JPH08114863A - Optical device - Google Patents

Abstract

PURPOSE: To provide an optical device capable of obtaining high quality images by reducing vibration in a reflective mirror. CONSTITUTION: In an optical device having a plurality of reflective mirrors 3, 5, 6, 8, 9 and 10 and an image forming lens 7 for projecting an original image onto a photoreceptor 61, at least one, for instance 10, among the reflective mirrors 3, 5, 6, 8, 9 and 10, is rotated around an axis parallel to the reflective mirror 10 and perpendicular to a light axis 7a passing through an intersection between the reflective mirror 10 and the image forming lens 7, an adjusting means is provided for adjusting the posture of the reflective mirror 10 and a tightening/fitting means elastically deformed in the radial direction of an axis having an inner diameter smaller than the outer diameter of a shaft for elastically supporting the shaft is provided in a supporting part for supporting at least one end of the rotated reflective mirror 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device in an image forming apparatus such as a copying machine or a printer, and more particularly to a supporting portion of a reflecting mirror.

[0002]

2. Description of the Related Art An optical device such as a copying machine is provided with a plurality of reflection mirrors, and an original image is reflected a plurality of times by a plurality of reflection mirrors and projected onto a photoconductor. The reflection mirror is
In order to maintain the performance of the optical device, its posture is maintained within a specified range. Alternatively, the attitude is adjusted by the adjusting means for adjusting the attitude of the reflecting mirror.

Japanese Unexamined Patent Publication No. 60-53946 and Japanese Utility Model Laid-Open No. 3-35536 disclose optical devices in which the attitude of a reflecting mirror can be adjusted. Japanese Patent Laid-Open No. 60-53946
In the reflection mirror whose posture can be adjusted, which is described in Japanese Patent Laid-Open Publication No. 7-52, both ends of a mirror 70 are held by brackets 72 fixed to a bracket holder 71.
At both ends of 1, pass through the intersection of the mirror 70 and the optical axis, and the mirror 7
A rotation center pin 73 is provided which extends on a straight line 74 orthogonal to the optical axis in the 0 plane, and the attitude of the mirror 70 is adjusted by rotating the rotation center pin 73.

A reflection-adjustable reflection mirror disclosed in Japanese Utility Model Laid-Open No. 3-35536 has a plurality of mirrors for forming an exposure optical path for forming a document image on a photoconductor 80.
The pair of mirrors 81 and 82 are supported by a rotation center axis rod 83 which is rotatable about an axis parallel to the mirror surface and perpendicular to the optical path. The rotation center axis rod 83 is rotated. The attitude of the mirrors 81 and 82 is adjusted.

[0005]

However, when the rotating shaft of the reflecting mirror is rotatably supported, the outer diameter of the rotating shaft and the inner diameter of the hole in which the rotating shaft is supported are set. There was a gap between them. This gap is created because the rotation shaft and the hole are loosely fitted to each other with a fitting tolerance. Therefore, the reflection mirror arranged near the photoconductor
It was easily affected by vibrations caused by driving the photoconductor driving device and the developing device. Due to this vibration, the reflection mirror vibrates and the posture of the reflection mirror is changed, so that there is a problem that the quality of the image is deteriorated.

Particularly in recent copying machines and the like, there is a demand for speeding up, widening of the zooming range, and cost reduction, so that the size of the reflecting mirror becomes large, especially the length in the longitudinal direction of the mirror becomes long. The tendency is that the reflecting mirror is susceptible to vibration. Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an optical device that reduces vibration of a reflection mirror and obtains a high-quality image.

[0007]

According to a first aspect of the present invention, in an optical device having a plurality of reflecting mirrors and an image forming lens for projecting a document image on a photosensitive member, at least the plurality of reflecting mirrors are provided. One reflecting mirror is rotated about an axis that is parallel to the reflecting mirror and orthogonal to the optical axis, passing through the intersection of the reflecting mirror and the optical axis of the imaging lens, and the posture of the reflecting mirror is changed. An optical device having an adjusting means for adjusting, wherein a supporting portion that supports at least one end of a rotating reflection mirror is elastically deformable in the radial direction of the shaft and has an inner diameter smaller than the outer diameter of the shaft. It is configured to include a fastening means that elastically supports the shaft.

