JP6458382B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus.

  In order to expose an image of a document on a photosensitive material, a pair of mirrors that are positioned on the optical path of image light from the document and reflect the image light, a frame having a pair of side walls that are spaced apart from each other, and a pair of And a mirror holding structure for holding a pair of mirrors between a pair of side walls and holding the reflection surfaces of the pair of mirrors facing each other at a predetermined relative angle. The spring is formed in a substantially V shape, and the base end portion of the V shape of the spring is fixed to the frame, and the tip of the spring presses the non-reflecting surface near the longitudinal intermediate portion of each of the pair of mirrors. A held mirror holding structure is known (Patent Document 1).

JP-A-8-76283

  An object of the present invention is to provide an image reading apparatus capable of suppressing mirror vibration without increasing the space of the mirror holding portion.

In order to solve the above problem, an image reading apparatus according to claim 1,
A pair of optical members for guiding the light irradiated and reflected on the irradiated surface to the image sensor with the reflective surfaces facing each other;
A holding member that is spaced apart from each other and holds the pair of optical members while supporting the reflecting surface side at both side ends in the longitudinal direction;
A connecting member connecting the one surface facing each other perpendicular to Oite the reflective surface center of the longitudinal direction of the pair of optical members, including a,
It is characterized by that.

According to a second aspect of the present invention, in the image reading apparatus according to the first aspect,
The connecting member is a plate member having a cross-sectional shape and is connected via the pair of optical members and an adhesive member.
It is characterized by that.

In order to solve the above problem, an image reading apparatus according to claim 3,
A pair of optical members for guiding the light irradiated and reflected on the irradiated surface to the image sensor with the reflective surfaces facing each other;
A holding member that holds the pair of optical members that are spaced apart from each other and that support and hold one of the reflecting surface side and one surface orthogonal to the reflecting surface at both side ends in the longitudinal direction;
Equipped with a pressing member critical damping coefficient for pressing is made of an elastic material is 0.3 to 0.1 one surface facing each other perpendicular to Oite the reflecting surface in the longitudinal direction in central of the pair of optical members ,
It is characterized by that.
Here, the critical damping coefficient is c / (2 when the damping coefficient is c, the mass is M, and the stiffness is K.
* (M * K) 1/2).

The invention according to claim 5 is the image reading apparatus according to claim 3 or 4,
A plate member having a cross-sectional shape is further provided, and the pressing member presses one surface facing each other orthogonal to the reflecting surface via the plate member.
It is characterized by that.

According to the first aspect of the present invention, the vibration of the mirror is suppressed as compared with the case where there is no connecting member that connects the mutually facing surfaces orthogonal to the reflecting surface at the longitudinal center of the pair of optical members. be able to.
According to the second aspect of the present invention, the vibration of the mirror can be suppressed without increasing the space of the mirror holding portion.
According to the third aspect of the present invention, as compared with the case where there is no pressing member that presses one surface facing each other orthogonal to the reflecting surface at the center portion in the longitudinal direction of the pair of optical members, transmission is performed to the pair of optical members. Vibration can be attenuated and the vibration of the mirror can be suppressed.
According to invention of Claim 4 , the fall of the pressing force by a secular change can be suppressed.

1 is a schematic cross-sectional view showing an internal configuration of an image forming apparatus 100 to which an image reading apparatus 1 is applied. 2 is a schematic cross-sectional view showing an internal structure of an image reading unit 20 of the image reading apparatus 1. FIG. 2 is a perspective view illustrating an appearance of a second carriage 24 in the image reading apparatus 1. FIG. 3 is a schematic cross-sectional view showing the arrangement of main members of a second carriage 24 in the image reading apparatus 1. FIG. It is a perspective view showing the appearance of the second carriage 24A in the image reading apparatus 1A. It is a cross-sectional schematic diagram showing the arrangement of main members of the second carriage 24A in the image reading apparatus 1A. FIG. 10 is a schematic cross-sectional view showing the arrangement of main members of a second carriage 24B according to a modified example in the image reading apparatus 1A.

