Electrophotography – Document handling
Reexamination Certificate
2002-03-26
2004-06-08
Tran, Hoan (Department: 2852)
Electrophotography
Document handling
C399S377000, C399S379000
Reexamination Certificate
active
06748193
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reader and particularly to a mechanism for retaining a platen glass mounted on a stationary or moving original type image reader in a region where the irradiation of the original is effectuated.
2. Description of the Related Art
An image reader, such as a copying machine or scanner, adapted to read original image data recorded on paper sheet or the like for subsequent various kinds of processing is generally constructed so that the original is irradiated with light beams emitted from a light source lamp such as fluorescent lamp. Light beams reflected on the original are guided to enter a light receiving station provided with a photoelectric converter device such as a CCD (Charge-Coupled Device). In the case of the image reader for a stationary original, for example, like an image scanner as described in Japanese Laid-Open Patent Application No. 1997-330395, the original is placed on the platen glass is irradiated with light beams emitted from said light source lamp which is moved relative to said original. Moving original image readers are also well known, for example, like the image reader disclosed in Japanese Laid-Open Patent Application No. 1996-125806 or the optical scanner disclosed in 1997-179213, in which the original in the course of being fed is irradiated with light beams emitted from a light source lamp placed at a fixed position. It is also well known that the image reader of a stationary original is incorporated with the original feeder mechanism to be used in the stationary original mode as well as in the moving original mode.
An image reader adapted to be used in the stationary original mode as well as in the moving original mode has usually been provided on the lid serving to cover the original placed on the platen glass with the original feeder mechanism. There is provided the light source lamp adapted to be moved to the position at which the original in the course of being fed can be irradiated with light beams emitted from this light source lamp. It is also well known that the one and same image reader is provided with the platen glass exclusively used to read the original in the course of being fed and the platen glass exclusively used to read the stationary original. As the platen glass exclusively used to read the original in the course of being fed, the band-shaped platen glass has usually been used since the original running on this platen glass is irradiated with light beams emitted from the light source lamp.
However, the platen glass exclusively used to read the original in the course of being fed has sometimes been damaged due to its band-like shape. Except when the stationary original is placed on the platen glass, this platen glass is covered and concealed with the lid and, for example, if the user carelessly puts his or her elbow upon the lid and a load exceeding a predetermined value is exerted upon the lid, the platen glass may be flexed and even broken. To avoid such flexion of the platen glass, the platen glass has conventionally been supported on a relatively thick retaining plate.
The moving original runs on the upper surface of the platen glass used to read the original in the course of being fed and, if the original can not smoothly run thereon, it is difficult to read the image recorded on this original at high accuracy. It is also well known to provide above the platen glass original feeding members such as rollers and guide members so that a gap may be ensured between the platen glass and these original feeding members including the guide members appropriate for smooth running of the original.
The original feeding members such as the guide members are mounted on the lid. When the image reader is used in the stationary original mode, after the original has been set on the predetermined position with the lid opened, the image reading is started with the lid closed again to eliminate any effect of ambient light. During operation of setting the original on the predetermined position, the original is sometimes slidably moved on the platen glass. In this case, the original may inconveniently enter the gap possibly defined between the platen glass and the other members such as the glass retaining member. To avoid this inconvenience, the platen glass must be in close contact with the other members such as the glass retaining member.
However, on account of recently increasing demand for improvement in performance as well as compactness of image readers, the conventional mechanism for retaining the platen glass used to read the original in the course of being fed may be accompanied with problems as will be described. To achieve the performance improvement of the image reader, the image recorded on the original must be sharply and clearly reproduced. To this end, it is required that the light source lamp has brightness as high as possible, and the light source lamp is located as closely as possible to the original. If the light source lamp can be placed close to the original, the image reader can be correspondingly thinned and the demand for compactness also can be satisfied. However, with the conventional platen glass retaining plate which is relatively thick, it is difficult or impossible to reduce the distance between the light source lamp and the original and thereby to satisfy the demand for improvement in performance as well as in compactness. Additionally, the relatively thick retaining plate makes weight-saving of the image reader difficult.
To avoid difficulties encountered when that the original might be inserted into a gap between the platen glass and the other members, such as the glass retaining member, it may be contemplated to keep the platen glass in close contact with the glass retaining member. However, a height of the lid on which the guide member is mounted necessarily increases by a dimension corresponding to the gap which should be ensured between the platen glass and the guide member, resulting in that the image reader may become bulky.
SUMMARY OF THE INVENTION
In view of the problems as have been described above, the present invention aims to miniaturize the image reader by improving the platen glass retaining plate used to read the original in the course of being fed so that this retaining plate can be formed as thin as possible. Furthermore, the present invention aims to provide the mechanism for retaining the platen glass exclusively used to read the original in the course of being fed in the image reader improved so that, with the lid opened, the platen glass comes in close contact with the glass retaining member to prevent the original from being inserted between these platen glass and glass retaining member and, with the lid closed, the platen glass is slightly moved downwardly to form an appropriate gap between the platen glass and the guide member of the original feeder and the original can be smoothly fed through this gap.
The object set forth above is achieved, according to one aspect of the present invention, by a mechanism for retaining a platen glass exclusively used to read an original in the course of being fed in an image reader adapted to irradiate said original with light beams from a light source lamp placed at a predetermined position, to pick up light beams reflected on said original and thereby to read an image formed on said original. The mechanism is characterized by said platen glass functioning to guide said original in an appropriately stretched and flattened state in the course of feeding said original retained by retaining means in operative association with a frame of the image reader. The retaining means comprises a glass supporting member having one end on which said platen glass is placed and supported and a member on which the other end of said glass supporting member is placed and supported and which is supported on said frame. Said glass supporting member is formed of a relatively thin plate material and said member to be supported on said frame is formed of a relatively thick plate material
Fuji Photo Optical Co., Ltd.
Price Heneveld Cooper DeWitt & Litton LLP
Tran Hoan
LandOfFree
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