JP3919762B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus.

  Conventionally, when copying a document in a copying machine equipped with an automatic document feeder, the automatic document feeder supported in an openable / closable manner with respect to the image reading unit main body is used in a closed state. Documents can be fed one by one onto the platen one by one and automatically copied one by one. It is also possible to place the original on the platen directly for copying without using the automatic document feeder as an open state with respect to the image reading unit main body.

  The automatic document feeder automatically incorporates various parts such as various rollers and motors to automatically convey the document, so the weight of the device itself can be from several kilograms to several tens of kilograms. Therefore, it is common to provide an opening / closing mechanism having a hinge (also referred to as a hinge or a hinge).

  The hinge incorporates a spring, and this spring is urged and attached in a direction to open the automatic document feeder, that is, a direction to lift against the weight. With this structure, it can be lifted with a light force when opening, and the force in the direction of extension of the spring, that is, the force to push up and push down below the automatic document feeder to close gently when closing Is set to balance the weight of

Also, when the original is thick like a book, the upper surface of the original is covered horizontally with the pressure plate portion of the automatic original feeder, so that the direction of the support member is opposite to the opening direction of the support member. A lift member is attached so as to be rotated (reversed), a frame of the automatic document feeder is attached to the lift member, and a support member is attached in the opening direction in order to prevent reversal during normal operation. There has been disclosed an invention in which an elastic means is attached (see, for example, Patent Document 1).
JP-A-11-174597

  However, even in the configuration disclosed in Patent Document 1, the mechanism for preventing the reversal of the lift member is released at a place other than the intended state depending on the opening / closing operation of the automatic document feeder. May not be able to be performed smoothly.

  This is considered to result from the fact that the release of the mechanism that prevents the lift member from reversing is performed only depending on the opening / closing angle of the opening / closing mechanism being a certain angle.

  The present invention has been made in view of the above circumstances, and detects whether a document placed on a platen glass is a sheet-like document or a thick bookbinding document, and automatically feeds the document by an equalizing mechanism of a hinge portion. An object of the present invention is to provide an image reading apparatus in which an operator can smoothly open and close the apparatus without confusion.

  This invention can solve the said subject by providing the following structure.

An image reading apparatus according to a first aspect of the present invention includes a document feeding unit that feeds a document,
A platen glass for placing the document fed from the document feeding means;
An image reading unit that reads an image of a document placed on the platen glass, and a hinge unit that supports the document feeding unit so as to be openable and closable with respect to an image reading unit that accommodates the image reading unit, The document feeding means has an equalizing mechanism that can tilt and move up and down while rotating about the hinge shaft of the hinge portion, and the document feeding means selectively locks the equalizing mechanism. An image reading apparatus provided with an equalizing lock means that enables
The image reading apparatus includes detection means for detecting whether or not a document placed on the platen glass is a document having a predetermined thickness or more, and the detection unit is a document having a predetermined thickness or more. Is detected, the equalizing lock means is unlocked.

An image reading apparatus according to a second aspect has the same configuration as that of the first aspect,
The image reading apparatus includes a first detection unit that detects that an opening / closing angle of the document feeding unit is equal to or less than a predetermined angle with respect to the image reading unit, and a second detection unit that detects a bound document. And
The first detection means detects that the opening / closing angle of the document feeding means is less than a predetermined angle with respect to the image reading unit, and the second detection means is on the platen glass. When it is detected that the placed document is a document having a thickness greater than or equal to a predetermined thickness, the equalization lock unit is unlocked.

  According to the present invention, depending on the opening / closing operation of the automatic document feeder, the equalizing lock means of the equalizing mechanism is released at a place unintended by the operator, resulting in a problem that the opening / closing operation cannot be performed smoothly. Cover the bookbinding document so that the pressure plate of the automatic document feeder is parallel to the upper surface of the bookbinding document, and evenly press the bookbinding document against the platen glass with uniform force. It is possible to prevent problems such as damage to the bookbinding document due to local pressing force on the document, and copying such that one end of the bookbinding document is lifted off the platen glass. This presents an effect that the operator can smoothly open and close the feeding device without being confused.

  Embodiments of an image reading apparatus according to the present invention will be described below.

