JP4948309B2 - Connector connection detector - Google Patents

Description

The present invention relates to a connector connection detection equipment which detects the connection of a plurality of connectors.

  Conventionally, signal lines for controlling a plurality of loads respectively disposed at a plurality of locations in the apparatus are connected to a control unit that controls a plurality of loads. For example, in the case of an image forming apparatus, examples of the plurality of loads include a sensor that detects the position of a sheet, a drive motor that conveys the sheet, and an electromagnetic clutch that transmits driving.

  These loads have a predetermined role in the operation of the device, and when a malfunction such as a failure occurs, the malfunction of the load becomes manifest as various malfunctions of the image forming apparatus. Will do.

  These malfunctions often do not immediately lead to a unique cause, and it is necessary to investigate the cause from a plurality of factors. For example, an operation failure of the paper conveyance unit of the image forming apparatus will be described (see FIG. 2). The paper cassette (21a) stores paper. The pickup roller (22a) is a pickup roller for transporting the paper 206 from the paper cassette (21a). The pickup roller (22a) is driven by a solenoid that vertically drives the pickup roller (22a), and is lowered to contact the paper (206) at the start of paper feeding. When the paper (206) is fed, the pickup roller (22a) is raised to the paper. Separate from (206). The roller pair (23) is a roller for separating and feeding the sheets (206) one by one to the sheet conveyance path (24).

  The paper sensor (112) detects that the paper has reached the paper transport path (24) in a predetermined time after the paper transport is started and that the paper has passed within the predetermined time after the paper is detected. . When the paper sensor (112) cannot detect the paper within a predetermined time after the paper conveyance is started, or when the paper does not finish passing the paper sensor (112) within the predetermined time after detecting the paper, the paper jam has occurred. become.

  The cause of the paper jam is a defect such as a sensor for detecting the paper, a mechanical part for driving the sensor ON / OFF, a roller for conveying the paper (22a), a motor for driving the roller pair (23), etc. There is. In addition, there are a wide variety of problems such as poor connection of the solenoid driving the pickup roller (22a) up and down, mechanical mechanisms related thereto, sensors, solenoids, connectors for driving the motor, signal disconnection, and defective control board. For this reason, it has often taken time to quickly investigate and repair the cause of such problems.

  Under such circumstances, particularly in recent image forming apparatuses, there is an increase in signal / control load due to complicated control, and a large number of signal connectors are drawn from a substrate for controlling them. The large number of connectors to be connected is one of the causes for forgetting to connect the connectors at the time of manufacturing or device maintenance, or causing a connection failure. From the various phenomena that occur, it is necessary to identify the various causes as described above until it is determined that the cause is a connection failure of the connector.

Moreover, regarding the connection detection of a connector, the method of patent document 1 is disclosed. In this method, the first end of the connector on the control board side is pulled up, the other end is connected to GND, both ends of the connector are connected by the wiring of the connector or the connection destination board, etc. This is a method for detecting connection of a connector by monitoring the voltage at one end.
JP 05-289790 A

  However, in the conventional connector connection detection method, detection is required for each connector. For this reason, it is difficult to quickly identify the connector disconnection point. That is, when there is a connection failure of a connector, it is difficult to quickly take a clear response such as which connector is disconnected.

Accordingly, an object of the present invention that the device before gone abnormal operation, provides a connection detection equipment that can identify where rapid connector disconnection from a plurality of connectors.

The connector connection detecting device according to the present invention includes a first pin and a third pin corresponding to the first pin and the second pin, respectively, corresponding to the first to N mounted connectors having the first pin and the second pin. And a first to Nth (N is an integer greater than or equal to 3) mounting side connectors each having a fourth pin. of the mounted connector of the N, with connecting the first pin of the first-mating attachment connector to a power supply via a first resistor, the second of said first mating attachment connector Are connected to the ground via a first capacitor, and the first pins of the second to (N-1) -th mounted connectors are connected to the first to (N-2) -th mounted connectors, respectively. Connected to the second pin, and the second to (N-1) th mounted Said second pin of the terminating connector each via a second capacitor to the (N-1) th capacitors to ground, the second pin of the mounting side connector of the N via the capacitor of the N together to ground Te, connecting said first said first pin of the mounting side connector N in the second pin of the first N-1 of the attached connector, the mounting of the first to N is constructed by conduction with each of the third pin of the side connector and said fourth pin, the rise time measuring means for measuring a voltage rising time of the first pin of the first mating attachment connector And a connection status detecting means for detecting the connection status of each of the first to Nth attached connectors according to the voltage rise time measured by the time measuring means .

The connector connection detection device of the present invention measures the voltage rise time of the first pin of the first attached connector, and detects the connection status of a plurality of connectors according to the measured voltage rise time. Thereby, the unconnected location of the connector can be determined in advance based on the charging time of the capacitor. Therefore, the problem location can be quickly identified before the apparatus performs an abnormal operation.

