JP2008207930A - Sheet feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeder capable of detecting placement of the sheet not influenced by the status such as wrinkles without providing a through hole on a placement base and enhancing durability of the device by eliminating a wire bundle to a device body. <P>SOLUTION: A light emitting element 31a is arranged above the placement base 2. A light emitting element 32 is arranged at a position opposed to a downstream side side surface of the placement base 2, and a row of light receiving elements 33b is arranged along a lifting direction of the placement base 2. A light path change member 34a for changing an advancement passage of the light emitted from the light emitting element 31a and the light emitting element 32 and leading it to the row of the light receiving element 33b is arranged on the placement base 2. By detecting the light or shutting off of the light by the light receiving element of the row 33b of the light receiving elements, existence of the sheet and a plurality of lifting positions of the placement base 2 are detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus that is provided in an image processing apparatus such as a copying machine, a printer, or a document scanner, and has a function of sequentially feeding a plurality of sheets placed on a mountable table.

  In order to keep the distance between the pickup roller and the uppermost sheet surface of the sheet bundle constant when the sheet feeding device provided in the copying machine, printer, document scanner, etc. feeds the sheet via the pickup roller, The seat mounting table can be moved up and down.

  Further, the sheet feeding device has means for detecting that the sheet is placed on the placing table in order to start feeding the sheet placed on the placing table and to detect the end of feeding. Is provided.

  As this detection means, for example, as shown in FIG. 2, when the light receiving / light emitting elements 21 and 22 are arranged in the mounting table in the direction of the original surface and the sheet is mounted on the mounting table, Some detect the reflected light.

  Further, as shown in FIG. 3, a photosensor 24 having a light receiving portion and a light emitting portion and a lever member 25 are arranged in the mounting table, and the lever is brought into contact with the sheet when the sheet is mounted on the mounting table. There is one that detects the displacement of the member 25 from the output change of the photosensor 24.

  However, when the light-receiving / light-emitting elements 21 and 22 and the photosensor 24 are arranged inside the mounting table, an electrical signal must be transmitted from the mounting table to the apparatus main body using the bundle 26. For this reason, there is a possibility that the bundle 26 repeatedly bends and stretches as the mounting table moves up and down, and the bundle 26 is deteriorated or broken. In this case, from the viewpoint of design and the like, the bundled wires 26 are usually not visible to the user and are arranged so that the user cannot touch them, so that it is difficult to notice deterioration or breakage.

  In addition, there has been proposed a technique for detecting the presence or absence of a sheet on a mounting table having an elevating function without arranging bundled wires on the mounting table and the apparatus main body (see Patent Document 1).

  In this proposal, light is irradiated from above the mounting table toward the mounting table provided with a through hole, and when the sheets are stacked, the reflected light from the sheet is received by the PSD light receiving element to increase the height of the stacked sheets. Detects. Further, when the sheets are not stacked, it is determined that the sheets are not stacked by detecting that the height of the sheet is smaller than a certain value by the through hole.

  However, in the above-mentioned Patent Document 1, since the PSD light receiving element measures the distance from the object based on the light receiving position, there is a possibility of erroneous detection when the sheet is wrinkled.

  In addition, since the mounting table requires a through hole, there is a problem that foreign matter falls into the through hole, and in the folding mounting table, the hole is exposed to the exterior of the apparatus.

  By the way, in a sheet feeding apparatus having a mounting table that can be moved up and down, it is often the case that the next sheet is placed immediately after the feeding of the sheet is finished and the feeding is resumed. The lifting range of the mounting table is determined based on the maximum loading amount on the mounting table, and every time the feeding of the sheet is finished, when waiting at the lowest lowered position where the maximum loading amount can be loaded, When a small amount is placed, the moving time of the placement table may be wasted.

  For this reason, there is an apparatus that can selectively stop the mounting table at several intermediate positions within the lifting range using a stepping motor or the like. In such an apparatus, when the mounting table is moved, the current position of the mounting table is calculated by controlling the amount of movement while counting the pulses applied to cause the stepping motor drive circuit to perform step driving. To do.

  However, since there may be a difference between the calculated mounting table position and the actual mounting table position due to motor out-of-step due to an excessive load or accumulation of errors due to repeated operations, it is periodically corrected to the reference position. Otherwise, it will not be possible to stop at the correct position.

  Therefore, even when a plurality of intermediate stop positions are provided in the mounting table raising / lowering range so that a small amount of sheets can be placed on the mounting table and quickly operated, the stop positions are periodically passed. Then, the position is corrected at the reference position and the intermediate stop position is returned again.

  In addition, a technique has been proposed in which a position detection switch for the mounting table is provided at a set stop position, and the signal is sent to the drive unit to accurately stop the mounting table at a position other than the reference position (see Patent Document 2). ).