According to a second aspect of the present invention, the fastening means is made of a thermoplastic resin and has a plurality of slits formed in the axial direction.

According to a third aspect of the invention, the fastening means is an elastic body disposed inside the support portion.

According to a fourth aspect of the invention, the elastic body is composed of at least one rubber O-ring.

According to a fifth aspect of the invention, there is provided a means for regulating the elastic deformation amount of the elastic body.

[0012]

According to the first aspect of the present invention, the supporting portion supporting at least one end of the rotating reflecting mirror can be elastically deformed in the radial direction of the axis of the reflecting mirror, and has a diameter larger than that of the outer diameter of the shaft. Since the fastening means having the small inner diameter is provided, when the shaft is inserted into the fastening means, the fastening means elastically deforms to tightly fit the shaft.

According to the second aspect of the present invention, since the interference fitting means is made of thermoplastic resin and the plurality of slits are formed in the axial direction of the reflecting mirror, when the shaft is inserted into the interference fitting means, The fitting means is radially deformed to tightly fit the shaft.

According to the third aspect of the present invention, since the elastic body is arranged inside the support portion, when the shaft of the reflecting mirror is supported by the elastic body, the elastic body is deformed and the shaft is tightly fitted.

According to the fourth aspect of the present invention, since the elastic body is composed of at least one rubber O-ring, when the axis of the reflecting mirror is supported by the O-ring, the O-ring is expanded and deformed to move the axis. Fit tightly.

According to the fifth aspect of the present invention, since the elastic body has the means for regulating the elastic deformation amount of the elastic body, the elastic force of the elastic body which is tightly fitted on the shaft of the reflection mirror is changed.

[0017]

1 is a schematic view of an optical device of a copying machine.
In the figure, reference numeral 40 indicates an optical device. A document feeding unit 50 that feeds a document is provided above the optical device 40, and an image forming unit 60 that forms an image is provided below the optical device 40. The optical device 40 is composed of a plurality of reflecting mirrors, an imaging lens, and the like, which will be described later. The image forming section 60 is configured such that a photoconductor 61 is arranged substantially in the center thereof, and a charging device, a developing device, a transfer device, a cleaning device, and the like are arranged around the photoconductor 61. The document feeding section 50 includes a feeding device that feeds a document, a contact glass 51 on which the document is placed, and the like.

The contact glass 51 is provided between the optical device 40 and the document feeding section 50. Below the contact glass 51, the document placed on the contact glass 51 is exposed. First scanner 1 for scanning
, Are arranged so as to be movable in the direction along the document (the direction of arrow A in the figure). The first scanner 1 includes an exposure lamp 2 and a first reflecting mirror 3 provided near the exposure lamp 2. Between the optical path from the first reflection mirror 3 to the photoconductor 61, the second scanner 4, the imaging lens 7, the fourth reflection mirror 8, the fifth reflection mirror 9, and the sixth reflection mirror are arranged in this order from the first reflection mirror 3. Mirrors 10 are provided respectively. In the second scanner 4, a second reflection mirror 5 that receives light from the first reflection mirror 3 and a third reflection mirror 6 that receives and reflects light from the second reflection mirror 5 are arranged at right angles. , Is arranged so as to be movable in association with the movement of the first scanner 1. The imaging lens 7 collects the light from the third reflection mirror 6 and projects it onto the fourth reflection mirror 8. A fourth reflecting mirror 8 for receiving the light from the imaging lens 7 and the fourth reflecting mirror 8.
The fifth reflection mirror 9 which receives and reflects the light from the reflection mirror 8 is arranged at a right angle. 6th reflection mirror 10
Are arranged so as to project the light from the fifth reflection mirror 9 onto the photoconductor 61.

