JP2003241131A - Deflecting scanner and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deflecting scanner and an image forming device which are improved in adjustment precision and make adjusting operation efficient while using inexpensive components, hardly have the changes with time, and are highly reliable. <P>SOLUTION: The position of an optical box 1 with respect to an image forming device main body frame 60 is adjusted with an adjusting member fitting part 501a provided in the outer edge part of the main body of the optical box 1 and a wedgelike adjusting member 51. In the adjusting member 51, a bolt 51b is buried which extends in the direction of fitting to the adjusting member fitting part 501a. The Xs-directional relative positions of the adjusting member 51 and adjusting member fitting part 501a are adjusted and a nut 52 is threadably engaged with the bolt 51b which penetrates a long hole 5011a of the adjusting member fitting part 501a and is exposed on the surface side to fix the adjusting member 51 to the optical box 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection scanning device used in an image forming apparatus such as a laser beam printer, and is particularly suitable for accurately adjusting a position when a scanning line is irradiated on a surface to be scanned. The present invention relates to a deflection scanning device, and is suitable for a system that forms a color image at a high speed by using a plurality of deflection scanning devices and image carriers, which has become widespread and low in price in recent years.

[0002]

2. Description of the Related Art Many deflection scanning devices used in laser beam printers and the like are unitized in consideration of exchangeability and ease of maintenance. For mounting the deflection scanning device on the image forming apparatus main body, for example, a fixing portion provided on the deflection scanning device is placed on a mounting seat surface formed on the main body and fixed by a fixing means such as a screw. It is common to do. Such a deflection scanning device is manufactured so as to exhibit a predetermined performance in the state of a unit by performing necessary adjustments by itself, but it remains the same even after it is incorporated in the image forming apparatus main body. In order to maintain the performance, it is necessary to improve the component accuracy of both the deflection scanning device and the image forming apparatus main body. Further, in such a deflection scanning device, it is particularly important to maintain an accurate positional relationship between the scanning line and the surface to be scanned of the image forming apparatus main body. In many cases, the deflection scanning device for that purpose has an adjusting member for adjusting the inclination of the scanning line.

A conventional mechanism for adjusting the inclination of the scanning line will be described below.

FIG. 5 shows a scanning line inclination adjusting mechanism of a conventional deflection scanning device known from Japanese Patent Laid-Open No. 2000-249953.
This is a wedge-shaped part 114 as a fixing part height adjusting means.
By deforming the optical box 10, the inclination of the scanning line can be easily adjusted to a desired inclination.

Further, in the device disclosed in Japanese Patent Laid-Open No. 5-119276, a screw (adjustment foot) for adjusting the seating surface height is provided at two of the three fixing portions in which mounting holes are formed in the optical box. ) Are provided, and the seat height of the optical box can be adjusted by the screws.

Therefore, a detailed description of these conventional examples and adjustment by the adjusting member will be described below.

FIG. 6 shows the configuration of a general deflection scanning device 200.

Laser light L emitted from the light source unit 202
Is applied to the rotary polygon mirror 205 of the scanner motor 204, and the rotary polygon mirror 205 is rotated to deflect and scan the laser light L, and the scanned surface 207 of the photoconductor, which is an image carrier, passes through the scanning lenses 206a and 206b. An image is formed as a scanning line 208 on the. The scanning line 208 is formed by a series of light spots.

A plurality of fixing portions 250 are provided on the outer edge of the optical box, are mounted on the main body frame 260 of the image forming apparatus with high accuracy, and the main body frame 26 is fixed by a deflection scanning device fixing means (not shown).
It is held in close contact with 0. In the case of the present embodiment, the arrow Z direction in the figure is the direction in which accuracy is required on the image carrier, and the optical box is mounted on the main body frame 260 in the same Z direction. It is necessary to reduce or adjust the height error when placing the box. In this example, there are three fixing portions, and they are brought into contact with each other in a stable plane state.

In FIG. 6, one of the fixing parts 250 is provided with an adjusting member 251.
Is provided, and after adjusting the relative position with respect to the optical box, it is securely fixed to the optical box with a screw 252 as a fixing member.

