JPH0466352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electrophotographic copying machine that forms an image corresponding to a document image on a recording medium and transfers this image to a transfer member that is appropriately conveyed.

<Prior art> To briefly explain the operation of an electrostatic copying machine, it uses a photoreceptor, which is a recording medium, with a photoconductive layer formed on the top surface of a conductive layer, and the photoconductive layer of the photoreceptor is uniformly charged. I do. By exposing the photoconductive layer of the photoreceptor to a light image, an electrostatic latent image corresponding to the light image is formed on its surface. Thereafter, toner is applied to the electrostatic latent image in a developing section to make it into a visible image. Then, the plain paper being fed is brought into close contact with the photoreceptor, the toner image is transferred to the plain paper, the plain paper is sent to the fixing section, the transferred toner image is fixed, and the paper is sent out to the exit. ing.

The above is a general dry type copying machine. Here, the copying process, that is, charging, exposure, phenomenon, transfer,
Regarding the control of each process such as fixing, as mentioned earlier, microswitches etc. that detect the paper feeding state or the rotational position of the photoreceptor drum are appropriately placed in various places, and the operation state of these microswitches is used to control the Each control is performed.

In this case, the conventional control circuit is mainly complicated, and the wiring connecting the microswitch groups and the control circuit is required as many as the number of switch groups, and the arrangement of these switches is not constant, which increases the complexity. It was unavoidable.

If the control circuit is to connect a large number of TTL-ICs and perform charging, for example, depending on the operating state of the switch group, the control circuit outputs a charging unit control signal, and the charging unit is activated via the driver circuit. That's what I do.

It is very difficult to arrange the above-mentioned switch group in a fixed place because the switches are used as a detection means in terms of control or mechanism.

On the other hand, copying machines use the following means to convert each detection signal, that is, an electrical signal for control, into a mechanical output, including an output signal when a paper jam is detected.
A solenoid is used. The copying machine as a whole, including these solenoids, becomes a noise source for the electronic control circuit. Furthermore, it is clear that the complicated wiring and the fact that it requires a considerable line length make it susceptible to electronic noise sources. Moreover, the copying machine itself performs various operations in synchronization with the rotating photoreceptor drum.
For example, charging, exposure, and movement of the document table are performed, but the control circuit is controlled by operating status signals from a group of switches that enter asynchronously, so it is inherently weak in terms of noise resistance. It was hot.

From a time point of view, the control of a copying machine is sufficiently long, from when the print switch is pressed to when the copy is made and when the document table is returned to its original position, and the entire control time from when the print switch is pressed to when the document table is returned is long enough, and the detection of the switch groups can be performed in parallel as long as time allows. The operating status of these switch groups can be confirmed in series.
By performing this parallel control in series, unnecessary wiring can be omitted, and the above-mentioned effect of increasing the margin in noise resistance becomes greater.

To achieve this, for example, one chip,
ROM-RAM using MOS-FET in one package
There is a system that uses a microprocessor to control copying.

The above-mentioned microprocessor uses subdivided digital control and arithmetic circuits to communicate with read write memory (RAM) using instructions stored in read only memory (ROM). This is a processing device that operates including mutual transmission.

As mentioned earlier, the effective use of microprocessors in copying machines was briefly mentioned, but the control time of a series of copying machines was long enough to compensate for the disadvantages of processors in terms of processing time. It will be put to very good use.

In particular, by using MOS-FET, power consumption is significantly lower than that of TTL, and the degree of integration is also improved, so it can be used more efficiently.

In addition, by using a microprocessor to control the copying machine, the electronic control circuit can be significantly downsized.In other words, the conventional control circuit can be replaced with just one microprocessor, which greatly reduces the number of parts and improves reliability. In addition, serial control is performed to improve performance and durability, prevent the influence of external nozzles, and check various conditions of the copying machine, such as the detection status of a group of microswitches, thereby reducing interconnections. Furthermore, changes in peripheral devices and specifications expected in the future can be handled by modifying the ROM of the microprocessor itself, making it easy to make significant improvements compared to copiers using conventional control methods. The results are also great.

