JP2889671B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving frame equipped with an optical system for scanning in an image forming apparatus such as a copying machine, an image scanner, and a document reading apparatus. The present invention relates to an image forming apparatus provided with a movable frame of an optical system that is slidably supported at two points on one of a pair of support bases arranged in parallel and at one point on the other support base.

[Problems to be solved by the prior art and the invention]

FIG. 5A shows a moving frame of a copying machine as an example of this type of image forming apparatus.

In FIG. 1, for example, a first moving frame 30 incorporating a light source (not shown) for exposing a document is supported on a pair of support tables 2 and 3 arranged in the copier body side in a direction perpendicular to the paper surface. ing. In the first moving frame 30, one slider 34 made of easily slidable resin protruding from the lower surface thereof is supported on one of the support bases 3, and along the support bases, the first moving frame 30 is provided. Two sliders 35 connected to the lower surface of 30 are supported on the other support 2. That is, the first moving frame
Reference numeral 30 is slidably supported on the support bases 2 and 3 at three points in plan view. Similarly, a second movable frame incorporating a mirror (not shown) is supported on the support bases 2 and 3 on the back side of the first movable frame 30 in the direction perpendicular to the paper by a slider which is also supported at three points in a plan view. ing. When an optical system mounted on such a moving frame is used to form an image of reflected light from the light source through a lens or the like on a reading sensor, for example, when adjusting the optical axis on the mirror, for example, the, as shown in FIG. 5 (b), generally the center of the light distribution on the mirror as viewed from the reading sensor (hereinafter, referred to as light distribution center C) to match the optical axis L ₁ in Thus, the mounting angle of, for example, a mirror is adjusted.

However, since each of the moving frames is supported at three points in plan view, the slider 35 on the two-point support side and the slider 34 on the one-point support side are supported.
The respective wear rates differ between and due to the difference in the supporting load.
Therefore, for example, as the first moving frame 30 is used over time, the one-point support side is inclined downward (indicated by a two-dot chain line in FIG. 5A). The same applies to the second moving frame. In this state, the optical axis L ₁ is shifted from the light distributing center C, the state shown by the two-dot chain line L ₂ in FIG. 5 (b). In the copying machine, the allowable range R ₃ with respect to deviation of the optical axis _L1 is set. in this way,
Above copying machine, with the difference in wear rate occurs slider 1-point support side and the two-point support side slider in the individual movable frame, since the optical axis L ₁ is initialized to the light distribution center C In some cases, the output of the reading sensor becomes not flat with time in the main scanning direction, which may affect, for example, the perpendicularity of a transfer image formed on transfer paper.

Accordingly, a first object of the present invention is to provide an image forming apparatus capable of correcting the deviation of the optical axis passing through the movable frame with the lapse of time during the machine life.

In a copying machine provided with the first moving frame and the second moving frame as described above, for example, a two-point support side of each of the above-mentioned moving frames is arranged on a support base 2 and the other of the respective one-point support sides is provided. When the moving frames are arranged closest to the support table 3, the two-point supporting sides which are relatively wide in the sub-scanning direction are connected when the moving frames are closest to each other, so that a large space in the sub-scanning direction is required.
Therefore, as shown in FIG. 6, the first moving frame 30 and the second moving frame 31 are alternately moved in the sub-scanning direction (arrow S) in which the two-point support side and the one-point support side are sliding directions. Some are supported on the support bases 2 and 3 as shown in FIG. Such a copying machine has the advantage that when the first moving frame 30 and the second moving frame 31 are closest to each other, the space occupied by them can be made compact. Also in such a copying machine, the optical axis passing through each moving frame is often initially set to the respective light distribution centers.

However, in a copying machine in which the two-point support side and the one-point support side are alternately provided in the sub-scanning direction for each moving frame as described above, in the first moving frame and the second moving frame, the main scanning direction is used. , The opposite sides incline with use over time. For this reason, the relative deviation of the optical axis between the moving frames increases synergistically with use over time. Also, the deviation of the optical axis at this time is also in the direction away from the light distribution center. As a result, for example, the distortion of the image formed on the transfer paper tends to increase.

Accordingly, a second object of the present invention is to take advantage of the compact configuration of the moving frame of at least two optical systems, and to pass through each of the moving frames with the passage of time during the machine life. An object of the present invention is to provide an image forming apparatus capable of correcting a deviation of an optical axis.

