the portion of the transfer roller 36 closest to the fixing heater.

When unevenness occurs on the photoreceptor belt 4 due to this curling tendency, the adhesion between the photoreceptor belt 4 and the transfer paper 2 in the transfer section becomes poor, resulting in missing or blurred images due to poor transfer, and the contact state occurs in the development section. There is a disadvantage that image quality such as development unevenness is deteriorated due to differences.

Furthermore, if the same part of the photoreceptor belt 4 is exposed to the part closest to the fixing heater for a long time, there is a risk that that part will change in quality.

This invention was made to solve these shortcomings, and it is possible to prevent curling even if the photoconductor is on standby for a long time, prevent deterioration of the photoreceptor, and always form a good output image. The purpose of this invention is to obtain an electrophotographic recording device that can perform the following steps.

Means for Solving the Problem] An electrophotographic recording apparatus according to the present invention includes a stop state detection timer that detects that the belt-shaped photoreceptor has stopped for a certain period of time after entering a standby state, and a stop state detection The present invention is characterized in that it includes a belt drive timer that sends out a drive signal to drive a belt-shaped photoreceptor for a predetermined period of time when a time signal is output from the timer.

Preferably, the belt drive timer receives a heater operation signal of the fixing device and sends out a drive signal to drive the belt-shaped photoreceptor for a predetermined period of time when the time signal from the stop state detection timer is output.

[Effect]

In this invention, when it is detected that the belt-shaped photoreceptor is in a standby state and stopped for a predetermined period of time, the belt drive timer is activated by a high-power time signal from the stop state detection timer. A drive signal is sent to move the belt-shaped photoreceptor a certain distance.

When moving this belt-shaped photoconductor a certain distance, the belt-shaped photoconductor is stopped for a certain period of time, and then moved in synchronization with the on/off operation of the heater of the fixing device. , the photoreceptor can be moved to follow changes in the temperature inside the machine.

〔Example〕

FIG. 1 shows a laser printer 20 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a photoreceptor belt operation control section of FIG. As shown in the figure, the laser printer 20 includes a belt driving means 51 that drives the photoreceptor belt 4 during printing, and a photosensitive belt 4 when the time limit is set to, for example, 10 minutes and receives a signal from the belt driving means 51 and is in a standby state. A stop state detection timer 52 detects the stop time of the body belt 4, and when a time signal is received from the stop state detection timer 52, a heater operation signal is received from the heater control means 53 of the fixing device, and the timer 52 detects the stop time of the body belt 4. It has a belt drive timer 54 that sends a drive signal to the belt drive means 51 and an input means 55.

The operation of the laser printer 2Q configured as described above will be explained with reference to the flowchart shown in FIG.

The laser printer 20 enters a standby state when the power is turned on (
Step Sl). When a print signal is input from the input means 55 in this state (step S2), the belt drive means 51 operates to rotate the drive roller 35 and perform a series of printing operations while rotating the photoreceptor belt 4 ( Step S2゜53). After the printing on the transfer paper 2 is completed and it is ejected, if the power remains on, the transfer paper 2 enters the standby state again (step S5).

During this standby state, a stop signal is sent from the belt drive means 51 to the stop state detection timer 52.

Then, if the next print signal is not input from the input means 55 and the standby state continues even after a certain period of time, for example, 10 minutes, and a stop signal is sent to the stop state detection timer 52 (step S6), the stop state The detection timer 52 sends a time signal to the belt drive timer 54 (step S7).

After receiving the time signal from the stop state detection timer 52, the belt drive timer 54 sends a drive signal for, for example, one second to the belt drive means 51 when a heater off signal for the fixing device 9 is input from the heater control means 53. Belt drive means 5
1 is activated (step S9). The drive roller 53 is rotated by the operation of the belt drive means 51, and the photoreceptor belt 4 is moved for one second (step 510).

Therefore, the linear velocity of the drive roller 35 is, for example, 60 mm.
/second, the photoreceptor belt 4 moves 60mm,
Shift the position in contact with each roller.

The above operations are repeated while the laser printer 2 is on standby.
The position of the photoreceptor belt 4 is sequentially moved.

When the next print signal is input, the above operation is stopped, the photoreceptor belt 4 is moved to the home position, and the print operation is performed.

In this way, when the laser printer 20 is in a standby state for a certain period of time and the temperature of the fixing device 9 reaches its highest and the heater is turned off, the photoreceptor belt 4 is moved, so that heat can be removed by moving the photoreceptor belt 4, such as a polyester film. It is possible to prevent the same location of the photoreceptor belt 4, which is made of resin material that is easily affected, from being exposed to a high temperature part.

In the above embodiment, the laser printer 20 is in a standby state for a certain period of time, and when the temperature of the fixing device 9 reaches the highest level and the heater is turned off, the photoreceptor belt 4 is moved. The photoreceptor belt 4 may be moved when the heater is turned on, or when the laser printer 20 enters the standby state and a certain period of time has elapsed.

〔Effect of the invention〕

As explained above, this invention moves the belt-shaped photoreceptor a certain distance when it is detected that the belt-shaped photoreceptor is in a standby state and stopped for a predetermined period of time. , it is possible to prevent curling of the photoreceptor near the roller.

In addition, when moving the belt-shaped photoconductor during standby, by moving the belt-shaped photoconductor in synchronization with the on/off operation of the heater of the fixing device, the photoconductor can be moved to follow changes in the internal temperature of the machine. Because it can be moved and the same part of the photoreceptor can be prevented from being exposed to high temperatures,
It is also possible to prevent the photoreceptor from being affected by high temperatures.

Therefore, deterioration in image quality such as transfer missing can be prevented, and high-quality images can always be formed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a photoreceptor belt operation control section of a laser printer according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of the above embodiment. FIGS. 3 and 4 are overviews of the laser printer. FIG. 5 is a partial configuration diagram showing the photoreceptor belt. 4; Photoreceptor belt 51; Belt drive means; 52; Stop state check timer; 53; Heater control means; 54; Belt drive timer; 55; Input means.

Claims (1)

[Scope of Claims] 1. In an electrophotographic recording apparatus having a belt-shaped photoconductor, a stop state detection timer detects that the belt-shaped photoconductor has stopped for a certain period of time after being in a standby state; An electrophotographic recording apparatus comprising: a belt drive timer that sends out a drive signal to drive a belt-shaped photoreceptor for a predetermined period of time when a time signal from the stop state detection timer is issued. 2. The belt drive timer receives the operation signal of the heater of the fixing device when the time signal from the stop state detection timer is output, and sends out a drive signal to drive the belt-shaped photoreceptor for a certain period of time. Electrophotographic recording device.