JPH0362051A - Image forming device - Google Patents

Abstract

PURPOSE:To carry out life control for a fixing device, etc., with a simple constitution and also with accuracy by providing a first fuse for discriminating between the new and the old, and a second fuse for control of life inside the fixing device. CONSTITUTION:The first fuse 176 for discriminating between the new and the old and the second fuses 174 and 175 for control of the life are provided in the fixing device, when the power source is connected, whether the fixing device is new or old is discriminated by the state of the first fuse 176, and the life of the fixing device is discriminated by the state of the second fuses 174 and 175. Then, when the new fixing device is discriminated, the first fuse 176 inside the fixing device is cut off, after the first fuse 176 is cut off, fixed number of pieces by the fixing device is counted, and when this counted value exceeds the specified number, the second fuses 174 and 175 in the fixing device are cut off. Thus, the life control of the fixing device etc. can be carried out with a simple constitution and with accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus used in, for example, a one-note printer, a digital copying machine, a facsimile machine, and the like.

(Prior Art) Conventionally, in image forming devices, especially laser printers, the photoreceptor, developing device, fixing device, etc. have different lifespans, so they are made into separate units and inserted (installed) in a cartridge type. , or that can be taken out or removed) have been developed.

In such devices, the lifespan of the fusing device is managed by an electromagnetic counter installed in the fusing device, a recognition code is given to the fusing device and managed by a counter on the main body, or a fuse is installed to distinguish between the new and the old. The determination is made based on whether or not it is fused.

When the fixing device is managed using an electromagnetic counter, there is a problem that the main body cannot know the count value and the user cannot check the lifespan of the fixing device without looking at it one by one.

In the case of management using a recognition code, a circuit must be provided to output the recognition code to the fixing device, and in order to distinguish using the recognition code, it must be stored in the memory of the main unit, which requires a large memory capacity. The problem is that it requires If the lifespan is managed using fuses for distinguishing old and new fuses, there is a problem in that when another fixing device is inserted, it cannot be determined whether the fuser's life has passed or not.

Therefore, there is a drawback that lifespan management of the fixing device and the like cannot be performed accurately with a simple configuration.

(Problem to be Solved by the Invention) The present invention eliminates the drawback that lifespan management of a fixing device, etc. cannot be performed accurately with a simple configuration. An object of the present invention is to provide an image forming apparatus that can perform image forming operations accurately.

[Structure of the Invention] (Means for Solving the Problems) An image forming apparatus of the present invention has a fixing device that is detachable and forms an image, and a first one for distinguishing old from new in the fixing device. A fuse and a second fuse for life management are provided, and when the power is turned on, it is determined whether the fixing device is old or new based on the state of the first fuse, and the life of the fixing device is determined based on the state of the second fuse. a first determining means for cutting a first fuse in the fixing device when the determining means determines that a new fixing device is provided;
a cutting means, a counting means for counting the number of sheets fixed by the fixing device after the first fuse is cut by the first cutting means, and a counting means for counting the number of sheets fixed by the fixing device; In this case, the fixing device includes a second cutting means for cutting the second fuse in the fixing device.

In the image forming apparatus of the present invention, the fixing device is configured to be detachable and performs image formation, and the fuser in the fixing device is provided with a plurality of fuses for life management indicating an operating voltage range. a determining means for determining the operating voltage range of the fixing device, an indicating means for indicating the operating voltage range of the fixing device, and whether or not the operating voltage range according to the indicating means matches the operating voltage range according to the determining means. It consists of a determining means for determining whether the

The image forming apparatus of the present invention has a structure in which fixing devices with different operating voltage ranges are detachable and forms images, and a plurality of fuses for life management indicating operating voltage ranges are provided in the fixing device, an output means for outputting a power supply voltage, a determination means for determining the operating voltage range of the fixing device using a fuse in the fixing device, an indicating means for indicating the operating voltage range of the fixing device, an operating voltage range by the indicating means and the above. determining means for determining whether or not the operating voltage ranges match the determining means; and if the determining means determines that the operating voltage ranges match, supplying the output voltage from the output means to the fixing device; It consists of supply means.

(Function) The present invention has a fixing device configured to be detachable and performs image formation, in which a first fuse for distinguishing old from new and a second fuse for life management are provided in the fixing device,
When the power is turned on, it is determined whether the fixing device is new or old based on the state of the first fuse, the lifespan of the fixing device is determined based on the state of the second fuse, and if a new fixing device is determined, the fixing device is After the first fuse is cut, the number of sheets fixed by the fixing device is counted, and if this count is greater than a predetermined number, the second fuse in the fixing device is cut. It is designed to cut the fuse of the

The present invention has a fixing device that is detachable and forms an image, in which a plurality of fuses for life management indicating an operating voltage range are provided in the fixing device, and the fuses in the fixing device cause the fixing device to The operating voltage range of the fixing device is determined, the operating voltage range of the fixing device is specified, and it is determined whether the specified operating voltage range matches the determined operating voltage range. .

