JP2005102070A - Opening/closing detection mechanism and image forming apparatus adopting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely detect the opened/closed state of an opening/closing body while securing a reduction in cost by reducing the number of components with a simple structure. <P>SOLUTION: This opening/closing detection mechanism 30 detects whether an original pressing cover body 20 supported by a shaft turnably around a supporting shaft 106 provided at a top face side of a device main body 101 and extending horizontally closes the device main body 101, and is provided with a fulcrum shaft 45 parallel to a support axis 106, a member 40 to be detected supported by a shaft in a freely turnable way around the fulcrum shaft 45, and a detection member 50 for detecting an adjacent/separated state to/from the member 40 to be detected. In the member 40 to be detected, the moment of a light shielding board 44 side centering on the fulcrum shaft 45 and the moment of the other side are subjected to balance setting in the same manner. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an open / close detection mechanism for detecting an open / close state of an open / close body that is pivotally supported around a horizontal axis and an image forming apparatus to which this mechanism is applied.

  Conventionally, an open / close detection mechanism for detecting an open / closed state of an open / close body with respect to a device body as described in Patent Document 1 and Patent Document 2 is known. First, the open / close detection mechanism described in Patent Document 1 is applied to an electrophotographic printer apparatus, and a developing unit cover and a fixing unit cover serving as open / close bodies arranged in parallel are provided on the upper surface of the apparatus body. It has been. Each of these covers is supported in such a manner that each edge on the opposite side to each opposite edge is pivotable about a horizontal axis, and is rotated in the forward and reverse directions around each horizontal axis, so that the cover can be opened in the vertical direction. It can be opened and closed.

  An L-shaped lever is pivotally supported about the axis on the back side of the fixing unit cover, and an arm for rotating the lever on the back side of the developing unit cover. Is provided, and the arm presses the lever in a state where both covers are closed.

  On the other hand, a detector having a detection piece biased in the protruding direction is provided in the apparatus body, and the lever presses the detection piece in a state where both the fixing unit cover and the developing unit cover are closed. A detector detects the closing of both covers. Further, when any one of the covers is opened, the pressing state of the lever with respect to the detection piece is released by the rotation of the lever, thereby detecting that any one of the covers is opened. .

  The open / close detection mechanism described in Patent Document 2 is applied to a document pressing cover and an automatic document feeder of an image forming apparatus such as a copying machine, and a magnetic material is provided on the document pressing cover side as an opening / closing body. While the detection body consisting of a magnetic sensor is attached to the automatic document feeder side and the document presser cover is closed, the detected body magnetically acts on the detection body while the presser cover is attached. The closing can be detected. The detection result is notified to the user using a predetermined notification means.

Incidentally, the various opening / closing detection structures as described above are employed for detecting the opening / closing state of the document presser cover when, for example, the document presser cover is opened to read a thick document such as a book. This is to inform the user of the fact that the automatic document feeder cannot be used.
Japanese Utility Model Publication No. 8-2676 JP-A-10-304115

  By the way, in any of the open / close detection mechanisms described in Patent Documents 1 and 2, detection members must be provided on both the device main body and the open / close body attached to the device main body so as to be openable and closable. However, since a high degree of accuracy is required for the alignment of the two, there is a disadvantage that the assembling work becomes difficult and the assembling efficiency is lowered. In addition, even if the position of both detection members is ensured in the manufacturing stage, misalignment may occur between the two detection members due to repeated use of the device. May not be properly detected.

  In particular, in the case of the open / close detection mechanism described in Patent Document 1, there is a problem that the number of parts increases, for example, an urging means such as a spring for urging the detection piece is required. To do.

  Further, in the case of the open / close detection mechanism described in Patent Document 2, a magnetic sensor is used, but the magnetic sensor is expensive, and the use of such an expensive magnetic sensor increases the cost of the open / close detection mechanism. have.

  Therefore, a so-called self-orientation detection type in which a detected member that operates based on gravity according to the attitude of the sensor support is attached to a sensor support that includes a presence / absence sensor that detects the presence / absence of an object. Can be considered. The self-posture detection type open / close detection mechanism includes, for example, a self-detection member that comes close to or comes into contact with a predetermined sensor of the sensor support body in a state where the sensor support body is set in the upright posture. While detecting that the (sensor support) is upright, the detected member is separated from the sensor in a state where the sensor support is tilted, thereby detecting that the posture is set to the tilted posture. The one that is configured is adopted.

  If this self-position detection type opening / closing detection mechanism is attached to the document presser cover of the image forming apparatus, the open / close state of the document presser cover can be detected based on a detection signal from the sensor from the sensor support.