  FIG. 1 is an overall configuration external view showing an embodiment of a copier equipped with an image reading apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing a characteristic configuration of an automatic document feeder according to this embodiment. 3 is a cross-sectional view showing a locked state of the equalizing mechanism according to the present embodiment, and FIG. 4 is a diagram illustrating the automatic document feeder according to the present embodiment with respect to the scanner unit. FIG. 5 is a cross-sectional view showing a state where the equalizing mechanism is functioning when reading a bookbinding document, and FIG. 6 is a control for releasing the lock of the equalizing mechanism according to the present embodiment. It is a flowchart to show.

  The overall configuration of the copying machine will be described with reference to FIG.

  However, the image reading apparatus provided with the automatic document feeder having the equalizing mechanism according to the present invention is not limited to the one having the configuration described below.

  A copying machine 1 shown in FIG. 1 includes an image reading unit main body (hereinafter referred to as a main body) 100, a paper feed table 33 mounted on the lower portion of the main body 100, and an automatic document feeder mounted on the upper surface of the main body 100. (ADF) 2.

  The main body 100 has an image forming unit disposed substantially at the center thereof, and a paper feeding unit positioned below the image forming unit. A scanner unit having a CCD or the like as an image reading unit is disposed at the top of the main body 100. A space is provided between the scanner unit and the image forming unit to form a paper discharge space unit 34.

  In the main body 100, the image forming unit is configured as a conventionally known electrophotographic print engine, and incorporates a laser writing device, an electrophotographic process means, a fixing device and the like (not shown). The paper feed section has a plurality of stages (four stages shown) of paper feed cassettes 33 and supplies documents such as sheets to the image forming section. Each sheet feeding cassette 33 is a front loading type that pulls out toward the front side of the apparatus and replenishes the sheet, and a drawer handle is provided at the center of the front surface of the cassette.

  In the scanner unit, a platen glass 19 (see FIG. 2), which will be described later, is arranged on the upper surface, and a scanner unit (not shown) is arranged below the platen glass 19.

  The paper discharge space 34 is surrounded by two walls except for the front, that is, the left side and the back side of the apparatus in FIG. 1, and the upper and lower sides are surrounded by the scanner unit and the image forming unit.

  A paper discharge tray provided at the bottom of the paper discharge space 34 is provided on the upper surface of the image forming unit. In FIG. 1, a sheet discharge path is provided in the in-machine discharge cover that forms the left side wall, and a sheet that has been recorded by the image forming unit is discharged from a predetermined position in the height direction of the in-machine discharge cover. It is discharged onto the tray.

  Regarding other reference numerals, A is a hinge portion, KE is an equalizing mechanism of the hinge portion A, and LE is an equalizing lock means.

  The automatic document feeder 2 is mounted on the upper part of the main body 100 via an equalizing mechanism KE of a hinge part A provided on the back side of the apparatus, and is disposed so as to be openable and closable so as to cover the platen glass 19 on the upper surface of the scanner part. Has been. Since the configuration and operation of the automatic document feeder 2 are the same as those conventionally known, a detailed description thereof will be omitted. However, a document bundle (not shown) set on the document table 31 is one sheet from the lower side. The originals that are conveyed one by one on the platen glass 19 and have been read and scanned by the scanner unit are discharged onto the original discharge table 32.

  The automatic document feeder 2 can be used as a pressure plate for copying (pressure plate mode) not using automatic paper feeding or for copying a bookbinding document such as a book or a notebook (bookbinding document mode).

  FIG. 2 is a sectional view showing details of the equalizing mechanism in a state where the automatic document feeder is open with respect to the scanner unit.

  Reference numeral 2 denotes an automatic document feeder (ADF).

  The automatic document feeder 2 is covered with a cover frame (exterior component member) 3. The main body 100 is provided with a platen glass 19 for reading an image on the upper surface, and a stage for reading an image of a placed document. A pressure plate portion (white pressure plate) 21 is disposed on the opposite side of the platen glass 19 and is attached to the automatic document feeder 2 via a pressure plate sponge 20.

  The pressure plate sponge 20 made of an elastic body is set to a soft elastic force as much as possible within a range in which a necessary pressing force can be obtained because the sheet original is urged and attached to the platen glass 19 in the pressure plate mode. Yes. When the bookbinding document is placed on the platen glass 19, the pressure plate sponge 20 is deformed to absorb a part of the pressing force, and the pressure plate portion (white pressure plate) 21 is automatically printed without applying a large pressing force to the bookbinding document. It is configured to push up toward the feeding device.