According to the connector connection detection device of the second aspect , the configuration can be simplified. According to the connector connecting apparatus according to claim 3, used for and others can easily know the location omission connector. According to the connector connecting device of the fourth aspect , it is possible to ensure the operation within the normal range.

The connector embodiments of the connection detection equipment of the present invention will be described with reference to the drawings. Connection detection equipment of the present embodiment is applied to the connection detection of a plurality of connectors attached to an electrophotographic color copying machine of the control board is an image forming apparatus.

[First Embodiment]
FIG. 1 is a cross-sectional view schematically showing the overall configuration of the electrophotographic color copying machine according to the first embodiment. The electrophotographic color copying machine of this embodiment is a color image output apparatus in which a plurality of image forming units are arranged in parallel and an intermediate transfer method is adopted.

  This electrophotographic color copying machine has an image reading unit 1R and an image output unit 1P. The image reading unit 1R optically reads a document image, converts it into an electrical signal, and transmits it to the image output unit 1P. The image output unit 1P includes a plurality (four in this embodiment) of image forming units 10 (10a, 10b, 10c, and 10d) arranged in parallel, a paper feeding unit 20, an intermediate transfer unit 30, a fixing unit 40, and a cleaning unit 50. And a control unit 80.

  Each unit will be described in detail. Each image forming unit 10 (10a, 10b, 10c, 10d) has the same configuration. In each image forming unit 10 (10a, 10b, 10c, 10d), a drum-shaped electrophotographic photosensitive member as a first image carrier, that is, a photosensitive drum 11 (11a, 11b, 11c, 11d) is freely rotatable. And is rotationally driven in the direction of the arrow in the figure.

  The primary charger 12 (12a, 12b, 12c, 12d), the optical system 13 (13a, 13b, 13c, 13d), and the folding mirror 16 (16a) are opposed to the outer peripheral surfaces of the photosensitive drums 11a to 11d in the rotation direction. 16b, 16c, 16d). Further, a developing device 14 (14a, 14b, 14c, 14d) and a cleaning device 15 (15a, 15b, 15c, 15d) are arranged.

  The primary chargers 12a to 12d give a uniform charge amount of charge to the surfaces of the photosensitive drums 11a to 11d. The optical systems 13a to 13d expose light beams such as laser beams, which are modulated according to the recording image signal from the recording image signal output unit 1R, onto the photosensitive drums 11a to 11d via the folding mirrors 16a to 16d. . Thereby, electrostatic latent images are formed on the photosensitive drums 11a to 11d.

  Each of the developing devices 14a to 14d stores developer of four colors such as yellow, cyan, magenta, and black (hereinafter referred to as “toner”), and visualizes the electrostatic latent image. The visualized visible image is transferred to a belt-like intermediate transfer member as the second image carrier constituting the intermediate transfer unit 30, that is, the intermediate transfer belt 31 in the image transfer regions Ta, Tb, Tc, and Td. Is done.

  On the downstream side of the image transfer regions Ta, Tb, Tc, and Td, the cleaning devices 15a, 15b, 15c, and 15d scrape off toner remaining on the photosensitive drums 11a to 11d without being transferred to the intermediate transfer member, Clean the drum surface. By the above process, image formation with each toner is sequentially performed.

  The paper feeding unit 20 includes cassettes 21a and 21b and a manual feed tray 27 for storing the transfer material P, and pickup rollers 22a, 22b and 26 for feeding the transfer material P one by one from the cassette 21a, 21b or the manual feed tray 27. Have The paper feed unit 20 includes a pair of paper feed rollers 23, a paper feed guide 24, and registration rollers 25a and 25b for further transporting the transfer material P fed from the pickup rollers 22a, 22b, and 26. The registration rollers 25a and 25b are used to send the transfer material P to the secondary transfer region Te in accordance with the image formation timing of each image forming unit.

  In the present embodiment, a cassette 21a that is a paper feeding unit will be described as an example. FIG. 2 is a diagram showing a schematic configuration of the cassette 21a. In the figure, the paper cassette 21a stores paper. The pickup roller 22a is a pickup roller for transporting the paper 206, which is the transfer material P, from the paper cassette 21a. The pickup roller 22a is driven by a solenoid (not shown) that drives the pickup roller 22a up and down, and descends at the start of paper feeding and comes into contact with the paper 206. Separate from 206. The roller pair 23 is a roller for separating and feeding the paper 206 one by one to the paper transport path 24.

  Further, the paper sensor 112 detects that the paper has reached the paper transport path 24 in a predetermined time after the paper transport is started, and detects that the paper passes within a predetermined time after the paper is detected. If the paper sensor 112 cannot detect the paper within a predetermined time after the paper conveyance starts, or if the paper does not finish passing the paper sensor 112 within the predetermined time after detecting the paper, the paper jam has occurred.

  FIG. 3 is a diagram showing a part of the configuration of the control board 114 for controlling the image forming apparatus. The control board 114 is mounted on the control unit 80. In this embodiment, connectors 105, 106, and 107 are attached (mounted) as first, second, and third connectors as first to Nth mounted connectors on the control board 114. . In addition, harness side connectors 106, 108, and 110 are prepared as first to Nth mounting side connectors that fit into the connectors 105, 107, and 109, respectively.