The present invention has a structure in which fixing devices with different operating voltage ranges are detachable and performs image formation. determines the operating voltage range of the fixing device using the fuse, instructs the operating voltage range of the fixing device, and determines whether the operating voltage range according to the instruction matches the determined operating voltage range. According to this determination, if the operating voltage ranges match, the output voltage from the output means for outputting the power supply voltage is supplied to the fixing device.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the external appearance of an electrophotographic image forming apparatus using a semiconductor laser, and FIG. 3 shows its internal configuration. This image forming device (laser printer) is connected to a host system (external device such as a computer or word processor).
(not shown) via a transmission controller such as an interface circuit. When a print start signal is received from the host system, the image recording operation is started, and the image is recorded on paper as a transfer material and output.

This image forming apparatus has the following configuration.

That is, numeral 1 in the figure is a main body of the apparatus, and a main control board 2 is disposed in the center of the main body 1, as shown in FIG. An electrophotographic process unit 3 for forming images is arranged behind the main control board 2 (to the right in the state shown in Fig. 3), and a plurality of function-adding controls are arranged at the lower front. A control board accommodating section 5 for accommodating a plurality of boards 4 is also provided with a paper discharge section 6 formed at the upper front thereof.

Up to three function addition control boards 4 can be installed depending on the degree of function addition (for example, adding types of fonts, kanji, etc.). Further functions can be added by inserting function-adding IC cards 17 into three IC card connectors 16 arranged on the front edge of the board 4. Furthermore, two interface connectors (not shown) are arranged on the left end surface of the control board 4 for adding functions located at the bottom, and these interface connectors are installed on the left side surface of the device main body 1. It faces the formed opening 18 (see FIG. 2).

Further, a lower portion inside the apparatus main body 1 is a cassette accommodating section 8 that accommodates a paper feed cassette 7.

As shown in FIG. 2, the paper ejection section 6 is a recess formed on the front upper surface of the main body 1 of the apparatus, and the front edge of the paper ejection section 6 has a recess that can be folded into the paper ejection section 6 or unfolded as shown in the figure. A rotatable paper discharge tray 9 is provided. Further, a notch 9a is formed in the center of the front end of the paper ejection tray 9, and a rotatable U-shaped auxiliary member that can be accommodated in the notch 9a or unfolded as shown in FIG. A paper discharge tray 10 is provided. The size of the paper discharge section 6 can be adjusted according to the size of the paper P to be discharged.

Further, on the upper surface of the left frame portion 1a of the main body of the apparatus located on the left side of the paper ejecting portion 6, a control panel 14 is provided with an LED II for display, a 7-segment display 12 for displaying a two-digit status, and a switch 13. are arranged, and a manual feed tray 15 is attached to the rear side of the apparatus main body 1.

Next, the electrophotographic process unit 3 that performs electrophotographic processes such as charging, exposure, development, transfer, peeling, cleaning, and fixing will be described with reference to FIGS. 3 and 4.

A drum-shaped photoreceptor 20 serving as an image carrier is disposed approximately in the center of the unit accommodating portion, and this photoreceptor 2
0, a scorotron charger 21, an exposure section 22a1 of a laser exposure unit 22 as an electrostatic latent image forming means, and a magnetic brush type that simultaneously performs the development process and the cleaning process. a developing device 23 and a transfer charger 24 consisting of a scorotron.
, a memory removal brush 25, and a pre-exposure lamp 26 are arranged in this order.

Further, inside the apparatus main body 1, paper P fed from the paper cassette 7 via the paper feeding means 27 and paper P manually fed from the manual feed tray 15 are transferred between the photoreceptor 20 and the transfer charger 24. A paper conveyance path 29 is formed which leads to a paper discharge section 6 provided on the upper surface side of the apparatus main body 1 via an image transfer section 28 between the two.

A pair of transport rollers 30. Aligning roller pair 31. and a conveying roller pair 32 are arranged, and a fixing device 33 as a fixing unit and a paper ejection roller unit 34 are arranged on the downstream side. Further, a cooling fan unit 35 is disposed above the location where the pair of conveyance rollers 32 are disposed.

Note that an aligning switch 36 is provided near the aligning roller pair 31, and an aligning switch 36 is provided near the aligning roller pair 31.
A conveyance guide 37 is provided near 8.

When a print start signal is received from the host system, the drum-shaped photoreceptor 20 rotates and the photoreceptor 20 rotates.
is charged by the charger 21. Next, the laser beam a modulated in response to the dot image data from the host system is scanned and exposed onto the photoconductor 20 using the laser exposure unit 22, and an electrostatic latent image corresponding to the image signal is formed on the photoconductor 20. form. This electrostatic latent image on the photoreceptor 20 is formed by toner t in the developer magnetic brush D' of the developing device 23.
The image is developed and visualized.

On the other hand, in synchronization with this toner image forming operation, the paper P taken out from the paper feed cassette 7 or manually fed from the manual feed tray 15 is fed through a pair of aligning rollers 31, and is formed on the photoreceptor 2o in advance. The toner image thus obtained is transferred onto the paper P by the action of the transfer charger 24.

Next, the paper P passes through two paper conveyance paths and reaches the fixed M device 3.
3, and the toner image is fused and fixed onto the paper P.

Thereafter, the paper is discharged to the paper discharge section 6 via the paper discharge roller unit 34.