Irrespective of the control of the microprocessor mentioned above, the paper transport path that transports the paper to the transfer process, transfers the phenomenon to the paper, and then transports the paper to the fixing section, as described above, is provided. Micro-switches and the like for paper detection are arranged as appropriate.
This paper detection microswitch notifies the microprocessor of the paper transport status, and also
It is used to detect defects in the conveyance state of paper, that is, jams.

Therefore, if a paper jam occurs, the operation of the copying machine stops in that state. Then, when the jammed paper is removed and the jam is cleared, the power to the copying machine is turned on and the specifications of the copying machine can be adjusted. In this case, a portion of the jam paper often remains on the conveyance path within the copying machine. Therefore, the conveyance of the next sheet may be blocked by the remaining sheet, and jamming may occur again. Further, it is also possible that the remaining paper may cause problems in the image forming apparatus. Furthermore, if paper remains in the fixing unit, smoke or fire may occur.

Furthermore, the copying operation may stop for some reason other than jamming. For example, a copying operation is stopped midway due to a drop in power supply voltage or a stoppage of power supply due to a power outage or the like. In such cases, paper may become stuck in the transport path, and removal of this paper is often forgotten. This causes problems similar to those described above.

<Purpose> The purpose of the present invention is to ensure safe and reliable specifications of a copying machine.

In particular, it is an object of the present invention to determine whether or not a copying machine can be used based on detecting the presence or absence of paper in advance when the power is turned on.

<Embodiment> Hereinafter, jam detection during a copying operation according to the present invention will be described in detail.

First, the configuration of the copying machine according to the present invention will be explained. In FIG. 1, reference numeral 1 denotes a rotating drum that is rotated in the direction of the arrow at a constant speed around a shaft 2, and the drum 1 has a master paper, that is, a surface formed with a photoconductor, on its outer circumferential surface. A photoreceptor 3 whose back surface is made of a conductive layer is detachably attached. Although not shown, the photoreceptor 3 is fixed to the outer circumferential surface of the drum 1 by being held down by a presser claw attached to the circumferential surface of the rotating drum 1 at its leading end. When replacing the photoreceptor 3, the presser claw opens, the old photoreceptor is conveyed to the outside, that is, to the paper outlet 5, and a new photoreceptor 3 is inserted through the photoreceptor insertion port 4, and its tip is inserted into the presser claw. It is held down and fixed. This operation is automatically performed in conjunction with the rotation of the drum 1. A micro switch MS ₇ installed near the photoconductor insertion slot 4 detects the insertion of the photoconductor 3. When this switch MS ₇ is turned on, the photoconductor 3 replacement cycle begins. A body swap is performed. Regarding the automatic replacement of the photoreceptor 3,
This type of device has been developed in the past and is implemented by a known mechanism, so a description thereof will be omitted. Various devices are provided near the rotating drum 1 to form an image corresponding to a document on the surface of the photoreceptor 3. In the figure, reference numeral 6 denotes a charger for uniformly charging the surface of the photoreceptor 3. The charger 6 generates a high voltage by energizing a charging high voltage generating unit CHVU as shown in the circuit diagram of FIG. 2, and the surface of the photoreceptor 3 is uniformly charged by this high voltage. The energization at this time is carried out by energizing the charging relay and closing its contact CHVR-a.

Reference numeral 7 denotes an exposure section which irradiates the charged photoreceptor 3 with a light image to form an electrostatic latent image. This exposure is performed by illuminating the transparent glass surface of the document table 8 on which the copy document is placed using an illumination device 9, and transmitting the reflected light through an optical system 10.

Here, the document table 8 is configured to move in synchronization with the rotating drum 1. That is, the movement of the original platen 8 is started at the same time as the photoreceptor of the rotating drum 1 comes to the exposure section 7, and the moving speed at this time is naturally equal to the rotational speed (peripheral speed of the drum 1).

Reference numeral 11 denotes a developing device for visualizing the electrostatic latent image, which attaches toner to the area where the electrostatic latent image is formed to form a toner image.

