JPH05268426A - Scanning body structure for picture reader - Google Patents

Abstract

PURPOSE:To realize miniaturization of the reader and thin profile without losing advantages of non-magnification image forming elements and to obtain the structure of scanning body of the picture reader with high accuracy and an inexpensive carriage scanning mechanism. CONSTITUTION:Part of a carriage main body 3 is in press contact with a rear side of a contact glass by pressing elastically each of carriage guide members 18, 19 by three pressing rollers supported movably and turnably with respect to a carriage main body 3. Thus, the optical distance of the scanner 2 with respect to the original placing face is kept constant and the carriage main body 3 is subjected to scanning drive by the carriage drive means arranged on both sides in the main scanning while being guided by one moving restriction roller 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning member structure of an image reading section in an image reading apparatus such as a copying machine and a facsimile.

[0002]

2. Description of the Related Art A type of image reading apparatus such as a copying machine or a facsimile apparatus in which a document surface placed on a contact glass of a document table is scanned by a scanner which moves along the back surface of the contact glass. It has been known. Here, the scanner is generally configured to scan the document surface by being mounted on a carriage body that is reciprocally driven by a wire or the like along the back surface of the contact glass. As a conventional technique related to the structure of the scanning body including the scanner and the carriage body, Japanese Patent Laid-Open No. 1-29373 is known.
The "document reading device" described in Japanese Patent Laid-Open No. H55-293756 and Japanese Patent Laid-Open No. 1-293756 is known. Each of the scanning bodies in these conventional "original reading devices" has four light friction members (bearings) that come into contact with the contact glass, a carriage body that holds a sensor and an illumination member, and this carriage body as the contact glass. It is composed of a spring member (a leaf spring or a coil spring) to be pressed, and a carriage holding member that holds a carriage body and has a bearing portion guided by a central guide shaft.

[0003]

By using an equal-magnification image forming element as a scanner of a scanning body in an image reading apparatus such as a copying machine or a facsimile, the optical system can be simply constructed, and the image can be formed easily. The reading device can be made smaller and thinner. In order to realize such a small and thin image reading apparatus, it is necessary to make the structure of the scanner itself as well as the scanner thin. However, in the structure of the scanning body in the conventional "document reading apparatus", the guide shaft for holding the carriage body and the driving member including the pulley and the belt for driving the carriage body are provided at the central portion of the apparatus body. Since it is arranged so that
The height of the scanning body becomes the size of the height of the carriage body and the height of the driving member, and there is a problem that it becomes difficult to reduce the thickness of the apparatus main body below this height.

Further, in the scanning body structure in the conventional "document reading apparatus", since the guide of the carriage body is guided by the guide shaft and the bearing member, the play between the guide shaft and the bearing member is caused. The carriage body is structured to easily move in the main scanning direction (sensor arrangement direction). Therefore, in the conventional scanning body structure, when used as a scanning body of a color copying machine, a color printer, or the like that requires three reading operations for one document, the carriage for each reading operation is The original reading position on the body does not always match,
There is a problem that misalignment (color misregistration) occurs in the read image.

The problem caused by the fine movement of the carriage body in the main scanning direction is caused by the structure of the scanning body of the "image reading device" described in Japanese Patent Application Laid-Open No. 2-213268 previously proposed by the present applicant. It can be eliminated by adopting it. That is, in the scanning body structure of this "image reading device", the carriage body is guided by the movement restricting roller having the V-shaped peripheral surface and the guide shaft, so that the carriage body is scanned in the main scanning direction. The movement of the carriage is regulated to prevent the carriage from being displaced when the image is read. However, since the movement restricting roller in this conventional “image reading device” is composed of a single body, when the carriage body is extremely inclined with respect to the guide shaft, the V groove of the movement restricting roller and the guide shaft are "Galling" or "single contact" is likely to occur between them, and the frictional resistance between the V groove of the movement restricting roller and the guide shaft is extremely increased to prevent the rotation of the movement restricting roller or to make the rotation heavy. Had a problem that became.

