Image forming apparatus

Abstract

To provide an image forming apparatus that can omit special opening and closing detection means that detects an opening and closing state of an opening and closing cover, and is advantageous in terms of cost and space.SOLUTION: A document detection sensor 25B enters a light blocking state in which emitted light is blocked when a light blocking body 25d is at a light blocking position where it blocks light emitted from a light emitting unit to a light receiving unit of the document detection sensor 25B, and enters a light receiving state in which the emitted light is received when the light blocking body 25d is at a light receiving position where it can receive the light emitted from the light emitting unit to the light receiving unit of the document detection sensor 25B. When the document detection sensor 25B is in the light receiving state, a control unit determines that an opening and closing cover 24 is in an opened state or determines that the opening and closing cover 24 is in a closed state and a document 3 is not placed on a document tray 23, and when the document detection sensor is in the light blocking state, determines that the opening and closing cover 24 is in the closed state and the document 3 is placed on the document tray 23.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present disclosure relates to an image forming apparatus including a document feeder having a document tray on which a document is set, a document set detection section which detects that the document has been set in the document tray, and a pickup unit which has a pickup roller which sends the document set in the document tray downstream of a document transport path, and a control section which controls the document feeder. [Background technology]

[0002] The image forming apparatus disclosed in Patent Document 1 discloses that an open / close detection unit 30 and an original set detection unit 38 are provided in the apparatus body, and detected portions 30a, 38a are provided in the upper cover 29.

[0003] When both the open / close detection means 30 and the document set detection means 38 are ON, it is determined that the upper cover 29 is closed and no jam has occurred. Note that the reference numerals for each component in the description of the background art are those described in Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-191630 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional image forming devices were equipped with a dedicated opening / closing detection means 30 for detecting the open / closed state of the upper cover 29 (the opening / closing cover in this application), which required costs for the opening / closing detection means 30 and space for installing the opening / closing detection means 30.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an image forming apparatus that is advantageous in terms of cost and space by eliminating the need for a dedicated open / close detection means for detecting the open / close state of an open / close cover as in conventional image forming apparatuses. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, an image forming apparatus according to the present disclosure is an image forming apparatus including: an original tray on which an original is set; an original set detection section which detects that the original has been set on the original tray; an original feeder having a pickup unit including a pickup roller which sends the original set on the original tray to a downstream side of an original transport path; and a control section which controls the original feeder, wherein the original set detection section is provided on an opening / closing cover which is provided above the original tray and can be opened and closed, and includes an original detection lever which is in a detection standby position for the original when the original is not set on the original tray, and which is displaced to a detection position for the original by contact with the original when the original is set on the original tray; and a light emitting section and a light receiving section which are provided on a device body of the original feeder. and an original detection sensor, wherein the original detection lever is provided with a light blocking body that displaces in conjunction with the displacement of the original detection lever to a light blocking position that blocks the light emitted from the light emitting section of the original detection sensor to the light receiving section, or to a light receiving position that can receive the light emitted, and when the light blocking body is in the light blocking position, the original detection sensor is in a light blocking state in which the light emitted is blocked, and when the light blocking body is in the light receiving position, the original detection sensor is in a light receiving state in which the light emitted is received, and the control unit determines that when the original detection sensor is in the light receiving state, the opening / closing cover is open, or that the opening / closing cover is closed and the original is not set in the original tray, and determines that when the original detection sensor is in the light blocking state, the opening / closing cover is closed and the original is set in the original tray.

[0008] According to the above-mentioned configuration, the control unit can determine the state of the document feeder based on the signal from the document detection sensor, so that it is possible to omit a dedicated open / close detection unit for detecting the open / close state of the open / close cover as in the conventional image forming apparatus, and therefore it is possible to provide an image forming apparatus that is advantageous in terms of cost and space.

[0009] The image forming apparatus according to the present disclosure may include a jam detection sensor that detects a jam in the document transported through the document transport path, and an operation unit, and the control unit may further be characterized in that when the operation unit is operated after the jam detection sensor switches from a jam detection state in which it detects a jam in the document to a jam non-detection state in which it does not detect a jam, the control unit switches the image forming apparatus from the jam detection state to a job resume state.

[0010] In the image forming apparatus according to the present disclosure, a display unit may be provided, and the control unit may be configured to switch the image forming apparatus from the jam detection state to the job resume state, and to switch the display of the display unit from a screen representing the jam detection state to a screen representing the job resume state.

[0011] In the image forming apparatus according to the present disclosure, the control unit may be configured to switch the image forming apparatus from the jam detection state to the job resumption state, and further cause the pickup unit to execute an initial operation.

[0012] In order to achieve the above-mentioned object, an image forming apparatus according to the present disclosure is an image forming apparatus including a document feeder having a document tray on which a document is set, a document set detection section which detects that the document has been set on the document tray, and a pickup unit which has a pickup roller which sends the document set on the document tray to a downstream side of a document transport path, and a control section which controls the document feeder, wherein the document set detection section is provided on an opening / closing cover which is provided above the document tray and can be opened and closed, and is in a document detection standby position when the document is not set on the document tray, and is displaced to a detection position for the document by contact with the document when the document is set on the document tray, and a document detection lever which is provided in a device body of the document feeder and has a light emitting section and a light receiving section. and a document detection sensor, wherein the document detection lever is provided with a light blocking body that is displaced in conjunction with the displacement of the document detection lever to a light blocking position where light emission from the light emitting section to the light receiving section of the document detection sensor is blocked or to a light receiving position where the light emission can be received, and when the light blocking body is in the light blocking position, the document detection sensor is in a light blocking state where the light emission is blocked, and when the light blocking body is in the light receiving position, the document detection sensor is in a light receiving state where the light emission is received, and the control unit determines that when the document detection sensor is in the light blocking state, the opening / closing cover is closed and the document is not set on the document tray, and when the document detection sensor is in the light receiving state, the control unit determines that the opening / closing cover is open, or determines that the opening / closing cover is closed and the document is set on the document tray.

[0013] According to the above-mentioned configuration, the control unit can determine the state of the document feeder based on the signal from the document detection sensor, so that it is possible to omit a dedicated open / close detection unit for detecting the open / close state of the open / close cover as in the conventional image forming apparatus, and therefore it is possible to provide an image forming apparatus that is advantageous in terms of cost and space.

[0014] In the image forming apparatus of the present disclosure, a jam detection sensor is provided for detecting a jam in the document transported through the document transport path, and the control unit may further be characterized in that it switches the image forming apparatus from the jam detection state to a job resume state when the jam detection sensor switches from a jam detection state in which it detects a jam in the document to a jam non-detection state in which it does not detect a jam, and when the opening / closing cover is closed and it is determined that the document is not set in the document tray at that time.

[0015] In the image forming apparatus according to the present disclosure, a display unit may be provided, and the control unit may be configured to switch the image forming apparatus from the jam detection state to the job resume state, and to switch the display of the display unit from a screen representing the jam detection state to a screen representing the job resume state.

[0016] In the image forming apparatus according to the present disclosure, the control unit may be configured to switch the image forming apparatus from the jam detection state to the job resumption state, and further cause the pickup unit to execute an initial operation.