Reference numeral 12 denotes a transfer charger for transferring the toner image onto the transfer paper 13. The transfer paper 13 is automatically fed by a paper feed roller 20, and the first roller 2
1, the paper is conveyed into the copying machine, and is fed through each roller in synchronization with the rotation of the rotating drum 1. Once the paper is fed, it is stopped by a paper stopper 14 provided at the paper input section. will be stopped. The micro switch MS ₁ installed in the paper input section detects the paper input status.
While MS ₁ is detecting paper input, rotating drum 1
When the transfer paper 13 rotates to a certain position, the stopper 14 opens and the transfer paper 13 is fed, synchronized with the rotating drum 1 at a good timing, and brought into close contact with the photoreceptor 3 on which the toner image is formed. And charger 1 for transfer
2, the toner image is transferred onto the transfer paper 13. Reference numeral 15 denotes a device for peeling off the transfer paper 13 from which the toner image has been transferred and in close contact with the photoreceptor 3 of the drum 1, and transporting the transfer paper 13.

When the transfer paper 13 is peeled off from the photoreceptor 3, it is attracted to a conveyor belt 15a by air suction force (direction indicated by an arrow) in a peeling device 15 and sent to the next process. A micro switch MS ₂ provided near the peeling device 15 detects when the transfer paper 13 is peeled off.

At this point, the toner image transferred to the transfer paper 13 is still in an unstable state and not completely fixed on the transfer paper 13, and it is necessary to fix the toner.
This is because the transfer paper 13 is conveyed by the conveyor belt 15a of the peeling device 15, sent to the fixing section 16,
The toner image is fixed.

The toner fixing section 16 is provided with a heater lamp HL serving as a heat source, and thermal fixing is performed using this heat source. Further, there is an optimum temperature range for toner fixing in the fixing section 16, and unless the temperature rises above this temperature, the copying operation will not be executed. The above temperature is about 300°C. Further, the transfer paper holder 17 of the fixing unit 16 is at the position shown by the solid line when the power is turned on, and at the position shown by the dotted line when the power is turned on. The micro switch _MS8 detects this state. For example, the fixing unit 16 moves this pedestal 17 as shown by the dotted line when power is no longer supplied.
When a jam occurs in the transfer paper, the power supply unit is opened. At this time, the power supply unit is opened to prevent the transfer paper 13 from catching fire in the fixing unit 16, and is kept away from the heater lamp HL, and the transfer paper 13 can be easily removed. I have to.

The transfer paper 13 conveyed within the fixing section 16 is conveyed out from the paper outlet 5 by the rotation of the conveyance roller 22. A micro switch MS ₃ installed near the paper output port 5 detects this paper output. Note that 23 is for detecting the slip roller jam, and roller 23a is a driving roller and 23b is a driven roller.If the transfer paper 13 is being conveyed normally, the rotation of the driving roller 23a is transmitted to the roller 23b. If the paper is not conveyed normally, for example if a jam occurs, the rotation will not be transmitted and the jam will be detected.

On the other hand, the reference numeral 18 in the figure is a static eliminator for removing static electricity from the transfer paper 13, and unlike the other chargers 6 and 12, the static electricity removal is performed by AC corona discharge. Also, although the photoreceptor 3 is not shown in the figure, the heater lamp HL
The charge is removed by the light beam from the cleaner brush 19.
The surface is cleaned and prepared for the next electrostatic latent image formation.

Here, the static eliminator 18 and the transfer charger 1
In both cases, when the high voltage generating unit THVU is energized, static electricity is removed by corona discharge and charging for transfer is performed.
The THVU is energized when the relay is turned on by a control signal from the control circuit and its contact THVR-a is closed.

Further, the document table 8 starts to move (feed) in synchronization with the movement of the rotary drum 1 to reach a predetermined rotational position, and returns to the original position when the movement exceeds a predetermined length (hereinafter referred to as overrun). controlled. Therefore, the initial stop position of the document table 8 is detected by the micro switch MS ₄ , which is provided opposite the actuating piece 8a that is interlocked with the movement of the document table 8, and the overrun of the document table 8 is detected by the micro switch MS4. Micro switch installed opposite to switch MS _4
MS5 .

The present invention is directed to the control of various mechanisms in the general copying machine constructed as described above, such as the drive of the rotary drum 1, the feed and return of the document table 8, the conveyance of transfer paper, the chargers 6 and 12, the static eliminator 18, etc. is controlled by a one-chip microprocessor. A series of operations of the copying machine configured as shown in FIG. 1 will be briefly explained.

