Image reading apparatus having a flexible flat cable

An image reading apparatus includes a platen on which a document is placed, an image reading unit configured to be movable under the platen, to receive light reflected by the document placed on the platen, and to output an image signal, a flexible flat cable configured to transfer the image signal output from the image reading unit, and a holding member configured to hold the flexible flat cable and attached to the image reading unit. The image reading unit includes a connection portion to which the flexible flat cable is connected, and, when the image reading unit is moved, a curvature portion of the flexible flat cable is formed opposite the connection portion across the image reading unit in a direction in which the image reading unit is moved.

BACKGROUND

Aspects of the present invention generally relate to an image reading apparatus using a flexible flat cable.

2. Description of the Related Art

A conventionally known image reading apparatus is described below with reference toFIGS. 9 and 10.

Within a frame member901of an image reading apparatus, an image reading unit902reciprocally movable inside the frame member901is provided. The image reading unit902is provided with a sensor substrate into which an image sensor such as a charge coupled device (CCD) is incorporated, an illumination unit for illuminating a document image, and a lens for performing imaging of light reflected from a document onto the image sensor. The image reading unit902reads the document laid on a document positioning glass plate903while moving under the document positioning glass plate903.

The image reading unit902is reciprocally moved by a driving force of a motor arranged in the frame member901. In the specification, a direction in which the image reading unit902is reciprocally moved is called a sub-scanning direction and a direction orthogonal to the sub-scanning direction (the longitudinal direction of the image reading unit902) is called a main-scanning direction.

InFIG. 9, a sensor substrate is provided on the right of the image reading unit902.FIG. 10illustrates a perspective view of the image reading unit902drawn from a view point where a sensor substrate1003and a flexible flat cable904(hereinafter referred to as an FFC) can be observed.

The image reading apparatus includes a controller substrate (not illustrated) for providing a motor with a control signal to move the image reading unit902and for processing the image signal output from the image reading unit902.

The image reading unit902is connected to the controller substrate by the FFC904to perform communication using the control signal and the image signal between the controller substrate and the image reading unit902. One end of the FFC904is connected to the sensor substrate1003of the image reading unit902.

InFIG. 9, a curvature portion1001of the FFC904is provided at the left of the image reading unit902to prevent the FFC904from being buckled when the image reading unit902is reciprocally moved, allowing the image reading unit902to be smoothly moved.

In a conventional technique, guide portions1002for guiding the FFC904are provided on the bottom surface of the image reading unit902. Part of the FFC904connected to the sensor substrate1003is held by the guide portions1002on the bottom surface of the image reading unit902and the FFC904is guided to the left of the image reading unit902inFIG. 9. InFIG. 9, the curvature portion1001of the FFC904is formed at the left of the image reading unit902in the sub-scanning direction.

The conventional image reading apparatus, however, has to-be-solved problems of workability in attaching and detaching the FFC to and from the image reading unit902.

Since the workability in attaching and detaching the FFC to and from the conventional image reading apparatus is poor, wrinkles and scratches may be made during the operation in which the FFC is guided by the guide portions. The wrinkles and scratches may cause breaking of the wires of the FFC.

SUMMARY

According to an aspect of the present invention, an image reading apparatus includes a platen on which a document is placed, an image reading unit configured to be movable under the platen, to receive light reflected by the document placed on the platen, and to output an image signal, a flexible flat cable configured to transfer the image signal output from the image reading unit, and a holding member configured to hold the flexible flat cable. The image reading unit includes a connection portion to which the flexible flat cable is connected, and, when the image reading unit is moved, a curvature portion of the flexible flat cable is formed opposite the connection portion across the image reading unit in a direction in which the image reading unit is moved.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects will be described in detail below with reference to the drawings. An exemplary embodiment described below is not to be seen to limit the technical scope of the present disclosure.

A general configuration of an image reading apparatus202according to the present exemplary embodiment is described below with reference toFIGS. 2, 3, and 4. The image reading apparatus202is merely an example and additional embodiments can also be applied to a facsimile apparatus or a multifunction peripheral equipped with the image reading apparatus202.

FIG. 2is a schematic diagram illustrating the image reading apparatus202equipped with an automatic document feeding apparatus201(hereinafter referred to as an ADF).FIG. 3is a schematic diagram illustrating the image reading apparatus202with the ADF201opened.

