JP4941667B2 - Image reading device - Google Patents

Description

  The present invention relates to a so-called flatbed scanner type image reading apparatus in which an original is placed on a placement surface of an original table and the original is read while moving an image reading means.

  Conventionally, as an image reading device mounted on a copying machine, a scanner device, or a multi-function device equipped with these functions, an image reading means such as a CCD (Charge Coupled Devices) is moved on a document stationary on a platen. There are a flatbed scanner type that reads while reading, and an automatic document feeder (ADF) type that reads the document while passing the document so as to pass through a position facing the stationary image reading means.

  Since the image reading apparatus performs any of the same size, enlargement, and reduction based on the size of the original and records the image on the corresponding size of recording paper, it is necessary to correctly detect the original size. As a method for correctly detecting the document size, in the automatic document transport mechanism type, a sensor provided in the transport path detects the document size by reading the difference in passage time between the leading edge and the trailing edge of the document. On the other hand, in a type in which an original is placed on a platen as a flatbed scanner and read, the image reading unit performs preliminary scanning (preliminary scanning) before scanning (main scanning) for reading the contents of the original. For example, a method for detecting the size of a document is known.

By the way, generally, as described in Patent Document 1 or the like, an openable / closable lid is attached to the document table so that the document is pressed against the document table inside the lid. The presser member is provided.
Japanese Patent Laid-Open No. 3-34765

  Normally, white paper is often used for the original. Therefore, if the original is pressed with a white presser member, the border between the original and the presser member is determined when the size of the original is read during preliminary scanning. There is a problem that it is difficult to accurately grasp the size of the manuscript. For this reason, there is a case in which the pressing member is colored in black or the like different from white to clarify the boundary line between the document and the pressing member.

  However, as described in “Prior Art” of Patent Document 1, if the press member colored in black is in close contact with the document, the press member is also read when the document is read in the main scanning. However, since the periphery of the document may be read as an image with a black border, the content of the document cannot be read correctly.

  The present invention solves the above-described problem, and accurately detects the document size even when the pressing member for pressing the document is colored white when reading the size of the document placed on the document table. An object of the present invention is to realize an image reading apparatus capable of performing the above.

In order to achieve the above object, an image reading apparatus according to a first aspect of the present invention includes a document table having a placement surface on which a document is placed and a peripheral portion surrounding the placement surface, and the above-described placement on the document table. there the image reading apparatus comprising an image reading means for reading an original while moving is disposed on the opposite side surface, and a lid for opening and closing the mounting surface side with respect to the platen not covered prior to said platen A pressing member provided on a surface of the lid on the platen side, which presses the document placed on the placement surface, a cam unit that is displaced by the movement of the image reading unit, and a cam unit. A cam surface that contacts the pressing member and moves the pressing member in contact with and away from the mounting surface; and a control unit that controls the operation of the image reading unit. Pre-scanning that detects the size of the document by the image reading means And over de, said has a present scan mode for reading a document by the image reading unit, in the preliminary scan mode, the by cam means, at least the site is the placement of the pressing member facing the image reading means spaced apart from the surface, the present scan mode, the pressing member by the cam means is one which approaches the said mounting face.

  According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the presser member is a flat plate-like member facing the placement surface, and the entire presser member is the spare member. In the scanning mode, it is separated from the placement surface, and in the main scanning mode, it approaches the placement surface.

According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect , the cam means is disposed on the opposite side of the placement surface on the document table, and the cam surface is formed on the peripheral portion. Through the hole formed in the hole, the protrusion comes into contact with the pressing member side.

According to a fourth aspect of the present invention, in the image reading apparatus according to the third aspect , the cam means has a contact portion that contacts the image reading means, and the contact portion is the image reading device. The means is disposed outside a moving range that moves when performing the main scanning mode, and moves the image reading means to a position where it abuts the abutting portion when the cam means is displaced. .