Next, the present invention will be described in more detail with reference to the drawings with reference to the drawings. However, the present invention is not limited to these embodiments.
Also, in the description using the following drawings, it should be noted that the drawings are schematic and the ratio of each dimension and the like are different from the actual ones, and are necessary for the description for easy understanding. Illustrations other than members are omitted as appropriate.

“First Embodiment”
(1) Configuration of Image Reading Apparatus 1 and Image Forming Apparatus 100 FIG. 1 is a schematic cross-sectional view showing an internal configuration of an image forming apparatus 100 to which the image reading apparatus 1 according to the present embodiment is applied.
Hereinafter, the overall configuration and operation of the image forming apparatus 100 and the image reading apparatus 1 will be described with reference to the drawings.

(1, 1) Overall Configuration and Operation of Image Forming Apparatus 100 The image forming apparatus 100 includes an image reading apparatus 1 that reads an image from a document S, and an image forming unit 2 that prints the read image on a sheet P as a recording medium. It is configured with.
The image reading apparatus 1 is supported on the upper side of the main body portion 100A by the support portion 3 so as to form a space in which the printed paper P is discharged between the main body portion 100A housing the image forming portion 2. .

  At the bottom of the image forming unit 2, a paper feeding device 120 on which a large number of recording media P are stacked is provided. The paper P whose position in the width direction is determined by a regulating plate (not shown) is 1 from the top. Each sheet is pulled out side by side by the sheet drawing unit 122 (−X direction) and then conveyed to the nip portion of the registration roller pair 123.

  The photoconductor unit 130 includes a photoconductor drum 131 that is provided in parallel above the paper feeding device 120 (in the Z direction) and serves as an image holding body that is rotationally driven. Yellow (Y), magenta (M), cyan (C), and black (K) toner images are formed on the respective photosensitive drums 131 by the respective developing devices 140.

  Each color toner image formed on the photoconductive drum 131 of each photoconductor unit 130 is sequentially electrostatically transferred (primary transfer) onto the intermediate transfer belt 151 of the transfer device 150 to form a superimposed toner image in which the respective color toners are superimposed. Is done. The superimposed toner image on the intermediate transfer belt 151 is sent out from the registration roller pair 123 and is collectively transferred onto the intermediate transfer belt 151 onto the paper P guided by the conveyance guide.

The paper P onto which the toner images are collectively transferred in the transfer device 150 is conveyed to the fixing device 160 via the conveyance guide in a state where the toner images are not fixed, and is pressed and bonded by the pair of fixing rollers 161 and the pressure roller 162. The toner image is fixed by the action of heating.
The sheet P on which the fixed toner image is formed is discharged to the upper surface of the image forming unit 2.

(1.2) Overall Configuration and Operation of Image Reading Apparatus 1 The image reading apparatus 1 includes an automatic document feeder 10 and an image reading unit 20. The automatic document feeder 10 conveys the document S placed on the document table 11 to the reading position, and discharges the document S after reading to the document discharge unit 12.

  The image reading unit 20 is provided with a platen glass 22 on which an original S is placed on the upper surface of a housing 21, and is provided inside the housing 21 so as to be reciprocally movable in the sub-scanning direction (left-right direction: X direction). The first carriage 23 and the second carriage 24, the imaging lens L1 provided below the folding position in the sub-scanning direction, the image sensor 29 such as a CCD (Charge Coupled Device) line sensor, and the like are arranged. It is configured.

  When the document S is placed on the platen glass 22, the image information is read line by line while sequentially moving the first carriage 23 and the second carriage 24 in the sub-scanning direction. The reflected light is guided to the image sensor 29 to read the entire image of the document S.

(2) Configuration of Image Reading Device 1 FIG. 2 is a schematic cross-sectional view showing the internal structure of the image reading unit 20 of the image reading device 1.

  A platen glass 22 is attached to the upper portion of the casing 21, and the document S is placed on the platen glass 22. A platen cover 22a for pressing the document is attached to the casing 21 so as to be openable and closable.