  However, in this open / close detection mechanism, the detection member (sensor support) and the detected member are combined to form a single integrated member, and the detection is performed according to the attitude of the sensor support itself. Since the members are detected or not detected, the mounting posture of the sensor support must be set precisely, and there is not only the inconvenience that the assembly work at the site becomes difficult and the workability is inferior. However, the movable range of the detected member must be narrow, and it is difficult to detect a slight open state of the document presser cover, so that the degree of freedom in design is reduced. Yes.

  The present invention has been made in view of the situation as described above, and can reliably detect the open / closed state of the opening / closing body while ensuring cost reduction by reducing the number of parts with a simple structure. It is an object of the present invention to provide an open / close detection mechanism that can be easily assembled and can increase design freedom, and an image forming apparatus to which this mechanism is applied.

  The invention (open / close detection mechanism) described in claim 1 is whether or not the open / close body pivotally supported around the horizontal axis provided on the upper surface side of the device main body is closed with respect to the device main body. An open / close detection mechanism for detecting a fulcrum shaft parallel to the horizontal axis, a detected member pivotally supported by the fulcrum shaft, and a state in which the detected member is close to the upper surface of the open / close body. A detection member for detection, and the detected member is pivotally supported around the fulcrum shaft in a state where one side and the other side are balanced with respect to the fulcrum shaft, and the detection member is The opening / closing body is shaped to detect a member to be detected at a predetermined opening / closing angle.

  According to a second aspect of the present invention (opening / closing detection mechanism), in the first aspect of the invention, the detected member always maintains a constant posture with respect to the side on which the cost detecting member is attached, while the detecting member Is characterized in that the posture changes with respect to the side on which the detection member is attached.

  According to a third aspect of the present invention (opening / closing detection mechanism), in the first or second aspect of the invention, the detection member has a recess serving as a receiving portion of the detected member, and the detected member has one side on one side. It is formed in the shape of a flat plate that can be received between the opposing walls of the recess, and the other side is formed by a weight extending downward.

  According to a fourth aspect of the present invention (opening / closing detection mechanism), in the invention according to any one of the first to third aspects, the detection member and the detected member are formed separately from each other. It is characterized by.

  According to a fifth aspect of the present invention (image forming apparatus), the open / close detection mechanism according to any one of the first to fourth aspects is applied to a document presser lid.

  According to the first aspect of the present invention (open / close detection mechanism), since the member to be detected is pivotally supported around the fulcrum shaft, the open / close body is rotated about the horizontal axis by the open / close operation. Rotating relative to the fulcrum shaft with respect to the opening / closing body while maintaining an absolute posture, and detecting the opening / closing state of the opening / closing body based on whether or not the detected member is close to the detection member can do.

  Since both the detection member and the detected member are provided on the opening / closing body, the conventional detection member is provided on either the opening / closing body or the device main body, and the detected member is provided on the other side. Compared to the above, it is easy to align the detection member and the member to be detected, which can contribute to a reduction in assembly cost.

  Moreover, the conventional inconvenience that the detection member is misaligned due to repeated use of the device, which makes it difficult to properly detect the open / closed state, can be solved.

  According to the invention described in claim 2 (opening / closing detection mechanism), the detected member always maintains a fixed posture with respect to the side to which the member is attached, while the detecting member has a posture with respect to the side to which the member is attached. Therefore, the structure provided with the detecting means only on the opening / closing body side can be realized with a simpler structure.

  According to the invention described in claim 3 (open / close detection mechanism), the member to be detected is formed in a flat plate shape that can be sandwiched between the opposing walls of the concave portion of the member to be detected, and the other side is a weight that extends downward. Since the weight is formed by the weight, the weight is suspended on the fulcrum shaft (so-called Yajirobei state), and the posture supported by the fulcrum shaft of the detected member is thereby changed regardless of the opening of the opening / closing body. It can be made extremely stable.

  Then, for example, by providing a light emitting element on one facing surface of the recess of the detection member and providing a light receiving element on the other facing surface to constitute an optical sensor, the detected member is in mechanical contact with the detection member. It is possible to detect whether or not the opening / closing body is in a closed state by simply fitting between the opposing surfaces of the recess without being close to each other and blocking the optical path between the light emitting element and the light receiving element. Since there is no contact, the frequency of failures can be greatly reduced, which can contribute to a reduction in running costs.

  According to the invention described in claim 4 (open / close detection mechanism), since the detection member and the detected member are formed as separate bodies independent of each other, the detection member is adapted to the structure and mounting position of the open / close body. It becomes possible to attach the detection member to the opening / closing body, making the construction on site easy, and appropriately setting the shape and size of the detection member or detection member according to the model of the device body Therefore, it is possible to increase versatility by increasing variations, and as a result, the degree of freedom in design can be increased. In particular, when the length dimension of the member to be detected is increased, the detection power can be increased.