According to the first aspect of the present invention, since the cam means having the cam surface for contacting and separating the pressing member with respect to the mounting surface is provided, at least the pressing member facing the image reading means in the preliminary scanning mode. The part can be separated from the placement surface, and in this scanning mode, the pressing member can be brought close to the placement surface. In other words, at least in a portion facing the image reading unit, the gap between the document placed on the placement surface and the pressing member is larger when the preliminary scanning mode is executed than when the main scanning mode is executed. Become. Therefore, when the size of the original is read even if the presser member is colored white to reduce the influence on the original reading (main scanning mode) and the color of the presser member approximates the original color (preliminary) In the scanning mode), the boundary line between the original (the side edge) and the pressing member can be easily recognized by the image reading means, so that the size of the original can be read correctly.
According to the first aspect of the present invention, the cam means can be displaced using the movement of the image reading means, and the pressing member is moved toward and away from the mounting surface by the cam surface of the cam means. Can do.

  Note that the approach of the pressing member to the placement surface described above includes a state in which the pressing member is in direct contact with the placement surface and a state in which the pressing member holds the document between the placement surface.

  According to the second aspect of the present invention, since the pressing member is a flat plate-like member, the entire pressing member can be separated from the placement surface by the contacting / separating means.

According to the third aspect of the present invention, since the cam means is disposed on the opposite side of the placement surface of the document table as the image reading means, the cam means can be brought into contact with the image reading means. Easy to do. Further, since a hole is formed in the peripheral portion, the cam surface formed on the cam means is brought into contact with the protruding portion of the presser member arranged on the placement surface side of the document table through the hole. It becomes possible to make it.

According to the fourth aspect of the present invention, the abutting portion of the cam means is disposed outside the moving range in which the image reading means moves when performing the main scanning mode, and the image reading means and the image reading means as required. Abut. That is, the contact portion of the cam means is disposed at a position that does not interfere with the moving range of the image reading means in the main scanning mode. Therefore, once the cam means is displaced so as to correspond to the main scanning mode and the pressing member is brought close to the mounting surface, the image reading means is in contact with the cam means while the image reading means performs the main scanning mode. There is no need for contact and there is no risk of contact.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. This embodiment shows a multi-function device 1 (MFD: Multi Function Device) having a scanner function, a copy function, a facsimile function, and a printer function as an embodiment that embodies an image reading apparatus.

  In the multi-function device 1, an image reading device 10 for reading a document in a scanner function, a copy function, and a facsimile function is disposed on an upper portion of a synthetic resin main body case (housing) 2. A lid 11 covering the upper part of the image reading apparatus 10 is attached so as to be openable and closable around a rear end (the back side in FIG. 1).

  In the present embodiment, as shown in FIG. 1, a recording unit 3 (see FIG. 2) is provided below the image reading device 10, and a sheet that is a recording medium with respect to the storage space at the bottom of the main body case 2. Are fed in a stacked state, and a paper feed cassette device 5 that is integrally provided with a paper discharge tray section 4 is provided so that it can be inserted and removed. In addition, an operation unit 6 including buttons and switches for performing various operations and a panel display unit such as a liquid crystal is provided on the upper part of the front surface of the main body case 2.

  The recording unit 3 is provided with an ink jet recording head 7, and ink is ejected from the sheet feeding cassette device 5 to a sheet conveyed to the recording unit 3 through a conveyance path 8 formed in a U-turn shape. To record an image. The paper for which recording has been completed is discharged to the paper discharge tray section 4.

  The image reading apparatus 10 is a so-called flatbed scanner type that creates image data by reading an image (including a photograph and a document) of a stationary document. In the multi-function device 1, based on the image data read by the image reading device 10, it is transmitted via a telephone communication network using a facsimile function, recorded on a sheet as a recording medium using a copy function, Or transmitted to a personal computer or the like connected via the network. Note that an automatic document feeder (ADF) may be attached to the flatbed scanner type image reading apparatus 10 of the present embodiment, but the omitted form will be described here.