  The pin 105a at the left end of the connector 105 is connected to a power supply 3.3V via a resistor R1 (first resistor), and is connected to a voltage detection circuit (see FIG. 4) to which the voltage detection signal 102 is input. The operation of the voltage detection circuit will be described later.

  The right end pin 105b of the connector 105 is connected to the left end pin 107a of the connector 107, and is also connected to GND (ground) via a resistor R2 (second resistor). The right end pin 107b of the connector 107 is connected to the left end pin 109a of the connector 109, and is connected to GND via the resistor R3. The right end pin 109b of the connector 109 is connected to GND via a resistor R4. These connectors are connected to a main load that controls the cassette 21a.

  The connector 105 is fitted to the harness side connector 106 and connected to a solenoid (SL) 111 that drives the pickup roller 22a up and down. The connector 107 is fitted to the harness side connector 108 and connected to a paper sensor (SNS) 112 that detects the paper on the paper transport path 24. The connector 109 is fitted to the harness side connector 110 and connected to a motor (MT) 113 that rotationally drives the pickup roller 22a and the roller pair 23.

  In each harness-side connector 106, 108, 110, the right end pin (third pin) and the left end pin (fourth pin) are connected by a harness and are electrically connected. Thereby, when each connector is fitted to the connector on the control board, the left and right end pins of the connectors 105, 107, 109 on the control board are respectively connected.

  Here, the connection state between the voltage detection signal 102 and the connector will be described. In the present embodiment, in order to simplify the description, R1 = R2 = R3 = R4 = 10 KΩ. In this case, the second to Nth resistors all have the same resistance value. First, when all the connectors are connected, the voltage Vdet appearing in the voltage detection signal 102 is as shown in Equation (1).

Vdet = 3.3 × (combined resistance of R2, R3, R4) / {(combined resistance of R2, R3, R4) + R1} = 0.825V (1)
Further, when the connector 110 is not connected (including a connection failure), it is the same as the resistor R4 is not connected. Therefore, the voltage Vdet appearing in the voltage detection signal 102 is as shown in Equation (2).

Vdet = 3.3 × (the combined resistance of R2 and R3) / {(the combined resistance of R2 and R3) + R1} = 1.1 V (2)
When the connector 108 is not connected, the resistors R3 and R4 are the same as not connected. Therefore, the voltage Vdet appearing in the voltage detection signal 102 is as shown in Equation (3).

Vdet = 3.3 × R2 / (R2 + R1) = 1.65V (3)
Finally, when the connector 106 is not connected, the resistors R2, R3, and R4 are the same as not connected, so the voltage Vdet that appears in the voltage detection signal 102 is as shown in Equation (4).

Vdet (106 not connected) = 3.3 V (4)
In this way, by detecting the detection voltage Vdet of the voltage detection signal 102, it is possible to determine which of the three connectors is disconnected (is not connected).

  FIG. 4 is a block diagram showing the configuration of the control circuit 300. The control circuit 300 is mounted on the control board 114 and includes an A / D converter 302, a CPU 301, a ROM 303, a RAM 304, an I / O interface 305, and a display unit 306. A solenoid (SL) 111, a paper sensor (SNS) 112, and a motor (MT) 113 are connected to the I / O interface 305 through the connectors. The voltage detection circuit described above mainly includes an A / D converter 302 and a CPU 301. When the voltage detection signal 102 is input to the A / D converter 302 and converted into a digital value, this digital value (voltage detection information) is input to the CPU 301 which is the main CPU of the control. A voltage level is detected.

  The CPU 301 controls the operation of the I / O interface 305 and the display unit 306 and the operation of the entire image forming apparatus while using the RAM 304 as a work memory in accordance with a control program stored in the ROM 303.

  The CPU 301 determines the fitting state of the connector based on the voltage detection information from the A / D converter 302. In the present embodiment, as described above, when the detection voltage Vdet is 0.825V, “all connected”, when 1.1V, “connector 110 not connected”, when 1.65V, “connector 108”. “Not connected” and 3.3 V are determined as “connector 106 not connected”. The CPU 301 prohibits the operation of the I / O interface 305 or displays a warning on the display unit 306 in accordance with the connector connection status (connection status detection of the first to Nth connectors).

  FIG. 5 is a flowchart showing a connector connection detection operation procedure. As described above, this processing program is stored in the ROM 303 and executed by the CPU 301. First, when the image forming apparatus is turned on and the operation of the control board 114 is started, the CPU 301 indicates that all the detection voltage levels of the voltage detection signal 102 which is a connector connection detection signal are connected. It is discriminate | determined whether it is (step S1).

  If the detected voltage level is 0.825 V, the CPU 301 determines that all are connected, ends the processing as it is, performs a normal initialization sequence, and operates the image forming apparatus. On the other hand, if the detected voltage level is not 0.825V in step S1, the CPU 301 determines whether the detected voltage level matches any of 1.1V, 1.65V, and 3.3V (step S2). ).

