JP2008056479A - Paper feeder and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inform a user of abnormal carriage in a paper carrying passage even in a power consumption saving mode. <P>SOLUTION: This paper feeder having a low power consumption mode comprises paper detecting sensors 210-a, 210-b for detecting the existence or not of paper at a predetermined position in the paper carrying passage, light emitting elements 211-a, 211-b for displaying the detecting conditions of the paper detecting sensors 210-a, 210-b, a timer counting part for counting a preset time, a control part 201 for controlling each part of the device and each means, and a change-over circuit 208 for changing over a signal transmitting circuit among the paper detecting sensors 210-a, 210-b, the light emitting elements 211-a, 211-b, and the control part 201. When paper feeding operation is finished or interrupted, the timer counting part start to count a time from finishing or interrupting it. When the timer counting part counts a time over the preset time, the control part 201 transfers a mode into the low power consumption mode and the change-over means changes over the signal transmitting circuit into a predetermined transmitting passage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet feeding device that supplies a sheet-like recording medium (herein simply referred to as a sheet) such as recording paper, paper, transfer paper, and OHP sheet, and a copier, printer, The present invention relates to an image forming apparatus such as a facsimile or a digital multi-function peripheral, and more particularly to a sheet feeding apparatus and an image forming apparatus having a function of a low power consumption mode (energy saving mode).

2. Description of the Related Art Conventionally, an image forming apparatus such as a copier, a printer, a facsimile, or the like has been provided with a display device that uses a light emitting element such as an LED and displays a conveyance status in order to inform a user of the conveyance status of a sheet in a sheet conveyance path. Known from. This display device is configured so that, for example, green lights up during normal operation and red lights up when there is an abnormality such as a paper jam. When the display device is composed of light emitting elements, when detecting that a paper jam has occurred in the paper conveyance path and lighting or flashing the light emitting elements, for example,
1) First, a signal from the sheet detection means arranged in the sheet conveyance path is transmitted to the CPU in the apparatus main body.
2) The CPU processes the signal information and transmits a control signal to the light emitting element.
Control is performed. When controlled in this way, since the CPU controls a plurality of light emitting elements, each light emitting element can be turned on or blinked, and the blinking interval can be freely controlled.

  In this control, the CPU determines the state of paper conveyance in the paper conveyance path, and the CPU transmits a control signal to the light emitting element to turn on or blink the light emitting element as described above. When an abnormality such as clogging occurs, the light emitting element normally continues to be lit or blinking to indicate the occurrence of the abnormality until the abnormality is resolved, and the user is informed that the paper feeding device is in an abnormal state.

On the other hand, a power saving mode (low power consumption mode) in which the power supply to the CPU is stopped when the image forming operation is not performed is widely used for the purpose of protecting the environment and reducing the use cost. However, in the image forming apparatus incorporating the power saving mode, the power supply to the CPU is stopped when the power saving mode is entered in the abnormal state, and thus the display device cannot be controlled. The user cannot be notified of the abnormal state. Thus, for example, Patent Documents 1 and 2 propose that when the image formation is not performed, the power source of the sensor necessary for the image formation is shut off so that the sensor that detects a paper jam or the like is operable.
JP-A-2005-25066 Japanese Patent No. 3627723

  However, in the above prior art, when the user is not in the vicinity of the apparatus such as at night, for example, when the apparatus performs a paper feeding operation by facsimile reception or the like and a paper jam occurs, the mode is shifted to the power saving consumption mode. However, until the user clears the paper jam the next morning, the above-mentioned drawbacks can be solved by turning on and blinking the display device by CPU control, but it is not possible to shift to the power saving consumption mode. , Wastes power.

  The present invention has been made in view of such a state of the prior art, and an object thereof is to make it possible to notify the user of a conveyance abnormality in the sheet conveyance path even in the power saving consumption mode.

  In order to achieve the above object, the first means includes a sheet detecting means for detecting presence / absence of a sheet at a predetermined position in the sheet conveying path in the sheet feeding device having a low power consumption mode, and detection by the sheet detecting means. Display means for displaying the status, timing means for timing a preset time, control means for controlling each part of the apparatus and each means, signals between the paper detection means, the display means and the control means Switching means for switching the transmission circuit, and when the paper feeding operation is completed or interrupted, the time measuring means starts counting from the time when the paper feeding operation ends or is interrupted, and the control means counts the time measured by the time measuring means When a preset time has elapsed, the mode is shifted to the low power consumption mode, and the switching means switches the signal transmission circuit to a predetermined signal path.

