Paper characteristics detection device and image forming system

Abstract

To provide a paper characteristics detection device that can detect the opening and closing of a shutter. [Solution] The paper characteristic detection device of the present invention comprises a housing 41 provided with an opening 41H, a light-emitting unit 42 that emits light toward the opening, a light-receiving unit 44 that receives reflected light from the light-emitting unit, a shutter 45 that can switch between a closed state that closes the opening and an open state that opens the opening, and a drive mechanism 46 that drives the shutter. The paper characteristic detection device detects the characteristics of the paper by allowing light from the light-emitting unit to pass through the opening and incident on the paper, and having the light-receiving unit detect the reflected light that has been reflected by the paper and passed through the opening. The device also includes a detection unit that detects the opening and closing of the shutter by utilizing the phenomenon in which the shutter blocks light from the light-emitting unit or reflected light during the opening and closing of the shutter.

Description

Technical Field

[0001] The present invention relates to a paper property detection device and an image forming system.

Background Art

[0002] In order to provide high-quality printed matter by an image forming apparatus, it is necessary to recognize the properties of the paper used for printing and set printing parameters according to the properties of the paper.

[0003] In relation to this, Patent Document 1 below discloses a paper property detection device (sheet material discrimination device) that discriminates the type of paper by irradiating the paper with light and receiving the reflected light from the paper. The paper property detection device disclosed in Patent Document 1 irradiates the paper with light through an opening from a light emitting unit housed inside a housing provided with the opening, and detects the reflected light from the paper by a light receiving unit housed inside the housing, thereby discriminating the type of paper. The opening of the housing is opened and closed by a shutter. Usually, the shutter is in a closed state, and when irradiating the paper with light, the shutter shifts from the closed state to the open state.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the shutter may not normally shift from the closed state to the open state due to deterioration of the drive mechanism or changes in the environment (humidity / temperature). If the shutter does not normally shift from the closed state to the open state, the property value of the paper cannot be correctly detected, which is not preferable. Therefore, in the paper property detection device, it is desired to detect the opening and closing of the shutter.

[0006] This invention has been made in view of the above-mentioned problems. Therefore, the object of this invention is to provide a paper characteristic detection device that can detect the opening and closing of a shutter.

[0007] Another object of the present invention is to provide an image forming system equipped with the above-mentioned paper characteristic detection device. [Means for solving the problem]

[0008] The above objectives of the present invention are achieved by the following means.

[0009] (1) A paper characteristic detection device comprising: a housing provided with an opening; a light-emitting unit housed in the housing and emitting light toward the opening; a light-receiving unit housed in the housing and receiving reflected light emitted from the light-emitting unit; a shutter housed in the housing and capable of switching between a closed state that closes the opening and an open state that opens the opening; and a drive mechanism housed in the housing that drives the shutter, wherein the paper characteristic detection device detects the characteristics of the paper by allowing light from the light-emitting unit to pass through the opening and incident on the paper, and having the light-receiving unit detect the reflected light that has been reflected by the paper and passed through the opening, and further comprising a detection unit that detects the opening and closing of the shutter by utilizing the phenomenon in which the shutter blocks light from the light-emitting unit or reflected light of said light during the opening and closing of the shutter.

[0010] (2) After the opening operation of the shutter is instructed, if the shutter does not block the light from the light-emitting unit or the reflected light of said light, the detection unit detects that the shutter remains in the closed state and cannot transition to the open state, the paper characteristic detection device as described in (1) above.

[0011] (3) The paper characteristic detection device according to (1) or (2) above, wherein the detection unit detects the opening and closing of the shutter based on the detected value of the light receiving unit.

[0012] (4) The paper characteristic detection device according to (2) above, wherein if the difference between the light-receiving unit's detection value before the shutter opening operation is instructed and the light-receiving unit's detection value after a predetermined time has elapsed since the opening operation was instructed is less than or equal to a predetermined threshold, the detection unit detects that the shutter remains in the closed state and cannot transition to the open state.

[0013] (5) The paper characteristic detection device according to (1) or (2) above, further comprising a calibration plate provided on the side of the shutter that is on the light-emitting part side when it is in the closed state.

[0014] (6) The paper characteristic detection device according to (1) or (2) above, wherein the light receiving unit is composed of a plurality of light receiving units, and the detection unit detects the opening and closing of the shutter based on the detection value of one light receiving unit selected from the plurality of light receiving units.

[0015] (7) The paper characteristic detection device according to (1) or (2) above, wherein the light receiving unit is composed of a first light receiving unit that receives specularly reflected light from the paper and a second light receiving unit that receives diffusely reflected light from the paper, and the detection unit detects the opening and closing of the shutter based on the detection value of the second light receiving unit.

[0016] (8) The paper characteristic detection device according to (2) above, wherein, after the operation to open the shutter is instructed, the detection unit detects that the shutter remains in the closed state and cannot transition to the open state, the operation to open the shutter is instructed again, and the operation to detect the opening and closing of the shutter is repeated.

