JPH05289446A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device that a problem does not occur even when clothing is carelessly brought into contact with respective rotating bodies by enabling motors for respective drums to be rapidly stopped when the door of the image forming device main body is opened. CONSTITUTION:In the image forming device of such constitution that the photosensitive drum 1, the intermediate transfer drum 2 and the pressure drum 3 are driven to be rotated by mutually being pressured by the respective drums, the motors for driving drums which are rapidly stopped when the door provided on the image forming device main body 10 to be freely openable and closable, is opened, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is of a type in which a toner image on a toner image holding rotating body is primarily transferred to an intermediate transfer rotating body, and the transferred toner image on the intermediate transfer rotating body is secondarily transferred to a recording medium. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer or a facsimile, an electrostatic latent image is formed on a photosensitive member, and the electrostatic latent image is visualized as a toner image. It is transferred to a recording medium such as transfer paper by some method.

Generally, such transfer is carried out by a corona charger, but in the case of such a transfer means, the toner of the toner image scatters at the time of corona discharge, and is compared with the toner image on the photoreceptor. Then, the image obtained on the recording medium is likely to deteriorate.

Therefore, an image forming apparatus using an adhesive transfer method, which is a modification of the transfer method, has been proposed. The image forming apparatus of this example primarily transfers a toner image on a toner image holding rotating body such as a photosensitive drum to an intermediate transfer rotating body having viscoelasticity, and transfers the primary transferred image on the intermediate transfer rotating body. The image is secondarily transferred to a recording medium on a pressure rotating body.

In this type of image forming apparatus, since there is no toner scattering, a high quality image can be obtained. However, in this type of image forming apparatus, in order to effectively perform primary transfer (adhesive transfer) and secondary transfer, a relatively large pressure (for example, a pressure of about several kg / cm) is applied between the rotating bodies. It is necessary to hang it, and when configured in this way, so that clothes etc. are not caught between rotating rotating bodies,
It is necessary to take measures.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to allow a motor for driving each rotating body to be quickly stopped when the door of the main body of the image forming apparatus is opened so that clothes or the like are sandwiched between the rotating bodies. An object of the present invention is to provide an image forming apparatus that does not operate.

Still another object of each invention is to prevent the clothes and the like from touching the rotating body by locking the door of the image forming apparatus main body when the rotating body is in a driving state. It is to provide a forming apparatus.

[0008]

In order to achieve the above-mentioned object, the present invention rotates a toner image holding rotary member on the outer peripheral surface of which a toner image is formed, and a pressure contact with the toner image holding rotary member. In between, the intermediate transfer rotator to which the toner image on the toner image holding rotator is transferred and the toner image on the intermediate transfer rotator are transferred to the recording medium on the outer peripheral surface. A pressure rotating body that rotates by being pressed against a rotating body, a motor for driving the rotation of each of the rotating bodies, a door that can be opened and closed with respect to the main body of the image forming apparatus, and a door open detection that detects opening of the door. Means, and with the output of the door open detection means, with the output of the shutoff means for shutting off the drive current to the motor, and the door open detection means,
The present invention proposes an image forming apparatus provided with a short-circuit means for short-circuiting the drive lead wire of the motor.

Further, in order to achieve the above-mentioned object, the present invention provides a toner image holding rotating body on the outer peripheral surface of which a toner image is formed, and a rotation while being pressed against the toner image holding rotating body. The intermediate transfer rotator, to which the toner image on the toner image holding rotator is transferred, and the recording medium to the intermediate transfer rotator, so that the toner image on the intermediate transfer rotator is transferred to the recording medium, on the outer peripheral surface. A pressure rotating body that rotates while being pressed against each other, a rotation detecting unit that detects that each rotating body is rotating, a door that can be opened and closed with respect to the image forming apparatus main body, a lock of the door, and the lock. The invention proposes an image forming apparatus provided with door lock means for selectively unlocking the door and means for holding the door lock means in a locked state when the rotation detecting means detects the rotation of each rotating body. Is.

