JP4416559B2 - Paper detecting device and paper feeding device equipped with the same - Google Patents

Description

  The present invention relates to a paper detection device that can be applied to a paper feeding device, a paper conveyance device, and the like mounted in an image forming apparatus such as a copying machine or a printer. The present invention also relates to a paper feeding device equipped with this paper detection device.

  The paper detection device is used to detect whether or not a paper is present at a predetermined position in a paper feeding device, a paper transporting device, or the like mounted on an image forming apparatus such as a copying machine or a printer. The paper detection device is used not only for identifying the presence of paper but also for detecting the presence or absence of paper jam.

The paper detection device includes an actuator that rotates when the paper abuts, a support member that supports the actuator, and a sensor that detects displacement of the actuator. The actuator is provided with a sheet abutting portion on which the sheet abuts, a sensor interference portion used for detection by a sensor, and a rotation shaft, and the actuator is rotatable about this axis. The support member includes a hole, and supports the actuator by passing the rotation shaft of the actuator through the hole. Examples of the paper detection device having such a configuration can be found in Patent Documents 1 and 2.
Japanese Unexamined Patent Publication No. 7-144789 (page 3-4, FIG. 1) JP-A-11-59961 (page 3-4, FIG. 2)

  In the paper detection device (recording paper detection device) described in Patent Documents 1 and 2, the rotation shaft of the actuator is inserted into a support member (holding body, support stay) that supports the actuator (contact arm, detection lever). A hole is formed. Burr toward the inside of the hole is likely to occur in the hole portion of such a support member during production. This burr becomes an obstacle to the rotation of the shaft, which may cause malfunction of the actuator.

  Each of these supporting members is provided so as to protrude from the frame, and is provided with a hole for inserting the rotation shaft of the actuator in a direction orthogonal to the protruding direction. Cost increases. In the case of sheet metal, two steps of drilling and bending (cutting and raising) are required, which increases the manufacturing cost. Furthermore, since the occupation area of the support member increases due to the protrusion, the apparatus may be increased in size.

  In the paper detection device described in Patent Document 1, a pressing groove for pressing the rotation shaft from the outside of the supporting member toward the hole is formed in the supporting member. Various problems occur when the width dimension of the indentation groove is inaccurate. For example, when the dimension of the groove width is small, the rotating shaft is very tight when it is pushed into the hole, and the rotating shaft may not enter or may be damaged. On the other hand, when the dimension of the groove width is large, problems such as easy dropping of the rotating shaft may occur.

  In the recording paper detection apparatus described in Patent Document 2, both ends of the rotation shaft of the actuator are supported by two support members. In order to attach the rotating shaft to the hole of the supporting member, both ends of the rotating shaft must be inserted into each of the two supporting members while pushing or tilting one or both of them outward. Therefore, there is a high possibility that the support member will be broken when it is tilted.

  The present invention has been made in view of the above points, and can provide a space-saving and stable operation of the actuator with a simple configuration without providing a support member having a hole that is difficult to form or attach to a shaft. An object of the present invention is to provide a sheet detection device that can be obtained. It is another object of the present invention to provide a high-performance paper feeding device equipped with such a paper detection device.

  In order to solve the above problems, in the present invention, a frame provided with a concave bent portion, an actuator that projects a shaft portion on both sides and rotates around the shaft portion by contact of paper, A sensor for detecting displacement; and a support member for the sensor. The shaft portion of the actuator is positioned at a bent portion of the frame, and the sensor support member is attached to the frame, whereby the shaft portion Therefore, it was decided to prevent escape from the bent portion.

  Further, the actuator has a bell crank shape in a front shape perpendicular to the rotation axis, the shaft portion is provided at a corner portion of the bell crank, and a paper contact portion where the paper is in contact with one end of the bell crank. The other end is provided with a sensor interference unit used for detecting displacement by the sensor.

  The sensor is composed of a transmissive optical sensor.

  The transmissive optical sensor includes a main body, a light emitting unit protruding from the main body, and a light receiving unit. The optical axis of the transmissive optical sensor is parallel to the rotation axis of the actuator. The direction in which the light emitting part and the light receiving part protrude from the main body part is provided so as to be parallel to a plane constituting one surface of the bent part.

  In the present invention, the paper detection device is mounted on the paper feeding device.