However, in Patent Document 2, in order to accurately stop the mounting table at the stop position, it is necessary to arrange a position detection switch for each settable stop position, which increases the number of parts and increases the cost. .
JP 9-48549 A JP-A-1-187125

  It is an object of the present invention to enable detection of sheet placement without being affected by the state of wrinkles and the like without providing a through hole in the placement table, and to form a bundle between the main body and the placement table. It is an object of the present invention to provide a sheet feeding apparatus that can improve the durability of the apparatus and can provide a folding mechanism for the mounting table as needed without affecting the appearance.

  Further, the object of the present invention is to detect the unloading of the sheets, and determine the position of the mounting table, thereby quickly and surely mounting the sheet without returning to the reference position without adding a new detecting means. An object of the present invention is to provide a sheet feeding apparatus that can correct a position of a table.

  In order to achieve the above object, a sheet feeding apparatus according to the present invention is a sheet feeding apparatus including a mountable table on which a sheet is placed, and first irradiates light from above toward the table. A light emitting element, a second light emitting element that emits light toward the downstream side surface of the mounting table, and a plurality of light receiving elements along the ascending / descending direction of the mounting table so as to face the downstream side surface of the mounting table A light receiving element array disposed; and an optical path changing member that is disposed on the mounting table and changes a path of light emitted from the first light emitting element and the second light emitting element and guides the light to the light receiving element array. The position of the mounting table when any of the light receiving elements in the light receiving element array receives light irradiated from the second light emitting element and passed through the optical path changing member is a reference position, and the mounting table is the reference At the position, and other than the reference position When the mounting table is located at a position where any one of the light receiving elements in the light receiving element array can receive light irradiated from the first light emitting element and passed through the optical path changing member, the first light emitting element The presence or absence of a sheet on the mounting table is detected based on whether or not the light receiving element receives the light irradiated and passed through the optical path changing member.

  The sheet feeding device according to the present invention is a sheet feeding device including a mountable table on which a sheet is placed, and is arranged along the ascending / descending direction of the table, toward the downstream side surface of the table. A first light emitting element array composed of a plurality of first light emitting elements that irradiate light, and a second light emitting element that is disposed at a position different from the first light emitting element array and that irradiates light toward the downstream side surface of the mounting table. A plurality of light receiving elements facing the downstream side surface of the mounting table and arranged along the ascending / descending direction of the mounting table so as to correspond to the first light emitting element column; The light emitted from any one of the first light emitting elements in the first light emitting element array and the light emitted from the second light emitting elements correspond to the ascending / descending position of the table in the light receiving element array. An optical path changing member that leads to the light receiving element and placed on the mounting table A blocking member that displaces when the sheet is placed and blocks the optical path between the first light emitting element example of the optical path changing member and the light receiving element array when the sheet is displaced, The position of the mounting table when any of the light receiving elements in the light receiving element array receives the light irradiated from the two light emitting elements and passed through the optical path changing member is set as the reference position, and the mounting table is at the reference position And any of the light receiving elements in the light receiving element array can receive light that has passed through the optical path changing member after being irradiated from one of the first light emitting elements in the first light emitting element array at a position other than the reference position. When the light receiving element of the first light emitting element row receives the light that has been irradiated from the first light emitting element of the first light emitting element row and passed through the optical path changing member. Detect the presence or absence of seats on the table And features.

  The sheet feeding device according to the present invention is a sheet feeding device including a mountable table on which a sheet is placed, and is arranged along the ascending / descending direction of the table, toward the downstream side surface of the table. A first light emitting element array composed of a plurality of first light emitting elements that irradiate light, and a second light emitting element that is disposed at a position different from the first light emitting element array and that irradiates light toward the downstream side surface of the mounting table. A light receiving element capable of receiving the light emitted from the first light emitting element row and the second light emitting element, the first light emitting element of the first light emitting element row, An optical path changing member that changes the path of light emitted from the second light emitting element and emits the changed light; a light guide member that guides the light emitted from the optical path changing member to the light receiving element; Placed on the table, and a sheet is placed on the table. A blocking member that blocks the optical path between the first light emitting element row of the optical path changing member and the light guide member at the time of the displacement, and irradiates from the second light emitting element to The position of the mounting table when the light receiving element receives the light that has passed through the optical path changing member via the light guide member is set as a reference position, and when the mounting table is at the reference position, and other than the reference position When the mounting table is located at a position where the light receiving element can receive light that has been irradiated from the first light emitting element of any one of the first light emitting element rows and passed through the optical path changing member via the light guide member, The presence / absence of a sheet on the mounting table is detected based on whether or not the light receiving element receives light from the first light emitting element in the first light emitting element row and passes through the optical path changing member via the light guide member. It is characterized by doing.