  If none of the voltage levels match, the CPU 301 determines that the control board 114 has failed, causes the display unit 306 to display a warning display (warning code) indicating that the control board 114 has failed (step S3). The operation is prohibited (step S5). Thereby, it is possible to easily know where the connector is disconnected. Also, abnormal operation can be avoided. Thereafter, the CPU 301 ends this process.

  On the other hand, if the detected voltage level matches any voltage level in step S2, the CPU 301 determines that the connector 110 is 1.1V, the connector 108 is 1.65V, or the connector 106 is 3.3V is not connected. to decide. The CPU 301 displays a warning display for designating an unconnected connector on the display unit 306 (step S4). In step S5, the CPU 301 prohibits the operation of the image forming apparatus. In this case, the CPU 301 identifies the location of the unconnected connector. Depending on the location of the identified unconnected connector, the operation of the image forming apparatus partially (for example, only the load connected to the unconnected connector). May be prohibited (partially prohibited). Thereby, the operation within the normal range can be ensured.

  According to the connector connection detection device of the first embodiment, the unconnected portion of the connector of the control board of the image forming apparatus can be determined in advance based on the voltage value divided by the resistance, and the image forming apparatus is abnormal. The problem location can be quickly identified before the operation is performed. Therefore, it is possible to improve the analysis efficiency of the malfunction of the image forming apparatus. Further, by using the pins on both the left and right sides of the connector, it is possible to detect connector disconnection at an early stage.

  In the first embodiment, the case where the number of connectors is three has been described. However, the number of connectors may be four or more, and similar effects can be obtained.

  The resistors R1 to R4 all have the same resistance value, but there is no problem as long as there is a difference between the resistance values as long as the voltage level of the voltage detection signal 102 can be distinguished.

[Second Embodiment]
In the first embodiment, the voltage value divided by the resistor is used as the connector connection detection method. However, in the second embodiment, the resistors R2 to R4 are replaced with capacitors C1 to C3, and the charging time constant is changed. A case where connector connection detection is performed by detecting a change is shown.

  FIG. 6 is a diagram illustrating a part of the configuration of the control board 414 that controls the image forming apparatus according to the second embodiment. The configuration of the image forming apparatus is the same as that of the first embodiment. Further, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The pin 105a at the left end of the connector 105 is connected to the power supply 3.3V through the resistor R1 and the transistor 403, and is connected to the charging time counting circuit 602 (see FIG. 8) to which the charging time detection signal 402 is input. The operation of this charging time counting circuit will be described later. The power supply connected to the resistor R1 is turned on / off by the transistor 403 in accordance with the charge start control signal 504.

  The right end pin 105b of the connector 105 is connected to the left end pin 107a of the connector 107, and is connected to GND via a capacitor C1 (first capacitor). The right end pin 107b of the connector 107 is connected to the left end pin 109a of the connector 109, and is connected to GND via a capacitor C2 (second capacitor). The right end pin 109b of the connector 109 is connected to GND through the capacitor C3. Thus, the first to Nth capacitors correspond to the capacitors C1, C2, and C3. The second pin (right end pin) of the second to (N-1) th connectors is connected to GND via the second capacitor to the (N-1) th capacitor, respectively.

  Further, these connectors are connected to a main load that controls the cassette 21a. The connector 105 is fitted to the harness side connector 106 and connected to a solenoid (SL) 111 that drives the pickup roller 22a up and down. The connector 107 is fitted to the harness side connector 108 and connected to a paper sensor (SNS) 112 that detects the paper on the paper transport path 24. The connector 109 is fitted to the harness side connector 110 and connected to a motor (MT) 113 that rotationally drives the pickup roller 22a and the roller pair 23.

  In each harness-side connector 106, 108, 110, the rightmost pin and the leftmost pin are connected by a harness. Thereby, when each connector is fitted to the connector on the control board, the left and right end pins of the connectors 105, 107, 109 on the control board are respectively connected.

  Here, the charging time detection signal 402 and the connection status of the connector will be described. FIG. 7 is a graph showing how long it takes to reach a predetermined threshold level after charging the capacitor. The horizontal axis of the graph indicates the charging time, and the vertical axis indicates the charging voltage. Here, all the capacitors C1, C2, and C3 have the same capacitance value.

  First, when all the connectors are connected, all the capacitors C1, C2, and C3 are charged, so that the charging time is the longest as shown by the line C = C1 + C2 + C3. Therefore, the time required to reach the threshold voltage Vth is t3.

  In addition, when the connector 110 is not connected, the two capacitors C1 and C2 are charged, so the charging time is as shown by the line C = C1 + C2. Therefore, the time required to reach the threshold voltage Vth is t2.

  Further, when the connector 108 is not connected, only the capacitor C1 is charged, so the charging time is as shown by the line C = C1. Therefore, the time required to reach the threshold voltage Vth is t1.