[0017] In order to achieve the above-mentioned object, an image forming apparatus according to the present disclosure is an image forming apparatus including a document feeder having a document tray on which a document is set, a document set detection section which detects that the document has been set on the document tray, and a pickup unit which has a pickup roller which sends the document set on the document tray to a downstream side of a document transport path, and a control section which controls the document feeder, the image forming apparatus including a jam detection sensor which detects a jam of the document transported on the document transport path, the document set detection section being provided on an opening / closing cover which is provided above the document tray and which is openable and closable, a document detection lever which is in a detection standby position for the document when the document is not set on the document tray, and which is displaced to a detection position for the document upon contact with the document when the document is set on the document tray, and a document detection sensor which is provided in a device body of the document feeder and has a light emitting section and a light receiving section, and a light emitting section which is connected to the document detection lever and which is connected to the document detection sensor in front of the document detection sensor in response to the displacement of the document detection lever. The image forming apparatus is characterized in that the image forming apparatus is provided with a light-shielding body that is displaced to a light-shielding position where the light emitted from the light-emitting unit to the light-receiving unit is blocked or to a light-receiving position where the light emitted can be received, and when the light-shielding body is in the light-shielding position, the document detection sensor is in a light-shielding state where the light emitted is blocked, and when the light-shielding body is in the light-receiving position, the document detection sensor is in a light-receiving state where the light emitted is received, and the control unit determines that when the document detection sensor is in the light-receiving state, the opening / closing cover is in an open state, or determines that the opening / closing cover is in a closed state and the document is not set in the document tray, and when the document detection sensor is in the light-shielding state, determines that the opening / closing cover is in a closed state and the document is set in the document tray, and when the document detection sensor switches from a jam detection state in which the document jam is detected to a jam non-detection state in which the jam is not detected, when the document detection sensor switches from the light-receiving state via the light-shielding state to the light-receiving state, the image forming apparatus switches from the jam detection state to a job resumption state.

[0018] According to the above-mentioned configuration, the control unit can determine the state of the document feeder based on signals from the document detection sensor and jam detection sensor, so that it is possible to omit a dedicated open / close detection unit for detecting the open / close state of the open / close cover as in conventional image forming devices, thereby providing an image forming device that is advantageous in terms of cost and space.

[0019] In the image forming apparatus according to the present disclosure, a display unit may be provided, and the control unit may switch the image forming apparatus from the jam detection state to the job resume state, and switch the display of the display unit from a screen showing the jam detection state to a screen showing the job resume state.

[0020] In the image forming apparatus according to the present disclosure, the control unit may be configured to switch the image forming apparatus from the jam detection state to the job resumption state, and further cause the pickup unit to execute an initial operation. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing an external appearance of an image forming apparatus. [Diagram 2] 1 is a perspective front view showing a schematic configuration of an image forming apparatus; [Diagram 3] FIG. 2 is an explanatory diagram illustrating an outline of a document feeder. [Figure 4] FIG. 2 is an explanatory diagram illustrating an outline of a document feeder. [Diagram 5] 1A to 1F are explanatory views of the document detection member, in which (a) is a top view, (b) is a left side view, (c) is a front view, (d) is a right side view, (e) is a bottom view, and (f) is a rear view. [Figure 6] FIG. 1 is an explanatory diagram of the detector, where (a) is a top view, (b) is a left side view, (c) is a front view, (d) is a right side view, (e) is a bottom view, and (f) is a rear view. [Figure 7] FIG. 2 is an explanatory diagram illustrating a hardware configuration of an image forming apparatus. [Figure 8] FIG. 2 is an explanatory diagram showing the document feeder with the access cover open; [Figure 9] FIG. 2 is an explanatory diagram showing the document feeder with the opening / closing cover closed; [Figure 10] FIG. 2 is an explanatory diagram showing the document feeder on which a document is set; [Figure 11] 2 is an explanatory diagram showing the document feeder in the image forming apparatus according to the first embodiment with the access cover open; FIG. [Figure 12] 2 is an explanatory diagram showing the document feeder in the image forming apparatus according to the first embodiment with the access cover closed; FIG. [Figure 13] 2 is an explanatory diagram showing the document feeder on which a document is set in the image forming apparatus according to the first embodiment. FIG. [Figure 14] 11 is an explanatory diagram showing a document feeder with the access cover open in an image forming apparatus according to a second embodiment. FIG. [Figure 15] FIG. 11 is an explanatory diagram showing a document feeder in an image forming apparatus according to a second embodiment with the access cover closed. [Figure 16] FIG. 11 is an explanatory diagram showing an original feeder on which an original is set in an image forming apparatus according to a second embodiment. [Figure 17] FIG. 11 is an explanatory diagram showing a document feeder with the access cover open in an image forming apparatus according to a third embodiment. [Figure 18] FIG. 11 is an explanatory diagram showing a document feeder in an image forming apparatus according to a third embodiment with the access cover closed. [Figure 19] FIG. 11 is an explanatory diagram showing an original feeder on which an original is set in an image forming apparatus according to a third embodiment. [Figure 20] 6 is an explanatory diagram of the contents displayed on the display unit when a jam occurs. FIG. [Figure 21] FIG. 11 is an explanatory diagram of the contents displayed on the display unit after a jam is cleared. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] (Embodiment 1) An image forming apparatus 1 according to a first embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view showing the appearance of the image forming apparatus 1 according to the first embodiment of the present disclosure, and FIG. 2 is a front view showing a schematic configuration of the image forming apparatus 1 in a perspective manner. In the coordinates shown in FIGS. 1 and 2, the X-axis direction indicates the left-right direction (horizontal direction) when the image forming apparatus 1 is viewed from the front, and the positive X-axis direction and the negative X-axis direction represent the left side and the right side, respectively. The Y-axis direction indicates the depth direction (front-rear direction) perpendicular to the X-axis, which is the left-right direction, and the positive Y-axis direction and the negative Y-axis direction represent the operation side (front side) and the rear side, which is the opposite side to the operation side, respectively. The Z-axis direction represents the up-down direction, that is, the vertical direction, and the positive Z-axis direction and the negative Z-axis direction represent the upper side and the lower side, respectively. Note that FIGS. 1 and 2 are examples shown to explain the rough configuration of the image forming apparatus 1, and the same image forming apparatus 1 is not illustrated in FIGS. 1 and 2.

[0023] The image forming apparatus 1 is a multifunction machine having a copy function, a scanner function, a facsimile function, and a printer function, and includes an image reading device 102 and an image forming apparatus main body 101. For example, the image forming apparatus 1 can execute a copy job by executing the copy function.

[0024] A copy job will be briefly described below. First, an original is set in the image reading device 102, and a copy operation is instructed on the operation unit 6. The operation unit 6 is provided with a display unit 7, and the user can check the original size, paper size, and copy settings (for example, single-sided, double-sided, 2-in-1 settings, etc.) that have been set on the display unit 7.

[0025] Copy processing is executed when the user performs a copy start operation from the operation unit 6. Specifically, the image reading device 102 reads the document 3 set in the document tray 23, and image data is generated from the document 3 read by the image reading device 102 (see FIG. 10).

[0026] The image forming apparatus main body 101 generates an image based on image data read by the image reading device 102 on paper P fed from a paper cassette 18, and outputs the image from a discharge tray 8. In this embodiment, the paper refers to recording paper on which an image is formed. This includes not only ordinary plain paper, but also various paper media such as cardboard and glossy paper, as well as film and the like on which an image can be formed.

[0027] First, a description will be given of the image forming apparatus main body 101. The image forming apparatus main body 101 includes an image transfer section 50, an optical scanning device 40, an intermediate transfer belt device 70, a secondary transfer device 11, a fixing device 12, a sheet transport path S, a paper cassette 18, and an ejection tray 8.

[0028] The image forming apparatus main body 101 handles image data corresponding to a color image using the colors black (K), cyan (C), magenta (M), and yellow (Y), or a monochrome image using a single color (e.g., black).

