JP2001272892A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize an operation by preventing a rush current from flowing through a transfer paper carrying unit when inserting the carrying unit into a copying machine, as for the copying machine equipped with the drawer type transfer paper carrying unit. SOLUTION: A DC power is supplied to respective carrying units 14 and 15 from the copying machine body 100 through connecters 19 and 20. Besides, the apparatus is provided with attachment/detachment detection parts 16 and 17 for detecting the loading of respective carrying units 14 and 15, and also, a front door opening/closing detection switch 18 for detecting the open/closed state of the front door for storing the carrying units 14 and 15 in the copying machine body, and the supply of the DC power is controlled by a CPU 11 in accordance with detection signals from respective detection part 16 and 17 and the detection switch 18. In supplying the power, a prescribed voltage is supplied by a power supply slow starting unit 13 for a prescribed time.

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 printer or a copying machine for forming an image on a sheet by scanning a document.

[0002]

2. Description of the Related Art As a general image forming apparatus, the configuration and operation of a copying machine and the configuration and operation of a scanning optical system thereof will be described with reference to FIG. FIG. 5 is a cross-sectional view illustrating a configuration of a copying machine that is an electrophotographic image forming apparatus.

In FIG. 5, reference numeral 100 denotes a copying machine main body;
Reference numeral 1 denotes an automatic document feeder for feeding a document to a predetermined exposure position, and reference numeral 102 denotes a document table glass as a document table.
The sheet material 103 for copying the original is a cassette 104
The sheet material 103 is sent out by the pickup roller 105.

[0004] Sheet material 103 from the cassette 104
Are separated into one sheet by separation sheet feeding rollers 106 and 107 and sent to a conveyance path 108. The sheet material is further conveyed to the resist and the roller 111 by the respective conveying rollers 109 and 110, and the resist roller 111 operates when other conditions such as an optical system are satisfied.

On the other hand, the latent image on the photosensitive drum 112 is developed by a developing unit 113 and transferred to the sheet material 103 by a transfer unit 114. The sheet material 103 is separated by the separating unit 115 so as not to be wound around the photosensitive drum 112, and is sent to the transport belt 116. Then, it is transported to the fixing roller 117 and the pressure roller 118,
After being thermally fixed here, the paper discharge rollers 119, 1
It is discharged out of the machine by 20.

When performing double-sided copying, the sheet material 103 is not discharged out of the apparatus by the flapper 121 but is once conveyed in the direction of arrow A and sent to the double-sided conveying unit 122. After that, the sheet material 103 is reversed by being fed in the direction B by switchback of the transfer roller 123, and is conveyed to the registration roller 111 via the conveyance path 124. Also, when making multiple copies on one side,
Proceeding in the direction of arrow B as it is,
Conveyed to 1.

The fixing roller 117 is for fixing the toner or the like to the sheet material 103 by heat melting.
The toner is not always fixed to the 0% sheet material 103 and may adhere to the fixing roller side depending on the density of the document.

For this reason, especially when the number of sheets passed increases, in a high-speed machine, a web (not shown) is disposed at a place other than the sheet passing portion of the fixing roller 117, and the fixing roller 117 is wound up by a predetermined amount. A mechanism for cleaning 117 is employed.

Reference numeral 125 denotes a cleaner for removing residual toner on the photosensitive drum 112, and reference numerals 126 and 127 denote sheet materials 1.
03 is a sensor that detects passage of the vehicle.

Next, an image reading operation will be described. 131 is a scanning optical system for reading an image,
An exposure lamp 132 as a document illumination lamp, a scanning mirror 133, a lens 134, and a CCD 13 as an image sensor
5. The scanning optical system 131 is driven by a motor (not shown). Then, the original is irradiated by the exposure lamp 132 while scanning by the motor, and the reflected light from the original is condensed on the CCD 135 by the scanning mirror 133 and the lens 134.

The CCD 135 sequentially converts the intensity of the reflected light into an electric signal, and sends the read image to an image processing unit (not shown). Here, the image signal is replaced with a binary value of a dark portion and a bright portion, and this signal is sent to the laser driver in the laser driver unit 136 as a laser lighting signal. The laser driver is a circuit for driving a semiconductor laser in the laser driver unit 136. A signal from the laser driver is used to form a dot, for example, in a dark portion and not in a bright portion, by a signal of the semiconductor laser. Repeat on / off. Then, the laser light emitted from the semiconductor laser is swung right and left by the rotating polygon mirror 137, and is scanned and exposed on the photosensitive drum 112 to form a large number of dots, and is read on the photosensitive drum 112. To form an electrostatic latent image of the image.

When the scanning optical system 131 performs scanning at a required speed corresponding to the magnification from left to right in FIG. 5 and at a distance required by the paper type and the magnification, the scanning optical system 131 reverses to a constant back speed. The scanning optical system 131 returns from the right to the left and stops at the home position, which is the scanning start position of the scanning optical system 131.

