JP5929262B2 - Image forming apparatus and inspection method thereof - Google Patents

Description

  The present invention relates to an image forming apparatus and an inspection method therefor, and more particularly, to an inspection technique for electrical connection between a mounting unit on which an image forming unit is mounted and the image forming unit in the image forming apparatus.

  2. Description of the Related Art Conventionally, as an inspection technique for electrical connection between a mounting unit on which an image forming unit is mounted and the image forming unit, for example, one described in Patent Document 1 is known. In the prior art document, in order to inspect a plurality of high-voltage power supplies, a technique is disclosed in which one of the high-voltage power supplies is set as an output side and the other is set as a load side, thereby simultaneously determining a connection state of a plurality of high-voltage terminals. Yes.

JP 2010-060723 A

  However, if the high-voltage power supply requires a monitor for each high-voltage, or the high-voltage power supply with a large number of soft control channels that need feedback in the control circuit, the above technology can be easily adopted, but there is no need for feedback, and miniaturization can be achieved. There is a disadvantage that it is difficult to adopt in a high-voltage power supply having many hardware control configurations.

  The present invention provides a technique that can suitably perform an electrical connection inspection between a mounting portion and an image forming portion while reducing the size of a high-voltage power supply.

  An image forming apparatus disclosed in the present specification includes an image forming unit related to image formation, a mounting unit on which the image forming unit is mounted, and an inspection jig is mounted instead of the image forming unit, Each has a first output generation circuit for generating an electrical output and a maintenance circuit for maintaining the electrical output generated by the first output generation circuit at a predetermined value, and the electrical output of each predetermined value is attached to the mounting A plurality of first application units that are applied to the image forming unit mounted on the unit, a second output generation circuit that generates an electrical output, and a current that is the electrical output generated by the second output generation circuit is detected A detection circuit for generating a current detection signal to be applied, and applying a predetermined value of electrical output to the image forming unit mounted on the mounting unit, and forming the image on the first applying unit. Control to apply the electric output of the predetermined value to the part. A control unit that sends a signal to the first output generation circuit of the first application unit, and the control unit uses the control signal to inspect the test voltage by the first output generation circuit of the first application unit. The inspection circuit generates the current detection signal based on the inspection current when the inspection voltage is applied to the second application unit via the inspection jig mounted on the mounting unit. A current detection process; a current calculation process for calculating a current value of the inspection current flowing through the detection circuit based on the current detection signal; and the current value calculated by the current calculation process is less than a predetermined value, At least one of the electrical connection between the first application unit that has generated the inspection voltage and the image forming unit and the electrical connection between the second application unit and the image forming unit is normally performed. Absent It executes a determination processing for determining.

  According to this configuration, in the multi-channel output high-voltage power supply, only one output unit (second application unit) having a feedback circuit (detection circuit) that supplies a feedback signal (current detection signal) to the control unit is provided. In the configuration in which the output unit (first application unit) does not include a detection circuit, by appropriately setting a predetermined value of the detection current value, each of the application unit and the inspection jig is used to connect the mounting unit and the image forming unit. Connection inspection can be suitably performed. Therefore, it is possible to suitably perform the connection inspection between the mounting portion and the image forming portion while reducing the size of the multi-channel output high-voltage power source.

In the image forming apparatus, the control unit may determine in the determination process that any of the electrical connections is normally performed when the current value of the inspection current is equal to or greater than the predetermined value. .
According to this configuration, when the current value of the inspection current is equal to or greater than the predetermined value, it can be reliably determined that any electrical connection is normally performed.

In the image forming apparatus, the control unit may simultaneously generate the inspection voltage by the first output generation circuits of the plurality of first application units in the inspection current detection process.
According to this configuration, the detection time can be shortened by generating the inspection voltage at the same time as compared with the case where the inspection voltage is generated and detected individually.

In the image forming apparatus, the control unit may be configured such that, in the determination process, the current value of the inspection current is normally electrically connected to the image forming units of all of the plurality of first application units. If the current value is equal to or greater than the current value, it is determined that the electrical connection between the image forming units of all the first application units and the electrical connection between the second application unit and the image forming units are normally performed. It may be.
According to this configuration, it can be seen that many connection states are normal at one time.

In the image forming apparatus, the control unit sets a predetermined value of the current value of the inspection current that is different for each first application unit, and sets the predetermined value and the current calculation process. Based on the calculated current value, whether or not the electrical connection between the first application unit and the image forming unit that simultaneously generated the inspection voltage is normally performed, and the second application unit and the image forming unit It may be determined whether or not the electrical connection to is normally performed.
According to this configuration, each electrical connection can be determined in detail.
In that case, the said control part may set each predetermined value of the said current value by changing the said test | inspection voltage as said electric output of each 1st application part.
According to this configuration, the setting of each predetermined value with a different current value for each first application unit changes the resistance value provided in the current path corresponding to each first application unit of the inspection jig. However, the change of the output voltage is more flexible in setting each predetermined value than that in the case. That is, the change is possible in software.

In the image forming apparatus, the control unit may set the inspection voltage as the electrical output of each of the first application units so that the current detection signal is within an allowable range. .
According to this configuration, even if the output voltage is configured by an application unit in which positive and negative are mixed, it is possible to suppress the failure of the control unit.

  In the image forming apparatus, the plurality of first application units generate voltage outputs having the same polarity as the electrical output, and the second application unit includes the plurality of first application units as the electrical output. May generate voltage outputs of different polarities.

According to this configuration, the current detection signal can be easily set within the allowable range, so that it is possible to suppress the failure of the control unit.
In this case, the image forming unit includes a plurality of transfer units and a belt cleaning unit, and the plurality of first application units are a plurality of transfer voltage application units that apply transfer voltages to the plurality of transfer units, The second application unit may be configured to be a belt cleaning voltage application unit that applies a belt cleaning voltage to the belt cleaning unit.

  According to this configuration, since a negative voltage is normally used as the transfer voltage and a positive voltage is used as the belt cleaning voltage, compatibility of the connection inspection is good.