  The second means is characterized in that, in the first means, the predetermined signal path is a path for directly transmitting the presence / absence information of the sheet transmitted from the sheet detection unit to the control unit to the display unit. .

  The third means is characterized in that in the first or second means, the operation means further includes an operation unit capable of arbitrarily setting a time measured by the time measuring means after the paper feeding operation is finished or interrupted. .

  According to a fourth means, in any one of the first to third means, a switching signal input to the switching means is supplied from a driving power source of the control means.

  A fifth means is characterized in that, in the fourth means, the switching signal is automatically generated from a power supply state at the time of shifting / non-shifting to a power saving mode.

  A sixth means is characterized in that, in the first means, a plurality of the paper detection means are arranged at intervals in the paper conveyance direction of the paper conveyance path.

  A seventh means is any one of the first to sixth means, wherein the paper detection means comprises a photo reflector.

  According to an eighth means, in any one of the first to sixth means, the display means is an LED.

  A ninth means is characterized in that the image forming apparatus includes a paper feeding device according to any one of the first to eighth means. In the embodiments described later, the paper detection means is the paper detection section 210, the first and second paper detection sensors 210-a and 210-b, and the display means is the display section 211, the first and second light emitting elements 211. -A, 211-b, the control means is the control section 201, the switching means is the switching circuit 208, the time measurement means is the timer count section 215, the operation section is the reference number 212, the photo reflector is the reference number 410-a, The LED corresponds to reference numerals 411-a and 411-b, respectively.

  According to the present invention, since the paper detection means and the display means function even when the power of the control means is stopped after shifting to the low power consumption mode, the user can carry the paper in the paper conveyance path even in the low power consumption mode. You can know the abnormality.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus including a sheet feeding device according to an embodiment of the present invention. In this embodiment, an electrophotographic copying machine is taken as an example of the image forming apparatus. Since the function of the copying machine is general, only the outline of the configuration will be described.

  The copying machine includes a reading unit 120, a writing unit 130, an image forming unit 160, a paper feeding unit 170, a fixing unit 180, and a paper discharging unit 190. The reading unit 120 includes a light source 121, a condenser lens 122, a reflection mirror group 123, a reading element 124, and a fan 125. A light source 121 is a light source of illumination light that illuminates the document. The reflected light reflected from the document by illumination is guided to the condensing lens 122 through the mirror group 123, and the collected reflected light is incident on the reading element 124. . The reading element 124 converts incident light into an electric signal and outputs the electric signal as an original read. The fan 125 has a function of releasing heat generated from the light source 121 to the outside.

  The writing unit 130 includes a light emitting source 131, a polygon mirror 132, a lens group 133, and a mirror 134. The light source 132 is a laser light source, and the laser light emitted from the light source 132 is condensed into a linear shape and enters the polygon mirror 132. The inclination of the laser light reflected by the polygon mirror 132 is corrected by a lens group consisting of a barrel toroidal lens and an fθ lens, converted from a uniform angular velocity deflection to a uniform velocity deflection, and incident on the mirror 134 to be exposed to the image forming unit. The surface of the body drum 136 is irradiated.

  The image forming unit 160 includes the photosensitive drum 136, a charging charger 135 disposed along the outer periphery of the photosensitive drum 136, a developing device (developing roller) 137, a transfer charger 140, a separation charger 141, a cleaning unit 143, and a not-shown unit. Equipped with a static elimination charger. Optical writing from the writing unit 130 is performed on the surface of the photosensitive drum 136 charged by the charging charger 135, and an electrostatic latent image is written. The electrostatic latent image is developed with toner by the developing unit 137, transferred to the sheet side by the transfer charger 140, separated from the sheet by the separation charger 141, and then conveyed to the fixing unit 180 side. The toner remaining on the photosensitive drum side without being transferred to the paper side by the transfer charger 140 is cleaned by the cleaning unit 143. Further, the charge remaining on the surface of the photosensitive drum 136 is discharged by the static eliminator and used for the next image formation. Prepare.

