JP2000180748A - Division scanner and beam state adjusting method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust a division scanner and to make satisfactory the scanning line position, a beam diameter and a light quantity at the point part on a medium to be scanned. SOLUTION: A semiconductor laser beam source is moved to coarsely adjust the light quantity (100), so that the semiconductor laser beam source and a cylindrical mirror are adjusted to coarsely adjust a subscanning position(102). Thereafter, a beam focus position is adjusted (104), the beam diameter at the joint part is adjusted (106), main scanning and sub scanning positions at the joint part are adjusted (108), and the light quantity at the joint part is adjusted (110).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device for writing an image by scanning a light beam, and more particularly to a divided scanning device for dividing a scanning in a main scanning direction and a beam state adjusting method of the divided scanning device. This is suitable for, for example, digital copiers and laser printers.

[0002]

2. Description of the Related Art Conventionally, as this type of optical scanning device, there is one as shown in FIG. 17, for example. This optical scanning device irradiates a laser beam emitted from one light source 80 to a rotating polygon mirror 84 through a condenser lens group 82, and irradiates the laser beam emitted to the rotating polygon mirror 84 with the rotating polygon mirror. The light is reflected by a reflecting surface 84A that moves with the rotation of 84, so that scanning exposure is performed along the axial direction of the photosensitive drum 88 via an imaging lens 86.

In recent years, it has been desired that image recording apparatuses such as laser printers and digital copying machines output high-resolution images at high speed. To meet this demand, it is necessary to increase the number of scanning lines per unit time, and in an apparatus using a rotating polygon mirror, it is conceivable to increase the number of rotations of a scanner motor for driving the rotating polygon mirror.

However, the rotation speed of the scanner motor for driving the rotary polygon mirror is limited to 15,000 rpm when ball bearings are used. Also,
The limit is 40,000 rpm even if an air bearing that causes a significant cost increase is used. Therefore, there is a limit to achieving higher speed and higher resolution by increasing the number of rotations of the rotating polygon mirror.

[0005] Next, it is conceivable to increase the number of reflecting surfaces of the rotating polygon mirror. However, as the number of reflecting surfaces increases, the diameter of the rotating polygon mirror increases. There is a problem that reliability is reduced due to an increase in load on the motor. Also, as the number of reflecting surfaces increases, the scanning angle at which one reflecting surface scans the laser beam inevitably decreases, so that the scanning width at a position at a fixed distance from the rotary polygon mirror decreases with the decreasing scanning angle. Be shorter. In other words, in order to secure the same scanning width as in the related art, it is necessary to increase the distance from the rotary polygon mirror to the photosensitive drum.
As a result, there is a problem that the size of the optical scanning device is increased.

[0006] In order to solve this problem,
As disclosed in Japanese Patent Application Laid-Open No. H10-177147, there is known a divided scanning device that performs divided scanning on the surface of a medium to be scanned along a main scanning direction. FIGS. 18 and 19 show an embodiment disclosed in this publication. FIG.

In the split scanning system of the split scanning system, laser beams A and B from two semiconductor laser light sources 90a and 90b are made incident on the same reflecting surface of a rotary polygon mirror 92 and reflected by a rotary polygon mirror 92. The medium to be scanned 94 is divided and scanned by two beams, and two light beams are respectively ± α in a main scanning direction with respect to a center line 96 reaching a scanning center position.
Is incident on the rotating polygon mirror 92 at an angle of .alpha., And the total scanning angle of the two light beams deflected while the rotating polygon mirror 92 rotates by the angle .alpha. Is set to. +-. 2.alpha .. This allows
In a simultaneous two-segment optical device that achieves high speed and high resolution, it is possible to achieve both higher miniaturization and higher image quality at a higher level.

[0008] However, in such a divisional scanning type divisional scanning device, the effective scanning width on the medium to be scanned is dividedly scanned by two scanning lines, so that the relative position of each scanning line and the beam diameter at the joint portion of the image. Depending on the difference in light quantity, overlapping or missing images may occur, and a difference in density may occur.

For this reason, it is important to adjust the relative position, beam diameter, and light amount of each scanning line at the joint with high precision. In the conventional divided scanning apparatus of the divided scanning system disclosed in Japanese Patent Application Laid-Open No. H10-177147, specific measures and means for adjusting the relative position, beam diameter, and light amount of each scanning line at the joint are completely described. Not been.

Therefore, a specific means for adjusting the relative position of each scanning line at the joint is disclosed in Japanese Patent Laid-Open No. 10-206.
No. 761. FIG. 20 is a diagram showing an embodiment disclosed in this publication.

Japanese Patent Application Laid-Open No. 10-206761 relates to a technique relating to a division scanning system of a division scanning system employing an overfilled optical system technique. This overfilled optical system technology is a technology for irradiating the reflecting surface of the rotating polygon mirror with a light beam wider than the width of the reflecting surface. The diameter of the rotating polygon mirror is reduced by irradiating a light beam and using the entire reflecting surface.

However, when the overfilled optical system technology is adopted in the divisional scanning method, the light beam reflected by the adjacent surface of the reflecting surface of the rotary polygon mirror simultaneously scans the other scanning region where the divisional scanning is being performed. Exposure occurs.
In order to solve this problem, the reflecting mirrors 98A and 98B that independently reflect the two light beams are arranged so that the adjacent surface light is not guided onto the medium to be scanned.

According to this embodiment, the reflecting mirrors 98A and 98B are provided with a three-axis rotating mechanism in the X and Y directions in FIG. , And the inclination can be adjusted. FIG. 20B shows a configuration in which two reflecting mirrors are provided, respectively.
In this configuration, the three-axis adjustment mechanism is disassembled for each axis to improve the ease of adjustment and the accuracy.

[0014]

However, in the embodiment shown in FIG. 20A of Japanese Patent Application Laid-Open No. 10-206761, although the configuration is simple, if one reflecting mirror is provided with a three-axis adjusting mechanism. If this is the case, the structure becomes complicated, and miniaturization of the device and easiness of adjustment are hindered. FIG.
In the embodiment shown in (b), the following problem occurs, and it is difficult to accurately adjust the scanning line position on the medium to be scanned only by the above configuration.

For example, in the embodiment shown in FIG. 20B, the reflecting mirror 98a moves in the sub-scanning direction (X direction).
It is described that A can be adjusted with high accuracy by moving in the main scanning direction (Y direction) and rotating the reflecting mirror 98B (θ direction). In this case, the reflecting mirror 98b having no adjusting mechanism is usually fixed with a certain error. Therefore, the light beam reflected by the reflecting mirror 98b does not always enter the generatrix of the reflecting mirror 98B. Especially reflecting mirror 98
When a cylindrical mirror is used for B, the conjugate relationship between the reflecting surface of the rotating polygon mirror and the medium to be scanned is broken, and the deviation of the scanning line caused by the variation of the reflecting surface of the rotating polygon mirror, which is the original role of the cylindrical mirror. Cannot be corrected, and density unevenness occurs.

In the above description, no specific measures have been proposed for ensuring image quality by characteristics other than the scanning position of the joint portion, and there is room for improvement in these points.

The present invention has been made to solve the above problems, and can easily adjust a divided scanning device.
It is another object of the present invention to provide a divided scanning device and a beam state adjusting method of the divided scanning device that can improve the scanning line position, the beam diameter, and the light amount at the joint portion on the medium to be scanned.

