JP4147586B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus including an original reading unit that moves a one-carriage scanning body including a light source, a mirror, a lens, a CCD base, and the like to read an image of an original.

  A conventional image reading apparatus including a one-carriage-type original reading unit includes a box-shaped housing having an upper surface opened. A platen glass made of transparent glass is disposed on the upper surface of the housing. A scanning body is arranged inside the housing so as to be movable in the scanning direction along the lower surface of the platen glass. This scanning body includes a light source, a mirror, a lens, a CCD base, a position detection sensor, and the like. Further, a stepping motor for reciprocating the scanning body in the longitudinal direction of the document and a drive shaft and a belt for transmitting a driving force for moving the scanning body from the stepping motor to the scanning body are disposed inside the casing. .

According to the image reading apparatus, the driving force of the stepping motor is transmitted to the belt via the drive shaft. The scanning body is transmitted a driving force by the belt and is moved in the scanning direction along the lower surface of the platen glass from the start position.
Further, the scanning body irradiates light from the light source on the image surface of the document on the platen glass from below the platen glass while moving. At the same time, the scanning body reflects the reflected light received from the document through a plurality of mirrors, and forms an image of this light toward the CCD substrate by the lens. The CCD board converts the optical signal into an electrical signal, and the image of the original is read.
After the image reading of the document is completed, the scanning body is moved in the direction of the start position. When the scanning body reaches the start position and the start position is detected by the position detection sensor, the stepping motor is stopped and the scanning body is stopped at the start position.

JP 2001-5121 A JP 2002-236327 A

By the way, the CCD substrate of the image reading apparatus is an important component that greatly affects the image reading quality. In the one-carriage scanning body, the CCD substrate is provided on the side wall of the scanning body.
Therefore, when trouble such as a position detection sensor failure or stepping motor control failure occurs at the end of scanning of the scanning body or when moving to the start position, the scanning body continues to move without stopping at the start position. There is a problem that the CCD substrate provided on the side wall collides with the casing and the position of the CCD substrate is shifted.

  In view of the above circumstances, the present invention provides an image reading apparatus capable of preventing the CCD base, which is an important component, from colliding with the housing even when the scanning body does not stop at the planned stop position due to a failure or the like. The purpose is to do.

According to the first aspect of the present invention, a box-shaped housing having an open top surface, a document placing table provided on the top surface of the housing, and a document placing table provided inside the housing are placed on the document placing table. An image reading apparatus comprising: a scanning body that irradiates light on a document and reads an image of the document; and an imaging unit that converts an optical signal into an electrical signal is provided on one side wall of the scanning body in a moving direction. And a rib is provided on one side wall of the casing facing the side wall on which the imaging unit of the scanning body is provided, and the length of the rib is longer than the protruding length of the imaging unit from the side wall. And the rib is in contact with the side wall to prevent the imaging means from contacting the casing .

  According to the first aspect of the present invention, the document is placed on the document placing table on the upper surface of the casing with the image surface of the document facing the scanning body, and the scanning body is moved in the longitudinal direction of the document in parallel with the document. Light is irradiated from the scanning body onto the image surface of the document, and reflected light reflected from the document enters the imaging means. In the image pickup means, the optical signal is converted into an electric signal and an image of the original is read. After reading the original image, the scanning body is moved in the direction of the start position. When the scanning body reaches the start position, the scanning body is stopped. At this time, even if the scanning body does not stop due to a failure of the scanning body position detection sensor, control failure, etc., and the scanning body continues to move beyond the start position where it was scheduled to stop, the rib length is imaged. Since the protrusion length of the means from the scanning body is longer, the rib comes into contact with the scanning body before the imaging means collides with the housing, and further movement of the scanning body is restricted.

According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the scanning body moves along a guide rod penetrating the scanning body, and the rib is formed from the bottom of the housing. The rib is provided to extend toward the guide rod, and the height of the rib from the bottom of the housing is higher than the height of the guide rod from the bottom of the housing.

According to invention of Claim 2 , the height from the bottom part of a rib is set so that it may become higher than the height in which the guide rod is arrange | positioned. Thereby, even when the scanning body and the rib collide, the posture of the scanning body can be stabilized.