  The paper feed unit 170 includes a paper feed cassette 138, a paper feed roller 139, and a registration roller 146. In the present embodiment, two sheet feeding cassettes 138 are provided, and a sheet feeding roller 139 is disposed on the most downstream side of the sheet feeding cassette 138. The registration roller 146 is provided on the downstream side of the paper feed roller 139 and the upstream side of the transfer charger 140, and feeds the paper in time with the leading edge of the toner image developed on the photosensitive drum 136. This paper feeding unit functions as a paper feeding device.

  The fixing unit 180 includes a transport device 147 and a thermal fixing device 142. The thermal fixing device 142 includes a heating roller and a pressure roller. The paper separated from the photosensitive drum 136 by the separation charger 141 is conveyed by the conveyance device 147, and the paper passes through the nip between the heating roller and the pressure roller. In the meantime, the toner is fixed on the paper surface by heat and pressure. The conveying device 147 attracts the sheet onto the conveying belt by the negative pressure generated by the intake air, and guides the sheet to the nip.

  The paper discharge unit 190 includes a paper discharge roller group 144, a tray selector 145, a plurality of paper discharge trays 101, and a paper discharge detection device 102. The paper discharge unit 190 functions as a sorter, and the paper discharge detection device 102 detects the presence or absence of paper on the paper discharge tray 101 and the stacking height of the paper.

  An operation display device 150 is provided at the upper part of the image forming apparatus main body. The operation display device 150 is provided with operation buttons for operation input, a liquid crystal display panel for displaying various operation information and operation information including detection states of a paper feed unit, an image forming unit, and a paper discharge unit, A display unit 211 is provided for displaying the paper conveyance state.

  FIG. 2 is a block diagram showing a control (electrical) configuration of the paper feeding unit 170. The control configuration of the paper feed unit 170 includes a main body control board 217, a power source 214, an operation unit 212, a paper detection unit 210, and a display unit 211, and a main body control board 271 is connected to the paper feed unit 200. The power source 214 is turned on / off by a power switch (SW) 213 and supplies power to a motor (not shown) for driving the paper feed roller 139. The operation unit 212 gives instructions and displays for operating the paper feed unit 200. The main body control board 217 controls the entire image forming apparatus, and the paper detection unit 210 detects the presence or absence of paper in the paper transport path. The display unit 211 displays the sheet conveyance status of the sheet feeding unit to the user, and includes a light emitting element. The main body control board 217 includes a CPU circuit unit 202, an IO circuit unit 206, and a switching circuit 208. The CPU circuit 202 includes a timer count unit 215 that counts a predetermined time. The IO circuit unit 206 inputs / outputs signals to / from a load such as a paper detection unit 210, a display unit 211, other sensors (not shown), and a motor, and the switching circuit 208 receives the paper detection unit 210 and the display unit 211 by a switching signal 209. And switch.

  FIG. 3 is a block diagram showing the main body control board 217 of FIG. 2 in more detail. The main body control board 217 basically includes a control unit 201 and a switching circuit 208. The control unit 201 includes a CPU circuit unit 202 and an IO circuit unit 206. The CPU circuit unit 202 mainly includes a CPU 203 that controls the paper feeding unit and the entire copier, a ROM 204 that stores a control program, and a RAM 205 that provides a work area necessary for control. Although not shown here, the CPU 203 includes the timer count unit 215 shown in FIG. An IO control ASIC 207 is mounted on the IO circuit unit 206, and the IO control ASIC 207 performs IO control. The IO circuit unit 206 is connected to the CPU circuit unit 202 and the switching circuit 208, and a circuit switching signal 209 is applied to the switching circuit 208.

  In the present embodiment, the paper detection unit 210 includes first and second paper detection sensors 210-a and 210-b, and the first and second paper detection sensors 210-a and 210-b are paper. They are arranged in this order from the upstream side in the transport direction. The display unit 211 includes first and second light emitting elements 211-a and 211-b corresponding to the first and second paper detection sensors 210-a and 210-b, respectively. These light emitting elements 211-a and 211-b light up or blink according to the paper detection state of the paper detection sensors 210-a and 210-b.