  The sheet feeding device according to the present invention is a sheet feeding device including a mountable table on which a sheet is placed. The second light emitting device emits light toward the first light emitting element and the downstream side surface of the table. Limiting light emitted from the light emitting element, a light receiving element array composed of a plurality of light receiving elements arranged along the ascending / descending direction of the mounting table, and the light emitted from the first light emitting element to a single lifting position of the mounting table A light guide member that guides light to the mounting table, and a path of light that is arranged on the mounting table and that has been irradiated from the first light emitting element and passed through the light guiding member, and light that has been irradiated from the second light emitting element And the optical path changing member for guiding the light whose path has been changed to the light receiving element in the light receiving element row according to the ascending / descending position of the mounting table, and a sheet on the mounting table. It is displaced by being placed, and at the time of the displacement A light blocking element that blocks an optical path between the light guide member of the path changing member and the light receiving element array, and radiates light from the second light emitting element and passes the light path changing member to the light receiving element array. The position of the mounting table when any of the light receiving elements receives light is used as a reference position, and the light guide is irradiated from the first light emitting element when the mounting table is at the reference position and at a position other than the reference position. When the mounting table is located at a position where any of the light receiving elements in the light receiving element array can receive light that has passed through the optical path changing member via the member, the light is guided from the first light emitting element. The presence / absence of a sheet on the mounting table is detected based on whether or not a light receiving element in the light receiving element array receives light that has passed through the optical path changing member via a member.

  According to the present invention, it is possible to detect the placement of a sheet without being affected by the state of wrinkles and the like without providing a through hole in the placement table, and the durability of the device by eliminating the bundled wire to the main body. The folding mechanism of the mounting table can be provided as needed without affecting the appearance.

  Further, according to the present invention, in addition to the detection of unstacked sheets, the position of the mounting table is determined, so that a new detection unit is not added, and the sheet is quickly and reliably mounted without returning to the reference position. The position of the mounting table can be corrected.

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

(First embodiment)
First, a sheet feeding apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 4, the sheet feeding apparatus is provided with a placing table 2 for placing a sheet to be fed on the apparatus main body 1. A drive unit 5 such as a stepping motor is installed on the side of the mounting table 2, and a transmission gear 3 is provided on the drive shaft of the drive unit 5. The transmission gear 3 meshes with a rack 4 fixed to the mounting table 2, and accordingly, the mounting table 2 is driven up and down via the transmission gear 3 and the rack 4 by driving of the driving unit 5.

  Further, the sheet placed on the placing table 2 is taken into the apparatus main body 1 by the pickup roller 11 that contacts the uppermost sheet of the sheet bundle. A sheet taken into the apparatus main body 1 is fed into the apparatus main body 1 by a feeding roller 12 and a separation roller 13 as feeding means. When a plurality of sheets are fed, one sheet is fed. Separated one by one. A registration roller pair 14 is arranged on the downstream side of the feeding roller 12 and the separation roller 13, and the registration roller pair 14 conveys the sheet while correcting it when the sheet is fed in a skewed state. The sheet that has passed through the registration roller pair 14 is discharged out of the apparatus through the conveyance roller pair 15 and the discharge roller pair 16. In the case of a scanner, an image reading unit (not shown) is disposed between the registration roller pair 14 and the conveyance roller pair 15 in the drawing.

  As shown in FIG. 1, the apparatus main body 1 includes a first light emitting element 31 a that emits light from above the mounting table 2 toward the mounting table 2, and a downstream side facing the apparatus main body 1 side of the mounting table 2. A second light emitting element 32 that irradiates light toward the side surface, and a position separated from the second light emitting element 32 in the width direction perpendicular to the sheet feeding direction of the mounting table 2 along the ascending / descending direction of the mounting table 2. And a light receiving element array 33b composed of a plurality of light receiving elements arranged at a predetermined interval.

  Further, on the mounting table 2, an optical path changing member that guides both the light emitted from the first light emitting element 31a and the light emitted from the second light emitting element 32 to the light receiving element array 33b while changing the traveling direction of the light. 34a is arranged.

  The optical path changing member 34a has a shape that can always ensure an optical path for guiding light from the second light emitting element 32 to the lowermost light receiving element of the light receiving element array 33b when the mounting table 2 is at the reference position. . In this embodiment, a light guide made of transparent resin is used as the optical path changing member 34a.

  Next, the setting of the standby position of the mounting table 2 will be described.

  In a normal state, when the power is turned on, a CPU (not shown) as a control means places the mounting table 2 in the vicinity of the lower limit so that the mounting table 2 can be mounted on the mounting table 2 with the maximum sheet loading capacity. To stand by. The user performs a process start operation after placing the sheet on the placement table 2.