According to the first aspect of the present invention, when the scanning body does not stop due to a failure of the position detection sensor of the scanning body, control failure, etc., and the scanning body continues to move beyond the start position where the scanning was scheduled to stop. However, when the rib provided on the casing comes into contact with the scanning body, it is possible to prevent the imaging means from colliding with the casing.

According to invention of Claim 2 , the height from the bottom part of a rib is set so that it may become higher than the height in which the guide rod is arrange | positioned. Thereby, even when the scanning body and the rib collide, the posture of the scanning body can be stabilized.

Next, an image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 3, the image reading apparatus 10 includes a box-shaped housing 12 whose upper surface is open. A platen glass 16 (original placement table) made of transparent glass is disposed on the upper surface 14 of the housing 12.
In the housing 18, a guide rod 20 for guiding the document reading unit 26 and a guide rail 24 having a sliding plane 22 with the document reading unit 26 on the upper surface are parallel to the platen glass 16. Is arranged.

  Here, the document reading unit 26 receives a scanning body 28 described later, a light source 38 described later that irradiates light on the document P placed on the platen glass 16, and a CCD base 54 (imaging unit) described later from the document P. Reflected light guided by the first mirror 42, the second mirror 44, the third mirror 46, and the fourth mirror 48 for guiding the reflected light, and the first to fourth mirrors 42, 44, 46, 48. A lens 50, which will be described later, and a CCD substrate 54, which will receive light from the lens 50 and convert an optical signal into an electrical signal, are configured.

The scanning body 28 is arranged so as to extend in a direction perpendicular to the scanning direction (arrow X direction side in FIGS. 1 and 2).
A guide rod 20 penetrates in the vicinity of one end of the scanning body 28 in the width direction. Further, the bottom 32 near the other end in the width direction of the scanning body 28 is brought into contact with the sliding plane 22 of the guide rail 24 so as to be movable in the scanning direction (arrow X direction side in FIGS. 1 and 2). ing.
As a result, the scanning body 28 can move in the scanning direction (in the direction of arrow X in FIGS. 1 and 2) in a state parallel to the platen glass 16.

As shown in FIGS. 2 and 3, a slit wall 36 is formed on the upper surface of the scanning body 28. The slit wall 36 is formed with a slit 34 that extends in the longitudinal direction of the slit wall 36 and guides reflected light to the inside 40 of the scanning body. A light source 38 is provided on the upper surface of the slit wall 36.
A first mirror 42, a second mirror 44, a third mirror 46, and a fourth mirror 48 are provided in the scanning body interior 40, respectively. A lens 50 is provided on the path L of the reflected light from the document P.
On one side wall 52 of the scanning body 28 extending in a direction perpendicular to the return direction of the scanning body 28 (arrow Y direction side in FIG. 3), a part of the CCD base 54 is exposed to the outside of the scanning body 28. It is provided in the state.
In addition, a position detection sensor 60 for detecting a stop position S corresponding to a start position of the scanning body 28 is disposed on the bottom 56 of the scanning body 28 toward the opposite housing bottom 58. Further, a detection piece 62 detected by the position detection sensor 60 is arranged on the housing bottom 58.

As shown in FIGS. 1 and 2, a stepping motor 64 as a drive source for reciprocating the scanning body 28 is disposed near one end of the guide rod 20 inside the housing 18. A driving shaft 66 for transmitting a driving force is connected to the stepping motor 64. A pulley 68 is fixed to the drive shaft 66.
A driven pulley 70 is rotatably disposed near the other end of the guide rod 20. Further, a belt 74 is wound around the pulley 68 and the driven pulley 70 to which the driving force is transmitted. The scanning body 28 is fixed to a part of the belt 74.

As shown in FIGS. 1 to 3, a harness path 76 for allowing the harness H to pass through a path wall 80 erected from the bottom 58 of the casing 12 is formed in the casing interior 18. The path wall 80 is formed in parallel along one end surface of the housing 12 that faces the side wall 52 of the scanning body 28.
A part of the path wall 80 is integrally formed with a collision preventing rib 78 (protective member, protruding portion) protruding toward the scanning body 28. The protruding length LR of the rib 78 from the path wall 80 is set to be longer than the protruding length LC of the CCD base 54 protruding from the scanning body 28 from the scanning body 28.
The height of the rib 78 from the bottom 58 is set to be higher than the height at which the guide rod 20 is disposed. Thereby, even when the scanning body 28 and the rib 78 collide, the posture of the scanning body 28 can be stabilized.