[0029] The image transfer section 50 of the image forming apparatus 1 has four image stations Pa, Pb, Pc, Pd corresponding to the colors black, cyan, magenta, and yellow. Each of the image stations Pa, Pb, Pc, Pd includes a developing device 76, a photoconductor drum 77, a drum cleaning device 78, and a charger 79, and four types of toner images are formed by the image stations Pa, Pb, Pc, Pd. That is, in the image forming apparatus 1, four each of the developing devices 76, the photoconductor drums 77, the drum cleaning devices 78, and the chargers 79 are provided, and each corresponds to black, cyan, magenta, and yellow.

[0030] The optical scanning device 40 exposes the surface of the photoconductor drum 77 to light to form an electrostatic latent image. The developing device 76 develops the electrostatic latent image on the surface of the photoconductor drum 77 to form a toner image on the surface of the photoconductor drum 77. The drum cleaning device 78 removes and collects residual toner on the surface of the photoconductor drum 77. The charger 79 uniformly charges the surface of the photoconductor drum 77 to a predetermined potential. Through the series of operations described above, a toner image of each color is formed on the surface of each photoconductor drum 77.

[0031] The intermediate transfer belt device 70 includes an intermediate transfer roller 75, an endless intermediate transfer belt 71, an intermediate transfer driving roller 72, an intermediate transfer driven roller 73, and a cleaning device 74. The intermediate transfer belt 71 is an endless belt that can rotate and is wound around the intermediate transfer driving roller 72 and the intermediate transfer driven roller 73. In other words, the intermediate transfer belt 71 is stretched around the intermediate transfer driving roller 72 and the intermediate transfer driven roller 73. Four intermediate transfer rollers 75 are provided inside the intermediate transfer belt 71 so as to form four types of toner images corresponding to the respective colors. The intermediate transfer rollers 75 transfer the toner images of the respective colors formed on the surfaces of the photosensitive drums 77 to the intermediate transfer belt 71.

[0032] The image forming apparatus 1 sequentially transfers and superimposes the toner images of each color formed on the surface of each photosensitive drum 77, forming a color toner image on the surface of an intermediate transfer belt 71 that is stretched around an intermediate transfer driving roller 72 and an intermediate transfer driven roller 73. The toner images formed on the intermediate transfer belt 71 are transferred to paper P by a secondary transfer device 11. Also, a portion of the toner images formed on the intermediate transfer belt 71 is not transferred to paper P and remains on the surface of the intermediate transfer belt 71 as waste toner, which is removed and collected by a cleaning device 74.

[0033] The secondary transfer device 11 forms a transfer nip area TN between the secondary transfer roller 11a and the intermediate transfer belt 71, and conveys the paper P conveyed through the sheet conveying path S by pinching it in the transfer nip area TN. When the paper P passes through the transfer nip area TN, the toner image on the surface of the intermediate transfer belt 71 is transferred to the paper P, and the paper P is conveyed to the fixing device 12.

[0034] The fixing device 12 includes a fixing roller 31 and a pressure roller 32 that rotate while sandwiching the paper P. The fixing device 12 sandwiches the paper P, on which the toner image has been transferred, between the fixing roller 31 and the pressure roller 32 and applies heat and pressure to fix the toner image to the paper P. Although not shown, a heater serving as a heat source is disposed inside the fixing roller 31, and the heat generated by this heater heats the surface of the fixing roller 31 that comes into contact with the paper P on which the toner image has been transferred.

[0035] The paper cassette 18 is a cassette for storing paper P used for image formation, and is provided below the optical scanning device 40. The paper P is pulled out from the paper cassette 18 by the pickup roller 16 and conveyed to the sheet conveying path S. The paper P conveyed to the sheet conveying path S passes through the secondary transfer device 11 and the fixing device 12, is conveyed to the discharge roller 17, and is discharged to the discharge tray 8 in the discharge section 140. The conveying roller 13, the registration roller 14, and the discharge roller 17 are arranged on the sheet conveying path S. The conveying roller 13 promotes the conveyance of the paper P. The registration roller 14 stops the paper P once and aligns the leading edge of the paper P. Furthermore, the registration roller 14 conveys the stopped paper P in accordance with the timing of the color toner image on the intermediate transfer belt 71. The color toner image on the intermediate transfer belt 71 is transferred to the paper P in the transfer nip area TN between the intermediate transfer belt 71 and the secondary transfer roller 11a.

[0036] In FIG. 2, the number of paper cassettes 18 is one, but the present invention is not limited to this. A configuration may be provided in which multiple paper cassettes 18 are provided, and different types of paper P may be loaded in each of them.

[0037] When forming an image on the back side of the paper P in addition to the front side, the image forming apparatus 1 transports the paper P in the opposite direction from the discharge rollers 17 to the sheet inversion path Sr. The image forming apparatus 1 inverts the paper P transported in the opposite direction and guides it again to the registration rollers 14. The image forming apparatus 1 also forms an image on the back side of the paper P guided to the registration rollers 14 in the same manner as on the front side, and then transports the paper P to the discharge tray 8.

[0038] As shown in FIG. 7, the image forming device 1 has a control unit 5, a storage 110, a ROM 120 and a RAM 130 as memory devices, an operation unit 6 (see FIG. 1), a display unit 7 (see FIG. 1), an image forming unit 160, a document reading unit 21, and a communication unit 170.

[0039] The control unit 5 controls the entire image forming apparatus 1. The control unit 5 realizes various functions by reading and executing various programs stored in one or more storage devices (for example, the storage 110 and the ROM 120). The control unit 5 may be realized by one or more control devices / arithmetic units (CPUs (Central Processing Units)) or SoCs (System on a Chip). The control unit 5 may also be configured by a control circuit.

[0040] Storage 110 is a non-volatile storage device capable of storing programs and data. For example, storage 110 may be configured as a storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Storage 110 may also be configured as a USB memory that can be connected to the outside. Storage 110 may also be a storage area on a cloud, for example.

[0041] The ROM 120 is a non-volatile memory that can retain programs and data even when the power is turned off.

[0042] The RAM 130 is a main memory that is mainly used when the control unit 5 executes processes. The RAM 130 is a rewritable memory that temporarily stores programs read from the storage 110 or the ROM 120, and data including results of execution.

[0043] The operation unit 6 is an operation device that allows a user to input operations. For example, it may be an operation device such as a touch panel integrated with the display unit 7 or an operation button. The operation unit 6 may also be an operation device such as a keyboard or a mouse. The operation unit 6 may also include an interface (for example, a Universal Serial Bus (USB)) to which an operation device can be connected. For example, the image forming apparatus 1 may be connected to a different operation device (an operation device having a touch panel).

[0044] The display unit 7 is a display device capable of displaying various information and an execution screen. The display unit 7 may be, for example, a display device such as a liquid crystal display (LCD), an organic electroluminescence (EL) display, or an electrophoretic display. The display unit 7 also includes an interface to which a display device can be connected. For example, the display unit 7 may be configured with an external display device connected via an HDMI (registered trademark) (High-Definition Multimedia Interface), a DVI (Digital Visual Interface), or a Display Port. The display unit 7 may be of any size. For example, in recent years, a large operation panel such as an 8-inch or 10-inch panel is often used as the display unit 7 in order to improve operability.

[0045] As will be described later, the document reading unit 21 reads an image of the document 3 and outputs it as image data. The document reading unit 21 is, for example, a scanner, and may be a reading device that uses a CCD (Charge Coupled Device) or a CIS (Contact Image Sensor).

[0046] The communication unit 170 is a communication interface for communicating with other devices. For example, it may be a network interface capable of providing a wired connection or a wireless connection. In this embodiment, communication with other devices is possible via a network NW.