When a paper jam occurs during the above-described series of copying operations, the user performs a paper jam process in accordance with a display or the like designated on the operation unit by opening or closing a door that can be opened or closed according to the location where the paper jam has occurred. (This paper jam processing is called jam processing).

The occurrence of this jam is roughly divided into four places. The first is that the paper feed unit jams from the cassette 104,
The second is a vertical path conveyance section jam from the photoconductor drum 112 to the photoconductor drum 112 after feeding, the third is a horizontal conveyance section jam from the photoconductor drum 112 to the fixing section, and the fourth is a discharge jam until the sheet is discharged after fixing.

FIGS. 6 to 9 are views showing the appearance of the main body 100 at the time of jam clearance, showing a state in which a door is opened at the time of jam clearance. In the figure, 141 is a front door that can be opened and closed, 142
Is a right door that can be opened and closed, 143 is a first-stage paper cassette,
Reference numeral 144 denotes a second paper feed cassette, and the cassette 104 is a third paper feed cassette. Reference numeral 145 denotes an openable / closable fixing door. A fixing unit 146 stores the above-described fixing roller 117 and pressure roller 118 shown in FIG.

The first of the four major jams described above is a paper feed failure caused by the operation of the pickup roller 105, and as shown in FIG.
4 (Cassette 143 or cassette 144 depending on the detection location)
Is pulled out, the right door 142 of the vertical path portion is opened, and an instruction (display) is issued to perform a jam processing.

The second is when the conveying roller 109 cannot convey the sheet material 103 at a predetermined speed in the vertical path conveying section from the sheet feeding to the drum, and as shown in FIG. To open and jam
An instruction (display) is issued.

The third case is that a transfer failure occurs during transfer from the photosensitive drum 112 to the sheet material 103 or after the transfer to the fixing unit. As shown in FIG.
You will be prompted to open 1. In addition, an instruction (display) is issued to open the right door 142 of the vertical path unit according to the detected location and perform the jam processing.

The fourth is a case where the sheet is not ejected within a predetermined time after the fixing, and as shown in FIG.
A message appears asking you to open.

These operations are performed when one copying operation is set. If the copying operation is performed on a plurality of sheets, not only the jammed paper but also the sheet material 10 can be used.
Various combinations of jam processing are required so that the sheet material 103 at all the positions where 3 is detected can be processed, and a jam processing request message corresponding to the jam processing is issued.

Regarding the first, second and fourth cases, the remaining sheet material 103 can be confirmed by opening the cassette drawer or opening and closing the door, and the jam can be easily removed.

On the other hand, in the third jam processing, since it is usually the most complicated place in the main body, it is not shown, but after the front door opening / closing instruction of FIG. Several procedures such as rotation are required. In particular, when there is a sheet material 103 approaching the fixing unit, even if the processing operation is performed according to the third procedure, the processing cannot be performed, and the fourth processing procedure may be required.
The sheet material 103 is torn or requires various processing operations.

In recent copying machines, in order to improve the above-described jam clearance, a fixing device, a horizontal transport unit, or a configuration in which the two units are integrally movable and can be pulled out are mainly used.

FIG. 10 is a view showing the appearance of the main body of the movable type at the time of jam processing, and shows a state in which the fixing device and the horizontal transport section are integrated and are movable and pulled out to the front. .

In this type, for example, when a third jam occurs, conventionally, the user first opens the front door, and then places a place where a hand can be inserted by means of a lever or the like up and down so that the jam can be cleared. It can be processed if there is jam paper in the position where it can be seen, but if it reaches the fixing unit and engages with the roller of the fixing unit, it can be processed by turning the knob, pushing it downstream, and moving to the fourth processing work. Work is required.

When a plurality of copies are made, the inside of the main body is dark to protect the photosensitive drum,
Even though the sheet material is still left upstream and downstream in addition to the processed transfer material, the sheet material is overlooked, the jam processing is completed, and the processing may be required again after returning to the standby state.

As an example of the above-mentioned movable configuration in which the fixing device and the horizontal transport section are integrated, if a jam occurs, the front door is opened and the unit is pulled out to move the drum transfer section to the fixing section. Processing can be performed without overlooking the transfer material to be overlooked and removed.

Further, in the conventional machine, when the user opens the front door, the power supply unit is shut down, the power supply to the heater is stopped, the safety of the user is ensured, and the front door is opened (when the front door is opened). On the back side, there is a sticker or the like showing the details of the jam processing method, so that the user can perform the jam processing of the displayed jam location as shown in the figure.

Here, the control unit of the main body normally shifts to a stop state, all jam clearing operations are completed, and finally, the state of each detection signal is determined by closing the front door, and it is determined that there is no abnormality. If so, the operation shifts to the return operation.