  By this operation, the sheet feeding device is controlled by the CPU to start feeding, and performs a series of processes. After the feeding of all the sheets is finished, the mounting table 2 is set at the reference position or the maximum stacking amount of sheets. Returning to the intermediate standby position, it prepares for the process that is started by the user operating again. The standby position of the mounting table 2 can be set by the user according to the amount of sheets placed on the mounting table 2.

  Next, the sheet feeding operation will be described.

  First, an operation when the reference position of the mounting table 2 is selected and set as the standby position of the mounting table 2 will be described.

  When the user turns on a power switch (not shown), the sheet feeding apparatus is in an operating state, and the CPU as the control unit irradiates the second light emitting element 32 with light, and the position of the mounting table 2 becomes the reference position. To control.

  Specifically, when the mounting table 2 is moved up and down so that the second light emitting element 32 and the optical path changing member 34b face each other, the second light emitting element 32 emits light that has passed through the optical path changing member 34b. The light receiving element at the lowermost end of the element row 33b receives light. The CPU detects this light reception and recognizes it as a reference position, and controls the drive unit 5 to stop the mounting table 2.

  Next, the CPU turns off the second light emitting element 32 while irradiating the first light emitting element 31a with light, and the sheet is placed on the table depending on whether or not the lowermost light receiving element of the light receiving element row 33b receives light. 2 is determined. If it is determined that the sheet is placed, it is prepared for the user's operation to instruct execution of the paper feed start process. If it is determined that the sheet is not placed at this time, the sheet feeding apparatus does not perform processing even if it is instructed to execute the paper feeding start processing.

  Next, when the execution of the paper feeding start process is instructed by the user's operation, the CPU raises the mounting table 2 to a position where the uppermost sheet of the sheet bundle placed on the mounting table 2 contacts the pickup roller 11. The drive unit 5 is controlled so that At this time, whether or not the uppermost sheet has reached a position in contact with the pickup roller 11 is detected using a document position sensor (not shown).

  Next, the sheets are taken into the apparatus main body 1 by the pickup roller 11, and are fed into the apparatus main body 1 by the feeding roller 12 and the separation roller 13, and when a plurality of sheets are taken in, the sheets are separated one by one. Is done. In order to prevent the distance between the sheet placed on the placement table 2 and the pickup roller 11 from being increased as the feeding proceeds, the CPU places the placement table 2 on the pickup roller 11 and the placement table 2. The drive unit 5 is controlled so as to be gradually raised so that the distance from the sheet is constant.

  When the feeding of all the sheets placed on the mounting table 2 is completed, the CPU turns off the first light emitting element 31a and causes the second light emitting element 32 to emit light, and drives the mounting table 2 toward the reference position. The unit 5 is controlled.

  When the light emitted from the second light emitting element 32 passes through the optical path changing member 34a and is received by the light receiving element at the lowermost end of the light receiving element array 33b, the CPU detects this, and the mounting table 2 becomes the reference. The drive unit 5 is controlled to recognize the position and stop the mounting table 2.

  Next, the CPU turns off the second light emitting element 32 and causes the first light emitting element 31a to emit light again so that the light passing through the optical path changing member 34a is received by the light receiving element at the lowermost end of the light receiving element row 33b. Whether or not the user has placed the sheet on the placing table 2 again is detected by blocking the light emitted by the first light emitting element 31a.

  Next, a case where a position other than the reference position is set as the standby position of the mounting table 2 will be described.

  The operation from when the user turns on the power switch until obtaining the reference position of the mounting table 2 is the same as the operation when the reference position is set as the standby position.

  After recognizing the reference position of the mounting table 2, the CPU calculates the number of pulses necessary for the movement of the mounting table 2, outputs a pulse, and moves the mounting table 2 to the set standby position. 5 is controlled. Next, the CPU causes the first light emitting element 31a to emit light and sets whether or not the sheet is placed on the placing table 2 depending on whether or not the light receiving element row 33b is receiving light, and the sheet feeding start process. Prepare for.

  Also in this case, if the CPU cannot detect that the sheet is placed on the placement table 2 as in the case where the reference position is set as the stop position, the sheet feeding device instructs execution of the sheet feeding start process. If it is done, no processing is performed.

  When document placement is detected, when the execution of paper feed start processing is commanded by the user's operation, the CPU sets the placement table 2 in the same manner as when the reference position is set as the standby position. Raise the paper feed operation. The sheet feeding operation is the same as that when the reference position is set as the standby position.

  When the feeding operation of all the sheets placed on the placement table 2 is finished, the CPU drives the placement table 2 toward the set standby position with the first light emitting element 31a emitting light. The unit 5 is controlled.