As illustrated inFIG. 2, the ADF201is attached to the upper portion of the image reading apparatus202. The ADF201includes a paper feed tray203on which a plurality of documents can be laid. The documents laid on the paper feed tray203are separated one by one, conveyed to an image reading position, and discharged to a discharge tray204. The document is read by an image reading unit401laying under the image reading position while being conveyed (hereinafter referred to as “reading during conveyance”).

As illustrated inFIG. 3, the ADF201can be opened with respect to the image reading apparatus202. A platen301is formed of a transparent member such as glass. The ADF201is opened with respect to the image reading apparatus202to allow a document or a thick document (a book, for example) to be laid on the platen301. The ADF201is closed with respect to the image reading apparatus202to press the document laid on the platen301by a pressing plate302provided on the bottom surface of the ADF201. The image reading unit401moves under the platen301in the sub-scanning direction to read the document laid on the platen301(hereinafter referred to as “fixed-reading”).

FIG. 4is a cross section illustrating the image reading apparatus202. The image reading unit401is arranged inside a frame member402and reciprocally movable in a sub-scanning direction403. The image reading unit401includes an illumination unit such as a light emitting diode (LED) for illuminating a document in an image reading position, an image sensor such as a CCD, a sensor substrate404into which the image sensor is incorporated, and an optical lens for performing imaging of light reflected from the document onto the image sensor. InFIG. 4, the sensor substrate404is fixed to the right of the image reading unit401in the sub-scanning direction403. The image sensor receives light reflected from the document illuminated by the illumination unit to generate an image signal. The image reading unit401outputs the generated image signal. The image reading unit401includes a controller substrate (not illustrated) for providing a control signal to a motor to move the image reading unit401and for processing the image information output from the image reading unit401. The image reading unit401is connected to the controller substrate by a flexible flat cable (FFC)102to communicate therebetween using the control and image signals. One end of the FFC102is connected to a connection portion103of the sensor substrate404and the other end is connected to the controller substrate. The image information output from the sensor substrate404of the image reading unit401is transferred to the controller substrate via the FFC102, and then the information is processed.

A positional relationship between the image reading unit401and the FFC102is described below. InFIG. 4, the sensor substrate404is fixed to the right of the image reading unit401in the sub-scanning direction, so that the FFC102and the connection portion103of the sensor substrate404are also provided on the right of the image reading unit401in the sub-scanning direction inFIG. 4.

The FFC102connected to the connection portion103is guided to the other side of the image reading unit401in the sub-scanning direction via the bottom surface of the image reading unit401so as not to prevent the reading of an image. A curvature portion106needs to be provided to prevent the FFC102from being buckled when the image reading unit401is reciprocally moved in the sub-scanning direction403.

In the conventional technique illustrated inFIG. 10, the FFC904is attached to the bottom surface of the image reading unit902using the guide portions1002provided on the bottom surface of the image reading unit902. On the other hand, in the present exemplary embodiment, the FFC102is attached to the image reading unit401using a holding member101.FIG. 1is a schematic diagram illustrating the holding member101.

The FFC102is attached to the holding member101using a double-faced tape. The holding member101to which the FFC102is attached is attached to the image reading unit401using a claw portion104and a snap fit portion105.

The use of the simply attachable holding member101eliminates the need for the worker of guiding the FFC to the guide portions1002provided on the bottom surface of the image reading unit, which is performed when the conventional apparatus illustrated inFIG. 10is assembled. This can prevent wrinkles and scratches from being made in the work for guiding the FFC to the guide portions1002. More specifically, the use of the holding member101can prevent the FFC from being damaged in the assembly work and can readily attach the FFC to the image reading unit401.

A positional relationship between the claw portion104and the snap fit portion105of the holding member101is described below with reference toFIGS. 1 and 5.FIG. 5is a schematic diagram illustrating an operation for attaching the holding member101to the image reading unit401.

An FFC end108is an end of the FFC102connected to the connection portion103of the image reading unit401. The claw portion104of the holding member101is provided on the same side as the FFC end108. The snap fit portion105of the holding member101is provided on the opposite side of the claw portion104. On the opposite side of the claw portion104, the curvature portion106of the FFC is also provided.

The claw portion104and the snap fit portion105are thus arranged to enable the holding member101to be readily attached and detached, irrespective of whether the FCC end108is connected to the connection portion103.