  An inspection method for an image forming apparatus disclosed in this specification includes an image forming unit that is detachably mounted for image formation, and a mounting unit that can be mounted with an inspection jig instead of the image forming unit. Each has a first output generation circuit for generating an electrical output and a maintenance circuit for maintaining the electrical output generated by the first output generation circuit at a predetermined value, and the electrical output of each predetermined value is attached to the mounting A plurality of first application units that are applied to the image forming unit mounted on the unit, a second output generation circuit that generates an electrical output, and a current that is the electrical output generated by the second output generation circuit is detected And a second application unit that applies a predetermined value of electrical output to the image forming unit mounted on the mounting unit. Electrical connection between the image forming unit and the image forming unit An image forming apparatus inspection method for inspecting whether or not the inspection is always performed, wherein an inspection voltage is generated by the step of attaching the inspection jig to the attachment portion and the first output generation circuit of the first application portion. Current detection signal that causes the detection circuit to generate the current detection signal based on the inspection current when the inspection voltage is applied to the second application unit via the inspection jig mounted on the mounting unit. A current calculating step of calculating a current value of the inspection current flowing in the detection circuit based on the current detection signal, and the inspection voltage when the current value calculated by the current calculating step is less than a predetermined value. At least one of the electrical connection between the first application unit and the image forming unit that has generated the image and the electrical connection between the second application unit and the image forming unit is not normally performed. And a determination processing step of determining the.

  According to the image forming apparatus of the present invention, the electrical connection inspection between the mounting portion and the image forming portion can be suitably performed while reducing the size of the high-voltage power supply.

1 is a schematic cross-sectional view illustrating an internal configuration of a printer according to an embodiment of the invention. Schematic circuit diagram showing an example of electrical connection inspection Flow chart showing outline of electrical connection inspection Table showing the relationship between the current detection value and the inspection result Schematic circuit diagram showing another example of electrical connection inspection

<Embodiment>
One embodiment will be described with reference to FIGS.
1. Overall Configuration of Printer FIG. 1 is a side sectional view showing a schematic configuration of a printer 10 (an example of an image forming apparatus) according to the present embodiment. In the following description, the left side in FIG. The printer 10 is an LED color printer that forms a color image with four colorants (black K, yellow Y, magenta M, and cyan C). Hereinafter, when distinguishing each component for each color, It is assumed that K (black), Y (yellow), M (magenta), and C (cyan) meaning each color are added to the end of the reference numerals of the component parts. Further, the printer 10 is not limited to an LED color printer, and may be, for example, a laser color printer, a facsimile machine, a so-called multi-function machine having a printer function and a reading function (scanner function), or the like.

  The printer 10 includes a main body casing 3, and a supply tray 7 on which sheets 5 as recording media are loaded is provided at the bottom of the main body casing 3. An upper cover 3A is provided on the upper surface of the main casing 3 so as to be openable and closable around the rear end.

  A paper feed roller 9 is provided above the front end of the supply tray 7, and the uppermost paper 5 stacked in the supply tray 7 is sent out to the registration roller 11 as the paper feed roller 9 rotates. The registration roller 11 carries out the skew correction of the paper 5 and then transports the paper 5 onto the belt unit 15 of the image forming unit 13.

  The image forming unit 13 related to image formation includes a belt unit 15, an exposure unit 17, a process unit 19, a fixing unit 21, a belt cleaning device 28, and the like.

  The belt unit 15 (an example of an “image forming unit”) includes a pair of front and rear belt support rollers 23 and a belt 25. When the rear belt support roller 23 is driven to rotate, the belt 25 circulates in a clockwise direction on the paper surface, and the paper 5 on the upper surface of the belt 25 is conveyed backward. Further, on the inner side of the belt 25, transfer rollers 29 are provided at positions opposed to respective photosensitive drums 27 of the process unit 19, which will be described later, with the belt 25 interposed therebetween. The belt unit 15 has TRCC1 to TRCC4 terminals for receiving transfer voltages TRCC1 to TRCC4 applied to the respective transfer rollers 29. The belt unit 15 is mounted on a belt unit mounting portion 15c installed on a main body frame (not shown). The belt unit mounting portion 15c is provided with electrode terminals TK1 to TC1 at positions corresponding to the respective TRCC1 to TRCC4 terminals. The electrode terminals TK1 to TC1 are connected to the transfer voltage generation circuits 70K to 70C via the voltage application lines LK1 to LC1 (see FIG. 2).

  The exposure unit 17 includes four LED units 17 corresponding to the respective colors. Each LED unit 17 has an LED head 18 at its lower end, and its upper end is supported on the lower surface of the upper cover 3A by a predetermined means (not shown). The LED head 18 has a plurality of light emitting units made of LEDs arranged in the left-right direction. Each light emitting unit is controlled to emit light based on the image data to be formed, whereby the light emitted from each light emitting unit is irradiated onto the surface of the photosensitive drum 27, and the surface is exposed.

  The process unit 19 includes a plurality (four in this embodiment) of process cartridges (an example of an “image forming unit”) 33 corresponding to the four colors, and a mounting frame 31 on which the process cartridges 33 are mounted. The process cartridge 33 includes a monochrome cartridge 33K and color cartridges 33Y, 33M, and 33C.

  The monochrome cartridge 33K has a photosensitive drum 27, a scorotron charger 37, a drum cleaning roller 34, and a drum cleaning shaft 35, each of which is covered with a positively chargeable photosensitive layer at the lower part of the cartridge frame 32 and is a high resistance body. A developing cartridge 40K on the upper side of the cartridge frame 32.

  A roller voltage DCLNA, which is a high voltage, is applied to the drum cleaning roller 34 (an example of an “image forming unit”), and the toner remaining on the photosensitive drum 27 is collected by the application of the roller voltage DCLNA.

  The drum cleaning shaft 35 is made of a conductive metal, and the paper dust on the cleaning roller 34 is removed by applying a shaft voltage DCLNB that is higher than the roller voltage DCLNA. That is, the cleaning shaft 35 removes paper dust mixed in the main body casing (housing) 3 using the shaft voltage DCLNB.

