JP5505590B2 - Optical scanning apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanning apparatus and an image forming apparatus, and more particularly to an optical scanning apparatus that scans a surface to be scanned with a light beam and an image forming apparatus including the optical scanning apparatus.

  In electrophotographic image recording, image forming apparatuses such as printers and digital copying machines using laser light are widely used. This image forming apparatus includes an optical scanning device, and scans a laser beam using a deflector (for example, a polygon mirror) in the axial direction of a photosensitive drum (hereinafter also referred to as a “photosensitive drum”) while performing a photosensitive operation. A general method is to form a latent image on the surface (scanned surface) of the photosensitive drum by rotating the photosensitive drum.

  The optical scanning device converts a light beam deflected by a deflector into a light beam that scans the surface of the photosensitive drum at a constant moving speed in the main scanning direction, and includes a scanning optical system that focuses the light beam on the surface of the photosensitive drum. Have. When the scanning line on the surface of the photosensitive drum is inclined, the scanning optical system is adjusted to correct the inclination of the scanning line.

  For example, in Patent Document 1, it is possible to generate a change in a scanning line of a change component (third-order or higher-order function curve component) having vertices at a plurality of portions along the main scanning direction, and a scanning line in the reverse mode An optical scanning device is disclosed that includes scanning line change correction means that cancels out the higher-order function curve components of the third order or higher by generating the above change.

  Patent Document 2 discloses a single fixed point that is in contact with one end in the main scanning direction and serves as a common fulcrum for the inclination and bending correction of the scanning line, and a first movable point that operates based on the registration deviation detection result. An image forming apparatus is disclosed that includes a scanning trajectory varying unit that supports an optical element at a second movable point and rotates the optical element in a plane orthogonal to the optical axis to correct the inclination of the scanning line.

  Japanese Patent Application Laid-Open No. 2004-228561 corrects an optical element in the sub-scanning direction of the beam and corrects a scanning line bending correction unit that corrects the bending of the scanning line by the beam, and corrects the inclination of the scanning line by inclining the entire optical element. An optical scanning device having scanning line inclination correction means is disclosed.

JP 2006-184526 A Japanese Patent No. 4107578 JP 2004-287380 A

  However, in the optical scanning device disclosed in Patent Document 1, when a temperature change occurs, asymmetric stress is generated in the support plate that supports the toroidal lens, and the toroidal lens is deformed to change the scanning line curve. There was a risk of it being generated.

  Further, in the image forming apparatus disclosed in Patent Document 2, when the optical element is rotated in order to correct the inclination of the scanning line, there is a possibility that a deviation in beam diameter between image heights may occur.

  Further, in the optical scanning device disclosed in Patent Document 3, when the temperature rises, the internal stress of the optical element is released, and then the posture of the optical element returns to the initial state even if the temperature returns to the initial state. There was a risk that the adjustment value would shift.

  The present invention has been made under such circumstances, and a first object of the present invention is to provide an optical scanning device capable of stably performing high-precision optical scanning.

  A second object of the present invention is to provide an image forming apparatus capable of stably forming a high quality image.

The present invention is, to a first aspect, there is provided an optical scanning apparatus for scanning a scanned surface in the main scanning direction by the light beam, the light source and; wherein run査lens; deflector and to deflect the light beam from the light source A scanning optical system for condensing the light beam deflected by the deflector onto the surface to be scanned; and first and second adjustment mechanisms for adjusting the tilt of the scanning lens . The adjusting mechanism rotates the holding member that holds the scanning lens around a first axis that is parallel to the optical axis of the scanning lens, with an end of the holding member on one side in the main scanning direction as a fulcrum. The second adjustment mechanism is configured to support a support body that supports an end portion of the holding member on one side in the main scanning direction from one side in a direction orthogonal to both the first axial direction and the main scanning direction. Around a second axis parallel to the optical axis, with the other end of the body in the main scanning direction as a fulcrum One end of the holding member in the main scanning direction is pressed against the support by the first leaf spring from the other side in the direction perpendicular to both the first axial direction and the main scanning direction. The other end of the support in the main scanning direction is supported by the support from one side in the direction perpendicular to both the second axial direction and the main scanning direction, and is supported by the second leaf spring. The optical scanning device is pressed against the support from the other side in a direction orthogonal to both the second axial direction and the main scanning direction .