[0017] (9) The paper characteristic detection device according to (8) above, wherein if the detection unit detects that the shutter has transitioned from a closed state to an open state before the operation is repeated a predetermined number of times, an operation for detecting the paper characteristics is performed, and if the operation is repeated a predetermined number of times but the detection unit does not detect that the shutter has transitioned from a closed state to an open state, an abnormality is reported.

[0018] (10) The housing is provided on the discharge path of the paper. When the detection unit detects that the shutter cannot shift from the closed state to the open state, only the discharge of the paper is performed. The paper characteristic detection device according to (2) above.

[0019] (11) When an abnormality other than the opening / closing abnormality of the shutter is detected, the abnormality is notified so as to be distinguishable from the opening / closing abnormality of the shutter. The paper characteristic detection device according to (1) or (2) above.

[0020] (12) The abnormality other than the opening / closing abnormality of the shutter includes the abnormality of the light emitting unit. The paper characteristic detection device according to (11) above.

[0021] (13) An image forming system including the paper characteristic detection device according to (1) or (2) above.

Advantages of the Invention

[0022] According to the present invention, the opening and closing of the shutter are detected.

Brief Description of the Drawings

[0023] The advantages and features provided by one or more embodiments of the present invention will be more fully understood from the following detailed description and the accompanying drawings, which are for illustrative purposes only and are not intended to define the limitation of the present invention. [Figure 1] It is a diagram showing a schematic configuration of an image forming system. [Figure 2] It is a schematic diagram showing a schematic configuration of a paper characteristic detection unit. [Figure 3] It is a perspective view showing a schematic configuration of a paper characteristic detection unit. [Figure 4] It is a cross-sectional view taken along line IV-IV in FIG. 3 [Figure 5] It is a timing chart showing the operations of each part of the paper characteristic detection unit. [Figure 6A] It is a schematic diagram for explaining the operations of each part of the paper characteristic detection unit. [Figure 6B]This figure follows Figure 6A. [Figure 6C] This figure follows Figure 6B. [Figure 7] This flowchart shows the procedure for detecting paper characteristics. [Figure 8] This figure shows an example of an abnormality notification screen. [Figure 9] This figure shows another example of an anomaly notification screen. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described below with reference to the drawings. However, the scope of the present invention is not limited to the disclosed embodiments.

[0025] In the description of the drawings, the same elements are denoted by the same reference numeral, and redundant explanations are omitted. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios. Furthermore, the paper in this embodiment includes printing paper and various films. In particular, printing paper includes paper manufactured using plant-derived mechanical pulp and / or chemical pulp. The types of paper include gloss paper, matte paper, plain paper, high-gloss paper, coated paper, etc.

[0026] Figure 1 is a diagram showing the schematic configuration of an image forming system 1 according to one embodiment of the present invention.

[0027] As shown in Figure 1, the image forming system 1 includes an image forming apparatus 10, a paper feeder 20, and a paper characteristics detection device 30. The devices are connected in the order of paper feeder 20, paper characteristics detection device 30, and image forming apparatus 10, along the transport direction of the paper 90 fed from the paper feeder 20.

[0028] <Image forming apparatus 10> The image forming apparatus 10 comprises a control unit 11, a storage unit 12, a communication unit 13, an operation display unit 14, a paper feeding unit 15, a transport unit 16, an image forming unit 17, and a fixing unit 18. Each of these units is interconnected via a bus for exchanging signals.

[0029] The control unit 11 includes a CPU (Central Processing Unit) and performs control of the above-mentioned parts and various calculation processes according to the program.

[0030] The memory unit 12 consists of a ROM (Read Only Memory) for pre-storing various programs and data, a RAM (Random Access Memory) for temporarily storing programs and data as a working area, and a hard disk for storing various programs and data.

[0031] The communication unit 13 is an interface for communicating with other devices. For example, the communication unit 13 transmits and receives various data and signals with the paper feed device 20 and the paper characteristics detection device 30.

[0032] The operation display unit 14 is equipped with a touch panel, a numeric keypad, a start button, a stop button, etc., and is used for displaying various information and inputting various instructions.

[0033] The paper feed unit 15 is equipped with paper trays for storing the paper 90 used for printing, and feeds one sheet of paper 90 at a time from each paper tray.

[0034] The transport unit 16 includes a transport path 161, a plurality of transport roller pairs 162, and a drive motor (not shown) that drives the transport roller pairs 162, and transports the paper 90 fed from the paper feed device 20 or the paper feed unit 15 along the transport path 161.

[0035] The image forming unit 17 forms an image on the paper 90 fed from the paper feeder 20 or on the paper 90 fed from the paper feed unit 15. The image forming unit 17 forms an image on the paper 90 using, for example, a well-known electrophotographic image formation process that includes the steps of charging, exposure, development, and transfer.

[0036] The fixing unit 18 includes a heating roller and a pressure roller that are heated by a heater, and heats and pressurizes the paper 90 on which the image has been formed by the image forming unit 17 to fix the image to the paper 90.