Further, in order to achieve the above-mentioned object, the present invention further comprises: a toner image holding rotating body on the outer peripheral surface of which a toner image is formed, and a rotation while being pressed against the toner image holding rotating body. The intermediate transfer rotator, to which the toner image on the toner image holding rotator is transferred, and the recording medium to the intermediate transfer rotator, so that the toner image on the intermediate transfer rotator is transferred to the recording medium, on the outer peripheral surface. A pressure rotating body that rotates while being pressed against each other, a signal output unit that outputs a signal that rotationally drives each rotating body, a door that is openably and closably attached to the image forming apparatus main body, a lock of this door, and a lock of the lock. The present invention proposes an image forming apparatus provided with door lock means for selectively releasing the lock and means for holding the door lock means in a locked state when the signal output means outputs a signal.

Incidentally, it is effective to provide a display section for displaying that the door is in the locked state by the rotation detecting means.

Further, it is effective that the rotation detecting means is composed of an encoder plate which rotates with the rotation of each rotating body, and a photo interrupter which is used in combination with the encoder plate.

Further, it is effective that the signal output means is provided with a display portion for displaying that the door is in the locked state.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a schematic structure of an image forming apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a photosensitive drum, which constitutes one example of a toner image holding rotator for forming a toner image on the outer peripheral surface, and is rotatably supported by a face plate 8 and is shown by an arrow in the drawing. It is designed to be rotated in the direction. With the start of rotation of the photosensitive drum 1, first, the surface of the photosensitive drum 1 is uniformly charged by the charging charger (scorotron charger) 4. At this time, the potential of the surface of the photosensitive drum is −800V, for example.

Reference numeral 5 denotes an optical writing device, which emits a laser beam 6 modulated according to image data, and this beam is emitted from the photosensitive drum 1.
By being incident on the surface of the photoconductor, optical writing is performed on the uniformly charged surface of the photoconductor, and a predetermined electrostatic latent image is formed on the surface. This electrostatic latent image is visualized as a toner image by the developing device 7. Reference numeral 5a is a polygon mirror for deflecting the laser light emitted from the semiconductor laser of the optical writing device 5, and reference numeral 5b is an fθ lens.

Reference numeral 2 denotes an intermediate transfer drum, which is an example of the structure of the intermediate transfer rotator, and the outer peripheral surface of the intermediate transfer drum exhibits releasability when heated and exhibits tackiness at room temperature. It consists of a body. For example, a sheet-shaped product of such silicone rubber is wound around the intermediate transfer drum body. Intermediate transfer drum 2
Is pressed against the photosensitive drum 1 with an appropriate force and is rotationally driven in the direction of the arrow in the figure. A heater 12 for heating the surface of the intermediate transfer drum 2 is opposed to the intermediate transfer drum 2 along the axial direction. Between the photosensitive drum 1 and the intermediate transfer drum 2, for example, 0.3 to 3.0 kg
/ cm pressure is applied.

When the photosensitive drum 1 and the intermediate transfer drum 2 are pressed against each other and rotate in the directions of the arrows,
The toner image on the photosensitive drum 1 is primarily transferred to the outer peripheral surface of the intermediate transfer drum 2 by the adhesive force of the outer peripheral surface of the intermediate transfer drum, for example, the adhesive force of the silicone rubber. At this time, a transfer bias is applied to the conductive layer of the intermediate transfer drum 2 to form an electric field in the nip (contact portion) between the photosensitive drum 1 and the intermediate transfer drum 2, and the action of the electric field also causes the photosensitive drum 1 to move on the photosensitive drum 1. Can be transferred to the intermediate transfer drum 2. In this case, the toner image on the photosensitive drum 1 is transferred to the intermediate transfer drum 2 due to both the adhesiveness of the outer peripheral surface of the intermediate transfer drum and the transfer electric field. It is primarily transferred to the surface. It is desirable that the bias voltage applied to the intermediate transfer drum 2 can be changed, for example, in the range of 500 V to 5 KV, and the bias voltage having a value suitable for various conditions is applied.

At the contact portion between the photosensitive drum 1 and the intermediate transfer drum 2, the toner is sandwiched between the two and hardly moves.
Due to the electrostatic force due to the electric field that is formed and the adhesive force from the intermediate transfer drum 2, the adhesive force with the intermediate transfer drum increases, and the adhesive force moves to the intermediate transfer drum 2 with almost no movement toward the photosensitive drum.