  According to this, it becomes possible to perform stable and highly accurate optical scanning.

  According to a second aspect of the present invention, there is provided at least one image carrier; and at least one optical scanning device according to the present invention that scans the at least one image carrier with a light beam modulated according to image information. And an image forming apparatus.

  According to this, since the optical scanning device of the present invention is provided, as a result, a high-quality image can be stably formed.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a laser printer 1000 as an image forming apparatus according to an embodiment.

  The laser printer 1000 includes an optical scanning device 1010, a photosensitive drum 1030, a charging charger 1031, a developing roller 1032, a transfer charger 1033, a charge eliminating unit 1034, a cleaning unit 1035, a toner cartridge 1036, a paper feeding roller 1037, a paper feeding tray 1038, A registration roller pair 1039, a fixing roller 1041, a paper discharge roller 1042, a paper discharge tray 1043, a communication control device 1050, a printer control device 1060 that comprehensively controls the above-described units, and the like are provided. These are housed in predetermined positions in the printer housing 1044.

  The communication control device 1050 controls bidirectional communication with a host device (for example, a personal computer) via a network or the like.

  The photosensitive drum 1030 is a cylindrical member, and a photosensitive layer is formed on the surface thereof. That is, the surface of the photoconductor drum 1030 is a scanned surface. The photosensitive drum 1030 rotates in the direction of the arrow in FIG.

  The charging charger 1031, the developing roller 1032, the transfer charger 1033, the charge removal unit 1034, and the cleaning unit 1035 are each disposed in the vicinity of the surface of the photosensitive drum 1030. Then, along the rotation direction of the photosensitive drum 1030, the charging charger 1031 → the developing roller 1032 → the transfer charger 1033 → the discharging unit 1034 → the cleaning unit 1035 are arranged in this order.

  The charging charger 1031 uniformly charges the surface of the photosensitive drum 1030.

  The optical scanning device 1010 irradiates the surface of the photosensitive drum 1030 charged by the charging charger 1031 with a light beam modulated based on image information from the host device. As a result, a latent image corresponding to the image information is formed on the surface of the photosensitive drum 1030. The latent image formed here moves in the direction of the developing roller 1032 as the photosensitive drum 1030 rotates. The configuration of the optical scanning device 1010 will be described later.

  The toner cartridge 1036 stores toner, and the toner is supplied to the developing roller 1032.

  The developing roller 1032 causes the toner supplied from the toner cartridge 1036 to adhere to the latent image formed on the surface of the photosensitive drum 1030 to visualize the image information. Here, the latent image to which the toner is attached (hereinafter also referred to as “toner image” for the sake of convenience) moves in the direction of the transfer charger 1033 as the photosensitive drum 1030 rotates.

  Recording paper 1040 is stored in the paper feed tray 1038. A paper feed roller 1037 is disposed in the vicinity of the paper feed tray 1038, and the paper feed roller 1037 takes out the recording paper 1040 one by one from the paper feed tray 1038 and conveys it to the registration roller pair 1039. The registration roller pair 1039 temporarily holds the recording paper 1040 taken out by the paper supply roller 1037, and in the gap between the photosensitive drum 1030 and the transfer charger 1033 according to the rotation of the photosensitive drum 1030. Send it out.

  A voltage having a polarity opposite to that of the toner is applied to the transfer charger 1033 in order to electrically attract the toner on the surface of the photosensitive drum 1030 to the recording paper 1040. With this voltage, the toner image on the surface of the photosensitive drum 1030 is transferred to the recording paper 1040. The recording sheet 1040 transferred here is sent to the fixing roller 1041.

  In the fixing roller 1041, heat and pressure are applied to the recording paper 1040, whereby the toner is fixed on the recording paper 1040. The recording paper 1040 fixed here is sent to the paper discharge tray 1043 via the paper discharge roller 1042 and is sequentially stacked on the paper discharge tray 1043.