FIG. 7A shows a "scan line without inclination" 208.
In the figure, (b) shows a state with "tilt". For example, in a method of forming a color image at a high speed using a plurality of deflection scanning devices and image carriers, it is necessary to overlap the scanning lines, but in the state shown in FIG. 7C, the scanning lines do not overlap and are displaced. I understand.

Next, adjustment of these conventional deflection scanning devices will be described with reference to FIG.

Laser light L emitted from the light source unit 202
Is applied to the rotary polygon mirror 205 of the scanner motor 204, and the rotary polygon mirror 205 is rotated to deflect and scan the laser light L, and the adjusting member 251 is moved relative to the optical box at Xs in the figure.
Shift in the direction of. At this time, the scanning line 208 is the +, − in FIG.
It changes like a sign. This is because the adjusting member 251 and the optical box are in contact with each other on a slope as shown in FIG. 9 and the adjusting member 251 has a wedge shape, so that the height of the fixing portion 250 of the optical box is changed.

Then, the sensor 210 placed on the surface 207 to be scanned in FIG. 8 is irradiated with this scanning line. Sensor 210 is line
This is called a CCD sensor. Light receiving elements are arranged in a line in the direction of arrow Z in FIG. 8 and the position of incident light can be measured. Here, the line CCD sensor is 210 (L), 210 (C), 2
There are three 10 (R), and the obtained position information is Z respectively.
When defined as (L), Z (C), and Z (R), the scanning line 208
The adjustment of the “tilt” of is given by the following equation with positional information of both ends. Z (L) -Z (R) = Slope

As a result, a change in the positional relationship between the optical box and the surface to be scanned can be detected. Therefore, when the optimum state (specifically, inclination = 0) is reached, the adjusting member 251 is fixed with the screw 252. For fixing, a screwdriver is set along the axis Ys, and a screw is passed through the oblong hole on the optical box side and passed through the prepared hole of the adjusting member 251 and tightened. By adopting such an adjusting method, the optical box and the adjusting member are surely integrated with 251. Since the tilt of the deflection scanning device is adjusted to "nearly zero" and unitized, the replaceability and maintenance are easy.

Particularly, in recent years, a method of forming a color image at a high speed by using a plurality of optical scanning devices and a plurality of image carriers has become widespread and the price has been reduced, and the "tilt" accuracy of the scanning line is "nearly zero".
Specifically, the demand has been increasing until the “deviation of several tens of μ or less” is achieved.

[0017]

However, the above-mentioned conventional example has the following problems.

In Japanese Patent Laid-Open No. 2000-249953, since the optical box 100 is deformed by the wedge-shaped component 114, it is inevitable that the original optical performance is slightly deteriorated. In particular, it is not sufficient to achieve the "deviation of tens of μ or less". Furthermore, since the adjustment parts are not fastened to the optical box,
Not suitable for unit replacement. In JP-A-5-119276, the adjustment component is fixed to the optical box side.
In particular, the workability and the configuration necessary for achieving "a deviation of several tens of μ or less" are not described. In recent years, it is desirable to use a thermoplastic resin (plastic molded product) that can be mass-produced and is inexpensive as the material of the optical box, but in the case of molded products, stable mass-production (adjustment) while maintaining the required accuracy. However, these conventional configurations are insufficient.

The use of self-tapping screws as fixing means is also described in these prior art examples, but in this case as well, there was a problem as shown in FIG. That is, a large torque T is required for self-tapping, and a large axial force W also needs to be added in the Ys direction so that the bit of the driver does not rotate after it is disengaged from the screw header. Such a large T and W easily elastically deforms about several tens of μ unless the optical box and the adjusting member are made of expensive metal. In other words, even if the tilt adjustment is within the standard with T and W applied during the adjustment, the distortion returns as soon as the driver is released, and the standard is greatly exceeded. Moreover, since such a state of distortion is very difficult to stabilize, in which friction and slippage are mixed, reproducibility is poor and workability is significantly deteriorated even if readjustment is performed. Furthermore, distortion and stress remain even if the driver is released and fortunately meets the specifications, and the residual deflection distortion is released by transporting the completed deflection scanning device and applying vibration or temperature change. However, what was carefully adjusted fluctuated over time and impaired reliability.