Note that after the toner image is transferred onto the paper P, residual toner remaining on the photoreceptor 20 is removed by a memory removal brush 25 made of a conductive brush.

Mori removal is done.

Further, as shown in FIG. 4, the fixing device 33 includes a heat roller 41 having a built-in heater lamp 4o, and a pressure roller 42 that is in pressure contact with the heat roller 41. The toner image is fused and fixed on the paper P as the paper P passes between them.

Further, the heat roller 41 and the pressure roller 42 are surrounded by a lower casing 43 and an upper casing 44, and are structured to prevent heat from escaping to the outside as much as possible to ensure a favorable temperature atmosphere necessary for fixing. ing.

A cleaner 45 is in contact with the heat roller 41, and the temperature is controlled by a thermistor 46 to maintain the temperature necessary for fixing. It is configured to be done.

Further, a paper guide 48 is disposed within the upper casing 44 and near the upstream side of the contact portion 47 between the heat roller 41 and the pressure roller 42, and the paper guide 48 is arranged to ensure that the leading edge of the paper P guided to the fixing device 33 is guided to the heat roller. 41 and the pressure roller 42. Note that on the paper exit side of the fixing device 33, a paper guide 49 is provided integrally with the lower casing 43 to guide the fixed paper P to the paper discharge roller unit 34.

Further, the transport guide 3 is located on the transport direction side of the transfer charger 24 and guides the non-image side of the paper P.
7 is in a grounded state and functions to electrostatically attract and float the paper P.

Further, the paper ejection roller unit 34 includes a lower roller 50
and an upper roller 51, and the paper P is
A static eliminating brush 52 is provided in contact with the non-image forming surface of the image forming apparatus. Upper roller 51 and static elimination brush 5
The upper half including the transport guide 37. The transfer charger 24 and the like are attached to the lower surface side of the top cover 60 of the main body 1 of the apparatus.

The top cover 60 can be rotated up to a maximum of about 120 degrees, as shown in FIG. This allows most of the two paper transport paths to be exposed, and also allows the equipment facing the paper transport path 29 to be exposed.

This makes it easy to remove paper jams and perform maintenance, inspection, and replacement of equipment. Note that 62 shown in FIG. 5 is an ozone filter, and 63 is a toner cartridge.

Further, the rear cover 64 of the apparatus main body 1 shown in FIG. The curved conveying section can be opened, and the paper P stuck in this section can be easily removed.

Furthermore, as shown in FIG. 5, the fixing device 33 can be attached and detached with the top cover 60 open. As shown in FIGS. 13 and 14, a connecting section 172 is provided at the bottom of the fixing device 33, and this connecting section 172 connects to a control circuit 133, which will be described later.
It is designed to be electrically connected to. The connecting part 1'72 has a guide pin 1701170 for insertion.
1 and the protective sheet metal 1 which is longer in width and higher in height than the connecting part 172 and prevents the connecting part 172 from being damaged.
71 is provided. The connecting portion 172 includes a connector terminal 172a.

172b. The connector terminal 172a is a terminal to which a heater lamp 40 inside the fixing device 33 and a thermo fuse (not shown) are connected, and since a current of 10 A flows when the AC input voltage is 100 V, the connector terminal 172a has a large area. . The connector terminal 172b is connected to a thermistor 46 inside the fixing device 33 and a fuse 1 to be described later.
74, 175, and 176 are connected terminals, and since the flowing current value is about 1 to 300 mA, the area of the terminals is smaller than that of the connector terminal 172a.

Further, as shown in FIG. 4, the laser exposure unit 2
2 is a semiconductor laser oscillator 90 (not shown in detail), a polygon scanner 93 consisting of a polygon mirror 91 and a mirror motor 92, and a second lens 941.2 for FE. The device is composed of a second lens 95 for FE, reflective mirrors 96 and 97 for scanning the scanned laser beam a to a predetermined position, and the control board 101 of this laser exposure unit 22 has a connector 102. It is connected to the main control board 2 via the main control board 2.

Furthermore, the laser exposure unit 22 is housed in a synthetic resin casing 103 that is open at the bottom, and the bottom opening of the casing 103 is connected to a metal shield plate 104.
At the same time, the casing 1
A shield cover 105 made of metal and also serving as a reinforcing plate is superimposed on the upper surface side of 03. A conductive contact piece 106 is connected to the shield cover 105.
When the laser exposure unit 22 is attached to a predetermined position via an attachment means (not shown), this contact piece 106 comes into contact with a metal guide rail that slidably guides the developing device 23, and the contact piece 106 comes into contact with a metal guide rail that slidably guides the developing device 23. This prevents malfunctions caused by the negative effects of static electricity on the inside.

Note that the photoreceptor 20 uses an organic photoconductor,
It has a structure in which a charge generation layer and a charge transport layer covering this charge generation layer are formed on the surface of an aluminum cylinder.