The first reflecting mirror 3 to the sixth reflecting mirror 10 and the imaging lens 7 each have adjusting means for adjusting and holding their postures within a predetermined range.
In particular, as shown in FIG. 2, the sixth reflecting mirror 10 passes through the intersection 12 of the sixth reflecting mirror 10 and the optical axis 7a so that the optical axis 7a of the imaging lens 7 faces the center of the photoconductor 61, Sixth
It is configured to be rotatable about a central axis 13 that is parallel to the reflection mirror 10 and is orthogonal to the optical axis 7a.

The operation of the optical device 40 will be described. The document feeding unit 50 feeds the document onto the upper surface of the contact glass 51. The original is scanned by the first scanner 1 via the contact glass 51. This scanning light is reflected by the second reflection mirror 5 and the third reflection mirror 6 and projected onto the imaging lens 7. The scanning light from the imaging lens 7 is reflected by the fourth reflecting mirror 8 to the fifth reflecting mirror 9. The scanning light reflected by the fifth reflection mirror 9 is reflected by the sixth reflection mirror 10 adjusted so that the optical axis 7 a is directed to the center of the photoconductor 61 and projected on the photoconductor 61. Therefore, when the first scanner 1 scans the document, the document image is projected on the photoconductor 61.

Next, some embodiments of the present invention will be described with reference to the drawings. First, a first embodiment will be described. As shown in FIG. 3, the sixth reflecting mirror 10 is held by a mirror unit 14 described later,
Adjusting means 17 for adjusting the posture of the
Is detachably supported by a shaft support member 23 that rotatably supports. Further, the mirror unit 14 is provided with fixing means (not shown) for fixing the mirror unit 14 to the adjusting means 17.

The mirror unit 14 is formed in a substantially U shape, and holds the sixth reflecting mirror 10 so that both ends in the longitudinal direction of the mirror 10 are sandwiched from both sides.
At one end of the mirror unit 14, there is provided a positioning portion 14a having two positioning holes 21a, 21a for determining the position where the mirror unit 14 is attached to the adjusting means 17. A reference pin 22 whose center is concentric with the central axis 13 is provided at the other end.

The adjusting means 17 is a side plate 15 of the optical device 40.
A positioning plate 19 which is disposed on the outer side of the positioning plate 19 and is rotatable around the central shaft 13; and a cam 2 which rotates the positioning plate 19.
It consists of 0 and. The positioning plate 19 has two positioning pins 21 and 21 that engage with the positioning holes 21a and 21a.
1 is provided. A mounting hole 15 for mounting the mirror unit 14 is provided near the adjusting means 17 of the side plate 15.
The shaft support member 23 provided with a is provided inside the side plate 16 of the optical device 40, and is made of plastic, specifically,
A guide portion 23a made of a thermoplastic resin such as ABS, PC, PPE, etc., which facilitates insertion of the reference pin 22.
And a support portion 23b provided on the opposite side to support the reference pin 22.

As shown in FIG. 4, the support portion 23b has a fitting portion 24 having an inner diameter slightly larger than the outer diameter of the reference pin 22 for facilitating the attachment and detachment of the reference pin 22, and the reference pin 2.
2 and an interference fitting portion 25 having an inner diameter smaller than the outer diameter. In FIG. 5, the interference fitting portion 25 is provided with a cross-shaped slit 26 in the axial direction of the reference pin 22 so that the reference pin 2
Four elastic pieces 25a for holding 2 are formed.