  A procedure when the CPU 203 processes the signal of the sheet detection unit 210 in this control configuration will be described. First, when a sheet is conveyed and the leading end of the sheet reaches the first sheet detection sensor 210-a, the detection information is transmitted to the CPU 203. The CPU 203 that has received the detection information starts counting time in the timer count unit 215 from the moment of reception. Then, when information indicating that there is a sheet is transmitted from the second sheet detection sensor 210-b within a certain time from the start of counting, it is determined that the sheet is normally conveyed on the sheet conveyance path, and the CPU 203 displays the display unit. The control signal of the light emitting element during normal operation is output to 211. On the other hand, if no paper presence information is transmitted from the paper detection sensor 210-b within a certain time from the start of counting, the paper is jammed somewhere and it is determined that the paper is jammed. Thereby, the CPU 203 outputs a control signal at the time of paper jam to the display unit 211, the signal is transmitted to the display unit 211 through the IO control ASIC 207, and the light emitting elements 211-a and 211b of the display unit 211 are lit and blinked. Alternatively, counting of time is started from the moment when the leading edge of the paper reaches the paper detection unit 210, and even when the paper detection unit 210 continues to transmit information on the presence of paper for a certain period of time, a paper jam occurs near the paper detection unit 210. It is determined that it has occurred, and control signals for the light emitting elements 211-a and 211b at the time of paper jam are output. The term “within a certain period of time” depends on the size of the paper to be transported. As the paper size increases, this time also increases in proportion thereto. The relationship between the paper size and a predetermined time is normally stored in the ROM 204 in the CPU circuit unit 202. When the preset power saving mode transition time has elapsed, the apparatus enters the power saving mode. In the present embodiment, the first sheet detection sensor 210-a is, for example, immediately after the sheet conveyance direction of the paper feed roller 146, and the second sheet detection sensor 210-b is, for example, the sheet conveyance direction of the registration roller 146. It is good to provide them just before Note that the installation positions of the sheet detection sensors 210-a and 210-b are set as appropriate according to the configuration, type, and conveyance path length of the sheet feeding device.

  FIG. 4 is a flowchart showing an operation procedure of the sheet feeding unit in the present embodiment. In the figure, when the operation starts, first, the timer count unit 215 starts counting time (step S1001), and performs a paper feeding operation (step S1002). Therefore, as described above, the CPU 203 processes a predetermined relationship between the information from the sheet detection unit 210, the sheet size stored in the ROM 205, and the conveyance time, and checks whether or not the sheet conveyance has been completed normally (step). S1003). If it is determined that the sheet conveyance has been completed normally, it is checked whether or not there is a next sheet feeding operation (step S1004). When there is a next paper feeding operation, the timer count is once stopped / cleared (step S1005), and the process returns to step S1001 again. The count is started and the next paper feeding operation is started.

  If there is no next paper feeding operation in step S1004, the counting is continued, and it is checked whether the count time is the same as the energy saving set time (step S1006). If the same time is reached, the apparatus enters the power saving mode.

  In step S1003, the CPU 203 processes the relationship between the information from the paper detection unit 210 and the certain time stored in the ROM 205, and if it is not determined that the paper conveyance has been completed normally, a paper jam occurs. It is determined that it has been done (step S1007). Then, it is checked whether the paper jam has been eliminated (step S1008). If the paper jam is not cleared, the process proceeds to step S1006 and continues counting. When the count time becomes the same as the energy saving setting time, the power saving mode is entered.

  At this time, the CPU 203 switches the circuit switching signal 209 and directly connects the paper detection unit 210 and the display unit 211 by the switching circuit 208. Even if the power supply of the CPU 203 is stopped in this state, the light emitting element can be turned on. Here, the case where the paper detection unit 210 is in the paper conveyance path has been described, but the paper detection unit 210 is not limited thereto, and may be installed outside the paper conveyance path, for example. For example, an operation of a component that is turned on only when there is a sheet in the sheet conveyance path may be detected.