[0047] Next, the image reading device 102 will be described. As shown in FIG. 2, FIG. 3, and FIG. 4, the image reading device 102 includes a document reading unit 21 and a document feeder 2 [automatic document feeder (ADF)]. The document feeder 2 is provided above the document reading unit 21 and is supported so as to be freely opened and closed relative to the document reading unit 21. In addition, in the coordinates shown in FIG. 3 and FIG. 4, the X-axis direction indicates the left-right direction (horizontal direction) when the document feeder 2 is viewed from the front, and the positive X-axis direction and the negative X-axis direction respectively indicate the left side and the right side. The document feeder 2 transports the document along the X-axis direction. That is, the X-axis direction is a direction along the document transport direction. The Y-axis direction indicates a depth direction (front-rear direction) perpendicular to the X-axis, which is the left-right direction, and the positive Y-axis direction and the negative Y-axis direction respectively indicate the operation side (front side) and the rear side, which is the opposite side to the operation side. The Y-axis direction is a direction perpendicular to the document transport direction. The Z-axis direction represents the up-down direction, that is, the vertical direction, and the positive Z-axis direction and the negative Z-axis direction represent the upper side and the lower side, respectively.

[0048] The document feeder 2 sequentially conveys one or more documents 3 one by one. The image reader 102 reads the documents 3 conveyed by the document feeder 2 one by one out of the one or more documents 3.

[0049] The document reading section 21 includes a document placement table 22 on which the document 3 is placed, and a scanning optical system 131 including a first document reading section 21 a.

[0050] The image reading device 102 has a document reading function for reading the document 3 placed on the document placement table 22. When the document feeder 2 is opened, the document placement table 22 (see, for example, Figs. 8 to 19) above the document reading unit 21 is exposed, and the document 3 can be placed manually on the document placement table 22. The document reading unit 21 scans the scanning optical system 131 to read the document placed on the document placement table 22. In the coordinates shown in Figs. 8 to 19, the X-axis direction indicates the left-right direction (horizontal direction) when the document feeder 2 is viewed from the front, and the positive X-axis direction and the negative X-axis direction respectively indicate the left side and the right side. The document feeder 2 transports the document along the X-axis direction. In other words, the X-axis direction is a direction along the document transport direction. The Y-axis direction indicates the depth direction (front-back direction) perpendicular to the X-axis, which is the left-right direction, and the positive and negative Y-axis directions respectively represent the operation side (front side) and the rear side, which is the opposite side of the operation side. The Y-axis direction is perpendicular to the document transport direction. The Z-axis direction represents the up-down direction, or vertical direction, and the positive and negative Z-axis directions represent the upper and lower sides, respectively.

[0051] The document feeder 2 also includes a document tray 23 on which the documents 3 are stacked, and a pickup unit 26 that pulls out the documents 3 stacked on the document tray 23 one by one. The pickup unit 26 includes a pickup roller 26a and a feed roller 26b that transports the documents 3 pulled out by the pickup roller 26a, which are provided in a roller holder 26c.

[0052] The document feeding device 2 further includes a large diameter conveying roller 29 that conveys the document 3 conveyed by the feed roller 26b, a driven roller 33 arranged to face the large diameter conveying roller 29 and be in pressure contact with it, a second document reading unit 21b that reads the back side (other side) of the document 3 being conveyed, and a pair of document discharge rollers 34 for discharging the read document 3 to the document discharge tray 28.

[0053] The document feeder 2 has a document transport path 27 along which the document 3 is transported, and a part of the document transport path 27 is curved in a U-shape. The document transport path 27 has a first document reading position A1 where the front side (one side) of the document 3 is read by the first document reading unit 21a, and a second document reading position A2 where the back side of the document 3 is read by the second document reading unit 21b.

[0054] The document reading unit 21 (see FIG. 2) is composed of a light source of three RGB color LEDs whose blinking is controlled by the control unit 5, and a so-called CIS type scanner that shines the light emitted from the light source onto the document 3 through the document placement table 22 and reads the light reflected from the document 3 with an image sensor via a lens array. However, the document reading unit 21 may be composed of a CDD type scanner.

[0055] As shown in Figures 8 to 10, the document feeder 2 is equipped with a document tray 23 on which the document 3 is set, an opening / closing cover 24 that is arranged to be openable and closable above the document tray 23, a document set detection section 25 that detects that the document 3 has been set in the document tray 23, a pickup unit 26 that sends the document 3 set in the document tray 23 to a document reading section 21 that reads the contents of the document 3, a detection body 27A that moves in response to the document 3 transported through a document transport path 27 inside the document feeder 2, a jam detection sensor 27B that detects a jam of the document 3 based on the movement of the detection body 27A, and a document discharge tray 28 to discharge the read document 3.

[0056] A jam refers to an interruption of operation due to a blockage of the document 3 in the document transport path 27. When a jam occurs, normal reading of the document 3 cannot continue, so it is necessary to open the opening / closing cover 24 and remove the jammed document 3.

[0057] As shown in Figures 9 to 11, the document set detection unit 25 includes a document detection member 25A rotatably provided on the underside of the opening / closing cover 24, and a document detection sensor 25B provided in the document feeding device main body 2a of the document feeding device 2.

[0058] As shown in Figures 5(a), 5(b), 5(c), 5(d), 5(e), and 5(f), the document detection member 25A includes a document detection lever 25a, a light shielding body 25b, and a rotating shaft 25c connecting the document detection lever and the light shielding body, which are integrally formed. The document detection member 25A is supported so as to be rotatable about the rotating shaft 25c, as shown in Figures 11, 12, and 13.

[0059] 3 and 4, the document detection member 25A is disposed along the Y-axis direction (a direction perpendicular to the document transport direction). The document detection lever 25a is disposed within the document width region and in the body of the document feeder 2 so as to contact the document 3. On the other hand, the light shielding body 25d and the document detection sensor 25B are disposed outside the document width region and in the body of the document feeder 2 so as not to contact the document 3.

[0060] When the opening / closing cover 24 is opened, the document detection member 25A rotates due to its own weight, and the document detection lever 25a and the light blocking body 25d are positioned as shown in Fig. 11. On the other hand, when the opening / closing cover 24 is closed, the document detection member 25A rotates due to its own weight, and the document detection lever 25a and the light blocking body 25d are positioned as shown in Fig. 12.

[0061] When the document 3 is set on the document tray 23, the document detection member 25A rotates due to contact with the document 3, and the document detection lever 25a and the light blocking body 25d are positioned as shown in FIG.

[0062] The document detection sensor 25B is composed of a transmission type photoelectric sensor having a light emitting portion that emits light in a straight line and a light receiving portion that receives the light emitted from the light emitting portion.

[0063] Depending on the presence or absence of a light-shielding body 25d between the light-emitting unit and the light-receiving unit, the emitted light is blocked or received, and when the amount of light received by the light-receiving unit changes, the electrical characteristics of the photoelectric conversion element built into the light-receiving unit change, and this is detected, amplified, and an object detection signal is output to the control unit 5.

[0064] Depending on whether or not a document 3 is set, i.e., in conjunction with the displacement of the document detection lever 25a, the light shielding body 25d is displaced to a light shielding position where the light emitted from the light emitting portion of the document detection sensor 25B to the light receiving portion is blocked, or to a light receiving position where the light emitted is received without being blocked.

[0065] In this embodiment, when the opening / closing cover 24 is closed, the light shielding body 25d is in the light receiving position (see Figure 12) when the document detection lever 25a is in the detection standby position, and the light shielding body 25d is in the light shielding position (see Figure 13) when the document detection lever 25a is in the detection position.

[0066] Therefore, when the light blocking body 25d is in the light receiving position, the document detection sensor 25B is in a light receiving state where emitted light is received, and when the light blocking body 25d is in the light blocking position, the document detection sensor 25B is in a light blocking state where emitted light is blocked.