The attachment of the mirror unit 14 and the attitude adjustment will be described. In FIG. 3, the positioning hole 21
The mirror unit 14 is tilted so that a and 21a engage with the positioning pins 21 and 21, the mirror unit 14 is inserted into the mounting hole 15a, and the reference pin 22 is fixed to the support portion 2.
Insert into 3b. At this time, the tip of the reference pin 22 is guided by the guide portion 23a and inserted into the support portion 23b. In FIG. 6, when the reference pin 22 is loosely fitted into the fitting portion 24 and is inserted into the tightening portion 25, the elastic piece 25 a is elastically deformed radially in the tightening portion 25. The reference pin 22 is tightened and supported by the elastically deformed elastic piece 25a. The positioning holes 21a and 21a have positioning pins 21 and 21, respectively.
After being engaged with 1, the mirror unit 14 is fixed to the adjusting means 17 by a fixing means (not shown).

By rotating the cam 20 in the direction of the arrow B, the positioning plate 19 is rotated about the central axis 13 so that the optical axis 7a of the imaging lens 7 faces the center of the photosensitive member 61. The attitude of the mirror unit 14 is adjusted. Therefore, even if vibration occurs due to the driving of the photoconductor 61 or the like after the attitude adjustment of the mirror unit 14, the reference pin 22 is tightly fitted by the elastic piece 25a, so that the influence of vibration is prevented. Further, by changing the length or width of the slit 26 or the inner diameter of the tightening portion 25, the reference pin 2
It is also possible to change the strength of the holding force of 2 and to easily attach and detach the reference pin 22.

Next, FIGS. 7 and 8 show a second embodiment of the present invention. Differences from the first embodiment will be described, and the same members as those shown in FIG. 4 will be denoted by the same reference numerals as those used in FIG. 4, and the description thereof will be omitted. In FIG.
A hole having the same diameter as the fitting portion 24 is formed in the fitting portion 30.
And a rubber O-ring 31 having an inner diameter smaller than the outer diameter of the reference pin 22 is provided. A groove 30 a that accommodates the O-ring 31 is provided on the inner peripheral surface of the interference fit portion 30.

When the reference pin 22 is inserted into the interference fitting portion 30 thus constructed, as shown in FIG.
1 is elastically deformed so as to be spread. By this elastic deformation, the reference pin 22 is tightly fitted and held.

Furthermore, FIG. 9 shows a third embodiment of the present invention. In the figure, the same members as those shown in FIG. 7 are denoted by the same reference numerals as those used in FIG. 7, and the description thereof will be omitted and different points will be described. In FIG. 9, an O-ring storage chamber 33 having a diameter substantially the same as the outer diameter of the O-ring 31 is provided on the inner peripheral surface of the fitting portion 32. A cap nut 34 that widens or narrows the accommodation space of the O-ring accommodation chamber 33 and a fixing nut 35 that fixes the cap nut 34 are screwed onto the outer periphery of the fastening portion 32.

According to the tightening portion 32 thus constructed, when the fixing nut 35 is loosened and the cap nut 34 is tightened,
The storage space of the O-ring storage chamber 33 is narrowed, and the cap nut 3
When 4 is loosened, the storage space of the O-ring storage chamber 33 expands. If the reference pin 22 is inserted into the tightening portion 32 when the accommodation space of the O-ring accommodation chamber 33 is narrow, the amount of elastic deformation of the O-ring 31 is restricted, so that the holding force of the reference pin 22 is increased. When the accommodation space of the O-ring accommodation chamber 33 is large, the elastic deformation amount of the O-ring 31 is not regulated. Therefore, when the reference pin 22 is inserted into the fitting portion 32, the accommodation space of the O-ring accommodation chamber 33 is narrow. The holding force of the reference pin 22 is weaker than in the case.

Therefore, by rotating the cap nut 34, the accommodation space of the O-ring accommodation chamber 33 is widened and the amount of elastic deformation of the O-ring 31 is adjusted, and the holding force of the reference pin 22 is adjusted. When the optimum holding force of the reference pin 22 is determined in this way, the fixing nut 35 is tightened to tighten the cap nut 3
4 is fixed. Therefore, the holding force for tightly fitting the reference pin 22 becomes variable, and a versatile tightening means can be provided.