  As shown in FIG. 3, the image reading apparatus 10 of the first embodiment is provided with a document table 14 having a transparent glass plate 12 on which a document G is placed and a peripheral portion 13. The peripheral portion 13 is a thin plate-like member whose inner periphery and outer periphery are both formed in a rectangular shape in plan view, and the outer periphery of the peripheral portion 13 is formed to be slightly larger than the outer periphery of the glass plate 12. The peripheral portion 13 is superimposed above the glass plate 12, and the region of the glass plate 12 exposed from the inner periphery of the peripheral portion 13 becomes the document placement surface 15. The glass plate 12 and the peripheral portion 13 are both arranged so that the short sides thereof are parallel to the X axis.

  Since the peripheral portion 13 has a thin plate shape, it protrudes by the thickness of the glass plate 12, and the inner peripheral surface of the peripheral portion 13 is positioned by abutting the document placed on the placement surface 15. Used for On the upper surface of the first side portion 13a that is one side parallel to the X-axis direction of the peripheral portion 13, a mark 16 for urging the user to place the document at an appropriate position on the glass plate 12 is printed. Further, the second side portion 13b and the third side portion 13c parallel to the Y-axis direction of the peripheral portion 13 will be described in detail later, but a hole for projecting the cam portion 42 of the cam means 40 upward. A portion 35 is drilled. Two holes 35 are formed in each side 13b, 13c at intervals in the Y-axis direction.

  An image reading unit 20 is disposed below the glass plate 12. The image reading means 20 is a so-called line image sensor that irradiates light on a document through a glass plate 12 from a light source, condenses reflected light from the document on a light receiving element using a lens, and converts the light into an electric signal. The image reading means 20 is long in the X-axis direction and is provided so as to be reciprocally movable in the Y-axis direction along the guide shaft 21 by a known traveling mechanism. Although the CIS (Contact Image Sensor) is applied to the image reading means 20, a CCD (Charge Coupled Devise) may be used.

  On the lower surface side of the first side portion 13a in the peripheral portion 13 described above, a white portion and a black portion (both not shown) are formed for the image reading means 20 to acquire white reference and black reference data. Has been. In this embodiment, as shown in FIG. 4, a position below the first side 13 a and close to the placement surface 15 is set as the standby position 25 where the image reading unit 20 waits when there is no command. .

  As shown in FIG. 3, a pressing member 17 for pressing the document toward the placement surface 15 is provided on the lower surface side of the lid 11 facing the document table 14. In addition, the upper and lower sides of the lid body 11 and the pressing member 17 are described based on the vertical direction with the lid body 11 closed. The pressing member 17 is disposed between the pressing surface portion 30 and the pressing surface portion 30 that are colored white at least on the surface of the document table 14, and the pressing surface portion 30 and the lid body 11. The base 31 is provided. The planar view shape of the pressing surface portion 30 is the same as the planar view shape of the placement surface 15. The pressing surface portion 30 and the base portion 31 are supported by the lid body 11 so as to be movable up and down. For this reason, the pressing surface portion 30 moves toward and away from the placement surface 15 with the lid body 11 closed. be able to.

  The structure of the lid body 11 and the pressing member 17 in this embodiment will be described with reference to FIG. 4 to 6 schematically illustrate the dimensions in the vertical (thickness) direction. The pressing member 17 has an arm portion 32 extending from the upper surface of the base portion 31 toward the lid body 11, and an elongated hole 33 extending vertically is formed in the arm portion 32.

  On the other hand, a hook-like member 18 that hangs down on the document table 14 side is provided on the lid body 11 side, and this hook-like member 18 is inserted into and engaged with the elongated hole 33 of the presser member 1. That is, when the pressing member 17 (pressing surface portion 30) is moved toward and away between the position approaching the mounting surface 15 and the separated position by the cam means 40 described later, the elongated hole 33 serves as a guide. Thus, the engagement position of the hook-shaped member 18 with respect to the elongated hole 33 changes vertically. The approach mentioned here includes a state in which the pressing surface portion 30 is in direct contact with the placement surface 15 and a state in which the pressing surface portion 30 holds the document between the placement surface 15. In the present embodiment, the pressing surface portion 30 presses the document or the placement surface 15 by its own weight, but between the base portion 31 and the lid body 11, an elastic member that urges the pressing member 17 toward the placement surface 15. May be arranged.