  FIG. 5 is a block diagram showing a specific example of the switching circuit 208 of FIG. The switching circuit 208 basically includes first and second selectors 301 and 302, a driver 303, and an inverter 304. In addition to the power supply input terminal and the GND terminal for the selector itself, the first and second selectors 301 and 302 have a signal input terminal, a signal output terminal, and a terminal for determining an output state (normal OE terminal: Out Enable terminal). Is provided. Hereinafter, an outline of the operations of the first and second selectors 301 and 302 will be described.

  Normally, in the case of an active low selector, when an L level signal is input to the OE terminal, a signal having the same level as the input terminal is output from the output terminal. For example, if the L level is input to the OE terminal and the H level is input to the input terminal, the H level is output to the output terminal. Conversely, when the L level is input, the L level is output. When an H level signal is input to the OE terminal, the output becomes high impedance regardless of the input level. For example, if the H level is input to the OE terminal and the H level is input to the input terminal, the output becomes high impedance.

  In the switching circuit 208, the circuit switching signal 209 is directly applied to the second selector 302 and simultaneously applied to the first selector 301 via the inverter 304. When the circuit switching signal 209 is at the H level, the L level is input to the OE terminal of the first selector 301, and the output is the same level as the input of the first selector 301, that is, the output of the IO circuit unit 206. It becomes. At this time, since the H level is input to the OE terminal of the second selector 302, the output has a high impedance.

  Therefore, as signal flow, signal information from the sheet detection unit 210 is first input to the IO circuit unit 206 and further input to the CPU circuit unit 202 for processing. Based on the processed information, a control signal of the display unit 211 is output from the CPU circuit unit 202 to the IO circuit unit 206 and transmitted to the display unit 211 via the driver 303. Conversely, when the circuit switching signal is at the L level, the output of the first selector 301 has a high impedance, and the output of the second selector 302 has the same level as the input, that is, the same level as the output of the paper detection unit 210. At this time, the output signal of the second selector 302 is transmitted to the display unit 211 via the driver 303. Here, the display unit 211 is driven using the driver 303, but if the selectors 301 and 302 can drive, there is no problem.

  As described above, it is possible to determine whether or not the paper presence / absence information detected by the paper detection unit 210 is transmitted to the display unit 211 via the control unit 201 based on the signal level of the circuit switching signal 209. For example, if the circuit switching signal 209 is determined in the power saving mode, the circuit switching signal 209 is H level when the power saving mode is not transferred, and the circuit switching signal 209 is L level when the power saving mode is shifted. The presence / absence information of the sheet detected by the sheet detection unit 210 when the power mode is not transferred is transmitted to the display unit 211 via the control unit 201, and the presence / absence information of the sheet detected by the sheet detection unit 210 is controlled when the mode is shifted to the power saving mode. It can be directly transmitted to the display unit 211 without going through the unit 201.

  FIG. 6 is a block diagram illustrating a specific example of the sheet detection unit 210 and the display unit 211 of FIG. That is, the first and second paper detection sensors 210-a and 210-b of the paper detection unit 210 are configured by first and second photo reflectors (reflection type optical sensors) 410-a and 410-b. The display unit 211 is composed of first and second LEDs 411-a and 411-b. The collectors of the phototransistors mounted in the first and second photoreflectors 410-a and 410-b are connected to the inputs of the second selector 302 and the IO circuit 206, and each emitter is connected to GND. It is connected. Each collector is pulled up by a power source (+5 VE) through a resistor.

  In such a configuration, when there is a sheet on the light emitting / receiving surface of the first and second photo reflectors 410-a and 410-b, the inside of the first and second photo reflectors 410-a and 410-b. The light of each LED is reflected on the paper surface and incident on the phototransistor, and the phototransistor is turned on. As a result, the collector and emitter become conductive, and the inputs of the second selector 302 and the IO circuit unit 206 are at the L level. Conversely, when there is no paper, LED light is not incident on the phototransistor, so that the phototransistor is turned off, and the inputs of the second selector 302 and the IO circuit unit 206 are at the H level.