Further, the developing device 23 employs a reversal developing method in order to simplify the electrophotographic process, and also employs a method in which the removal of the transfer residual toner t is performed simultaneously with the development. As shown in FIG. 4, this developing device 23 includes a photoreceptor 20 and a developing roller 122 provided in a casing 121 having a developer accommodating portion 120. contains a two-component developer consisting of toner (colored powder) T and carrier (magnetic powder) C. Further, a sliding contact portion with the photoreceptor 20 of the developer magnetic brush D′ formed on the surface of the developing roller 122;
That is, a doctor 124 for regulating the thickness of the developer magnetic brush D' is installed upstream of the development position 123 in the rotational direction of the photoreceptor 20. Further, the developer storage section 120 includes a first. Second developer stirring body 12
5126 is accommodated. Note that the developing device 23 includes:
Toner cartridge 63 (fifth) as a toner supply device
(see figure) is installed to replenish the developer storage section 120 with toner t as appropriate.

Further, the developing roller 122 has three magnetic pole parts 127.12.
It is composed of a magnetic roll 130 having numbers 8, 129 and 7, and a non-magnetic sleeve 131 that is fitted onto the magnetic roll 130 and rotates clockwise in the figure. magnetic roll 13
Of the three magnetic pole parts 127, 128, 129 of 0, the magnetic pole part 128 facing the development position 123 is the N pole, and the other magnetic pole parts 127, 128 are the S poles. Also, the angle e between the magnetic pole part 127 and the magnetic pole part 128 (see Fig. 4 @) is 1.50', and the angle O between the magnetic pole part 128 and the magnetic pole part 129 (see Fig. 4) is 120''. The photoreceptor is then At the same time as the development of the electrostatic latent image on 20,
The remaining toner is collected electrically.

Furthermore, as shown in FIG. 5, this developing device 23 includes:
Photoreceptor 20. Electrostatic charger 21. Memory removal brush 2
5 and the like are integrated into a process cartridge 85, and this process cartridge 85 can be taken in and out of the apparatus main body 1. Further, a cleaning brush 144 for cleaning the lower roller 31a of the aligning roller pair 31 is attached to the upper surface of the process cartridge 85.

Further, on the back side 1a of the main body 1, as shown in FIGS. 6 and 8, there is a power switch 68 for opening and closing the AC power supply.
ACI shown in Figure 7! 6 connectors (female bottles) to which the connectors (male pins) 57 of the source cord 66 can be attached and detached;
An input voltage selector switch 70, a green indicator 71, and a red indicator 72 are provided. The lighting of the green display 71 and the red display 72 is controlled by an overvoltage protection device 161, which will be described later. The connector part 69 has a female pin configuration that prevents the active part from being exposed even if the connection with the connector part 57 is disconnected while the plug of the AC power cord 66 is inserted into the power outlet. Green indicator 7
1 lights up when the AC input terminal reaches the operating voltage range of the device, and the red indicator 72 lights up when an overvoltage AC input voltage that exceeds the device's operating voltage range is applied. Each display 71. indicates whether the input voltage is appropriate.
This can be notified by whether or not 72 is lit.

The input voltage changeover switch 70 is a switch for indicating the operating voltage range for the input voltage by switching in accordance with the operating voltage of the image forming apparatus, and is 100V in Japan and 115V in North America.

It can be switched to the European 220V operating voltage.

The operating voltage range for each input voltage is set in the range of 80% to 120% of the input terminal, and before and after that, the indicator lights up, or the bidirectional thyristor 182 for overvoltage protection, which will be described later, turns on. It will be turned off. However, in the case of 220V in Europe, considering the common specifications between the UK and the continent, 80% of 220V, 240V No. 1
20% is set as the operating voltage range.

For example, as shown in FIG. 11, when the input voltage selector switch 70 is set to the 100V position, if the AC input voltage becomes lower than 80V, the green indicator 7
1. Turn off the red indicator 72 and turn off the bidirectional thyristor 182.
is turned off, and when the AC input terminal is between 80V and 120V, the green indicator 71 lights up and the bidirectional thyristor 182
is turned on, and when the AC input terminal becomes higher than 120V, the green display 71 and the red display 72 are turned on, and the bidirectional thyristor 182 is turned off.

Furthermore, when the input terminal selector switch 70 is set to the 120V position, if the AC input terminal becomes lower than 96V, the green indicator 71 and red indicator 72 are turned off, and the bidirectional thyristor 182 is turned off. , AC input voltage is 9
When the voltage is between 6V and 144V, the green indicator 71 is lit, the bidirectional thyristor 182 is turned on, and the AC input voltage is 1
When the voltage exceeds 44V, the green indicator 71 and red indicator 72 are turned on, and the bidirectional thyristor 182 is turned off.

In addition, when the input voltage selector switch 70 is set to the 220V position, if the AC input voltage becomes smaller than 176V, the green indicator 71 and the red indicator 72 are turned off, and the bidirectional thyristor 182 is turned off. However, if the AC input voltage is between 176V and 288V, the green indicator 71
lights up, turns on the bidirectional thyristor 182, and when the AC input voltage becomes greater than 288V, the green indicator 7
1. Turn on the red indicator 72 and turn on the bidirectional thyristor 182.
Turn off.

Next, the control system of the present image forming apparatus will be explained with reference to the block diagram shown in FIG. In the figure, 131 is an external device that is connected via the aforementioned interface connector.