On the other hand, in the case of the unit integrated type of the fixing device and the horizontal transport unit, since the jam is always pulled out of the unit, when the unit is inserted into the main body, the inside of the fixing device and the like is covered with the cover and easily. Safety can be ensured by not touching. Therefore, even if the front door is opened, it is not always necessary to shut down the power supply,
The operation unit and the like are energized as they are, and the jam clearing method and the like can be displayed.

However, since this is a movable unit and a considerable amount of current flows through the heater, if the contacts of the connector to which the heater is energized become separated while the heater is energized, a leak will occur and the life of the connector will be shortened. become. Therefore, when attaching and detaching the integral unit of the fixing device and the transport unit (when the contacts of the connector are separated), the heater must be turned off without fail. When the front door is opened, the heater is turned on in synchronization with this. The power supply is configured to be cut off without fail.

[0032]

The conventional image forming apparatus is configured as described above. For example, since the heater current of the fixing device is considerably large, the sensor and the switch are always used in a series of flows for pulling out the unit. Although the cut-off process is included so that the current is cut off, the sensor or the control board has a weak current and there is no particular leakage, so no control to cut off the current supply is performed. .

However, when a control board is provided on the unit side, a capacitive load such as a capacitor is normally connected between the power supply and GND which are supplied, and this capacitive load is slightly reduced at the moment of connection. Although it is time, a large current flows. For this reason, the power supply and the GND are affected, and for example, there is a problem that the voltage instantaneously drops or the GND potential rises.

Although there is a mechanism in which a power supply is cut off by a switch or the like merely to prevent hot insertion or removal, when a capacitive load is connected as described above, a short time may be required at the moment. Electric current flows, and as a result,
The internal circuit operation becomes unstable, and in the worst case, the voltage becomes lower than the reset voltage, which leads to a situation where a reset is applied.

The present invention has been made in view of the above problems, and an image forming apparatus capable of preventing a large current from flowing to the unit side when connected to the main body and capable of performing a stable operation. It is an object.

[0036]

An image forming apparatus according to the present invention is configured as follows.

(1) A transport unit which is provided so as to be able to be pulled out of the image forming apparatus main body and conveys the recording material, detachment detecting means for detecting that the transport unit is inserted and mounted inside the image forming apparatus main body, Connecting means for electrically connecting the transport unit to the image forming apparatus main body when the transport unit is mounted; power supply means for supplying power from the image forming apparatus main body to the transport unit; and connecting the transport unit to the image forming apparatus main body Opening / closing detection means for detecting the state of the opening / closing section to be stored in the inside, and the power supply means is controlled in accordance with each detection result of the attachment / detachment detection means and the opening / closing detection means.

(2) In the above (1), the power supply means supplies a predetermined voltage to the transport unit in a predetermined time asynchronously with the power supply to the image forming apparatus main body.

(3) In the above (1) or (2),
A control unit is provided for processing detection signals of the attachment / detachment detection unit and the open / close detection unit, and the power supply unit is controlled by the control signal of the control unit.

[0040]

Embodiments of the present invention will be described below with reference to the drawings. The configuration of the image forming apparatus according to the present embodiment is the same as that of FIG.

FIG. 1 is a block diagram showing the system configuration of this embodiment. In this figure, 100 is the same copying machine main body as in FIG. 5, 11 is a CPU that controls the entire control, and 12 is 5
A DC power supply unit (power supply means) for supplying DC power such as V, 12V, 24V, etc., 13 is a power supply slow start unit which slowly starts up the supplied 24V voltage and supplies it to the transport unit, and 14 and 15 are Each of the transport units is detachable from the copier main body 100 (can be pulled out). Reference numeral 14 denotes a fixing transport unit including a fixing unit. Reference numeral 15 denotes a transfer material (sheet material as a recording material) that has been subjected to single-sided copying during duplex copying. Is a double-sided conveyance unit having a path for reversing the sheet without discharging the sheet and conveying the sheet again to the transfer section.

Reference numerals 16 and 17 denote the above-described transport units 14,
The attachment / detachment detection unit mounted on the unit 15 allows the CPU 11 to recognize attachment / detachment of the units 14 and 15 based on the detection signal. 18 is a front door open / close detection switch (S
W) to detect the open / closed state of the front door.

Reference numerals 19 and 20 denote a drawer connector for electrically connecting the copying machine main body 100 to the transport units 14 and 15, and are connectors (connection means) which can be easily inserted and removed. Thereby, the units 14, 15
Can be easily attached and detached by the user. FIG. 2 shows the appearance of a general drawer connector.