  Then, by adopting a commercially available general-purpose product using, for example, an optical sensor as the detection member, it becomes possible to cope by designing only the shape and size of the detected member, and a cost reduction is secured. Can increase variations.

  That is, according to the open / close detection mechanism according to claim 4, it is possible to contribute to the reduction of the number of parts with a simple structure, and to ensure the open / closed state of the open / close body while ensuring the cost reduction of the manufacturing cost. It is possible to detect, and in addition, it is possible to improve the workability of on-site construction and improve the degree of freedom of design. Can do.

  According to the invention (image forming apparatus) described in claim 5, by applying the opening / closing detection mechanism described in claim 1 or 2 to the document pressing cover, the opening / closing detection of the document pressing cover can be reliably performed at low cost. Is possible.

  FIG. 1 is a side sectional view showing an embodiment of an image forming apparatus to which an open / close detection mechanism according to the present invention is applied. The image forming apparatus 10 is configured to read an original image of the original P1, transfer the read image onto the paper P2, and discharge the paper P2 onto which the image has been transferred, in order to read the original image. An original document feeder 11 for placing the original document P1, an image reading unit 12 for reading a document image from the document document P1 placed on the automatic document feeder 11, and an original document read by the image reading unit 12 An image forming unit 13 that transfers an image as a toner image onto a sheet P2, a fixing unit 14 that fixes a toner image on the sheet transferred by the image forming unit 13, and a sheet P2 that is fed toward the image forming unit 13. Is formed by being mounted on a device main body (equipment main body) 101 having a box shape.

  The automatic document feeder 11 includes an openable / closable document press cover body (open / close body) 20 and a contact glass 29 fitted in a rectangular opening at the center of the upper surface of the apparatus main body 101. A document tray 21 is formed at the center of the upper surface of the document pressing cover body 20. The document tray 21 is used when a plurality of documents P1 are placed in a stacked state and document images of the documents P1 are continuously read. An automatic document feeder 22 is provided on one side of the document tray 21 (on the left side in FIG. 1) to feed out one by one from the bundle of placed documents P1 toward the contact glass 29. ing. The document P 1 after the image is read on the contact glass 29 by the automatic document feeder 22 is discharged onto a discharge tray 23 provided at the lower portion of the document tray 21.

  Further, the document pressing cover body 20 is attached to the apparatus main body 101 so as to be rotated around a support shaft 106 (FIG. 2) described later and to be opened and closed with respect to the contact glass 29. When the original P1 is manually fed to the contact glass 29 one by one or when the original P1 is a book-like one, the original pressing cover body 20 is opened and the original P1 is placed on the contact glass 29. Then, the image reading unit 12 reads an image with the document pressing cover body 20 closed so as to overlap the document P1.

  The image reading unit 12 includes an optical system unit 120 that scans a document image that is in close contact with the contact glass 29. The optical system unit 120 includes a moving light source 121 that irradiates light on a document image while moving, and a plurality of mirrors that reflect reflected light on the document image of light from the moving light source 121 along a predetermined optical path. 122, a lens member 123 for converging the light in the optical path, and the like.

  Then, the moving light source 121 moves parallel to the contact glass 29 and the reflected light of the light irradiated on the document surface is input to the CCD 124 via the mirror 122 and the lens member 123 so that the document image is sequentially scanned. It has become. Screen information consisting of analog amounts obtained by such scanning is converted into digital signals one by one by the CCD 124 and then temporarily stored in a storage device (not shown), and directed from the laser beam transmitter 133 to the image forming unit 13 as necessary. The laser light is output in the state.

  The image forming unit 13 includes a photosensitive drum 131 on which an electrostatic image and a toner image are sequentially formed on the peripheral surface, and a conveyance belt 132 that feeds the paper P2 to the peripheral surface of the photosensitive drum 131. Yes. A laser beam having image information obtained by scanning the original image of the original P1 is irradiated from the laser light transmitter 133 to the peripheral surface of the photosensitive drum 131 rotating around the axis, and thereby the photosensitive drum 131 is exposed to light. An electrostatic image is sequentially formed on the peripheral surface of the photosensitive drum 131, and toner is supplied from the developing unit 134 to the electrostatic image on the downstream side of the scanning light irradiation position, whereby the toner image is formed on the peripheral surface of the photosensitive drum 131. Is to be formed. The toner image is transferred to the paper P2 fed by the transport belt 132.