The toner image transferred onto the surface of the intermediate transfer drum 2 moves as the drum 2 rotates and is heated by a heater 12 composed of an infrared lamp or the like, so that the toner of the toner image is in a semi-melted state. It Below the intermediate transfer drum 2, a pressure drum 3, which is a configuration example of a pressure rotating body, is provided so as to be in contact with the intermediate transfer drum 2. A recording medium, which is the transfer medium 15 in this example, sent from the paper feeding unit 14 is wound around the pressure drum 3. The pressure drum 3 is provided with a clamp member 16 that is driven to open and close. The transfer paper 15 delivered from the paper supply unit 14 reaches the portion of the registration roller pair 34, and here, at a predetermined timing, the transfer drum 15 is pressed.
Sent to.

The transfer paper 15 is wound around the pressure drum 3 while the front end of the transfer paper 15 is clamped by the clamp member 16. In this state, the pressure drum 3
Is pressed against the intermediate transfer drum 2 and is rotationally driven in the direction of the arrow in the figure. In this way, the pressure drum 3
The upper transfer paper 15 is conveyed according to the position of the toner image on the intermediate transfer drum, and the intermediate transfer drum 2 and the pressure drum 3 sandwich the transfer paper, for example, 0.3 to 3.0 kg / cm.
Press with the pressure of.

The pressure drum 3 is provided along this axial direction.
A heater 13 such as an infrared lamp for heating the transfer paper on the pressure drum is provided oppositely. As described above, when the toners of the toner image on the intermediate transfer drum 2 are in a semi-molten state and are united with each other, the melted toner is transferred to the transfer paper on the pressure drum 3 heated by the heater 13. It undergoes a flow transition and the semi-molten toner infiltrates the fibers of the paper. That is, the secondary transfer is performed. Since the outer peripheral surface of the intermediate transfer drum 2 is heated by the heater and exhibits releasability, the secondary transfer of the toner image is reliably performed, and the transfer image on the transfer paper is retransferred onto the intermediate transfer drum 2. There is no such thing. The so-called offset prevention function is achieved. The tip of the transfer paper on the pressure drum 3 after the secondary transfer is removed from the previous clamp member 16, passes through the fixing roller pair 35, and is accommodated in the paper discharge tray 17. It The surface of the photosensitive drum 1 after the primary transfer is cleaned by the cleaning device 9.

Further, the surface portion of the intermediate transfer drum 2 after the secondary transfer is brought into pressure contact with the photosensitive drum 1 again and the drum 1 is transferred.
The toner image is primarily transferred from the intermediate transfer medium, but at this time, the intermediate transfer medium portion has already cooled and has returned to room temperature or a temperature close to it, so that it exhibits adhesiveness and is transferred from the photosensitive drum 1 to the intermediate transfer medium 10. The toner image is reliably transferred. Further, as indicated by an arrow A, for example, cool air may be blown into the area in the vicinity of the primary transfer portion to cool the outer peripheral surface portion of the intermediate transfer drum, and this may be more reliably returned to room temperature or a temperature close thereto.

In the single-color image forming mode, the pressure drum 3 makes one rotation to complete the image transfer. After this, the transfer paper on the pressure drum 3 is removed from this drum. After passing through the fixing roller pair 35, the sheet is discharged as a monochrome copy sheet onto the sheet discharge tray 17. In this mode, the transfer paper is not wound around the drum 3, but the transfer paper is fed from the paper feeding unit 14 by the registration roller pair 34 at a timing, and the transfer paper is fed between the drums 2 and 3. A predetermined monochrome image can be obtained only by passing through.

Although not shown, the developing device 7 is equipped with a yellow developing device, a magenta developing device, a cyan developing device, a black developing device, etc., and in the case of a color image forming mode, a photoconductor Each time the drum 1 rotates, a toner image having a different color is formed on the surface thereof, and the intermediate transfer drum 2
The toner images of the respective colors that have been transferred to are transferred and superposed on the same position of the transfer paper wound around the pressure drum 3. Four
Primary transfer of color toner images onto the intermediate transfer drum 2 in sequence,
It is also possible to secondarily transfer this onto the transfer paper 15 at once.