  Finally, when the connector 106 is not connected, the capacitor is not charged, so the charging voltage immediately rises and the charging time is time zero.

  In this way, by detecting the time when the charging time detection signal 402 reaches the predetermined threshold, it is possible to determine which of the three connectors is disconnected.

  FIG. 8 is a block diagram showing the configuration of the control circuit 300. The same components as those in the first embodiment are denoted by the same reference numerals. The control circuit 300 is mounted on the control board 114 and includes a charging time counting circuit 602, a CPU 301, a ROM 303, a RAM 304, an I / O interface 305, and a display unit 306.

  In the control circuit 300, when the charging time detection signal 402 is input to the charging time counting circuit 602, the charging time counting circuit 602 counts the rising time until the charging voltage reaches the threshold voltage Vth (rising time measurement). . The counted charging time is input to the CPU 301 which is the main CPU for control.

  The CPU 301 controls the operation of the I / O interface 305 and the display unit 306 and the operation of the entire image forming apparatus while using the RAM 304 as a work memory in accordance with a control program stored in the ROM 303.

  The CPU 301 determines the fitting state of the connector based on the charging time information from the charging time counting circuit 602. In this embodiment, as described above, when the charging time t is t3, “all connected”, when t2, “connector 110 not connected”, when t1, “connector 108 not connected”, charging time When t is time 0, it is determined that “connector 106 is not connected”. The CPU 301 prohibits the operation of the I / O interface 305 or displays a warning on the display unit 306 according to the connector connection status.

  The timing for starting the detection of the charging time is a timing at which the charging start signal 504 output from the I / O interface 305 by the CPU 301 drives the transistor 403. When the charging start signal 504 is input, the charging time counting circuit 602 starts measuring the charging time. When the voltage level of the charging signal detection signal 402 reaches the threshold voltage Vth, the charging time counting circuit 602 ends the charging time measurement.

  FIG. 9 is a flowchart showing a connector connection detection operation procedure. As described above, this processing program is stored in the ROM 303 and executed by the CPU 301. First, when the image forming apparatus is turned on and the operation of the control board 414 is started, the CPU 301 turns on the charging start signal (step S11).

  The CPU 301 determines whether or not the charging time t detected by the charging time detection signal 402 is a time t3 indicating that all are connected (step S12). When it is time t3, since all the connectors are connected, the CPU 301 ends this processing as it is, performs a normal image forming apparatus initialization sequence, and operates the image forming apparatus.

  On the other hand, if it is not time t in step S12, the CPU 301 determines whether or not it matches any of time t2, t1, and time 0 (step S13). If none of them match, the CPU 301 determines that the control board 414 has failed, displays a warning display indicating the failure of the control board 414 on the display unit 306 (step S14), and prohibits the operation of the image forming apparatus (step S14). S16). Thereafter, the CPU 301 ends this process.

  On the other hand, if either of them is met in step S13, the CPU 301 determines that the connector 110 is not connected at time t2, the connector 108 is at time t1, and the connector 106 is not connected at time 0. Then, the CPU 301 displays a warning display for designating an unconnected connector on the display unit 306 (step S15), and prohibits the operation of the image forming apparatus in step S16. In this case, the CPU 301 identifies the location of the unconnected connector. Depending on the location of the identified unconnected connector, the operation of the image forming apparatus partially (for example, only the load connected to the unconnected connector). May be prohibited.

  As described above, according to the connector connection detecting device of the second embodiment, the unconnected portion of the connector of the control board of the image forming apparatus can be determined in advance based on the charging time of the capacitor, and the image forming apparatus is abnormal. The problem location can be quickly identified before the operation is performed. Therefore, it is possible to improve the analysis efficiency of the malfunction of the image forming apparatus.

  In the second embodiment, the case where the number of connectors is three has been described. However, similarly to the first embodiment, the number of connectors may be four or more, and the same effect can be obtained. is there.

  The capacitors C1 to C3 all have the same capacitance value. However, even if there is a difference in capacitance value, there is no problem as long as the charging time detection signal 402 that can be electrically detected can be distinguished.

[Third Embodiment]
In the first embodiment, when determining whether or not a connector connected to the control board is not connected based on the voltage value divided by the resistor, all the resistance values are the same. It is easy to change the resistance value according to the performance of the detection circuit. In the third embodiment, a case in which unconnected connectors are detected based on voltage values divided by resistors having different resistance values is shown.

  FIG. 10 is a diagram illustrating a part of the configuration of a control board 1027 for controlling the image forming apparatus according to the third embodiment. The configuration of the image forming apparatus is the same as that of the first embodiment. Further, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Here, a case where six connectors are connected to the control board 1027 is shown. In other words, in the present embodiment, the control board 1027 has connectors 1009 and 1011 as the first, second, third, fourth, fifth, and sixth connectors as the first to Nth mounted connectors. 1013, 1015, 1017, 1019 are attached. The second to (N-1) th connectors correspond to the connectors 1011, 1013, 1015, and 1017. In addition, harness side connectors 1010, 1012, 1014, 1016, 1018, and 1020 are prepared as first to Nth mounting side connectors that fit into the connectors 1010, 1011, 1013, 1015, 1017, and 1019, respectively.