  The base portion 31 is formed to have a larger planar view shape than the pressing surface portion 30, and each hole portion 35 (here, the region exposed on the second side portion 13b and the third piece portion 3c side on the lower surface of the base portion 31). Projecting portions 34 projecting toward the peripheral portion 13 are provided so as to oppose to all four locations. The projecting height of the projecting portion 34 is such that when the pressing surface portion 30 is in direct contact with the placement surface 15 (at the time of reading, it is in contact with the placement surface 15 via the document G), the projecting portion 34 and the peripheral portion 13. (See FIGS. 4 (a) and 4 (b)).

  Cams extending in parallel with the second and third side portions 13b and 13c below the second side portion 13b and the third side portion 13c in the peripheral portion 13 of the document table 14 and above the image forming means 20, respectively. Means 40, 40 are arranged, and each cam means 40 is supported so as to be movable in the Y-axis direction. The cam means 40 is a thin thin plate member, and is formed longer in the Y-axis direction than the placement surface 15 outside the region of the glass plate 12 in the X-axis direction. A contact portion extending downward is formed in each of the adjacent portions.

  The contact portions at both ends of the cam means 40 are all provided outside the area of the placement surface 15 (area in which the image reading means 20 moves in the main scanning mode described later) and close to the standby position 25 ( The contact portion located on the left side in FIG. 4 is referred to as a first contact portion 41a, and the contact portion located on the side far from the standby position 25 (right side in FIG. 4) is referred to as a second contact portion 41b. In this embodiment, the cam means 40 is individually provided below the second side portion 13b and the third side portion 13c. However, a bridge portion for connecting the two cam means 40 is provided. And you may form integrally.

  On the upper surface of the cam means 40, as shown in FIG. 4, cam portions 42 having a substantially trapezoidal shape when viewed from the front are formed at two locations separated in the Y-axis direction. The cam portion 42 has a cam surface that is higher than the upper surface of the cam means 40 and is connected to the upper surface 42a in parallel with the upper surface 42a, and connects the top surface 42a and the upper surface of the cam means 40 to the arrow A side ( And an inclined surface 42b continuous on the side close to the standby position 25. The distance between the top surface 42a and the upper surface of the cam means 40 (projection height of the top surface 42a) is the document (exceptional) placed on the placement surface 15 when the projection 34 abuts the top surface 42a. In other words, a slight gap is generated between the upper surface of the general-purpose thickness original (excluding a thick original) and the pressing surface portion 30.

  Each cam portion 42 protrudes upward (on the pressing member 17 side) through each hole portion 35 formed in the second side portion 13b and the third side portion 13c. Since the cam portion 42 moves in the Y-axis direction as the cam means 40 moves, the hole portion 35 is formed in a size that allows the cam portion 42 to move in the Y-axis direction.

  The image reading means 20 has an end portion in the X-axis direction so that the image reading means 20 can move so as to overlap with the cam means 40 disposed below the second side portion 13b and the third piece portion 13c. And longer in the X-axis direction. Accordingly, when both end portions of the image reading unit 20 in the X-axis direction move in the direction of the arrow A while contacting the first contact portions 41a of the two cam units 40, the two cam units 40 are simultaneously moved in the direction of the arrow A. Can be moved. A position where the cam means 40 moves further in the direction of arrow A after passing the standby position 25 shown in FIG. Further, when both end portions of the image reading means 20 in the X-axis direction move in the direction of arrow B (see FIGS. 3 and 4) while being in contact with the second contact portions 41b of the two cam means 40, the two cams The means 40 can be moved in the direction of the simultaneous arrow B. A position where the cam means 40 has moved to the opposite side across the placement surface 15 with respect to the standby position 25 shown in FIG.