  Normally, the toner is charged positively and the paper dust is negatively charged. Therefore, the toner and the paper dust are individually removed from the photosensitive drum 27 using the difference in the polarity of charging. During printing, a negative voltage, for example, a roller voltage DCLNA (−) of −400 V is applied to the cleaning roller 34 to collect only the toner from the photosensitive drum 27 onto the cleaning roller 34. During printing, a positive voltage, for example, a roller voltage DCLNA (+) of 600V is applied to the cleaning roller 34, and a shaft voltage DCLNB of 700V is applied to the cleaning shaft 35. At this time, the paper dust is collected by the cleaning shaft 35 via the cleaning roller 34. The toner is discharged onto the photosensitive drum 27, and then adhered to the surface of the belt 25 and collected by the belt cleaning device 28.

  The belt cleaning device 28 (an example of an “image forming unit”) includes a belt cleaning roller 28a and a belt cleaning shaft 28b. By applying the belt cleaning roller voltage BCLN to the belt cleaning roller 28a, the toner attached to the surface of the belt 25 is collected via the belt cleaning roller 28a and the belt cleaning shaft 28b. The cleaning device 28 has a BCLN terminal for receiving the belt cleaning roller voltage BCLN. The cleaning device 28 is mounted on a cleaning device mounting portion 28c installed on a main body frame (not shown).

  The monochrome cartridge 33K also includes a CHG terminal that receives the charging voltage CHG, a GRID terminal that receives the grid voltage GRID, a DEV terminal that receives the development bias DEV, a DCLNA terminal that receives the roller voltages DCLNA (+) and DCLNA (−), and a shaft voltage. A DCLNB terminal for receiving DCLNB is provided.

  On the other hand, each of the color cartridges 33Y, 33M, and 33C includes a photosensitive drum 27 and a scorotron charger 37 having a grid 37a and a cleaning roller 34 at the lower part of the cartridge frame 32, and each developing cartridge above the cartridge frame 32. Includes 40Y, 40M, and 40C.

  Each of the color cartridges 33Y, 33M, and 33C has a CHG terminal, a GRID terminal, a DEV terminal, and a DCLNA terminal.

  Each developing cartridge 40 is detachably attached to the cartridge frame 32 of each process cartridge 33. Then, the developing cartridge 40 or the process cartridge 33 is replaced by opening the upper cover 3A, or a paper jam removal process (jam process) is performed with the process cartridge 33 removed.

  Each developing cartridge 40 includes a toner storage chamber 42 that stores toner of each color, which is a developer (colorant), in an upper portion inside a box-shaped casing, and a supply roller 41, a developing roller 43, and the like below. ing.

  The toner discharged from the toner storage chamber 42 is supplied to the developing roller 43 by the rotation of the supply roller 41, and is positively frictionally charged between the supply roller 41 and the developing roller 43. Further, the toner supplied onto the developing roller 43 is sufficiently charged as a developing bias is applied, and is carried on the developing roller 43 as a thin layer having a constant thickness.

  At the time of image formation, the photosensitive drum 27 is rotationally driven, and accordingly, the surface of the photosensitive drum 27 is uniformly positively charged by the charger 37. The positively charged portion is exposed by high-speed scanning of light from the LED head 18, and an electrostatic latent image corresponding to an image to be formed on the paper 5 is formed on the surface of the photosensitive drum 27.

  Next, when the developing roller 43 is rotated and the positively charged toner carried on the developing roller 43 comes into contact with the photosensitive drum 27 so as to face the surface of the photosensitive drum 27, the static charge is formed. The electric latent image is supplied. As a result, the electrostatic latent image on the photosensitive drum 27 is visualized, and the surface of the photosensitive drum 27 carries a toner image with toner attached only to the exposed portion.

  Thereafter, the toner image carried on the surface of each photosensitive drum 27 is transferred to the transfer roller while the sheet 5 conveyed by the belt 25 passes through each transfer position between the photosensitive drum 27 and the transfer roller 29. The images are sequentially transferred onto the paper 5 by a negative transfer voltage TRCC applied to the paper 29. The sheet 5 having the toner image transferred thereon is then conveyed to the fixing unit 21.

  The fixing unit 21 includes a heating roller 49 having a heat source and a pressure roller 51 that presses the paper 5 toward the heating roller 49, and heat-fixes the toner image transferred onto the paper 5 on the paper surface. The sheet 5 thermally fixed by the fixing unit 21 is conveyed upward and discharged onto a discharge tray 53 provided on the upper surface of the main body casing 3.

  Further, a control board 50 is provided in the casing 3. The control board 50 controls the overall operation of the printer 10.

  The mounting frame 31 to which each process cartridge 33 is mounted is provided with a cartridge mounting portion (corresponding to a “mounting portion”) (31K, 31Y, 31M, 31C) corresponding to each process cartridge 33. Yes. Inside the cartridge mounting portion 31K, electrodes (not shown) for applying each voltage are provided at positions where they abut against the respective terminals of the monochrome cartridge 33K. Similarly, electrodes (not shown) for applying voltages are provided inside the cartridge mounting portions (31Y, 31M, 31C) at positions where they abut against the terminals of the color cartridges 33Y, 33M, 33C. Is provided.

2. Configuration of High Voltage Circuit Next, the high voltage circuit will be described with reference to FIG. A high voltage circuit (high voltage power supply) 60 is provided on the control board 50 and is provided in the printer 10 such as a transfer roller 29, a cleaning roller 34, a cleaning shaft 35, a charger 37, a developing roller 43, and a belt cleaning roller 28a. A plurality of high voltages to be applied to each electrical load is generated.

  FIG. 2 shows a transfer voltage generation circuit (corresponding to a transfer voltage application unit) 70K to 70C that generates transfer voltages TRCC1 to TRCC4 to be applied to each transfer roller 29 among a plurality of high voltages, and a belt cleaning roller 28a. Only a belt cleaning voltage generating circuit (corresponding to a belt cleaning voltage applying unit) 80 for generating a belt cleaning voltage BCLN to be applied to is shown. The configuration of the transfer voltage generation circuits 70Y to 70C of the transfer roller 29 corresponding to the color cartridges 33Y to 33C is the same as that of the transfer voltage generation circuit 70K of the transfer roller 29 corresponding to the monochrome cartridge 33K. Details of the configuration are omitted, and description thereof is omitted.