  The pin 1009a at the left end of the connector 1009 is connected to a power supply 3.3V through a resistor R1, and is connected to a voltage detection circuit (see FIG. 12) to which a voltage detection signal 1002 is input. The operation of this voltage detection circuit is the same as that of the first embodiment.

  The right end pin 1009b of the connector 1009 is connected to the left end pin 1011a of the connector 1011 and is connected to GND through the resistor R2. The right end pin 1011b of the connector 1011 is connected to the left end pin 1013a of the connector 1013, and is connected to GND via the resistor R3. The right end pin 1013b of the connector 1013 is connected to the left end pin 1015a of the connector 1015, and is connected to GND via the resistor R4.

  Further, the right end pin 1015b of the connector 1015 is connected to the left end pin 1017a of the connector 1017, and is connected to the GND via the resistor R5. The right end pin 1017b of the connector 1017 is connected to the left end pin 1019a of the connector 1019, and is connected to GND through the resistor R6. The right end pin 1019b of the connector 1019 is directly connected to GND. As described above, the second pins (right end pins) of the second to (N-1) th connectors are connected to the GND via the third resistor to the Nth resistor, respectively.

  These connectors are connected to main loads for controlling the upper cassette 21a and the lower cassette 21b. In the first embodiment, only the upper cassette 21a is shown, but in the third embodiment, the two cassettes, ie, the upper cassette 21a and the lower cassette 21b are shown.

  FIG. 11 is a diagram showing a schematic configuration of the cassette 21b. In the figure, the paper cassette 21b stores paper. The pickup roller 22b is a pickup roller for transporting the paper 206, which is the transfer material P, from the paper cassette 21b. The pickup roller 22b is driven by a solenoid that drives the pickup roller 22b up and down, and comes down to contact the paper 206 when paper feeding starts. When the paper 206 is fed, the pickup roller 22b goes up and separates from the paper 206. The roller pair 23 is a roller for separating and feeding the paper 206 one by one to the paper transport path 24.

  Further, the paper sensor 1212 detects that the paper has reached the paper transport path 24 in a predetermined time after the paper transport is started, and detects that the paper passes within the predetermined time after the paper is detected. If the paper sensor 1212 cannot detect the paper in a predetermined time after the paper conveyance starts, or if the paper does not finish passing the paper sensor 1212 in the predetermined time after the paper is detected, the paper jam has occurred.

  The connector 1009 is fitted to the harness side connector 1011 and connected to the solenoid 111 that drives the pickup roller 22a (see FIG. 2) up and down. The connector 1011 is fitted to the harness side connector 1012 and connected to the paper sensor 112 that detects the paper on the conveyance path 24. The connector 1013 is fitted to the harness side connector 1014 and connected to the motor 113 that rotationally drives the pickup roller 22a and the roller pair 23.

  The connector 1015 is fitted to the harness side connector 1016 and connected to a solenoid 1211 that drives the pickup roller 22b (see FIG. 11) up and down. The connector 1017 is fitted to the harness side connector 1018 and is connected to a paper sensor 1212 that detects the paper on the conveyance path 24. The connector 1019 is fitted to the harness side connector 1020 and connected to the motor 1213 that drives the pickup roller 22b and the roller pair 23.

  The right end pin and the left end pin of each harness side connector 1010, 1012, 1014, 1016, 1018, 1020 are connected by a harness. Thereby, when each harness side connector is fitted with the corresponding connector on the control board 1027, the left and right end pins of the connectors 1009, 1011, 1013, 1015, 1017, and 1019 on the control board 1027 are respectively connected. It will be.

  FIG. 12 is a block diagram showing the configuration of the control circuit 300. Since the configuration of the control circuit 300 is the same as that of the first embodiment, description of the configuration and its operation is omitted. The I / O interface 305 includes a solenoid (SL) 111 for the upper sheet cassette 21a, a paper sensor (SNS) 112 and a motor (MT) 113, a solenoid 1211 for the lower sheet cassette 21b, and a paper sensor. 1212 and a motor 1213 are connected. Note that the voltage detection circuit to which the voltage detection signal 1002 described above is input mainly includes an A / D converter 302 and a CPU 301.

  Here, as in the first embodiment, the case where the resistors R1 to R6 all have the same resistance value = 10 KΩ is shown. FIG. 13 is a graph showing the relationship between the connector connection status and the voltage detection signal 1002 when the resistors R1 to R6 all have the same resistance value = 10 KΩ.

  In the figure, the horizontal axis indicates the connector disconnection location, and the vertical axis indicates the value of the voltage detection signal 1002. The detection voltage Vdet of the voltage detection signal 1002 corresponding to the connector disconnection location is as follows.