[0018]

In order to achieve the above object, the present invention provides two light sources for emitting a light beam, and a light source provided for each of the light sources, wherein the light beam emitted from the light source has a predetermined beam shape. A first imaging optical system for forming an image at the first scanning optical system and
And a rotating polyhedron for deflecting two light beams incident from the imaging optical system on the same plane and a reflecting surface narrower than the width of the light beam, and linearly deflecting the two light beams deflected by the rotating polyhedron. A second imaging optical system that forms an image on the rotating polyhedron through the second imaging optical system.
Guiding means for individually guiding the two light beams onto the medium to be scanned and performing divided scanning; scanning position adjusting means for adjusting a scanning position of the two light beams on the medium to be scanned;
Beam diameter adjusting means for adjusting the light beam diameter of the two light beams on the medium to be scanned, and light amount adjusting means for adjusting the light amount of the two light beams on the medium to be scanned; It is characterized by:

According to the structure of the present invention, light beams are respectively emitted from the two light sources, and the light beams emitted from the light sources are converted into the predetermined light beams by the first imaging optical system provided for each of the light sources. Image into a shape. Further, two light beams are incident on the same plane of the rotating polyhedron at different angles in the main scanning direction and the sub-scanning direction. The reflecting surface of the rotating polyhedron that deflects the light beam is a reflecting surface that is narrower than the width of the incident light beam. That is, a light beam having a wider width than the reflecting surface of the rotating polyhedron enters the rotating polyhedron.

In the main scanning direction, a rotating polyhedron is used.
The two light beams are respectively deflected by a predetermined angle, and the respective light beams deflected by the rotating polyhedron through the second imaging optical system by the guiding means are guided onto the medium to be scanned, and one line of the light beam on the medium to be scanned is guided. The scan is divided into scans.

The scanning position adjusting means can adjust the scanning position of the joint of the light beams emitted from the two light sources and scanned on the medium to be scanned, and the two light beams at the joint can be adjusted by the beam diameter adjusting means. The beam diameter of the beam can be adjusted. Further, the two light amounts at the joint can be adjusted by the light amount adjusting means. Therefore, by adjusting each adjusting means, it is possible to easily adjust the divided scanning device, and to improve the scanning position, the beam diameter, and the light amount at the joint of the two light beams on the medium to be scanned. Can be.

Incidentally, the guide means may use an optical member for converging the light beam in the sub-scanning direction, for example, a cylindrical mirror or a cylindrical lens.

Further, the scanning position adjusting means may be constituted by a main scanning position adjusting means for adjusting a main scanning position and a sub-scanning position adjusting means for adjusting a sub-scanning position.

In this case, the main scanning position adjusting means may perform the adjustment by controlling the writing timing of the main scanning position.

Further, the sub-scanning position adjusting means may perform the adjustment by rotating the guide means and controlling the writing timing in the sub-scanning direction.

Further, the sub-scanning position adjusting means may move the guide means in the sub-scanning direction.

The beam diameter adjusting means may comprise a main scanning beam diameter adjusting means for adjusting the beam diameter in the main scanning direction and a sub-scanning beam diameter adjusting means for adjusting the beam diameter in the sub-scanning direction.

In this case, the main scanning beam diameter adjusting means may adjust the main scanning beam diameter by adjusting the focal position of the light beam emitted from the light source.

The sub-scanning beam diameter adjusting means may adjust the tilt by inclining a cylindrical lens constituting the first optical system.

The light amount adjusting means may adjust the light amount by moving at least the light source or changing the light amount of the light source.

According to an eleventh aspect of the present invention, there are provided two light sources for emitting light beams, and a first light source provided for each of the light sources and configured to image the light beams emitted from the light sources into a predetermined beam shape. An image optical system, and a rotating polyhedron that deflects two light beams incident from the image forming optical system at different angles in the main scanning direction and the sub-scanning direction on the same plane and a reflecting surface smaller than the width of the light beam. A second imaging optical system that linearly images the two light beams deflected by the rotating polyhedron, and the two light beams deflected by the rotating polyhedron through the second imaging optical system, respectively. And a guide means for guiding the laser beam onto the medium to be scanned and performing a split scan, wherein the beam state adjusting method of the split scanning device includes: a light amount coarser at a joint portion of each of the light beams emitted from the two light sources. Adjustment And then performing a coarse adjustment of the sub-scanning position at the joint of the two light beams divided and scanned on the medium to be scanned, and then joining the two light beams divided and scanned on the medium to be scanned. After adjusting the focal position in the main scanning direction and the sub-scanning direction in the section, and adjusting the main scanning and sub-scanning positions in the joint portion of the light beam divided and scanned by the guide means, the light amount of the joint portion is adjusted. It is characterized in that adjustment is performed.

According to the structure of the present invention, light beams are respectively emitted from the two light sources, and the light beams emitted from the light sources are converted into the predetermined beam by the first imaging optical system provided for each light source. Image into a shape. Further, two light beams are incident on the same plane of the rotating polyhedron at different angles in the main scanning direction and the sub-scanning direction. The reflecting surface of the rotating polyhedron that deflects the light beam is a reflecting surface that is narrower than the width of the incident light beam. That is, a light beam having a wider width than the reflecting surface of the rotating polyhedron enters the rotating polyhedron.

Further, the rotating polyhedron is used in the main scanning direction.
The two light beams are respectively deflected by a predetermined angle, and the respective light beams deflected by the rotating polyhedron through the second imaging optical system by the guiding means are guided onto the medium to be scanned, and one line of the light beam on the medium to be scanned is guided. A beam state adjusting method of a divisional scanning device for performing spectral scanning, in which coarse adjustment of the amount of light at a joint portion of respective light beams emitted from two light sources is performed, and then the medium to be scanned is dividedly scanned. After the coarse adjustment of the sub-scanning position at the joint of the two light beams is performed, the focal position in the main scanning direction and the sub-scanning direction at the joint of the two light beams divided and scanned on the medium to be scanned is adjusted; After adjusting the main scanning and sub-scanning positions at the joints of the light beams divided and scanned by the guide means, finally, the light amount of the joints is adjusted.

By adjusting the beam state of the divided scanning device according to such a procedure, the adjustment can be easily performed without repeating each adjustment, and the joint in image quality can be set to an acceptable level. That is, this is an optimal adjustment method for adjusting the beam state of the divided scanning device.

For example, a divided scan 2 is performed on the medium to be scanned.
When the focus positions in the main scanning direction and the sub-scanning direction at the joint portion are adjusted after adjusting the light amount at the joint portion of the two light beams, the light amount at the joint portion adjusted earlier in the main scanning direction and the sub-scanning direction. Adjustment of the focus position may cause a shift. In this case, it is necessary to adjust the light amount at the joint again. However, by adjusting the beam state according to the above-described procedure, it is possible to improve the scanning line position, the beam diameter, and the light amount at the joint portion on the medium to be scanned, and to efficiently divide without repeating each adjustment. Beam condition adjustment of the scanning device can be performed.

[0036]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows (a) a plan view and (b) a side view of the configuration of a divided scanning device 10 according to a first embodiment of the present invention. In FIG. 1, two light source units that emit light beams for scanning are arranged at positions symmetrical with respect to a center line CL indicating the center of the scanning range. The two light source units include semiconductor laser light sources 12a and 12b that emit light beams having a substantially Gaussian distribution, respectively. In this embodiment, the light beam emitted from the semiconductor laser light source 12a is referred to as a first light beam LBA,
The light beam emitted from 2b is referred to as a second light beam LBB. Semiconductor laser light sources 12a and 12b in the light source section
The collimator lens 14 has a function of turning the light beam into substantially parallel light when a light beam having a different spread angle in the vertical and horizontal directions is emitted from the focal position.
a, 14b, beam shaping slits 16a, 16b for passing only the central light beam, and cylindrical lenses 18a, 18b for converging the incident light beam in the sub-scanning direction near the deflection surface of a rotary polygon mirror described later, respectively. Are located.