After the transfer of the four color toner images is completed,
The transfer paper is removed from the pressure drum 3, and the fixing roller pair 35
After passing through, the color copy paper is ejected to the paper ejection tray 17.

The developing bias applied to the developing sleeve (not shown) of each developing unit is set to -600 V, for example.
The electrostatic latent image is visualized by reversal development. That is, the toner adheres to the low potential portion of the photosensitive drum 1,
The high potential portion becomes a background portion, and the toner adheres to the intermediate potential portion at a density corresponding to it.

A jam detection sensor 36 is provided on the entrance side of the registration roller pair 34, and this sensor allows
The jammed state of the transfer paper 15 from the paper supply unit 14 toward the pressure drum 3 is detected. A jam detection sensor 37 is also provided on the exit side of the fixing roller pair 35, and this sensor detects a jam of the transfer paper before and after the fixing roller pair 35.

The signal of the jam detection sensor is taken into the CPU and it is checked whether this signal is longer than usual. For example, in the color image formation mode,
Even when the transfer paper released from the clamp member 16 should of course enter the fixing roller pair 35, if the transfer paper is not detected, the CPU determines from this signal that a jam has occurred, and the intermediate transfer drum 2 and Crimping with the pressure drum 3 is released so that the jammed paper can be easily taken out. In this apparatus, at the same time, the lamp for the fixing roller is turned off so that the heat of the lamp is not directly applied to the transfer paper. Further, at the same time, a fan for cooling the inside is rotated, thereby rapidly cooling the jammed paper and making it easy to take out the jammed paper.

In addition, the intermediate transfer drum 2 is rotatably mounted on a pair of levers 19 pivotally mounted on a side plate (not shown) by a shaft 18, and the force of a spring 20 applied to the levers 19 causes the photosensitive member to be rotated. The drum 1 is brought into pressure contact with an appropriate nip pressure.

Further, another pair of levers 22 is pivotally attached to the lever 19 by a shaft 21.
The pressure drum 3, which is rotatably mounted on the
The force of a spring 23 interposed between the rollers 9 and 22 presses the intermediate transfer drum 2.

In such an image forming apparatus, in order to remove a transfer sheet having a jam inside, or to supply toner to a toner hopper inside the image forming apparatus, the entire apparatus is usually used. There is a door that spans over or is divided into several parts.

In FIG. 4, reference numeral 25 is such a door, which is provided so as to be openable and closable with respect to the image forming apparatus main body 10. In the door 25 of this example, the H part is
It is a hinge part for opening and closing.

In the case where the door 25 is a front door facing the operator, when the user grasps the grip 25a and pulls the door 25, the door 25 is opened as shown in FIG.
The inside of the device on the front side is exposed.

When such a door 25 is opened carelessly, if the drums 1, 2 and 3 are still rotated, relatively strong pressure is applied to them, so that clothes etc. May be sandwiched between them.

Conventionally, in such an image forming apparatus, generally, the opening of the door is detected, and based on this detection, the CPU is detected.
The motor for driving the rotation of each drum is stopped, or the power source of the motor is directly turned off, or the main power source itself is turned off, to stop the motor.

However, in the case of the image forming apparatus as shown in FIG. 1, since each drum is rotated by applying pressure, the main power source capacity becomes large, and
Each drum does not stop immediately due to the influence of the motor itself and the rotational inertia of the rotating load system, etc. due to the increase in the operating speed of the device, etc. May be touched.

The present invention solves such a problem.

A reference numeral 26 in FIG. 4 denotes a door open detection switch provided on the image forming apparatus main body 10 side. The door open detection switch 26 detects the open state of the door 25. That is, the door open detection switch 26 is turned off when the door 25 is opened and turned on when the door is closed, and the open state of the door 25 is detected by the difference between on and off. Of. The door open detection switch 26 constitutes one configuration example of door open detection means.

FIG. 2 shows an example of a drive circuit configuration of a motor 27 for rotationally driving each of the drums 1 to 3. Normally, the motor 27 is rotationally driven in the operating state of this figure. ..