  Connector disconnection location 1: When all the connectors are all connected, the right pin 1019b of the connector 1019 is connected to GND, and thus the detection voltage Vdet is expressed by Equation (5).

Vdet = 0V (5)
Connector disconnection location 2: When the connector 1020 is disconnected, the detection voltage Vdet is expressed by Equation (6).

Vdet = 3.3 × (the combined resistance of R2 to R6) / {(the combined resistance of R2 to R6) + R1}
= 0.55V (6)
Connector disconnection point 3: When the connector 1018 is disconnected, the detection voltage Vdet is expressed by Equation (7).

Vdet = 3.3 × (the combined resistance of R2 to R5) / {(the combined resistance of R2 to R5) + R1}
= 0.66V (7)
Connector disconnection point 4: When the connector 1016 is disconnected, the detection voltage Vdet is expressed by Equation (8).

Vdet = 3.3 × (R2 to R4 combined resistance) / {(R2 to R4 combined resistance) + R1}
= 0.825V (8)
Connector disconnection portion 5: When the connector 1014 is disconnected, the detection voltage Vdet is expressed by Equation (9).

Vdet = 3.3 × (combined resistance of R2 to R3) / {(combined resistance of R2 to R3) + R1}
= 1.1V (9)
Connector disconnection point 6: When the connector 1012 is disconnected, the detection voltage Vdet is expressed by Equation (10).

Vdet = 3.3 × R2 / (R2 + R1)
= 1.65V (10)
Connector disconnection point 7: When the connector 1010 is disconnected, the detection voltage Vdet is expressed by Equation (11).

Vdet = 3.3V (11)
As can be seen from the graph of FIG. 13, when the resistance values are the same, the difference in the voltage level of the voltage detection signal 1002 becomes smaller as the number of connectors connected increases. The voltage level difference is 0.11V. As a result, it is not easy to determine where the connector is disconnected, and conversion accuracy is required for the A / D converter 302 in the subsequent stage.

  When the difference in voltage level of the voltage detection signal 1002 is reduced by increasing the number of connectors in this way, the values of the resistors R2 to R6 are changed from the resistor R1 so that R2> R3> R4> R5> R6. What is necessary is just to set so that resistance value may become so small that resistance is far. In this case, the third to Nth resistors have smaller resistance values than the second to (N-1) th resistors, respectively.

  FIG. 14 is a graph showing the relationship between the connector connection state and the voltage detection signal 1002 when the resistance value is actually changed. Here, R2 = 51 KΩ, R3 = 33 KΩ, R4 = 20 KΩ, R5 = 9.1 KΩ, and R6 = 3.3 KΩ. Further, in the figure, the horizontal axis indicates the connector disconnection portion, and the vertical axis indicates the value of the voltage detection signal 1002. The detection voltage Vdet corresponding to the connector disconnection portion is as follows.

  Connector missing part 1: When all the connectors are all connected, the right pin 1019b of the connector 1019 is connected to the GND, so that the detection voltage Vdet is expressed by Expression (12).

Vdet = 0V (12)
Connector disconnection location 2: When the connector 1020 is disconnected, the detection voltage Vdet is expressed by Equation (13).

Vdet = 3.3 × (the combined resistance of R2 to R6) / {(the combined resistance of R2 to R6) + R1}
= 0.54V (13)
Connector disconnection point 3: When the connector 1018 is disconnected, the detection voltage Vdet is expressed by Equation (14).

Vdet = 3.3 × (the combined resistance of R2 to R5) / {(the combined resistance of R2 to R5) + R1}
= 1.07V (14)
Connector disconnection point 4: When the connector 1016 is disconnected, the detection voltage Vdet is expressed by Equation (15).

Vdet = 3.3 × (R2 to R4 combined resistance) / {(R2 to R4 combined resistance) + R1}
= 1.65V (15)
Connector disconnection portion 5: When the connector 1014 is disconnected, the detection voltage Vdet is expressed by Equation (16).

Vdet = 3.3 × (combined resistance of R2 to R3) / {(combined resistance of R2 to R3) + R1}
= 2.2V (16)
Connector disconnection point 6: When the connector 1012 is disconnected, the detection voltage Vdet is expressed by Equation (17).

Vdet = 3.3 × R2 / (R2 + R1)
= 2.8V (17)
Connector disconnection point 7: When the connector 1010 is disconnected, the detection voltage Vdet is expressed by Equation (18).

Vdet = 3.3V (18)
As is apparent from FIG. 14, even when the number of connectors to be connected increases, the voltage level difference of the voltage detection signal 1002 can be made equal. In this embodiment, it is set so as to change by approximately 0.5V.