[Means for solving the problem]

The main means employed by the first invention to achieve the first object is that the gist of the invention is that two points are provided on one of a pair of supports arranged in parallel and the other is provided on the other. In an image forming apparatus comprising a movable frame of an optical system slidably supported at one point on a support base, the one side supporting side of the movable frame is worn within an allowable range of wear of the movable frame. The image forming apparatus is configured as an image forming apparatus according to a point deviated in advance in a direction opposite to the direction.

The main means employed by the second invention to achieve the second object is that the gist of the invention is that two points are provided on one of a pair of supports arranged in parallel and the other is provided on the other. A movable frame of at least two optical systems which are slidably supported at one point on the support table, and each movable frame is moved between the two-point support side and the one-point support side in the sliding direction. In the image forming apparatus which is arranged alternately on the support table, a point at which one point of each of the moving frames is deviated in advance in a direction opposite to a wear direction within an allowable range of the wear of the moving frame. As an image forming apparatus according to the present invention.

[Action]

According to the first aspect, since the one-point support side of the moving frame is deviated in advance in a direction opposite to the wear direction within an allowable range of the wear of the moving frame, the moving frame passes through the moving frame. The corresponding optical axis is also deviated within the permissible range corresponding to the one-point support side. When such a moving frame is used for a long time, generally, the wear rate of the one-point support side is faster than that of the two-point support side, and the deviation amount on the one-point support side decreases with the above-mentioned time use, and at the same time, The deviation of the optical axis is also reduced.

According to the second aspect of the present invention, the one-point support side of each moving frame is preliminarily deviated in the direction opposite to the wear direction within the allowable range of the wear of the moving frame. With use, each one-point support side wears more than its two-point support side. Therefore, the deviation of the optical axis passing through these moving frames is corrected over time. As a result, the problems caused as a result of downsizing the configuration relating to each of the moving frames are eliminated.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. FIG. 1 is a schematic configuration diagram partially showing a copying machine according to an embodiment of the present invention, and FIG. 2 is a perspective view showing an arrangement state of a first moving frame and a second moving frame of the copying machine. FIG. 3 is an explanatory view of the progress of the optical axis of the reflected light passing through the first moving frame and the second moving frame as viewed from the side, and FIG. FIG. 3B is a state explanatory view showing an optical axis on a mirror below the second moving frame, and FIG. 4B is a state explanatory view showing an optical axis on a mirror above the second moving frame viewed from the reading sensor; FIG. 3C is a state explanatory view showing the optical axis of the first moving frame on the mirror as viewed from the reading sensor.

Copier 1 according to this embodiment, as shown in FIG. 1, the upper portion of the main body 15, a first movable frame 10 mounted with the light source 12, a second mobile equipped with a set of mirrors 13, 13 _a A frame 11 is provided. In the copying machine 1, the first moving frame 10 and the second moving frame 11 move in the sub-scanning direction (arrow S), and
Been exposing and scanning the document (not shown) placed on top, the reflected light from the original through the mirrors 43,13,13 _a, a lens 41, etc., an original image by the reading sensor 17 consisting of a CCD line sensor As light. A toner image corresponding to the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 18 is formed on the transfer paper P based on the image output from the reading sensor 17.

As shown in FIG. 2, the first moving frame 10 is fixed to, for example, a side plate 40 on the main body side, and is supported by integral support bases 2, 3 arranged in parallel in the sub-scanning direction (arrow S). Have been.
Two sliders 5 and 6 made of synthetic resin protrude downward from the end of the first moving frame 10 on the support table 2 side and are connected in the sub-scanning direction. On the other hand, one slider 4 is provided at the end of the support base 3 so as to protrude toward the other. That is, the first moving frame 10 is provided with the slider 4 on the support 3.
Are slidably supported at one point, and are slidably supported at two points on the support base 2 by sliders 5 and 6.

On the upper surface of the first moving frame 10, a slit 42 for guiding reflected light emitted from the light source 12 from the original to a mirror 43 provided in the first moving frame 10 is provided in the main scanning direction (arrow). M).

The second moving frame 11 is also provided with sliders 7, 8, 9 made of synthetic resin at the respective ends on the support bases 2, 3 side, protruding downward, and these sliders 7, 8, 9 Second moving frame 1
1 is slidably supported on the supports 2 and 3. In this case, the sliders 8 and 9 are placed on the support 3 and the sliders 7 and
Are supported on a support base 2. That is, the first moving frame
The 10 and the second moving frame 11 are arranged on the supports 2 and 3 such that the two-point support side and the one-point support side alternate in the sliding direction thereof. Thus, each moving frame 10,
If the movable frames 10 and 11 are closest to each other, the 11 is placed on each of the supports 2 and 3 so that the two-point support side and the one-point support side alternate in the sliding direction. In addition, the configuration becomes compact in the sliding direction.

