JP2010210916A - Optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new optical scanner in which optical output levels of a plurality of beams are adjustable at arbitrary returning paths in reciprocal optical scanning strokes within an appropriate time. <P>SOLUTION: The optical scanner includes: a plural light beams generating means 11; a beam deflection means 14 which deflects the generated plural light beams toward a photoreceptor 19; a matrix beam deflection means 10 which has a plurality of optical deflecting elements which correspond to each of the light beams from the plural light beams generating means 11 and selectively change the deflection directions of the corresponding light beams; a control means Ctr which controls the deflection directions of the optical deflection elements so that, in the reciprocal scanning on the photoreceptor 19, an arbitrary group of the optical deflection elements deflect the corresponding light beams in the scanning direction of the photoreceptor 19 in forward strokes, and the arbitrary group of the optical deflection elements deflect the light beams in the directions (B1 to B3) other than scanning direction in returning strokes; an optical detection element 17 which detects the light quantity of the deflected light beams; and an optical output control means 80 which allows the plural light beams generating means to control the light quantity of the corresponding light beams on the basis of the detected result. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning apparatus and an image forming apparatus provided with an optical path branching unit for detecting the light intensity of a light beam, and more particularly to an optical scanning apparatus and an image forming apparatus using a light source array such as a surface emitting sensor (VCSEL array) or an LD array. .

In conventional optical scanning devices, a polygon mirror is often used as an optical deflector that scans a light beam. The polygon mirror rotates at high speed and scans the light beam. However, in the image formation using the polygon mirror, it is necessary to rotate the polygon mirror at higher speed in order to achieve a higher resolution image and higher speed image formation. is there. However, in order to achieve high-speed rotation of the mirror, it is necessary to improve the durability of the bearing and solve the problems that need countermeasures against heat generation and noise, so use a rotating body with a mirror formed There is a limit to the high speed scanning.
Therefore, in recent years, an optical scanning device that scans a light beam has been proposed that swings a micro mirror using silicon micromachining technology. Such micromirror devices are roughly classified into their driving methods, for example, an electromagnetic driving method as described in Patent Document 1 and an electrostatic driving method as described in Patent Document 2. In these systems, the driving voltage for driving the movable part of the micromirror is constantly applied as a sine wave AC signal.
As a typical example using the electrostatic induction generating means, there is an optical scanning device that swings a mirror by electrostatic attraction as disclosed in Patent Document 3.

Two methods are currently used for electrostatic driving.
One is a system in which the driving electrode has a parallel plate electrode configuration, and the other has a comb-shaped electrode configuration described in Patent Documents 4-6. The comb-shaped electrode method is generally said to be greatly superior to the parallel plate electrode method in terms of both fluctuation amount and driving force.
Such an optical scanning device using silicon micromachining technology is capable of high-speed scanning as compared with the optical scanning device using the polygon mirror, and the size of the micromirror device can be realized with a few millimeters. It is possible to reduce the size.
Furthermore, as another means for achieving high-speed and high-density optical scanning, there is a method of scanning a plurality of light beams at a time and simultaneously scanning a plurality of lines.
As a multi-beam light source device capable of scanning a plurality of light beams, a method using one multi-element light source that generates a plurality of light beams, that is, a laser array light source having a plurality of light emitting points in one package, There has been proposed a method of forming a plurality of light source devices by using a plurality of laser light sources having one light emitting point in one package.