  The paper feeding device includes a base frame, a push-up plate on which paper is stacked and supported by the base frame so as to be rotatable in a vertical plane parallel to the paper supply direction, and a paper loaded on the push-up plate. A paper feeding device that feeds the paper from the uppermost layer one by one; and a biasing means that biases the push-up plate toward a position where the uppermost layer of the paper on the push-up plate contacts a paper feed roller provided in the paper feed device. A paper feed cam mechanism that allows the push-up plate to move to a position where the uppermost layer of the paper on the push-up plate contacts the paper feed roller each time the paper is fed, and the frame of the paper detection device The base frame supports the plate, and the actuator is provided below the push-up plate and between the push-up plate and the base frame.

  In the paper feeding device, the downstream end of the push-up plate in the paper transport direction is close to the base frame, and an uneven portion is formed in each member so that these members mesh with each other at the close location. Thus, by providing the actuator in the recess of the base frame, the movement of the actuator in the axial direction is prevented.

  According to the configuration of the present invention, a frame provided with a concave bent portion, an actuator that rotates about a shaft portion protruding on both sides, a sensor that detects the displacement of the actuator, and a support member for the sensor, The shaft portion of the actuator is positioned at the bent portion of the frame, and the sensor support member is attached to the frame, thereby preventing the shaft portion from escaping from the bent portion. In order to support, there is no support member provided with a hole and protruding from the frame. And since an actuator is supported only by attaching a sensor support member to a frame, attachment of an actuator is very simple. In this way, there is no need to worry about the generation of burrs or the attachment of a cramped shaft to the support member of the actuator. Therefore, with a simple configuration, it is possible to obtain a stable actuator operation in a small space.

  In addition, since the actuator has a bell crank shape in the front shape perpendicular to the rotation axis, and the shaft portion is provided at the corner portion of the bell crank, the shaft portion of such an actuator is connected to the concave shape of the frame. By being positioned at the bent portion, the actuator is disposed along the surfaces on both sides of the bent portion. Therefore, since the actuator can be disposed close to the frame, further space saving can be achieved. In addition, since the paper abutting portion where the paper abuts on one end of the bell crank is provided and the sensor interference portion used for detecting the displacement by the sensor is provided on the other end, a minute amount of the paper abutting portion is provided. Can be converted into a large displacement of the sensor interference part. Thereby, the sensitivity of the sensor can be increased with respect to the contact of the sheet with the actuator, and the sheet can be detected with high accuracy.

  In addition, since the sensor is composed of a transmissive optical sensor, a transmissive optical sensor that is widely used as a sensor is generally used, and paper detection can be performed with an inexpensive and simple configuration. It is.

  The transmissive optical sensor includes a main body, a light emitting section protruding from the main body, and a light receiving section. The optical axis of the transmissive optical sensor is parallel to the rotation axis of the actuator, and the main body. Since the light emitting part and the direction in which the light receiving part protrudes from the part is provided so as to be parallel to a plane constituting one surface of the bent part, the optical sensor can be arranged close to the frame. The area occupied by the optical sensor can be reduced. Therefore, it is possible to further reduce the space in addition to being able to arrange the actuator close to the frame.

  Further, in the present invention, since the paper detection device is mounted on the paper feeding device, it is possible to save space by a simple configuration without providing a support member having a hole that is difficult to form or to attach a shaft. Thus, a high-performance sheet feeding device capable of obtaining a stable operation of the actuator can be obtained.

  In addition, the paper feeding device includes a base frame, a push-up plate on which paper is stacked and rotatably supported by the base frame, a paper feeding device that supplies and feeds one sheet at a time from the uppermost layer of paper, and a paper feeding device for the paper feeding device. An urging unit that urges the push-up plate toward a position where the uppermost layer of the paper is in contact with the paper roller, and a feed that allows the push-up plate to move to a position where the uppermost layer of the paper is in contact with the paper feed roller every time the paper is supplied. A paper cam mechanism, wherein the frame of the paper detection device is a base frame that supports the push-up plate, and the actuator is provided below the push-up plate and between the push-up plate and the base frame. . Thereby, in the paper feeding device having the above-described configuration, the paper detection means can be arranged in a very small space between the push-up plate and the base frame. Therefore, an increase in size of the paper feeding device can be prevented, and a more compact paper feeding device can be provided.

