JP2007028515A - Tray latch mechanism for automatic document feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accomplish a tray latch mechanism for an automatic document feeder (ADF) in which a document loading tray is prevented from swinging when the ADF is opened, the tray latch mechanism is surely mounted at a predetermined position while the document loading tray is closed, and a paper feeding property is not affected. <P>SOLUTION: A latch member utilizing gravity is provided at the side of a document loading tray or of an ADF body so that the document loading tray is engaged with the ADF body only when opening the ADF to an image reading apparatus body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a latch mechanism for a document placing tray of an image reading apparatus having an automatic document feeder such as a copying machine or a printer having an image input unit.

  An automatic document feeder (hereinafter referred to as ADF) of an image reading device is a convenient system that allows a plurality of documents to be read by one set without being exchanged in the middle. In general, it is installed directly above the flatbed scanner, and recently it has been installed in small copiers and MFPs. In order to reduce the installation area, the ADF conveyance path is often formed as a U-turn path, and most of the lower part of the document stacking tray is configured as a document discharge portion.

  8 and 9 show two examples of the opening / closing direction of the ADF with respect to the flatbed scanner unit. FIG. 8 is characterized in that there is an open / close hinge in the longitudinal direction of the document, and the depth can be shortened. FIG. 9 has a hinge portion in the short side direction of the document. When the flatbed scanner unit is used in both cases, it is necessary to open the ADF to about 90 ° in order to set the document or the reading object on the document table.

  On the other hand, the ADF will proceed with the explanation when it is assumed that the U-turn path is configured as described above. The document stacking tray needs to be configured to be openable and closable in order to ensure paper handling such as jam processing or taking out small size paper. However, if the ADF is opened carelessly, the document stacking tray may swing out as shown in FIGS. 10 and 11, or it may hit other objects. Therefore, this type of document stacking tray has been provided with a click portion for the ADF main body to prevent inadvertent opening. However, it is quite difficult to set a stable click force for the click portion, not only to cope with the assumed inertial force when the ADF is opened, but also to be securely attached in a predetermined state even when it is closed, for example. This is because the mounting angle of the document stacking tray has an influence on the feedability or the transportability such as skew.

Moreover, as a prior art example, patent document 1 and patent document 2 can be mention | raise | lifted, for example.
Japanese Patent Laid-Open No. 10-319650 JP-A-6-326865

  In view of the above problems, the present invention prevents the document stacking tray from being damaged due to careless opening of the document stacking tray when the ADF is opened, so that the document stacking tray is securely supported by the ADF body, and when the document stacking tray is closed. It is an object of the present invention to realize a tray latch mechanism of an automatic document feeder that can be securely attached to a predetermined position of an ADF main body even with a weak force and can secure ADF sheet feeding and conveyance.

  In order to solve the above problems, the present invention provides an automatic document feeder for an image reading apparatus that also serves as a document pressure plate, and the document loading tray of the automatic document feeder is an automatic document feeder for jam processing and the like. In an image reading apparatus having an automatic document feeder configured to be openable and closable with respect to the feeder main body, the document tray is automatically fed only when the automatic document feeder is opened to the image reader main body. A latch member using gravity is provided on the document placing tray side so as to engage with the apparatus main body. In addition, a latch member using gravity is provided so that the automatic document feeder is engaged with the document tray from the automatic document feeder body only when the automatic document feeder is opened with respect to the image reading apparatus body. It was also provided on the main body side.

  As described above, the automatic document feeder of the image reading apparatus that also serves as a document pressure plate, and the document loading tray of the automatic document feeder opens and closes with respect to the automatic document feeder main body for jam processing and the like. In an image reading apparatus having an automatic document feeder configured so as to be capable of being engaged, the document tray is engaged with the automatic document feeder main body only when the automatic document feeder is opened with respect to the image reader main body. Thus, a latch member using gravity is provided on the document placing tray side. In addition, a latch member using gravity is provided so that the automatic document feeder is engaged with the document tray from the automatic document feeder body only when the automatic document feeder is opened with respect to the image reading apparatus body. It was also provided on the main body side.

  As a result, it has become possible to prevent the document stacking tray from being inadvertently opened when the ADF is opened by a very simple, reliable and inexpensive method, thereby preventing damage to surrounding objects. On the other hand, when the ADF is closed, the document stacking tray can be easily opened, and when the document stacking tray is closed, it is securely attached to the ADF main body at a predetermined position to ensure the ADF paper feedability. be able to.

  An embodiment of a latch mechanism of an image reading apparatus having an automatic document feeder according to the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram illustrating an image forming apparatus according to the present embodiment.
First, an image forming apparatus having a document reading function will be described with reference to FIG.

  As an overall configuration, an image reading device (hereinafter referred to as a scanner unit) 50 is placed, and an automatic document feeder (hereinafter referred to as an ADF unit) 30 is mounted thereon. The automatic document feeder will be described based on a type having a hinge portion on the side in the longitudinal direction as shown in FIG.