[0067] In other words, when no document 3 is set, document detection lever 25a is located at the detection standby position (see FIG. 12) because there is no document 3 in contact with document detection lever 25a. At this time, light shielding body 25d is located at a light receiving position where light emitted from the light emitting portion can be received by the light receiving portion in document detection sensor 25B, so document detection sensor 25B is in a light receiving state.

[0068] When the document 3 is set, the document detection lever 25a is in contact with the document 3 and is located at the detection position (see FIG. 13). At this time, the light blocking body 25d is in a light blocking position where it blocks light emitted from the light emitting portion to the light receiving portion in the document detection sensor 25B, so that the document detection sensor 25B is in a light blocking state.

[0069] 3, 4, and 8 to 10, pickup unit 26 has pickup roller 26a that picks up the top document 3 among documents 3 set on document tray 23, feed roller 26b that sends the picked up document 3 along document transport path 27 to document reading section 21, and roller holder 26c that holds these. Pickup unit 26 is driven by power transmitted from document feeder main body 2a via power transmission mechanism 26d.

[0070] During standby, the pickup roller 26a is in a standby position (see solid line in Figure 9) spaced a predetermined distance from the document tray 23, but when the document detection lever 25a detects that a document 3 has been set in the document tray 23 and document reading is instructed on the operation unit 6, the pickup roller 26a is controlled to move down from the standby position to a contact position (see Figure 10) where it comes into contact with the top surface of the document 3.

[0071] The control unit 5 causes the pickup unit 26 to perform an initial operation at a predetermined timing, which will be described later. The initial operation refers to an operation of moving the pickup unit 26 from a position close to the document tray 23 (see the two-dot chain line in FIG. 9) to a position at a predetermined distance from the document tray 23 (see the solid line in FIG. 9). This prevents problems such as, for example, when setting a document on the document tray 23, making it difficult to set the document 3 because the pickup roller 26a of the pickup unit 26 is in the contact position.

[0072] As shown in Figures 6(a), 6(b), 6(c), 6(d), 6(e), and 6(f), the detection body 27A is composed of a detection piece 27a and a light blocking body 27b, which are integrally formed. The detection body 27A is supported so as to rotate around a detection body rotation shaft 27c.

[0073] The detector 27A is configured to detect the document 3 by coming into contact with the document 3 being transported, and is therefore provided within the width region of the document 3 in a direction perpendicular to the transport direction of the document 3.

[0074] When the leading edge of the document 3 being transported along the document transport path 27 comes into contact with the detection piece 27a, the detection body 27A rotates counterclockwise around the detection body pivot axis 27c in Figures 10 and 13, and when the trailing edge of the document 3 no longer comes into contact with the detection piece 27a, the detection body 27A rotates to its original position due to its own weight and stops.

[0075] The jam detection sensor 27B is also composed of a transmission type photoelectric sensor equipped with a light emitting portion and a light receiving portion. The detector 27A moves in conjunction with the conveyed document 3 to a light blocking position where the light emitted from the light emitting portion of the jam detection sensor 27B to the light receiving portion is blocked, or to a light receiving position where the light emitted is received without being blocked.

[0076] That is, the detector 27A is configured to be in the light receiving position while the document 3 is in contact with the detector 27A, and in the light blocking position when the document 3 is not in contact with the detector 27A. Therefore, the jam detection sensor 27B is in a light receiving state where emitted light is received when the detector 27A is in the light receiving position, and in a light blocking state where emitted light is blocked when the detector 27A is in the light blocking position.

[0077] In this manner, the rotation of the detector 27A causes the light blocking body 27b to rotate, thereby turning the jam detection sensor 27B ON / OFF (light blocking / light transmitting). When the document 3 is not in contact with the detector piece 27a, the light blocking body 27b of the detector 27A is in a position blocking the jam detection sensor 27B as shown in Figs. 10 and 13, and when the document 3 comes in contact with the detector piece 27a of the detector 27A, the detector 27A rotates counterclockwise and the light blocking body 27b is in a position that allows the jam detection sensor 27B to receive light.

[0078] During a normal document reading job, the document 3 is transported at a predetermined transport speed, so the jam detection sensor 27B is in a light-blocking state until the document 3 is transported, but it is in a light-receiving state for a predetermined time while the document 3 is being transported, and is in a light-blocking state when the document 3 has passed by. When the document 3 is being transported smoothly, a jam is not detected (not detected). On the other hand, when a jam occurs, the document continues to stay in the document transport path 27 without passing through, so the jam detection sensor 27B continues to be in a light-receiving state. At such a time, the control unit 5 detects that a jam has occurred.

[0079] The control unit 5 is configured to cause the document feeder 2 configured as described above to execute various types of judgments and various types of processing. The control of the control unit 5 in this embodiment will be described with reference to Table 1 below.

[0080] [Table 1]

[0081] When the image forming device 1 is in standby (the jam detection sensor 27B has not detected a jam of the document 3 and the image forming device 1 is in a state in which the operation to execute a reading job can be accepted), if the document detection sensor 25B of the document set detection unit 25 is in a light receiving state in which the light emitted from the light emitting unit can be received by the light receiving unit, the control unit 5 determines that the opening / closing cover 24 is in an open state as shown in FIG. 11, or that the opening / closing cover 24 is in a closed state as shown in FIG. 12 and no document 3 is set in the document tray 23.

[0082] When the image forming device 1 is on standby, if the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state in which light emission from the light-emitting unit to the light-receiving unit is blocked, the control unit 5 determines that the opening / closing cover 24 is closed as shown in FIG. 13 and that a document 3 is set in the document tray 23.

[0083] When the image forming apparatus 1 is executing a reading job of the document 3, if the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state, the control unit 5 continues the reading job because the document 3 still remains in the document tray 23. Note that the jam detection sensor 27B alternates between a light-blocking state and a light-receiving state every time the document 3 passes through the document transport path 27. In such a case, the control unit 5 does not detect a jam.

[0084] When the image forming apparatus 1 is executing a reading job of the original 3, if the original detection sensor 25B of the original set detection unit 25 is in a light receiving state (switches from a light blocking state to a light receiving state), the control unit 5 ends the reading job because there are no originals 3 in the original tray 23. Note that the jam detection sensor 27B goes from a state in which it alternates between a light blocking state and a light receiving state every time a original 3 passes through the original transport path 27 to a light receiving state after the last sheet of original 3 has passed through. In such a case, the control unit 5 does not detect a jam.

[0085] On the other hand, when the image forming device 1 is executing a reading job of the original 3, if the jam detection sensor 27B remains in a light receiving state for a predetermined time (jam detection), the control unit 5 determines that a jam has occurred, since it is believed that the original 3 is not being transported properly and is remaining in the original transport path 27.

[0086] When the control unit 5 determines that a jam has occurred, it stops the reading job and notifies the user that a jam has occurred. The notification is performed, for example, by displaying a screen showing the jam detection state on the display unit 7 as shown in Fig. 20. At that time, an instruction to remove the document 3 from the document tray 23 may be given at the same time. The notification may also be performed by blinking a separately provided lamp, etc.

[0087] When the control unit 5 determines that a jam has occurred, it is predicted that the document 3 will be removed from the document tray 23 and the opening / closing cover 24 will be opened to clear the jam, as shown in FIG. 11. Therefore, the light receiving state of the document detection sensor 25B at this time may be determined to be that the opening / closing cover 24 is open.

[0088] When the jam detection sensor 27B becomes light-blocking (non-jam detection state) after notifying the control unit 5 that a jam has occurred, the control unit 5 determines that the document 3 in the document transport path 27 has been removed and the jam has been cleared, and prompts the user on the display unit 7 to confirm that the jam has been cleared.