  The neutralization unit 1034 neutralizes the surface of the photosensitive drum 1030.

  The cleaning unit 1035 removes the toner remaining on the surface of the photosensitive drum 1030 (residual toner). The surface of the photosensitive drum 1030 from which the residual toner has been removed returns to the position facing the charging charger 1031 again.

  Next, the configuration of the optical scanning device 1010 will be described.

  As shown in FIG. 2, the optical scanning device 1010 includes a deflector-side scanning lens 11a, an image plane-side scanning lens 11b, a polygon mirror 13, a light source unit 14, a coupling lens 15, an aperture plate 16, a cylindrical lens 17, Two light detection sensors (18a, 18b), two light detection mirrors (19a, 19b), a liquid crystal deflecting element 20, a scanning control device 22 (not shown in FIG. 2, refer to FIG. 12), and two stepping motors ( 315, 340) (not shown in FIG. 2, see FIG. 23). These are assembled at predetermined positions in the housing 22.

  The two light detection sensors are the same sensor.

  In this specification, in the XYZ three-dimensional orthogonal coordinate system, the direction along the longitudinal direction of the photosensitive drum 1030 is defined as the Y-axis direction, and the direction along the optical axis of each scanning lens (11a, 11b) is defined as the X-axis direction. explain. In the following, for convenience, the direction corresponding to the main scanning direction is abbreviated as “main scanning corresponding direction”, and the direction corresponding to the sub scanning direction is abbreviated as “sub scanning corresponding direction”.

  As shown in FIG. 3 as an example, the light source unit 14 includes a two-dimensional array 100 in which 40 light emitting units (v1 to v40) arranged two-dimensionally are formed on one substrate. . The M direction in FIG. 3 is the main scanning corresponding direction, and the S direction is the sub scanning corresponding direction. The T direction is a direction inclined with respect to both the M direction and the S direction.

  This two-dimensional array 100 has four light emitting part rows in which ten light emitting parts are arranged at equal intervals along the T direction. And these light emission part row | line | columns are arrange | positioned so that it may become equal intervals, when all the light emission parts are orthogonally projected on the virtual line extended in a S direction. In this specification, the “light emitting portion interval” refers to the distance between the centers of two light emitting portions.

  Each light emitting unit is a vertical cavity surface emitting laser (VCSEL) having an oscillation wavelength of 780 nm band. That is, the two-dimensional array 100 is a so-called surface emitting laser array.

  The light source unit 14 has a drive circuit (not shown) that individually drives each light emitting unit of the two-dimensional array 100. The two-dimensional array 100 and the drive circuit are mounted on a control board (not shown).

  Returning to FIG. 2, here, the light source unit 14 is disposed in the vicinity of the + Y side end of the housing 22.

  The coupling lens 15 converts the light beam output from the light source unit 14 into substantially parallel light.

  The aperture plate 16 has an aperture and defines the beam diameter of the light beam through the coupling lens 15.

  The liquid crystal deflecting element 20 is disposed on the optical path of the light beam that has passed through the opening of the aperture plate 16, and can deflect incident light in the sub-scanning corresponding direction (here, the Z-axis direction) in accordance with the applied voltage. . The liquid crystal deflecting element 20 has a configuration in which liquid crystal is sealed between two transparent glass plates. As an example, as shown in FIG. 4A, electrodes are formed above and below the surface of one glass plate. ing. When a potential difference is applied between the electrodes, as shown in FIG. 4B as an example, a potential gradient occurs in the sub-scanning corresponding direction, and the alignment of the liquid crystal changes accordingly. As a result, the sub-scanning is performed. A refractive index gradient occurs in the corresponding direction. As a result, like the prism, the light emission axis can be slightly tilted with respect to the sub-scanning corresponding direction. As the liquid crystal, nematic liquid crystal having dielectric anisotropy is used.