In such an operating state, as shown in FIG.
When the door 25 is opened, the door open detection switch 26 is turned off. The signal X (FIG. 2) is turned off by the operation of the door open detection switch 26. This is 2
It is a power supply line of 4V, which cuts off 24V supplied to the relay RL, so that the relay RL is turned off and the connection state of the circuit is changed as shown in FIG. That is, the switch 26 is turned off as shown in FIG. 3, and along with this, the power supply to the relay RL is cut off, and the switch contact in the relay, which is as shown in FIG. 2, is set as shown in FIG. It switches. The switching of the contacts cuts off the drive current to the motor 27.

At the same time, the periphery of the drive coil on the motor 27 side is short-circuited, and the drive lead wire 28 of the motor is short-circuited. The relay RL has a function as a cutoff unit that cuts off the drive current to the motor according to the output of the door open detection unit, and a function as a short circuit unit that short-circuits the drive lead wire of the motor according to the output of the door open detection unit. Will be fulfilled together.

When the relay RL is brought into the contact state as shown in FIG. 3, the drive lead wire 28 is short-circuited as described above.
The motor 27 will act as a so-called generator. That is, the rotation of each drum (rotation due to inertia) causes a back electromotive force in the motor coil 33, and the motor 27 is stopped rapidly.

Along with the rapid stop of the motor 27, the drums 1 to 3 also stop rapidly. When the door 25 (Fig. 4) is opened, such a quick stop will be immediately performed.
Very safe.

Next, another invention will be described.

The image forming apparatus according to the embodiment of the present invention is
In addition to the drums 1 to 3 and the door 25 described above, a rotation detection unit that detects that each drum is rotating, a door lock unit, and a rotation of each drum are detected.
It is provided with means for holding the door lock means in a locked state.

Now, the rotation detecting means will be described. The rotation detecting means of this embodiment includes the drums 1, 2, 3
It is composed of an encoder plate that rotates in accordance with the rotation of, and a photo interrupter used in combination with the encoder plate.

That is, as shown in FIG. 6, each drum 1
3 to 3 are rotatably driven by the driving force of the motor 27 via the rotation transmission mechanism 29 by a gear system. Among the drums rotatably driven, for example, the intermediate transfer drum 2 is used. As shown in FIG. 7, an encoder plate 31 in which a large number of holes are formed is integrally fixed to the shaft 2A of the shaft 2, and the rotation of each drum is detected by using the encoder plate 31 and the photo interrupter 32 together. Is done. In this case, of course, the rotation speed of each drum can also be detected.

As the drums 1, 2 and 3 rotate, the photo interrupter 32 outputs a signal having a waveform as shown in FIG. 8. By detecting this signal, the drum rotates. Whether or not it can be detected. Note that the encoder plate 31 can achieve the same function even if it is attached to another drum shaft.

FIG. 5 shows a lock mechanism as an example of a door lock means for selectively locking and unlocking the door, and the lock mechanism is provided on the door 25 side. This mechanism includes a solenoid 38 and a pivot 3
It comprises a swing rod 40 having 9 as a fulcrum, lock rods 41 and 42 connected to the rod, respectively.

When the solenoid 38 is excited, the swing rod 4
0 turns counterclockwise around the fulcrum 39 and locks the rod 4
1, 42 move up and down, the tip of each lock rod,
The holes are inserted into the holes 44 and 45 of the image forming apparatus main body 10, respectively. As a result, the door 25 is locked so that it cannot be opened. On the other hand, when the solenoid 38 is de-excited, the force of the spring 43 returns the lock rods 41 and 42 to their original positions via the swing rod 40, and the locked state is released.

As described above, when the rotation of each drum is detected, that is, when the rotation signal of each drum is output as shown in FIG. 8, the solenoid 38 is operated.
Is always driven, which ensures that the locking operation is maintained by the above-mentioned locking means. In this way, the driving of the solenoid 38 coincides with the signal of the rotation detecting means, and the door 2 can be driven only while the drums 1, 2 and 3 are rotating.
5 is locked and opening of the door 25 is prohibited.

Regarding the means for holding the door lock means in the locked state when the rotation detecting means detects the rotation of the drums 1, 2, 3, there are also, for example, electric circuit processing means or mechanical means. It can be configured by any means. In any case, each drum 1-3
Since the door 25 cannot be opened during the rotation of
It's safe. That is, it is possible to prevent the door from being opened carelessly.