[0089] When the user operates the display unit 7 (presses the OK button shown in FIG. 20), the control unit 5 causes the pickup unit 26 to execute an initial operation and causes the display unit 7 to display a screen indicating the job resume status, as shown in FIG. 21.

[0090] When the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state (switches from a light-receiving state to a light-blocking state), the control unit 5 determines that the opening / closing cover 24 is closed as shown in FIG. 13 and that a document 3 is set in the document tray 23, and enters a state in which it can accept an operation to execute a reading job for the document 3 (job resumed state).

[0091] That is, the image forming apparatus 1 is provided with a jam detection sensor 27B that detects a jam in the document 3 being transported through the document transport path 27, and an operation unit 6, and the control unit 5 further switches the image forming apparatus 1 from the jam detection state to the job resume state when the operation unit 6 is operated after the jam detection sensor 27B switches from a jam detection state in which it detects a jam in the document 3 to a jam non-detection state in which it does not detect a jam.

[0092] As described above, the control unit 5 can determine the state of the document feeder 2 based on signals from the document detection sensor 25B and the jam detection sensor 27B and control the document feeder 2, so that it is possible to omit a dedicated open / close detection means for detecting the open / close state of the open / close cover 24 as in conventional image forming devices. Therefore, it has become possible to provide an image forming device 1 that is advantageous in terms of cost and space.

[0093] (Embodiment 2) Next, a second embodiment of the present disclosure will be described with reference to the accompanying drawings, particularly Figures 14, 15, and 16. Here, configurations different from those of the first embodiment described above will be described, and the above description will be used to refer to similar configurations.

[0094] Like the document detection member 25A in embodiment 1, the document detection member 25A in embodiment 2 also comprises a document detection lever 25a, a light shield 25b, and a pivot shaft 25c connecting the document detection lever 25a and the light shield 25b, and these are similar in that they are formed integrally. However, it differs from the document detection member 25A in embodiment 1 in the attachment angle of the light shield 25b relative to the pivot shaft 25c.

[0095] The second embodiment is different from the first embodiment in the control of the control unit 5 based on the document detection sensor 25B whose light receiving state or light blocking state is changed by the light blocking body 25d.

[0096] In this embodiment, when the opening / closing cover 24 is closed, the light shielding body 25d is in the light shielding position (see Figure 15) when the document detection lever 25a is in the detection standby position, and the light shielding body 25d is in the light receiving position (see Figure 16) when the document detection lever 25a is in the detection position.

[0097] Therefore, when the light blocking body 25d is in the light blocking position, the document detection sensor 25B is in a light blocking state where light emission is blocked, and when the light blocking body 25d is in the light receiving position, the document detection sensor 25B is in a light receiving state where light emission is received.

[0098] In other words, when no document 3 is set, document detection lever 25a is located at the detection standby position (see FIG. 15) because there is no document 3 in contact with document detection lever 25a. At this time, light blocking body 25d is at a light blocking position where light is blocked from being emitted from the light emitting portion to the light receiving portion in document detection sensor 25B, so document detection sensor 25B is in a light blocking state.

[0099] When the document 3 is set, the document detection lever 25a is in contact with the document 3 and is located at the detection position (see FIG. 16). At this time, the light shielding body 25d is in a light receiving position where the light receiving portion of the document detection sensor 25B can receive light emitted from the light emitting portion, so the document detection sensor 25B is in a light receiving state.

[0100] The control unit 5 is configured to cause the document feeder 2 configured as described above to execute various determinations and various processes. The control of the control unit 5 in this embodiment will be described with reference to Table 2 below.

[0101] [Table 2]

[0102] When the image forming device 1 is in standby (the jam detection sensor 27B has not detected a jam in the document 3 and the image forming device 1 is in a state in which it can accept an operation to execute a reading job), if the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state, the control unit 5 determines that the opening / closing cover 24 is closed as shown in FIG. 15 and that the document 3 is not set in the document tray 23.

[0103] When the image forming device 1 is on standby and the document detection sensor 25B of the document set detection unit 25 is in a light receiving state, the control unit 5 determines that the opening / closing cover 24 is open as shown in FIG. 14, or determines that the opening / closing cover 24 is closed and a document 3 is set in the document tray 23 as shown in FIG. 16.

[0104] When the image forming apparatus 1 is executing a reading job of the document 3, if the document detection sensor 25B of the document set detection unit 25 is in a light receiving state, the control unit 5 continues the reading job because the document 3 still remains in the document tray 23. Note that the jam detection sensor 27B alternates between a light blocking state and a light receiving state every time the document 3 passes through the document transport path. In such a case, the control unit 5 does not detect a jam.

[0105] When the image forming apparatus 1 is executing a reading job of the original 3, if the original detection sensor 25B of the original set detection unit 25 is in a light-blocking state (switches from a light-receiving state to a light-blocking state), the control unit 5 ends the reading job because there are no originals 3 in the original tray 23. Note that the jam detection sensor 27B goes from a state in which it alternates between a light-blocking state and a light-receiving state every time a original 3 passes through the original transport path to a light-blocking state after the last original 3 has passed through. In such a case, the control unit 5 does not detect a jam.

[0106] On the other hand, when the image forming device 1 is executing a reading job of the original 3, if the jam detection sensor 27B remains in a light receiving state for a predetermined time (jam detection), the control unit 5 determines that a jam has occurred, since it is believed that the original 3 is not being transported properly and is remaining in the original transport path.

[0107] When the control unit 5 determines that a jam has occurred, it stops the reading job and notifies the user that a jam has occurred. The notification is performed, for example, by displaying a screen showing the jam detection state on the display unit 7 as shown in Fig. 20. At that time, an instruction to remove the document 3 from the document tray 23 may be given at the same time. The notification may also be performed by blinking a separately provided lamp, etc.

[0108] When the control unit 5 determines that a jam has occurred, it predicts that the opening / closing cover 24 will be opened, the document 3 will be removed from the document tray 23, and the jam will be cleared, as shown in FIG. 14. Therefore, the light receiving state of the document detection sensor 25B at this time may be determined to be that the opening / closing cover 24 is open.

[0109] When the jam detection sensor 27B becomes a light-blocking state (jam non-detecting state) after notifying the occurrence of a jam, the control unit 5 determines that the document 3 in the document transport path 27 has been removed and the jam has been cleared, or when the document detection sensor 25B becomes a light-blocking state from a light-receiving state, the control unit 5 determines that the document 3 in the document transport path has been removed and the jam has been cleared and the opening / closing cover 24 has been closed, and notifies the user on the display unit 7 that the jam has been cleared. At this time, the document 3 is not set in the document tray 23.

[0110] When the user operates the display unit 7 (presses the OK button shown in FIG. 20), the control unit 5 causes the pickup unit 26 to execute an initial operation and causes the display unit 7 to display a screen indicating the job resume status, as shown in FIG. 21.

[0111] Thereafter, when the document detection sensor 25B of the document set detection unit 25 is in a light receiving state (switches from a light blocking state to a light receiving state), the control unit 5 determines that the opening / closing cover 24 is closed as shown in FIG. 16 and that a document 3 is set in the document tray 23, and enters a state in which it can accept an operation to execute a reading job for the document 3 (job resumed state).