[0037] <Paper feeder 20> The paper feeder 20 comprises a control unit 21, a storage unit 22, a communication unit 23, a paper feeding unit 24, and a transport unit 25. These units are interconnected via a bus for exchanging signals. Note that the units of the paper feeder 20 have the same functions as the units of the image forming apparatus 10, so their description is omitted.

[0038] <Paper characteristics detection device 30> The paper characteristics detection device 30 comprises a control unit 31, a storage unit 32, a communication unit 33, a paper characteristics detection unit 34, a transport unit 35, and a paper discharge unit 36. These units are interconnected via a bus for exchanging signals. The parts of the paper characteristics detection device 30 that have the same functions as those of the image forming apparatus 10 will not be described.

[0039] The paper characteristics detection unit 34 detects the characteristics of the paper 90. The paper characteristics detection unit 34 is located in a transport path (discharge path) that branches upward from the transport path of the paper 90 fed from the paper feed device 20 to the image forming apparatus 10, and detects the characteristics of the paper 90 transported to the discharge path. The paper characteristics detection unit 34 detects the characteristics of the paper 90 by irradiating the paper 90 with light and detecting the reflected light. A detailed explanation of the paper characteristics detection unit 34 will be given later.

[0040] The paper output unit 36 ​​is equipped with a paper output tray that discharges the paper 90 that has been transported along the output path, and discharges the paper 90 that has passed through the paper characteristics detection unit 34 to the outside.

[0041] The storage unit 32 of the paper characteristics detection device 30 stores a discrimination program for determining the type of paper, and a detection program for detecting the opening and closing of the shutter 45 (see Figure 3) of the paper characteristics detection unit 34. The control unit 31 of the paper characteristics detection device 30 functions as a detection unit that detects the opening and closing of the shutter 45 of the paper characteristics detection unit 34 by executing the above detection program. The control unit 31 of the paper characteristics detection device 30 also includes drive circuits and signal processing circuits for driving the various parts of the paper characteristics detection unit 34, which will be described later.

[0042] The image forming apparatus 10, the paper feeding device 20, and the paper characteristic detection device 30 may include components other than those described above, or may not include some of the components described above.

[0043] <Paper characteristics detection unit 34> Next, with reference to Figures 2 to 4, the paper characteristic detection unit 34 of the paper characteristic detection device 30 will be described in detail.

[0044] Figure 2 is a schematic diagram showing the general configuration of the paper characteristic detection unit 34, and Figure 3 is a perspective view showing the general configuration of the paper characteristic detection unit 34. Figure 4 is a cross-sectional view along the line IV-IV in Figure 3.

[0045] As shown in Figures 2 to 4, the paper characteristic detection unit 34 comprises a housing 41, a light-emitting unit 42, a first light-receiving unit 43, a second light-receiving unit 44, a shutter 45, a drive mechanism 46, and a calibration plate 47.

[0046] The housing 41 houses the light-emitting unit 42, the first light-receiving unit 43, the second light-receiving unit 44, the shutter 45, the drive mechanism 46, and the calibration plate 47. The housing 41 has a roughly box-like shape and consists of a bottom 411 and a lid 412 that covers the bottom 411. An opening 41H is provided in the bottom 411. The opening 41H is positioned to face the transport path through which the paper 90 is transported.

[0047] The light-emitting unit 42 emits light toward the opening 41H of the housing 41. The light-emitting unit 42 is positioned such that its optical axis is tilted at a first angle α (for example, 75 degrees) with respect to a reference axis AX perpendicular to the bottom 411 of the housing 41, and it illuminates the opening 41H at an oblique angle. The light-emitting unit 42 is, for example, an LED (Light Emitting Diode) and is controlled by PWM (Pulse Width Modulation) by the control unit 31 of the paper characteristic detection device 30. When the opening 41H is open, the light from the light-emitting unit 42 passes through the opening 41H and enters the paper 90.

[0048] The first light-receiving unit 43 receives reflected light from the light-emitting unit 42. The first light-receiving unit 43 is, for example, a photodiode, and is positioned such that its optical axis is tilted at a first angle α (for example, 75 degrees) with respect to a reference axis AX that is perpendicular to the bottom 411 of the housing 41. When the aperture 41H is open, the first light-receiving unit 43 receives specularly reflected light that is specularly reflected by the paper 90 and passes through the aperture 41H.

[0049] The second light-receiving unit 44 receives reflected light from the light-emitting unit 42. The second light-receiving unit 44 is, for example, a photodiode, and is positioned such that its optical axis is tilted at a second angle β (for example, 30 degrees) with respect to a reference axis AX that is perpendicular to the bottom 411 of the housing 41. When the aperture 41H is open, the second light-receiving unit 44 receives diffusely reflected light that is diffusely reflected by the paper 90 and passes through the aperture 41H.