The semiconductor laser light sources 12a, 12b
Is connected to a control unit (not shown), which controls the semiconductor laser light sources 12a and 12a based on the image information.
Control for modulating the light beam output of b is performed.

The collimator lenses 14a, 14b
Is disposed at a position where the distance from the semiconductor laser light sources 12a and 12b is shorter than the focal length of the collimator lenses 14a and 14b by about 1 mm. With this arrangement, the light beam passing through the collimator lenses 14a and 14b is substantially It becomes a loose divergent light instead of a parallel light.

Further, the cylindrical lenses 18a, 1
At the extension of the light beam emission side 8b, plane mirrors 20a and 20b that reflect the emitted light beam are arranged at symmetrical positions with respect to the center line CL. Flat mirror 2
On the reflection side of 0a and 20b, a polygonal prism having a plurality of deflecting surfaces (mirror surfaces) having the same surface width on the side surface is formed, and is rotated around the central axis at a constant angular velocity in a direction indicated by an arrow by driving means (not shown). A rotating polygon mirror 22 (so-called polygon mirror) is provided. The polygon mirror 22 is
It is arranged at a position where the center line CL passes through the center axis.

An fθ lens 24 composed of a pair of lenses is disposed between the plane mirrors 20a and 20b and the polygon mirror 22 so that the optical axis thereof coincides with the center line CL. For an overfilled optical system, f
lens converges in the main scanning direction the first light beam LBA and the second light beam LBB of the gently divergent light reflected by the plane mirrors 20a and 20b as an elongated line image wider than the image width of the polygon mirror 22. Is done. At this time, the first light beam LBA and the second light beam LBB are incident such that their centers reach the same deflection surface of the polygon mirror 22. Thus, the first and second light beams LB
A and LBB converge so as to straddle a plurality of deflection surfaces.

Further, the fθ lens 24 outputs the light beam deflected by the polygon mirror 22 to the fθ lens 24 again.
And a function of converging the light beam that has passed again as a light spot on a photoreceptor 34 to be described later and moving the light spot on the photoreceptor 34 at a substantially constant speed in the main scanning direction. Having.

On the side of the polygon mirror 22 where the fθ lens 24 is disposed, the polygon mirror 22
Cylindrical mirrors 26a and 26b that reflect the light beam for image recording deflected by the mirror are arranged, and are reflected by the cylindrical mirrors 26a and 26b before being irradiated with the light beam on a photosensitive member 34 arranged below. In FIG. 1, the cylindrical mirrors 26a, 26b
However, a flat mirror or a cylindrical lens may be used. The cylindrical mirrors 26a and 26b and the cylindrical lens have a light condensing ability in the sub-scanning direction, and have a function of correcting a displacement in the sub-scanning direction on the photoconductor 34 caused by a variation in the deflection surface of the polygon mirror 22.

The photosensitive member 34 has an elongated cylindrical shape with a photosensitive material responsive to a light beam applied to the surface thereof, and the main scanning direction coincides with the longitudinal direction of the photosensitive member 34. Are located. That is, the light spot converged on the photoreceptor 34 together with the rotation direction of the polygon mirror 22 moves along the main scanning direction, and the image can be recorded on the scanning line.

The photosensitive member 34 is rotated at a constant rotational speed about a rotation axis thereof by a driving means (not shown), and the scanning lines on the photosensitive member 34 are sequentially moved in the sub-scanning direction. Done. The deflection corresponding to the image recording of one scanning line by the polygon mirror 22 is performed by one deflection surface.

Further, in order to set a write start position at which image recording is performed on these lines, a plane mirror that folds the first light beam LBA is provided on the path of the first light beam LBA that has passed through the fθ lens 24. 28, a cylindrical lens 30 for imaging a beam in the sub-scanning direction,
An SOS sensor 32 is provided. The SOS sensor 32 is connected to a control unit (not shown), and the control unit starts modulating the image signal after a predetermined time has elapsed from the time when the output signal of the SOS sensor 32 is detected. Further, the second light beam LBB is synchronized with the output signal of the SOS sensor 32 of the first light beam LBA, and when a predetermined time has elapsed, the modulation of the image signal is started and the division scanning is performed.

Next, the adjustment mechanism of each part of the optical system in the divided scanning device according to the present embodiment will be described.

Semiconductor laser light sources 12a and 12 as light sources
b, as shown in FIG. 2, is arranged on the laser drive circuit board 42 and is configured to be movable in a plane perpendicular to the optical axis, and the semiconductor laser light source is moved in the main scanning direction and the sub-scanning direction. The movement can be adjusted. FIG. 2 shows the semiconductor laser light source 14a, shows the configuration of the optical path of the first light beam LBA emitted from the semiconductor laser light source 14a, and shows the optical path of the second light beam LBB emitted from the semiconductor laser light source 14b. Of the first light beam L
It is omitted because it is the same as BA.

As described above, the semiconductor laser light sources 12a and 12a
By enabling the movement adjustment of b, the light amount distribution can be adjusted.

The collimator lenses 14a and 14b are disposed in the lens barrel 44, and the lens barrel 44 is provided with a regulating member 4 provided on a housing 40 forming an outer frame of the split scanning device.
8, the lens barrel 44 is arranged so as to be movable only in the optical axis direction, and the movement of the lens barrel 44 is restricted by the urging force of the elastic member 50.

The lens barrel 44 is moved, and the semiconductor laser light source 1 is moved.
By adjusting the distance between the photoconductor 3 and the photoconductor 3
The focus position of the light beam in the main scanning direction, which forms an image on the light source 4, can be adjusted. The collimator lenses 14a, 14
Even if b is fixed and the semiconductor laser light source is moved in the optical axis direction, the focus position of the light beam in the main scanning direction that forms an image on the photosensitive member 34 can be similarly adjusted. In this case, the collimator lenses 14a and 14b are fixed by the housing 40 and the lens barrel 4.
4 may be fixed with an adhesive or the like.

The cylindrical lenses 18a and 18b are
As shown in FIG. 2, similarly to the collimator lenses 14a and 14b, the
Numeral 6 is disposed in a V-shaped groove provided in the housing 40 so as to be movable in the optical axis direction and rotatable with respect to the center (general line) of the cylindrical lens. Fixed by power. As described above, the cylindrical lenses 18a and 18b are configured to be able to move in the optical axis direction and rotate around the optical axis, that is, TILT.

The cylindrical mirrors 26a and 26b are
It has a rotation mechanism as shown in FIG. FIG. 3 is a diagram showing a rotation mechanism of the cylindrical mirror 26a.
The description of the cylindrical mirror 26b is omitted because it is the same.

The cylindrical mirrors 26a and 26b are
Holding members 55 for holding the cylindrical mirrors 26a, 26b at both ends of the cylindrical mirrors 26a, 26b
Are provided, and the rotating shaft 5 fixed to the holding member 55 is provided.
2 is rotatably supported by a support member 54 provided in the housing 40. In addition, the cylindrical mirror 2
The reflecting surfaces of 6a and 26b and the rotation center of the rotating shaft 52 are configured to coincide.