  The fixing unit 14 performs a fixing process on the transfer image on the paper P2 onto which the image is transferred by the photosensitive drum 131 in the image forming unit 13, and has a heating member such as an energizing heating element mounted therein. It has a roller 141 and a pressure roller 142 disposed at the lower part so as to face the fixing roller 141. Then, the paper P2 led out from the image forming unit 13 as the conveyance belt 132 is driven to rotate is fed between the fixing roller 141 and the pressure roller 142, and is heated by the fixing roller 141, thereby toner. The image is fixed on the paper P2. The sheet P2 that has passed through the fixing unit 14 is carried out of the system via a pair of carry-out rollers 143 provided at the most downstream end.

  The paper storage unit 15 includes a plurality of paper cassettes 151 that are detachably mounted in the apparatus main body 101. Each paper cassette 151 is provided with a pickup roller 152, a paper feed roller 153, and the like at one end (right end in the example shown in FIG. 1), and is loaded into the paper cassette 151 by driving rotation of the pickup roller 152. The uppermost one of the bundle of sheets P2 is sequentially fed out and led out toward the conveyance path 102 via the sheet feeding roller 153.

  Then, the paper P2 led out from the paper cassette 151 via the pickup roller 152 and the paper feed roller 153 is conveyed by the conveyor belt 132 while the toner image on the peripheral surface of the photosensitive drum 131 is transferred, and the fixing unit 14 continues. After the heat fixing process is performed by the fixing roller 141, the fixing roller 141 passes through the carry-out roller pair 143 and is discharged to the outside from the discharge port of the apparatus main body 101.

  A power switch 103 is provided at an appropriate position on the side surface of the apparatus main body 101, and a start button 104 is provided at an appropriate position on the upper surface of the apparatus main body 101. When the power switch 103 is switched on, the start button 104 is pressed. Thus, the automatic document feeder 11, image reading unit 12, image forming unit 13, fixing unit 14 and paper storage unit 15 operate with their respective functions, whereby the image P1 image is transferred to the paper P2. It has become so.

  In the present embodiment, a paper reversing unit 16 is interposed between the fixing unit 14 and the paper storage unit 15. The paper reversing unit 16 is used when the double-sided printing process is performed on the paper P2, and the paper P2 that has been subjected to the fixing process on the first surface by the fixing unit 14 is once introduced into the paper reversing unit 16. Here, after the reversal process (reversing process) is performed, the sheet is returned to the image forming unit 13, and after the second surface transfer process in the image forming unit 13 and the fixing process in the fixing unit 14 are executed, the paper discharge port The paper is discharged through the.

  The open / close detection mechanism 30 according to the present invention is attached to the back side of the cover lid (open / close body) 111 as described above (the portion corresponding to the back side of the paper surface of FIG. 1). 2 and 3 are partially cutaway perspective views of the image forming apparatus 10 showing the mounted state of the open / close detection mechanism 30 as seen from the back side, and FIG. 2 shows a state in which the document pressing cover body 20 is opened. FIG. 3 shows a state where the document presser cover body 20 is closed. FIG. 4 is a partially enlarged perspective view showing a state where the open / close detection mechanism 30 is mounted on the deck portion 25 of the document pressing cover body 20. 2 to 4, the XX direction is referred to as the width direction, and the YY direction is referred to as the front-rear direction. In particular, the -X direction is leftward, the + X direction is rightward, the -Y direction is forward, and the + Y direction is forward. It is called the back.

  As shown in FIGS. 2 and 3, the document pressing cover body 20 has a bottom plate 24 as a structural material facing the contact glass 29 at the center, and the document tray 21 and the automatic document feeder 22 ( 1) and the paper discharge tray 23 are supported by the bottom plate 24. At the left position of the bottom plate 24, a deck portion 25 is formed on which various gear mechanisms for driving the automatic document feeder 22 and electronic components are mounted. The deck unit 25 is covered with a deck-side blind cover 251, and the automatic document feeder 22 is covered with a feeder-side blind cover 221, and these covers 251 and 221 cover the upper surface of the document pressing cover body 20. Has become beautiful.

  A pair of front and rear direction brackets 105 projecting upward from the upper edge portion is provided on the back surface (left surface) side of the apparatus main body 101. The left edge portion of the deck portion 25 of the bottom plate 24 is connected to the bracket 105 via a support shaft (horizontal shaft) 106, whereby the document pressing cover body 20 rotates forward and backward around the support shaft (horizontal shaft) 106. The posture can be changed between the open posture shown in FIG. 2 and the closed posture shown in FIG.

  A shelf plate 252 and a weir member 253 having a U-shape in cross-sectional view are provided adjacent to the shelf plate 252 and extending in the front-rear direction at a substantially central position in the front-rear direction of the deck portion 25. The open / close detection mechanism 30 according to the invention is provided across the shelf plate 252 and the weir member 253.