[0050] The optical axes of the light-emitting unit 42, the first light-receiving unit 43, and the second light-receiving unit 44 are arranged on the same plane including the reference axis AX. The control unit 31 of the paper characteristic detection device 30 determines the type of paper 90 based on the detection values ​​of the first and second light-receiving units 43 and 44. With this configuration, the type of paper 90 is determined using the detection values ​​of the two light-receiving units 43 and 44, so the accuracy of determining the type of paper 90 is improved compared to when only the detection value of one light-receiving unit is used.

[0051] The shutter 45 is configured to switch between a closed state, which closes the opening 41H of the housing 41, and an open state, which opens the opening 41H. The shutter 45 is rotated by the drive mechanism 46 to switch between the closed state and the open state. Normally, the shutter 45 is in the closed state, and when the paper characteristic detection unit 34 detects the characteristics of the paper 90, the shutter 45 transitions from the closed state to the open state. The shutter 45 can be in two open states. That is, it can be in a first open state (dashed line in Figure 4) where the shutter 45 is rotated by an angle greater than a predetermined value relative to the bottom 411, and a second open state (dotted line in Figure 4) where the shutter 45 is rotated by an angle less than a predetermined value relative to the bottom 411. When the paper characteristic detection unit 34 detects the characteristics of the paper 90, the shutter 45 enters the first open state and the opening 41H is fully open.

[0052] The drive mechanism 46 drives the shutter 45. The drive mechanism 46 includes, for example, a stepping motor and rotates the shutter 45 around a rotation axis parallel to the bottom 411 of the housing 41. The drive mechanism 46 is controlled by the control unit 31 of the paper characteristics detection device 30. Note that the shutter 45 may not open or close properly due to deterioration of the drive mechanism 46 or changes in the environment (humidity / temperature). For example, the shutter 45 or drive mechanism 46 may expand due to a rise in temperature, preventing the shutter 45 from opening properly.

[0053] The calibration plate 47 is provided on the inner surface of the shutter 45. The calibration plate 47 is for calibrating the paper characteristic detection unit 34 and is a plate having a predetermined degree of smoothness, such as a white resin. The calibration plate 47 is positioned so that, in the closed state when the shutter 45 closes the opening 41H, it specularly reflects the light emitted from the light-emitting unit 42 toward the first light-receiving unit 43 and diffusely reflects it toward the second light-receiving unit 44. Note that the state of the light emitted from the light-emitting unit 42 (light quantity, etc.) changes over time and due to environmental influences, so it is calibrated periodically. In this embodiment, the paper characteristic detection unit 34 is calibrated by adjusting the light emission conditions, etc., based on the optical information of the reflected light reflected by the calibration plate 47.

[0054] <Detection of opening and closing of shutter 45> Next, with reference to Figures 5 and 6, the operation of the paper characteristic detection device 30, which detects the opening and closing of the shutter 45, will be described. When the paper characteristic detection device 30 detects the characteristics of the paper 90, it detects when the shutter 45 transitions normally from the closed state to the open state. The paper characteristic detection device 30 detects the opening and closing of the shutter 45 based on the detection value of the second light receiving unit 44.

[0055] Figure 5 is a timing chart showing the operation of each part of the paper characteristics detection unit 34 when the shutter 45 transitions from the closed state to the open state. Figures 6A to 6C are schematic diagrams illustrating the operation of each part during each period of the timing chart.

[0056] In Figure 5, the shutter drive signal is a signal that controls the opening operation of the shutter 45, and the LED drive signal is a signal that controls the light emission operation of the light-emitting unit 42. The second light-receiving unit signal is an output signal that indicates the amount of light received (detected value) of the second light-receiving unit 44.

[0057] As shown in Figure 5, first, during the first period P1 from the first time point T1 to the second time point T2, an LED drive signal (pulse signal) is generated, and the light-emitting unit 42 emits light. The light emitted from the light-emitting unit 42 is reflected by the calibration plate 47 and reaches the second light-receiving unit 44.

[0058] During the first period P1, the detection value (AD conversion value of the output signal) of the second light receiving unit 44 is acquired multiple times, and the average value of the multiple detection values ​​is calculated as the first detection value ADA of the second light receiving unit 44. The first detection value ADA of the second light receiving unit 44 is stored in the storage unit 32 of the paper characteristic detection device 30 as information for detecting the opening and closing of the shutter 45. The first period P1 is, for example, 55 milliseconds.

[0059] Subsequently, at the third time point T3, a shutter drive signal (pulse signal) and an LED drive signal are generated simultaneously. The generation of the shutter drive signal (pulse signal) drives the drive mechanism 46, causing the shutter 45 to rotate (open). The opening degree of the shutter 45 increases over time. In addition, the generation of the LED drive signal again causes the light-emitting unit 42 to continue emitting light from the third time point T3 onward.

[0060] During the second period P2, from the third time point T3 to the fourth time point T4, as shown in Figure 6A, the light emitted from the light-emitting unit 42 is reflected by the calibration plate 47 and reaches the second light-receiving unit 44. However, as time progresses and the opening of the shutter 45 increases, the amount of light reflected by the calibration plate 47 and reaching the second light-receiving unit 44 decreases, and the amount of light received by the second light-receiving unit 44 decreases. At the fourth time point T4, the amount of light received by the second light-receiving unit 44 becomes virtually zero. The second period P2 is, for example, 75 milliseconds.