Further, the cylindrical mirrors 26a, 26
On the light beam incident side b, an L-shaped member 56 is screwed to the housing 40 with a screw, and a screw 58 for adjusting the rotation of the cylindrical mirrors 26a and 26b passes through the L-shaped member 56. The cylindrical mirrors 26a and 26b are configured to rotate when the screw 58 is rotated. Further, an elastic member 60 is screwed to the housing 40 with a screw on the surface of the cylindrical mirrors 26a and 26b opposite to the light beam incident side facing the screw 58, and the cylindrical member is biased by the elastic member 60. The rotation of the mirrors 26a and 26b is suppressed.

With this configuration, the sub-scanning position of the joint on the photosensitive member 34 can be adjusted to the absolute position by rotating the cylindrical mirrors 26a and 26b. Further, the rotation mechanism may be only the cylindrical mirror 26b (or 26a) on one side,
In this case, the fixed-side first light beam LBA (or the second
The movable side light beam second light beam LBB (or first light beam LBA) is located at the sub-scanning position of the light beam LBB).
Is a relative position adjustment.

Further, the cylindrical mirrors 26a, 26
The rotation mechanism of FIG. 3B is not limited to this, and FIG.
May be used.

The rotation mechanism shown in FIG. 3B includes a holding member 62 for holding the cylindrical mirror 26a and a holding member 6 for holding the cylindrical mirror 26a.
2 and a support member 64 for supporting the second member 2. The holding member 62 has a shape obtained by cutting off a part of a cylinder, and is configured such that the mirror rotation center coincides with the center of the cylinder.
The holding member 62 is fitted and supported in a semicircular hole of the support member 64. The rotation of the cylindrical mirror 26a is restricted by turning a screw 66 passing through the support member 64. As described above, the holding member 62 rotates without shifting the rotation center of the mirror in the semicircular hole, and can change the inclination angle of the cylindrical mirror 26a to change the angle of the reflected light.

Although the above-described rotating mechanism of the cylindrical mirror 26b (or 26a) can make the sub-scanning position of the two light beams be accurate to one line or less, the sub-scanning is electrically performed in consideration of workability and the like. By controlling the light beam writing timing in the direction, the sub-scanning position can be adjusted with higher accuracy.

In this embodiment, the light beam writing timing is controlled in order to finely adjust the beam joint in the sub-scanning direction. The control of the light beam writing timing is such that the sub-scanning position can be delayed by a plurality of lines for each line, and the sub-scanning position can be adjusted by rotating the cylindrical mirrors 26a and 26b within the delayable range. Become. For example, it can be realized by the method disclosed in Japanese Patent Application Laid-Open No. 10-232357. The range in which the delay is possible can be arbitrarily set according to the number and capacity of the memories. In addition, the control of the light beam writing timing may be performed by only one side of the light beam. In this case, the relative position of the movable side light beam to the fixed side light beam sub-scanning position may be adjusted.

The adjustment of the main scanning position at the joint is as follows.
This is performed by controlling the light beam writing timing similarly to the sub-scanning direction. In the control of the write start timing, the write start position can be adjusted in units of one dot based on the synchronization signal from the SOS sensor 32. For example, it can be realized by the method disclosed in Japanese Patent Application Laid-Open No. 10-232357. Usually, a certain degree of tolerance (error) occurs in component accuracy and assembly accuracy. For example, the second
If the angle of incidence of the light beam LBB on the polygon mirror 22 shifts or is adjusted, a phenomenon such as overlapping or missing images occurs at the joints on the photoconductor. By controlling the write start timing described above, it is possible to accurately connect images at the joint in the main scanning direction.

Next, the main scanning and sub-scanning position adjustment at the joint, the beam diameter at the joint, and the light quantity adjustment at the joint performed by the above-described adjustment mechanism will be described.

For example, as shown in FIG. 4, a dot where the first light beam LBA finally enters one main scanning line
The dot (the rear end dot) and the dot (the front end dot) where the second light beam LBB first enters one scanning line are shifted by 2 dots in the main scanning direction and 3 lines in the sub-scanning direction (FIG. 4A ) Condition).

First, the position shift in the main scanning direction is adjusted by controlling the writing start timing described above for the position shift in the main scanning direction. In this case, the first light beam LBA
Is started by writing the second light beam LBB two dots earlier by delaying the second light beam by 2 dots, so that the shift 2dot in the main scanning direction can be adjusted (the state of FIG. 4B). Similarly, the positional deviation in the sub-scanning direction is adjusted by controlling the above-described writing start timing. In this case, the shift of the three lines in the sub-scanning direction can be adjusted by starting writing with the first light beam LBA delayed by three lines or starting writing the second light beam LBB three lines earlier (FIG. 4). (State of (c)).

The beam diameter at the joint adjusts the focal position and the spot size. First, the focal position is provided with separate mechanisms for the beam diameter (Tangential) in the main scanning direction and the beam diameter (Sagital) in the sub-scanning direction. The main scanning direction is determined by the semiconductor laser light sources 12a and 12b and the collimator lens 14a. This is performed by changing the interval of 14b. The beam focal position in the sub-scanning direction is performed by moving the cylindrical lenses 18a and 18b in the optical axis direction. The spot size is the cylindrical lens 18a,
The rotation in the main scanning direction and the sub-scanning direction can be adjusted by the rotation of the 18b (TILT mechanism).

FIG. 5A shows a beam in the main scanning direction.
(B) shows the change of the beam in the sub-scanning direction. In the figure, the horizontal axis indicates the scanning position, and the vertical axis indicates the beam diameter, and shows the change in the beam diameter in the scanning area according to the rotation angle of the cylindrical lenses 18a and 18b. The scanning position on the horizontal axis is 0 m
The position of m corresponds to a joint where the two light beams LBA and LBB are connected.

As shown in FIG. 5, the joint angle and the uniformity of the beam diameter in the scanning area are adjusted by the rotation angles of the cylindrical lenses 18a and 18b.

The amount of light at the joint is determined in two stages: coarse adjustment and fine adjustment. First, the rough adjustment is performed by the semiconductor laser light source 12.
This is performed by moving a and 12b in the main scanning direction in a plane perpendicular to the optical axis. The present invention employs an overfilled optical system, detects the light amount balance of the scanning end after deflection by the polygon mirror 22, and determines the position in the main scanning direction. As shown in FIG. 6, the scanning end in the divided scanning method is as follows for the first light beam LBA and for the second light beam LBB. Ideally, the balance between this and the other is balanced and the light amounts of the first and the second are equal (FIG. 6A). However, it is possible to achieve both the balance and the light amount difference, but the man-hour required for the adjustment increases. FIG. 6 (b) shows that the adjustment is performed with emphasis on balance.
However, since the difference in the light amount at the joint is important in the divided scanning method and the sensitivity to the image quality is high, adjustment is made so that the difference in the light amount is within an allowable range (FIG. 6C). Thereafter, fine adjustment of the light amount is performed by changing the output of the semiconductor laser light sources 12a and 12b according to the light amount on the photoreceptor 34 or the density in image quality.

Next, an adjusting method and an operation of the optical system according to the first embodiment of the present invention will be described with reference to FIGS.

FIG. 7 is a flowchart showing the flow of the adjustment of the above-mentioned optical system. First, in step 100, the semiconductor laser light sources 12a and 12b are moved in the main scanning direction to roughly adjust the light amount.
By adjusting the semiconductor laser light sources 14a and 14b and the cylindrical mirrors 26a and 26b, the respective light beams LBA and LBB emitted from the two semiconductor laser light sources 12a and 12b and irradiated onto the photoconductor 34 are adjusted.
Coarse adjustment of the sub-scanning position of the semiconductor laser light source 12
The optical path from a, 12b to the photoreceptor 34 is established. In the subsequent steps, the beam diameter, light intensity,
Fine adjustment of the scanning position in the main scanning and sub-scanning directions is performed.