The present invention has been made in view of the above points, and an object of the present invention is to realize downsizing and thinning of a device without impairing the advantages of the same-magnification imaging element. It is an object of the present invention to provide a scanning body structure of an image reading apparatus with a carriage scanning mechanism that is inexpensive and highly accurate.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a contact glass on which a document is placed, and a scanner arranged on the back side of the contact glass along the main scanning direction. A carriage body that supports the
Two carriage guide members arranged substantially parallel to each other in the sub-scanning direction on both sides of the carriage body in the main scanning direction, and one carriage guide member rotatably supported by the carriage body. One movement regulation roller that is regulated in contact with the movement in the main scanning direction and is in contact with the carriage body so as to be displaceably and rotatably supported by the carriage body, and elastically presses each of the carriage guide members. Are arranged on both sides of the carriage body in the main scanning direction, and three pressing rollers for keeping a constant optical distance to the original placement surface of the scanner by bringing a part of the carriage body into contact with the carriage body. And a carriage driving means.

Further, in order to solve the above-mentioned problems, the present invention comprises a carriage guide member on the side on which the movement restricting roller comes into contact with a shaft-like member, and the movement restricting roller comes into contact with the carriage guide member. The surface is formed in a V-groove shape by the peripheral surfaces of a pair of umbrella-shaped rollers that are rotatably supported independently of each other.

[0009]

According to the present invention, each of the carriage guide members is elastically pressed by the three pressing rollers movably and rotatably supported with respect to the carriage body, and the carriage is attached to the back surface of the contact glass. By abutting a part of the main body, the optical distance with respect to the original placement surface of the scanner is kept constant, and the carriage main body is scanned by the carriage driving means arranged on both sides in the main scanning direction. Driven.

Further, according to the present invention, the main scanning of the carriage main body with respect to the two carriage guide members arranged substantially parallel to each other in the main scanning direction on both sides of the carriage main body supporting the scanner is performed. The positional deviation in the direction is prevented by a single movement restricting roller that is rotatably supported by the carriage main body and that abuts against the one carriage guide member with its movement in the main scanning direction restricted. Further, according to the present invention, the carriage guide member on the side where the movement regulating roller comes into contact is constituted by a shaft-shaped member, and the contact surface of the movement regulating roller with respect to the carriage guide member is rotatable independently of each other. By forming the V-shaped groove by the peripheral surfaces of the pair of umbrella-shaped rollers pivotally supported by the carriage body, the carriage body is moved smoothly.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. However, for the sake of avoiding complication of the description, the illustration and disclosure of the configurations and operations within the scope that can be clearly recalled from the description of the present specification, and the above and other objects and novel features of the present invention are omitted. , Or simplify.

FIG. 1 shows a schematic structure of a scanning body of the image reading apparatus of the present invention. This scanning body is shown in FIGS.
As shown in FIG. 3, a contact glass 7 on which a document (not shown) is placed, and a scanner arranged along the main scanning direction (direction orthogonal to the paper surface of FIG. 2) on the back side of the contact glass 7. 2 and two carriage guide members 18, 19 arranged substantially parallel to each other in the sub-scanning direction (left and right direction in FIG. 2) on both sides of the carriage main body 3 in the main scanning direction. And the carriage body 3
One carriage guide member 18 rotatably supported by
A movement regulation roller 8 which is regulated in contact with the main scanning direction to abut, and each carriage guide member 18, which is movably and rotatably supported with respect to the carriage body 3.
By elastically pressing 19 to bring a part of the carriage body 3 into contact with the back surface of the contact glass 7, the optical distance of the scanner 2 with respect to the document mounting surface is kept constant 3
The pressure roller 10 and the carriage driving means (see FIG. 7) arranged on both sides of the carriage body 3 in the main scanning direction.

Here, in FIG. 1, in order to facilitate the description, the fluorescent lamp 6 and the CCD drive circuit board 19 which are originally mounted as shown in FIG. 2 are omitted. 2 is a schematic cross-sectional view of the scanning body as viewed in the direction of arrow A in FIG. 1, and FIG. 3 is a side view of the scanning body as viewed in the direction of arrow B in FIG.