Below the platen glass 22, a first carriage 23 for holding a first optical system constituted by a light source H and a first mirror M1 is disposed.
The first carriage 23 is guided by a first rail (not shown) together with the light source H and the first mirror M1, and moves by one scanning line in the sub-scanning direction (X direction). 2 is emitted to the optical system.

  In the vicinity of the first carriage 23, a second carriage 24 that holds a second optical system constituted by a second mirror M2 and a third mirror M3 as an example of a pair of optical members is disposed. The second mirror M2 and the third mirror M3 are arranged so as to be perpendicular to each other. The second mirror M2 is disposed in parallel with the first mirror M1.

  The second carriage 24 is interlocked with the first carriage 23 and configured to be reciprocally movable along the sub-scanning direction while being guided by a second rail (not shown). The light reflected in the X direction) is reflected in the vertical direction (Z direction) by the second mirror M2, and the reflected light is reflected again in the horizontal direction (X direction) by the third mirror M3.

  Further, an imaging lens L1 is arranged in the direction of light reflection by the third mirror M3, and an image sensor 29 is arranged at the imaging position of the optical image by the imaging lens L1.

  In the image reading unit 20 configured as described above, the first carriage 23 and the second carriage 24 are driven by a driving mechanism (not shown) so that the optical path length from the reading position of the document image to the image sensor 29 is constant. When driven, the second carriage 24 moves in the same direction at a moving speed V / 2 that is half the moving speed V of the first carriage 23. Here, FIG. 2 shows the first carriage 23 and the second carriage 24 with a two-dot chain line when the first carriage 23 is moved to the folding position in the sub-scanning direction.

(2.2) Configuration of Second Carriage 24 FIG. 3 is a perspective view showing the external appearance of the second carriage 24 in the image reading apparatus 1, and FIG. 4 is a diagram showing the main members of the second carriage 24 in the image reading apparatus 1. It is a cross-sectional schematic diagram which shows arrangement | positioning.
Hereinafter, the configuration of the second carriage 24 will be described with reference to the drawings.

  As shown in FIG. 3, the second carriage 24 includes a second mirror M2, a third mirror M3, a carriage frame 25, a second mirror M2, and a third mirror M3 that face each other at an angle of 90 degrees. The holder part 26, which is an example of a holding member for holding each, and the second mirror M2 and the third mirror M3 are connected at the central part in the longitudinal direction (direction orthogonal to the moving direction) of the second mirror M2 and the third mirror M3. A connecting member 27 is provided.

  The carriage frame 25 is formed by processing a metal plate such as a steel material or aluminum, for example. The carriage frame 25 is a substantially plate-like long member whose longitudinal direction is the main scanning direction (direction orthogonal to the moving direction: Y direction), and has a substantially rectangular opening at the center thereof that is long along the main scanning direction. 25a is formed, and the reflected light reflected by the second mirror M2 passes toward the third mirror M3.

  On both sides of the carriage frame 25, holder portions 26 for supporting the respective end portions of the second mirror M2 and the third mirror M3 and fixing them to the carriage frame 25 are formed.

As shown in FIG. 4, the holder portion 26 is formed with receiving portions 26a for supporting the respective one end portions of the second mirror M2 and the third mirror M3 from the reflecting surfaces M2a and M3a.
The second mirror M2 and the third mirror M3 are fixed to the holder part 26 by being pressed against the receiving part 26a of the holder part 26 via the spring member SR.

The second mirror M2 and the third mirror M3 are orthogonal to the reflecting surfaces M2a and M3a at the center in the longitudinal direction (direction perpendicular to the moving direction: Y direction) with both ends fixed to the holder 26. The opposing side surfaces M2b and M3b are held by the connecting member 27, respectively.
The connection member 27 has a generally U shape in cross-sectional view, and is formed by bending a highly rigid metal plate such as a steel material or aluminum.