  Next, unlike the case where the reference position is set as the standby position, the light emitted from the first light emitting element 31a passes through the optical path changing member 34a and reaches a preset standby position in the light receiving element array 33b. When the light receiving element in the corresponding position receives light, the CPU detects this, recognizes that the mounting table 2 is in the standby position, and controls the drive unit 5 to stop the mounting table 2.

  Next, the CPU raises and lowers the position of the mounting table 2 under the control of the driving unit 5 to correct the position to an accurate position, and then continues to irradiate light from the first light emitting element 31a and pass through the optical path changing member 34a. Is prepared for the user to place the sheet on the placing table 2 in a state where the light is received by the light receiving element row 33b. And CPU detects that the sheet | seat was again mounted in the mounting base 2 by the irradiation light of the 1st light emitting element 31a being interrupted | blocked.

  In this way, since the position of the mounting table 2 can be corrected at an arbitrary standby position of the mounting table 2 without the mounting table 2 returning to the reference position, the total movement distance of the mounting table 2 is shortened. It becomes possible to reduce waiting time. In addition, when the mounting table 2 is stopped at the reference position and other standby positions, it can be detected whether or not a sheet is mounted on the mounting table 2 at all times. It is also possible to start the operation.

  As described above, in the present embodiment, it is possible to detect the presence / absence of sheet stacking without being affected by the state of wrinkles or the like without providing a through hole in the mounting table 2 and to bundle the apparatus main body 1. Therefore, there is no inconvenience such that the bundle wire is repeatedly bent and stretched and broken, and the durability of the apparatus can be improved.

  In the present embodiment, the folding table 2 is not provided with a folding mechanism. However, when the folding table 2 is provided with a folding mechanism, it is not necessary to provide a through hole. It can be provided without giving.

  Further, in addition to detecting the unloading of sheets, it is determined that the mounting table 2 is in the standby position, so that it is quickly and reliably mounted without returning to the reference position without adding a new detecting means. The position of the mounting table 2 can be corrected.

  Furthermore, since the sensor for detecting the presence / absence of the sheet and the sensor for correcting the position of the mounting table 2 are made common, it is not necessary to add a new detecting means, thereby reducing the cost and the installation space of the sensor. can do.

(Second Embodiment)
Next, a sheet feeding apparatus according to the second embodiment of the present invention will be described with reference to FIG. In this embodiment, different parts from the first embodiment are mainly described, and overlapping parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted or simplified.

  In this embodiment, as shown in FIG. 5, the apparatus body 1 includes a second light emitting element 32 that emits light toward a downstream side surface of the mounting table 2 facing the apparatus body 1, and the second light emitting element 32. A light receiving element comprising a plurality of light receiving elements disposed at predetermined intervals along the ascending / descending direction of the mounting table 2 at a position spaced apart to one side in the width direction perpendicular to the sheet feeding direction of the mounting table 2 A row 33b and a position spaced apart from the light receiving element row 33b on one side in the width direction perpendicular to the sheet feeding direction of the mounting table 2 are arranged at predetermined intervals along the ascending / descending direction of the mounting table 2. And a first light-emitting element array 31b composed of a plurality of light-emitting elements that irradiate light toward a downstream side surface facing the apparatus main body 1 side of the mounting table 2.

  On the other hand, the mounting table 2 changes the path of the light irradiated by the light emitting elements in the first light emitting element row 31b and guides it to the corresponding light receiving elements in the light receiving element row 33b, and also changes the light emitted by the second light emitting elements 32 An optical path changing member 34b that changes the path and guides it to the light receiving element at the lowermost end of the light receiving element row 33b, and rotates in conjunction with the placement of the sheet on the mounting table 2, and the first light emitting element row of the optical path changing member 34b. And a lever member 25 as a blocking member for blocking the optical path between 31b and the light receiving element array 33b.

  The optical path changing member 34b has a shape that cannot block the optical path from the second light emitting element 32 to the light receiving element array 33b for obtaining the reference position of the mounting table 2. In this embodiment, a light guide made of transparent resin is used as the optical path changing member 34b.

  When detecting the stacking of sheets on the mounting table 2, in the first embodiment, the sheet blocks the light emitted from the light emitting element 31 a so as to detect the stacking of sheets on the mounting table 2. On the other hand, in the present embodiment, the light loaded from the light emitting elements in the light emitting element row 31b and transmitted through the optical path changing member 34b is pressed by the sheet and the rotated lever member 25 blocks the sheets so that the sheets are stacked on the mounting table 2. Detect.

  According to the present embodiment, since the optical path for detecting whether or not the sheet is placed on the mounting table 2 is not disposed outside the apparatus, it is possible to avoid the interference of the optical path due to dust or the like. Other configurations and operational effects are the same as those of the first embodiment.

(Third embodiment)
Next, a sheet feeding apparatus according to the third embodiment of the present invention will be described with reference to FIG. In this embodiment, different parts from the first and second embodiments are mainly described, and overlapping parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted or simplified.