  FIG. 5 is an exploded perspective view showing an embodiment of the open / close detection mechanism 30, and FIG. 6 is an assembled perspective view thereof. In addition, about the direction display by X and Y in FIG. 5 and FIG. 6, it is the same as that of the case of FIG. As shown in these drawings, the open / close detection mechanism 30 includes a detected member 40 that is detachably attached to a weir member 253 (FIG. 4) of the deck portion 25 of the document presser cover body 20, and the detected member 40. Correspondingly, a detection member 50 fixed to the shelf plate 252 (FIG. 4) of the deck unit 25 is provided.

  The detected member 40 includes a detected member main body 41 having an L-shape when viewed from the side, and a fulcrum shaft 45 in sliding contact with the central portion of the detected member main body 41. The fulcrum shaft 45 includes a cylindrical shaft main body 46 and a pair of D-cut cylindrical bodies 47 that are concentrically provided from both end faces of the shaft main body 46. A part of the peripheral surface of the D-cut columnar body 47 is provided with a D-cut surface 471 extending in the longitudinal direction.

  The detected member main body 41 includes a prismatic fulcrum shaft holding portion 42 through which the fulcrum shaft 45 penetrates, and a weight portion 43 extending from the right end portion of the fulcrum shaft holding portion 42 toward the lower right. , And a light shielding plate 44 extending leftward from the left end of the fulcrum shaft holding portion 42. A cylindrical body 421 extending in the front-rear direction perpendicular to the direction in which the fulcrum shaft holding portion 42 extends is formed at an appropriate position of the fulcrum shaft holding portion 42. The inner diameter dimension of the cylindrical body 421 is set to be slightly smaller than the outer diameter dimension of the shaft main body 46 of the fulcrum shaft 45, so that the two are mutually fitted in the state where the shaft main body 46 is fitted inside the cylindrical body 421. The shaft body 46 can rotate around the axis.

  The weight portion 43 is formed by extending in a circular arc from the right end portion of the fulcrum shaft holding portion 42 to the right shoulder downward, and then extending linearly downward from the lower end surface thereof. ing. By adopting such a shape, the weight portion 43 can secure a weight that can function as a weight.

  The light shielding plate 44 is formed in a flat shape so that the thickness dimension in the front-rear direction is reduced, and can effectively shield light traveling in the front-rear direction by spreading in the width direction and the vertical direction.

FIG. 7 is an explanatory diagram for explaining the weight balance between the weight 43 side and the light shielding plate 44 side with the fulcrum shaft 45 as a boundary. In the present invention, as shown in FIG. 7, the axis of the fulcrum shaft 45 is “O”, and the weight and the gravity center position on the side of the weight 43 with the axis O as the boundary are “W1” and “G1”, respectively. The weight and the center of gravity position are set to “W2” and “G2” on the light shielding plate 44 side with respect to the axis O, respectively, and the length of the perpendicular line dropped from the axis O to the vertical line passing through the center of gravity G1. “L1” is the length of the vertical line drawn from the axis O to the vertical line passing through the center of gravity G2, and “L2” (in the example shown in FIG. The detected member main body 41 is expressed by the following equation (1), that is,
L1 × W1 = L2 × W2 (1)
The shape and weight are set to satisfy

  Further, the center of gravity of the detected member 40 is set such that the entire center of gravity of the detected member 40 is positioned on a perpendicular line that is lowered from the axis O to the horizontal plane in a state where the detected member main body 41 is positioned at the close position.

  This is because when the detected member main body 41 has the same clockwise and counterclockwise moments about the axis O of the fulcrum shaft 45 and the detected member main body 41 is tilted around the axis O, Since a moment toward the restoring direction acts, the horizontal posture of the light shielding plate 44 is maintained regardless of the open / close state of the document pressing cover body 20.

  As shown in FIG. 4, the detected member 40 includes a weight portion including a fulcrum shaft 45 in a notch portion 254 formed by notching the left side of the weir member 253 of the document pressing cover body 20. The light shielding plate 44 is mounted on the weir member 253 in a state where the light shielding plate 44 protrudes leftward from the notch 254.

  Partition walls 255 are respectively provided at front and rear positions of the notch portion 254 in the weir member 253, and a notch groove 256 formed by being cut downward from the upper edge portion of each partition wall 255. By fitting the D-cut cylindrical body 47 of the fulcrum shaft 45 into these cut grooves 256, the detected member 40 is mounted on the notch portion 254 of the weir member 253 with the fulcrum shaft 45 being prevented from rotating. It is like that.