Regarding the fine adjustment, after the focal position of the beam is adjusted in step 104, the beam diameter of the joint is adjusted in step 106, and the scanning position of the joint in the main scanning and sub-scanning directions is adjusted in step 108. The adjustment is performed, and in step 110, the light amount at the joint portion is adjusted.

Next, each of the above-described steps 100 to 110 will be described with reference to flowcharts shown in FIGS.

FIG. 8 is a flowchart showing the flow of the coarse adjustment of the light amount in step 100 described above. In the coarse adjustment of the light amount, the first light beam LBA and the second light beam LB
Adjust separately at B. First, in step 120, the first
Of the light beam LBA. In the following step 122, the light amount is detected by an optical sensor arranged at an arbitrary position after the light beam is reflected by the polygon mirror 22,
The detected peak value is held by a peak hold circuit. An optical sensor for detecting the amount of light and a peak hold circuit are provided in a jig for adjusting the divided scanning device 10. The optical sensor is located on a scanning start side (hereinafter, SOS) on an optical path after being deflected by the polygon mirror 22. And the scanning end side (hereinafter referred to as EOS) and the scanning center (hereinafter referred to as COS). The first light beam detects the output detected by the SOS sensor and the COS sensor, and the second light beam detects the output detected by the COS sensor and the EOS sensor. Is used.

In the following step 124, the held peak values of SOS and COS are compared, and the first light beam LB
It is determined whether the peak values at both ends of A are balanced. If it is determined in step 124 that the peak values at both ends are balanced, it is considered that the light amount balance of the first light beam LBA is accurately balanced, and the process proceeds to the next step 128.

If it is determined in step 124 that the peak values at both ends are not balanced, it is assumed that the light source position is deviated, and the process proceeds to step 126 to move and adjust the semiconductor laser light source 12a. The process proceeds to step 122, and the same processing is repeated until the peak values at both ends are balanced.

On the other hand, if it is determined in step 124 that the peak values at both ends are balanced, step 12
The scanning of the second light beam LBB is performed by 8, and the process proceeds to step 130. In step 130, COS and E
The OS is peak-held, and it is determined in step 132 whether both ends are balanced. Step 132
When it is determined that the peak values at both ends are balanced, the process proceeds to step 136. When it is determined at step 132 that both ends are not balanced,
Move to step 134.

In step 134, it is assumed that the light source position is deviated, and the semiconductor laser light source 12b is moved and adjusted. The process proceeds to step 130 and the same processing is repeated until the peak values at both ends are balanced.

Next, at step 136, the peak value of the COS of the first light beam LBA detected at step 122 described above and the second light beam LBB detected at step 128
Are compared, and when it is determined that the peak values are equal, it is assumed that the light amount at the COS is sufficient, and the processing is terminated. If it is determined that the peak values are not equal,
In step 138, the semiconductor laser light source 12b is moved and adjusted, and the process returns to step 136, and the same processing is repeated until the peak values of COS become equal. In this case, it is conceivable that the peak values at both ends of the second light beam LBB may not be balanced. However, with such adjustment, the light quantity distribution in the scanning region is within the image quality allowable level, and there is no practical problem.

FIG. 9 is a flowchart showing a flow of the coarse adjustment of the sub-scanning position in the above-described step 102. In the sub-scan coarse adjustment, first, in step 140, the first
The sub-scanning position detection sensor 36a which detects the sub-scanning position of the first light beam LBA provided at a position equivalent to the photosensitive member on the adjustment jig of the divided scanning device 10 in step 142. Then, the first light beam LBA to be sub-scanned is detected, and the process proceeds to step 144.
In step 144, the sub-scanning position of the first light beam LBA is calculated by the arithmetic circuit of the adjustment jig for the divided scanning device 10 based on the signal of the sub-scanning position detection sensor 36a. Subsequently, the flow shifts to step 146 to scan the second light beam LBB, and then shifts to step 148. Step 14
At 8, the second light beam that is sub-scanned by the sub-scanning position detection sensor 36b that detects the sub-scanning position of the second light beam LBB provided at a position equivalent to the photoconductor on the adjustment jig of the divided scanning device 10 The LBB is detected, and the process proceeds to step 150. In step 150, the sub-scanning position of the second light beam LBB is calculated by the arithmetic circuit of the adjustment jig for the divided scanning device 10 based on the signal of the sub-scanning position detection sensor 36b.

Subsequently, at step 152, the light beam L
It is determined whether the relative position of BA and the light beam LBB in the sub-scanning direction is within an allowable range. Step 152
If it is determined that the value falls within the allowable range, the coarse adjustment of the sub-scanning position ends. If it is determined in step 152 that the value is not within the allowable range, step 1
Then, the flow proceeds to 54, where the rotation of the cylindrical mirror 26b on the second light beam LBB side is adjusted, and the flow returns to step 148.
In step 152, the same processing is repeated until the relative position of the first light beam LBA and the second light beam LBB in the sub-scanning direction falls within the allowable range.

Next, FIG. 10 is a flowchart showing the flow of the beam focus position adjustment in the above-mentioned step 104 and the joint beam diameter adjustment in the above-mentioned step 106.

The beam focal position is adjusted by adjusting the first light beam L
Since the same processing is performed for both the BA and the second light beam LBB, the first light beam LBA will be described as an example. First, in step 160, the first light beam LBA is turned on, and in step 162, the light beam focal position in the main scanning direction is detected.
Subsequently, the light beam focal position in the main scanning direction is calculated from the signal detected in step 164, and the process proceeds to step 166. In step 166, it is determined whether or not the detected focal position is within the allowable range. Step 166
If it is determined that the focal position is within the allowable range, the process proceeds to the next step 170. If it is determined that the collimator lens 14a is not within the allowable range, the process proceeds to step 168. In step 168, the collimator lens 14a is moved and adjusted in the optical axis direction, and then returns to step 162. The same processing is repeated until it enters.

On the other hand, at 166, it is determined that the value falls within the allowable range, and the routine goes to step 170.
In the case of 0, the beam focal position in the sub-scanning direction is detected, the light beam focal position of the sub-scanning position is calculated from the signal detected in step 172, and the process proceeds to step 174. In step 174, it is determined whether or not the detected focal position is within the allowable range. If it is determined in step 174 that the focal position is within the allowable range, the process proceeds to the next step 178. If it is determined that the position is not within the allowable range, the movement of the cylindrical lens 18a in the optical axis direction is adjusted in step 176, and then the flow proceeds to step 1
Returning to step 70, the same processing is repeated until it is within the allowable range in step 174.

Further, in step 174, it is determined that it is within the allowable range, and in step 178, in step 178, the main scanning and the sub-scanning of the joint portion of the first light beam LBA and the second light beam LBB are performed. The beam diameter in the scanning direction is detected. Subsequently, the process proceeds to step 180, where it is determined whether the beam diameter is within the allowable range. If it is determined in step 180 that the beam diameter is within the allowable range, the adjustment of the beam diameter ends. If it is determined in step 180 that the beam diameter does not fall within the allowable range, the process proceeds to step 182, in which the rotation of the cylindrical lens 18a is adjusted (adjustment by the TILT mechanism). The same processing is repeated until it enters.