  The high voltage circuit 60 is roughly composed of a CPU (an example of a “control unit”) 61, a transfer voltage generation circuit (an example of a “first application unit”) 70K to 70C, and a belt cleaning voltage generation circuit (a “second application unit”). Example) 80 is included. The CPU 61 controls the voltage generation circuits 70 and 80 according to a predetermined processing program stored in the ROM 62.

  The transfer voltage generation circuit 70K is, for example, a self-excited high voltage generation circuit, and includes a reference voltage generation circuit 71, an operational amplifier IC1, a transistor Tr1, a transformer T1, a diode D1, a capacitor C1, and voltage dividing resistors R1 and R2. The transfer voltage generation circuit 70K generates a transfer voltage TRCC1 to be supplied to the transfer roller 29 corresponding to the monochrome cartridge 33K. The transfer voltage TRCC1 is a negative high voltage. The transfer voltage generation circuit 70K is a voltage generation circuit having a hardware control configuration in which feedback regarding output is not performed to the CPU 61.

  The reference voltage generation circuit 71 generates a reference voltage Vth according to a PWM (pulse width modulation) signal from the PWM1 port of the CPU 61, and supplies the reference voltage Vth to the non-inverting input of the operational amplifier IC1.

  On the other hand, the divided voltage Vd by the voltage dividing resistors R1 and R2 is input to the inverting input of the operational amplifier IC1. The operational amplifier IC1 generates a drive signal Sd1 for driving the primary side of the transformer T1 based on the reference voltage Vth and the divided voltage Vd. One end of the voltage dividing resistor R1 is connected to one end of the secondary winding of the transformer T1, and the other end is connected to the inverting input of the operational amplifier IC1. One end of the voltage dividing resistor R2 is connected to the inverting input of the operational amplifier IC1, and the other end is connected to the ground.

  The drive signal Sd1 is supplied to the base of the transistor Tr1, and the base current of the transistor Tr1 is controlled by the drive signal Sd1, whereby the secondary voltage of the transformer T1, that is, the transfer voltage TRCC1 is generated. At this time, the operational amplifier IC1 operates so as to eliminate the difference between the reference voltage Vth and the divided voltage Vd, and the current I1 flowing through the voltage dividing resistors R1 and R2 is maintained at a predetermined value by the operation. That is, the transfer current by applying the transfer voltage TRCC1 to the transfer roller 29 is maintained at a predetermined value.

  The diode D1 and the capacitor C1 rectify and smooth the secondary side voltage of the transformer T1 to generate a DC voltage transfer voltage TRCC1.

  Here, the transfer current is an example of “electrical output”, and the reference voltage generation circuit 71, the operational amplifier IC1, and the voltage dividing resistors R1 and R2 constitute a “sustain circuit”, and includes a transistor Tr1, a transformer T1, a diode D1, and The capacitor C1 constitutes a “first output generation circuit”. In other words, in the present embodiment, the transfer voltage generation circuit 70K is subjected to constant current control. Note that the transfer voltage generation circuit 70K is not limited to this, and the transfer voltage generation circuit 70K may be controlled at a constant voltage. In this case, the transfer voltage TRCC1 corresponds to “electric output”.

  The belt cleaning voltage generation circuit (hereinafter referred to as “BCLN generation circuit”) 80 is, for example, a self-excited high voltage generation circuit similar to the transfer voltage generation circuit 70K, and includes a drive circuit 81, a transistor Tr2, a transformer T2, and a diode D2. , A capacitor C2, and a current detection circuit (an example of a “detection circuit”) 82. The transistor Tr2, the transformer T2, the diode D2, and the capacitor C2 constitute a “second output generation circuit”. The BCLN generation circuit 80 generates a belt cleaning voltage BCLN for the belt cleaning roller 28a. The belt cleaning voltage BCLN is a positive high voltage. The BCLN generation circuit 80 is a voltage generation circuit having a software control configuration in which feedback regarding the output is made to the CPU 61.

  The drive circuit 81 generates a drive signal Sd2 for driving the primary side of the transformer T2 in accordance with the PWM signal from the PWM5 port of the CPU 61.

  The drive signal Sd2 is supplied to the base of the transistor Tr2, and the base current of the transistor Tr2 is controlled by the drive signal Sd2, whereby the secondary voltage of the transformer T2, that is, the belt cleaning voltage BCLN is generated. At this time, the CPU 61 controls the pulse width of the PWM signal based on the current detection signal Sid from the current detection circuit 82, thereby setting the BCLN generation circuit 80 so that the belt cleaning voltage BCLN or the belt cleaning current becomes constant. Control.

  The diode D2 and the capacitor C2 rectify and smooth the secondary voltage of the transformer T2 to generate the belt cleaning voltage BCLN.

  Current detection circuit 82 includes resistors R3 and R4. One end of the resistor R3 is connected to the + 5V voltage and one end of the secondary winding of the transformer T2, and the other end is connected to the A / D port of the CPU 61 and one end of the voltage dividing resistor R4. The other end of the resistor R4 is connected to the ground. The current detection signal Sid is a signal for detecting the current Id flowing through the resistor R4, and is input to the A / D port as a voltage value at a connection point between the resistor R3 and the resistor R4.

  The CPU 61 receives the current detection signal Sid from the current detection circuit 82 and, based on the current detection signal Sid, outputs a PWM signal for causing the BCLN generation circuit 80 to apply a belt cleaning voltage BCLN having a predetermined value to the belt cleaning roller 28a. 81.

  That is, the CPU 61 receives the current detection signal Sid, and calculates a current value BCLN-FB from the voltage value of the current detection signal Sid and the resistance value of the resistor R4. Then, the CPU 61 controls the pulse width of the PWM signal based on the current value BCLN−FB so that the belt cleaning voltage BCLN becomes a predetermined value.

3. Next, referring to FIG. 2, whether each high voltage generated by the high voltage circuit 60 is applied to each mounting portion of the printer 10 via each corresponding voltage application line. The inspection jig 100 used for inspecting the above will be described. The inspection jig 100 shown in FIG. 2 includes a jig 100a corresponding to the belt unit mounting portion 15c, a jig 100b corresponding to the cleaning device mounting portion 28c, and a connection line Lcn for connecting the jigs.