  Returning to FIG. 2, the cylindrical lens 17 has a strong power in the sub-scanning corresponding direction (here, the Z-axis direction), and supports the light beam that has passed through the liquid crystal deflecting element 20 in the vicinity of the deflection reflection surface of the polygon mirror 13. Imaging with respect to direction. Further, the cylindrical lens 17 forms a surface tilt correction system in the sub-scanning corresponding direction in cooperation with each scanning lens.

  The optical system arranged on the optical path between the light source unit 14 and the polygon mirror 13 is also called a pre-deflector optical system. In the present embodiment, the pre-deflector optical system includes a coupling lens 15, an aperture plate 16, a liquid crystal deflecting element 20, and a cylindrical lens 17.

  The polygon mirror 13 has a four-sided mirror, and each mirror serves as a deflection reflection surface. The polygon mirror 13 rotates at a constant speed around an axis parallel to the Z-axis direction, and deflects the light beam from the cylindrical lens 17.

  The deflector-side scanning lens 11 a is disposed on the optical path of the light beam deflected by the polygon mirror 13.

  The image plane side scanning lens 11b is disposed on the optical path of the light beam via the deflector side scanning lens 11a.

  The light beam that has passed through the image plane side scanning lens 11b is condensed on the surface of the photosensitive drum 1030, and a light spot is formed. This light spot moves in the longitudinal direction of the photosensitive drum 1030 as the polygon mirror 13 rotates. That is, the photoconductor drum 1030 is scanned. The moving direction of the light spot at this time is the “main scanning direction”. The rotation direction of the photosensitive drum 1030 is the “sub-scanning direction”.

The deflector side scanning lens 11a and the image plane side scanning lens 11b are both made of resin. Each of these surfaces (incident surface, exit surface) is an aspherical surface expressed by the following equation (1) and the following equation (2). Here, X represents the coordinate in the X-axis direction, and Y represents the coordinate in the Y-axis direction. The center of the incident surface is Y = 0. C _m0 indicates the curvature in the main scanning corresponding direction at Y = 0, and is the reciprocal of the curvature radius R _m . a ₀₀ , a ₀₁ , a ₀₂ ,... are aspheric coefficients in the main scanning corresponding direction. Cs (Y) is the curvature in the sub-scanning corresponding direction with respect to Y, R _s0 is the radius of curvature on the optical axis in the sub-scanning corresponding direction, b ₀₀ , b ₀₁ , b ₀₂ ,. Spherical coefficient. The optical axis is an axis that passes through the center point in the sub-scanning corresponding direction when Y = 0.

FIG. 5 shows an example of values of R _m , R _s0, and each aspheric coefficient on each surface (incident surface (first surface), exit surface (second surface)) of the deflector-side scanning lens 11a.

FIG. 6 shows an example of values of R _m , R _s0, and each aspheric coefficient on each surface (incident surface (third surface), exit surface (fourth surface)) of the image surface side scanning lens 11b.

  The optical system arranged on the optical path between the polygon mirror 13 and the photosensitive drum 1030 is also called a scanning optical system. In the present embodiment, the scanning optical system includes a deflector side scanning lens 11a and an image plane side scanning lens 11b. Note that at least one folding mirror is disposed on at least one of the optical path between the deflector side scanning lens 11a and the image plane side scanning lens 11b and the optical path between the image plane side scanning lens 11b and the photosensitive drum 1030. May be.

  The scanning optical system converts the light beam deflected by the polygon mirror 13 into a light beam that scans the surface of the photosensitive drum 1030 at a constant moving speed in the main scanning direction, and condenses the light beam on the surface of the photosensitive drum 1030.

  FIG. 7 shows the positional relationship between main optical elements of the pre-deflector optical system and the scanning optical system. FIG. 8 shows an example of specific values (unit: mm) of the symbols d1 to d11 in FIG.

  Further, the direction of the light beam emitted from the cylindrical lens 17 and the light beam reflected toward the position of the image height 0 on the surface of the photosensitive drum 1030 (position p0 in FIG. 7) by the deflecting and reflecting surface of the polygon mirror 13. The angle formed with the traveling direction (θr in FIG. 7) is 60 degrees.