  In this embodiment, as shown in FIG. 6, the apparatus main body 1 includes a second light emitting element 32 that emits light toward a downstream side surface facing the apparatus main body 1 side of the mounting table 2, and the second light emitting element 32. A light receiving element 33a disposed at a position spaced apart on one side in the width direction perpendicular to the sheet feeding direction of the mounting table 2, and orthogonal to the sheet feeding direction of the mounting table 2 with respect to the light receiving element 33a. Are arranged at predetermined intervals along the ascending / descending direction of the mounting table 2 at positions spaced apart on one side in the width direction to be irradiated, and irradiate light toward a downstream side surface facing the apparatus main body 1 side of the mounting table 2. And a first light emitting element row 31b made of the above light emitting elements.

  Further, the apparatus main body 1 guides the light irradiated by the second light emitting element 32 and transmitted through the optical path changing member 34b to the light receiving element 33a when the mounting table 2 is at the lowermost reference position, so that the light emitting element row 31b It has an optical path concentrating member 35 as a light guide member that guides the light irradiated by the light emitting element and transmitted through the optical path changing member 34b to the light receiving element 33a when the mounting table 2 is at the reference position and the predetermined standby position.

  The light that has been irradiated by the second light emitting element 32 and transmitted through the optical path changing member 34b and the light that has been irradiated by the lowermost light emitting element of the light emitting element array 31b and transmitted through the optical path changing member 34b are incident on the optical path collecting member 35. The first incident port, the light emitting element at the intermediate position of the light emitting element row 31b, and the second incident port where the light transmitted through the optical path changing member 34b is incident, the uppermost light emitting element of the light emitting element row 31b emits light. And a third entrance through which the light transmitted through the optical path changing member 34b enters.

  Further, the optical path concentrating member 35 is provided with an exit port through which light incident from the first to third entrance ports is emitted, and the exit port is disposed to face the light receiving element 33a.

  On the other hand, the mounting table 2 changes the path of light emitted by the light emitting elements of the first light emitting element array 31b and the second light emitting element 32 according to the lift position of the mounting table 2, and the light whose path has been changed is an optical path. An optical path changing member 34b that leads to one of the first to third entrances of the collecting member 35, and a first light emitting element row 31b of the optical path changing member 34b that rotates in conjunction with the placement of the sheet on the mounting table 2. And a lever member 25 as a blocking member that blocks the optical path between the optical path collecting member 35 and the optical path collecting member 35.

  The optical path changing member 34b has a shape that cannot block the optical path from the second light emitting element 32 to obtain the reference position of the mounting table 2 to the optical path collecting member 35. In this embodiment, a light guide made of transparent resin is used as the optical path changing member 34b and the optical path consolidating member 35.

  Here, in the second embodiment, the light path irradiated by the light emitting elements of the first light emitting element row 31b is changed by the optical path changing member 34b and led to the corresponding light receiving elements of the light receiving element row 33b. While the light path irradiated by the two light emitting elements 32 is changed by the optical path changing member 34b and led to the light receiving element at the lowermost end of the light receiving element row 33b, in the present embodiment, the light emitting elements of the first light emitting element row 31b. The path of the light irradiated by is changed by the optical path changing member 34b and the light whose path has been changed is guided to the light emitting element 33a through the optical path collecting member 35, and the path of the light irradiated by the second light emitting element 32 is changed to the optical path changing member. The light that has been changed by 34 b and whose path has been changed is guided to the light emitting element 33 a through the optical path collecting member 35. Other configurations and operational effects are the same as those of the first and second embodiments.

(Fourth embodiment)
Next, a sheet feeding apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, different parts from the first and second embodiments are mainly described, and overlapping parts are denoted by the same reference numerals in the drawings, and the description thereof is omitted or simplified.

  In this embodiment, as shown in FIG. 7, the apparatus main body 1 has a first light emitting element 31 c that emits light toward a downstream side surface facing the apparatus main body 1 side of the mounting table 2, and the first light emitting element 31 c. A second light emitting element 32 that is disposed at a position spaced apart on one side in the width direction orthogonal to the sheet feeding direction of the mounting table 2 and emits light toward a downstream side surface facing the apparatus main body 1 side of the mounting table 2; A light receiving element array 33b composed of a plurality of light receiving elements arranged at predetermined intervals along the ascending / descending direction of the mounting table 2 at a position between the second light emitting element 32 and the first light emitting element 31c; An optical path diffusing member 36 as a light guide member that guides the light emitted by 31c to the optical path changing member 34b regardless of the elevation position of the mounting table 2; In this embodiment, the light path diffusing member 36 is obtained by changing the plurality of entrances of the third embodiment (see FIG. 7) to the exit, but from all the wall surfaces of the light path diffusing member. Those that emit light can also be used.