  Further, in the paper feeding device, the downstream end of the push-up plate in the paper transport direction is close to the base frame, and in this proximity, an uneven portion that engages with each other is formed on each member. Since the actuator is provided in the concave portion of the base frame, the paper detecting device is arranged by using the concave and convex concave portions provided to prevent the paper from entering between the push-up plate and the base frame. Can do. As a result, when the paper detection device is arranged, a portion formed for a purpose different from the arrangement of the paper detection device on the base frame can be used, so that the space can be effectively used. Furthermore, as described above, since the actuator is provided in the concave portion of the base frame, the movement of the actuator in the axial direction is prevented, so that the position of the actuator in the axial direction can be determined without providing a separate support member. it can. Therefore, the number of parts and materials used can be reduced, and the cost of the sheet feeding device can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, it is assumed that the paper detection device of the present invention is used in a manual paper feed unit that is a paper feed device disposed on the side surface of the image forming apparatus.

  First, the outline of the structure of a manual sheet feeding unit, which is a sheet feeding device including the sheet detection device of the present invention, will be described with reference to FIGS. FIG. 1 is a perspective view showing a manual sheet feeder provided with a paper detection device and its periphery, FIG. 2 is a schematic vertical sectional front view of the manual sheet feeder, and FIG. 3 shows the vicinity of the manual sheet feeder similar to FIG. FIG. 2 is an enlarged perspective view showing a state cut at a substantially central portion in the paper width direction perpendicular to the paper supply direction. In these drawings, only a part of the frame having a manual sheet feeding portion is shown for the image forming apparatus main body. An arrow A in FIG. 1 indicates the front of the image forming apparatus.

  In FIG. 1, the manual sheet feeder 1 is provided on the left side surface with respect to the front surface indicated by an arrow A of an image forming apparatus (not shown). The manual sheet feeder 1 uses a part of the main body frame 100 of the image forming apparatus as the base frame 10. In the manual paper feed unit 1, the paper is fed in the direction of arrow B toward the inside of the image forming apparatus. The sheet feeding direction will be described in detail. In FIG. 2, the sheet is placed on the manual sheet feeding unit 1 from the left side (arrow C), and sent out to the upper right (arrow D).

  In addition to the base frame 10, the manual paper feed unit 1 includes a push-up plate 20, a paper feeding device 30, a push-up plate urging means (not shown), a paper feed cam mechanism 40, and a paper detection device 50.

  As shown in FIGS. 2 and 3, the base frame 10 constitutes a base portion extending from the bottom portion 11 to the right side wall portion 12 of the manual sheet feeding portion 1. Between the bottom part 11 and the right side wall part 12, a concave bent part 13 bent at a substantially right angle is provided. Above the bent portion 13, other components of the manual sheet feeder 1 are arranged. The right side wall portion 12 of the base frame 10 is provided with an uneven portion 14 so as to face the upstream side in the paper supply direction. The concavo-convex portion 14 has a horizontal cross section in which a rectangular wave continues in the paper width direction (see FIGS. 4 and 5). The concavo-convex portion 14 meshes with the concavo-convex portion 23 provided at the downstream end of the push-up plate 20 and prevents paper from entering between the base frame 10 and the push-up plate 20.

  As shown in FIGS. 2 and 3, the push-up plate 20 is disposed substantially parallel to the bottom portion 11 above the bottom portion 11 and the bent portion 13 of the base frame 10. The paper is stacked on the upper surface of the push-up plate 20, and the push-up plate 20 particularly supports the downstream end portion of the paper. The push-up plate 20 includes two vertical side plates 21 provided on the front side and the rear side of the image forming apparatus. The push-up plate 20 is supported by the base frame 10 by a support portion 22 provided on the side plate 21, and is rotatable within a vertical plane parallel to the paper supply direction with the support portion 22 as the center and the downstream side as a free end. It is. A paper feed cam mechanism 40 is disposed in the vicinity of the side plate 21 provided on the rear side of the image forming apparatus of the push-up plate 20. The paper feed cam mechanism 40 will be described in detail later. The downstream end of the push-up plate 20 is close to the right side wall portion 12 of the base frame 10. The downstream end of the push-up plate 20 is provided with an uneven portion 23 that faces the downstream side in the paper supply direction and continues in the paper width direction (see FIG. 4). The uneven portion 23 meshes with the uneven portion 14 provided on the right side wall portion 12 of the base frame 10 described above.