The present invention has been made in order to solve the problems of the prior art. The purpose of the present invention is to improve the adjustment accuracy and make the adjustment work efficient while using inexpensive parts. It is an object of the present invention to provide a deflection scanning device which is less likely to change over time and has high reliability, and an image forming apparatus using the same.

[0021]

To achieve the above object, the present invention provides a light source unit, a unit for deflecting and scanning a light beam from the light source unit, and a light beam deflected by the deflection scanning unit on a surface to be scanned. A light source unit, a deflection scanning unit, and an optical box for accommodating the scanning and image forming unit. The optical box is provided on a supporting portion of the frame body of the image forming apparatus. The optical box is supported, and the optical box has a fixing section fixed to the supporting section, and at least one of the fixing sections adjusts a positional relationship between the optical box and the supporting section. In the deflection scanning device, which is an adjustable fixing unit having an adjusting member mounting portion provided on the optical box body and a fixing means for fixing the adjusting member to the adjusting member mounting unit, the adjusting member includes the adjusting member. The direction fixed to the member mounting part is the reference axis Te, by the operation of applying a force in a substantially orthogonal plane to the reference axis to said fixing means, the adjusting member is a deflection scanning apparatus characterized by being fixed to the adjusting member mounting portion.

As a result, it is possible to suppress deformation of parts during adjustment, and it is possible to employ an inexpensive plastic molded product even in a highly accurate deflection scanning device.

The adjusting member mounting portion has a guide groove for guiding the adjusting member, and the adjusting member faces the adjusting member mounting portion and is arranged in a direction in which the optical box is supported by the supporting portion. It is possible to adjust the positional relationship between the optical box and the support portion by moving the adjusting member along a surface facing the adjusting member attachment portion according to the guide groove and having a surface inclined with respect to the guide groove. It is suitable.

As a result, the movement of the adjusting member is stable, the shape of the parts can be simplified, and quick adjustment and cost reduction are possible.

It is preferable that the fixing means is a screwing means that is screwed through the adjusting member mounting portion.

It is preferable that the screwing means includes a bolt provided on the adjusting member and extending along the reference axis, and a nut screwed to the bolt.

As a result, a more inexpensive component structure can be obtained.

It is preferable that the screwing means includes a screw hole formed in the adjusting member along the reference axis and a bolt screwed into the screw hole.

It is preferable that the fixing means includes a protrusion provided on the adjusting member and having a through hole in a direction substantially orthogonal to the reference axis, and a wedge-shaped member penetrating into the through hole. .

Further, according to the present invention, an image carrier having a photoconductive layer, a light source section, means for deflecting and scanning a light beam from the light source section, and a light beam deflected by the deflection scanning means on the image carrier. In an image forming apparatus including a scanning image forming unit for irradiating a scanning line as a scanning line, and an optical box containing the light source unit, a deflection scanning unit, and a scanning image forming unit, the frame body of the image forming apparatus main body is the optical unit. The optical box has a supporting part for supporting a box, the optical box has a fixing part fixed to the supporting part, and at least one of the fixing parts is composed of the optical box and the supporting part. An adjustable fixing portion having an adjusting member for adjusting a positional relationship, an adjusting member mounting portion provided on the optical box body, and a fixing means for fixing the adjusting member to the adjusting member mounting portion, the adjusting member Is fixed to the adjustment member mounting part As collimation axis, by an operation of applying a force in a substantially orthogonal plane to the reference axis to said fixing means, the adjusting member is an image forming apparatus characterized by being fixed to the adjusting member mounting portion.

The material of the adjusting member may be the same as that of the optical box.

The fixing means is preferably made of metal.

The scanning and image forming means may be a diffractive optical element.

The scanning and image forming means may be moved in parallel along an axis along the longitudinal direction to adjust the one-side magnification in the main scanning direction on the surface to be scanned.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiments.

