JPH08123298A - Image forming device - Google Patents

Abstract

PURPOSE: To control a fan motor with the optimum driving power without consuming the unnecessary current, by controlling the fan motor for an image forming device and the fan motor for the both side unit in a state of high sped rotation, low speed rotation and stopping respectively corresponding to the specified conditions for instance, such as the standby, the single side successive print and the both side successive print. CONSTITUTION: The speed of the fan motor for the image forming device and fan motor for the both side unit device are controlled corresponding to the respective states such as the standby, the single side successive print, the both side successive print. The rotary speed of fan motor is controlled in three ways by the output signal form the two ports A and B by the control part 100 of the both side unit device and the image forming device. The control part 100 controls the entire operations of the both side unit and the image forming device, is provided with the CPU, the memory such as the ROM for storing the control procedure by the CPU, the memory such as the RAM furnished with the operation area for the CPU and the nonvolatile memory.

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 laser beam printer or a copying machine.

[0002]

2. Description of the Related Art An image forming apparatus for visualizing an image stored in a memory by fixing a developer, that is, a toner on a print sheet is typified by a laser beam printer or a copying machine, and is a quiet recording apparatus. Widely used due to its sex.

The printing operation in the image forming apparatus is completed by a known electrophotographic technique, that is, by exposing, developing, and transferring, visualizing the toner on the printing paper, and finally fixing the toner on the printing paper. .

As an example of such an image forming apparatus, FIG.
Shows the schematic structure of the electrophotographic printer.

In FIG. 8, reference numeral 50 is an image forming apparatus, and 51 is a double-sided unit apparatus which can be attached to and detached from the image forming apparatus.

In the image forming apparatus 50, reference numeral 500 denotes a photosensitive drum which is an electrostatic latent image carrier.
Above 0, a charging roller 501 that uniformly charges the surface of the photosensitive drum 500 is in contact with the surface. A light beam 502 is emitted by the light emitting means to the charged surface on the downstream side in the rotation direction of the photosensitive drum 500 with respect to the contact position of the charging roller 501. The light emitting means includes a semiconductor laser 503 that emits a light beam 502,
Collimator lens 50 that polarizes a semiconductor laser into parallel light
4, a polygon mirror 505 for scanning the light beam 502 on the surface of the photosensitive drum 500, and a light beam 50.
2 is formed from an optical lens 506 that adjusts so as to form a spot on the surface, and an electrostatic latent image is formed on the surface of the photosensitive drum 500 by irradiating a light beam 502 based on image data. Excuse me. This electrostatic latent image is developed as a toner image by the developing device 507 arranged so as to contact the photosensitive drum 500 on the downstream side of the irradiation position of the light beam 502 in the rotation direction of the photosensitive drum 500. This toner image is formed on the photosensitive drum 500.
The image is transferred onto the recording paper P, which is a transfer material, by a transfer roller 508 which is disposed below the photosensitive drum 500 so as to face the photosensitive drum 500. The recording paper P is stored in the recording paper cassette 509 on the upstream side (right side in FIG. 8) of the photosensitive drum 500, but can be fed by hand. A paper feed roller 510 is provided at the end of the recording paper cassette 509, and feeds the recording paper P in the recording paper cassette 509 to the transport path. In the conveyance path between the paper feed roller 510 and the transfer roller 508, skew feeding of the recording paper P and the photosensitive drum 50 are corrected.
A registration roller 511 for synchronizing the image formation on 0 and the recording paper conveyance is recorded, and the recording paper P is fed to the above-mentioned transfer position at a predetermined timing.

A registration sheet presence / absence detecting sensor 512 is arranged between the registration roller 511 and the sheet feeding roller 510 to detect the presence / absence of the recording sheet P.

As described above, the recording paper P on which the unfixed toner image is transferred is further conveyed to the fixing position on the downstream side (left side in FIG. 8) of the photosensitive drum 500. The fixing device is composed of a fixing roller 513 having a halogen heater (not shown) inside, and a pressure roller 514 arranged so as to come into pressure contact with the fixing roller 513, and the recording medium conveyed from the transfer section. The paper P is fixed on the fixing roller 51.
The unfixed toner image is fixed on the recording paper P by heating while applying pressure at the pressure contact portion between the pressure roller 3 and the pressure roller 514. A discharged paper presence / absence detection sensor 515 for confirming that the recording paper P is discharged from the pressure contact portion is disposed downstream of the pressure contact portion. Further, a paper discharge roller 516 is arranged on the downstream side of the discharged paper presence / absence detection sensor 515 to discharge the fixed recording paper P.