  As shown in FIGS. 1 and 2, the paper feeding device 30 is provided on the downstream side of the push-up plate 20 in the paper supply direction. The sheet feeding device 30 separates and supplies the sheets one by one from the uppermost layer of the sheets stacked on the push-up plate 20. The paper feeding device 30 includes a paper feeding roller 31, a separation pad 32, and a conveyance guide 33.

  The paper feed roller 31 is supported on the base frame 10 by a support shaft 31a extending in the paper width direction. One paper feed roller 31 is provided at the center of the push-up plate 20 in the paper width direction. The paper feed roller 31 is rotated by a motor (not shown), contacts the uppermost layer of the paper stacked on the push-up plate 20, and feeds the paper to the image forming apparatus main body.

  The separation pad 32 has substantially the same width as that of the paper feed roller 31, and is provided at the central portion of the right side wall portion 12 of the base frame 10 in the paper width direction. The separation pad 32 is pivotally supported at the lower portion in FIG. 2 and is urged toward the paper feed roller 31 by urging means (not shown). The separation pad 32 is in contact with the surface of the paper opposite to the surface in contact with the paper feed roller 31. The separation pad 32 gives a high frictional force to the paper, and when the paper feeding by the paper feed roller 31 causes the phenomenon of double feeding in which the paper is overlapped, the lower lower paper is separated. To do. Note that the paper feed roller 31 has a greater frictional force against the paper than the separation pad 32.

  Two transport guides 33 are provided, one on each side of the paper feed roller 31 in the paper width direction. A guide surface 33a having a curved portion is formed on the transport guide 33 in order to smoothly feed the paper placed on the push-up plate 20 to the upper right (arrow D) in FIG. 2 (see FIG. 6). ). The conveyance guide 33 is attached so that the guide surface 33a faces the bottom 11 of the base frame 10 and the right side wall 12. Although the support guide 31a of the paper feed roller 31 passes through the transport guide 33, the transport guide 33 does not rotate even when the paper feed roller 31 rotates.

  A push-up plate urging means (not shown) is provided below the bottom surface of the push-up plate 20 and between the bottom portion 11 of the base frame 10. The push-up plate urging means is provided at a location that does not interfere with the arrangement of the paper detection device 50. The push-up plate urging means urges the push-up plate 20 toward a position where the uppermost layer of the paper on the push-up plate 20 contacts the paper feed roller 31. The push-up plate biasing means is composed of an elastic member such as a compression coil spring, a leaf spring, or rubber. A torsion coil spring may be attached to the support portion 22 of the push-up plate 20, and this may be used as the push-up plate urging means.

  As shown in FIGS. 1 and 3, the paper feed cam mechanism 40 is arranged at the downstream end of the push-up plate 20 at the end on the rear side of the image forming apparatus in the paper width direction. The paper feed cam mechanism 40 includes a paper feed cam 41 and a cam follower 42.

  In FIG. 3, the paper feed cam 41 is fixed to the support shaft 31 a of the paper feed roller 31 and is rotated together with the paper feed roller 31 by a motor (not shown). The cam follower 42 is provided on the upper surface of the downstream end of the push-up plate 20 and protrudes upward. The end face of the paper feed cam 41 is always in contact with the cam follower 42. The paper feed cam 41 has a position where the uppermost layer of the paper on the push-up plate 20 is in contact with the paper feed roller 31 each time the cross-sectional shape in the direction perpendicular to the axis of the support shaft 31a makes one rotation, and the paper feed roller 31 A shape is formed in which the push-up plate 20 is moved between the position 31 and a position separating a predetermined distance.

  The paper feed cam mechanism 40 normally pushes down the push-up plate 20 against the push-up plate urging means so that the uppermost layer of the paper on the push-up plate 20 does not contact the paper feed roller 31. When the paper is supplied, the paper feed cam mechanism 40 permits the push-up plate 20 to move to a position where the uppermost layer of the paper on the push-up plate 20 contacts the paper feed roller 31 for each paper.

  The detailed configuration of the sheet detection device 50 will be described with reference to FIGS. 4 to 7 in addition to FIGS. 4 is an enlarged perspective view showing the periphery of the manual paper feed unit similar to FIG. 1, showing a state in which the paper feed roller and the conveyance guide are removed, and FIG. 5 is an enlarged perspective view showing the paper detection device. 6 is a schematic vertical sectional front view showing a manual paper feed unit similar to FIG. 2 and shows a state cut by the paper detection device, and FIG. 7 shows a manual paper feed unit similar to FIG. A model vertical sectional front view shows a state where the actuator is rotated. FIG. 7 is a diagram in which the cutting position is shifted slightly rearward from FIG. 6.