  The positional relationship between the cam portion 42 formed on the cam means 40 and the protruding portion 34 formed on the pressing member 17 is just before the cam means 40 moves in the direction of arrow A and reaches the first movement position 26. The protruding portion 34 and the inclined surface 42b of the cam portion 42 are in contact with each other, and when the first moving position 26 is reached, the protruding portion 34 and the top surface 42a of the cam portion 42 are in contact with each other. The protruding portion 34 is in a state where a gap is opened between the protruding portion 34 and the peripheral portion 34 except when the protruding portion 34 is in contact with the top surface 42 a and the inclined surface 42 b of the cam portion 42.

  Next, with reference to FIG. 7, a control unit 300 as a control unit of the image recording apparatus 1 will be described. The control unit 300 controls the overall operation of the multi-function device 1.

  The control unit 300 is configured around a microcomputer including a CPU 301, a ROM 302, a RAM 303, and an EEPROM 304, and an ASIC (Application Specific Integrated Circuit) 306 connected to the microcomputer via a bus 305.

  The ROM 302 stores programs for controlling various operations of the multi-function device 1, and the RAM 303 is used as a storage area for temporarily storing various data used when the CPU 301 executes these programs. Used as a region.

  Image data created by reading an original with the image reading means 20 (image scanner) of the image reading apparatus 10 and image data received from an external device such as the computer 311, another facsimile machine, or the storage medium 312 are also temporarily stored in the RAM 303. It is stored as bitmap data by the ASIC 306 in the image data area.

  A network control unit (NCU) 324 is connected to the ASIC 306, and a communication signal input from the public line (PSTN) via the NCU 324 is demodulated by the modem 325 and then input to the ASIC 306. When the ASIC 306 transmits image data to the outside by facsimile transmission or the like, the image data is modulated into a communication signal by the modem 325, and the communication signal is output to the public line via the NCU 324.

  The ASIC 306 generates, for example, a phase excitation signal for energizing each motor in accordance with a command from the microcomputer, and supplies it to the drive circuit of each motor. Examples of the drive circuit include a drive circuit 311 that controls a drive source 312 in the Y-axis direction of the image reading unit 20 and a drive circuit 310 that controls ejection of the recording unit 3.

  Further, the ASIC 306 is used to transmit / receive data to / from external devices such as a panel interface 320 having the operation unit 6 having a panel for various operations and an input unit, and a personal computer 326 via a parallel cable or a USB cable. A parallel interface 321, a USB interface 322, a memory interface 323 having an external input terminal to which a storage medium 327 is attached are connected.

  Since various image data to be recorded by the recording unit 3, such as image data read by the image reading means 20, is stored in the image data area in the RAM 303, data is sequentially read from this area by the ASIC 306. The image is recorded on the paper by the recording head 7.

  As the scanning mode of the image reading means 20, a preliminary scanning mode for detecting the size of the document and a main scanning mode for reading the content of the document and creating image data are set. In each scanning mode, not only the processing of the read data is different, but also the movement range in the Y-axis direction of the image reading means 20 is displaced in the cam means 40 in the preliminary scanning mode than in the main scanning mode. To make it bigger. When an original is placed on the placement surface 15 and an instruction to read the original is issued from the operation unit 6 or an external device such as the computer 326, the control unit 300 operates the image reading unit 20 in the pre-scan mode. Subsequently, it is configured to operate in the main scanning mode.

  An image reading operation of the image reading apparatus 10 having the above configuration will be described with reference to a flowchart of FIG. First, the image reading means 20 is located at the standby position 25 as shown in FIG. When the original G is placed on the placement surface 15 and a reading instruction for the original G is issued (S01), first, the image reading means 20 acquires white reference and black reference data at the standby position 25. (S02).