As this external device 131, a host system such as an electronic computer, a word processor, an image processing device, etc. is connected. This external device 131 is an interface circuit 132
It is electrically connected to this device via.

The following interface signals for this interface circuit 132 are prepared.

In other words, the IVCLKO signal is transmitted from this device to the external device 132.
The external device 131 outputs 8-bit image data IVD in synchronization with this clock signal.
Output AT70-00.

The IH5YNO signal is a horizontal synchronization signal that is output from the present device to the external device 131 prior to the transfer of image data for one scan. IDAT71-0] signals are bidirectional 8
A bit data bus signal is used to receive commands from an external device 131 via this bus, and to output a status indicating the state of the device to the external device 131.

The ID5TAO signal is a signal that determines the direction of data transfer on the 8-bit data bus, and the 15TBO signal is a strobe signal for this device to receive commands, both of which are output from the external device 131.

The IBSYO signal is a busy signal indicating that the device is processing a command from the external device 131. IAT
The NI signal is an attention signal output by the device when a situation that the external device 131 should immediately know about occurs in the device. The IPRDYO signal is a signal indicating that the device is in a ready state. IPRIMEO signal is external device 1
31 is a reset signal output to this device. l5CL
The RI signal is a clear signal that the device outputs to the external device 131 when the device is powered on and off.

Signals taken into the device from this interface circuit 132 are supplied to a control circuit 133 and an image signal processing circuit 137.

The control circuit 133 is composed of a microcomputer and its peripheral circuits, and processes various data and performs various controls.

The main functions of this control circuit 133 are listed as follows:
It is as follows. (1) Interface circuit 13
2, that is, commands from the external device 131, and controls each part of the device according to the instructions. Also,
The status corresponding to the command is output to the external device 131 through the interface circuit 132. Also I
Controls the output of the ATN1 signal, IPRDYO signal, and l5CLRI signal. (2) Control panel 14
The display contents are output to a display circuit 134 that drives the LED II and 7-segment display 12.

(3) Controlling on/off of various solenoids 135. (4) Information from various switches 136 is taken in and processed. (5) Image signal processing circuit 137
For this purpose, various parameters are set and internally generated pattern data is sent.

(6> For the mirror-motor/laser drive circuit 138,
It controls on/off of the mirror motor 92, sets the power of laser emission, and monitors the power.

(a) Controls on/off of the light emitting diodes of toner concentration sensors 143 and 144, and processes toner concentration information from both sensors 143 and 144. (8) High voltage power supply 14
5 is controlled. That is, output on/off control and output power setting for the charging charger 21, output on/off control and output power setting for the charging grid 140, and output on/off control for the transfer charger 24.
Off control and output power setting, output on/off control and output power setting for the transfer grid 139, output on/off control and output power setting for the developing bias, output on/off control and output power for the memory removal brush 25 Make settings.

It also monitors whether each output is operating normally. (9) On/off control of the main motor 150 and monitoring of steady rotation are performed. (
10) On/off control of the fan motor 151 is performed. (11) On/off control of the pre-exposure lamp 26 is performed. (12> Heat roller 41 of fixing device 33
solid state relay (SSR) 165 by monitoring the temperature of
The on/off control of the heater lamp 40 is performed by switching. (13) Depending on the state of the two fuses in the fixing device 33 and the count contents of the memory 153, old and new discrimination, life management, life discrimination, voltage specification of 100V series and 200V series, etc. are performed. (14) The switching signal from the input voltage selection switch 70 causes the device to switch between 100V, 120V,
It is determined whether the setting of 220V or less voltage specification matches the voltage specification determined by the fuse in the fixing device 33.

As briefly explained above, the control circuit 133 corresponds to the command section of this device.

As shown in FIG. 9, the heater lamp 40 of the fixing device 33 includes the AC power cord 66 and the connecting portion 5'7.
．． 59, breaker 160, power switch 68, overvoltage protection device 161, changeover switch 164, solid state relay (SSR) 165, and thermofuse 16
An AC input terminal from an AC power source (not shown) is supplied via 6. In addition, the high voltage power supply 145 connected to the subsequent stage of the overvoltage protection circuit 161 also has an AC power supply.
AC input voltage from the power supply is supplied, and the selector switch 16
The fan motor 151 connected to the rear stage of 4 is also connected to AC.
AC input voltage is supplied from the power supply.

The overvoltage protection device 161 is provided after the power switch 68, and the overvoltage protection device 161 is provided when the supplied AC input terminal is at a voltage lower than the operating voltage range (low voltage) or when the supplied AC input voltage is higher than the operating voltage range. (overvoltage), the application of the AC input voltage to the subsequent stage is stopped, and the above-mentioned blue display 71 and red display 72 are controlled to light up. It is constituted by an internal circuit 163 of a bidirectional thyristor 182. The overvoltage protection circuit 162
As shown in the figure, a diode stack 18 for full wave rectification
0, a protective resistor R1 for voltage drop, a changeover switch 181 that switches in conjunction with the input voltage changeover switch 70, and a Zener diode D for voltage drop to the changeover switch 181.
1, D2, D3, a smoothing circuit 183 composed of a Zener diode D4 for Zener clamping, a capacitor ClSC2, a resistor R2, a resistor R3, R4, R for voltage division.
5. Consists of an npn transistor T1, resistors R7 and R8, a green indicator 71, a red indicator 72, and a light emitting diode D5. As shown in FIG. 10, the internal circuit 163 includes a photothyristor D6, which forms a photocoupler with the light emitting diode D5, a resistor R10, a Snpn type transistor T2, voltage dividing resistors R.11, R12, R13,
R14, protective resistor R15, diodes D7, D8, D9
, DIO, capacitors C3, C4, C5, resistor R15,
It is composed of R16 and R17.