  On the other hand, the mounting table 2 changes the path of the light irradiated by the first light emitting element 31c and transmitted through the optical path diffusing member 36 and the light irradiated by the second light emitting element 32, and the light whose path has been changed is received by the light receiving element array. An optical path changing member 34b that leads to 33b and a blocking member that rotates in conjunction with the placement of the sheet on the mounting table 2 and blocks the optical path between the optical path diffusing member 36 of the optical path changing member 34b and the light receiving element array 33b. And a lever member 25.

  The optical path changing member 34b has a shape that cannot block the optical path from the second light emitting element 32 to the light receiving element array 33b for obtaining the reference position of the mounting table 2. In this embodiment, a light guide made of transparent resin is used as the optical path changing member 34b and the optical path diffusing member 36.

  Here, in the second embodiment, the light path irradiated by the light emitting elements of the first light emitting element row 31b is changed by the optical path changing member 34b and led to the corresponding light receiving elements of the light receiving element row 33b. While the light path irradiated by the two light emitting elements 32 is changed by the optical path changing member 34b and led to the light receiving element at the lowermost end of the light receiving element row 33b, in the present embodiment, the light irradiated by the first light emitting element 31c is used. Is guided to the optical path changing member 34b through the optical path diffusing member 36, and the path of the guided light is changed by the optical path changing member 34b to the light receiving elements of the light receiving element row 33b corresponding to the lift position of the mounting table 2. At the same time, the path of the light irradiated by the second light emitting element 32 is changed by the optical path changing member 34b and led to the light receiving element at the lowermost end of the light receiving element row 33b. Other configurations and operational effects are the same as those of the first and second embodiments.

  In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in each of the above embodiments, a light guide made of a transparent resin is used as an optical path changing member, an optical path aggregating member, and an optical path diffusing member as a light guide member, but instead of this, a mirror, a half mirror, a prism, a light A fiber or the like may be used. Moreover, you may comprise an optical path change member, an optical path aggregation member, and an optical path diffusion member by combining several members, respectively.

  Moreover, in the said 2nd-4th embodiment, although the lever member was illustrated as an interruption | blocking member which interrupts | blocks the optical path of an optical path change member, it is not limited to this, The optical path of an optical path change member is interrupted by being pressed by a sheet | seat. If it is a member, you may use another interruption | blocking member.

FIG. 3 is a perspective view for explaining the sheet feeding apparatus according to the first embodiment of the present invention. It is a perspective view for demonstrating the conventional sheet feeding apparatus using a light receiving element and a light emitting element. It is a perspective view for demonstrating the conventional sheet feeding apparatus using a phototransistor. It is a schematic sectional drawing for demonstrating the sheet feeding apparatus which is the 1st Embodiment of this invention. It is a perspective view for demonstrating the sheet feeding apparatus which is the 2nd Embodiment of this invention. It is a perspective view for demonstrating the sheet feeding apparatus which is the 3rd Embodiment of this invention. FIG. 10 is a perspective view for explaining a sheet feeding apparatus according to a fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Mounting stand 3 Transmission gear 4 Rack 5 Drive part 11 Pickup roller 12 Feed roller 13 Separation roller 14 Registration roller pair 15 Conveyance roller pair 16 Paper discharge roller pair 25 Lever member 31a First light emitting element 31b First light emitting element Row 31c First light emitting element 32 Second light emitting element 33a Light receiving element 33b Light receiving element row 34a Optical path changing member 34b Optical path changing member 35 Optical path consolidating member 36 Optical path diffusing member

Claims (5)