When a double-sided printing instruction is issued from a host computer or the like (not shown) connected to the image recording apparatus, the recording paper P printed on one side by the reverse flapper 518 is conveyed into the double-sided unit 51. To be done. After detecting that the trailing edge of the recording paper P conveyed into the duplex unit 51 has passed the reversing sensor 519, the reversing roller 52
0 is reversely rotated, the recording paper P is conveyed to the double-sided paper feed sensor 522 by the conveyance roller 521, and the reversing operation is completed.
When the reversed recording paper P reaches the double-sided paper feed sensor 522, the conveyance is temporarily stopped, and after a predetermined timing, the above-mentioned one-sided printing operation is performed on the other surface to complete the double-sided printing.

In such a series of image forming operations, the fan motor 517 for the image forming apparatus is operated until a print instruction is given from a host computer (not shown) connected to the image recording apparatus, that is, in a standby state. It was rotated at a low speed, and the rise in the temperature inside the machine due to the low-voltage power supply (not shown), halogen heater, etc. was suppressed. In addition, when a print instruction is issued from the host computer or the like, the fan motor 517 for the image forming apparatus is immediately rotated at a high speed to reduce an increase in the temperature inside the apparatus caused by the image forming operation. further,
When the double-sided unit device 51 is mounted on the image forming apparatus 50, the fan motor 523 for the double-sided unit is constantly rotated to increase the temperature inside the machine due to the mounting of the double-sided unit device 51, and the fixing roller during the double-sided printing operation. 513
The increase in the temperature inside the machine due to the recording paper after the one-sided printing which was heated in the above was suppressed.

[0011]

However, the above-mentioned conventional example has the following problems.

The fan motor for the double-sided unit device is constantly driven regardless of the state of the device, and in a device in which the temperature inside the machine is not so high, the fan motor for the image forming device is installed even when the double-sided unit device is mounted. Since the fan motor for the double-sided unit device was driven together, the temperature inside the machine was reduced more than necessary, and extra power was consumed.

Therefore, an object of the present invention is to provide an image forming apparatus that solves the above problems.

[0014]

According to a first aspect of the present invention, there is provided a cooling first fan motor in a main body, and a cooling second fan motor is provided, and recording is performed after single-sided image fixing at the time of double-sided image formation. In the image forming apparatus in which the double-sided unit device for re-conveying the paper to the fixing device side is detachable from the main body, the first fan motor or the second fan motor is driven or stopped in response to a predetermined condition. It is characterized by comprising a control means for controlling.

According to a second aspect of the present invention, in the first aspect, there is provided a reversing flapper that guides the recording paper after the one-sided image is fixed into the two-sided unit device at the time of forming the two-sided image, and the control means includes the reversing flapper. The second unit in the double-sided unit device when continuously driven a predetermined number of times.
The fan motor is driven at a predetermined speed.

According to a third aspect of the present invention, in the first aspect, there is provided a reversing roller for reversing the front and back sides of the recording sheet guided in the double-sided unit device, and the control means has the reversing roller a predetermined number of times. Only when continuously driven, the second fan motor in the double-sided unit device is started to be driven at a predetermined speed.

According to a fourth aspect of the present invention, in the first aspect, the control means is configured to control the first unit for the image forming apparatus when the double-sided unit device is mounted on the image forming apparatus.
The feature is that the fan motor is stopped.

[0018]

【Example】

(Embodiment 1) First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 to 3.

FIG. 1 is a circuit diagram showing an example of a voltage supply circuit for a fan motor. Both the fan motor for a double-sided unit device and the fan motor for an image forming apparatus are formed by the same circuit, and are capable of high speed rotation, low speed rotation and stop. Control can be performed in each of the control units of the duplex unit device and the image forming apparatus in three modes.

The operation of the circuit shown in FIG. 1 will be described below.