  Jig 100a includes common line Lcom and resistors Rj1 to Rj4 connected in parallel to common line Lcom, and jig 100b includes only jumper line Lj. The resistors Rj1 to Rj4 are connected between the connection terminals TJ1 to TJ4 and the common line Lcom. Jumper line Lj is connected to connection terminal TJBC and connection line Lcn, and connection line Lcn is connected to common line Lcom. The connection terminals TJ1 to TJ4 are in contact with the connection terminals TK1 to TC1 provided on the belt unit mounting portion 15c in a state where the jig 100a is mounted on the belt unit mounting portion 15c. Further, the connection terminal TJBC comes into contact with the connection terminal TBC1 provided on the cleaning device mounting portion 28c in a state where the jig 100b is mounted on the cleaning device mounting portion 28c.

  In the present embodiment, the example in which the inspection jig 100 is configured to be separated into the jig 100a and the jig 100b is shown, but the present invention is not limited thereto. For example, when the formation positions of the connection terminals TK1 to TC1 and the connection terminal TBC1 are close in the main body casing 3, the inspection jig 100 can be configured as a single jig. In this case, the connection line Lcn and the like are not necessary, and the configuration of the inspection jig 100 can be simplified.

4). Next, referring to FIG. 3 and FIG. 4, each high voltage generated by the high voltage circuit 60 passes through the corresponding voltage application lines LK <b> 1 to LC <b> 1 and LBC <b> 1. A method for inspecting whether or not the image forming unit, which is each electric load, is normally applied by using the inspection jig 100 will be described. In other words, a method for inspecting whether or not the electrical connection between the mounting portion of the image forming portion and the image forming portion is normally performed using each high voltage generation circuit and the inspection jig 100 will be described.

  FIG. 3 is a flowchart showing an outline of the inspection method. FIG. 4 is a table showing the relationship between the detected current value (feedback current) and connection determination of the high voltage generation circuit (high voltage channel ch). It is assumed that the table shown in FIG. 4 is stored in the ROM 62 as table data, for example.

  In the electrical connection inspection method, first, the inspection jig 100 is mounted on the mounting portion. Specifically, the jig 100a is mounted on the belt unit mounting portion 15c, and the jig 100b is mounted on the cleaning device mounting portion 28c.

  Next, the CPU 61 is operated in accordance with a predetermined inspection program. For example, a PMW having a DUTY ratio (pulse width) of 28% such that a current of 5 μA is detected by the current detection circuit 82 with the transfer voltage generation circuit 70K (ch1) alone. The signal P1 is generated, the PMW signal P1 is supplied to the transfer voltage generation circuit 70K, and the transfer voltage generation circuit 70K is caused to generate the inspection voltage TRCC1 (step S10).

  Similarly, the CPU 61 generates a PMW signal P2 having a DUTY ratio of 34% such that a current of 7 μA is detected by the current detection circuit 82 by the transfer voltage generation circuit 70Y (ch2) alone, and generates a transfer voltage of the PMW signal P2. The transfer voltage generation circuit 70Y is supplied to the circuit 70Y to generate the inspection voltage TRCC2 (step S20).

  Further, the CPU 61 generates the PMW signal P3 having a DUTY ratio of 42% so that the current of 10 μA is detected by the current detection circuit 82 by the transfer voltage generation circuit 70M (ch3) alone, and the PMW signal P3 is transferred to the transfer voltage generation circuit. Then, the transfer voltage generation circuit 70M is caused to generate the inspection voltage TRCC3 (step S30).

  Further, the CPU 61 generates a PMW signal P4 having a DUTY ratio of 46% so that a current of 14 μA is detected by the current detection circuit 82 by the transfer voltage generation circuit 70C (ch4) alone, and the PMW signal P4 is transferred to the transfer voltage generation circuit. Then, the transfer voltage generation circuit 70C generates the inspection voltage TRCC4 (step S40). The generated inspection voltages TRCC1 to TRCC4 are applied to the BCLN generation circuit 80 via the resistors Rj1 to Rj4 of the inspection jig 100.

  At that time, currents I1 to I4 corresponding to the inspection voltages TRCC1 to TRCC4 flow through paths of the transfer voltage generation circuit 70, the ground, the BCLN generation circuit 80, and the inspection jig 100, respectively. Specifically, each of the currents I1 to I4 includes the secondary coil of the transformer T1 of the transfer voltage generation circuit 70, the voltage dividing resistors R1 and R2, the ground, the resistor R4 of the BCLN generation circuit 80, the secondary coil of the transformer T2, and a diode. D2, the inspection jig 100, the diode D1 of the transfer voltage generation circuit 70, and the secondary coil of the transformer T1 flow in this order (see arrows in FIG. 2). At that time, voltage generation by the BCLN generation circuit 80 is stopped. That is, the BCLN generation circuit 80 is used only as a path for each of the currents I1 to I4 and a current detection circuit.

  Note that the relationship between each DUTY ratio and the detected current is determined in advance by experiments or the like. The test voltages TRCC1 to TRCC4 are generated almost simultaneously, and a test current Id that is a combined current of the currents I1 to I4 flows through the resistor R4 of the BCLN generation circuit 80.

  As described above, in this embodiment, the CPU 61 changes the output voltages (inspection voltages) TRCC1 to TRCC4 as the electrical outputs of the transfer voltage generation circuits 70K to 70C, specifically, the DUTY of the PMW signal. Each predetermined value of the current value is set by changing the ratio. At this time, the output voltage TRCC1 to TRCC4, that is, the DUTY ratio of each PMW signal is set so that the value BCLN-FB of the current detection signal Sid falls within the allowable range. Therefore, it can suppress that CPU61 breaks down.