  In the control device of the third embodiment, the values of the resistors R2 to R6 are set so that the resistance value becomes smaller as the resistor is farther from the resistor R1 so that R2> R3> R4> R5> R6. Thereby, the voltage level difference of the voltage detection signal 1002 can be made equal. Therefore, even in a large-scale control circuit with a large number of connectors, it is possible to easily identify a connector disconnection point. Note that in all of the resistors R2 to R6, the value of the resistance in the subsequent stage (for example, the resistance R3 compared to the resistance R2) is not made smaller than the resistance in the previous stage, that is, the values of some of the front and rear resistances are equal. However, almost the same effect can be obtained. Further, according to the first and second embodiments, the operation of the image forming apparatus (for example, only the load connected to the unconnected connector) may be partially prohibited depending on the location of the unconnected connector. It is the same as the form.

  The present invention is not limited to the configuration of the above-described embodiment, and any configuration can be used as long as the functions shown in the claims or the functions of the configuration of the present embodiment can be achieved. Is also applicable.

For example, in the second embodiment, the capacitors C1, C2, and C3 have the same capacitance value, but may have capacitance values that satisfy C1 ≦ C2 ≦ C3. In this case, each of the second to Nth capacitors has the same capacitance value as the first to N-1th capacitors or a larger capacitance value. Thereby, the difference in the rise time can be adjusted, and the connector disconnection point can be specified more easily.

  In the above-described embodiment, the case where the present invention is applied to a control board in a color copying machine as an image forming apparatus has been described. However, the present invention can be applied to a board in any apparatus. In particular, in the above-described embodiment, the control board that controls the paper cassette of the image forming apparatus is shown. However, a control board that controls the fixing device may be used. Further, the present invention is not limited to the connector attached to the substrate, but can be applied to the connection detection between the connectors in the state of being pulled out from the substrate and each part in the apparatus.

  The connector connection detection device of the present invention is applicable to, for example, a control board that controls an image forming apparatus.

1 is a cross-sectional view schematically showing an overall configuration of an electrophotographic color copying machine according to a first embodiment. It is a figure which shows schematic structure of the cassette 21a. It is a figure which shows a part of structure of the control board 114 which controls an image forming apparatus. 2 is a block diagram showing a configuration of a control circuit 300. FIG. It is a flowchart which shows a connector connection detection operation procedure. FIG. 10 is a diagram illustrating a part of the configuration of a control board 414 that controls an image forming apparatus according to a second embodiment. It is a graph which shows how long it reaches | attains to a predetermined threshold level after charging starts a capacitor | condenser. 2 is a block diagram showing a configuration of a control circuit 300. FIG. It is a flowchart which shows a connector connection detection operation procedure. FIG. 10 is a diagram illustrating a part of the configuration of a control board 1027 that controls an image forming apparatus according to a third embodiment. It is a figure which shows schematic structure of the cassette 21b. 2 is a block diagram showing a configuration of a control circuit 300. FIG. It is a graph which shows the relationship between the connection condition of a connector and the voltage detection signal 1002 in case all resistance R1-R6 is the same resistance value = 10Kohm. It is a graph which shows the relationship between the connection state of the connector when a resistance value is actually changed, and the voltage detection signal 1002.

Explanation of symbols

105, 106, 107, 108, 109, 110 Connector 114, 414 Control board 300 Control circuit 301 CPU
302 A / D converter 306 Display unit 602 Count circuit R1, R2, R3, R4 Resistor C1, C2, C3 Capacitor

Claims (4)

First to Nth (N is an integer greater than or equal to 3) mounted connectors having a first pin and a second pin, and third pins corresponding respectively to the first pin and the second pin When the first to Nth mounting side connectors having the fourth pin and the fourth pin are respectively mounted, a connector connection detecting device for detecting the connection of the connector,
Among the first to Nth mounted connectors, the first pin of the first mounted connector is connected to a power source via a first resistor, and the first mounted connector Connecting the second pin of the first to the ground via a first capacitor;
The first pins of the second to (N-1) mounted connectors are connected to the second pins of the first to (N-2) mounted connectors, respectively. -1 connected to the ground through the second capacitor to the (N-1) th capacitor, respectively, of the second pin of the attached side connector,
The second pin of the Nth mounted connector is connected to the ground via an Nth capacitor, and the first pin of the Nth mounted connector is connected to the N-1th mounted device. Connected to the second pin of the side connector;
The third pin and the fourth pin of each of the first to Nth mounting side connectors are electrically connected to each other.
Rise time measuring means for measuring a voltage rise time of the first pin of the first mounted connector;
Connector connection detection, comprising: connection status detection means for detecting the connection status of each of the first to Nth attached connectors according to the voltage rise time measured by the time measurement means. apparatus. The first to connector connection detection apparatus according to claim 1, characterized in that it has the same capacitance value all capacitors of the N. The first to Nth mounted connectors are mounted on a control board, and a device for mounting the control board has a display device,
A warning display means for displaying a warning when any of the first to Nth mounted connectors is detected as being unconnected by the connection status detection means. Item 3. The connector connection detection device according to item 1 or 2 . The first to Nth mounted connectors are mounted on a control board in the apparatus;
Detected by the connection state detecting means, in accordance with the unconnected state of the mounting side connector of the first to N, to claim 1 or 2, characterized in that prohibiting at least some operations of the device The connector connection detection apparatus of description.

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