  As shown in FIGS. 1 to 3, the sheet detection device 50 is provided below the push-up plate 20 and between the push-up plate 20 and the bottom portion 11 of the base frame 10. The paper detection device 50 is provided at the center of the bottom 11 in the paper width direction. The paper detection means 50 detects the presence or absence of the paper on the push-up plate 20 and whether or not the paper exists at a predetermined position. The paper detection device 50 includes an actuator 51, a sensor 52, and a support plate 53.

  As shown in FIGS. 5 and 6, the actuator 51 is provided in the bent portion 13 in the concave portion 14 a of the concave and convex portion 14 of the right side wall portion 12 of the base frame 10. The actuator 51 has a bell crank shape when viewed from the front side of the image forming apparatus, and includes a shaft portion 51a protruding at right angles on both sides at a corner portion of the bell crank. The actuator 51 rotates clockwise around the shaft portion 51a as shown in FIG. When the actuator 51 is disposed on the base frame 10, the movement of the actuator 51 in the axial direction is prevented by positioning the shaft portion 51a at the bent portion 13 in the recess 14a. The distance between both ends of the shaft 51a is slightly shorter than the width of the recess 14a.

  In addition, the actuator 51 includes a paper contact portion 51b where the paper contacts one end of the bell crank shape, and a sensor interference portion 51c used for displacement detection by the sensor 52 at the other end. The paper contact portion 51b extends upward from the shaft portion 51a. 3 and 4, the push-up plate 20 is provided with a notch 24 cut in the upstream direction at the downstream end in the sheet transport direction and at the position where the actuator 51 is provided. The sheet contact portion 51b protrudes upward from the top. The sensor interference part 51c extends from the shaft part 51a to the upstream side in the paper supply direction.

  As shown in FIGS. 5 to 7, the sensor 52 is provided in the vicinity of the sensor interference part 51 c of the actuator 51. The sensor 52 is configured by a transmissive optical sensor such as a photo interrupter, and includes a main body portion 52a, a light emitting portion 52b protruding from the main body portion 52a, and a light receiving portion 52c. In the sensor 52, the optical axis from the light emitting part 52b to the light receiving part 52c is parallel to the rotation axis of the actuator 51, and the direction in which the light emitting part 52b and the light receiving part 52c protrude from the main body part 52a is It is attached to the support plate 53 so as to be parallel to the upper surface of the bottom portion 11 constituting one surface of the bent portion 13. A sensor interference part 51 c of the actuator 51 appears and disappears in the optical path of the sensor 52.

  As shown in FIGS. 4 and 5, the support plate 53 that supports the sensor 52 is a plate-like sheet metal member that extends in the paper width direction, and is provided on the upper surface of the bottom 11 of the base frame 10. A sensor mounting portion 53 a is provided at a location corresponding to the position of the actuator 51 on the upstream side of the substantially central portion of the support plate 53 in the paper width direction. The sensor attachment portion 53 a is configured by a cut-and-raised portion that is perpendicular to the upper surface of the bottom portion 11. Accordingly, when the sensor 52 is attached to the sensor attachment portion 53a, the direction in which the light emitting portion 52b and the light receiving portion 52c protrude from the main body portion 52a of the sensor 52 is parallel to the upper surface of the bottom portion 11 of the base frame 10. Become.

  As shown in FIG. 5, an actuator support portion 53 b is provided at the downstream end of the portion of the support plate 53 corresponding to the position of the actuator 51. The actuator support portion 53b extends toward the back of the recess 14a of the base frame 10 where the actuator 51 is disposed. The tip of the actuator support portion 53b is bent so that the shaft portion 51a of the actuator 51 can be easily held. The bent portion has a stepped shape with a height corresponding to the diameter of the shaft portion 51 a so as not to hinder the rotation of the actuator 51. When the shaft 51a of the actuator 51 is positioned at the bent portion 13 in the recess 14a of the base frame 10 using such a support plate 53, and the support plate 53 is attached to the base frame 10, the actuator support 53b holds the shaft portion 51a from above and prevents escape from the bent portion 13 of the shaft portion 51a of the actuator 51.