[0061] During the third period P3, from the fourth time point T4 to the fifth time point T5, as shown in Figure 6B, the light emitted from the light-emitting unit 42 and its reflected light are blocked by the shutter 45, and no light reaches the second light-receiving unit 44. Therefore, during the third period P3, although the opening of the shutter 45 increases with the passage of time, the amount of light received by the second light-receiving unit 44 remains virtually zero.

[0062] During the third period P3, the detection value (AD conversion value of the output signal) of the second light receiving unit 44 is acquired multiple times, and the average value of the multiple detection values ​​is calculated as the second detection value ADB of the second light receiving unit 44. The second detection value ADB of the second light receiving unit 44 is stored in the storage unit 32 of the paper characteristic detection device 30 as information for detecting the opening and closing of the shutter 45. The third period P3 is, for example, 55 milliseconds.

[0063] Subsequently, at the fifth time point T5, once the shutter 45 reaches a specific opening, the light emitted from the light-emitting unit 42 passes through the aperture 41H and enters the surface of the paper 90. The light reflected from the surface of the paper 90 then passes through the aperture 41H and reaches the second light-receiving unit 44. As a result, at the fifth time point T5, the amount of light received by the second light-receiving unit 44 begins to increase.

[0064] During the period from the fifth time point T5 onward, as shown in Figure 6C, the light emitted from the light-emitting unit 42 is reflected by the paper 90 and reaches the second light-receiving unit 44. As time progresses and the opening of the shutter 45 increases, the amount of light reaching the second light-receiving unit 44 increases. The amount of light received by the second light-receiving unit 44 continues to increase until the aperture 41H is almost fully open.

[0065] As described above, in the paper characteristic detection device 30 of this embodiment, when the shutter 45 transitions normally from the closed state to the open state, a phenomenon occurs in which the shutter 45 temporarily blocks light (the optical path of the second light receiving unit 44) during the opening operation of the shutter 45, as shown in Figure 6B. Therefore, after the opening operation of the shutter 45 is instructed, when the shutter 45 transitions normally from the closed state to the open state, the amount of light received by the second light receiving unit 44 temporarily becomes zero during the third period P3 described above.

[0066] On the other hand, in the paper characteristic detection device 30 of this embodiment, if there is an abnormality in the shutter 45 and the shutter 45 remains in the closed state and cannot transition to the open state, the phenomenon of the shutter 45 temporarily blocking light does not occur. Therefore, if the shutter 45 remains in the closed state and cannot transition to the open state after the opening operation of the shutter 45 has been instructed, the amount of light received by the second light receiving unit 44 in the third period P3 is not substantially zero, but shows substantially the same value as the amount of light received in the first period P1.

[0067] Therefore, the paper characteristic detection device 30 of this embodiment detects the opening and closing of the shutter 45 by comparing the first detected value ADA of the second light receiving unit 44 in the first period P1 with the second detected value ADB of the second light receiving unit 44 in the third period P3. Specifically, if the difference between the first detected value ADA and the second detected value ADB exceeds a predetermined threshold, the paper characteristic detection device 30 detects that the shutter 45 has successfully transitioned from a closed state to an open state. On the other hand, if the difference between the first detected value ADA and the second detected value ADB is less than or equal to a predetermined threshold, the paper characteristic detection device 30 detects that the shutter 45 remains in a closed state and cannot transition to an open state.

[0068] <Paper characteristics detection process> Next, the operation of the paper characteristic detection device 30, which detects the characteristics of the paper, will be described with reference to Figures 7 and 8. Figure 7 is a flowchart showing the procedure for the paper characteristic detection process. The process shown in the flowchart in Figure 7 is executed by the control unit 31 according to the program stored in the storage unit 32 of the paper characteristic detection device 30.

[0069] (Step S101) First, the paper characteristics detection device 30 determines whether or not there is an instruction to start measuring the paper characteristics. More specifically, the paper characteristics detection device 30 determines, for example, whether or not it has received a signal from the image forming apparatus 10 instructing it to start measuring the paper characteristics.

[0070] If it is determined that there is no instruction to start measuring paper characteristics (step S101: NO), the paper characteristics detection device 30 waits until an instruction to start measuring paper characteristics is received. On the other hand, if it is determined that there is an instruction to start measuring paper characteristics (step S101: YES), the paper characteristics detection device 30 proceeds to the process in step S102.

[0071] (Step S102) If it is determined that there is an instruction to start measuring the paper characteristics (step S101: YES), the paper characteristics detection device 30 acquires the first detected value of the second light receiving unit 44. More specifically, the paper characteristics detection device 30 generates an LED drive signal to make the light-emitting unit 42 emit light, and at the same time acquires the first detected value ADA by averaging multiple detected values ​​of the second light receiving unit 44. Prior to acquiring the first detected value ADA, the light intensity of the light-emitting unit 42 can be calibrated based on the detected value of the first light receiving unit 43 or the second light receiving unit 44.