  Returning to FIG. 2, of the light beams deflected by the polygon mirror 13 and passed through the scanning optical system, a part of the light beam before the start of writing image information is detected as light for detection through the light detection mirror 19a. It enters the sensor 18a. The incident position of the detection light beam in the light detection sensor 18a moves in the main scanning corresponding direction (for convenience, the m direction) as the polygon mirror 13 rotates.

  As shown in FIG. 9 as an example, the light detection sensor 18a is disposed such that its light receiving surface is optically substantially parallel to the image plane (designed image plane). Accordingly, the detection light beam is equivalent to moving on the extension of the photosensitive drum 1030 in the main scanning direction, and the linearity (scanning constant velocity) of the scanning optical system with respect to the detection light beam is ensured. The moving speed of the detection light beam passing through the light detection sensor 18a can be made the same as the scanning speed in the image forming area of the photosensitive drum 1030, and the detection accuracy can be improved.

  In addition, the code | symbol 18a 'in FIG. 9 has shown the position of the optical detection sensor 18a when it assumes that there is no mirror 19a for optical detection.

  Further, the normal direction of the light receiving surface of the light detection sensor 18a is inclined with respect to the incident direction of the detection light flux so that the reflected light from the light reception surface of the light detection sensor 18a does not return to the light source unit 14 ( (See FIG. 9). Thereby, it can avoid that the reflected light in the light-receiving surface of the optical detection sensor 18a influences light quantity control.

As shown in FIG. 10 as an example, the light detection sensor 18a includes a light receiving element having two light receiving parts (first light receiving part 18 ₁ and second light receiving part 18 ₂ ), and the amount of light received from the light receiving element. An amplifier (AMP) 18 ₃ to which a signal (photoelectric conversion signal) is input, a comparator (CMP) that compares the output signal level of the amplifier 18 ₃ with a preset reference level Vs and outputs the comparison result 18 has _four. The output signal of the comparator 18 ₄ is supplied to the scanning control device 22.

  Each light receiving portion of the light receiving element has a different distance in the m direction depending on the position in the sub-scanning corresponding direction (for convenience, the s direction).

The first light receiving portion 18 ₁ has a rectangular light-receiving section as an example, it is arranged so that the longitudinal direction coincides with the direction s. That is, the two sides through which the detection light beam passes are both parallel to the s direction.

Second light receiving section 18 ₂ is a parallelogram light receiving unit as an example, it is arranged in the 1 + m side of the light receiving portion 18 _1. The second longitudinal direction of the light receiving portion 18 ₂ is inclined by an angle theta with respect to the first longitudinal direction of the light receiving portion 18 ₁ in the light-receiving surface (0 <θ <90 °) . That is, the two sides through which the detection light flux passes are both inclined with respect to the m direction.

In amplifier 18 _3, it is inverted and amplified input signal is performed. Therefore, as the amount of light received by the light receiving element is large, the output signal level of the amplifier 18 ₃ becomes low.

The reference level Vs, the detection light beam is set to a slightly higher level than the amplifier 18 _third output signal level (minimum value) when it is received by the light receiving element. Therefore, when any of the light receiving portion has received detection light beam, the judgment result of the comparator 18 ₄ is changed, the output signal of the comparator 18 ₄ changes accordingly.

The light detection sensor 18a is adjusted such that when the incident position of the light beam on the surface of the photosensitive drum 1030 is a designed position, the detection light beam passes through substantially the center of each light receiving unit (FIG. 11). (See (A)). Then, previously obtained at this time, as the time from the detection light beam is detected by the first light receiving portion 18 ₁ until detected by the second photodetector 18 _2, reference time Ts (see FIG. 11 (B)) It has been. For convenience, the movement path of the incident position of the detection light beam in the light detection sensor 18a at this time, that is, the design movement path is referred to as “path A”.