  Thus, the base frame 10 which is a frame provided with the concave bent portion 13, the actuator 51 rotating around the shaft portion 51 a protruding on both sides, and the sensor 52 for detecting the displacement of the actuator 51, And a support plate 53 that is a support member of the sensor, the shaft 51a of the actuator 51 is positioned at the bent portion 13 of the base frame 10, and the support plate 53 is attached to the base frame 10, thereby Since the part 51 a is prevented from escaping from the bent part 13, a support member provided with a hole and protruding from the base frame 10 is not provided to support the actuator 51. And since the actuator 51 is supported only by attaching the support plate 53 to the base frame 10, the attachment of the actuator 51 is very simple. In this way, there is no need to worry about the occurrence of burrs or the attachment of a cramped shaft to the support member of the actuator 51. Therefore, it is possible to obtain a stable operation of the actuator 51 with a simple configuration in a small space.

  Further, the actuator 51 has a bell crank shape in a front surface perpendicular to the rotation axis, and includes a shaft portion 51a at a corner portion of the bell crank. Therefore, the shaft portion 51a of the actuator 51 is attached to the base frame 10. The actuator 51 is arranged so as to be along the surfaces on both sides of the bent portion 13 by being positioned in the concave bent portion 13. Therefore, since the actuator 51 can be disposed close to the base frame 10, further space saving can be achieved. Further, the paper contact portion 51b where the paper abuts on one end of the bell crank and the sensor interference portion 51c used for detecting displacement by the sensor 52 are provided on the other end. The minute displacement of 51b can be converted into a large displacement of the sensor interference unit 51c. Thereby, the sensitivity of the sensor 52 can be increased with respect to the contact of the sheet with the actuator 51, and the sheet can be detected with high accuracy.

  Further, since the sensor 52 is composed of a transmissive optical sensor, a transmissive optical sensor that is generally widely used as a sensor is employed, and paper detection can be performed with an inexpensive and simple configuration. .

  The sensor 52, which is a transmissive optical sensor, includes a main body 52a, a light emitting unit 52b protruding from the main body 52a, and a light receiving unit 52c. The optical axis of the transmissive optical sensor is the rotation of the actuator 51. A direction in which the light emitting part 52b and the light receiving part 52c protrude from the main body part 52a is parallel to the upper surface of the bottom part 11 constituting one surface of the bent part 13 of the base frame 10 while being parallel to the axis. Therefore, the sensor 52 can be disposed close to the base frame 10, and the area occupied by the sensor 52 can be reduced. Therefore, the actuator 51 can be disposed close to the base frame 10 and, in addition, space saving can be further increased.

  Further, in the present invention, since the paper detection device 50 is mounted on the paper supply device 1, it is possible to save space by a simple configuration without providing a support member having a hole that is difficult to form or attach a shaft. A high-performance sheet feeding device 1 that can obtain a stable operation of the actuator 51 can be obtained.

  Further, the paper feeding device 1 includes a base frame 10, a push-up plate 20 on which paper is stacked and rotatably supported by the base frame 10, a paper feeding device 30 that separates and supplies one sheet at a time from the uppermost layer of paper, The urging means for urging the push-up plate 20 toward the position where the uppermost layer of the sheet contacts the sheet feeding roller 31 of the sheet feeding device 30 and the position where the uppermost layer of the sheet contacts the sheet feeding roller 31 each time the sheet is supplied. The actuator 51 is provided below the push-up plate 20 and between the push-up plate 20 and the base frame 10. Thereby, the paper detection means 50 can be disposed in a very small space between the push-up plate 20 and the base frame 10. Accordingly, it is possible to prevent an increase in size of the paper feeding device 1 and to provide a more compact paper feeding device 1.

  Further, in the paper feeding device 1, the downstream end of the push-up plate 20 in the paper conveyance direction is close to the base frame 10, and an uneven portion that engages with each other is formed in each member at this close location. Then, since the actuator 51 is provided in the concave portion 14 a of the base frame 10, the concave and convex concave portion 14 a provided to prevent the paper from entering between the push-up plate 20 and the base frame 10 is used to make the paper A detection device 50 can be arranged. As a result, when the paper detection device 50 is arranged, a portion formed for a purpose different from the arrangement of the paper detection device 50 on the base frame 10 can be used, so that the space can be effectively used. . Further, as described above, since the actuator 51 is provided in the concave portion 14a of the base frame 10, the movement of the actuator 51 in the axial direction is prevented. Therefore, the position of the actuator 51 in the axial direction is not provided separately. Can be determined. Therefore, the number of parts and materials used can be reduced, and the cost of the sheet feeding device 1 can be reduced.