[0072] (Step S103) Next, the paper characteristics detection device 30 instructs the shutter 45 to open. More specifically, the paper characteristics detection device 30 generates a shutter drive signal (pulse signal) to operate the drive mechanism 46. If there is no abnormality in the shutter 45 or the drive mechanism 46, the shutter 45 starts to open. On the other hand, if there is an abnormality in the shutter 45 or the drive mechanism 46, the shutter 45 does not start to open and remains closed.

[0073] (Step S104) Next, the paper characteristics detection device 30 determines whether a predetermined time has elapsed. More specifically, the paper characteristics detection device 30 determines whether a predetermined time (for example, 75 milliseconds) has elapsed since the shutter 45 was instructed to open in step S103. Here, the predetermined time is the time during which the shutter 45 blocks light (see Figure 6B) while it is opening, and the amount of light received by the second light receiving unit 44 becomes substantially zero. The predetermined time corresponds to the second period P2 in Figure 5.

[0074] If it is determined that the predetermined time has not elapsed (Step S104: NO), the paper characteristics detection device 30 waits until the predetermined time has elapsed. On the other hand, if it is determined that the predetermined time has elapsed (Step S104: YES), the paper characteristics detection device 30 proceeds to the process in Step S105.

[0075] (Step S105) If it is determined that a predetermined time has elapsed (step S104: YES), the paper characteristic detection device 30 acquires the second detection value of the second light receiving unit 44. More specifically, the paper characteristic detection device 30 generates an LED drive signal to make the light-emitting unit 42 emit light, and at the same time, averages the multiple detection values ​​of the second light receiving unit 44 to acquire the second detection value ADB. As described above, if the shutter 45 is opening normally, the second detection value ADB is substantially zero. On the other hand, if the shutter 45 does not open and remains closed, the second detection value ADB is substantially the same as the first detection value ADA.

[0076] (Step S106) Next, the paper characteristic detection device 30 determines whether the difference between the detected values ​​of the second light receiving unit 44 is greater than a predetermined threshold. More specifically, the paper characteristic detection device 30 determines whether the difference between the first detected value ADA obtained in step S102 and the second detected value ADB obtained in step S105 is greater than a predetermined threshold. The predetermined threshold is set, for example, based on experiments.

[0077] If the difference in the detected values ​​of the second light receiving unit 44 is determined to be greater than a predetermined threshold (step S106: YES), the paper characteristic detection device 30 determines that the shutter 45 has transitioned normally from the closed state to the open state and proceeds to the process of step S110. On the other hand, if the difference in the detected values ​​of the second light receiving unit 44 is determined to be less than or equal to a predetermined threshold (step S106: NO), the paper characteristic detection device 30 determines that the shutter 45 remains in the closed state and proceeds to the process of step S107.

[0078] (Step S107) If the difference in the detected values ​​of the second light receiving unit 44 is determined to be less than or equal to a predetermined threshold (step S106: NO), the paper characteristic detection device 30 determines whether the instruction to open the shutter 45 has been given a predetermined number of times. More specifically, the paper characteristic detection device 30 determines, for example, whether the instruction to open the shutter 45 has been given three times.

[0079] If the paper characteristic detection device 30 determines that the instruction to open the shutter 45 has been given a predetermined number of times (step S107: YES), the paper characteristic detection device 30 proceeds to the process in step S109. On the other hand, if the paper characteristic detection device 30 determines that the instruction to open the shutter 45 has not been given a predetermined number of times (step S107: NO), the paper characteristic detection device 30 proceeds to the process in step S108.

[0080] (Step S108) If the paper characteristic detection device 30 determines that the instruction to open the shutter 45 has not been given a predetermined number of times (step S107: NO), the paper characteristic detection device 30 instructs the shutter 45 to close and returns to the process in step S102. More specifically, the paper characteristic detection device 30 first waits for the time required for the opening operation of the shutter 45 to be completed (for example, 256 milliseconds), then waits for a certain period of time (500 milliseconds), before generating a shutter drive signal and instructing the shutter 45 to close. Furthermore, the paper characteristic detection device 30 waits for the time required for the closing operation to be completed (for example, 256 milliseconds), then waits for a certain period of time (500 milliseconds), before returning to the process in step S102. As a result, the processes in steps S102 to S108 are repeated until the process in step S106 determines that the difference in the detected values ​​of the second light receiving unit 44 is below a predetermined threshold, or until the process in step S107 determines that the instruction to open has been given a predetermined number of times.

[0081] (Step S109) On the other hand, if the paper characteristic detection device 30 determines that the instruction to open the shutter 45 has been given a predetermined number of times during the process in step S107 (step S107: YES), it notifies the device of an abnormality and terminates the process. More specifically, the paper characteristic detection device 30 displays an abnormality notification screen 110 (see Figure 8) indicating that the shutter 45 remains in the closed state and cannot transition to the open state, for example, on the operation display unit 14 of the image forming apparatus 10, and terminates the process.