The connection member 27 is orthogonal to the reflection surfaces M2a and M3a of the second mirror M2 and the third mirror M3, and is fixed to the side surfaces M2b and M3b facing each other via an adhesive (AD) or a double-sided tape (TP). .
As a result, the adjacent second mirror M2 and third mirror M3 are connected and integrated with each other by a substantially U-shaped connection member 27 in a cross-sectional view at the center in the longitudinal direction, and the second carriage 24 is fast. Even when it moves, the bending and vibration of the second mirror M2 and the third mirror M3 can be suppressed.
Further, since the connection member 27 fixes the side surfaces M2b and M3b orthogonal to the reflection surfaces M2a and M3a of the second mirror M2 and the third mirror M3, the reflection surfaces M2a and M3a do not bend and read. A change in magnification of the image is also suppressed.

  As shown in FIG. 4, the connecting member 27 is orthogonal to the reflecting surfaces M2a and M3a of the second mirror M2 and the third mirror M3, and faces the side surfaces M2b and M3b, respectively, and an adhesive (AD) or a double-sided tape (TP). Therefore, in the state where the second carriage 24 is positioned at the initial position (home position), there is little protrusion toward the inner surface 21a side of the housing 21, and the space inside the image reading apparatus 1 is increased. Can be suppressed.

“Second Embodiment”
FIG. 5 is a perspective view showing the appearance of the second carriage 24A in the image reading apparatus 1A, FIG. 6 is a schematic sectional view showing the arrangement of main members of the second carriage 24A in the image reading apparatus 1A, and FIG. It is a cross-sectional schematic diagram which shows arrangement | positioning of the main members of the 2nd carriage 24B which concerns on the modification in apparatus 1A.

  As shown in FIG. 5, the second carriage 24A in the image reading apparatus 1A includes a second mirror M2, a third mirror M3, a carriage frame 25 as a frame, and a second frame M2, which are opposed to each other at an angle of 90 degrees. A holder portion 26 as a holding member for holding the second mirror M2 and the third mirror M3, and a second central portion in the longitudinal direction (direction perpendicular to the moving direction: Y direction) of the second mirror M2 and the third mirror M3. An elastic member 27A as an example of a pressing member that presses the mirror M2 and the third mirror M3 is provided.

  In the present embodiment, the second mirror M2 and the third mirror M3 are supported by an elastic member 27A at the center in the longitudinal direction (direction perpendicular to the moving direction: Y direction). It differs from the image reading apparatus 1 according to the embodiment. Accordingly, the same components as those in the image reading apparatus 1 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  On both sides of the carriage frame 25, holder portions 26 for supporting the respective end portions of the second mirror M2 and the third mirror M3 and fixing them to the carriage frame 25 are formed.

As shown in FIG. 6, the holder portion 26 includes a receiving portion 26a that supports both end portions of the second mirror M2 and the third mirror M3 from the reflecting surfaces M2a and M3a, and a side surface M2b that intersects the reflecting surfaces M2a and M3a. , A receiving portion 26b that supports one surface of M3b is formed.
Moreover, each holder part 26 is integrally connected by the connection part 26c in the center part.

  The second mirror M2 and the third mirror M3 are orthogonal to the reflecting surfaces M2a and M3a at the center in the longitudinal direction (direction perpendicular to the moving direction: Y direction) with each end held by the holder 26. The opposing side surfaces M2b and M3b are held with the elastic member 27A sandwiched therebetween. As a result, one surface of the side surfaces M2b and M3b intersecting the reflecting surfaces M2a and M3a is pressed against the receiving portion 26a of the holder portion 26 via the spring member SR in a state where the one surface is pressed against the receiving portion 26b of the holder portion 26. Is fixed.

The elastic member 27A is not particularly limited as long as it has a vibration damping action that reduces vibration transmitted from the carriage frame 25 through the holder portion 26, but the damping ratio A is about 0.1 to 0.3. Of these, natural rubber, silicon rubber, and foamable polyurethane are suitable. Here, the attenuation ratio A is expressed by A = c / (2 * (M * K) ^1/2 ) (c is an attenuation coefficient, M is mass, and K is rigidity).