First, when the power switch MSW is turned on, the main motor MM rotates. Also, power relay contacts
When PR-a and PR-b (see Figure 2) are closed, the heater lamps HL ₂ and HL ₃ are turned on to raise the temperature of the fixing section 16, and when the temperature reaches the specified temperature, a copy-ready message is displayed. be done. Therefore, when the print switch PSW is pressed, the rotating drum 1 rotates, and in synchronization with this, various mechanisms operate depending on the operating state of each microswitch. Therefore, when the rotating drum 1 reaches a certain position, the light source lamp of the lighting device 9
CL lights up, the surface of the photoreceptor 3 is charged by each charger, and the document table 8 starts moving. On the other hand, if the microswitch MS ₁ detects paper entry, the paper stopper 14 opens in synchronization with the rotation of the drum 1, and the transfer paper 13 is transported by the transport roller 21.

On the other hand, an electrostatic latent image is formed on the photoreceptor 3 in the exposure section 7, and this latent image becomes a toner image in the developing device 11 and is sent to the transfer section for the next step. The transfer paper 13 conveyed to the photoreceptor 3 is brought into close contact with the photoreceptor 3 in a well-timed manner, and the toner image is transferred onto the transfer paper 13 by the transfer charger 12. Thereafter, the transfer paper on which the toner image has been transferred is peeled off from the photoreceptor 3 of the drum 1, and in the peeling device 15, it is attracted to the conveyor belt 15a by air suction force, and the static electricity is removed by the static eliminator 18, and the heater lamp HL is removed. The image is transported to the built-in fixing unit 16. Then, the transfer paper 13 is transferred to the fixing section 1
6 and is transported to the outside from the paper output port 5 by the delivery roller 22.

As the drum 1 rotates, the surface of the photoreceptor 3 is neutralized by light beams from the heater lamp HL of the fixing section 16, and passes through a cleaner brush 19 to be neutralized and cleaned, and is ready for forming the next electrostatic latent image. Further, the document table 8 is in an overrun state, and when this state is detected by the micro switch MS ₅ and returned to the original stop position, the switch MS ₄ that detects this is activated and stops. Further, the rotating drum 1 also stops at the initial stop position. In this case, the number of copies is one, and in the case of multiple copies, the above-mentioned operation is repeated several times and the copying operation is stopped after a predetermined number of copies have been made. For example, when making multiple copies, a multi-copy dial is provided and the copying operation is stopped when this dial reaches 0.
The micro switch MS ₆ installed in the multi-copy dial section detects this.

Since the copying operation is performed as described above, the control of the present invention is performed by a microprocessor. FIG. 3 is a control block diagram of the copying machine according to the present invention. In FIG. 3, reference numeral 30 denotes a microprocessor (hereinafter referred to as a control element) consisting of one chip and one package, and a solenoid which operates a copying operation via a driver circuit 32 in response to a control signal 31 from this control element 30. Energizing relays, etc. (hereinafter, “ON” means when energized, “OFF” means when not energized)
be memorized as . )I do. For example, when the drum feed clutch DFC is turned on, the rotating drum 1 starts rotating. In order to control these various solenoids, relays, etc., a synchronization signal 33 for controlling the copying operation accompanying the rotation of the drum 1 is sent to the control element 30.
The synchronizing signal 33 is used to derive a signal 35 (hereinafter referred to as a strobe signal) from the control element 30 that confirms the detection state of the microswitch group 34 that detects the various copying operations described in FIG. By applying this strobe signal 35 to a group of switches, etc., and inputting its output to the control element 30, the current state of each microswitch can be confirmed. Confirmation status at this time and the above synchronization signal 33
In combination, the control signal 31 as described above is output from the control element 30 to control copying of the copying machine.