  It should be noted that the setting of the predetermined values of the different current values for the transfer voltage generation circuits 70K to 70C corresponds to the transfer voltage generation circuits 70K to 70C of the inspection jig 100 with the inspection voltages TRCC1 to TRCC4 being the same. This is also possible by changing the resistance values of the resistors Rj1 to Rj4 provided in the current path. However, changing the test voltages TRCC1 to TRCC4 is more flexible and easy to set, as compared to changing the resistance values of the resistors Rj1 to Rj4. That is, it is only necessary to change the setting of the DUTY ratio of the PMW signal, and the change can be made in software.

  Next, in order to stabilize the operation of the transfer voltage generation circuits 70K to 70C, a predetermined standby time, for example, 100 ms is provided (step S50).

  After the standby time, the CPU 61 receives the current detection signal Sid from the current detection circuit 82, and calculates a current value BCLN-FB of the detection current (inspection current) Id based on the current detection signal Sid (step S60).

  Then, it is determined whether or not the current value BCLN−FB is equal to or greater than 36 μA (an example of a predetermined value) that is the total value of the currents I1 to I4 (step S70). When it is determined that the current value BCLN-FB is equal to or greater than 36 μA (step S70: YES), it is determined whether the current value BCLN-FB is less than 40 μA (step S72). When it is determined that the current value BCLN-FB is less than 40 μA (step S72: YES), the electrical connection between the transfer voltage generation circuits 70K to 70C and each of the transfer rollers 29 (hereinafter referred to as “first electrical connection CN1”). And electrical connection between the BCLN generation circuit 80 and the belt cleaning roller 28a (hereinafter referred to as “second electrical connection CN2”), and it is determined that both electrical connections are normally performed.

  If current does not flow normally due to disconnection or the like in any one of the current paths through the inspection jig 100, the total value of the currents I1 to I4, that is, the detected current Id is the current value BCLN−. By not reaching FB. Therefore, when the current value BCLN-FB is 36 μA or more, it can be reliably determined that any electrical connection is normally performed.

  Then, the inspection result to that effect is displayed on, for example, the display device 4a (step S75), the generation of the PWM signals P1 to P4 is stopped, and the operations of the transfer voltage generation circuits 70K to 70C are stopped (step S90). ) End the inspection.

  Further, when it is determined that the current value BCLN-FB is 40 μA or more (step S72: NO), a current exceeding the generation target value flows, and therefore, the high voltage circuit 60 such as the transistor Tr1 of the transfer voltage generation circuit 70 is supplied. It is determined that some trouble has occurred, the fact that the high voltage circuit 60 has failed is displayed on the display device 4a (step S74), and the process proceeds to step S90. That is, in this embodiment, when the current value BCLN-FB is greater than or equal to a predetermined value, an abnormality in the high voltage circuit 60 can also be detected. Note that the processing in steps S72 and S74 may be omitted.

  On the other hand, when it is determined that the current value BCLN-FB is not greater than 36 μA, that is, the current value BCLN-FB is less than 36 μA (step S70: NO), the CPU 61 stores the table data shown in FIG. Referring to FIG. 4, a path (ch) where electrical connection is not normally performed is determined (step S80).

  For example, when the current value BCLN-FB is zero, that is, when the detection current Id is zero, it is determined that the second electrical connection CN2 is not normally performed. Alternatively, it is determined that the second electrical connection CN2 is normally performed and all the first electrical connection CN1 is not normally performed. Alternatively, it is determined that all of the first electrical connection CN1 and the second electrical connection CN2 are not normally performed. That is, in this case, the CPU 61 determines that at least one of the first electrical connection CN1 and the second electrical connection CN2 is not normally performed.

  Further, for example, when the current value BCLN-FB is 5 μA, the second electrical connection CN2 is normally performed, and the first electrical connection CN1 is connected between the transfer voltage generation circuit 70K and the transfer roller 29 (ch1). It is determined that only electrical connection is normally performed (see step S10). That is, in this case, the CPU 61 determines that ch2, ch3, and ch4 are not normally performed in the first electrical connection CN1.

  Further, for example, when the current value BCLN−FB is 12 μA, the second electrical connection CN2 is normally performed, and the first electrical connection CN1 between the transfer voltage generation circuit 70K and the transfer roller 29 (ch1) is set. It is determined that the electrical connection and the electrical connection between the transfer voltage generation circuit 70Y and the transfer roller 29 (ch2) are normally performed (see steps S10 and S20). That is, in this case, the CPU 61 determines that ch3 and ch4 of the first electrical connection CN1 are not normally performed.

  Further, for example, when the current value BCLN-FB is 22 μA, the second electrical connection CN2 is normally performed, and between the first electrical connection CN1 between the transfer voltage generation circuit 70C and the transfer roller 29 (ch4). It is determined that each electrical connection except the electrical connection is normally performed (see steps S10, S20, and S30). That is, in this case, the CPU 61 determines that ch4 is not normally performed in the first electrical connection CN1.

  As described above, when the calculated current value BCLN−FB is less than 36 μA (predetermined value), the CPU 61 correctly establishes at least one of the first electrical connection CN1 and the second electrical connection CN2. Judge that not done.

Then, the determination result is displayed on, for example, the display device 4a (step S85), the generation of the PWM signals P1 to P4 is stopped, and the operations of the transfer voltage generation circuits 70K to 70C are stopped (step S90). End inspection.
In the determination process in step S80, the current value BCLN-FB is assumed to include a predetermined allowable range, for example, an allowable range of “± 0.2 μA”. Therefore, for example, if the current value BCLN-FB is 11.8 μA, it is determined that the connection of ch1 and ch2 is normal, or if the current value BCLN-FB is 22.2 μA, ch1, It is determined that the connection between ch2 and ch3 is normal.

  Thus, in this embodiment, the CPU 61 sets a predetermined current value of the detection current Id that is different for each of the transfer voltage generation circuits 70K to 70C. Then, based on the set predetermined value and the calculated current value BCLN−FB, the transfer voltage generation circuits 70K to 70C that simultaneously generate the inspection voltages TRCC1 to TRCC4 and the transfer rollers 29 are normally connected. It is determined whether or not the electrical connection between the BCLN generation circuit 80 and the belt cleaning roller 28a is normally performed. Thereby, each electrical connection can be determined in detail, ie individually. Note that the voltage values of the inspection voltages TRCC1 to TRCC4 may be the same as or different from the voltage values of the transfer voltages TRCC1 to TRCC4 when the transfer is actually performed.