As the light source, a semiconductor laser (LD: Laser Diode) is generally used. In the past, an edge-emitting laser has been the mainstream of the LD, but in recent years, a so-called surface-emitting laser (VCSEL: Vertical Cavity Surface Emitting Laser) has been proposed. Since this surface-emitting laser is easier to array than conventional edge-emitting lasers, the edge-emitting laser has a limit of several beams, whereas the surface-emitting laser has 16 beams or more. Arraying is possible. As a result, it is expected as a light source for improving the printing speed and writing density of the image forming apparatus.
Therefore, by combining a micromirror device and a surface emitting laser, it is possible to achieve higher speed and higher density optical scanning. However, when a light source using a surface emitting laser is mounted on an optical scanning device. Has the following problems compared to the case of the edge emitting laser.
That is, the edge emitting laser uses so-called APC (Auto Power Control) control that adjusts the light output level by feeding back while monitoring the outgoing light. On the other hand, since the surface emitting laser cannot realize backward emission due to its structure and cannot use the backward emitted light, it is necessary to adjust the light amount by other means. In the output image of the image forming apparatus using the light source device that cannot perform the light amount adjustment, there is a problem that the density variation due to the light output variation of the light source device occurs and the image quality deteriorates.
Therefore, as a means for adjusting the amount of light when a surface emitting laser is used, a part of a certain proportion of the light beam emitted from the surface emitting laser is branched and guided to the photodetector, and the photodetector Conventionally, it has been proposed to drive the surface emitting laser by controlling the drive current so that the light output of the surface emitting laser becomes a predetermined output by the laser light quantity adjusting device in accordance with the output of.

  For example, Patent Document 7 proposes that light transmitted through a beam deflection element is guided to a light detection element, and light amount control is performed according to the output result of the light detection element. Patent Document 8 discloses that a part of beam light is branched as monitor light using a beam splitter and guided to a photodetector. Patent Document 9 discloses a method of reflecting a part of a light beam with a half mirror and detecting the amount of light with a light receiving element. Patent Document 10 discloses that the light amount adjustment of each element of a plurality of beams adjusts the light amount of each of the other elements based on the light amount of the light beam from the representative element of the plurality of beams.

However, the techniques disclosed in Patent Documents 7 to 10 have the following problems. That is, 100% of the amount of laser light emitted from the laser light source cannot be used for image formation, the light utilization efficiency is low, and in order to obtain the required amount of light, it is necessary to increase the drive current, There is a problem that problems such as heat generation and change in divergence angle occur due to an increase in driving current.
Now, the present inventor has developed an optical scanning device using a plurality of beams composed of 40 beams. It is obvious that timely adjustment of the light amount of each element of 40 beams is essential for improving image quality, as disclosed in the patent document. However, when a large number of plural beams are used, there are the following problems.
First, fluctuations in the amount of light between the beams have a significant effect on image quality degradation, and individual light amount adjustment is required.

Further, it is necessary to drive a large number of light beams at the time of image formation, and it is essential to obtain an appropriate light amount with a small driving current. For this purpose, as disclosed in the patent document, branching the light beam and guiding a light beam using a divided light quantity of 100% or less to the light detector causes a decrease in light efficiency.
In addition, the method disclosed in Patent Document 10 in which the light amount of each of the other elements is adjusted based on the light amount of the light beam from a plurality of representative elements has a variation between the representative elements when the representative elements are set. Consideration is necessary, and the control processing becomes complicated.
Furthermore, APC (Auto Power Control) control is ideally performed for each scanning cycle. However, a method for executing a plurality of beams within an appropriate time is disclosed in the above-mentioned patent document. There is no disclosure example and a new proposal is required.
In view of the above problems, the present invention provides a new optical scanning device capable of adjusting the optical output level of a plurality of plural beams within an appropriate time in an arbitrary return path during reciprocating optical scanning. It is an object.

  In order to solve the above problems, the invention of claim 1 is directed to a plurality of light beam generating means having a matrix light emitting element structure for generating a plurality of light beams, and a plurality of light beams generated from the plurality of light beam generating means. A beam deflecting means for deflecting the light beam toward the photosensitive member, and corresponding to each of the plurality of light beams generated from the plurality of light beam generating means, and a corresponding light beam deflection direction. Matrix beam deflecting means having a plurality of light deflecting elements that can be selectively changed, and at the time of reciprocal scanning with respect to the photosensitive member, in the forward path, among the plurality of light deflecting elements, any group of light deflecting elements, The corresponding light beam is deflected in the scanning direction with respect to the photosensitive member, and in the return path, the arbitrary group is deflected in at least one direction other than the scanning direction. A light deflection element control means for controlling a deflection direction of the light deflection element, a light detection element provided in the at least one direction, receiving a light beam deflected in the direction, and detecting a light quantity of the light beam; An optical scanning apparatus comprising: a light output control unit that causes the plurality of light beam generation units to adjust the light amount of a light beam corresponding to the detection result based on a detection result of the detection element.

