JPH10282399A - Light reflecting mirror - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict the oscillation and poor resolution of an image due to the oscillation of a mirror and prevent trouble such as image distortion and magnification error due to the deterioration of the flatness of the mirror by adhering a reinforcing member on the side face along the longitudinal direction of the mirror. SOLUTION: A reinforcing member 34 is adhered to the side face along the longitudinal direction of a mirror 21 with a double coated tape 24. The reinforcing members 34 can be adhered to both side faces, respectively. Otherwise, the reinforcing member 34 can be adhered to the mirror 21 with adhesive instead of the double coated tape 24. In this way, as the reinforcing member 34 is adhered to the single side face or both side faces along the longitudinal direction of the light reflecting mirror, the rigidity of the mirror is improved, the specific oscillation frequency of the mirror is increased and the oscillation of the mirror with specific oscillation is prevented. Compared with a case that reinforcing gent is conventionally adhered to the back of the mirror, the flatness of the reflecting surface of the mirror is more precisely maintained, thus to prevent trouble such as image distortion and magnification error due to the deterioration of the flatness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical folding mirror which can be applied to an image forming apparatus such as a copying machine, a printer, a facsimile and the like.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, a facsimile, or the like, reflected light from a document is read and subjected to optical processing to be converted into an electric signal or an image signal. The electric signal having the image information is optically processed using a laser diode (LD) or the like to form an image. In this case, the reflected light from the document and the laser diode (LD) beam are turned back by one or a plurality of light turning mirrors, then condensed by a lens, and then charged by a CCD (charge coupled device) or photoconductor. An image is formed on the drum.

[0003] The accuracy of the light folding mirror also affects the quality of the image formed. That is, when the optical turning mirror vibrates due to the vibration of the motor, the moving body, and other vibration sources, the quality of the formed image deteriorates. Therefore,
As described in Japanese Utility Model Application Laid-Open No. 1-142913, in a laser beam optical system that reflects a laser beam by a mirror and irradiates the photoconductor,
2. Description of the Related Art An anti-vibration structure of a laser beam optical system mirror in which a rigid plate is bonded via an elastic bonding portion is known.

In the conventional example, as shown in FIG. 7, a reinforcing member 23 such as a metal plate or a glass plate is adhered to a surface opposite to a reflection surface of the mirror 21 with a double-sided tape 24 or the like. The object of the present invention is to increase the rigidity of the mirror 21, increase the resonance frequency, and shift the vibration resonance point to eliminate the vibration of the mirror 21.

However, in the above-mentioned conventional example, there is a problem in that the reinforcing member 23 is bonded on the side opposite to the side used as the reflecting surface of the mirror 21. Usually, the float glass plate used as the material of the mirror has better flatness on one surface than the other surface, and the surface with the better flatness is used as the reflecting surface. When the reinforcing member 23 is bonded to the side, even if the flatness is relatively good, the glass delicately bends along the curved surface on the back side by this bonding, and as a result, the flatness on the reflection surface side of the mirror is reduced. It becomes worse, resulting in problems such as distortion of the formed image and a change in magnification. Also,
Due to the unevenness of the thickness of the adhesive member such as the double-sided tape 24 and the variation of the adhesive force depending on the location, an uneven force is applied between the reinforcing member 23 and the mirror 21 in the thickness direction, and the flatness of the mirror reflecting surface is slightly delicate. It can go crazy.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and suppresses image fluctuation and poor resolution due to mirror vibration, image distortion and magnification error due to deterioration of mirror flatness. It is an object of the present invention to provide an optical turning mirror capable of preventing the problem described above.

[0007]

According to a first aspect of the present invention, there is provided a light reflecting mirror of an image forming apparatus used in a copying machine or the like, wherein a side surface along a longitudinal direction of the light reflecting mirror is provided. Characterized in that a reinforcing member is bonded to one or both sides thereof.

According to a second aspect of the present invention, in the first aspect of the invention, the reinforcing member has a thermal expansion coefficient substantially equal to that of the mirror substrate.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the reinforcing member and the optical turning mirror are fixed by a double-sided tape having elasticity.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the reinforcing member and the light turning mirror are bonded at a plurality of positions in a longitudinal direction.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an optical turning mirror according to an embodiment of the present invention. In the scanner device 1 of the analog copying machine shown in FIG.
A first traveling body 100 and a second traveling body 101 are arranged below the contact glass 11 on which the document 16 is placed. First
The traveling body 100 includes an illumination lamp 14 and a first mirror 12-1, and the illumination lamp 14 and the first mirror 12-1 are integrally movable. The first mirror 12-1 reflects light reflected from the document in the horizontal direction. Also, the second traveling body 1
Reference numeral 01 denotes a second mirror 12-2 and a third mirror 12-3, and the second and third mirrors 12-2 and 12-3 are integrally movable. Second and third mirrors 12-2 and 12
-3 is slanted so that the reflection surfaces are at right angles to each other,
The reflected light from the mirror 12-1 is turned back in the horizontal direction. Thereafter, the reflected light is focused by the lens 13 and reflected by the fourth mirror 12-4 to form a latent image on the photosensitive drum 15, and this latent image is visualized by a developing unit (not shown) to form an image. .