In a sheet feeding apparatus including a mountable table on which a sheet is mounted,
A first light emitting element that emits light from above toward the mounting table;
A second light emitting element that emits light toward the downstream side surface of the mounting table;
A plurality of light receiving elements arranged along the ascending / descending direction of the mounting table so as to face the downstream side surface of the mounting table;
An optical path changing member that is arranged on the mounting table and changes a path of light emitted from the first light emitting element and the second light emitting element and guides it to the light receiving element array;
The reference position is the position of the mounting table when any one of the light receiving elements in the light receiving element row receives light irradiated from the second light emitting element and passed through the optical path changing member,
The light receiving element in one of the light receiving element rows receives light that has been irradiated from the first light emitting element and passed through the optical path changing member at a position other than the reference position when the mounting table is at the reference position. When there is a mounting table in a possible position, detecting the presence or absence of a sheet on the mounting table by whether or not the light receiving element receives light that has been irradiated from the first light emitting element and passed through the optical path changing member A sheet feeding device characterized by the above. In a sheet feeding apparatus including a mountable table on which a sheet is mounted,
A first light-emitting element array composed of a plurality of first light-emitting elements that are arranged along the ascending / descending direction of the mounting table and irradiates light toward the downstream side surface of the mounting table;
A second light emitting element that is arranged at a different position from the first light emitting element row and irradiates light toward the downstream side surface of the mounting table;
A plurality of light receiving elements facing the downstream side surface of the mounting table, and a light receiving element array disposed along the ascending / descending direction of the mounting table so as to correspond to the first light emitting element array;
The light emitted from the first light emitting element in any one of the first light emitting element rows and the light emitted from the second light emitting element are placed on the placing table in the lifting position of the placing table in the light receiving element row. An optical path changing member that leads to a corresponding light receiving element;
A blocking member that is disposed on the mounting table and is displaced when the sheet is placed, and that blocks the optical path between the first light emitting element example of the optical path changing member and the light receiving element array at the time of the displacement, With
The reference position is the position of the mounting table when any of the light receiving elements in the light receiving element row receives light irradiated from the second light emitting element and passed through the optical path changing member,
When the mounting table is in the reference position, and the light that has been irradiated from any of the first light emitting elements in the first light emitting element array and passed through the optical path changing member other than the reference position, When the mounting table is located at a position where any one of the light receiving elements can receive light, the light emitted from the first light emitting element of the first light emitting element array and passed through the optical path changing member is received by the light receiving element of the light receiving element array A sheet feeding apparatus that detects the presence or absence of a sheet on the mounting table according to whether or not a light is received. In a sheet feeding apparatus including a mountable table on which a sheet is mounted,
A first light-emitting element array composed of a plurality of first light-emitting elements that are arranged along the ascending / descending direction of the mounting table and irradiates light toward the downstream side surface of the mounting table;
A second light emitting element that is arranged at a different position from the first light emitting element row and irradiates light toward the downstream side surface of the mounting table;
A light receiving element capable of receiving light emitted from the first light emitting element and the second light emitting element of the first light emitting element row;
An optical path changing member that is arranged on the mounting table and changes the path of light emitted from the first light emitting element and the second light emitting element of the first light emitting element row and emits the light whose path has been changed,
A light guide member for guiding light emitted from the optical path changing member to the light receiving element;
Disposed by placing the sheet on the mounting table and placing a sheet on the mounting table, and blocking the optical path between the first light emitting element array of the optical path changing member and the light guide member at the time of the displacement. A blocking member,
The position of the mounting table as a reference position when the light receiving element receives light that has been irradiated from the second light emitting element and passed through the optical path changing member via the light guide member,
When the mounting table is at the reference position, and light from the first light emitting element in any of the first light emitting element rows other than the reference position and passed through the optical path changing member is passed through the light guide member. When the mounting table is at a position where the light receiving element can receive light, the light received from the first light emitting element of the first light emitting element array and passed through the optical path changing member is received through the light guide member. A sheet feeding apparatus that detects the presence or absence of a sheet on the mounting table according to whether or not an element receives light. In a sheet feeding apparatus including a mountable table on which a sheet is mounted,
A first light emitting element;
A second light emitting element that emits light toward the downstream side surface of the mounting table;
A light receiving element array composed of a plurality of light receiving elements arranged along the ascending / descending direction of the mounting table;
A light guide member that guides light emitted from the first light emitting element to the mounting table without limiting to the single lifting position of the mounting table;
The light that is arranged on the mounting table, changes the path of the light irradiated from the first light emitting element and passes through the light guide member and the light irradiated from the second light emitting element, and changes the path of the light. An optical path changing member that leads to any one of the light receiving elements in the light receiving element row according to the lift position;
A blocking member that is disposed on the mounting table and is displaced by placing a sheet on the mounting table, and blocks the optical path between the light guide member and the light receiving element array of the optical path changing member when the sheet is displaced. And comprising
The reference position is the position of the mounting table when any one of the light receiving elements in the light receiving element row receives light irradiated from the second light emitting element and passed through the optical path changing member,
When the mounting table is at the reference position, and any light in the light receiving element array is irradiated from the first light emitting element at a position other than the reference position and passes through the optical path changing member through the light guide member. When the light receiving element is at a position where the light receiving element can receive light, the light receiving element of the light receiving element array emits the light irradiated from the first light emitting element and passed through the optical path changing member via the light guide member. A sheet feeding apparatus that detects the presence or absence of a sheet on the table according to whether light is received or not.   When the setting table is set to stand by at a specified stop position other than the reference position, when the setting table returns to the reference position after feeding a sheet, irradiation is performed from the first light emitting element at the specified stop position. 5. The apparatus according to claim 1, further comprising: a control unit configured to control the mounting table to stop based on a signal output from the light receiving element when the light receiving element receives the received light. The sheet feeding apparatus according to the description.

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