According to a second aspect of the present invention, the light deflection element is configured to reflect a plurality of electrodes provided on one surface of the substrate and a column functioning as an electrode, and the light beam supported at one point by the column. An electrode for applying a voltage among the plurality of electrodes, the reflector being displaceable by an electrostatic force generated by a potential difference between one of the plurality of electrodes and the support; The optical scanning device according to claim 1, wherein the deflection direction of the optical deflection element can be controlled by switching between the two.
According to a third aspect of the present invention, the deflection direction of the plurality of light deflection elements can be switched individually and selectively for each light deflection element by a switching designation signal for the plurality of electrodes. Features an optical scanning device.
According to a fourth aspect of the present invention, the matrix beam deflecting unit is provided in the middle of an optical path connecting the plurality of light beam generating units and the beam deflecting unit. Features an optical scanning device.

According to a fifth aspect of the present invention, the light deflection element is capable of adjusting a deflection angle by changing a height of the support column, and light deflected in a direction other than the scanning direction in the matrix beam deflection unit. The light according to any one of claims 1 to 4, wherein when the beam is emitted in one direction other than the scanning direction, the deflection angle is adjusted so that the light beam converges to the same convergence point. Features a scanning device.
According to a sixth aspect of the present invention, the light deflection element is capable of adjusting a deflection angle by changing the height of the support column, and the light deflected in a direction other than the scanning direction by the matrix beam deflection unit. The light according to claim 1, wherein when the beam is emitted in a plurality of directions other than the scanning direction, the deflection angle is adjusted so that the light beam converges at a plurality of convergence points. Features a scanning device.
According to a seventh aspect of the invention, there is provided an image forming apparatus including the optical scanning device according to any one of the first to sixth aspects.

  With the configuration as described above, according to the optical scanning device of the present invention, an arbitrary part of the plurality of light beams incident on the matrix optical polarizer is emitted in the scanning direction in any forward path of the reciprocating scanning. In the return path, the light beam is controlled to be emitted in the other direction, so that the light beam is simultaneously scanned for other purposes, that is, the light output detection and the adjustment of the light output level based on the detection result. Can be usable. Accordingly, it is possible to provide a new optical scanning device that can adjust the optical output level of a plurality of beams within an appropriate time in an arbitrary return path during reciprocating optical scanning.

The figure which shows the outline | summary of a structure of the optical scanning device of this invention. The figure which shows the other structure of the optical scanning device of this invention. The figure which shows the example of the multiple light beam generation means of 40 elements. FIG. 2 is a schematic cross-sectional view showing a configuration of one light emitting element of a surface emitting laser. The figure which shows the structure of a micro scanner. The schematic structure figure of a light beam deflection element. The figure which shows that the inclination-angle of the movable plate of a light beam deflection | deviation element can be set. The figure explaining the outline of the principle of operation of the beam deflection element. The figure which applied the displacement state of the movable plate to the A direction of FIG. 1, and the B1-B3 direction. The figure which showed typically a mode that the some beam radiate | emitted from the several light beam generation means was deflected by the beam deflection element, and was guide | induced to the light beam output amount detector. The figure which showed typically a mode that the several beam radiate | emitted from the several light beam generation means was deflected by the beam deflection | deviation element, and was guide | induced to the several light beam output amount detector. The figure which shows the example by which the one light beam output amount detector is comprised from the several detection part. The figure which shows the structure which added the optical output control means. The figure which compares the state of the light beam in the light beam scanning period to the conventional image carrier, and the state of the light beam in the case of this invention. The figure explaining the light beam deflector of FIG. The figure explaining the light beam deflector of FIG. 1 is a schematic diagram of an image forming apparatus using an optical scanning device according to the present invention.