Next, FIG. 11 is a flow chart showing the main scanning and sub-scanning positions of the joint portion at the above-mentioned step 108 and the flow of adjustment of the light quantity at the joint portion at the above-mentioned step 110. First, step 190
A print sample is collected in step 192. In step 192, the current positional deviation in the main scanning direction is detected from the print sample.
In step 194, the current position shift in the sub-scanning direction is detected from the print sample. Subsequently, in step 196, the current density difference at the joint portion is detected from the print sample,
Move to step 198. In step 198, it is determined whether or not the positional deviation amount in the main scanning direction is within the allowable range. If it is determined in step 198 that the positional deviation is within the allowable range, the process proceeds to the next step 202. Step 1
If it is determined in step 98 that the position does not fall within the allowable range, the process proceeds to step 200. In step 200, the writing timing in the main scanning direction is controlled to adjust the positional deviation in the main scanning direction. Returning to 190, the same processing is repeated in step 198 until the displacement in the main scanning direction falls within the allowable range.

At step 198, it is determined that the value falls within the allowable range.
In 02, it is determined whether or not the shift amount in the sub-scanning direction falls within the allowable range, similarly to the shift amount in the main scanning direction. If it is determined in Step 202 that the value falls within the allowable range, the process proceeds to the next Step 206. Step 20
If it is determined that the value is not within the allowable range in 2,
The process proceeds to step 204, where the writing start timing in the sub-scanning direction is controlled to adjust the position shift in the sub-scanning direction. Then, the process returns to step 190 until the position shift in the sub-scanning direction falls within the allowable range in step 202. The same processing is repeated.

At step 202, it is determined that the value falls within the allowable range.
At 06, it is determined whether or not the density difference at the joint is within the allowable range.

If it is determined in step 206 that the value is not within the allowable range, the process proceeds to step 208,
After the density difference is adjusted by changing the light amounts of the first and second light beams, the process returns to step 190, and the same processing is repeated until the difference falls within the allowable range in step 206. If it is determined in step 206 that the value falls within the allowable range, the series of adjustments are all completed.

According to the above-described procedure, adjustment can be performed efficiently without repeating individual adjustments.

As described above, according to the first embodiment of the present invention, the position of the joint in the main scanning direction, the position in the sub-scanning direction, the beam diameter, and the amount of light can be easily adjusted with high accuracy.

Next, FIG. 12 shows (a) a plan view and (b) a side view of the configuration of a divided scanning device according to a second embodiment of the present invention. The difference between the split scanning device according to the present embodiment and the split scanning device according to the first embodiment in configuration is that the first light beam LBA and the second light beam LBB in FIG. After being deflected and passing through the fθ lens 24, the return reflecting mirror 70
This is the point of the arrangement.

The return reflecting mirror 70 reflects the two light beams reflected by the polygon mirror 22 on a single sheet, and passes the photosensitive member 3 through the cylindrical mirrors 26a and 26b.
4 is being scanned. In the overfilled optical system, the scanning angle of the rotary polygon mirror is smaller than that of the conventional underfilled optical system, so that the optical path length is increased to secure a scanning area. By using the return reflection mirror 70, the optical path is turned back and the size of the device can be reduced. However, when the light beam incident on the return reflecting mirror 70 enters the sub-scanning direction at an angle different from the ideal or at a position different from the ideal, the first light reflected on the return reflecting mirror 70 is returned.
Light beam LBA and the second light beam LBB are incident on positions different from the rotation axes of the cylindrical mirrors 26a and 26b. As long as the light enters the optically effective range of the cylindrical mirrors 26a and 26b, the sub-scanning position on the photoconductor 34 can be adjusted by the rotation of the cylindrical mirrors 26a and 26b. However, the first
Since the positions of the light beam LBA and the second light beam LBB are different from the rotation axes of the cylindrical mirrors 26a and 26b, the rotation of the mirrors shifts the reflection point in the optical axis direction and changes the optical path length. Mirror 26
Correction of scanning line unevenness caused by variation of the deflection surface of the polygon mirror 22, which is an original function of the a and 26b, does not work sufficiently. Further, as in the first embodiment, the cylindrical mirrors 26a and 26b may be flat mirrors or cylindrical lenses.

In order to solve the above-mentioned problems, the first light beam LBA and the second light beam LB are placed at the rotation center, which is the generatrix position of the surfaces of the cylindrical mirrors 26a and 26B.
In order to make B incident, a cylindrical mirror 26a,
A moving mechanism for moving 26b is provided. FIG. 13 shows a mechanism for moving the cylindrical mirrors 26a and 26b.

FIG. 13 shows a configuration of a moving mechanism including a rotating mechanism of the cylindrical mirrors 26a and 26b shown in FIG. 3B. The configuration differs from FIG. 3B in that a moving support member for supporting the support member 64 is provided. The movable support member 72 is fixed to the housing 40, and is configured to movably support the support member 64 in a direction perpendicular to a plane including the optical axis and the rotation center of the cylindrical mirror 26b.

The above-described cylindrical mirror 26
a and 26b are moved by two light beams LBA and LBB.
Although they may be provided for both (cylindrical mirrors 26a and 26b), only one of them can function sufficiently. Therefore, the second embodiment of the present invention employs the second light beam LB
A configuration is provided for the B side (cylindrical mirror 26b). First, the turning reflection mirror 70 is rotated so that the first light beam LBA (or the second light beam LBB) is incident on the rotation center of the fixed-side cylindrical mirror 26a (or 26b). The movable side is the second light beam L
The shift amount of the BB (or the first light beam LBA) from the ideal position in the sub-scanning direction is detected, and based on the shift amount, the cylindrical mirror 26b (or the cylindrical mirror 26).
a) is calculated, and the second light beam LBB (or the first light beam LBA) is added to the cylindrical mirror 26b.
(Or the center of rotation of the cylindrical mirror 26a). The moving direction may be either the normal direction of the cylindrical mirror surface or the direction perpendicular to the ideal incident optical axis.

In order to calculate the amount of movement of the above-mentioned cylindrical mirror 26b, the displacement jig in the sub-scanning direction is detected on the light beam incident side of the cylindrical mirrors 26a and 26b. PSD
Sensors (position sensors) 74a and 74b are provided, respectively.

Next, a description will be given of a method of adjusting the divided scanning device 10 according to the second embodiment of the present invention. The adjustment items are the same as in the first embodiment (see FIG. 7). First, coarse adjustment of the light quantity (step 100) and coarse adjustment of the sub-scanning position (step 102) are performed in this order, and an optical path from the semiconductor laser light source to the photoconductor is established. After establishing the optical path, the beam focal position (step 104), the beam diameter at the joint (step 106), the main / sub scanning position (step 10)
8) Adjust the amount of light (step 110). Here, only the coarse adjustment of the sub-scanning position different from that of the first embodiment of the present invention will be described in detail. The adjustment routine for the coarse adjustment of the sub-scanning position will be described with reference to the flowchart of FIG. This flowchart is for a configuration in which the moving mechanism and the rotating mechanism of the cylindrical mirror are provided only on the second light beam LBB side.

In the coarse adjustment of the sub-scanning position, first, in step 3
In step 00, the first light beam LBA is scanned.
In step 02, the optical path is detected from the output of the PSD sensor 74a provided on the light beam incident side of the cylindrical mirror 26a. In step 304,
It is determined whether or not the optical path detected by the PSD 74a is within the allowable range. If it is determined in step 304 that it is within the allowable range, the process proceeds to step 308. If it is determined in step 304 that it is not within the allowable range, the process proceeds to step 306 and step 3
In step 06, the turning reflection mirror 70 is rotated and adjusted, and the flow returns to step 302 to repeat the same processing until the reflection mirror 70 is within the allowable range.