  In a state where the detected member 40 is mounted on the notch 254 of the dam member 253, the detected member main body 41 is rotatable around the shaft main body 46 (FIG. 6) of the fulcrum shaft 45. .

  As shown in FIG. 5, the detection member 50 includes a bifurcated body (a member for forming a recess according to the present invention) 51 having an open top, and an optical sensor 54 attached to the bifurcated body 51. It is configured. The bifurcated body 51 stands from a horizontal bar 52 that is fixed to the shelf plate 252 (FIG. 4) of the document presser cover body 20 by screwing or the like while extending in the front-rear direction, and from the front and rear ends of the horizontal bar 52. It is composed of a pair of standing arms 53 provided in the front-rear direction. A recess capable of receiving the light shielding plate 44 according to the present invention is formed between the pair of standing arms 53. As shown in FIG. 3, the bifurcated body 51 is configured such that the light shielding plate 44 of the detected member main body 41 is positioned between the pair of standing arms 53 in a state where the document pressing cover body 20 is set to the closed posture. The installation position is set as follows.

  The light sensor 54 includes a light emitting element 55 mounted on the inner surface side of one standing arm 53, and a light receiving element 56 mounted on the inner surface side of the other standing arm 53 so as to face the light emitting element 55. It is made up of. When the light emitted from the light emitting element 55 is received by the light receiving element 56, the received light is converted into an electric signal.

  Therefore, as shown in FIG. 2, when the document pressing cover body 20 is set to the open posture, and thus the light shielding plate 44 of the detection member 40 is detached from between the pair of standing arms 53 of the detection member 50. Since the light emitted from the light emitting element 55 is received by the light receiving element 56 and converted into an electric signal, it is possible to detect that the document pressing cover body 20 is opened by the electric signal.

  On the other hand, as shown in FIG. 3, when the document presser cover body 20 is set to the closed posture, the light shielding plate 44 of the detected member main body 41 is fitted between the pair of standing arms 53 and the light shielding is performed. Since the light from the light emitting element 55 is not incident on the light receiving element 56 due to the light shielding by the plate 44, the electric signal is not output from the light receiving element 56, whereby the document pressing cover body 20 is set to the closed posture. This can be detected.

  8A and 8B are explanatory views for explaining the operation of the open / close detection mechanism of the present invention. FIG. 8A is a state in which the document presser cover body 20 is set to a fully open position, and FIG. 8B is a document presser cover. A state in which the body 20 is between the fully open position and the fully closed position, and (C) indicate a state in which the document presser cover body 20 is set to the fully closed position. In FIG. 8, since the document pressing cover body 20 is schematically shown, the dimensions do not coincide with the previous drawings.

  First, in the state shown in FIG. 8A, the original press cover body 20 is completely opened, and the angle (opening / closing angle) formed between the original pressing cover body 20 and the horizontal surface is steep, approximately 60 °. The detected member 40 does not change its absolute posture with respect to the horizontal plane by rotating relative to the document pressing cover body 20 about the fulcrum shaft 45, and therefore the detection member 50 is detached from the bifurcated body 51 of the detection member 50. It has become. In this state, since the light from the light emitting element 55 of the optical sensor 54 disposed opposite to the pair of standing arms 53 of the bifurcated body 51 is received by the light receiving element 56, the document presser cover body 20 is in an open state. Is detected.

  Next, when the document pressing cover body 20 is rotated clockwise around the support shaft 106 starting from the state shown in FIG. 8A, the angle of the document pressing cover body 20 with respect to the horizontal plane is as shown in FIG. As shown in (b), the inclination angle gradually decreases and the inclination angle becomes gentle. However, the detected member 40 has a fulcrum shaft 45 with respect to the document pressing cover body 20 without changing the absolute posture. The light shielding plate 44 is gradually moved closer to the bifurcated body 51 due to the relative rotation in the counterclockwise direction.

  When the document pressing cover body 20 is closed, the light shielding plate 44 of the detected member 40 is between the pair of standing arms 53 of the bifurcated body 51 of the document pressing cover body 20 as shown in FIG. Therefore, the light from the light emitting element 55 is shielded by the light shielding plate 44 and does not reach the light receiving element 56, so that it is detected that the document pressing cover body 20 is closed. Even when the document holding cover body 20 is closed and the angle with respect to the horizontal plane does not become “0”, the document pressing cover body is set by the detection member 50 by appropriately setting the mounting position and orientation of the detection member 50. 20 closed states can be detected.