  A bookbinding document detection sensor 103 constituted by a photo interrupter is built in the automatic document feeder 2, and a bookbinding document detection flag 102 is provided in the pressure plate portion (white pressure plate) 21. As shown in FIG. 5 to be described later, when the pressure plate portion (white pressure plate) 21 is pushed up while being deformed so that the pressure plate sponge 20 is crushed, the bookbinding document detection flag 102 shields the bookbinding document detection sensor 103 (the sensor is turned on). By doing so, it is possible to detect whether or not the document placed on the platen glass 19 is a bookbinding document having a thickness greater than a predetermined thickness. The predetermined thickness value at this time is determined by the positional relationship between the bookbinding document detection sensor 103 and the bookbinding document detection flag 102. The bookbinding document detection sensor 103 is also characterized in that it detects when the pressure plate unit 21 comes into contact with the document. When the bookbinding document detection sensor 103 is turned on, the automatic document feeder 2 is controlled by the platen glass. 19, it is determined that the document placed on 19 is touched. As a result, the lock can be released when the automatic document feeder 2 comes into contact with the placed document at the unlocking timing of the equalizing mechanism KE described later.

  The bookbinding original detection sensor 103 is provided with a piezoelectric element between the pressure plate portion (white pressure plate) 21 and the cover frame 3 instead of the flag and the photo interrupter, and if the output of the piezoelectric element becomes a predetermined value or more, the bookbinding original detection sensor 103 becomes a bookbinding original. Even if detected, the object of the present invention is achieved.

  On the other hand, the scanner unit is provided with an ADF open / close detection sensor 104 and an ADF open / close detection flag 101 configured by a photo interrupter. When the open / close angle of the automatic document feeder (ADF) 2 becomes a certain value or less, an ADF open / close detection is performed. When the flag 101 is pressed and the ADF opening / closing detection sensor 104 is shielded from light (the sensor is turned on), it is detected that the automatic document feeder 2 is closed.

  As a mechanism for enabling the automatic document feeder (ADF) 2 to be opened and closed with respect to the platen glass 19, a hinge shaft 13 of a hinge portion is attached to the cover frame 3. The hinge portion is rotatable about the hinge shaft 13 via the hinge arm 7 and constitutes an opening / closing mechanism of the automatic document feeder 2. The equalizing mechanism includes a lift arm 4, a lift shaft 5, a spring shaft 6, a hinge arm 7, a hinge shaft 13, a hinge base 14, a spring holder lower 15, a compression spring 16, a spring holder 17 and a spring shaft 18. The

  The hinge shaft 13 is pivotally supported by a hinge base 14, and the hinge base 14 is fixed to the main body 100. Further, since the hinge arm 7 supports the hinge shaft 13, the hinge arm 7 can rotate with respect to the hinge base 14.

  The hinge arm 7 supports the lift arm 4 via the lift shaft 5, and the lift arm 4 is rotatable with respect to the hinge arm 7. Therefore, the hinge arm 7 can be rotated in a direction opposite to the opening direction of the hinge arm 7.

  The lift arm 4 is fixed to the cover frame 3 and supports the spring shaft 18. The upper spring shaft 18 supports the upper spring holder 17.

  The lift arm 4 is provided with an equalizing lock means for locking the lift arm 4 so that the lift arm 4 cannot rotate with respect to the hinge arm 7. The equalizing lock means includes a solenoid 106 and a lock claw 105. Details of the equalizing lock means will be described later.

  The upper spring holder 17 holds one end of the compression spring 16, and the lower spring holder 15 is arranged on the opposite side to hold the other end of the compression spring 16. The lower spring holder 15 is pivotally supported by the lower spring shaft 6.

  Since the lower spring shaft 6 is fixed to the hinge base 14, the distance between the upper spring shaft 18 and the lower spring shaft 6 is changed by the opening / closing operation of the automatic document feeder 2, and the compression spring 16 expands and contracts accordingly. The spring force changes.

  The seat cover (for protecting the hinge portion) 9 fixes a part of the upper end to the cover frame 3. The material is an EPDM rubber sheet that can be easily molded, is elastic and bends freely, and returns to its original shape by itself.

  A guard plate (reinforcing part, plate-like member) (not shown) formed of ABS resin is attached to the seat cover 9.

  FIG. 3 is a sectional view showing a locked state of the equalizing lock means.

  The equalizing lock means LE is mainly composed of a solenoid 106 and a lock claw 105. The solenoid 106, a lock claw 105 that can be rotated around a support shaft 105a when the solenoid 106 is turned on, the lock claw 105, and the solenoid. The spring member 105 b is interposed between the spring member 105 and the member 106.