  By the way, due to an error in the mounting position when mounting each optical element in the housing 22 or due to aging, the optical path of the light beam toward the photosensitive drum 1030 is in the sub-scanning corresponding direction (here, May shift in the Z-axis direction). In this case, the detection light beam is also shifted in the sub-scanning corresponding direction (here, the s direction) with respect to the designed optical path, similarly to the light beam directed to the photosensitive drum 1030. As an example, as shown in FIG. 11C, the moving path of the incident position of the detection light beam in the light detection sensor 18a is also shifted in the sub-scanning corresponding direction with respect to the path A. For convenience, the movement route at this time is referred to as a route B.

The shift amount Δh (see FIG. 11C) of the movement path at this time can be obtained from the following equation (3). Here, [Delta] T is from the falling of the output signal of the comparator 18 ₄ is the difference between the time T and the reference time Ts until the next falling (see FIG. 11 (D)), V is the detection light beam It is a moving speed (scanning speed). This deviation amount Δh has a correlation with the deviation amount in the sub-scanning corresponding direction (here, the Z-axis direction) with respect to the designed optical path of the optical path of the light beam toward the photosensitive drum 1030.

  Δh = (V / tan θ) × ΔT (3)

Further, when the first light receiving portion 18 ₁ has received the detection light beam, the fall timing of the output signal of the comparator 18 ₄ is not affected by the incident position of detection light beams in the s direction (FIG. 11 (B ) And FIG. 11D). Therefore, when the first light receiving portion 18 ₁ has received the detection light beam, it is possible to obtain the timing of write start from the falling timing of the output signal of the comparator 18 _4.

  Returning to FIG. 2, out of the light beam deflected by the polygon mirror 13 and passed through the scanning optical system, a part of the light beam after completion of the writing of the image information is detected as a detection light beam through the light detection mirror 19b. The light enters the sensor 18b.

  The light detection mirror 19b and the light detection sensor 18b are arranged in the same positional relationship as the light detection mirror 19a and the light detection sensor 18a with respect to the detection light beam.

  The light detection sensor 18b outputs a signal similar to that of the light detection sensor 18a to the detection light beam. The output signal of the light detection sensor 18b is supplied to the scanning control device 22.

As shown in FIG. 12 as an example, the scanning control device 22 includes a CPU 210, a flash memory 211, a RAM 212, a liquid crystal element driving circuit 213, an IF (interface) 214, a pixel clock generation circuit 215, an image processing circuit 216, and a frame memory 217. , Line buffers 218 _{1 to} 218 ₄₀ , a write control circuit 219, a stepping motor drive circuit 220, and the like. Note that the arrows in FIG. 12 indicate the flow of typical signals and information, and do not represent the entire connection relationship of each block.

  The pixel clock generation circuit 215 generates a pixel clock signal.

  The frame memory 217 temporarily stores image data rasterized by the CPU 210 (hereinafter abbreviated as “raster data” for convenience).

The image processing circuit 216 reads the raster data stored in the frame memory 217, performs predetermined halftone processing, etc., then creates dot data (pixel data) for each light emitting unit, and corresponds to each light emitting unit. Output to the line buffers 218 ₁ to 218 ₄₀ .

Write control circuit 219, based on the output signal of the light detecting sensors 18a, when the first light receiving portion 18 ₁ has received the light beam for detecting synchronization, monitoring the fall in the output signal of the comparator 18 _4. When the falling edge is detected, the write start timing is obtained. Then, in accordance with the writing start timing, the dot data of each light emitting unit is read from the line buffers 218 _{1 to} 218 ₄₀ and superimposed on the pixel clock signal from the pixel clock generation circuit 215, and independent for each light emitting unit. Generate modulation data. The modulation data generated here is output to the drive circuit of the light source unit 14.

  The flash memory 211 stores various programs described by codes that can be decoded by the CPU 210.

  The RAM 212 is a working memory.

  The CPU 210 operates according to a program stored in the flash memory 211 and controls the entire optical scanning device 1010.

  For example, the CPU 210 obtains the deviation amount Δh based on the output signal of the light detection sensor 18a at every predetermined timing, and the positional deviation amount of the light beam on the surface of the photosensitive drum 1030 in the sub-scanning direction (hereinafter, for convenience). The voltage applied to the liquid crystal deflecting element 20 is determined so that the “sub-scanning deviation amount”) is substantially zero. Note that the shift amount Δh and the sub-scanning shift amount have a linear relationship as shown in FIG. 13 as an example, and the relationship between the sub-scanning shift amount and the applied voltage is obtained in advance and stored in the flash memory 211. Yes. Further, the coefficient k in FIG. 13 is a value unique to the apparatus and can be obtained in advance.