[0082] In this embodiment of the image forming system 1, even if the shutter 45 remains closed and cannot be moved to the open state, the paper 90 that has been transported to the paper characteristic detection unit 34 is discharged to the outside from the paper discharge unit 36.

[0083] (Step S110) On the other hand, in the process of step S106, if it is determined that the difference in the detected values ​​of the second light receiving unit 44 is greater than a predetermined threshold (step S106: YES), the paper characteristic detection device 30 determines the type of paper 90. More specifically, the paper characteristic detection device 30 generates an LED drive signal to make the light-emitting unit 42 emit light, and acquires the detected values ​​of the first and second light receiving units 43 and 44, and determines the type of paper 90 based on these detected values.

[0084] (Step S111) Then, the paper characteristic detection device 30 instructs the shutter 45 to close and terminates the process. More specifically, the paper characteristic detection device 30 generates a shutter drive signal, instructs the shutter 45 to close, and terminates the process. As a result, the shutter 45 moves from the open state to the closed state, and the opening 41H of the housing 41 is closed.

[0085] As described above, according to the flowchart shown in Figure 7, when the characteristics of the paper are detected, the shutter 45 transitions from the closed state to the open state. At this time, based on the change in the amount of light received (detected value) of the second light receiving unit 44, it is detected that the shutter 45 has successfully transitioned from the closed state to the open state. If it is not detected that the shutter 45 has successfully transitioned from the closed state to the open state, the shutter 45 is repeatedly instructed to open. If, even after the instruction is repeated a predetermined number of times, it is not detected that the shutter 45 has transitioned from the closed state to the open state, the user is notified of an abnormality.

[0086] As described above, the paper characteristic detection device 30 of this embodiment detects that the shutter 45 has transitioned normally from a closed state to an open state by utilizing the phenomenon in which the shutter 45 blocks the light emitted from the light-emitting unit 42 or its reflected light during the opening operation of the shutter 45. With this configuration, the operation to detect the characteristics of the paper 90 is performed when the opening 41H is reliably open, so that the characteristic values ​​of the paper 90 can be correctly detected.

[0087] Furthermore, according to the paper characteristic detection device 30 of this embodiment, the opening and closing of the shutter 45 is detected using a configuration (light-emitting unit 42, first and second light-receiving units 43, 44) for detecting the characteristics of the paper 90. With such a configuration, the configuration (or light) for detecting the characteristics of the paper 90 is also used for detecting the opening and closing of the shutter 45, so the opening and closing of the shutter 45 can be detected without adding any new configurations.

[0088] In this embodiment, if the paper characteristic detection device 30 detects an abnormality other than a shutter opening / closing abnormality, such as the light-emitting unit 42 not emitting light, a different abnormality notification screen from the one used to notify of a shutter opening / closing abnormality is displayed, and the user is notified accordingly. Specifically, for example, as shown in Figure 9, an abnormality notification screen 120 indicating that the LED constituting the light-emitting unit is not emitting light is displayed on the operation display unit 14 of the image forming apparatus 10. With this configuration, users of the image forming system 1 can distinguish and recognize various abnormalities that occur in the paper characteristic detection device 30.

[0089] The present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the claims.

[0090] For example, in the embodiment described above, the opening and closing of the shutter 45 was detected based on the detection value of the second light receiving unit 44. However, unlike the embodiment described above, the opening and closing of the shutter 45 may be detected based on the detection value of the first light receiving unit 43.

[0091] Furthermore, in the above-described embodiment, the case in which the shutter 45 has transitioned normally from a closed state to an open state after being instructed to open was described as an example. However, shutter opening and closing detection is not limited to detecting when the shutter has transitioned from a closed state to an open state; it may also be detected when the shutter has transitioned normally from an open state to a closed state after being instructed to close. In this case, the transition of the shutter 45 from an open state to a closed state is detected by utilizing the phenomenon in which the shutter 45 blocks the light emitted from the light-emitting unit 42 or its reflected light during the closing operation of the shutter 45.

[0092] Furthermore, in the embodiment described above, the housing 41 of the paper characteristic detection unit 34 is positioned to face the center of the paper 90 being transported along the transport path. However, unlike the embodiment described above, the housing 41 of the paper characteristic detection unit 34 may be configured to be movable according to the position of the paper 90. Also, a light source other than an LED may be used for the light-emitting unit 42 of the paper characteristic detection unit 34. For example, if a white light source is used as the light-emitting unit 42, the light-receiving units 43 and 44 may receive white light, or light of a characteristic wavelength extracted from the white light may be selectively received.

[0093] Furthermore, in the above-described embodiment, the paper characteristic detection device 30 was provided separately from the image forming apparatus 10 and the paper feed device 20. However, the paper characteristic detection device 30 may be provided integrally with the image forming apparatus 10, or integrally with the paper feed device 20.

[0094] The processing units in the flowcharts of the embodiments described above are divided according to the main processing content in order to facilitate understanding of each process. The present invention is not limited by how the processing steps are classified. Each process can be further divided into more processing steps. Also, one processing step may perform even more processes.