  When the presser member 17 is in the approach position approaching the placement surface 15 (Yes in S03), the image reading unit 20 moves from the standby position 25 in the direction of arrow A, and the image reading unit 20 has two The first abutting portion 41a of the cam means 40 is abutted and pushed forward. As a result, the projecting portion 34 of the pressing member 17 contacts the inclined surface 42 b of the cam portion 42, and the pressing surface portion 30 is gradually separated from the placement surface 15. Then, as shown in FIGS. 5A and 5B, when the image reading means 20 reaches the first movement position 26 (S04), the protruding portion 34 comes into contact with the top surface 42a of the cam portion 42. Then, the pressing surface portion 30 rises to a separation position separated from the placement surface 15 (S05). A gap ΔL is generated between the pressing surface 30 and the original G.

  With the top surface 42a of the cam portion 42 and the protruding portion 34 in contact with each other, the image reading means 20 operates in the preliminary scanning mode (S06). That is, while the slight gap ΔL is generated between the pressing surface portion 30 and the original G, the cam means 40 is not displaced and only the image reading means 20 moves the area corresponding to the placement surface 15 in the arrow B direction. To read the size of the original G.

  As described above, when the preliminary scanning mode is performed, the gap ΔL is formed between the document G and the pressing surface portion 30. That is, the distance between the image reading means 20 (light receiving element) and the original G and the image reading means 20 (light receiving element) are compared with the case where the original G and the pressing surface portion 30 are in close contact (see FIG. 4B). And the distance of the pressing surface part 30 are clearly different. Therefore, even when both the original G and the pressing surface portion 30 are approximated in white, the image reading unit 20 (light receiving element) can clearly determine the boundary between the original G and the pressing member 17.

  When the reading of the document size (preliminary scanning mode) is completed, the image reading means 20 further moves outside the area of the placement surface 15 in the direction of arrow B and comes into contact with the second contact portion 41b of the cam means 40. This is advanced while reaching the second movement position 27 as shown in FIG. 6 (S07). By the movement of the cam means 40 in the direction of arrow B, the contact between the projecting portion 34 and the cam portion 42 is released, and the pressing surface portion 30 presses the original G placed on the mounting surface 15. Approach 15

  Next, in order to operate in the main scanning mode, the image reading unit 20 once moves in the arrow A direction and is positioned at the standby position 25, and then reads the document G while moving again from the standby position 25 in the arrow B direction. Perform (S08). When the main scanning mode is executed, the document G is pressed against the placement surface 15 by the pressing surface portion 30, so that the document G can be reliably read without being displaced. When the same document G needs to be read again, the image reading means 20 reciprocates in the Y-axis direction inside the area of the placement surface 15 while the pressing surface portion 30 presses the document. do it.

  Further, the reading of the original G in the main scanning mode may be performed while moving from the second movement position 27 in the direction of the arrow A instead of once returning from the second movement position 27 to the standby position 25. . Further, the white reference and black reference data acquisition of S02 may be executed immediately before the main scanning mode.

  When the image reading ends (S09), the image reading means 20 moves to the standby position 25 and waits for the next command (S10).

  As described above, in the present embodiment, the preliminary scanning mode for detecting the size of the document is performed prior to the main scanning mode for reading the document, but the pressing surface portion 30 (pressing member 17) for pressing the document is mounted. It is provided so as to be movable toward and away from the mounting surface 15. Therefore, in the preliminary scanning mode, a gap ΔL (see FIG. 4B) is generated between the pressing surface portion 30 and the document G, and the document size is correctly detected even when the pressing surface portion 30 is white. Can do.

  On the other hand, in the main scanning mode, since the original is pressed against the placement surface 15 by the pressing surface portion 30, the original can be reliably read while preventing the deviation of the original. Of course, since the pressing surface portion 30 is white, there is no concern that the color of the pressing surface portion 30 adversely affects the reading of the document.