The first traveling body 100 and the second traveling body 101 are both driven by a traveling body motor (not shown) as a drive source and are movable in the direction of the arrow. At this time, in order to keep the optical distance from the original being exposed to the photosensitive drum 15 constant,
The first traveling body 100 moves at twice the speed V with respect to the second traveling body 101. In FIG. 4, the portion indicated by a dashed line indicates the positions of the mirrors 12-1, 12-2, and 12-3 after scanning the document 16. Illumination lamp 14, first to fourth mirrors 12-1,
12-2, 12-3, 12-4 and the lens 13 operate in the same manner as in the example shown in FIG.

Further, in the scanner device 2 of the digital copying machine as shown in FIG. 5, light emitted from the illumination lamp 14 is reflected by the original 16 and the reflected light is reflected by the first mirror 12.
-1, second mirror 12-2, third mirror 12-3, fourth
The light is reflected in the order of the mirrors 12-4, passes through the lens 13, forms an image on the photoelectric conversion surface of the CCD 17 as a photoelectric conversion element, and takes out an image signal of the document as an electric signal.

The image signal converted into an electric signal in the scanner device 2 is converted into a latent image by the optical writing unit 3 shown in FIG. The optical writing unit 3 includes a laser diode (not shown) as an optical element, a light emission drive control unit (not shown), a polygon scanner 31 and a rotation motor (not shown),
f / θ lenses 32-1 and 32-2, folding mirror 33
-1 and the like. In the optical writing unit 3,
The image data (which may be color image data) from the scanner 2 is converted into an optical signal, optical writing corresponding to the original image is performed, and an electrostatic latent image is formed on the photosensitive drum 15. Light emitted from a laser light source (not shown) is reflected by a polygon scanner 31 rotating at high speed, guided to lens systems 32-1 and 32-2 having an fθ function, and reflected obliquely downward by a return mirror 33-1. Lens 32-3
And is reflected by the optical turning mirror 33-2 to form an image as a light beam reciprocating on the photosensitive drum 15. The laser light is turned on by a computer or the like in accordance with the image signal intensity level of the read original.
/ OFF control, and an image is formed on the photosensitive drum 15.

An optical turning mirror used in the above-described scanner devices 1 and 2 and the optical writing unit 3 usually has a configuration as shown in FIG. The mirror 21 is simply fixed by the fixtures 25 provided at both ends in the mirror longitudinal direction, and vibrations and the like generated in the movable parts of the scanner devices 1 and 2 and the optical writing unit 3 are easily transmitted. There has been a problem that the mirror 21 causes lateral natural vibration, and as a result, a formed image has an adverse effect such as shaking and defocus.

In the embodiment of the present invention shown in FIG. 1, a reinforcing member 34 is adhered to a side surface along the longitudinal direction of the mirror 21 with a double-sided tape 24. Although the example of FIG. 1 shows an example in which the reinforcing member 34 is bonded to only one of the side surfaces of the mirror 21, the reinforcing member 34 may be bonded to both of the side surfaces. Further, the reinforcing member 34 may be bonded to the mirror 21 with an adhesive instead of the double-sided tape 24. As described above, since the reinforcing member 34 is bonded to one or both sides of the side surface along the longitudinal direction of the optical turning mirror 21, the mirror rigidity can be increased, the natural vibration frequency of the mirror can be increased, and the vibration due to the natural vibration of the mirror can be achieved. Can be prevented from occurring. In addition, compared to the case where a reinforcing material is adhered to the back surface of the mirror as in the conventional case, the flatness of the reflecting surface of the mirror can be maintained quite precisely, while suppressing image shaking and poor resolution due to mirror vibration. In addition, problems such as image distortion and magnification error due to deterioration of flatness can be prevented.

The mirror 21 and the reinforcing member 34 may be made of glass, or the mirror 21 and the reinforcing member 34 may be made of glass.
The materials may be different as long as they have the same degree of expansion. In this way, by making the expansion coefficient of the material of the mirror 21 and that of the reinforcing member 34 approximately the same, even if the temperature rises due to the use of the image forming apparatus, the mirror 21 is displaced by the difference in the thermal expansion coefficient due to the difference in the thermal expansion coefficient. Deformation and peeling of the adhesive do not occur.