Here, the attachment / detachment detecting sections 16 and 17 are provided as attachment / detachment detecting means for detecting that the respective transport units 14 and 15 are inserted and mounted inside the copying machine main body. The front door opening / closing detection switch 18 is provided as opening / closing detection means for detecting the open / closed state of an opening / closing section (front door) for storing the transport units 14 and 15 in the copying machine main body. The CPU 11 serving as a control unit processes each detection signal of each of the detection units 16 and 17 and the detection switch 18 and controls the DC power supply unit 12.
In this embodiment, a control signal is output to the power supply slow start unit 13 to control the power supply from the DC power supply unit 12 to each unit. At this time, the slow start unit 13 supplies a predetermined voltage to the transport units 14 and 15 in a predetermined period of time asynchronously with the power supply to the copier body 100.

In the configuration shown in FIG.
When it is detected that the front doors 4 and 15 are mounted and the front door is closed, an ON signal is sent from the CPU 11 to the power supply slow start unit 13 as a control signal. This allows
When the output of the slow start unit 13 is turned on, the voltage of 24V slowly rises, and each transport unit 14, 1
5 is supplied.

FIG. 3 shows the voltage / current waveforms of the present embodiment in which the above-mentioned 24 V was slowly started. FIG. 4 shows a conventional voltage / current waveform.

In this embodiment, the power supply is controlled via the CPU 11. The ON / OFF signal sent to the power supply slow start unit 13 is transmitted to each of the transport units 14 and 15 and the front door open / close detection switch 18. It is needless to say that it may be directly generated and input from the open / close detection signal.

As described above, after the transport units 14 and 15 are securely connected to the copying machine main body 100, a predetermined time is further required to output a predetermined voltage. It is possible to supply current without causing any problem, and it is possible to reliably avoid the above-mentioned instability of circuit operation and resetting, thereby stabilizing the operation of the main body.

[0049]

As described above, according to the present invention,
The predetermined voltage can be supplied after the transport unit is securely connected to the image forming apparatus main body.Especially, even when the capacitive load is connected, the current is supplied without causing a large current due to the rush current of the capacitive load. This can reliably prevent the circuit operation from being unstable due to an instantaneous large current and from being reset, and can stabilize the operation of the main body.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of a general drawer connector.

FIG. 3 shows the voltage /
Diagram showing current waveform

FIG. 4 shows a conventional voltage / current waveform.

FIG. 5 is a sectional view showing a configuration of a copying machine.

FIG. 6 is a perspective view showing the appearance of the main body during jam processing.

FIG. 7 is a perspective view showing the appearance of the main body during jam processing.

FIG. 8 is a perspective view showing the appearance of the main body during jam processing.

FIG. 9 is a perspective view showing the appearance of the main body during jam processing.

FIG. 10 is a perspective view showing the appearance of the main body during jam processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 CPU (control part) 12 DC power supply unit (power supply means) 13 Power supply slow start unit 14 Fixing conveyance unit 15 Double-sided conveyance unit 16 Detachment detection part (means) 17 Detachment detection part (means) 18 Front door open / close detection switch ( Means) 19 Connector (Connecting Means) 20 Connector (Connecting Means) 100 Copier Main Body (Image Forming Apparatus Main Body) 101 Automatic Document Conveyor 103 Sheet Material (Recording Material) 112 Photosensitive Drum 117 Fixing Roller 118 Pressure Roller 131 Scanning Optical System 132 Document illumination lamp 133 Scanning mirror 134 Lens 135 CCD 136 Laser driver unit 137 Rotating polygon mirror

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C061 AP04 AQ06 HJ02 HJ10 HK08 HK11 2H027 DA26 DA27 ED30 EE06 EJ17 ZA01 ZA04 ZA09 5C062 AA05 AB29 AB41 AB49 AC58 AD02 AD05 BA00 9A001 BB06 HH34 JJ35 KK42 LL

Claims (3)

[Claims] A transport unit that is provided so as to be able to be pulled out of the image forming apparatus main body and transports a recording material; a detachment detecting unit that detects that the transport unit is inserted and mounted inside the image forming apparatus main body; Connecting means for electrically connecting the transport unit and the image forming apparatus main body when the unit is mounted; power supply means for supplying power to the transport unit from the image forming apparatus main body; and connecting the transport unit to the image forming apparatus main body. And an opening / closing detecting means for detecting a state of the opening / closing section for storing in the image forming apparatus, wherein the power supply means is controlled in accordance with each detection result of the attaching / detaching detecting means and the opening / closing detecting means. . 2. The image forming apparatus according to claim 1, wherein the power supply unit supplies a predetermined voltage to the transport unit in a predetermined time asynchronously with the power supply to the image forming apparatus main body. . 3. The image according to claim 1, further comprising a control unit that processes detection signals of the attachment / detachment detection unit and the opening / closing detection unit, wherein the power supply unit is controlled by the control signal of the control unit. Forming equipment.