1 to 3, the scanner 2 of this embodiment is composed of an equal-magnification imaging element 11 (selfoc lens) and an equal-magnification sensor 17, and is integrated with the carriage body 3 by a holding member 2a. Has been done. Rotating rollers 1 abutting on the back surface of the contact glass 7 are rotatably supported on both sides of the holding member 2a in the main scanning direction. The rotating roller 1 is composed of, for example, a light friction member such as a bearing, and the carriage body 3 can be extremely easily attached to the contact glass 7 in a state where the peripheral surface of the rotating roller 1 contacts the back surface of the contact glass 7. It works so that you can move.

On the traveling direction side (left side in FIG. 2) of the carriage main body 3, the image signal from the same-size sensor 17 is transmitted to a main body control board (not shown), or conversely, is supplied from the main body side. Electric power (electric power for driving the fluorescent lamp 6 and the same-size sensor 17)
A flexible substrate 5 and a substrate supporting member 4 for transmitting the power are attached.

On the other hand, as shown in FIG. 1, the carriage main body 3 is rotatably supported, and one of the carriage guide members 18 is brought into contact with a peripheral surface formed in a V-groove shape to bring the carriage into contact. One movement regulation roller 8 configured to regulate the movement of the main body 3 in the main scanning direction.
As shown in FIG. 4, the carriage guide member 18 on the side with which the movement restricting roller 8 abuts is composed of a shaft-like member, and the contact surface of the movement restricting roller 8 to the carriage guide member 18 is the bearing member 8a. A pair of left and right umbrella-shaped rollers 8A and 8B, which are rotatably supported independently of each other by (press-fitting) and spacer 8b, are formed in a V-groove shape. Therefore, according to the movement regulating roller 8 of the present embodiment, the peripheral surfaces of the rollers 8A and 8B can independently contact and rotate with respect to the carriage guide member 18, so that, for example, the wire 15 of the carriage driving means.
When the carriage body 3 is extremely inclined with respect to the guide shafts (carriage guide members 18 and 19) or is not at a right angle due to the elongation of the roller, "galling" occurs between the V groove of the movement restricting roller 8 and the guide shaft. The problem that "the one-side contact" occurs and the frictional resistance between the V groove of the movement regulating roller 8 and the guide shaft is extremely increased, the rotation of the movement regulating roller 8 is blocked or the rotation becomes heavy is solved. it can.

On the other hand, each pressing roller 10 in the present embodiment.
As shown in FIGS. 5 and 6, each arm member 9, 1
The free ends 2 and 13 are rotatably supported respectively. Each of the pressing rollers 10 has a flat peripheral surface, and does not have the function of restricting the movement of the carriage body 3 in the main scanning direction like the above-described movement restricting roller 8. , Each carriage guide member 1
8 and 19 are elastically contacted with each other. The contact elastic force of each pressing roller with respect to each carriage guide member 18, 19 is, as shown in FIGS. 1 to 3, each arm member 9, 12, 13 and these arm members 9, 19.
It is provided by coil springs 9a and 12a and a torsion spring 13a which are hung between the carriage main body 3 which swingably supports 12 and 13, respectively. As a result, in the carriage main body 3 of the present embodiment, the peripheral surface of each rotating roller 1 described above becomes the back surface of the contact glass 7 due to the contact force of the above-mentioned three pressing rollers 10 with each carriage guide member 18, 19. Contact glass 7 until contact
Is pushed up to the back surface side, and the optical distance with respect to the document mounting surface of the scanner 2 is maintained constant. Here, of the two carriage guide members 18 and 19, the carriage guide member 19 on the side where the above-mentioned movement regulating roller 8 does not come into contact.
Is composed of a plate-shaped member. In this way, the carriage body 3 is supported by the one movement regulating roller 8 and the three pressing rollers 10, and one carriage guide member 19 is provided.
Is a plate-shaped member, the load during the operation of the carriage body 3 can be made extremely small, and it is not necessary to maintain the parallelism of the carriage guide members 18 and 19 with high accuracy. It is possible to reduce the size, increase the moving speed of the carriage body 3, and reduce the cost of the apparatus.