  In the above-described embodiment, there is a slight possibility that the document is displaced due to the wind pressure caused by the contact and separation of the pressing member 17. In such a case, the applicant may join a document placing auxiliary member made of a transparent sheet material to the document table 14 as disclosed in Japanese Patent Application Laid-Open No. 2007-104093. . In this case, the document is placed such that a part or all of the document is sandwiched between the lower surface of the document placement assisting member and the placement surface 15, and the lid 11 is rotated and the presser member 17 is moved. Even when wind pressure is generated by the contact / separation movement, it is possible to prevent the document from being displaced from an appropriate position. Of course, since the document placement assisting member is transparent, there is no fear of adversely affecting the document reading or the document size detection.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the image reading apparatus 10 according to the second embodiment, an electromagnetic solenoid 50 is used as means for moving the pressing surface portion 30 of the flat pressing member 17 to and away from the document table 14. When the electromagnetic solenoid 50 is demagnetized, the pressing surface portion 30 approaches the placement surface 15 of the document table 14, and when the electromagnetic solenoid 50 is excited, the pressing surface portion 30 is separated from the document table 14. The pressing surface portion 30 is urged toward the mounting surface 15 by an elastic member 51 such as a spring disposed between the pressing surface portion 30 and the lid body 11. The arrangement position of the electromagnetic solenoid 50 and the connection configuration with the flat plate-like pressing member 17 are not limited to those in FIG. 9 and can be changed as appropriate.

  Also in the configuration of the second embodiment, as in the first embodiment, when the image reading unit 20 performs the preliminary scanning mode, the pressing surface portion 30 is separated from the document table 14 and the image reading unit 20 performs the main scanning mode. When performing, the pressing surface portion 30 is made to approach the document table 14. Thereby, the effect similar to 1st Embodiment is acquired.

  Next, another embodiment of the present invention will be described with reference to FIG. The pressing member 17 according to the third embodiment is made of a flexible material, and the entire pressing member 17 does not move toward and away from the document table 14 but is opposed to the image reading unit 20. Is partially separated from the mounting surface 15 along the movement of the image reading means 20 in the Y-axis direction. That is, since a line image sensor is employed as the image reading unit 20, if the pressing member 17 is separated from the placement surface 15 (document) only in the vicinity of the line corresponding to the image reading unit 20, The same effect as in the first embodiment can be obtained.

  In the third embodiment shown in FIG. 10A, while the pressing member 17 is provided with a flexible pressing surface portion 130, the pressing member 17 and the pressing member 17 are arranged in the X-axis direction inside the lid body 11 facing the pressing surface portion 130. A large number of electromagnets 52 that are equally long are arranged in parallel along the Y-axis direction. On the other hand, the surface on the lid 11 side of the pressing surface portion 130 is formed of a magnetic body 53.

  In the above-described configuration, the pressing surface portion 130 is partially attracted to the electromagnet 52 by energizing the electromagnet 52 at the portion facing the image reading device 20 in conjunction with the movement of the image reading device 20, and the attracted pressing surface portion. 130 parts are separated from the mounting surface 15. Thereby, the same effect as the first embodiment can be obtained.

  In the fourth embodiment shown in FIG. 10B, the pressing member 17 is made of a material having flexibility in the Y-axis direction and rigidity in the X-axis direction as the pressing surface portion 230. For example, a plastic pressing member 17 having white rigidity (shape retention) is used, the surface on the mounting surface 15 side of the pressing surface portion 230 is a flat surface, and the surface on the lid body 11 side on the pressing surface portion 230 is X. A large number of slits 55 that are long in the axial direction are arranged in parallel in the Y-axis direction. That is, the pressing surface portion 230 is given flexibility in the Y-axis direction by the cuts 55.

  On the other hand, a columnar auxiliary member 56 having a short length in the X-axis direction is disposed on the second side 13b and the third side 13c of the peripheral portion 13 of the document table 14, and reciprocates in the Y-axis direction. Supported as possible. The two auxiliary members 56 move integrally in the Y-axis direction (either rolling or sliding) in conjunction with the movement of the image reading means 20 in the Y-axis direction.