  When the document presser cover body 20 set in the closed position is opened, the detected member 40 follows the above order in the reverse order and is relatively clockwise around the fulcrum shaft 45 with respect to the document presser cover body 20. Since it rotates and disengages from the bifurcated body 51, the light receiving element 56 that has not received light until now receives light from the light emitting element 55, thereby detecting that the document pressing cover body 20 is opened. The

  As described above in detail, the open / close detection mechanism 30 according to the present invention includes the document pressing cover body 20 that is pivotally supported around the support shaft 106 that is provided on the upper surface side of the apparatus main body 101 and extends in the lateral direction. The apparatus body 101 detects whether or not the apparatus main body 101 is closed. A fulcrum shaft 45 parallel to the support shaft 106 is provided on the upper surface side of the document pressing cover body 20, and the fulcrum shaft 45 is rotatable. And a detection member 50 for detecting the proximity / separation state of the detection member 40. The detection member 40 is provided on one side (light shielding) with the fulcrum shaft 45 as a boundary. Since the plate 44 side and the other side (the weight part 43 side) are balanced, the document pressing cover body 20 is opened and closed as the detected member 40 is pivotally supported around the fulcrum shaft 45. When it is rotated around the support shaft 106 by operation, In this state, the document pressing cover body 20 is rotated relative to the document pressing cover body 20 around the fulcrum shaft 45, and the document pressing cover body 20 is closed by the proximity and separation of the detected member 40 to the detection member 50. It can be detected whether or not.

  Since both the detection member 50 and the detected member 40 are provided on the document pressing cover body 20, the conventional detection member 50 is provided on either the document pressing cover body 20 or the apparatus main body 101, and Compared with the case where the member 40 to be detected is provided on the other side, the alignment between the detection member 50 and the member 40 to be detected is easy, and it is possible to contribute to a reduction in assembly cost.

  Moreover, the conventional inconvenience that the detection member is misaligned due to repeated use of the device, which makes it difficult to properly detect the open / closed state, can be solved.

  In addition, since the detection member 50 and the detected member 40 are formed separately from each other, the detection member 50 and the detected member 40 are arranged in accordance with the structure and mounting position of the document pressing cover body 20. It is possible to attach to the document presser cover body 20, and the construction at the site becomes easy, and the shape and size of the detection member 50 or the detected member 40 can be appropriately set according to the model of the device main body. Therefore, it is possible to increase versatility by increasing variations, and as a result, the degree of freedom in design can be increased. In particular, when the length of the detected member 40 is increased, the detection power can be increased.

  And, by adopting a commercially available general-purpose product using, for example, an optical sensor as the detection member 50, it becomes possible to cope by designing only the shape and size of the detected member 40, thereby ensuring cost reduction. In addition, the variation can be increased.

  That is, according to the opening / closing detection mechanism 30 according to the present invention, it is possible to contribute to the reduction of the number of parts with a simple structure, and while ensuring the cost reduction of the manufacturing cost due to this, the opening / closing state of the document presser cover body 20 Thus, it is possible to obtain an excellent effect that could not be achieved by the conventional opening / closing detection mechanism that can be reliably detected.

  The detection member 50 has a bifurcated body 51 that can sandwich the member 40 to be detected in a separated state, and a light emitting element 55 is provided on the opposing surface of one standing arm 53 of the bifurcated body 51. Since the light receiving element 56 is provided on the opposite surface of the other standing arm 53, the pair of standing arms 53 of the bifurcated body 51 is simply brought close to the detected member 40 without mechanically contacting the detecting member 50. It is possible to detect whether or not the document presser cover body 20 is in a closed state by fitting in between and blocking the optical path between the light emitting element 55 and the light receiving element 56, and there is no mechanical contact. Can be significantly reduced, which can contribute to a reduction in running cost.

  The detected member 40 has a light shielding plate 44 formed in a flat plate shape that can be sandwiched between both arms of the bifurcated body 51 on one side of the fulcrum shaft 45, and the other side. Since the weight portion 43 extending downward is formed on the side, the weight portion 43 is suspended from the fulcrum shaft 45 and is thereby supported by the fulcrum shaft 45 of the detected member. Can be made extremely stable regardless of the opening degree of the document presser cover body 20.

  The present invention is not limited to the above embodiment, and includes the following contents.

  (1) In the above embodiment, the light shielding plate 44 of the detection member 40 is fitted between the pair of standing arms 53 of the detection member 50 when the document pressing cover body 20 is closed. However, instead of this, the light shielding plate 44 may be fitted between the standing arms 53 when the document pressing cover body 20 is opened.

  (2) In the above embodiment, the detected member main body 41 of the detected member 40 is pivotally supported around the fulcrum shaft 45, while the bifurcated body 51 of the detecting member 50 is the document pressing cover body 20. However, the light-shielding plate of the member to be detected may be fixed to the document pressing cover body 20 while the detection member side is pivotally supported around the fulcrum shaft.