At step 304, it is determined that the value falls within the allowable range.
In step 08, the second light beam LBB is scanned, and in step 310, the optical path is detected from the output of the PSD sensor 74 b provided on the light beam incident side of the cylindrical mirror 26 b, and the process proceeds to step 312. In step 312, the amount of deviation from the ideal optical path is calculated by an arithmetic circuit (not shown), and the process proceeds to step 314. Step 314
Then, it is determined whether or not the calculated shift amount falls within an allowable range. If it is determined in step 314 that the value falls within the allowable range, the process proceeds to step 320. If it is determined in step 314 that the light beam does not fall within the allowable range, the process proceeds to step 316, and the cylindrical mirror 2 is moved from the displacement amount calculated in step 312 so that the light beam enters the center of the cylindrical mirror 26b.
6b is calculated. Subsequently, the moving mechanism of the cylindrical mirror 26b is adjusted based on the moving amount of the cylindrical mirror 26b calculated in step 318, and the process proceeds to step 320.

Next, the cylindrical mirror is rotated to adjust the sub-scanning position on the photosensitive member. First, step 3
In step 20, the first light beam LBA is scanned, and in step 322, a sub-scanning position is detected by a sub-scanning position detection sensor 36a provided at a position equivalent to the photoconductor on the adjusting jig of the spectral scanning device 10, and At 324, the sub-scanning position is calculated by the arithmetic circuit of the adjustment tool for the divided scanning device 10 based on the detected signal, and the process proceeds to step 326. In step 326, the second light beam LBB is scanned, and in step 328, the sub-scanning position detection sensor 36b provided at a position equivalent to the photosensitive member on the adjusting jig of the spectral scanning device 10
Then, the sub-scanning position is calculated by the arithmetic circuit of the adjusting jig of the spectral scanning device 10 based on the signal detected in step 330 based on the signal detected in step 330, and the process proceeds to step 332. In step 332, the first light beam LBA and the second
It is determined whether or not the relative position of the light beam LBB is within the allowable range. If it is determined in step 322 that the value falls within the allowable range, the adjustment of the sub-scanning position ends. If it is determined in step 322 that the value is not within the allowable range, the process proceeds to step 334, and
At 34, the rotation of the cylindrical mirror 26b is adjusted, and the process returns to step 328, and the same processing is repeated until it is determined at step 332 that it is within the allowable range.

By performing the adjustment according to the above-described procedure, the adjustment can be performed efficiently without repeating each adjustment.

As described above, according to the second embodiment of the present invention, the position of the joint in the main scanning direction, the position in the sub-scanning direction, the beam diameter, and the light amount can be accurately adjusted.
In addition, the size of the device can be reduced.

Next, FIG. 15 shows (a) a plan view and (b) a side view of the configuration of a divided scanning device according to a third embodiment of the present invention. The configuration of the split scanning device according to the present embodiment differs from the split scanning devices according to the first and second embodiments in that the light beams LBA and LBB are deflected by the polygon mirror 22 in FIG. The reflection mirrors 70a and 70b are arranged one by one corresponding to each light beam after passing through the mirror.

The return reflecting mirrors 70a and 70b individually reflect the light beams LBA and LBB and scan the photosensitive member 34 via the cylindrical mirrors 26a and 26b. With this configuration, the size of the divided scanning device can be reduced. However, the return reflecting mirrors 70a and 70b
Will increase. However, unlike the second embodiment of the present invention, no problem occurs due to the angle and position of the light beam incident on the return reflecting mirror 70 in the sub-scanning direction. By arranging the return reflecting mirrors 70a and 70b individually for the two light beams LBA and LBB, each can be adjusted with respect to the rotation center of the cylindrical mirrors 26a and 26b.
A mechanism for moving 6b is not required.

Next, a description will be given of an adjustment method of the divided scanning device 10 according to the third embodiment of the present invention. The adjustment items are the same as in the first embodiment (see FIG. 7). First, coarse adjustment of the light quantity (step 100) and coarse adjustment of the sub-scanning position (step 102) are performed in this order, and an optical path from the semiconductor laser light source to the photoconductor is established. After establishing the optical path, the beam focal position (step 104), the beam diameter at the joint (step 106), the main / sub scanning position (step 10)
8) Adjust the amount of light (step 110). Here, only the coarse adjustment of the sub-scanning position different from that of the first embodiment of the present invention will be described in detail. The adjustment routine for the coarse adjustment of the sub-scanning position will be described with reference to the flowchart in FIG. This flowchart describes a configuration in which the rotation mechanism of the cylindrical mirror is provided only on the second light beam LBB side.

In the coarse adjustment of the sub-scanning position, first, in step 3
At 40, the first light beam is scanned. At the next step 342, the optical path is detected from the output of the PSD sensor 74a of the adjustment jig for the divisional scanning device 10 provided in front of the cylindrical mirror 26a. It is determined whether it is within the allowable range. If it is determined in step 344 that the value is within the allowable range, the process proceeds to step 348. If it is determined in step 344 that the value is not within the allowable range, the process proceeds to step 346. In step 346, the turning reflection mirror 70a is rotated and adjusted, and the process returns to step 342, and the same processing is repeated until it is determined in step 344 that the mirror is within the allowable range.

On the other hand, in step 348, the second light beam LBB is scanned, and in the following step 350, the optical path is detected from the output of the PSD sensor 74b of the adjustment jig for the divided scanning device 10 provided in front of the cylindrical mirror 26b. ,
It is determined whether the value detected in step 352 is within the allowable range. If it is determined in step 352 that the value is within the allowable range, the process proceeds to step 356. If it is determined in step 352 that the value is not within the allowable range, the process proceeds to step 354. Step 354
Then, the turning reflection mirror 70b is rotationally adjusted, the process returns to step 350, and the same processing is repeated until it is determined in step 352 that the mirror is within the allowable range.

Next, the cylindrical mirror is rotated to adjust the sub-scanning position on the photosensitive member. First, step 3
In step 56, the first light beam LBA is scanned, and
At 58, the output of the sub-scanning position detection sensor 36a provided at a position equivalent to the photoconductor on the adjustment tool of the divided scanning device 10 is detected, and the arithmetic circuit of the adjustment device of the divided scanning device 10 adjusts the value output at step 360. Calculate the sub-scanning position,
Move to step 362. In step 362, the second
In step 364, the output of the sub-scanning position detection sensor 36b provided at a position equivalent to the photosensitive member on the adjusting jig of the divided scanning device 10 is detected, and from the value output in step 366, Step 3: Calculate the sub-scanning position by the arithmetic circuit of the divisional scanning device 10 adjustment jig
Go to 68. In step 368, the sub-scanning positions of the first and second light beams are compared to determine whether the relative position is within an allowable range. If it is determined in step 368 that the value falls within the allowable range, the adjustment of the sub-scanning position ends. If it is determined in step 368 that the value is not within the allowable range, the process proceeds to step 370, in which the rotation of the cylindrical mirror 26b on the second light beam LBB side is adjusted, and the process returns to step 364. The same processing is repeated until it is determined that the data is included.

By performing the adjustment in the above-described procedure, the adjustment can be performed efficiently without repeating the individual adjustment.

As described above, according to the third embodiment of the present invention, a highly accurate divided scanning device having a simpler configuration can be obtained.