  When the circuit switching signal 209 is at the H level, the outputs of the first and second photo reflectors 10-a and 410-b are input to the IO circuit unit 206, and then transmitted to the CPU circuit unit 202 and processed by the CPU 203. Thereafter, the light is transmitted again to the first and second LEDs 411-a and 411-b via the IO circuit unit 206. When the circuit switching signal 209 is at the L level, the output of the photo reflector 410 is directly transmitted to the first and second LEDs 411-a and 411-b. At this time, if there is a sheet in the light emitting / receiving section of the first and second photo reflectors 410-a and 410-b, the first and second LEDs 411-a and 411-b are lit and there is no sheet. In this case, both the first and second LEDs 411-a and 411-b are not lit.

  FIG. 7 is a block diagram illustrating a specific example of the main body control board 210, the paper detection unit 210, and the display unit 211 when the driving power supply 412 of the control unit 201 is used as the circuit switching signal 209. The control unit driving power source 412 supplies power to the CPU circuit unit 202 and the IO circuit unit 206 of the control unit 201 and also applies the circuit switching signal to the inverter 304 of the switching circuit 208. As a result, the circuit switching signal 209 can be automatically generated from the power supply state when the power saving mode is shifted / not shifted. In this case, the power sources of the first and second photo reflectors 410-a and 410-b, the first and second LEDs 411-a and 411-b, the first and second selectors 301 and 302, and the inverter 304 are as follows. It is necessary that the power supply is not stopped even when the power saving mode is shifted.

1 is a diagram illustrating a schematic configuration of an image forming apparatus including a sheet feeding device according to an embodiment of the present invention. FIG. 4 is a block diagram illustrating an electrical configuration of a sheet feeding device. It is a block diagram which shows the main body control board of FIG. 2 in detail. 6 is a flowchart for explaining the operation of the sheet feeding device in the present embodiment. FIG. 4 is a block diagram showing a specific example of the switching circuit of FIG. 3. FIG. 6 is a block diagram illustrating a specific example of a sheet detection unit and a display unit in FIG. 5. It is a block diagram which shows the specific example of a main body control board, a paper detection part, and a display part at the time of using the drive power supply of a control part as a circuit switching signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Paper discharge tray 120 Reading optical system 130 Writing optical system 136 Photosensitive drum 137 Developing roller 139 Paper feed roller 146 Registration roller 160 Image forming part 170 Paper feed part 180 Fixing part 190 Paper discharge part 200 Main body control board 201 Control part 208 Switching Circuit 210 Paper detection unit 210-a, 210-b Paper detection sensor 211 Display unit 211-a, 211-b Light emitting element 212 Operation unit 214 Power source 215 Timer count unit 202 CPU control unit 410-a, 410-b Photo reflector 411 -A, 411-b LED

Claims (9)

In a paper feeder equipped with a low power consumption mode,
Paper detection means for detecting the presence or absence of paper at a predetermined location in the paper transport path;
Display means for displaying the detection status of the paper detection means;
A time measuring means for measuring a preset time;
Control means for controlling each part of the device and each means;
Switching means for switching a signal transmission circuit between the paper detection means, the display means and the control means;
With
When the paper feeding operation is completed or interrupted, the time measuring means starts measuring from the time when the paper feeding operation is completed or interrupted.
The control means shifts to the low power consumption mode when the time set by the time measuring means passes the preset time,
The sheet feeding device, wherein the switching unit switches the signal transmission circuit to a predetermined signal path.   2. The sheet feeding device according to claim 1, wherein the predetermined signal path is a path for directly transmitting sheet presence / absence information transmitted from the sheet detection unit to the control unit to the display unit.   The sheet feeding device according to claim 1, further comprising an operation unit capable of arbitrarily setting a time measured by the timing unit after the sheet feeding operation is completed or interrupted.   4. The sheet feeding device according to claim 1, wherein a switching signal input to the switching unit is supplied from a driving power source of the control unit. 5.   The sheet feeding device according to claim 4, wherein the switching signal is automatically generated from a power supply state at the time of shifting to a power saving mode or not.   2. The sheet feeding device according to claim 1, wherein a plurality of the sheet detecting means are arranged at intervals in the sheet conveying direction of the sheet conveying path.   The sheet feeding device according to claim 1, wherein the sheet detection unit includes a photo reflector.   The sheet feeding device according to claim 1, wherein the display unit is an LED.   An image forming apparatus comprising the paper feeding device according to claim 1.

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