[0095] The means and methods for performing various processing in the image forming system 1 according to the above embodiment can be implemented by either a dedicated hardware circuit or a programmed computer. The program may be provided, for example, on a computer-readable recording medium such as a USB (Universal Serial Bus) memory or a DVD (Digital Versatile Disc)-ROM, or it may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. Furthermore, the program may be provided as a standalone application software, or it may be incorporated into the software of the image forming system 1 as a function of the device.

[0096] While embodiments of the present invention have been described and illustrated in detail, the disclosed embodiments are for illustrative purposes only and are not limiting. The scope of the present invention should be interpreted in accordance with the language of the appended claims. [Explanation of symbols]

[0097] 1. Image forming system, 10 Image forming apparatus, 11,21,31 Control Unit, 12,22,32 storage section, 13, 23, 33 Communications Department, 14 Operation display section, 15,24 Paper feed section, 16, 25, 35 Conveyor section, 17 Image forming unit, 18 Fixing section, 20 Paper feeder, 30. Paper characteristics detection device, 34 Paper characteristics detection unit, 36 Paper output section, 41 cabinets, 41H opening, 411 bottom, 412 Lid, 42 Light-emitting part, 43,44 Light receiving part, 45 shutters, 46 Drive mechanism, 47 Calibration plate, 90 sheets of paper.

Claims

1. A housing with an opening, A light-emitting unit housed in the aforementioned housing and emitting light toward the aforementioned opening, A light receiving unit is housed in the aforementioned housing and receives reflected light emitted from the light-emitting unit, A shutter housed in the aforementioned housing, which can switch between a closed state that closes the opening and an open state that opens the opening, The housing is housed in the aforementioned housing and includes a drive mechanism for driving the shutter, A paper characteristic detection device that detects the characteristics of the paper by allowing light from the light-emitting unit to pass through the opening and be incident on the paper, and having the reflected light that has been reflected by the paper and passed through the opening be detected by the light-receiving unit, A paper characteristic detection device having a detection unit that detects the opening and closing of the shutter by utilizing the phenomenon in which the shutter blocks light from the light-emitting unit or reflected light of said light while the shutter is opening and closing.

2. The paper characteristic detection device according to claim 1, wherein, after the opening operation of the shutter is instructed, if the shutter does not block the light from the light-emitting unit or the reflected light of said light, the detection unit detects that the shutter remains in the closed state and cannot transition to the open state.

3. The paper characteristic detection device according to claim 1 or 2, wherein the detection unit detects the opening and closing of the shutter based on the detected value of the light receiving unit.

4. The paper characteristic detection device according to claim 2, wherein if the difference between the light-receiving unit's detection value before the shutter opening operation is instructed and the light-receiving unit's detection value after a predetermined time has elapsed since the opening operation was instructed is less than or equal to a predetermined threshold, the detection unit detects that the shutter remains in the closed state and cannot transition to the open state.

5. The paper characteristic detection device according to claim 1 or 2, further comprising a calibration plate provided on the side of the shutter that is on the light-emitting part side when the shutter is in the closed state.

6. The light-receiving unit is composed of a plurality of light-receiving units, The paper characteristic detection device according to claim 1 or 2, wherein the detection unit detects the opening and closing of the shutter based on the detection value of one light-receiving unit selected from the plurality of light-receiving units.

7. The light-receiving unit is composed of a first light-receiving unit that receives specularly reflected light from the paper and a second light-receiving unit that receives diffusely reflected light from the paper. The paper characteristic detection device according to claim 1 or 2, wherein the detection unit detects the opening and closing of the shutter based on the detection value of the second light receiving unit.

8. The paper characteristic detection device according to claim 2, wherein, after the operation to open the shutter is instructed, if the detection unit detects that the shutter remains in the closed state and cannot transition to the open state, the operation to open the shutter is instructed again, and the operation to detect the opening and closing of the shutter is repeated.

9. If the detection unit detects that the shutter has transitioned from a closed state to an open state before the above operation is repeated a predetermined number of times, an operation to detect the characteristics of the paper is performed. The paper characteristic detection device according to claim 8, wherein if the detection unit does not detect that the shutter has transitioned from a closed state to an open state even after the operation described above has been repeated a predetermined number of times, an abnormality is reported.

10. The housing is provided on the paper discharge path, The paper characteristic detection device according to claim 2, wherein if the detection unit detects that the shutter remains closed and cannot transition to the open state, only the paper is ejected.

11. The paper characteristic detection device according to claim 1 or 2, wherein if an abnormality other than an abnormality in opening and closing of the shutter is detected, the abnormality is reported in a manner that can be distinguished from the abnormality in opening and closing of the shutter.

12. The paper characteristic detection device according to claim 11, wherein abnormalities other than abnormalities in the opening and closing of the shutter include abnormalities in the light-emitting unit.

13. An image forming system comprising a paper characteristic detection device according to claim 1 or 2.

Images