When the holding member101is attached to the image reading unit401, a worker first hooks the claw portion104on a predetermined place of the image reading unit401. Thereafter, as indicated in a holding member rotation direction501, the holding member101is rotated to fit the snap fit portion105on the predetermined place of the image reading unit401. The worker allows the holding member101to be attached to the image reading unit401. The snap fit portion105is provided on the side of the curvature portion106of the FFC to prevent the holding member101from being pulled by the FFC even when the holding member101is rotated as indicated in the holding member rotation direction501.

When the holding member101is detached from the image reading unit401, the worker first detaches the snap fit portion105from the image reading unit401. Thereafter, the holding member101is rotated as indicated in the holding member rotation direction501, and then the claw portion104is detached from the image reading unit401. Since the claw portion104is provided on the same side as the FCC end108, a positional relationship between the FCC end108and the connection portion103of the image reading unit401can be maintained until the holding member101is detached from the image reading unit401. In other words, even if the FCC end108is connected to the connection portion103, the holding member101can be detached from the image reading unit401. Since the FCC end108can be detached from the connection portion103after the holding member101is detached, the FCC end108can also be easily detached. The possibility can be reduced that a large force used in detaching the snap fit portion105from the image reading unit401may be applied to the connection portion103and that the FCC end108and the connection portion103may be damaged.

FIGS. 6A and 6Bare diagrams in which the holding member101attached to the image reading unit401arranged in the frame member402of the image reading apparatus202is viewed from the side of the platen301. InFIGS. 6A and 6B, the curvature portion106of the FFC102, a folding portion605inside the holding member101, and a portion604except a folding portion are illustrated with reference numerals.

As illustrated inFIG. 6B, there are arranged a frame member402of the image reading apparatus202, the image reading unit401, the FFC, and an image reading area602(or, area of the platen301). If the FFC contacts the platen301, foreign matters such as dust may adhere to the platen301, and this can degrade image quality. In the present exemplary embodiment, as illustrated inFIG. 6A, the FFC connected to the connection portion103of the image reading unit401arranged inside the image reading area602is displaced to the outside of the image reading area602in the main scanning direction603using the holding member101. The main scanning direction603is the direction orthogonal to the sub-scanning direction403. More specifically, the FFC is folded twice inside the holding member101to arrange the curvature portion side of the FFC604on the outside of the image reading area602. The position of the curvature portion side of the FFC106is displaced by a predetermined distance601in the main scanning direction with respect to the position of the connection portion side of the FFC. Thus, the FFC outside the holding member101(i.e., the FFC curvature portion106and the FFC except a folding portion604) can be arranged outside the image reading area602, thus preventing the FFC from contacting the platen301.

The following describes how effective a holding portion107is provided on the holding member101.FIGS. 7 and 8are schematic diagrams illustrating how the reciprocal movement of the image reading unit401in the sub-scanning direction affects the curvature portion701of the FFC102by the presence or absence of the holding portion107.

The holding member101of the present exemplary embodiment illustrated inFIG. 7includes the holding portion107extending toward the platen301. The FFC extending from the bottom surface of the image reading unit401is folded upward (toward the platen301) by the holding portion107.

As illustrated inFIG. 8, a holding member not including the holding portion107may be used from the viewpoint of workability at the time of assembling the FFC. However, it is effective to use the holding member101including the holding portion107to increase a durability life of the FFC.

As illustrated inFIGS. 7 and 8, when the image reading unit401reciprocally moves in the sub-scanning direction403, the curvature portions701and801are formed on the FFC. As illustrated inFIG. 7, when the holding portion107is provided, the curvature portion701has a curvature angle702. As illustrated inFIG. 8, when the holding portion107is not provided, the repetitive curvature portion801has a curvature angle802. If the curvature angle is greater when the image reading unit401reciprocally moves, the repetitive fatigue caused on the curvature portion becomes greater. As is clear fromFIGS. 7 and 8, the curvature angle702is smaller than the curvature angle802. Consequently, the holding portion107is provided to reduce the fatigue caused on the curvature portion, and this can increase the durability life of the FFC.

While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that these embodiments are not limiting. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2012-177087 filed Aug. 9, 2012, which is hereby incorporated by reference herein in its entirety.