Embodiments of the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a diagram showing an outline of the configuration of the optical scanning device of the present invention.
As shown in FIG. 1, the optical scanning device of the present invention includes a plurality of light beam generating means 11 which is a surface emitting laser, a coupling lens 12 for converting the light beam into parallel light, and a plurality of light emitting elements of the surface emitting laser. A matrix light beam deflecting means (microscanner) 10 for individually deflecting each light beam, a first optical system 13, and a plurality of light beams as an image carrier. A light beam deflector (beam changing means) 14 that deflects in the (photosensitive member) direction, a second optical system 15, a light synchronization detector 16, and a light beam output amount detector (light detection element) 17 are provided.
As shown in FIG. 1, the plurality of beams emitted from the plurality of light beam generating means 11 reach the micro scanner 10 through the coupling lens 12 and pass through the second optical system 15 on the image carrier 19. To form a latent image 18.

Here, the micro scanner 10 of the present invention has a matrix structure of a plurality of light beam deflecting elements, and is disposed on the optical path to the light beam deflector 14 of the plurality of light beams generated from the plurality of light beam generating means 11. ing.
The light beam deflecting element of the microscanner 10 oscillates at a constant cycle so that the deflected plural light beams perform reciprocal light scanning at a constant cycle. The light beam deflecting element has an arbitrary direction depending on the configuration described later. The optical path of the light beam incident on the movable plate of each light beam deflection element can be selectively switched.
That is, as shown in FIG. 1, the microscanner 10 switches the optical paths of a plurality of light beams to, for example, the A direction (scanning direction) toward the first optical system 13 and the other B directions (B1 to B3). Is possible.
Therefore, in reciprocal light scanning, an arbitrary light beam is deflected in the A direction on the forward path, and is deflected in the B direction or a plurality of B directions on the return path, and is deflected in the B direction on the outbound path. In the return path, scanning can be performed by deflecting the light beam in the direction A and scanning.

In FIG. 1, the light beam incident on the light beam output amount detector 17 arranged in the B2 direction is shown. However, the light beam is deflected in the B direction while performing optical scanning on the surface of the image carrier 19. This means that the plurality of beams can be used simultaneously for other purposes.
In addition, the displacement operation (switching between the A direction and the B direction) of each beam deflection element in the micro scanner 10 can be performed individually by a switching designation signal from the light deflection element control unit (light deflection element control means) Ctr. As a result, the light beam guided in the direction of the light beam output amount detector 17 and the light beam guided in the direction of the image carrier can be selected appropriately and appropriately.
The light deflection element control unit Ctr is described as being provided in the optical scanning device, but may be controlled by the control unit of the image forming apparatus having the optical scanning device.

FIG. 2 is a diagram showing another configuration of the optical scanning device of the present invention.
1A shows a configuration in which the light beam output amount detector 17 is disposed in the B3 direction in FIG. 1, FIG. 1B in the B2 direction, and FIG. 1C in the B1 direction. As described above, the degree of freedom of the arrangement position of the light beam output amount detector 17 can be secured by arbitrarily changing the deflection direction of the light beam deflection element.
Below, each structure of the optical scanning device of this invention is demonstrated in detail.
First, the configuration of the surface emitting laser 11 will be described.
FIG. 3 is a diagram showing an example of 40 elements of the multiple light beam generating means 11.
As can be seen from FIG. 3, the surface emitting laser 11 includes 40 light emitting elements 20, but is not limited to this number.

FIG. 4 is a schematic cross-sectional view showing the configuration of one light emitting element of the surface emitting laser 11.
In FIG. 4, the light emitting element 20 includes an emission port 21 for emitting laser light, a P-type electrode 22, a contact layer 23, an oxide constriction 24, an insulating film 25, an active region 26, a lower reflective film 27, a semiconductor substrate 28, n. It comprises a mold electrode 29 and an upper reflective film 30.
The injected current is confined in the central portion of the active region 26, the current density is increased, and laser oscillation occurs. The light output direction is one direction of the emission port 21. For this reason, the light quantity adjustment of the laser beam must use the light beam in one direction. This is as described in the description of the background art.
Next, the configuration of the micro scanner 10 in FIG. 1 will be described.
FIG. 5 is a diagram showing the configuration of the micro scanner of the present invention, and shows an example of 40 light beam deflecting elements 40.
2A shows a state in which a part of the light beam deflecting element 40 is rotated and tilted. FIG.
In FIG. 5, the number of light beam deflecting elements is 40, but is not limited to this number, and corresponds to the number of light emitting elements of the surface emitting laser.