5. Effects of the Embodiment A plurality of transfer voltage generation circuits 70K having no feedback circuit are set by appropriately setting the current value BCLN-FB (predetermined value) of the detection current Id by the current detection circuit (feedback circuit) 82 of the BCLN generation circuit 80. The electrical connection between ˜70 C and the transfer roller 29 can be inspected. In other words, the electrical connection between a plurality of high voltage generation circuits not having a feedback circuit and the image forming unit can be inspected using a high voltage generation circuit having a single feedback circuit. Therefore, it is possible to suitably perform the electrical connection inspection between the belt unit mounting portion 15c and the transfer roller 29 and between the cleaning device mounting portion 28c and the belt cleaning roller 28a while reducing the size of the high voltage circuit 60. That is, the electrical connection inspection between the mounting portion and the image forming portion can be suitably performed while downsizing the high-voltage power source.

  The electrical connection inspection is performed by causing the transfer voltage generation circuits 70K to 70C to simultaneously generate the inspection voltages TRCC1 to TRCC4. Therefore, the detection time can be shortened compared with the case where the inspection voltages TRCC1 to TRCC4 are individually generated and the transfer voltage generation circuits 70K to 70C are inspected.

  Further, as a plurality of first application units that do not have a feedback circuit (detection circuit) to the CPU 61, transfer voltage generation circuits 70K to 70C that generate negative voltage outputs TRCC1 to TRCC4 are used. Further, a BCLN generation circuit 80 that generates a positive voltage output BCLN is used as the second application unit having the detection circuit. With this configuration, the inspection current Id flows in the same direction. Therefore, the compatibility of the connection inspection is good and the detected current value BCLN-FB is easily set within the allowable range, so that the CPU 61 can be prevented from malfunctioning.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the present embodiment, an example in which the electrical connection inspection is performed by causing the transfer voltage generation circuits 70K to 70C to generate the inspection voltages TRCC1 to TRCC4 at the same time has been described. The inspection voltage TRCC may be generated for each transfer voltage generation circuit 70, the inspection current Id may be individually detected, and the electrical connection inspection of each transfer voltage generation circuit 70 may be performed from the current value.

  In this case, it is not necessary to set a predetermined value of the current value of the inspection current Id that is different for each of the transfer voltage generation circuits 70K to 70C, and the predetermined value of the current value may be the same. That is, the inspection voltages TRCC1 to TRCC4 may be the same while the DUTY ratio of the PMW signal is the same.

  (2) In the present embodiment, as an example of the electrical connection test, as a plurality of first application units that do not have a feedback circuit (detection circuit) to the CPU 61, transfer that generates all negative voltage outputs TRCC1 to TRCC4. Although the example which uses the BCLN generation circuit 80 which produces | generates the positive voltage output BCLN was shown as a 2nd application part which uses the voltage generation circuits 70K-70C and has a detection circuit, it is not restricted to this. For example, as shown in FIG. 5, the plurality of first application units are all charged voltage generation circuits 70A-K to 70A-C that generate positive voltage outputs CHG1 to CHG4, and the second application unit has a negative polarity. Even in the case of the drum cleaning voltage generation circuit 80A-C that generates the roller voltage DCLNA (−), each electrical connection inspection can be performed. At that time, the direction in which the inspection current Id flows is opposite to that in FIG. Further, since the inspection jig 100A is mounted on each cartridge mounting portion (31K, 31Y, 31M, 31C), the configuration of the inspection jig 100A is different from the configuration of the above embodiment, but the equivalent circuits are the same. (See FIG. 5).

  Further, the plurality of first application units that do not have the feedback circuit (detection circuit) to the CPU 61 are not limited to those that generate voltage outputs of the same polarity, and are configured by the first application unit in which the output voltage is mixed. May be. In this case, the CPU 61 may set the output voltage (inspection voltage) of each first application unit so that the current detection signal is within the allowable range. As a result, even if the output voltage is configured by an application unit in which positive and negative are mixed, it is possible to suppress the failure of the CPU 61 (control unit).

  DESCRIPTION OF SYMBOLS 10 ... LED color printer, 15 ... Belt unit, 15c ... Belt unit mounting part, 28a ... Belt cleaning roller, 28c ... Belt cleaning apparatus mounting part, 29 ... Transfer roller, 61 ... CPU, 70K-70C ... Transfer voltage generation circuit, 80 ... Belt cleaning voltage generation circuit, 100, 100A ... Inspection jig

Claims (10)