The synchronization signal 33 input to the control element 30 is
The signal is generated by the signal generating section 37 by the rotation of the rotary drum 1 corresponding to the travel of the photoreceptor 1. In other words, the synchronization signal generating section 37 includes a disk 24 shown in FIG. 4, which is provided on the same axis as the shaft 2 of the rotating drum 1 shown in FIG. ignition through the slits, respectively;
It is constructed by arranging a photoelectric exchange device consisting of a light receiving element. Therefore, the signal 3 synchronized with the rotation of the drum 1
3 is output from the synchronization signal generator 37. The position indicated by the arrow in FIG. 4 is the initial stop position of the rotating drum 1. Also, in this state, a synchronizing signal is obtained via the slits Pa-0 and Pb-1.
Reference numeral 38 in the figure denotes a signal generation source for setting the control element 30 to the initial state, and the control element 30 is set to the initial state when the copying machine is powered on.

Reference numeral 39 denotes a WTL level control circuit which controls the temperature in the fixing section 16 and keeps the temperature constant by controlling two heater lamps HL ₂ and HL ₃ . The output from this circuit is input to the control element 30. If the output from the circuit 39 is a logical value "1", the temperature of the fixing unit 16 has reached the specified value, and if the output is a logical value "0" It is configured to be inputted to the control element 30 as being below a specified value.

Furthermore, 40 is a circuit for detecting the slippage roller jam. That is, if an abnormality occurs in the operation of the roller 23 explained in FIG. 1, it is detected and the control element 3
The signal of that state is input to 0. In short, if the logic value is "1", it is a signal indicating that a jam condition has been detected, and if the logic value is "0", it is a signal indicating normal operation.

The control element 30 includes a ROM that stores various instructions for controlling the copying operation described in FIG. 1, a means for reading instructions from the ROM, and processes and executes the read instructions. A processing circuit that creates and outputs a control signal 33 to the driver circuit 32, and a RAM that can store and input information required by the processing circuit.
are processed by their interaction, and a control signal 33 is output to the driver circuit 32.

That is, the processing circuit receives a signal from a detection means 34 for detecting a copying operation such as an original platen, a transfer sheet, etc., corresponding to a synchronization signal 33 that is sequentially input in accordance with a copying operation, and determines the control state of the controlled section. Create control signals to drive each solenoid, relay, etc. The processing circuit executes confirmation of the input of the synchronization signal and confirmation of the detection state of the detection means 34 according to the read instructions, and generates a control signal based on these confirmations. In addition, the processing circuit also has address registers and the like for reading instructions stored in the ROM.
It is controlled by instructions read out. In order to drive controlled parts such as the drum feed clutch DFC, control signals generated by the processing circuit described above are temporarily stored in the RAM. Also, RAM
The control signals stored in are transferred to output means for output to the outside, and sent in parallel to the driver circuit 32 via this output means. That is, according to the present invention, the detection means is sequentially checked in accordance with the input synchronization signal, and the control signal is output in parallel to control the controlled section.

To briefly explain the operation of the block diagram shown in FIG. 3, the main motor MM rotates by closing the main power switch MSW shown in FIG. Control element 30 is set to an initial state. After that,
The copying machine is set to a usable state by confirming the absence of the transfer paper 13 using micro switches MS ₁ , MS ₂ and the like provided in the transfer path. In particular, if the signal from the WTL circuit 39 is "1", when the print switch PSW is pressed, the control signal 31 is output from the control element 30, the drum feed clutch DFC is turned on via the driver circuit 32, and the rotating drum 1 is turned on. Rotate. This rotation of the drum 1 causes a synchronization signal 33 to be input to the control element 30. Therefore, the control element 30 derives a strobe signal 35, checks the operating state of each microswitch, etc., and outputs the control signal 31 at that time to the driver circuit 32. In this case, the control signal is stored in the RAM, and the copying state up to that point is stored. In response to the control signal 31, a solenoid or relay is turned on via the driver circuit 32 to control charging or movement of the document table, and copying operations are sequentially performed.

Next, regarding the control operation of the copying machine according to the present invention,
This will be explained according to the flowcharts of FIGS. 5 and 6.

When the power is turned on, the main motor MM rotates as shown in the circuit diagram in Figure 2, and the control element 3
A signal for setting 0 to the initial state is input to the input section, and the control element 30 is initialized by this signal. In this case, when the O→RAM setting is completed, a test change is performed. This test image is
This is to check whether each operation is executed reliably after manufacturing the copying machine according to the present invention, and in the present invention, all of them are determined to be ON.