In FIG. 1, reference numeral 100 denotes a control unit of the duplex unit apparatus and the image forming apparatus, which controls the rotation speed of the fan motor in three ways by the output signals from the two ports A and B. The control unit controls all operations of the duplex unit and the image forming apparatus, and includes a CPU.
And a memory such as a ROM that stores the control procedure of the CPU as shown in FIGS. 2 to 7, a memory such as a RAM having a work area for the CPU, and a non-volatile memory.

When the outputs of the ports A and B of the control unit 100 are both at high level, 101, 102, 103, 1
All the transistors 04 are turned on, Vcc is supplied as the power source of the fan motor, and the fan motor rotates at high speed.

When the output of the port A is at the high level and the output of the port B is at the low level, the transistors 101 and 102 are turned on, and Vcc is also supplied as the power source of the fan motor at this time, and the fan motor rotates at high speed.

When the output of the port A is low level and the output of the port B is high level, the transistors 103 and 104 are turned on, and the voltage obtained by subtracting the Zener voltage of the Zener diode 105 from Vcc is supplied as the power source of the fan motor. , The fan motor rotates at low speed. The number of rotations during the low speed rotation can be arbitrarily adjusted by changing the Zener voltage of the Zener diode 105.

When the outputs of the ports A and B are both at the low level, the transistors 101, 102, 103 and 104 are all turned off and the fan motor is stopped because no voltage is supplied to the fan motor.

Next, how to control the fan motor by using the fan motor drive circuit described so far,
This will be described with reference to the flowcharts of FIGS. 2 and 3.

In step 201, it is judged whether or not the duplex unit is mounted in the image forming apparatus, based on a signal from the sensor 106 for detecting the mounting of the duplex unit provided in the image forming apparatus. Then, it is determined whether or not it is in standby. During standby, the fan motor for the image forming apparatus is stopped (S203), and the fan motor drive routine is exited. Here, in a model in which the temperature rise inside the machine during standby is severe, in step 203, the fan motor for the image forming apparatus may be rotated at a low speed.

When the determination in step 202 is NO, that is, when the printing is in progress, it is determined in step 204 whether continuous printing is in progress. When the determination is NO, the fan motor for the image forming apparatus is rotated at a low speed, single printing,
The temperature rise in the machine caused by the intermittent printing state or the like is reduced (S205).

When the determination in step 204 is YES, that is, in the case of continuous printing, the image forming apparatus fan motor is rotated at high speed (S206), and after waiting until the printing is completed (S207), the image forming apparatus fan is rotated. The motor is stopped (S208), and the fan motor drive routine ends.

When the determination in step 201 is YES, that is, when the duplex unit is attached to the image forming apparatus, it is determined in step 209 whether or not it is in standby. When the determination in step 209 is YES, the fan motor for the image forming apparatus is rotated at a low speed (S210), and the fan motor drive routine is exited.

When the determination in step 209 is NO, that is, during printing, the image forming apparatus fan motor is rotated at high speed (S211). At this time, if the fan motor for the image forming apparatus cannot cool the internal temperature rise,
The fan motor for the duplex unit may be rotated at a low speed. Next, in step 212, it is determined whether or not continuous screen printing is performed. Step 21 if not continuous two-sided printing
In step 8, the image forming apparatus fan motor is stopped until printing is completed (S219), and then the fan motor drive routine is exited.

When the determination in step 212 is YES, that is, in the case of continuous double-sided printing, the number of times the reverse flapper has been driven, which was previously stored in the non-volatile memory in the control unit in step 213, is stored in the A register in the control unit. The number of times the reversal flapper is driven is the number of times that the fan motor for the double-sided unit device needs to be cooled because the temperature rise inside the machine becomes severe when continuous double-sided printing is performed over this number.

Next, at step 214, the reverse flapper is set to O.
When it is turned on, it is determined whether it is N or not, and when it is turned on, the content of the B register in the control unit is incremented by 1 (S215). Then, it is judged whether or not the content of the B register is larger than the content of the A register (S216), and if it is larger, the fan motor for the duplex unit is rotated at high speed (S217).

Next, in step 218, it is judged whether or not the continuous double-sided printing has been completed, and until the printing is completed, S2
The operations of 14 to S217 are repeated. When the continuous double-sided printing is completed, the fan motor for the image forming apparatus and the fan motor for the double-sided unit apparatus are stopped (S219), and the fan motor drive routine is exited.