The O-ring 31 is stipulated in JIS in terms of size, material, etc., and is generally low in cost, so that it is easily available. A plurality of O-rings 31 may be used to increase the holding force of the reference pin 22. Although the shaft support member 23 is used at one end of the mirror unit 14 in the above-described embodiment, the shaft support member 23 may be used at both ends of the mirror unit 14.

[0033]

According to the first aspect of the present invention, since the axis of the reflecting mirror is elastically fitted and supported, the influence of vibration due to the driving of the photoconductor driving device and the developing device can be minimized. Therefore, the quality of the image can be improved.

According to the second aspect of the present invention, since the interference fitting means is formed of the thermoplastic resin, the dimensional error of the interference fitting means is reduced. Also, the cost can be reduced.

According to the third aspect of the present invention, since the shaft of the reflection mirror is elastically fitted by disposing the elastic body inside the support portion, the influence of vibration can be minimized. You can

According to the invention of claim 4, since the rubber O-ring is used for the elastic body, the shaft of the reflection mirror can be tightly fitted at a low cost.

According to the fifth aspect of the present invention, the elastic force of the elastic body that tightly fits the shaft of the reflection mirror is changed by providing the means for regulating the elastic deformation amount of the elastic body. The error can be absorbed.

[Brief description of drawings]

FIG. 1 is a schematic front view of a copying machine including an optical device of the present invention.

FIG. 2 is a perspective view of a reflection mirror illustrating a central axis for adjusting the attitude of the reflection mirror.

FIG. 3 is a perspective view of a reflection mirror showing a first embodiment of the present invention.

FIG. 4 is a side view of a partial cross section of the interference fitting means.

FIG. 5 is a perspective view of a shaft support portion.

FIG. 6 is a partial cross-sectional side view showing the interference fitting means in which the reference pin is inserted in FIG.

FIG. 7 is a side view of a partial cross section of the interference fitting means showing the second embodiment of the present invention.

FIG. 8 is a side view of a partial cross section showing the fastening means in which the reference pin is inserted in FIG.

FIG. 9 is a side view of a partial cross section of an interference fitting means showing a third embodiment of the present invention.

FIG. 10 is a perspective view of a reflection mirror support portion of a conventional optical device.

FIG. 11 is a schematic view of a reflective mirror of a conventional optical device.

[Explanation of symbols]

 3 1st reflection mirror 5 2nd reflection mirror 6 3rd reflection mirror 7 Imaging lens 8 4th reflection mirror 9 5th reflection mirror 10 6th reflection mirror 17 Adjustment means 22 Reference pin 23 Shaft support member 24 Fitting part 25, 30, 32 Tight-fitting portion 31 O-ring 34 Cap nut 35 Fixed nut 61 Photoreceptor

Claims (5)

[Claims] 1. An optical device having a plurality of reflection mirrors and an image forming lens for projecting an original image on a photoconductor, wherein at least one reflection mirror among the plurality of reflection mirrors is the reflection mirror. An optical device having an adjusting unit that adjusts the attitude of the reflecting mirror by rotating it around an axis that is parallel to the reflecting mirror and is orthogonal to the optical axis, passing through the intersection with the optical axis of the imaging lens. And a support portion that supports at least one end portion of the rotating reflection mirror is elastically deformable in the radial direction of the shaft,
An optical device having an inner diameter smaller than the outer diameter of the shaft, and having a fastening means for elastically supporting the shaft. 2. The optical device according to claim 1, wherein the fastening means is made of a thermoplastic resin and has a plurality of slits formed in the axial direction. 3. The optical device according to claim 1, wherein the interference fitting means is an elastic body disposed inside the supporting portion. 4. The optical device according to claim 3, wherein the elastic body comprises at least one rubber O-ring. 5. The optical device according to claim 3, further comprising means for restricting an elastic deformation amount of the elastic body.