An image forming unit for image formation;
The image forming unit is mounted, and a mounting unit on which an inspection jig is mounted instead of the image forming unit,
Each has a first output generation circuit for generating an electrical output and a maintenance circuit for maintaining the electrical output generated by the first output generation circuit at a predetermined value, and the electrical output of each predetermined value is attached to the mounting A plurality of first application units that apply to the image forming unit mounted on the unit;
A second output generation circuit that generates an electrical output; and a detection circuit that generates a current detection signal that detects a current that is the electrical output generated by the two-output generation circuit; A second application unit that applies to the image forming unit mounted on the mounting unit;
A control unit that sends a control signal that causes the first application unit to apply the electrical output of the predetermined value to the image forming unit to the first output generation circuit of the first application unit;
The controller is
An inspection voltage is generated by the first output generation circuit of the first application unit using the control signal, and the inspection voltage is applied to the second application unit via the inspection jig attached to the attachment unit. An inspection current detection process for causing the detection circuit to generate the current detection signal based on the inspection current when applied;
A current calculation process for calculating a current value of the inspection current flowing in the detection circuit based on the current detection signal;
When the current value calculated by the current calculation process is less than a predetermined value, electrical connection between the first application unit and the image forming unit that has generated the inspection voltage, and the second application unit and the image formation A determination process for determining that at least one of the electrical connections with the unit is not normally performed , and
In the inspection current detection process, the inspection voltage is simultaneously generated by the first output generation circuit of the plurality of first application units. The image forming apparatus according to claim 1.
The control unit, in the determination process, determines that any of the electrical connections is normally performed when the current value of the inspection current is equal to or greater than the predetermined value. The image forming apparatus according to claim 1 , wherein:
The controller is
In the determination process, when the current value of the inspection current is equal to or greater than a current value when electrical connection with the image forming units of all of the plurality of first application units is normally performed, the plurality of first items. An image forming apparatus that determines that electrical connection between all of the application units with the image forming unit and electrical connection between the second application unit and the image forming unit are normally performed. The image forming apparatus according to claim 3 .
The controller is
A predetermined value of the current value of the inspection current, which is different for each first application unit, is set,
Whether the electrical connection between each image forming unit and the first application unit that has generated the inspection voltage at the same time is normally performed based on the set predetermined value and the current value calculated by the current calculation process And an image forming apparatus that determines whether or not the electrical connection between the second application unit and the image forming unit is normally performed. The image forming apparatus according to claim 4 .
The image forming apparatus, wherein the control unit sets each predetermined value of the current value by changing the inspection voltage as the electrical output of each first application unit. An image forming unit for image formation;
The image forming unit is mounted, and a mounting unit on which an inspection jig is mounted instead of the image forming unit,
Each has a first output generation circuit for generating an electrical output and a maintenance circuit for maintaining the electrical output generated by the first output generation circuit at a predetermined value, and the electrical output of each predetermined value is attached to the mounting A plurality of first application units that apply to the image forming unit mounted on the unit;
A second output generation circuit that generates an electrical output; and a detection circuit that generates a current detection signal that detects a current that is the electrical output generated by the two-output generation circuit; A second application unit that applies to the image forming unit mounted on the mounting unit;
A control unit that sends a control signal that causes the first application unit to apply the electrical output of the predetermined value to the image forming unit to the first output generation circuit of the first application unit;
The controller is
An inspection voltage is generated by the first output generation circuit of the first application unit using the control signal, and the inspection voltage is applied to the second application unit via the inspection jig attached to the attachment unit. An inspection current detection process for causing the detection circuit to generate the current detection signal based on the inspection current when applied;
A current calculation process for calculating a current value of the inspection current flowing in the detection circuit based on the current detection signal;
When the current value calculated by the current calculation process is less than a predetermined value, electrical connection between the first application unit and the image forming unit that has generated the inspection voltage, and the second application unit and the image formation A determination process for determining that at least one of the electrical connections with the unit is not normally performed, and
An image forming apparatus that sets the inspection voltage as the electrical output of each first application unit so that the current detection signal is within an allowable range. The image forming apparatus according to claim 1 , wherein:
The plurality of first application units generate a voltage output having the same polarity as the electrical output,
The image forming apparatus, wherein the second application unit generates a voltage output having a polarity different from that of the plurality of first application units as the electrical output. The image forming apparatus according to claim 7 .
The image forming unit includes a plurality of transfer units and a belt cleaning unit,
The plurality of first application units are a plurality of transfer voltage application units that apply transfer voltages to the plurality of transfer units,
The image forming apparatus, wherein the second application unit is a belt cleaning voltage application unit that applies a belt cleaning voltage to the belt cleaning unit. An image forming unit related to image formation is detachably mounted, a mounting unit on which an inspection jig can be mounted instead of the image forming unit, and a first output generation circuit each generating an electrical output, A maintenance circuit for maintaining the electrical output generated by the first output generation circuit at a predetermined value, and applying a plurality of predetermined electrical outputs to the image forming unit mounted on the mounting unit. A first application unit; a second output generation circuit that generates an electrical output; and a detection circuit that generates a current detection signal that detects a current that is the electrical output generated by the second output generation circuit; In the image forming apparatus including the second application unit that applies the electrical output of the value to the image forming unit mounted on the mounting unit, the electrical connection between each application unit and the image forming unit is normally performed. Inspection method of image forming equipment There is,
Mounting the inspection jig on the mounting portion;
An inspection when an inspection voltage is generated by the first output generation circuit of the first application unit, and the inspection voltage is applied to the second application unit via the inspection jig attached to the attachment unit. An inspection current detection step for causing the detection circuit to generate the current detection signal based on a current;
A current calculation step of calculating a current value of the inspection current flowing through the detection circuit based on the current detection signal;
When the current value calculated by the current calculation step is less than a predetermined value, the electrical connection between the first application unit and the image forming unit that has generated the inspection voltage, and the second application unit and the image formation. A determination processing step of determining that at least one of the electrical connections with the unit is not normally performed;
Only including,
An inspection method for an image forming apparatus, wherein in the inspection current detection step, the inspection voltage is generated simultaneously by the first output generation circuits of the plurality of first application units . An image forming unit related to image formation is detachably mounted, a mounting unit on which an inspection jig can be mounted instead of the image forming unit, and a first output generation circuit each generating an electrical output, A maintenance circuit for maintaining the electrical output generated by the first output generation circuit at a predetermined value, and applying a plurality of predetermined electrical outputs to the image forming unit mounted on the mounting unit. A first application unit; a second output generation circuit that generates an electrical output; and a detection circuit that generates a current detection signal that detects a current that is the electrical output generated by the second output generation circuit; In the image forming apparatus including the second application unit that applies the electrical output of the value to the image forming unit mounted on the mounting unit, the electrical connection between each application unit and the image forming unit is normally performed. Inspection method of image forming equipment There is,
Mounting the inspection jig on the mounting portion;
An inspection when an inspection voltage is generated by the first output generation circuit of the first application unit, and the inspection voltage is applied to the second application unit via the inspection jig attached to the attachment unit. An inspection current detection step for causing the detection circuit to generate the current detection signal based on a current;
A current calculation step of calculating a current value of the inspection current flowing through the detection circuit based on the current detection signal;
When the current value calculated by the current calculation step is less than a predetermined value, the electrical connection between the first application unit and the image forming unit that generated the inspection voltage, and the second application unit and the image formation A determination processing step of determining that at least one of the electrical connections with the unit is not normally performed;
Including
An inspection method for an image forming apparatus, wherein the inspection voltage as the electrical output of each first application unit is set so that the current detection signal is within an allowable range.

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