  First, the configuration of the ADF will be briefly described. Reference numeral 1 denotes a document stacking tray, and reference numeral 2 denotes a width regulating plate for regulating the side of the document. In order to feed a document by a paper feed roller 3, the document is lowered to the position of the document top surface 3 ′ to pick up the document. Reference numeral 4 denotes a separation roller which always contacts the separation pad 5 which is opposed to each other and performs frictional separation to convey the original one by one. Reference numerals 6 and 6 ′ denote a first conveying roller pair, and reference numerals 7 and 7 ′ denote a second conveying roller pair. Further, Q is a reading point, and an original image passing therethrough is read through the platen glass 51. The document that has passed through the reading unit is discharged to a discharge tray 10 by a discharge roller 8 and a discharge pressure roller 9.

  The scanner unit 50 is provided with an optical reader that reads an image, but the description thereof is omitted here. A platen glass 51 for reading a flatly placed document is mounted on the upper surface of the scanner unit 50, and the ADF unit 30 described above is mounted on the document table so that it can be opened and closed by hinges 11 and 12 to suppress the document. To play a role.

  The document stacking tray portion of the ADF will be described in detail with reference to FIG. The document stacking tray is configured to be rotatable around the rotation shaft 1a, and is rotated when taking out a document discharged to the discharge table 10, particularly a small-sized document, or during jamming of the discharge unit. It improves handling. A latching claw 13 is mounted on the back surface of the document stacking tray 1 so as to be rotatable about the engaging shaft 1b on the back surface of the tray, and is normally lowered in the vertical direction by its own weight. The hook portion 13a at the tip of the locking claw 13 extends to engage with a part of the ADF main body, but when the ADF is closed as a pressure plate, a clearance is provided from the main body portion by Δx in FIG. When the ADF is closed, there is no problem in opening and closing the document stacking tray. However, when the ADF is opened as a pressure plate as shown in FIG. 3, the locking claw 13 falls by its own weight and engages with a part of the ADF main body. Thereby, it is possible to prevent the document stacking tray from being swung inadvertently.

  4 to 5 show a second embodiment. This embodiment is an embodiment in the case where a hinge portion is provided in the short side of the document table as shown in FIG. The engagement shaft 1c is provided in parallel with the tray rotation shaft 1a. Also in this case, when the ADF is closed as shown in FIG. Although this does not cause any trouble, as shown in FIG. 5, when the ADF is opened as a pressure plate, the locking claw 14 falls due to its own weight and engages with a part of the ADF body, causing the document stacking tray to swing unintentionally. Can be prevented.

  A third embodiment is shown in FIGS. As shown in the second embodiment, this embodiment is an embodiment in the case of having a hinge portion in the document table short direction, and is an embodiment in the case where the locking claw 15 is set inside the ADF main body. . Usually, when the ADF is closed, the locking claw 15 falls in the opposite direction to the hook due to its own weight balance, and leans against the wall surface 16 inside the ADF main body. Although the engaging rib 17 extending from the back side of the document stacking tray enters from the hole 18 on the upper surface of the ADF main body, it does not hinder the opening and closing. However, when the ADF pressure plate is opened as shown in FIG. 7, the locking claw 15 falls in the opposite direction and engages with the engaging portion 17a of the engaging rib 17 of the tray.

  Both of the embodiments described above are based on the weight balance of the engaging claws. In order to realize more stable operation of the document stacking tray, it is possible to devise measures such as stabilizing the behavior of the engaging claw by applying a weak spring to the engaging claw so as not to interfere with its own weight balance operation. is there.

Overall configuration diagram of the apparatus according to the first embodiment Explanatory drawing of the main part of the first embodiment Operation explanatory diagram of the first embodiment Explanatory drawing of the main part of the second embodiment Operation explanatory diagram of the second embodiment Explanatory drawing of the main part of the third embodiment Operation explanatory diagram of the third embodiment Conventional example Conventional example Operation explanatory diagram of the conventional embodiment Operation explanatory diagram of the conventional embodiment

Explanation of symbols

30 ADF body 1 Document stacking tray 3 Feed roller 4 Separation roller 6, 6 'First transport roller pair 7, 7' Second transport roller pair 8 Discharge roller 9 Discharge roller
10 Output tray
13 Locking claw
50 Image reader
51 Platen glass

Claims (2)

An automatic document feeder of an image reading device that also serves as a document pressure plate, and a document tray of the automatic document feeder is configured to be openable and closable with respect to the main body of the automatic document feeder for jam processing. In an image reading apparatus having an automatic document feeder,
Only when the automatic document feeder is opened with respect to the image reading apparatus main body, a latch member using gravity is provided on the side of the original document tray so that the document placing tray engages with the automatic document feeder main body. A tray latch mechanism of an automatic document feeder characterized by being provided. An automatic document feeder of an image reading device that also serves as a document pressure plate, and a document tray of the automatic document feeder is configured to be openable and closable with respect to the main body of the automatic document feeder for jam processing. In an image reading apparatus having an automatic document feeder,
Only when the automatic document feeder is opened to the image reading apparatus main body, the latch member using gravity is engaged with the original document tray from the automatic document feeder main body. A tray latch mechanism of an automatic document feeder characterized by being provided on the side.

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