When the motor rotates to rotate each of the drums 1, 2, and 3, the encoder signal is generated and the pulse signal as shown in FIG. 8 is generated from the photo interrupter, as described above. However, this pulse signal is due to the retriggerable pulse generation circuit,
Therefore, while the pulse signal is being generated, the rotation signals of the drums 1, 2 and 3 are continuously being generated.

This signal causes the solenoid 38 (FIG. 5).
Is driven to lock the door 25. In this way, it is possible to prevent the door from being opened accidentally. Also, when a jam occurs,
It is safe in this case as well, as the door can only be opened after the rotation of each drum has stopped.

FIG. 9 is a control block diagram corresponding to the embodiment of the present invention, in which the rotation of the encoder plate is detected by the photo interrupter to generate the rotation signal of the drum.
The rotation detection signal drives the solenoid via the solenoid driver to lock the door.

Here, if the door 25 is provided with a display section for indicating that the door is in the locked state, "the door cannot be opened".
Message to the operator etc., and it is possible to avoid the useless act of opening the door.

The door 25 shown in FIG. 4 is provided with a display section 46 for displaying that the door is in a locked state. This display section 46 is provided by turning on a display lamp (not shown) inside the display window. , Illuminates the display window as a backlight and makes it red, for example, and at the same time the message "LOCK" is highlighted. That is, as shown in FIG. 9, the display lamp driver is driven by the display lamp driver in accordance with the detection of the rotation of the drum, the display lamp is turned on, and the display unit 46 is LOC.
The K display state is set. As described above, in this example, the rotation detecting unit serves as a display unit for displaying that the door is in the locked state. It is desirable to provide such a display portion as close to the handle portion 25a as possible, and if it is provided at such a position, it is possible to further reduce the possibility of performing the above-mentioned useless act.

Next, another invention will be described.

The image forming apparatus according to the embodiment of the present invention is
In addition to the above-mentioned drums, doors, door lock means, holding means for the lock means, and the like, signal output means for outputting a signal for rotationally driving each drum is provided.

FIG. 10 is a control block diagram corresponding to this embodiment, in which a drive signal SN of the drum drive motor is output from the CPU which is an example of the signal output means.
In this embodiment, the motor drive signal SN is used to hold the door lock means in the locked state. With such a system, a drum rotation detecting unit including an encoder plate, a photo interrupter, and the like, an electric circuit accompanying the unit, and the like are not required, and the image forming apparatus can be inexpensive.

Also in this embodiment, the door may be provided with the display portion 46 as shown in FIG.
The same effects as those of the above-described embodiment of the invention can be obtained. For example, as shown in FIG. 10, the display lamp is turned on via the display lamp driver in synchronization with the output of the motor drive signal SN from the CPU. In this way, the display unit 46 of this example displays that the door 25 is in the locked state by the signal output means.

It should be noted that any of the inventions can be applied to an image forming apparatus of a type in which a document image is image-projected onto a toner image holding rotating body such as a photosensitive drum.

[0064]

According to the first aspect of the present invention, the toner image holding rotary member, the intermediate transfer rotary member, and the pressure rotary member are provided.
In an image forming apparatus of a type in which rotating bodies are rotationally driven by applying pressure to each other, even if a door provided on the main body of the image forming apparatus is opened carelessly, each rotating body rapidly stops. So, in each of these rotating bodies,
Even if clothes touch it, there will be no problem.
In addition, no braking means or the like is required for stopping each rotating body driving motor rapidly.

According to the structure of claim 2, an image of a type in which the toner image holding rotary member, the intermediate transfer rotary member, and the pressing rotary member are rotationally driven by applying pressure to each other. In the forming device, when each rotating body is rotating,
Since the door provided to the image forming apparatus main body so as to be openable and closable is always locked so that it cannot be opened or closed, the rotating body or the like in the operating state is not exposed.

According to the third aspect of the present invention, the toner image holding rotary member, the intermediate transfer rotary member, and the pressure rotary member are rotationally driven by applying pressure to each other. In the forming device, when each rotating body is rotating,
Since the door provided to the image forming apparatus main body so as to be openable and closable is always locked so that it cannot be opened or closed, the rotating body or the like in the operating state is not exposed. Further, in the case of this configuration, there is no need for means for detecting rotation of the toner image holding rotating body, the intermediate transfer rotating body, the pressure rotating body, etc., and the image forming apparatus can be made more inexpensive. You can

According to the structure described in claim 4, it is possible to prevent the originally useless act of opening the door.