In a state where both ends are held by the holder portion 26, the central portion in the longitudinal direction (direction perpendicular to the moving direction: Y direction) is perpendicular to the reflecting surfaces M2a and M3a, and is sandwiched between the opposite side surfaces M2b and M3b. The second mirror M2 and the third mirror M3 can act as a constraining layer for the elastic member 27A on the elastic member 27A that is the vibration damping material, so that vibration transmitted from the holder portion 26 can be attenuated.
Therefore, even when the second carriage 24A moves at a high speed, the bending and vibration of the second mirror M2 and the third mirror M3 can be suppressed.
Further, since the elastic member 27A presses the side surfaces M2b and M3b orthogonal to the reflection surfaces M2a and M3a of the second mirror M2 and the third mirror M3, the reflection surfaces M2a and M3a do not bend and read. A change in magnification of the image is also suppressed.

(Modification)
As shown in FIG. 7, the elastic member 27 </ b> B has a generally U-shaped cross-sectional view, and a plate spring member 28 as an example of a plate member formed by bending a metal plate such as steel or aluminum. May be arranged.
Since the opposing side surfaces M2b and M3b of the second mirror M2 and the third mirror M3 are held with the elastic member 27B sandwiched via the leaf spring member 28, the pressing force of the elastic member 27B due to secular change is reduced. The decrease can be suppressed.

The embodiments of the present invention have been described with specific examples. However, the technical scope of the present invention is not limited to the above-described embodiments, and various modifications are made without departing from the spirit of the present invention. It is possible.
For example, the image reading apparatus in which the opposite side surfaces of a pair of mirrors held by a carriage provided so as to be capable of reciprocating movement are held by a connecting member and the image reading apparatus pressed by a pressing member has been described as an example. A connecting member or a pressing member can be attached to a pair of mirrors provided in an exposure apparatus that forms a latent image on the photosensitive drum, thereby suppressing vibration of the mirrors.

DESCRIPTION OF SYMBOLS 1, 1A ... Image reading apparatus 10 ... Automatic document feeder 20 ... Image reading part 21 ... Case 22 ... Platen glass 23 ... 1st carriage 24, 24A ... Second carriage 25 ... carriage frame 26 ... holder portion 27 ... connecting member 27A, 27B ... elastic member 28 ... plate spring member M1 ... first mirror M2 ... second Mirror M3 ... Third mirror L1 ... Lens H ... Light source SR ... Spring member

Claims (4)

A pair of optical members for guiding the light irradiated and reflected on the irradiated surface to the image sensor with the reflective surfaces facing each other;
A holding member that is spaced apart from each other and holds the pair of optical members while supporting the reflecting surface side at both side ends in the longitudinal direction;
A connecting member connecting the one surface facing each other perpendicular to Oite the reflective surface center of the longitudinal direction of the pair of optical members, including a,
An image reading apparatus. The connecting member is a plate member having a cross-sectional shape and is connected via the pair of optical members and an adhesive member.
The image reading apparatus according to claim 1. A pair of optical members for guiding the light irradiated and reflected on the irradiated surface to the image sensor with the reflective surfaces facing each other;
A holding member that holds the pair of optical members that are spaced apart from each other and that support and hold one of the reflecting surface side and one surface orthogonal to the reflecting surface at both side ends in the longitudinal direction;
Equipped with a pressing member critical damping coefficient for pressing is made of an elastic material is 0.3 to 0.1 one surface facing each other perpendicular to Oite the reflecting surface in the longitudinal direction in central of the pair of optical members ,
An image reading apparatus.
Here, the critical damping coefficient is c / (2 when the damping coefficient is c, the mass is M, and the stiffness is K.
* (M * K) 1/2). A plate member having a cross-sectional shape is further provided, and the pressing member presses one surface facing each other orthogonal to the reflecting surface via the plate member.
The image reading apparatus according to claim 3.

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