  That is, since the pressing surface portion 230 has rigidity in the X-axis direction, when the auxiliary member 56 supports and lifts only both ends of the pressing surface portion 230 in the X-axis direction, the pressing surface portion 230 has a length in the X-axis direction. Everything is lifted, creating a gap with the document. Therefore, when the auxiliary member 56 moves in the Y-axis direction in conjunction with the movement of the image reading means 20, the portion of the pressing surface portion 230 that is lifted by the auxiliary member 56 also changes in the Y-axis direction. Thereby, the effect similar to 1st Embodiment is acquired.

  The auxiliary member 56 is not limited to the structure shown in FIG. 10B, and the second side portion 13b and the third side portion 13c are each provided with a slit portion extending in the Y-axis direction. Alternatively, the auxiliary member 56 may protrude upward from below.

1 is a perspective view of a multi-function device including an image reading device of the present invention. It is the II-II sectional view taken on the line of FIG. It is a perspective view of an image reading device in a state where a lid is opened. (A) is a typical figure of the IVa-IVa arrow directional cross section of FIG. 3, (b) is a schematic figure of the IVb-IVb arrow directional cross section of FIG. 4A corresponds to FIG. 4A when the image reading unit is at the first movement position, and FIG. 4B corresponds to FIG. 4B when the image reading unit is at the first movement position. FIG. FIG. 5 is a diagram corresponding to FIG. 4A when the image reading unit is at the second movement position. It is a block diagram of a control part. 6 is a flowchart illustrating an operation in a document image reading command. It is a schematic diagram of the image reading apparatus of the second embodiment. (A) is a schematic diagram of the image reading apparatus of the third embodiment, and (b) is a schematic diagram of the image reading apparatus of the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multifunctional device 10 Image reading apparatus 11 Cover body 12 Glass plate 13 Peripheral part 13a 1st side part 13b 2nd side part 13c 3rd side part 14 Document stand 15 Placement surface 17 Holding member 20 Image reading means 25 Standby position 26 First moving position 27 Second moving position 30 Press surface portion 31 Base portion 34 Protruding portion 35 Hole portion 40 Cam means 41a First contact portion 41b Second contact portion 42 Cam surface 42a Top surface 42b Inclined surface 50 Electromagnetic solenoid 300 Control unit

Claims (4)

A document table having a placement surface on which a document is placed and a peripheral portion surrounding the placement surface; an image reading unit arranged on the opposite side of the placement surface of the document table to read the document; and the document table an image reading apparatus and a lid for opening and closing the placement surface side with respect to the platen not covered in,
A pressing member that is provided on a surface of the lid on the platen side and that presses the document placed on the placement surface ;
Cam means displaced by movement of the image reading means;
A cam surface that is provided in the cam means and contacts the presser member and moves the presser member against and away from the mounting surface;
Control means for controlling the operation of the image reading means,
The control means has a preliminary scanning mode in which the size of the original is detected by the image reading means, and a main scanning mode in which the original is read by the image reading means,
In the preliminary scanning mode, at least a portion of the pressing member facing the image reading unit is separated from the placement surface by the cam unit ,
In the main scanning mode, the pressing member is brought close to the mounting surface by the cam means.   The pressing member is a flat plate-like member facing the mounting surface, and the entire pressing member is separated from the mounting surface in the preliminary scanning mode, and approaches the mounting surface in the main scanning mode. The image reading apparatus according to claim 1, wherein: The cam means is disposed on the opposite side of the document table on the document table, and the cam surface is in contact with a protruding portion provided on the pressing member side through a hole formed in the peripheral portion. The image reading apparatus according to claim 1 or 2 . The cam means has a contact portion that contacts the image reading means, and the contact portion is disposed outside a moving range in which the image reading means moves when performing the main scanning mode. 4. The image reading apparatus according to claim 3 , wherein when the cam means is displaced, the image reading means is moved to a position where the image reading means comes into contact with the contact portion .

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