FIG. 1 is a diagram showing a deflection scanning device according to an embodiment of the present invention. A plurality of fixing parts 5 are provided on the outer edge of the optical box 1.
0a, 50b, 50c are provided, are mounted with high precision on the main body frame (supporting portion) 60 of the image forming apparatus such as a laser beam printer, and are closely attached to the main body frame 60 by a deflection scanning device fixing means (not shown). Held in a state. A light source unit (light source unit) 2 is attached to the optical box 1, and a scanner motor 4 is arranged in the traveling direction of the laser light L emitted from the light source unit 2. A rotary polygon mirror (deflection / scanning means) 5 is attached to the scanner motor 4, and scanning lenses (scanning / imaging means) 6a and 6b are optical in the traveling direction of the laser beam L deflected and scanned by the rotary polygonal mirror 5. Arranged inside the box 1, the laser light L is imaged as scanning lines 8 on the surface to be scanned 7 of the photoconductor as an image carrier having a photoconductive layer. The scanning line 8 is formed by a series of light spots. Here, the fixed portion 50a corresponds to the adjustable fixed portion.

Since a known method can be used for the image forming processing in the image forming apparatus equipped with the deflection scanning device according to the present invention, the details will be omitted.

Next, the tilt adjustment of this deflection scanning device will be described.

The adjustable fixing portion 50a includes an adjusting member mounting portion 501a on the main body side of the optical box 1 and an adjusting member 51. The adjustment member attachment portion 501a is provided on the outer edge portion in the extension direction of the scanning line. Further, the adjustment member attachment portion 501a has a groove (guide groove) having a substantially U-shaped cross section that opens toward the adjustment member 51 side. The bottom surface of the groove of the adjustment member attachment portion 501a is inclined with respect to the supporting direction of the frame body 60, and a long hole 5011a extending in the inclination direction is formed. The adjustment member 51 has a wedge shape in which a portion 51s facing the bottom surface of the groove of the adjustment member attachment portion 501a forms an inclined surface inclined with respect to the supporting direction of the optical box 1 to the frame body 60.

The laser light L emitted from the light source unit 2 is
The rotary polygon mirror 5 of the scanner motor 4 is irradiated with the rotary polygon mirror 5.
Is rotated to shift the adjusting member 51 in the direction of Xs in the figure with respect to the optical box 1 while the laser beam L is being deflected and scanned. And the sensor 10 placed at the position corresponding to the photoconductor
This scanning line is irradiated to the. Up to this point, it is the same as the conventional example. The operation of the CCD sensor is the same as that of the conventional example and will not be described.

Here, the present embodiment is different from the conventional one in the following points.

That is, in the fixing portion 50a, when the adjusting member 51 is fixed to the optical box 1 with the nut 52 as shown in FIG. 2, when the direction Ys fixed to the optical box 1 is used as a reference axis,
That is, the nut 52 is used as a rotating and fixing means by the nut turning 53 that engages only in the direction of rotation around Ys.

Next, the specific operation will be described in detail.

First, in FIG. 2 (a), the adjusting member 51 is entirely made of a molded product of the same material as the optical box 1, but a metal bolt 51b is embedded in the central portion. This bolt 51b
May be insert-molded as an insert metal fitting when molding the adjusting member 51, or may be molded with a shape having only a hole for receiving the bolt 51b at the time of molding, and later the bolt 51b.
May be press-fitted. By doing so, it is possible to fix with a torque T much smaller than that of a self-tapping screw or the like. The bolt 51b embedded in the adjusting member 51 is
When 1 is set in the adjusting member mounting portion 501a, it penetrates through the elongated hole 5011a of the adjusting member mounting portion 501a and is exposed on the front surface side.