Next, the operation of the image reading apparatus 10 according to an embodiment of the present invention will be described.
According to the image reading apparatus 10, the driving force of the stepping motor 64 is transmitted to the belt 74 wound around the pulley 68 via the driving shaft 66 and the pulley 68. Since a part of the belt 74 is fixed to the scanning body 28, the scanning body 28 is moved by driving the belt 74. At this time, the scanning body 28 is guided by the guide rod 20 and the guide rail 24 and moves in the scanning direction (arrow X direction side in FIG. 1) while keeping the platen glass 16 parallel.

  In reading the image of the document P, first, light is emitted from the light source 38 toward the document P placed on the platen glass 16, the light is reflected by the document P, and the reflected light passes through the slit 34 of the scanning body 28. Enter the inside 40 of the scanning body. Further, the reflected light that has entered the inside of the scanning body 40 is reflected by the first mirror 42, the second mirror 44, the third mirror 46, and the fourth mirror 48 and is collected by the lens 50. The reflected light collected by the lens 50 enters the CCD base 54, and the optical signal is converted into an electrical signal in the CCD base 54. As a result, the image of the original P is read.

After reading the image of the document P, the scanning body 28 is moved toward the start position S in the return direction (arrow Y direction side in FIG. 3).
When the scanning body 28 reaches the start position S, the position detection sensor 60 detects the detection piece 62. When the position detection sensor 60 detects the detection piece 62, the driving of the stepping motor 64 is stopped, and the scanning body 28 stops at the start position S.

  Here, the scanning body 28 does not stop due to a failure of the position detection sensor 60 of the scanning body 28, a control failure, etc., and the scanning body 28 returns beyond the start position S that was scheduled to stop (arrow Y in FIG. 3). If the movement continues to the direction side), the protruding length LR of the rib 78 from the path wall 80 is longer than the protruding length LC of the CCD substrate 54 protruding from the scanning body 28 from the scanning body 28. Therefore, the rib 78 contacts the side wall 52 of the scanning body 28 before the CCD base 54 collides with the housing 12. Thus, further movement of the scanning body 28 in the return direction (arrow Y direction side in FIG. 3) is restricted, and the CCD base 54 can be prevented from colliding with the housing 12.

  In the image reading apparatus 10 of the above-described embodiment, the configuration in which one rib 78 is formed has been described as an example. However, the configuration is not limited thereto, and a plurality of ribs 78 may be provided on the path wall 80. .

  Further, in the image reading apparatus 10 of the above embodiment, the configuration in which the rib 78 is provided on the housing 12 has been described as an example. However, the present invention is not limited to this configuration, and the protrusion is formed on the scanning body 28 instead of the rib 78. A configuration provided with (not shown) may be used. As this protrusion, for example, a part of the scanning body 28 may be protruded in an arbitrary shape toward the return direction (arrow Y direction side in FIG. 2) and integrally formed. Furthermore, a configuration in which both ribs 78 and protrusions (not shown) may be provided.

1 is a side view of an image reading apparatus according to an embodiment of the present invention. 1 is a plan view of an image reading apparatus according to an embodiment of the present invention. 1 is a partial cross-sectional view of an image reading apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image reader 12 Housing | casing 16 Platen glass (original platen)
28 Scanning Body 52 Side Wall 54 CCD Base (Imaging Means)
78 Ribs (Protective members, protrusions)
P manuscript

Claims (2)

A box-shaped housing having an open top surface, a document placing table provided on the top surface of the housing, and a document placed inside the housing and placed on the document placing table by irradiating light. An image reading apparatus including a scanning body for reading an image,
An imaging means for converting an optical signal into an electric signal is provided on one side wall in the moving direction of the scanning body,
A rib is provided on one side wall of the casing opposite to the side wall provided with the imaging means of the scanning body,
The rib has a length longer than a protruding length of the imaging unit from the side wall, and the rib contacts the side wall to prevent the imaging unit from contacting the casing. Image reading device. The scanning body moves along a guide rod penetrating the scanning body,
The rib is provided to extend from the bottom of the housing to the guide rod side,
The image reading apparatus according to claim 1, wherein a height of the rib from the bottom of the housing is higher than a height of the guide rod from the bottom of the housing .

Images