[0112] That is, the image forming apparatus 1 is provided with a jam detection sensor 27B that detects a jam of the document 3 transported through the document transport path 27, and the control unit 5 further switches the image forming apparatus 1 from the jam detection state to the job resume state on the condition that the jam detection sensor 27B switches from a jam detection state in which it detects a jam of the document 3 to a jam non-detection state in which it does not detect a jam, and that the opening / closing cover 24 is closed and it is determined that no document 3 is set in the document tray 23 at that time. The image forming apparatus 1 is further provided with a display unit 7, and the control unit 5 switches the image forming apparatus 1 from the jam detection state to the job resume state, and switches the display on the display unit 7 from a screen showing the jam detection state (see FIG. 20) to a screen showing the job resume state (see FIG. 21).

[0113] As described above, the control unit 5 can determine the state of the document feeder 2 based on signals from the document detection sensor 25B and the jam detection sensor 27B and control the document feeder 2, so that it is possible to omit a dedicated open / close detection means for detecting the open / close state of the open / close cover 24 as in conventional image forming devices. Therefore, it has become possible to provide an image forming device 1 that is advantageous in terms of cost and space.

[0114] (Embodiment 3) Next, a third embodiment of the present disclosure will be described with reference to the accompanying drawings, particularly Figures 17, 18, and 19. Here, configurations different from those of the first and second embodiments described above will be described, and the above descriptions will be used to refer to similar configurations.

[0115] Like the document detection member 25A in embodiment 1, the document detection member 25A in embodiment 3 is equipped with a document detection lever 25a, a light shield 25b, and a pivot shaft 25c connecting the document detection lever 25a and the light shield 25b, which are all formed as a single unit. However, it differs from embodiment 1 in the attachment angle of the light shield 25b relative to the pivot shaft 25c and in that the light shield 25b is provided with an opening 25e through which light can pass from the light-emitting section.

[0116] The third embodiment is different from the first and second embodiments in the control of the control unit 5 based on the document detection sensor 25B whose light receiving state or light blocking state is changed by the light blocking body 25d.

[0117] In this embodiment, when the opening / closing cover 24 is closed and the document detection lever 25a is in the detection standby position, the light shielding body 25d is in a light receiving position (see Figure 18) where the light emitted from the light emitting unit can be received by the light receiving unit through the opening 25e, and when the document detection lever 25a is in the detection position, the light shielding body 25d is in a light shielding position (see Figure 19).

[0118] Therefore, when the light blocking body 25d is in the light receiving position, the document detection sensor 25B is in a light receiving state where emitted light is received, and when the light blocking body 25d is in the light blocking position, the document detection sensor 25B is in a light blocking state where emitted light is blocked.

[0119] In other words, when no document 3 is set, document detection lever 25a is located at the detection standby position (see FIG. 18) because there is no document 3 in contact with document detection lever 25a. At this time, light shielding body 25d is located at a light receiving position where light emitted from the light emitting portion can be received by the light receiving portion in document detection sensor 25B, so document detection sensor 25B is in a light receiving state.

[0120] When the document 3 is set, the document detection lever 25a is in contact with the document 3 and is located at the detection position (see FIG. 19). At this time, the light blocking body 25d is in a light blocking position where it blocks light emitted from the light emitting portion to the light receiving portion in the document detection sensor 25B, so that the document detection sensor 25B is in a light blocking state.

[0121] The control unit 5 is configured to cause the document feeder 2 configured as described above to execute various determinations and various processes. The control of the control unit 5 in this embodiment will be described with reference to Table 3 below.

[0122] [Table 3]

[0123] When the image forming device 1 is in standby (the jam detection sensor 27B has not detected a jam in the document 3 and the operation to execute a reading job can be accepted), if the document detection sensor 25B of the document set detection unit 25 is in a light receiving state, the control unit 5 determines that the opening / closing cover 24 is open as shown in FIG. 17, or that the opening / closing cover 24 is closed and no document 3 is set in the document tray 23 as shown in FIG. 18.

[0124] When the image forming device 1 is on standby and the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state, the control unit 5 determines that the opening / closing cover 24 is closed and a document 3 is set in the document tray 23, as shown in FIG. 19.

[0125] When the image forming apparatus 1 is on standby and the document detection sensor 25B of the document set detection unit 25 switches from a light-blocking state to a light-receiving state, the control unit 5 determines that the opening / closing cover 24 is open as shown in FIG. 17, or that the opening / closing cover 24 is closed as shown in FIG. 18 and no document 3 is set in the document tray 23, and causes the pickup unit 26 to perform an initial operation.

[0126] When the image forming apparatus 1 is executing a reading job of the document 3, if the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state, the control unit 5 continues the reading job because the document 3 still remains in the document tray 23. Note that the jam detection sensor 27B alternates between a light-blocking state and a light-receiving state every time the document 3 passes through the document transport path. In such a case, the control unit 5 does not detect a jam.

[0127] When the image forming apparatus 1 is executing a reading job of the original 3, if the original detection sensor 25B of the original set detection unit 25 is in a light receiving state (switches from a light blocking state to a light receiving state), the control unit 5 ends the reading job because there are no originals 3 in the original tray 23. Note that the jam detection sensor 27B goes from a state in which it alternates between a light blocking state and a light receiving state every time a original 3 passes through the original transport path to a light receiving state after the last sheet of original 3 has passed. In such a case, the control unit 5 does not detect a jam.

[0128] On the other hand, when the image forming device 1 is executing a reading job of the original 3, if the jam detection sensor 27B remains in a light receiving state for a predetermined time (jam detection), the control unit 5 determines that a jam has occurred, since it is believed that the original 3 is not being transported properly and is remaining in the original transport path 27.

[0129] When the control unit 5 determines that a jam has occurred, it stops the reading job and notifies the user that a jam has occurred. The notification is performed, for example, by displaying a screen showing the jam detection state on the display unit 7 as shown in Fig. 20. At that time, an instruction to remove the document 3 from the document tray 23 may be given at the same time. The notification may also be performed by blinking a separately provided lamp, etc.

[0130] When the control unit 5 determines that a jam has occurred, it is predicted that the document 3 will be removed from the document tray 23 and the opening / closing cover 24 will be opened to clear the jam, as shown in FIG. 17. Therefore, the light receiving state of the document detection sensor 25B at this time may be determined to be that the opening / closing cover 24 is open.

[0131] After notifying the control unit 5 that a jam has occurred, if the jam detection sensor 27B becomes a light-blocking state (jam non-detecting state), the control unit 5 determines that the document 3 in the document transport path has been removed and the jam has been cleared, or if the document detection sensor 25B changes from a light-receiving state to a light-blocking state and then to a light-receiving state, the control unit 5 determines that the document 3 in the document transport path has been removed and the jam has been cleared, therefore the opening / closing cover 24 is closed and no document 3 is set, and prompts the user on the display unit 7 to confirm that the jam has been cleared.

[0132] When the user operates the display unit 7 (presses the OK button shown in FIG. 20), the control unit 5 causes the pickup unit 26 to execute an initial operation and causes the display unit 7 to display a screen indicating the job resume status, as shown in FIG. 21.

[0133] Thereafter, when the document detection sensor 25B of the document set detection unit 25 is in a light-blocking state (switches from a light-receiving state to a light-blocking state), the control unit 5 determines that the opening / closing cover 24 is closed as shown in FIG. 19 and that a document 3 is set in the document tray 23, and enters a state in which it can accept an operation to execute a reading job for the document 3 (job resumed state).

[0134] That is, after the jam detection sensor 27B switches from a jam detection state in which it detects a jam of the document 3 to a jam non-detection state in which it does not detect a jam, when the document detection sensor 25B switches from a light receiving state to a light blocking state to a light receiving state, the image forming apparatus 1 is switched from the jam detection state to the job resumption state. Furthermore, the image forming apparatus 1 is provided with a display unit 7, and the control unit 5 switches the image forming apparatus 1 from the jam detection state to the job resumption state, and switches the display of the display unit 7 from a screen showing the jam detection state (see FIG. 20) to a screen showing the job resumption state (see FIG. 21).