In FIG. 1, the mirror 21 and the reinforcing member 34
Is bonded with a double-sided tape 24 having elasticity. If the double-sided tape 24 for bonding the folding mirror 21 and the reinforcing member has no elasticity, the surrounding temperature changes,
Due to the difference in the coefficient of thermal expansion between the mirror 21 and the double-sided tape 24 or between the reinforcing member 34 and the double-sided tape 24, the mirror 21 and the reinforcing member 34 are displaced, and the mirror 21 is deformed and the adhesive is peeled off. However, by using the double-sided tape 24 having elasticity as in the present invention, the problem of the bonding portion between the mirror 21 and the reinforcing member 34 due to the temperature change can be solved.

In the example shown in FIG. 2, the mirror 21 and one reinforcing member 34 are bonded at three places in the longitudinal direction of the mirror. As described above, according to the mirror 21 bonded to the reinforcing member 34 at a plurality of positions in the longitudinal direction, the double-sided tape 24 is applied to the entire surface of the reinforcing member 34 as in the example shown in FIG. The bonding area can be reduced as compared with the case of bonding, and furthermore, the bonding such as the displacement of the bonding portion or the peeling of the bonding due to the difference in the coefficient of thermal expansion between the mirror 21 and the double-sided tape 24 or between the reinforcing member 34 and the double-sided tape 24. It is possible to make it more difficult for the unit to malfunction. In addition,
The bonding location can be appropriately changed depending on the size of the mirror and the like.

The optical turning mirror according to the present invention is applicable not only to a fixed mirror but also to a movable mirror. For example, in the examples of FIGS. 1 and 2, the first to fourth mirrors 12-
1, 12-2, 12-3, 12-4, and the folding mirrors 33-1 and 33-2 in FIG.

[0021]

According to the first aspect of the present invention, in an image forming apparatus such as a copying machine, one side or both sides of a side surface along a longitudinal direction of a light return mirror substrate for returning light reflected from a document is reinforced. Since the members are bonded, the rigidity of the mirror can be increased, the natural vibration frequency can be increased, the occurrence of vibration due to the natural vibration of the mirror can be prevented, and compared with the case where the reinforcing material is attached to the back surface of the mirror In addition, the flatness of the reflecting surface of the mirror can be maintained fairly accurately, and image distortion and magnification error due to deterioration of the flatness can be prevented while suppressing image shaking and poor resolution due to mirror vibration. .

According to the second aspect of the present invention, in the first aspect of the present invention, the reinforcing member has a thermal expansion coefficient substantially equal to that of the mirror substrate. Since the displacement of the bonded portion does not occur, the deformation of the mirror and the peeling of the adhesive due to the displacement of the bonded portion do not occur.

According to the third aspect of the present invention, in the first or second aspect of the present invention, the reinforcing member and the optical turn-back mirror are adhered with a double-sided tape having elasticity, so that the temperature of the surrounding member changes with a change in ambient temperature. The difference in the thermal expansion coefficient between the mirror and the double-sided tape or between the reinforcing member and the double-sided tape can solve the problem that the mirror and the reinforcing member are displaced, and the mirror is deformed or the adhesive is peeled off.

According to the fourth aspect of the present invention, in the first or second aspect of the invention, the reinforcing member and the light turning mirror are bonded at a plurality of positions in the longitudinal direction of the light turning mirror. The bonding area between the mirror and the reinforcing member can be reduced, and the mirror and the reinforcing member are displaced due to the difference in the coefficient of thermal expansion between the mirror and the double-sided tape or the reinforcing member and the double-sided tape due to changes in the surrounding temperature. Problems such as deformation and adhesion peeling can be solved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an optical turning mirror according to the present invention.

FIG. 2 is a perspective view showing another example of the optical turning mirror according to the present invention.

FIG. 3 is a side view showing an example of an image forming apparatus to which the optical turning mirror according to the present invention can be applied.

FIG. 4 is a side view showing an example of a scanner device to which the optical turning mirror according to the present invention can be applied.

FIG. 5 is a side view showing another example of the scanner device.

FIG. 6 is a perspective view showing an example of a conventional light turning mirror.

FIG. 7 is a side view showing an example of a conventional light turning mirror.

[Explanation of symbols]

 21 Optical turning mirror 24 Double-sided tape 34 Reinforcing member

Claims (4)

[Claims] 1. An image forming apparatus, such as a copying machine, wherein a reinforcing member is adhered to one or both sides of a side surface along a longitudinal direction of a light turning mirror substrate for turning light reflected from a document. Folding mirror. 2. The optical folding mirror according to claim 1, wherein the reinforcing member has a thermal expansion coefficient substantially equal to that of the mirror substrate. 3. The optical folding mirror according to claim 1, wherein the reinforcing member and the optical folding mirror are adhered with a double-sided tape having elasticity. 4. The optical folding mirror according to claim 1, wherein the reinforcing member and the optical folding mirror are bonded at a plurality of positions in a longitudinal direction of the optical folding mirror.