  Although the embodiment of the present invention has been described above, various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used in all devices that need to detect the presence or absence of a sheet and whether or not a sheet exists at a predetermined position in a sheet storage unit or a sheet conveyance path.

FIG. 4 is a perspective view showing a manual paper feed unit including a paper detection device according to an embodiment of the present invention and its periphery. FIG. 2 is a schematic vertical cross-sectional front view of the manual sheet feeder shown in FIG. 1. FIG. 4 is an enlarged perspective view showing the periphery of a manual paper feed unit similar to FIG. 1 and shows a state cut at a substantially central portion in the paper width direction perpendicular to the paper supply direction. FIG. 2 is an enlarged perspective view showing the periphery of a manual paper feed unit similar to FIG. 1 and shows a state where a paper feed roller and a conveyance guide are removed. FIG. 3 is an enlarged perspective view showing a paper detection device. Fig. 2 is a schematic vertical sectional front view showing a manual paper feed unit similar to Fig. 2 and shows a state cut at a portion of the paper detection device. Fig. 6 is a schematic vertical sectional front view showing a manual paper feed unit similar to Fig. 6 and shows a state in which the actuator is rotated.

Explanation of symbols

1 Manual paper feeder (paper feeder)
DESCRIPTION OF SYMBOLS 10 Base frame 11 Bottom part 12 Right side wall part 13 Bending part 14 Concave part 14a Concave part 20 Push-up plate 22 Support part 23 Concave part 24 Notch part 30 Paper feed device 40 Paper feed cam mechanism 41 Paper feed cam 42 Cam follower 50 Paper detection device 51 Actuator 51a Shaft part 51b Paper contact part 51c Sensor interference part 52 Sensor 52a Main body part 52b Light emitting part 52c Light receiving part 53 Support plate 53a Sensor mounting part 53b Actuator support part 100 Main body frame

Claims (7)

A frame provided with a concave bent portion, an actuator that projects shaft portions on both sides and rotates around the shaft portion by contact of paper, a sensor that detects displacement of the actuator, and a support member for the sensor And
The shaft detection unit is positioned at a bent portion of the frame, and the sensor support member is attached to the frame to prevent the shaft portion from escaping from the bent portion. apparatus.   In the actuator, the front shape perpendicular to the rotation axis is a bell crank shape, the shaft portion is at the corner of the bell crank, the paper abutting portion where the paper abuts at one end of the bell crank, and the other The sheet detecting apparatus according to claim 1, further comprising a sensor interference unit used for detecting displacement by the sensor at a tip of the sheet.   The sheet detection apparatus according to claim 1, wherein the sensor includes a transmissive optical sensor.   The transmissive optical sensor includes a main body portion, a light emitting portion projecting from the main body portion, and a light receiving portion. The optical axis of the transmissive optical sensor is parallel to the rotation axis of the actuator, and the main body portion. The paper detection device according to claim 3, wherein a direction in which the light emitting portion and the light receiving portion protrude from is parallel to a plane constituting one surface of the bent portion.   5. A paper feeding device comprising the paper detection device according to claim 1. A base frame, a paper stack, a push-up plate that is supported by the base frame so as to be rotatable in a vertical plane parallel to the paper supply direction, and a sheet separated from the top layer of the paper loaded on the push-up plate one by one A paper feeding device that urges the push-up plate toward a position where the uppermost layer of the paper on the push-up plate is in contact with a paper feed roller provided in the paper feed device, and the push-up is performed each time the paper is supplied. A paper feed cam mechanism that allows the push-up plate to move to a position where the uppermost layer of the paper on the board contacts the paper feed roller,
The frame of the paper detection device is the base frame that supports the push-up plate, and the actuator is provided below the push-up plate and between the push-up plate and the base frame. Item 6. The sheet feeding device according to Item 5.   The downstream end of the push-up plate in the paper transport direction is close to the base frame, and in this proximity, an uneven portion is formed on each member so that these members mesh with each other. The sheet feeding device according to claim 6, wherein the actuator is prevented from moving in an axial direction by providing the actuator.

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