When the power switch 68 is turned on and an AC input terminal within the operating voltage range corresponding to the switching position of the input voltage selector switch 70 is input, the AC input voltage is full-wave rectified by the diode stack 180 and then rectified by the protective resistor R1. After the voltage drops, it reaches the Zener diodes D1-D3. At this time,
The selector switch 181 is switched according to the switching position of the input voltage selector switch 70. After the AC input voltage also drops in Zener diodes D1 to D4, it is smoothed by capacitor C1, resistor R2, and capacitor C2, and is applied to resistors R3, R4, and R5. During this period, each waveform is the 12th waveform.
As shown in the figure, (a) shows the AC input terminal waveform from the AC power cord 66, and (b) shows the AC input terminal waveform from the AC power cord 66.
shows the waveform after full-wave rectification output from the diode stack 180, (C) shows the waveform after Zener clamping from the cathode of Zener diode D4, and (d) shows the waveform from capacitor C2 to resistor R3, red The display 72 shows the waveform after capacitor smoothing applied to the resistor R8.

The voltage divided by resistors R3 and R4 is applied to resistor R5 and transistor T1, but since it is lower than the threshold level of transistor T1, transistor T1 is off and red indicator 72 does not light up. The voltage applied to the light emitting diode D5 through the resistor R8 causes the light emitting diode D5 to
lights up, and the light is transmitted to Photothyrisk D6. Further, voltage is applied to the green display 71 via the resistor R7, causing the green display 71 to light up. The lighting of the green indicator 71 notifies the user that the AC input terminal is appropriate. The above light emitting diode D5 and photothyristor D6
A photocoupler is formed.

Furthermore, in the internal circuit 163, a resistor R17 and a capacitor C5 are connected in parallel to a bidirectional thyristor 182, and a bidirectional thyristor 18 is connected in series to a human-powered AC line.
2. It performs noise absorption. Also, capacitor C
3, C4, and resistor R16 absorb noise from the gate G of the bidirectional thyristor 182. When an AC input voltage is supplied where the voltage on the ahood A side of the bidirectional thyristor 182 is larger than the voltage on the cathode side, voltage is applied to the diode D7 via the protection resistor R15, the diode D7 is turned on, and the diode D8 is turned on. is off, voltage dividing resistors R12, R
11, joins R13. Since the AC input voltage is a sine wave, the initial divided voltage is below the threshold level of transistor T2, and transistor T2 is off. At this time, when the light emitting diode D5 is lit and its light is transmitted to the photothyristor D6, the photothyristor D6 is turned on and the AC input voltage is changed to the diode D1.
0 and is applied to the gate G of the bidirectional thyristor 182, turning on the bidirectional thyristor 182. When the AC input voltage increases according to the sine curve, the transistor T
The divided voltage applied to T2 becomes above the threshold level, turning on transistor T2. Transistor T2
The on and off cycles are repeated according to the sine curve of the AC input terminal, and even if light is applied to the photothyristor D6, the photothyristor D6 will not turn on unless the transistor T2 is off, that is, when the AC input voltage is at zero cross. does not turn on, and as a result, bidirectional thyristor 1
82 will turn on at the zero cross timing.

In addition, when an AC input voltage is supplied where the voltage on the anode A side of the bidirectional thyristor 182 is smaller than the voltage on the cathode side, the cathode of the bidirectional thyristor 182
A voltage is applied to gate G1 diode D9, and as in the case described above, bidirectional thyristor 182 is turned on only when the AC input terminal is at zero cross and light is being transmitted to photothyristor D6.

As described above, when the AC input voltage is within the operating voltage range, the bidirectional thyristor 182 is turned on at the zero cross timing, and the heater lamp 40, high voltage power supply 145, and fan motor 1
Supply voltage to 51 etc.

In this manner, by turning on the bidirectional thyristor 182 at the timing of zero cross, it is possible to prevent surge current from flowing due to the capacitor load in the high voltage power supply 145 and the lamp load of the heater lamp 40.

In addition, when the AC input terminal is at a low voltage lower than the operating voltage range, the Zener diodes D1, D2, and D3 do not turn on, the light emitting diode D5 does not light up, and the photothyristor D6
is off, so the bidirectional thyristor 182 is off. Therefore, when the AC input terminal is at a low voltage, no voltage is applied to the heater lamp 40, high voltage power supply 145, fan motor 151, etc., so it is possible to prevent failure of the switching power supply due to low voltage operation.