The first moving frame 10 is moved by the wire 14 wound around the plurality of pulleys 20 to 27 in the sub-scanning direction at twice the speed of the second moving frame 11 by twice the distance. ing.

In the moving frame 10, the slider 42 on the one-point support side is provided to be longer than the sliders 5 and 6 on the two-point support side. Also, in the moving frame 11, the one-point supporting side
Is provided to be longer than the sliders 8 and 9 on the two-point support side. This is because the wear speed is generally faster on the one-point support side than on the two-point support side. That is, the one-point support side of each of the moving frames 10 and 11 is
It is preliminarily deviated in the direction opposite to the wear direction within the allowable range of wear of 0,11.

The allowable range of the wear of the moving frames 10 and 11 is the allowable range of the optical axis on the mirrors 13, 13 _a and 43 and the slit 42 as viewed from the reading sensor 17 (R _{1 in} FIG. 4A). , The same figure (b)
R ₂ , and R ₄ ) in FIG. Further, the allowable range of the optical axis refers to the allowable range of the optical axis in which the squareness representing the distortion of the transferred image with respect to the original image should be within the allowable range.

FIG. 3 shows the progress of the optical axis of light reflected by the light source 12 and reflected from a document or the like in the copying machine 1 configured as described above. In the figure, mirrors 13, 43
The hatching attached to indicates the back of each mirror. In this case, the rear side of the mirror 43 can be seen because the second moving frame 10 is highly displaced on the near side in the direction perpendicular to the paper surface. Also, so that the second moving frame 11 is visible and the mirror surface of the back and the mirror 13 _a of the mirror 13 so that the direction perpendicular to the plane rear side is made higher offset.

Accordingly, the optical axis L ₁₁ of the reflected light, when viewed from the reading sensor 17 in the mirror 13 _a of the second moving frame 11, as shown in 4 (a), the support base 3 side in the mirror 13 _a It will have been displaced in the opposite direction also in advance sub-scanning direction thereof within the allowable range R ₁ from the light distribution center C.

On the other hand, in the mirror 13 of the second moving frame 11, when viewed from the reading sensor 17, as shown in FIG. 4 (b), the optical axis L ₂₁ than the light distribution center C of the support base 2 side mirror 13 also that is offset in advance in the sub-scanning direction thereof within the allowable range R _2. As a result, when viewed from the reading sensor 17 in the mirror 43 of the first movable frame 10, as shown in FIG. 4 (c), the optical axis L ₃₁ is the support base 2 side sub-scanning direction, the support base 3 side reaction Each light beam is deviated from the light distribution center C in the sub-scanning direction. Further, the slit 42 of the first moving frame 10 is
The optical axis L ₄₁ when viewed from the 17 shown in FIG. 4 (d). Aspects of the deviation from the light distribution center C of the optical axis L ₄₁ is the same as that of the optical axis L ₃₁ in the mirror 43 described above. Then, the optical axis L ₄₁ in the above deviation is within the allowable range R ₄ which is set in advance for the optical axis L _41.

Therefore, in the mechanical initial use of the copying machine 1 as described above, the slider 4 and 7 of the one-point support side of the movable frame 10, 11 is not worn, the slit 42 and the mirror 13, 13 _a, 43 The optical axis at is also deviated in accordance with the inclination of each of the moving frames 10 and 11.

Therefore, in this case, the squareness of the image transferred onto the transfer paper P is shifted from the normal state, but the degree of the squareness shift is within the allowable range, and there is no problem.

Subsequently, when the copying machine 1 is used over time, the slider 42 on the one-point support side of the moving frame 10 wears more than the sliders 5 and 6 on the two-point supporting side. The slider 7 on the side wears more than the sliders 8, 9 on the two-point support side. Thereby, the one-point support side of each of the moving frames 10 and 11 gradually lowers with time. Accordingly, the optical axis L ₁₁ on the mirror 13 _a and the optical axis L on the mirror 13
₂₁ , the optical axis L ₃₁ on the mirror 43 and the optical axis L _{41 on the} slit 42 gradually approach the respective light distribution centers C. Thereby, the squareness of the transferred image output as an output signal from the reading sensor 17 gradually increases.

Furthermore, the first movable frame 10 and the second moving frame 11 is, in these machines lifetime, the position of two-dot chain line optical axis ₄₁ is within the allowable range R ₄ in the slit 42 as viewed from the reading sensor 17 (first 4 (d)). Therefore,
If the deviation of the perpendicularity is not taken into account, the first and second
Since the moving frames 10 and 11 are used over the entire allowable range of wear, they have a longer life than conventional ones.