6A and 6B are schematic structural views of the light beam deflecting element, where FIG. 6A is a schematic perspective view, FIG. 6B is a schematic perspective view of the movable plate taken off, and FIG. 6C is a cross-sectional view showing the structure of the movable plate. FIG.
As shown in (a), the light beam deflecting element 40 includes a movable plate 41 as a reflecting plate that actually moves and deflects the light beam, and further, as shown in (b), the insulating film 42. , The substrate 43, the regulating member 44, the electrodes 45 (A to D), and the support column 47.
Specifically, electrodes 45A, 45B, 45C, and 45D are disposed on the substrate 43 via the insulating film 42 so as to face the substrate 43, and the electrode surfaces are covered with an insulating film (not shown). The support 47 also has an electrode function.
Here, an example in which the number of electrodes is four is shown, but any number of poles can be set as necessary.
As shown in (c), the movable plate 41 includes a light beam reflecting portion 41A and a conductor layer 41B. In the state shown in (a), the conductor layer 41B is electrically connected to the support column 47, and the conductor layer 41B. A potential can be applied to the.
Further, the movable plate 41 is restricted in moving distance by the restricting member 44, and can be tilted in an arbitrary direction at a constant angle.
FIG. 7 is a diagram for further explaining the schematic structure of the light beam deflecting element. As can be seen from FIG. 7, the tilt angle of the movable plate 41 can be set by the combination of the support column 47 and the regulating member 44.
The manufacturing method of the light beam deflecting element 40 can be realized using the method disclosed in Japanese Patent Application Laid-Open No. 2007-199096. That is, it can be manufactured using a semiconductor manufacturing process or a microelectric machine system manufacturing process.

FIG. 8 is a diagram for explaining the outline of the operation principle of the beam deflection element 40.
(A) is a figure which shows the state of the movable plate 41 of an initial state, and the electric potential state of each electrode, (b) has shown the state of the movable plate at the time of a certain rotation inclination, and the electric potential state of each electrode.
The movable plate 41 is not fixed to other members. The central portion of the movable plate 41 is in contact with the upper portion of the support column 47 and is inclined to the arbitrary electrode side as a whole.
(1) In the initial state, the potentials of the electrodes D, C, and A (TD, TC, TA) are 0 volts, the fulcrum potential (P0) Ep volts, and the electrode B (TB) is E1 volts. That is, the potential difference between the electrode D and the fulcrum is larger than the potential difference between the electrode B and the fulcrum.
(2) From the state (1), the fulcrum potential is changed from Ep volts to 0 volts. Then, the potential difference between the electrode D and the fulcrum becomes the same potential, the potential difference between the electrode B and the fulcrum becomes E1 volts, electrostatic attraction works between the electrode B and the movable plate 41, and the movable plate 41 moves toward the electrode B side. It rotates and tilts, and the state shown in FIG.
In this way, by selectively applying a potential to the electrodes A, B, C, D and the fulcrum, the movable plate 41 can be rotated and inclined in any direction. Four displacement states can be taken that are inclined and displaced toward the electrode A side, B side, C side, and D side.
FIG. 9 is a diagram in which the displacement state of the movable plate 41 is applied to the A direction and the B1-B3 direction in FIG.
Note that the displacement operation of the movable plate toward each electrode is individually performed for each light deflection element 40 in response to a switching designation signal from a control unit (not shown), so that the light beam deflection direction (A direction, B1-B3) can be selected appropriately and appropriately.

FIG. 10 is a diagram schematically showing a state in which a plurality of beams emitted from the plurality of light beam generating means 11 are deflected by the beam deflecting element 40 and guided to the light beam output amount detector 17.
In FIG. 10, a single light beam output amount detector 17 is configured to detect a plurality of light beams.
In such a configuration, when a plurality of incident light beams are deflected and emitted as a function of the beam deflecting element 40, it is necessary to be guided accurately to the detection unit of the light beam output amount detector 17. Therefore, each beam deflection element 40 is set to have a different deflection angle so that the emitted light from each beam deflection element 40 is guided to the same point of the light beam output amount detector 17. In this way, each light beam can be appropriately incident on one light beam output amount detection unit 17.
The setting of the deflection angle can be determined by a combination of the dimension in the height direction of the column 47 and the dimension in the height direction of the regulating member 44 as shown in FIG.