  Normally, the solenoid 106 is turned off, and the lock claw 105 is engaged with the hinge arm 7 and the lift arm 4 together by the spring member 105b as shown in FIG. It is locked so that it cannot rotate.

  When the solenoid 106 is turned on, the lock claw 105 rotates in the counterclockwise direction as shown by the arrow in the figure about the support shaft 105a by the operation in the arrow C direction in the figure against the spring force of the spring member 105b. Can be unlocked. At this time, the lift arm 4 is configured to be able to rotate with a force as light as possible with respect to the hinge arm 7. When the bookbinding document P is placed on the platen glass 19 by the above-described unlocking configuration of the equalizing lock means LE, the equalizing mechanism KE functions and balances without applying a large pressing force to the bookbinding document P. Thus, it is possible to reduce as much as possible the damage caused by locally crushing the bookbinding document P.

  The equalizing mechanism KE used in the present invention is compatible with both a pressure plate mode for handling a sheet-like document and a book mode for handling a book-binding document. In the book mode, the book-binding document is damaged. It means an equilibrium state holding mechanism that can reduce the pressing force without applying an excessive pressing force and balance the pressing force and the counter pressing force to maintain the equilibrium state.

  FIG. 4 shows a state where the automatic document feeder 2 is closed when a sheet-like document is placed on the platen glass 19.

  When the automatic document feeder 2 is closed, the ADF open / close detection flag 101 is pressed by the lower surface of the automatic document feeder, and the ADF open / close detection sensor 104 is shielded to confirm that the automatic document feeder 2 is closed. Detect. When a sheet-like document is placed on the platen glass 19, the pressure plate portion (white pressure plate) 21 is not pushed up, so that the bookbinding document detection sensor 103 is not turned on. As a result, the equalizing lock means remains locked. is there.

  FIG. 5 shows a state in which the bookbinding document is placed on the platen glass 19 and the automatic document feeder 2 balances the pressing force and the counter pressing force by the equalizing mechanism.

  When the automatic document feeder 2 is to be closed while the equalizing lock means LE is locked, the ADF open / close detection sensor 104 is turned on when the automatic document feeder 2 is opened or closed at a predetermined angle or less. In this state, the automatic document feeder 2 is further closed and when the original placed on the platen glass 19 is a bookbinding original P having a thickness h greater than or equal to a predetermined thickness h, the booklet original P causes the pressure plate portion (white pressure plate). When 21 is pushed up and the bookbinding original detection sensor 103 is turned on, the solenoid 106 of the equalizing lock means LE is turned on, and the lock claw 105 rotates counterclockwise around the support shaft 105a to release the equalizing lock means. The Along with this, the bookbinding document P is covered so that the pressure plate portion 21 of the automatic document feeder 2 is parallel to the upper surface of the bookbinding document, and the bookbinding document P is attached to the platen glass 19 with a uniform force evenly. Such as damage to the bookbinding document P due to local pressing force applied to the bookbinding document P, or copying with the one end of the bookbinding document P floating from the platen glass 19. Can be prevented.

  FIG. 6 is a flowchart showing control for releasing the lock of the equalizing mechanism KE.

  When the ADF open / close detection sensor 104 is turned on and it is determined that the automatic document feeder 2 is closed at a predetermined angle or less (S1), it is monitored whether or not the bookbinding document detection sensor 103 is turned on (S2). When it is determined that the bookbinding original detection sensor 103 is turned on, the equalizing lock means LE is released by turning on the solenoid 106 of the equalizing lock means LE (S3).

  When it is detected that the bookbinding original detection sensor 103 is turned off (S4), the solenoid 106 is turned off and the equalizing lock means is locked again regardless of the output of the ADF open / close detection sensor 104 (S5).

  As described above, when the automatic document feeder 2 is closed to a predetermined angle or less (ADF open / close detection sensor 104) and a bookbinding document having a thickness greater than a predetermined thickness is detected (bookbinding document detection sensor 103), that is, By operating the two sensors (103, 104) to release the lock, when the automatic document feeder 2 is opened and closed, the lock is released and the smooth operation can be performed where the operator does not intend. It is prevented from disappearing.