As described above, in the copying machine 1 according to the present embodiment, one point supporting side of the first moving frame 10 and the second moving frame 11
The movable frames 10 and 1 are configured so as to be deviated in advance in the direction opposite to the wear direction within the allowable range of wear of 0 and 11.
In order to make the configuration according to 1 compact, these moving frames 10,
11 is the result of arranging the two-point support side and the one-point support side on the supports 2 and 3 alternately in the sub-scanning direction. 10,11
The problem that the deviation of the optical axis passing through the optical path becomes large can be solved.

In the present embodiment, the first moving frame 10 and the second moving frame 11 are supported on the support bases 2 and 3 via the respective sliders 4 to 9, but the present invention is not limited to this. The present invention can also be applied to a case where the first and second moving frames are supported upward on the lower surfaces of the supports 2 and 3.

Further, in the copying machine 1 of the above-described embodiment, each one-point support side of the first moving frame 10 and the second moving frame 11 is deviated in advance in a direction opposite to the wear direction. 1
It is not necessary to deviate both the point support sides, and only one point support side of one of the moving frames may be deviated as described above.

〔The invention's effect〕

According to the first aspect of the invention, the movement of the optical system is slidably supported at two points on one of the pair of support tables arranged in parallel and at one point on the other support table. In the image forming apparatus provided with a frame, the one-point support side of the moving frame is previously displaced in a direction opposite to a wear direction within an allowable range of the wear of the moving frame. Is provided. Thereby, the deviation of the optical axis passing through the moving frame is corrected with the aging use during the machine life.

According to the second aspect of the present invention, at least two slidably supported two points on one of the pair of support bases arranged in parallel and one point on the other support base are slidable. An image forming apparatus comprising: a moving frame for two optical systems, wherein each of the moving frames is alternately arranged on the support table in the sliding direction on the two-point support side and the one-point support side. An image forming apparatus is provided, wherein the one-point support side of the moving frame is displaced in advance in a direction opposite to the wear direction within an allowable range of the wear of the moving frame. Thereby, taking advantage of the compact configuration of the moving frame of at least two optical systems, and with the use over time during the machine life,
The deviation of the optical axis passing through these moving frames can be corrected.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram partially showing a copying machine according to an embodiment of the present invention, FIG. 2 is a perspective view showing an arrangement state of a first moving frame and a second moving frame of the copying machine, and FIG. FIG. 4 is an explanatory view of the progress of the optical axis of reflected light passing through the first moving frame and the second moving frame as viewed from the side, and FIG. 4A is a second moving frame viewed from a reading sensor of the copying machine. FIG. 4B is a state explanatory view showing an optical axis on a mirror below the lower part of FIG.
FIG. 4C is a state explanatory view showing the optical axis on the mirror above the moving frame, FIG. 5C is a state explanatory view showing the optical axis on the mirror of the first moving frame viewed from the reading sensor, and FIG. FIG. 5 (a) is a state explanatory view showing an optical axis in a slit of the first moving frame viewed from the reading sensor, and FIG. 5 (a) shows a moving frame of an optical system of a conventional copying machine, which is an example of the background of the present invention, arranged in parallel. Schematic diagram showing a state of being supported on a pair of supported supports,
FIG. 2B is an explanatory view of the optical axis of the slit formed in the moving frame as viewed from the reading sensor. FIG. 6 shows the arrangement of the first moving frame and the second moving frame of the conventional copying machine. It is the schematic diagram seen from the plane. [Description of Signs] 1... Copier 2, 3... Support 4, 5, 6, 7, 8, 9… Slider 10… First moving frame 11… Second moving frame 12… Light source 13 , 13 _a , 43 …… Mirror 42 …… Slit

Claims (2)

(57) [Claims] 1. A moving frame for an optical system, which is slidably supported at two points on one of a pair of supporting stands arranged in parallel and at one point on the other supporting stand. The image forming apparatus according to claim 1, wherein the one-point support side of the moving frame is displaced in advance in a direction opposite to a wear direction of the moving frame within an allowable range of the wear of the moving frame. 2. A moving frame for at least two optical systems which are slidably supported at two points on one of a pair of supporting stands arranged in parallel and at one point on the other supporting stand. Wherein each of the moving frames is provided with the two-point support side and the one-point support side alternately arranged on the support table in the sliding direction. An image forming apparatus, wherein the side is displaced in advance in a direction opposite to a wear direction within an allowable range of wear of the moving frame.