  (3) In the above embodiment, the optical sensor 54 is employed as the detection member 50 that detects the proximity of the light shielding plate 44 of the detected member main body 41, but the present invention is used for the detection member 50. The sensor is not limited to the optical sensor 54, and various proximity sensors such as a magnetic sensor can be employed.

  (4) In the above-described embodiment, the bifurcated body 51 is employed as a concave portion that can receive the light shielding plate 44. However, in the present invention, the bifurcated body 51 forms the concave portion. The present invention is not limited to this, and the light emitting element 55 may be formed anywhere as long as the light emitting element 55 can be mounted on one of the opposing surfaces and the light receiving element 56 can be mounted on the other.

It is explanatory drawing of side sectional drawing which shows one Embodiment of the image forming apparatus with which the opening-and-closing detection mechanism concerning this invention was applied. FIG. 5 is a partially cutaway perspective view of the image forming apparatus showing the mounting state of the open / close detection mechanism as seen from the back side, showing a state in which the document pressing cover body is opened. FIG. 4 is a partially cutaway perspective view of the image forming apparatus showing a mounting state of the open / close detection mechanism as viewed from the back side, and shows a state where the document pressing cover body is closed. FIG. 5 is a partially enlarged perspective view showing a state in which the open / close detection mechanism is mounted on the deck portion of the document presser cover body. It is a disassembled perspective view which shows one Embodiment of an opening / closing detection mechanism. FIG. 6 is an assembled perspective view of the open / close detection mechanism shown in FIG. 5. It is explanatory drawing for demonstrating the weight balance of the weight part side and the light-shielding board side on the fulcrum axis | shaft as a boundary. 4A and 4B are explanatory diagrams for explaining the operation of the open / close detection mechanism of the present invention, in which FIG. 4A is a state where the document presser cover body is set to a fully open posture, and FIG. A state between the fully closed postures (c) indicates a state in which the document presser cover body is set to the fully closed posture.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 101 Main body 102 Carriage path 103 Power switch 104 Start button 105 Bracket 106 Support axis (horizontal axis) 11 Automatic document feeder 12 Image reading unit 120 Optical system unit 121 Moving light source 122 Mirror 123 Lens member 124 CCD
DESCRIPTION OF SYMBOLS 13 Image forming part 131 Photosensitive drum 132 Conveying belt 133 Laser beam transmitter 134 Developing part 141 Fixing roller 142 Pressure roller 143 Unloading roller pair 151 Paper cassette 152 Pickup roller 153 Paper feeding roller 20 Document pressing cover body (opening / closing body)
21 Document tray 22 Automatic document feeder 221 Feeder side blind cover 23 Paper discharge tray 24 Bottom plate 25 Deck portion 251 Deck side blind cover 252 Shelf plate 253 Weir member 254 Notch portion 256 Cut groove 30 Open / close detection mechanism 40 Detected member 41 Detected member main body 42 fulcrum shaft holding portion 43 weight portion 44 light shielding plate 45 fulcrum shaft 46 shaft main body 47 D-cut columnar body 50 detecting member 51 bifurcated body (concave portion) 52 horizontal arm 53 standing arm 54 photosensor 55 light emitting element 56 Light receiving element

Claims (5)

An opening / closing detection mechanism for detecting whether the opening / closing body pivotally supported around the horizontal axis provided on the upper surface side of the device body is in a closed state with respect to the device body,
A fulcrum shaft that is parallel to the horizontal axis, a detected member that is pivotally supported by the fulcrum shaft, and a detection member that detects the proximity of the detected member are provided on the upper surface of the opening / closing body.
The detected member is pivotably supported around the fulcrum shaft in a state where one side and the other side are balanced with respect to the fulcrum shaft,
The detection member is characterized in that the opening / closing body is shaped to detect the member to be detected at a predetermined opening / closing angle.   The detected member always maintains a constant posture with respect to the side where the cost detecting member is attached, while the detecting member changes its posture with respect to the side where the detecting member is attached. The opening / closing detection mechanism according to claim 1.   The detection member has a recess serving as a receiving portion of the detected member, and the detected member is formed in a flat plate shape that can be received between opposing walls of the recess, and the other side is downward. The opening / closing detection mechanism according to claim 1, wherein the opening / closing detection mechanism is formed by a weight extending toward the front.   The open / close detection mechanism according to claim 1, wherein the detection member and the member to be detected are formed separately from each other. 5. An image forming apparatus, wherein the open / close detection mechanism according to claim 1 is applied to an original cover.