  On the other hand, when the equalizing lock means LE is locked again, the equalizing lock is performed as soon as possible by determining only that the bookbinding original detection sensor 103 is turned off regardless of the opening / closing angle of the automatic document feeder 2. The means LE is locked to realize a smooth opening / closing operation of the automatic document feeder 2.

  Further, as in the present embodiment, there is a second detecting means 103 for detecting whether or not the original has contacted the pressure plate portion 21 of the original feeding means 2, and this second detecting means 103 is a platen. Only when it is detected that the original placed on the glass 19 has come into contact with the pressure plate portion 21 of the original feeding means 2, the equalizing mechanism KE can be made to function at the minimum necessary by releasing the equalizing lock means LE. In addition, since the operation stroke in a state where the equalizing mechanism KE is functioning can be made the minimum stroke, it is possible to prevent the operator from being confused by making a complicated movement.

  The first detection means used in claims 3 and 4 is the ADF open / close detection sensor 104, and the second detection means is the bookbinding document detection sensor 103.

FIG. 1 is an external view of an overall configuration showing an embodiment of a copier equipped with an image reading apparatus according to the present invention. Sectional drawing which shows the characteristic structure of the automatic document feeder based on this embodiment (The state which is open with respect to a scanner part) Sectional drawing which shows the locked state of the equalizing mechanism which concerns on this embodiment Sectional drawing which shows the state in which the automatic document feeder based on this embodiment is closed with respect to the scanner part Sectional drawing which shows the state in which the equalization mechanism at the time of reading a bookbinding original of the automatic document feeder based on this embodiment is functioning. 10 is a flowchart showing control for releasing the lock of the equalizing mechanism of the automatic document feeder according to the present embodiment.

Explanation of symbols

1 Copier 2 Document Feeder (Automatic Document Feeder, ADF)
3 cover frame 4 lift arm 5 lift shaft 6 spring shaft lower 7 hinge arm 9 seat cover 13 hinge shaft 14 hinge base 15 spring holder lower 16 compression spring 17 spring holder upper 18 spring shaft upper 19 platen glass 20 pressure plate sponge 21 pressure plate ( White pressure plate)
100 Image reading unit main body (image reading apparatus)
101 ADF open / close detection flag 102 Bookbinding document detection flag 103 Bookbinding document detection sensor (second detection means)
104 ADF open / close detection sensor (first detection means)
105 Locking claw 106 Solenoid A Hinge part P Bookbinding document KE Equalizing mechanism LE Equalizing lock means

Claims (3)

A document feeding means for feeding a document;
A platen glass for placing the document fed from the document feeding means;
Image reading means for reading an image of a document placed on the platen glass;
A hinge portion that supports the document feeding means so as to be openable and closable with respect to an image reading portion that houses the image reading means, and the document feeding means tilts while rotating about the hinge portion as a fulcrum. The image reading apparatus includes an equalizing mechanism that can move in the vertical direction, and the document feeding unit includes an equalizing lock unit that can selectively lock the equalizing mechanism,
The image reading apparatus includes a detecting unit that detects whether a document placed on the platen glass is a document having a thickness greater than or equal to a predetermined thickness.
An image reading apparatus, wherein when the detecting means detects that the document has a thickness greater than or equal to a predetermined thickness, the equalizing lock means is unlocked. A document feeding means for feeding a document;
A platen glass for placing the document fed from the document feeding means, and an image reading means for reading an image of the document placed on the platen glass;
A hinge portion that supports the document feeding means so as to be openable and closable with respect to an image reading portion that houses the image reading means, and the document feeding means tilts while rotating about the hinge portion as a fulcrum. The image reading apparatus includes an equalizing mechanism that can move in the vertical direction, and the document feeding unit includes an equalizing lock unit that can selectively lock the equalizing mechanism,
The image reading apparatus includes: a first detection unit that detects that an opening / closing angle of the document feeding unit is equal to or less than a predetermined angle with respect to the image reading unit; and a document placed on the platen glass. A second detection means for detecting whether the document has a thickness greater than or equal to a predetermined thickness,
The first detection means detects that the opening / closing angle of the document feeding means is less than a predetermined angle with respect to the image reading unit, and the second detection means is on the platen glass. An image reading apparatus, wherein when it is detected that a placed document is a document having a thickness greater than or equal to a predetermined thickness, the equalizing lock unit is unlocked. Regardless of the detection state of the first detection means, when the second detection means is in the non-detection state (OFF), the equalization lock means is activated to lock the equalization mechanism. The image reading apparatus according to claim 2 .

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