As described above, by controlling the speeds of the fan motor for the image forming apparatus and the fan motor for the double-sided unit apparatus depending on the states of standby, single-sided continuous printing, double-sided continuous printing, etc., especially double-sided continuous printing. At the time of printing, the fan motor for the double-sided unit device is started to be driven when the predetermined number of continuous double-sided prints has been reached, so that the fan motor can be efficiently controlled.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment, the number of prints at the time of continuous double-sided printing is counted by using the number of times the reverse flapper is driven, but in the present embodiment, it is controlled by using the number of times the reverse roller is driven.

In step 313, the number of times the reversing roller is driven, which is stored in advance in the non-volatile memory, is stored in the A register in the controller. Similar to the first embodiment, the number of times the reversing roller is driven is the number of times in which the temperature inside the machine becomes severe when continuous printing is performed on both sides more than this number of times, and the fan motor for the double-sided unit device needs to be cooled. Then, in step 314, it is determined whether or not the reversing roller has been driven. The following control is the same as that of the first embodiment.

As described above, by counting the number of times the parts are driven only during double-sided printing, the number of double-sided prints can be known and efficient fan motor control can be performed.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the first and second embodiments, the case where the internal temperature of the image forming apparatus is increased by mounting the double-sided unit device has been described as an example. However, in the present embodiments, the printing like the on-demand fixing is performed. An example will be described in which the temperature rise becomes severe only occasionally.

It is judged whether or not it is in the standby state with the double-sided unit device attached (S209), and if it is in the standby state, the fan motor drive routine is exited.

If step 209 is NO, that is, if printing is in progress, the double-sided device fan motor starts to rotate at low speed (S411). Then, when printing is completed, the fan motor for the duplex unit is stopped (S41).
9).

As described above, when the temperature rise in the machine is not so severe, the cooling of the image forming apparatus side is covered by the fan motor for the double-sided unit when the double-sided unit is mounted, so that it is efficient. The fan motor can be controlled.

[0045]

As described above, according to the present invention,
For example, by controlling the fan motor for the image forming apparatus and the fan motor for the double-sided unit in high speed rotation, low speed rotation, and stop states in response to predetermined conditions such as standby, single-sided continuous printing, and double-sided continuous printing, it is unnecessary. It is possible to control the fan motor with an optimum drive current that does not consume a large current.

[Brief description of drawings]

FIG. 1 is a diagram showing a drive circuit of a fan motor according to the present invention.

FIG. 2 is a flowchart showing a part of the first embodiment of the present invention.

FIG. 3 is a flowchart showing another part of the first embodiment.

FIG. 4 is a flowchart showing a part of a second embodiment of the present invention.

FIG. 5 is a flowchart showing another part of the second embodiment.

FIG. 6 is a flowchart showing a part of a third embodiment of the present invention.

FIG. 7 is a flowchart showing another part of the third embodiment.

FIG. 8 is a diagram illustrating a conventional image forming apparatus.

[Explanation of symbols]

 100 control part 101-104 transistor 106 sensor

Claims (4)

[Claims] 1. A first fan motor for cooling is provided in the main body, and a second fan motor for cooling is provided to allow the recording paper after the single-sided image is fixed to be conveyed again to the fixing device side during double-sided image formation. In the image forming apparatus in which the double-sided unit device is attachable to and detachable from the main body, a control unit that controls the first fan motor or the second fan motor to be driven or stopped in response to a predetermined condition is provided. Image forming apparatus. 2. The reversing flapper according to claim 1, wherein the reversing flapper guides the recording paper after the single-sided image fixing into the double-sided unit device during double-sided image formation, and the control means sets the reversing flapper a predetermined number of times. The image forming apparatus is characterized in that the second fan motor in the double-sided unit device is started to be driven at a predetermined speed when only continuously driven. 3. The reversing roller according to claim 1, further comprising a reversing roller for reversing the front and back sides of the recording paper guided in the double-sided unit device, wherein the control means continuously drives the reversing roller a predetermined number of times. In the image forming apparatus, the second fan motor in the double-sided unit device is started to be driven at a predetermined speed. 4. The image according to claim 1, wherein the control means stops the first fan motor for the image forming apparatus when the duplex unit is attached to the image forming apparatus. Forming equipment.