[0111]

As described above, according to the present invention,
A divided scanning device that divides a scan includes a scanning position adjusting unit that adjusts a scanning position on a medium to be scanned, a beam diameter adjusting unit that adjusts a light beam diameter, and a light amount adjusting unit that adjusts a light amount. This has an excellent effect that the division scanning device can be easily adjusted, and the scanning line position, the beam diameter, and the light amount at the joint on the medium to be scanned can be improved.

Further, according to the present invention, at the joint portion of the light beams emitted from the two light sources of the divided scanning device, the coarse adjustment of the light amount, the coarse adjustment of the sub-scanning position, and the focal position adjustment in the main scanning direction and the sub-scanning direction. By adjusting the divided scanning device in the order of main scanning and sub-scanning position adjustment and light amount adjustment, the adjustment can be performed efficiently without repeating the individual adjustments.

[Brief description of the drawings]

FIG. 1A is a plan view and FIG. 1B is a side view showing a configuration of a divided scanning device according to a first embodiment of the present invention.

2A is a side view, FIG. 2B is a cross-sectional view taken along line AA, and FIG. 2C is a cross-sectional view taken along line BB, showing a configuration of the light source unit according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of a mirror rotation mechanism according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining misregistration correction in a main scanning direction and a sub-scanning direction.

FIG. 5 shows a change in spot size due to rotation of a cylindrical lens (TILT mechanism).

FIG. 6 is an explanatory diagram of light amount adjustment according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating a flow of adjustment of the divided scanning device according to the first embodiment of the present invention.

FIG. 8 is a flowchart illustrating a flow of coarse adjustment of the light amount.

FIG. 9 is a flowchart illustrating a flow of coarse adjustment of a sub-scanning position.

FIG. 10 is a diagram illustrating a flow of beam focus position adjustment and beam diameter adjustment at a joint portion.

FIG. 11 is a diagram showing a main / sub scanning position of a joint portion and a flow of light amount adjustment.

FIGS. 12A and 12B are a plan view and a side view showing a configuration of a divided scanning device according to a second embodiment of the present invention; FIGS.

FIG. 13 is a configuration diagram of a mirror moving mechanism according to the embodiment of the present invention.

FIG. 14 is a flowchart illustrating a flow of coarse adjustment of a sub-scanning position of the divided scanning device according to the second embodiment of the present invention.

FIGS. 15A and 15B are a plan view and a side view showing a configuration of a divided scanning device according to a third embodiment of the present invention. FIGS.

FIG. 16 is a flowchart illustrating a flow of coarse adjustment of a sub-scanning position of the divided scanning device according to the third embodiment of the present invention.

FIG. 17 is a schematic diagram illustrating a configuration of a conventional optical scanning device.

FIG. 18 is a configuration diagram of a divided scanning device disclosed in Japanese Patent Application Laid-Open No. 10-177147.

FIG. 19 is a diagram showing an outline of a divided scanning device disclosed in Japanese Patent Application Laid-Open No. 10-177147.

FIG. 20A is a side view showing an outline of a divided scanning device according to a first embodiment disclosed in Japanese Patent Application Laid-Open No. 10-206761, and FIG. 20B is an outline of a divided scanning device according to a second embodiment. FIG.

FIG. 21 is a diagram showing a rotation direction of a reflecting mirror disclosed in Japanese Patent Application Laid-Open No. 10-206761.

[Explanation of symbols]

 Reference Signs List 10 division scanning device 12a semiconductor laser light source 12b semiconductor laser light source 14a collimator lens 14b collimator lens 16a slit 16b slit 18a cylindrical lens 18b cylindrical lens 20a reflection mirror 20b reflection mirror 22 polygon mirror 24fθ lens 26a cylindrical mirror 44b cylindrical mirror 44b cylindrical mirror Lens barrel 46 Lens barrel 48 Restriction member 50 Elastic member 52 Rotating shaft 54 Support member 55 Holding member 56 L-shaped member 58 Screw 60 Elastic member 62 Holding member 64 Support member 66 Screw 70 Folded reflecting mirror

Claims (11)

[Claims] 1. A light source for emitting a light beam, a first imaging optical system provided for each of the light sources, and configured to form an image of a light beam emitted from the light source into a predetermined beam shape; A rotating polyhedron for deflecting two light beams incident from the first imaging optical system at different angles in a direction and a sub-scanning direction, respectively, on a same plane, and a reflecting surface smaller than the width of the light beam; A second imaging optical system for linearly imaging the two light beams deflected by the rotating polyhedron; and the two light beams deflected by the rotating polyhedron through the second imaging optical system to be individually scanned. Guiding means for guiding on a medium and performing divided scanning; scanning position adjusting means for adjusting a scanning position of the two light beams on the medium to be scanned; and light beams on the medium to be scanned of the two light beams Adjust the diameter A split beam scanning device, comprising: a beam diameter adjusting unit that adjusts a light beam amount of the two light beams on the medium to be scanned. 2. The divided scanning device according to claim 1, wherein said guide means comprises an optical member for converging the light beam in a sub-scanning direction. 3. The apparatus according to claim 1, wherein said scanning position adjusting means comprises a main scanning position adjusting means for adjusting a main scanning position and a sub-scanning position adjusting means for adjusting a sub-scanning position. The split scanning device according to claim 1. 4. The divided scanning device according to claim 3, wherein the main scanning position adjustment unit performs the adjustment by controlling a writing start timing in a main scanning direction. 5. The divided scanning according to claim 3, wherein the sub-scanning position adjusting unit performs the adjustment by at least controlling the rotational movement of the guide unit and the writing timing in the sub-scanning direction. apparatus. 6. The divided scanning according to claim 3, wherein the sub-scanning position adjusting unit performs the adjustment by moving the guiding unit in the sub-scanning direction. apparatus. 7. The beam diameter adjusting means comprises a main scanning beam diameter adjusting means for adjusting a beam diameter in a main scanning direction, and a sub-scanning beam diameter adjusting means for adjusting a beam diameter in a sub-scanning direction. Any one of claims 1 to 6
A split scanning device according to the item. 8. The split scanning apparatus according to claim 7, wherein the main scanning beam diameter adjusting means performs adjustment by moving a focal position of the light beam emitted from the light source. 9. The split scanning device according to claim 7, wherein the sub-scanning beam diameter adjusting unit performs the adjustment by tilting a cylindrical lens that forms the first optical system. . 10. The division according to claim 1, wherein the light amount adjusting means performs the adjustment by moving at least the light source or changing the light amount of the light source. Scanning device. 11. A light source for emitting a light beam, a first imaging optical system provided for each of the light sources, and configured to image the light beam emitted from the light source into a predetermined beam shape;
A rotating polyhedron for deflecting two light beams incident from the imaging optical system at different angles in the main scanning direction and the sub-scanning direction on the same plane and a reflecting surface narrower than the width of the light beam; and A second imaging optical system for linearly imaging the two deflected light beams, and the two light beams deflected by the rotating polyhedron through the second imaging optical system individually onto a medium to be scanned And a guiding means for performing divided scanning.A beam state adjusting method of a divided scanning device, comprising: a coarse adjustment of a light amount at a joint portion of each of the light beams emitted from the two light sources; After the coarse adjustment of the sub-scanning position at the joint of the two light beams divided and scanned on the medium to be scanned is performed, the connection of the two light beams divided and scanned on the medium to be scanned is performed. After adjusting the focal positions in the main scanning direction and the sub-scanning direction at the joints, and adjusting the main scanning and the sub-scanning positions at the joints of the light beams that are divided and scanned by the guide means, A method for adjusting a beam state of a divided scanning device, comprising: adjusting a light amount.