When the test adjustment is completed as explained above, the contact JR-a of the jam relay IR is then adjusted. If a jam occurs in the transfer paper, etc., please contact the above contact point.
JR-a closes and notifies the user that there is a jam. For convenience of explanation, we will use Jam Relay JR here.
It is assumed that JR-a is not operating and its contact JR-a is open.

In this case, the above judgment is determined to be NO, and then the jam determination means judges the microswitch group. First, turn on the micro switch MS ₁ . This micro switch MS ₁ detects the state of paper input.
At present, when the power is turned on, the insertion of the transfer paper 13 is not detected. Therefore, if the micro switch MS ₁ does not detect the transfer paper 13, the MS ₁ switch determines "NO",
Next, the detection state of the transfer paper 13 of the micro switch MS ₂ is checked. This micro switch MS ₂
is a means for detecting the separation of the transfer paper 13, and currently the transfer paper 13 is not detected when the power is turned on, and the process moves on to the next micro switch _MS8 .

Here, if the transfer paper 13 remains stagnant in the conveyance path when the power is turned on, it is processed as "Yes" in the case of MS ₁ or MS ₂ . In other words, transfer paper 1 where micro switch MS ₁ or MS ₂ stagnates
3 is detected, and the jam processing is executed accordingly.

When the power is turned on and a jam is detected, the control means executes a process for a jam warning operation according to the flow shown in FIG.

First, all loads on the copying machine are turned off. Next, at the jam relay contact JR-a,
Confirm until this contact JR-a operates and falls to the NO side, and then turn off the jam relay JR. Then, the jam lamp timer JLT is reset to "0", and the control of the contact JR-a is executed again. In this case, it is determined as Yes and the process moves to the next operation. Therefore, the jam lamp timer JLT
is started, and the jam lamp timer JLT is executed. Therefore jam lamp timer
In the case of JLT, after a predetermined time has elapsed, it is judged as Yes, and the jam lamp JL is turned on to indicate a jam, and furthermore, the K flip-flop is set. Thereafter, the above-described operation of resetting the jam lamp timer JLT and then starting the timer is repeated. Then, if the judgment of jam and lamp timer JLT turns out to be YES, the process moves to the judgment of K flip-flop. Here, since the K flip-flop is set, the jam lamp JL is turned off and the lamp goes out.
Furthermore, the K flip-flop is reset. The subsequent operation is the same as described above, and by repeating this operation, the jam lamp JL blinks at each set time of the jam lamp timer JLT to indicate a jam. The above setting time is, for example, 500 msec.

When the jammed paper is removed and the jam is cleared in the above-mentioned jam display, the power is turned on again, and after the initial setting of the control element 30, the micro switch is turned on again.
MS ₁ and MS ₂ will be played. Here, micro switches MS ₁ , MS ₂ , etc. are connected to the transfer paper 13.
If no detection has been performed, the micro switch MS ₈ is subsequently activated. This micro switch MS ₈ detects the pedestal 17 of the fixing section 16, and as mentioned above, when the power switch is turned on, the pedestal 17 rises and detects this. Therefore, when the micro switch MS ₈ is determined to be NO, that is, it is determined that the rise of the pedestal 17 cannot be detected, the micro switch MS ₈ is switched again. Therefore, if the micro switch MS ₈ is judged as Yes, then the CSSR
is teased. This CSSR is for replacing the photoreceptor 3, and in this case it is determined as "NO". If the CSSR is "ON", then a control signal for turning on the power relay PR is output from the output section of the control element 30.

Next, a test shot is performed, and after a WTL shot, the heater lamp relay is turned on, the ready lamp is turned off, and the drum feed clutch DFC is turned on. As a result, rotation of the drum 1 is started,
Heater lamps HL ₂ , HL ₃ , and HL ₁ are also turned on as necessary, and act to increase the temperature in the fixing section.