On the other hand, the carriage driving means of this embodiment is
As shown in FIG. 7, the motor pulley 14 of the drive motor 14
The carriage main body 3 is clamped to both sides of the carriage main body 3 in the main scanning direction between the wires 15 which are wound around the four pulleys 16 and driven to reciprocate by a. It is configured to move back and forth.

[0019]

According to the present invention, the load during the operation of the carriage body 3 can be made extremely small, and it is not necessary to maintain the parallelism of the carriage guide members 18 and 19 with high accuracy, and the drive motor 14 can be used. Can be downsized, the moving speed of the carriage body 3 can be increased, the cost of the device can be reduced and the device can be made thin, and the stability and reliability during operation can be improved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a structure of a scanning body of an image reading apparatus of the present invention.

FIG. 2 is a schematic cross-sectional view of the structure of the scanning body of the image reading apparatus of the present invention seen from one side surface.

FIG. 3 is a schematic side view of the structure of the scanning body of the image reading apparatus of the present invention as seen from the other side surface.

FIG. 4 is a schematic cross-sectional view of a movement regulation roller in the scanning body structure.

FIG. 5 is a perspective view showing a support structure of a pressing roller in the scanning body structure.

FIG. 6 is a perspective view showing a supporting structure of another pressing roller in the scanning body structure.

FIG. 7 is a schematic perspective view showing drive means of a carriage body in the above-described scanning body structure.

[Explanation of symbols]

 1 Rotating Roller 2 Scanner 3 Carriage Main Body 7 Contact Glass 8 Movement Restricting Roller 9, 12, 13 Arm Member 10 Pressing Roller 14 Drive Motor 15 Wire 16 Pulley 18, 19 Carriage Guide Member

Claims (5)

[Claims] 1. A contact glass on which a document is placed, a carriage main body supporting a scanner arranged along the main scanning direction on the back side of the contact glass, and both side portions of the carriage main body in the main scanning direction. Two carriage guide members arranged substantially parallel to each other in the sub-scanning direction, and rotatably supported by the carriage body, and restricted from moving in the main scanning direction with respect to the one carriage guide member. One movement regulating roller that abuts and one that is rotatably supported with respect to the carriage body and elastically presses each of the carriage guide members to abut a part of the carriage body on the back surface of the contact glass. By doing so, three pressing rollers that maintain a constant optical distance to the original placement surface of the scanner, and main scanning of the carriage body. Scan structure of the image reading apparatus characterized by comprising a carriage drive means disposed on both sides site countercurrent. 2. A carriage guide member of the two carriage guide members, which is in contact with the movement regulating roller, is formed of a shaft-like member, and a contact surface of the movement regulating roller with respect to the carriage guide member is V. The scanning body structure of the image reading apparatus according to claim 1, wherein the scanning body structure is formed in a groove shape. 3. A carriage guide member on the side on which the movement regulating roller abuts is constituted by a shaft-like member, and a contact surface of the movement regulating roller on the carriage guide member is rotatably supported independently of each other. The scanning body structure of the image reading apparatus according to claim 1, wherein the pair of umbrella-shaped rollers are formed into a V-groove shape by the peripheral surfaces thereof. 4. The scanning of the image reading apparatus according to claim 1, wherein the carriage guide member of the two carriage guide members which is not in contact with the movement regulating roller is constituted by a plate member. Body structure. 5. The three pressing members are pressed against respective end portions of three arm members which are urged in a direction approaching the two carriage guide members and swingably arranged on the carriage body. 2. The scanning member of the image reading apparatus according to claim 1, wherein the rollers are pivotally supported so that the three pressing rollers are brought into contact with the two carriage guide members without restriction. Construction.