Further, FIG. 11 schematically shows a state in which a plurality of beams emitted from the plurality of light beam generating means 11 are deflected by the beam deflecting element 40 and guided to the plurality of light beam output amount detectors 17.
In FIG. 11, a plurality of light beam output amount detectors 17 (four in the figure) are configured to detect a plurality of light beams one by one. In such a configuration, when a plurality of incident light beams are deflected and emitted as a function of the beam deflecting element 40, the light deflector 17 is suitable for the detection unit of each light beam output amount detector 17 (17-1 to 17-4). Need to be guided. Therefore, each beam deflection element 40 is set to have a different deflection angle so that the emitted light from each beam deflection element 40 is guided to the detection areas of the plurality of light beam output amount detectors 17. .
In this way, each light beam can be appropriately incident on the plurality of light beam output amount detectors 17.

FIG. 12 is a diagram illustrating an example in which one light beam output amount detector 17 includes a plurality of detection units. Also in this case, as in the case of FIG. 11, if each beam deflection element 40 is set to have a different deflection angle, the light beam can be appropriately incident on each detection unit.
11 and 12, the setting of the deflection angle can be adjusted by a combination of the height dimension of the support column 47 and the height dimension of the regulating member 44 as shown in FIG. 6.
FIG. 13 is a diagram showing a configuration in which the light output control means 80 is added.
Based on the output result of the light beam output quantity detector 17 corresponding to a plurality of light beams, the light output control means 80 can adjust the light output of the light beam.

FIG. 14 is a diagram for comparing the state of the light beam in the light beam scanning period on the conventional image carrier with the state of the light beam in the case of the present invention. FIG. 14A shows the state of the light beam in the conventional case. (B) is a figure which shows the case of this invention.
The light beam that scans the surface of the image carrier is detected by a synchronous detector, and the output signal is used as a trigger to cause the light beam to blink in a timely manner in the carrier scanning region, thereby forming an image on the image carrier. An APC operation is performed in an APC (Auto Power Control) operation region that is out of the carrier scanning region, and the light output level of the corresponding light beam is adjusted. As shown in FIG. 14A, conventionally, in this APC operation region, the light output adjustment of the light beam is limited to a maximum of 8 beams because of the relationship with the adjustment time.
In the case of the multiple light beam generating means having a 40-beam matrix configuration as the multiple multiple light beam generating means 11 used in the present invention, the light output of all the light beams can be adjusted in the conventional APC operation region. Absent.
Therefore, as shown in FIG. 14B, within the light beam scanning period to the image carrier, the light output other than the light beam that scans the surface of the image carrier can be adjusted simultaneously. Provided by the present invention. In the APC operation area 1 shown in FIG. 14B, the light output of a light beam other than the light beam emitted on the surface of the carrier can be adjusted. In the APC area 2, the light beam used in the carrier scanning area. The optical output can be selectively adjusted.