Here, the copier is in the initial state and WTL is Yes.
If so, a ready lamp RL indicating a print ready state is displayed, and by pressing the print switch PSW, the copy cycle starts. However, for convenience of explanation, the explanation will be based on the flowchart of FIG. 5.
In the flowchart of FIG. 5, the D flip-flop is reset. This D flip-flop
A flip-flop in RAM.
Specifies a flip-flop in a specific area within the file. These flip-flops provide information required by the processing circuit at the stage of processing, and are used for setting a timer circuit, changing the photoreceptor, etc., which will be described later. In the current state, each flip-flop is
It is in a reset state. After resetting the D flip-flop, the wait time level WTL is adjusted. As mentioned above, if the temperature is above a certain temperature, it is determined as Yes, and the heater lamp relay HLR is turned off and the micro switch _MS4 is turned on. That is, if the temperature is not higher than the temperature specified by WTL, the temperature is further increased using the three heater lamps HL ₁ to _{HL 3} while keeping the heater lamp relay HLR ON.

On the other hand, the micro switch MS ₄ detects the initial stop position of the document table 8 as described in FIG. 1, and if the document table 8 is in the initial state, it is determined as Yes. Therefore, turn off the document table return solenoid TRS and turn micro switch MS ₇ . Further, the document table return solenoid TRS is for returning the document table 8 to its original position, and conversely, the TFC is for moving the document table 8.

In addition, the micro switch MS ₇ detects the paper loading of the photoconductor 3 when replacing the photoconductor 3. Normally, it is tilted toward the NC side, and if the photoconductor 3 is replaced,
Photoreceptor stopper solenoid judged as NO
Turn off MSS. After that, Slipprowler Gyam SRJ is shot. This SRJ is detected by the roller 23 explained in FIG.
Input to KF. Therefore, in this case, the determination is NO and the synchronization signal PB is adjusted.

Next, in the flowchart of FIG. 5, if the PB judge is determined to be Yes, then the PA judge is performed. Here, when PB is Yes, that is, when the synchronization signal PB-1 is input to the control element 30, PA is turned on twice (Pa-1 shown in FIG. 4).
1 and Pa-0), it is determined that the drum 1 is in the initial state, and an operation to stop the rotation of the drum is executed. In other words, when PB is Yes, the synchronization signal PA
If -11 is input to the control element, the signal on PA is Yes and the signal on flip-flop D is shifted. However, if PA is determined as NO, the wait time level WTL is again determined. Therefore, if PA is judged as Yes,
Moving on to the D flip-flop jersey, this D
Flip-flop is not set (“1”)
It is judged as NO. Next, the D flip-flop is set (to "1"). After WTL confirmation is executed again, the input state of PA-0 is confirmed. Therefore, the synchronization signal PA-0 is applied to the control element 3.
If it is input to the α terminal of 0, it will be output in the PA
Determined as Yes. At this time, if the next D flip-flop is changed, it will be determined as Yes since the D flip-flop was set earlier.

After the above-mentioned operation is completed, the A flip-flop is jumped, but the A flip-flop is in the reset state and is judged as NO, and the same goes for the next B flip-flop. Furthermore, the same applies to CSSR, and it is judged as NO.

Based on the above, next is the high voltage generation relay THVR.
And the drum feed clutch DFC is turned OFF.
The above relay THVR is as explained in Figure 1,
When the relay THVR turns on, the charger 12,1
Charging is performed at step 8. Relay THVR has been in an OFF state since the power switch MSW was turned on, while feed clutch DFC is ON and rotation of the drum 1 is stopped. As will be explained later, the rotation of the drum 1 starts no matter what state the drum 1 is in when the power is turned on, and stops when the drum 1 rotates to its initial state. In other words, the drum 1
Stop.

To briefly explain what has happened so far, when the power is turned on, the inside of the control element 30 is set to the initial state, and the power relay PR is turned on to light the heater lamps HL ₂ and HL ₃ of the fixing section 16. Also, the drum 1, document table 8, etc. are set to the initial state. Incidentally, if HL ₁ is required in addition to heater lamps HL ₂ and HL ₃ of the fixing section 16, the heater lamp relay HLR is turned on to light the heater lamp HL ₁ . This state is
Stored in RAM.

Once the copier is set to its initial state as described above,
In order to perform the next operation, instructions are sequentially read from the ROM 41 and various copying controls are executed.