Next, when the adjusting member 51 is set on the adjusting member mounting portion 501a of the optical box 1 and moved in the Xs direction, the adjusting member 51 is moved.
Since the adjustment member attachment portion 501a of the optical box 1 is in contact with the slope and the adjustment member 51 has a wedge shape, the height of the adjustment member attachment portion 501a of the optical box 1 is changed and the inclination of the scanning line is also changed. Then, when the inclination enters a desired standard value, the adjusting member 51 is fixed to the optical box 1 in that state, but here, the nut 52 is engaged with the bolt 51b from the surface side of the adjusting member attaching portion 501a, Turn 53 to tighten. As shown in Fig. 2 (b), the tip of the nut driver 53 as a work tool is a hexagonal recess having the same outer shape as the nut. The nut 52 engages in the rotating direction but transmits any force in the axial direction. Do not have such contact. As a result, the torque T itself can be fixed even if it is sufficiently small, and there is no axial force W. Therefore, the fixing work can be completed with almost no deformation of the optical box 1 and the adjusting member 51, and no stress or strain remains after the completion. Is possible. Since the nut 52 and the nut driver 53 are hard to rotate idle, workability is good, and it is also preferable that the press-fitted bolt 51 can be relatively easily extracted from the main body of the adjustment member 51 of the molded product when disassembled for recycling. .

Further, the above-mentioned adjusting method according to the present invention is not limited to the "inclination" adjusting method of the scanning line.
In configuring a high-precision deflection scanning device by applying a plastic molded part, other adjustments, for example, as shown in FIG. 3A, the fixing unit 50b of the deflection scanning device shown in FIG. 1 has the same configuration. By applying "Adjust the height of the entire scanning line"
Of course, it is also effective for such cases. Here, when the fixed portion 50b is rotated about the line connecting the fixed portion 50a and the fixed portion 50c as the center of rotation, the scanning line 8
The whole moves in parallel in the Z direction (see FIG. 3 (b)). By doing so, the height of the entire scanning line can be adjusted.

Although the fixing member has been described as an example of the hexagonal nut in the above embodiment, the present invention is not limited to this. A modified example of the fixing member is shown in FIG.

As shown in FIG. 4A, a female screw 51c may be insert-molded on the adjusting member 51 side, and a hexagon bolt 521 may be used as a fixing member. Also in this case, the hexagon bolt can be rotated by rotating the shaft in the direction shown by the arrow in FIG.
The optical box 1 can be fixed to the adjusting member 51 by engaging the female screw 521.

Further, as shown in FIG. 4B, the adjusting member
The bolt 51b may be embedded in the 51 side, and the fixing member that is screwed into the bolt 51b may be a plate nut 522 obtained by processing a female metal on a metal plate. Also in this case, the plate-shaped nut 522 can be engaged with the bolt 51b and the optical box 1 can be fixed to the adjustment member 51 by the rotation operation in the direction around the axis shown in FIG.

Further, as shown in FIG. 4C, the protrusion 511 provided on the adjustment member 51 side may be engaged with the wedge-shaped fixing member (cotter) 523. The protruding portion 511 is formed so as to protrude on the slope of the adjustment member, and the through hole 511a is formed in a direction orthogonal to the slope of the slope. Adjustment member mounting part 501a
The through hole 51 of the protruding portion 511 exposed on the surface side from the long hole 5011a of
The optical box 1 is fixed to the adjusting member 51 by inserting a wedge-shaped fixing member 523 longer than the width of the long hole into the la 1a. Also in this case, as shown in FIG.
The optical member 1 can be fixed to the adjusting member 51 by engaging the fixing member 523 with the protruding portion 511 by a penetrating operation in a direction orthogonal to the direction in which the optical member 1 is fixed.

As described above, the modified examples shown in FIGS. 4A to 4C are also included in the concept of the present invention.

[0052]

As described above, according to the present invention,
Fast and accurate adjustment of the scan line inclination using inexpensive parts such as plastic molded parts, and also prevent the effects of fixing, elastic deformation of members, friction between members, stick slip, etc. No residual stress afterwards,
It is possible to provide a highly accurate and highly reliable deflection scanning device and an image forming apparatus which are excellent in recyclability.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a deflection scanning device according to an embodiment of the present invention.

FIG. 2A is an explanatory diagram of an effect in the deflection scanning device according to the embodiment of the present invention, and FIG. 2B is an explanatory diagram of a shape of a nut driver.

FIG. 3 is a diagram showing a deflection scanning device according to an application example of an embodiment of the present invention.

FIG. 4A to FIG. 4C are diagrams showing a modification of the embodiment of the present invention.