In addition, when the AC input terminal has an overvoltage higher than the operating voltage range, the light emitting diode D5
or lights up, and the blue display 7] lights up. However, resistance R3
, R4 becomes above the threshold level of transistor T1,
is turned on and the red indicator 72 is lit, but the light emitting diode D5 is turned off and the bidirectional thyristor 182 is turned off. Therefore, when the AC input voltage is an overvoltage, no voltage is applied to the heater lamp 40, high-voltage power supply 145, fan motor 151, etc., so thermal destruction of the heater lamp 40 due to overvoltage can be prevented. At this time, both the green indicator 71 and the red indicator 72 light up,
It is possible to display and notify the user that overvoltage is being applied manually.

In addition, since the light emitting diode D5 and the photothyristor D6 are optically coupled, if an optical fiber is used to connect them, the overvoltage protection circuit 62 and the internal circuit 16 can be connected.
It can be placed separately from 3. Furthermore, since the internal circuit 163 switches a large current, it is necessary to lower the impedance of the wiring, but by electrically separating it by optical coupling, the overvoltage protection circuit 162 side does not have to be subject to such restrictions. .

Furthermore, as shown in FIG.
Fuse 174 for life management of 00 series, Fuse 175 for life management of 200 series, Fuse 176 for distinguishing old from new.
are connected at the time of manufacture. In other words, the new 100V specification and 120V specification fixing device 33 has
Fuses 174 and 176 are connected and new (7) 220
Fuses 175 and 176 are connected to the fixing device 33 of the V specification. These fuses 174,...
It is connected to the fuse determination circuit 173 via the aforementioned connector terminal 172b. This fuse determination circuit 17
3 is connected to the control circuit 133, and the corresponding fuse 174 is connected under the control of the control circuit 133.
,... or check the status of fuse 174,...
It is used to fuse and cut.

The fuse determination circuit 173 is connected to the inverter 191.195.
．． 196, buffers 192, 193, 194, npn transistors Ta, Tb, Tc.

It is composed of resistors R20, R21, R22, and R23, and diodes D11, D12, DlB, D14, D15, and D16. For example, the control circuit 13
3, when the transistor Tb is turned on, the buffer 19
4, it is determined that the fuse 176 is connected, and the buffer 19
4, it is determined that the fuse 176 is disconnected. The control circuit 133 determines that the fuse 174 is connected when a low level signal is supplied from the buffer 192 when the transistor Tc is turned on, and a high level signal is supplied from the buffer 192. In case,
When it is determined that the fuse 174 is disconnected and a low level signal is supplied from the buffer 193,
If it is determined that the fuse 175 is connected and a high level signal is supplied from the buffer 193, it is determined that the fuse 175 is disconnected.

The control circuit 133 also includes transistors Ta,
, Tb, the current due to the +24V power supply voltage flows through the resistor R20, the transistor Ta, and the diode D.
I2, fuse 175, and transistor Tb. As a result, the fuse 176 is blown.

The control circuit 13-3 also includes a transistor Ta.
, Tc, the current due to the +24V power supply voltage flows through the resistor R20, the transistor Ta, and the diode D.
13, fuse 175, and transistor Tc. As a result, the fuse 175 is blown.

The control circuit 133 also includes a transistor Ta5.
By turning on Tc, a current due to the +24V power supply voltage flows through resistor R20, transistor Ta, and diode D1.
2, fuse 174, and transistor Tc. As a result, the fuse 174 is blown.

Further, as shown in FIG. 16, when the connection between the fuse 176 and the fuse 174 is determined, the control circuit 133 determines the setting of the new 100 series fixing device 33, and determines that only the fuse 174 is connected. 100
Determine the setting of the fuser 33 of the old model of the system and set the fuse 17.
6 and fuse 175, the setting of the new fixing device 33 of the 200 series is determined, and the fuse 175 is connected.
If it is determined that only one fuse is connected, the settings of the old 200 series fixing device 33 are determined, and which fuse 174,...
・If the connection of fuse 1 is also not determined, or
If it is determined that only 76 is connected, the setting of the fixing device 33 that has reached the end of its life or requires replacement is determined.

Next, the initial operation when the power is turned on in the above configuration will be explained with reference to the flowchart shown in FIG. 17. For example, now the power switch 68 is turned on. Then, the control circuit 133 reads the setting state of the input voltage changeover switch 70. As a result, depending on the setting state of the input voltage selector switch 70, 100V, 120V
V.

The voltage specification of 220V is read. Next, the control circuit 133 reads the status of the fuses 174, . . . in the fixing device 33. That is, transistor Ta is turned off, transistor Tb5Tc is turned on,
The states of the fuses 174, . . . are read through the buffers 192, 193, 194. As a result, the control circuit 133 compares the operating voltage of the image forming apparatus and the voltage specification of the fixing device 33, and if there is a mismatch, displays this using the display circuit 134, and the driver 152
By turning off 5SR 165, no AC input voltage is supplied to heater lamp 40. This can prevent fixing failure or thermal melting of the fixing device 33 caused by a difference between the operating voltage of the image forming apparatus and the voltage specifications of the fixing device 33.