Once the power is turned on and the initial state is set, the sixth
In the flowchart shown in the figure, first the micro switch MS ₄ is turned on. This MS ₄ case is as explained above, and after the initial state is set, it is determined as Yes. Therefore, turn off the document table return solenoid TRS (turned off from before)
and then turn on the slide roller radium SRJ and micro switch MS ₂ . This judgment is judged as NO in both cases. On the other hand, if the microswitch MS ₂ is operating in this state, it will be treated as a jam.

Next, PB is adjusted, but since the rotary drum 1 is in its initial state, this synchronizing signal PB is naturally input to the input β of the control element 30, and is determined as Yes. In addition, if it is judged as NO in the above PB direction, the drum feed clutch DFC is turned ON to search for the initial position of the rotating drum 1 again.
and the operations described above are performed.

After the above, change WTL, but here,
If the temperature in the fixing section 16 is equal to or higher than the specified value,
WTL is determined as Yes, but if it is below the specified value, it is determined to be ON and turns on the heater lamp relay HLR and then turns off the ready lamp RL.
Then, the same operation described above is repeated. Then, when the temperature of the fixing section 16 rises and exceeds the specified value, a signal of "1" is input from the wait time bell detection circuit 39 to the input section KN ₁ .
WTL is judged as Yes, and heater lamp relay HLR is turned OFF. After that, micro switch MS ₄ is judged as Yes and TRS, CHVR,
THVR and CLR are turned off. Here, CLR is a relay for the light source lamp of the illumination device, and when the relay is turned on, the lamp CL (see FIG. 2) lights up, illuminating the document table 8.

As described above, when the power is turned on, the detection state of the transfer paper 13 by the micro switches MS ₁ , MS ₂ , etc. is confirmed, and if the micro switches MS ₁ , MS _2, etc. do not detect the transfer paper 13, the copying machine's It will be set to a state where it can be used. Therefore, the ready lamp
While RL is lit, press the print switch.
Copying starts when the PSW is operated. At this time, the transfer paper 13 is fed and conveyed along the conveyance path, but since there is no stagnant paper in this conveyance path, the transfer paper is conveyed normally without jams caused by the stagnant paper. be done.

<Effects> According to the present invention, when the power is turned on, the detection means provided on the conveyance path for conveying the transfer member,
The detection state of the transfer member is checked to determine the usable state of the copying machine, and paper transport is prevented by stagnant paper, jammed paper, etc., and normal paper transport can be performed without jamming.

Additionally, if the transfer member is present in the conveyance path,
It becomes impossible to use a copying machine, and there is no fear of smoke or fire caused by paper stuck in the fixing section.

Further, when the power is turned on, the transfer member presence/absence detection means for detecting a jam due to a conveyance failure can be used as is to detect a jam other than this jam, so a special means for this purpose is not required.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the structure of the copying machine of the present invention, FIG. 2 is a circuit diagram of the power supply section, FIG. 3 is a control block diagram of the copying machine of the present invention, and FIG. 4 is a diagram showing the operation of the recording medium. 5 and 6 are flowcharts of the control operation of the present invention, and FIG. 7 is a flowchart of jam processing based on jam detection. DESCRIPTION OF SYMBOLS 1... Drum, 3... Photoreceptor, 13... Transfer paper, 14... Paper stopper, 20... Paper feed roller, 21... Conveyance roller, 24... Synchronous disc, 3
0...Control element, 33PA, PB...Synchronization signal, 3
7...Synchronization signal generator, MS ₁ , MS ₂ , MS ₃ ...
Micro switch for paper detection.

Claims (1)

[Scope of Claims] 1. In an electrophotographic copying machine in which a toner image is formed on a recording medium and a copy image is formed by transferring the toner image to a transfer member, the toner image is disposed in the conveyance path of the transfer member. a detection means for detecting the presence or absence of a transfer member; a jam determination means for determining whether or not the transfer member is in a jam state by checking the detection state of the transfer member by the detection means when the copying machine is powered on; and the jam determination means. An electrophotographic copying machine comprising: control means for executing a jam warning operation when a jam is determined by the means.