FIG. 5 is a diagram showing a conventional example in Japanese Patent Laid-Open No. 2000-249953.

FIG. 6 is a diagram showing a conventional example.

FIG. 7 is an explanatory diagram of “tilt” and scanning line shift.

FIG. 8 is an explanatory diagram of tilt adjustment in the conventional example shown in FIG.

9 is a detailed explanatory diagram of tilt adjustment in the conventional example shown in FIG.

FIG. 10 is an explanatory diagram of a problem in another conventional example.

[Explanation of symbols]

1,201 optical box 2,202 Light source 4,204 scanner motor 5,205 rotating polygon mirror 6a, 6b, 206a, 206b scanning lens 7,207 Scanned surface. 8,208 scan lines. 10,210 sensor L luminous flux

Continued front page    F-term (reference) 2C362 AA45 AA48 DA02                 2H045 AA01 BA02 DA02 DA04                 5C051 AA02 CA07 DB22 DB30 DE24                 5C072 AA03 DA02 HA02 HA09 HA13                       HB10

Claims (7)

[Claims] 1. A light source unit, a unit for deflecting and scanning a light beam from the light source unit, a scanning image forming unit for irradiating the light beam deflected by the deflection scanning unit as a scanning line on a surface to be scanned, and the light source unit. And an optical box for accommodating the deflection scanning means and the scanning image forming means, the optical box being supported by a supporting portion of the image forming apparatus main body frame, and the optical box being fixed with respect to the supporting portion. And a fixing member for adjusting the positional relationship between the optical box and the support portion, and at least one adjusting member mounting portion provided in the optical box body. A deflection scanning device that is an adjustable fixing unit having a fixing unit that fixes the adjusting member to the adjusting member attaching unit, wherein the reference is set with a direction in which the adjusting member is fixed to the adjusting member attaching unit as a reference axis. The force in the plane substantially orthogonal to the axis is The operation to be applied to the fixing means, the adjusting member is a deflection scanning apparatus characterized by being fixed to the adjusting member mounting portion. 2. The adjustment member mounting portion has a guide groove for guiding the adjustment member, the adjustment member faces the adjustment member mounting portion, and the optical box is supported by the support portion. And adjusting the positional relationship between the optical box and the supporting portion by moving the adjusting member along a surface facing the adjusting member mounting portion according to the guide groove. The deflection scanning device according to claim 1, wherein: 3. The deflection scanning device according to claim 1, wherein the fixing unit is a screwing unit that is screwed through the adjusting member mounting portion. 4. The deflection according to claim 3, wherein the screwing means includes a bolt provided on the adjusting member and extending along the reference axis, and a nut screwed with the bolt. Scanning device. 5. The screwing means includes a screw hole formed in the adjusting member along the reference axis, and a bolt screwed into the screw hole. Deflection scanning device. 6. The fixing means includes a protrusion provided on the adjusting member, the protrusion having a through hole extending in a direction substantially orthogonal to the reference axis, and a wedge-shaped member penetrating the through hole. The deflection scanning device according to claim 1 or 2. 7. An image carrier having a photoconductive layer, a light source section, and means for deflecting and scanning a light beam from the light source section,
An image forming apparatus provided with a scanning image forming means for irradiating the light beam deflected by the deflecting scanning means onto the image carrier as a scanning line, and an optical box for accommodating the light source section, the deflection scanning means and the scanning image forming means. In the above, the frame body of the image forming apparatus main body has a supporting portion that supports the optical box, the optical box has a fixing portion that is fixed to the supporting portion, and among the fixing portions, At least one is an adjustment member that adjusts the positional relationship between the optical box and the support portion, an adjustment member attachment portion that is provided in the optical box body, and a fixing that fixes the adjustment member to the adjustment member attachment portion. An adjustable fixing part having a means, wherein the adjusting member is an operation of applying a force in a plane substantially orthogonal to the reference axis to the fixing means, with the direction in which the adjusting member is fixed to the adjusting member attaching part as a reference axis. , The adjusting member is An image forming apparatus fixed to an adjusting member mounting portion.