Further, when the operating voltage of the image forming apparatus and the voltage specification of the fixing device 33 match, the control circuit 133 determines whether the fuse is new or old based on the connection state of the fuses 174, . . . . If the product is new, the control circuit 133 clears the counter for life management of the fixing device in the memory 153, and clears the transistors Ta and Tb in the fuse determination circuit 173.
Turn on.

As a result, a power supply voltage of +24V is applied to the fuse 176, and the fuse 176 is blown (cut). Next, if the fuse 176 is cut, the control circuit 133 uses the display circuit 134 to display the lifespan of the fixing device 33, and if the fuse 176 is not cut, the lifespan of the fixing device 33 is displayed in the memory 153. The count value of the management counter is read and it is determined whether or not the life of the fixing device 33 has exceeded 80,000 sheets. If the life has exceeded 80,000 sheets, the transistors Ta and Tc are turned on. As a result, the power supply voltage +
24V is applied to the fuse 174 or 175 and it is fused (cut). Next, the control circuit 133 uses the display circuit 134 to display that the fixing device 33 has reached the end of its life. If the lifespan has not been exceeded, the control circuit 133 ends the initial operation.

In this way, the operating voltage of the image forming apparatus and the voltage specifications of the fixing device 33 can be compared using the fuses 174 and 175 for life management.
Even if a fixing device 33 with a different voltage specification is inserted by mistake, the fixing device 33 will not be energized, and defective fixing or thermal melting of the fixing device 33 can be prevented.

In addition, by providing a fuse for distinguishing new from old and a fuse for discriminating lifespan inside the fixing device 33, the fixing device 33
3 lifespan can be easily and reliably managed. Management using these two fuses can be applied not only to the fixing device but also to drum devices and developing devices that require life management and destination management.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide an image forming apparatus that can accurately manage the life of a fixing device and the like with a simple configuration.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram schematically showing the overall configuration, FIG. 2 is an external perspective view of the image forming apparatus, and FIG. 3 is a vertical cross-sectional side view of the image forming apparatus. figure,
Fig. 4 is a partial vertical side view of the image forming apparatus, Fig. 5 is an external perspective view of the image forming apparatus with the top cover open, and Fig. 6 explains the connection relationship between the apparatus main body and the AC power cord. Figure 7 is a perspective view showing the configuration of the AC power cord, Figure 8 is a plan view showing the configuration behind the main body of the device, and Figure 9 is the state of supply of the AC input terminal to the heater lamp. 10 is an electric circuit diagram showing the configuration of the overvoltage protection device, and FIG. 11 shows the lighting state of the display corresponding to the setting position of the input terminal selector switch, the operating voltage range,
A diagram for explaining the state of the bidirectional thyristor, FIG. 12 is a diagram showing signal waveforms of important parts in the overvoltage protection circuit, and FIGS. 13 and 14 are diagrams for explaining the connection section provided at the bottom of the fixing device. Fig. 15 is a plan view showing the configuration of fuses and fuse determination circuits in the fixing device.
FIG. 6 is a diagram for explaining a voltage specification determination method for the fixing device, and FIG. 17 is a flowchart for explaining the initial operation when the power is turned on. 33... Fixing device, 68... Main switch, 7
0... Input voltage selection switch, 71... Blue display, 72... Red display, 133... Control circuit, 134... Display circuit, 152... Driver, 153... Memory , 161... Overvoltage protection device, 162... Overvoltage protection circuit, 163... Internal circuit, 172... Connecting section, 173... Fuse determination circuit, 174-176... Fuse.

Claims (3)

[Claims] (1) In an image forming apparatus in which the fixing device is configured to be detachable and performs image formation, a first fuse for distinguishing old from new and a second fuse for life management are provided in the fixing device, and when the power is turned on, , determining means for determining whether the fixing device is old or new based on the state of the first fuse, and determining the lifespan of the fixing device based on the state of the second fuse; and a new fixing device is determined by the determining means. a first cutting device for cutting a first fuse in the fixing device; and a counting device for counting the number of sheets fixed by the fixing device after the first cutting device cuts the first fuse. And, if the counted value by this counting means exceeds a predetermined number,
An image forming apparatus comprising: second cutting means for cutting a second fuse in the fixing device. (2) In an image forming apparatus in which fixing devices with different operating voltage ranges are removably configured and perform image formation, a plurality of fuses for life management indicating operating voltage ranges are provided in the fixing device, and the fixing device a determining means for determining the operating voltage range of the fixing device using a fuse in the fuser; an indicating means for indicating the operating voltage range of the fixing device; and an operating voltage range determined by the indicating means and an operating voltage range determined by the determining device. 1. An image forming apparatus comprising: a determining means for determining whether or not the conditions are met. (3) In an image forming apparatus in which fixing devices with different operating voltage ranges are detachable and form images, a plurality of fuses for life management indicating operating voltage ranges are provided in the fixing device to adjust the power supply voltage. an output means for outputting an output; a determining means for determining an operating voltage range of the fixing device using a fuse in the fixing device; an indicating means for indicating an operating voltage range of the fixing device; and an operating voltage range determined by the indicating means and the above. determining means for determining whether or not the operating voltage ranges match the determining means; and if the determining means determines that the operating voltage ranges match, supplying the output voltage from the output means to the fixing device. An image forming apparatus comprising: a supply means;