[0135] As described above, the control unit 5 can determine the state of the document feeder 2 based on signals from the document detection sensor 25B and the jam detection sensor 27B and control the document feeder 2, so that it is possible to omit a dedicated open / close detection means for detecting the open / close state of the open / close cover 24 as in conventional image forming devices. Therefore, it has become possible to provide an image forming device 1 that is advantageous in terms of cost and space.

[0136] The configurations disclosed in any of the above-described embodiments may be applied in combination with configurations disclosed in other embodiments, provided that no inconsistencies arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the embodiments of the present disclosure are not limited thereto, and may be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0137] 1: Image forming device 2: Document feeder 3: Manuscript 4: Image forming section 5: Control section 6 :Operation section 7: Display section 8: Output tray 21: Document reading section 22: Manuscript stand 23: Document tray 24: Opening and closing cover 25: Document set detector 25A: Document detection member 25B: Document detection sensor 25a: Document detection lever 25b: Light shielding body 25c: Rotating shaft 25d: Light shielding body 25e: opening 26: Pickup unit 26a: Pickup roller 26b: Feed roller 26c: Roller holder 27: Document transport path 27A: Detector 27B: Jam detection sensor 27a: Detection piece 27b: Light shielding body 27c: Rotating axis of the detector 101: Image forming apparatus body 102: Image reader

Claims

1. An image forming apparatus including: a document feeder having a document tray on which a document is set, a document set detection section for detecting that the document has been set on the document tray, and a pickup unit having a pickup roller for sending the document set on the document tray to a downstream side of a document transport path; and a control section for controlling the document feeder, The document set detection unit an original detection lever that is provided on an open / close cover that is openably provided above the original tray, the original detection lever being in a detection standby position for the original when the original is not set on the original tray, and being displaced to a detection position for the original by contact with the original when the original is set on the original tray; a document detection sensor provided in a device body of the document feeder, the document detection sensor having a light emitting section and a light receiving section; the document detection lever is provided with a light blocking body that is displaced in conjunction with a displacement of the document detection lever to a light blocking position where light emission from the light emitting portion to the light receiving portion of the document detection sensor is blocked or to a light receiving position where the light emission can be received, the document detection sensor is in a light blocking state in which the emitted light is blocked when the light blocking body is in the light blocking position, and in a light receiving state in which the emitted light is received when the light blocking body is in the light receiving position, The control unit of the image forming apparatus is characterized in that when the document detection sensor is in the light receiving state, it determines that the opening / closing cover is open, or that the opening / closing cover is closed and the document is not set in the document tray, and when the document detection sensor is in the light blocking state, it determines that the opening / closing cover is closed and the document is set in the document tray.

2. a jam detection sensor that detects a jam of the document transported through the document transport path, and an operation unit; The image forming apparatus according to claim 1, characterized in that when the operation unit is operated after the jam detection sensor has switched from a jam detection state in which the jam detection sensor detects a jam in the document to a jam non-detection state in which the jam is not detected, the control unit switches the image forming apparatus from the jam detection state to a job resume state.

3. A display unit is provided, 3. The image forming apparatus according to claim 2, wherein the control unit switches the image forming apparatus from the jam detection state to the job restart state, and switches the display of the display unit from a screen showing the jam detection state to a screen showing the job restart state.

4. 4. The image forming apparatus according to claim 2, wherein the control unit switches the image forming apparatus from the jam detection state to the job restart state, and further causes the pickup unit to execute an initial operation.

5. An image forming apparatus including: a document feeder having a document tray on which a document is set, a document set detection section for detecting that the document has been set on the document tray, and a pickup unit having a pickup roller for sending the document set on the document tray to a downstream side of a document transport path; and a control section for controlling the document feeder, The document set detection unit an original detection lever that is provided on an open / close cover that is openably provided above the original tray, the original detection lever being in a detection standby position for the original when the original is not set on the original tray, and being displaced to a detection position for the original by contact with the original when the original is set on the original tray; a document detection sensor provided in a device body of the document feeder, the document detection sensor having a light emitting section and a light receiving section; the document detection lever is provided with a light blocking body that is displaced in conjunction with a displacement of the document detection lever to a light blocking position where light emission from the light emitting portion to the light receiving portion of the document detection sensor is blocked or to a light receiving position where the light emission can be received, the document detection sensor is in a light blocking state in which the emitted light is blocked when the light blocking body is in the light blocking position, and in a light receiving state in which the emitted light is received when the light blocking body is in the light receiving position, The control unit of the image forming apparatus is characterized in that when the document detection sensor is in the light-blocking state, it determines that the opening / closing cover is closed and the document is not set in the document tray, and when the document detection sensor is in the light-receiving state, it determines that the opening / closing cover is open, or it determines that the opening / closing cover is closed and the document is set in the document tray.

6. a jam detection sensor that detects a jam of the document transported through the document transport path; The control unit further switches the image forming apparatus from the jam detection state to a job resume state under the condition that the jam detection sensor switches from a jam detection state in which it detects a jam in the document to a jam non-detection state in which it does not detect a jam, and the opening / closing cover is closed and it is determined that the document is not set in the document tray at that time.

7. A display unit is provided, The image forming apparatus according to claim 6, wherein the control unit switches the image forming apparatus from the jam detection state to the job restart state, and switches the display of the display unit from a screen showing the jam detection state to a screen showing the job restart state.

8. 8. The image forming apparatus according to claim 6, wherein the control unit switches the image forming apparatus from the jam detection state to the job restart state, and further causes the pickup unit to execute an initial operation.

9. An image forming apparatus including: a document feeder having a document tray on which a document is set, a document set detection section for detecting that the document has been set on the document tray, and a pickup unit having a pickup roller for sending the document set on the document tray to a downstream side of a document transport path; and a control section for controlling the document feeder, a jam detection sensor that detects a jam of the document transported through the document transport path; The document set detection unit an original detection lever that is provided on an open / close cover that is openably provided above the original tray, the original detection lever being in a detection standby position for the original when the original is not set on the original tray, and being displaced to a detection position for the original by contact with the original when the original is set on the original tray; a document detection sensor provided in a device body of the document feeder, the document detection sensor having a light emitting section and a light receiving section; the document detection lever is provided with a light blocking body that is displaced in conjunction with a displacement of the document detection lever to a light blocking position where light emission from the light emitting portion to the light receiving portion of the document detection sensor is blocked or to a light receiving position where the light emission can be received, the document detection sensor is in a light blocking state in which the emitted light is blocked when the light blocking body is in the light blocking position, and in a light receiving state in which the emitted light is received when the light blocking body is in the light receiving position, The control unit determines that the opening / closing cover is open when the document detection sensor is in the light receiving state, or determines that the opening / closing cover is closed and the document is not set on the document tray, and determines that the opening / closing cover is closed and the document is set on the document tray when the document detection sensor is in the light blocking state, an image forming apparatus characterized in that, after the jam detection sensor switches from a jam detection state in which it detects a jam in the document to a jam non-detection state in which it does not detect a jam, when the document detection sensor switches from the light receiving state to the light blocking state and then back to the light receiving state, the image forming apparatus is switched from the jam detection state to a job resumption state.

10. A display unit is provided, The image forming apparatus according to claim 9, wherein the control unit switches the image forming apparatus from the jam detection state to the job restart state, and switches the display of the display unit from a screen showing the jam detection state to a screen showing the job restart state.

11. 11. The image forming apparatus according to claim 10, wherein the control unit switches the image forming apparatus from the jam detection state to the job restart state, and further causes the pickup unit to execute an initial operation.

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