According to the fifth aspect of the invention, the rotation of the rotating body such as the toner image holding rotating body can be accurately detected with a simple configuration.

According to the sixth aspect of the invention, it is possible to prevent the originally unnecessary action of opening the door.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a drive control circuit of a drive motor for a photosensitive drum or the like which is provided in the image forming apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram showing that a drive control circuit of a drive motor for a photoconductor drum or the like provided in the image forming apparatus according to the exemplary embodiment of the present invention is in an off state.

FIG. 4 is a diagram showing a state in which a door provided to the image forming apparatus main body so as to be openable and closable is opened.

FIG. 5 is a diagram illustrating an example of a door lock mechanism that is provided in the image forming apparatus main body so as to be openable and closable.

FIG. 6 is a diagram showing an example of a drive mechanism for a rotating body such as a photosensitive drum.

FIG. 7 is a diagram showing an example of rotation detection means for a rotating body such as a photosensitive drum.

FIG. 8 is a diagram showing an output pulse waveform and the like by the rotation detecting means.

FIG. 9 is a control block diagram corresponding to another embodiment of the invention.

FIG. 10 is a control block diagram corresponding to another embodiment of the invention.

[Explanation of symbols]

 10 image forming apparatus main body 25 door 27 motor 28 drive lead wire 31 encoder plate 32 photo interrupter 46 display unit

Claims (6)

[Claims] 1. A toner image holding rotary member on which a toner image is formed on the outer peripheral surface, and a toner image on the toner image holding rotary member on the outer peripheral surface while rotating while being pressed against the toner image holding rotary member. An intermediate transfer rotator to which is transferred, a pressure rotator that rotates by contacting the recording medium with the intermediate transfer rotator so that the toner image on the intermediate transfer rotator is transferred to the recording medium, and A motor for rotationally driving each rotating body, a door that is openably and closably provided with respect to the image forming apparatus main body, a door open detection unit that detects opening of the door, and an output to the motor according to the output of the door open detection unit. With the output of the shut-off means for shutting off the drive current and the door open detection means,
An image forming apparatus comprising: a short-circuit means for short-circuiting a drive lead wire of the motor. 2. A toner image holding rotary member on which a toner image is formed on the outer peripheral surface, and a toner image on the toner image holding rotary member on the outer peripheral surface while rotating while being pressed against the toner image holding rotary member. An intermediate transfer rotator to which is transferred, and a pressure rotator that rotates by contacting the recording medium with the intermediate transfer rotator so that the toner image on the intermediate transfer rotator is transferred to the recording medium. A rotation detecting means for detecting that the rotating body is rotating; a door provided to be openable and closable with respect to the image forming apparatus main body; a door locking means for selectively locking and unlocking the door; An image forming apparatus comprising: means for holding the door lock means in a locked state when the rotation detecting means detects the rotation of each rotating body. 3. A toner image holding rotary member on which a toner image is formed on the outer peripheral surface, and a toner image on the toner image holding rotary member on the outer peripheral surface while rotating while being pressed against the toner image holding rotary member. An intermediate transfer rotator to which is transferred, and a pressure rotator that rotates by contacting the recording medium with the intermediate transfer rotator so that the toner image on the intermediate transfer rotator is transferred to the recording medium. A signal output means for outputting a signal for rotationally driving the rotating body; a door provided to be openable and closable with respect to the main body of the image forming apparatus; a door locking means for selectively locking and unlocking the door; An image forming apparatus comprising: a means for holding the door lock means in a locked state when the output means outputs a signal. 4. The image forming apparatus according to claim 2, further comprising a display unit that displays that the door is locked by the rotation detecting unit. 5. The image forming apparatus according to claim 2, wherein the rotation detecting means includes an encoder plate that rotates with the rotation of each rotating body, and a photo interrupter that is used in combination with the encoder plate. 6. The image forming apparatus according to claim 3, further comprising a display unit that displays that the door is locked by the signal output unit.