Next, the configuration of the light beam deflecting means 14 in FIG. 1 will be described.
FIG. 15 is a diagram illustrating a first example of the light beam deflecting unit 14.
Both ends of the movable plate 62 are supported by elastic support portions 63 on a support substrate 61 made of silicon. A movable electrode 65 and a reflective surface 66 are provided on the end surface of the movable plate 62, and a fixed electrode 64 is provided at a position facing the movable electrode 66. A gap of, for example, 5 μm is provided between the movable electrode 65 and the fixed electrode 64 facing the movable electrode. By applying a voltage between these electrodes, an electrostatic attractive force acts between the electrodes, and the end surface of the movable plate 62 Is attracted to the fixed electrode 64.
The operation of the optical deflector configured as described above will be described with reference to FIG.
In FIG. 15, the movable electrode 65 attached to the movable plate 62 is grounded via a pad (not shown) drawn to the support substrate 61.
15, when the positional relationship between the fixed electrode 64 and the movable electrode 65 is the state shown in FIG. 15B (A), when a voltage of, for example, 30 V is applied to the fixed electrode 64, the fixed electrode 64 and the movable electrode 66 are not connected. The movable plate swings clockwise in the figure due to the electrostatic force acting on and the torsional rigidity of the beam.
Thereafter, as shown in FIG. 15B (B), when the voltage application to the fixed electrode 64 is turned OFF when the movable plate 62 reaches the horizontal position, the movable plate 62 is rotated clockwise by the moment of inertia. Further shakes. Finally, as shown in (C) of FIG. 15B, it swings to a position where the moment of inertia and the torsional rigidity of the beam balance. When it reaches the maximum deflection angle, it pauses and starts shaking in the opposite direction. That is, in FIG. 15B, it starts to swing counterclockwise. When a voltage is applied again to the fixed electrode 64 at an appropriate time after starting to swing counterclockwise, the movable plate 62 rotates counterclockwise in the figure due to the electrostatic force acting between the fixed electrode 64 and the movable electrode 66 and the torsional rigidity of the beam. Swing. When the voltage application to the fixed electrode 64 is turned off when the movable plate reaches the horizontal position again, the movable plate 62 further swings counterclockwise due to the moment of inertia.
Finally, as shown in (A) of FIG. 15 (b), it swings to a position where the moment of inertia and the torsional rigidity of the beam are balanced.
By adjusting the voltage application frequency to the fixed electrode 64 to the resonance frequency of the movable plate 62, the movable plate 62 can be swung with a large deflection angle.

FIGS. 16A and 16B are diagrams illustrating a second example of the light beam deflecting unit 14, where FIG. 16A is a schematic perspective view, and FIG. 16B is a diagram illustrating a state during operation.
The end of the mirror substrate 72 that is not supported by the beam 73 has a comb-tooth shape, and the comb-shaped movable electrode 75 provided at the end and the same comb-tooth shape provided on the inner frame 71 of the same portion. It is opposed to the fixed electrode 74 that is driven in such a manner as to mesh with a small gap. This comb-teeth shape acts as a drive electrode, and the mirror substrate 72 swings around the beam 73 as a rotation axis as shown in FIG.
By making both the electrodes 74 and 75 into a comb-teeth shape, the electrode area can be increased, so that the driving torque can be further increased, and the deflection angle of the movable plate can be further increased.
When the reflection surface 5 of the movable plate (mirror substrate) 72 that swings in this way is irradiated with a light beam, incident light can be deflected by the reflection surface 76 by the swing of the movable plate 72.

FIG. 17 is a schematic view of an image forming apparatus using the optical scanning device according to the present invention.
A charging unit 144, an optical scanning device 143, a developing unit 142, a transfer unit 149, and a cleaning unit 146 are arranged around the photoconductor 145, and when the start of image formation is instructed by the image forming apparatus control unit 153, the photoconductor 145. Is rotated clockwise as shown in the figure, and the optical writing means 143 drives the optical scanning device to generate a synchronizing signal, the charging means 144 charges the photosensitive member, and the optical writing means 143 provides an external input not shown. Corresponding to the image data input from the apparatus, a light beam is generated using the beam generator 152 in synchronization with the synchronization signal, and a latent image is formed on the surface of the photoconductor 145.
Integer value image data of 0 to 255 representing the gradation value of the image is input, and the beam emission time setting data for setting the beam emission time (width) corresponding to the input data is supplied to the beam generator, and the beam The signal generated by the generating unit is supplied to the beam driving unit and supplies a current to a laser diode which is a light emission source, thereby causing the laser diode to emit light and generating a beam that forms a latent image on the surface of the photoreceptor. The developing unit 142 obtains a visualized image using an image visualization agent. The paper stored in the paper storage unit 140 is fed by the paper feeding unit 141, and the registration unit 151 can match the paper conveyance timing and writing timing to transfer a visible image by the image visualization agent to a predetermined position by the transfer unit 149. And
The actual image transferred by the image visualization agent transferred onto the paper is fixed by the fixing unit 147, and the input image data is visualized and fixed on the paper.

DESCRIPTION OF SYMBOLS 10 Micro scanner, 11 Multiple light beam generating means, 11 Surface emitting laser, 12 Coupling lens, 13 1st optical system, 14 Light beam deflector, 15 2nd optical system, 16 Light synchronous detector, 17 Light beam Output quantity detector, 18 latent image, 19 image carrier, 20 light emitting element, 21 exit port, 22 P-type electrode, 23 contact layer, 24 oxidation constriction, 25 insulating film, 26 active region, 27 lower reflective film, 28 Semiconductor substrate, 29 n-type electrode, 30 Upper reflective film, 40 Light beam deflecting element, 41 Movable plate, 41A Light beam reflecting portion, 41B Conductor layer, 42 Insulating film, 43 Substrate, 44 Restricting member, 45 Electrode, 47 Support point 61 Support substrate, 62 Movable plate, 63 Elastic support part, 64 Fixed electrode, 66 Movable electrode, 80 Light output control means, 140 Paper storage part, 141 Paper feeding means, 142 Developing means, 143 Optical scanning device, 143 means, 144 charging means, 145 photoconductor, 146 cleaning means, 147 fixing means, 149 transfer means, 151 resist section, 152 beam generating apparatus, 153 image forming apparatus control Part

JP 2002-78368 A JP-A-8-213320 Japanese Patent No. 30111144 Japanese Patent No. 3006178 Japanese Patent Application Laid-Open No. 5-224751 JP 2003-241120 A JP 2007-79487 A JP-A-8-330661 Japanese Patent Laid-Open No. 2002-40350 JP 2007-329436 A

Claims (7)

A plurality of light beam generating means having a matrix light emitting element structure for generating a plurality of light beams;
A beam deflecting unit configured to deflect a plurality of light beams generated from the plurality of light beam generating units toward the photosensitive member,
Matrix beam deflecting means corresponding to each of the plurality of light beams generated from the plurality of light beam generating means, and having a plurality of light deflecting elements capable of selectively changing the deflection direction of the corresponding light beam;
During reciprocal scanning with respect to the photoconductor, an optical deflection element of an arbitrary group among the plurality of optical deflection elements deflects a corresponding light beam in a scanning direction with respect to the photoconductor in the forward path, and the arbitrary optical path in the backward path. A group of optical deflection element control means for controlling the deflection direction of the optical deflection element to deflect in at least one direction other than the scanning direction;
A light detection element that is provided in the at least one direction and receives a light beam deflected in the direction and detects a light amount of the light beam;
An optical scanning apparatus comprising: a light output control unit that causes the plurality of light beam generation units to adjust a light amount of a light beam corresponding to the detection result based on a detection result of the detection element.   The light deflection element includes a plurality of electrodes provided on one surface of a substrate, a support column functioning as an electrode, and a reflection plate for reflecting the light beam supported at one point by the support column. Is displaceable by an electrostatic force generated by a potential difference between one of the plurality of electrodes and the support column, and by switching an electrode to which a voltage is applied among the plurality of electrodes, The optical scanning device according to claim 1, wherein the deflection direction can be controlled.   3. The optical scanning device according to claim 2, wherein the deflection directions of the plurality of light deflection elements can be switched individually and selectively for each light deflection element by a switching designation signal for the plurality of electrodes.   4. The optical scanning device according to claim 1, wherein the matrix beam deflecting unit is disposed in the middle of an optical path connecting the plurality of light beam generating units and the beam deflecting unit. The light deflection element is capable of adjusting the deflection angle by changing the height of the column.
In the matrix beam deflecting means, when the light beam deflected in the direction other than the scanning direction is emitted in one direction other than the scanning direction, the deflection angle is set so that the light beam converges at the same convergence point. The optical scanning device according to claim 1, wherein the optical scanning device is adjusted. The light deflection element is capable of adjusting the deflection angle by changing the height of the column.
In the matrix beam deflecting means, when the light beam deflected in a direction other than the scanning direction is emitted in a plurality of directions other than the scanning direction, the deflection angle is set so that the light beam converges at a plurality of convergence points. The optical scanning device according to claim 1, wherein the optical scanning device is adjusted.   An image forming apparatus comprising the optical scanning device according to claim 1.

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