  In addition, when the sub-scanning deviation amount is ½ or more of the scanning line interval on the photosensitive drum 1030, the CPU 210 shifts the image data in a direction in which the sub-scanning deviation amount is reduced.

  Further, the CPU 210 obtains the deviation amount Δh based on the output signal of the light detection sensor 18b at every predetermined timing. Then, from the deviation amount Δh obtained from the output signal of the light detection sensor 18a and the deviation amount Δh obtained from the output signal of the light detection sensor 18b, the inclination information (inclination amount (angle) and inclination of the scanning line in the photosensitive drum 1030). Direction).

  The liquid crystal element driving circuit 215 applies the applied voltage determined by the CPU 210 to the liquid crystal deflecting element 20.

  The stepping motor drive circuit 220 outputs drive signals to the stepping motor 315 and the stepping motor 340, respectively, based on instructions from the CPU 210.

  An IF (interface) 214 is a communication interface that controls bidirectional communication with the printer control apparatus 1060. Image data from the host device is supplied via an IF (interface) 214.

  As shown in FIG. 14B, which is an AA cross-sectional view of FIG. 14A and FIG. 14A, the image side scanning lens 11b has a rib portion 306a formed on the surface on the −Z side. A rib portion 306b is formed on the + Z side surface.

The rib 306a is formed with _three protrusions (307a ₁ , 307a ₂ , 307a ₃ ) protruding in the −X direction. The rib portion 306b is formed with _three protrusions (307b ₁ , 307b ₂ , 307b ₃ ) that protrude in the −X direction.

  The image-side scanning lens 11b keeps its shape stable and does not deform the image-side scanning lens 11b even when stress is locally applied during tilt adjustment (maintaining the shape when the lens is assembled). ) As shown in FIG.

  A sheet metal member 301 on which the image plane side scanning lens 11b is held is shown in FIG. This sheet metal member 301 is a sheet member formed by sheet metal processing, and has a bottom plate 301a having a longitudinal direction in the Y-axis direction and two side plates (301b, 301c) facing each other with the bottom plate 301a interposed therebetween. ing.

The side plate 301b is a plate on the -X side, notch 311 ₂ notch 311 _first protrusion 307a ₁ of the image-side scanning lens 11b is engaged, the protrusion 307a ₂ are engaged, the protrusion 307a ₃ is notch 311 ₃ to be engaged is formed.

  On the bottom plate 301a, standing bent portions 310 each having an opening 313 are formed in the vicinity of the + Y side end portion and the −Y side end portion. The image plane side scanning lens 11b is placed on the upright bending portions 310 (see FIG. 18).

  In addition, three screw holes 312 are formed in the bottom plate 301a so as to correspond to the notches of the side plate 301b. Each screw hole 312 is formed at each position corresponding to the substantially central position of the image surface side scanning lens 11b in the X-axis direction when the image surface side scanning lens 11b is placed.

  Further, a protrusion 318 is formed at the + Y side end of the bottom plate 301a, and a notch 321 is formed at the −Y side end.

  The side plate 301b has two slits 314 corresponding to the openings 313 of the bottom plate 301a.

  As shown in FIGS. 16 to 19, the image side scanning lens 11 b is held on the sheet metal member 301 by three first plate springs 302 and two second plate springs 303. In FIG. 18, each side plate is not shown for easy understanding. FIG. 19 is a cross-sectional view taken along the line AA in FIG.

The first leaf spring 302 is used to sandwich the rib portion 306 a of the image-supply-side scanning lens 11 b and the sheet metal member 301. Here, the first plate spring 302, as shown in FIG. 17, a bottom plate 302 _1, and the side plate portion 302 ₂ of the -X side, the + X side and the side plate portion _3023, of the side plate portion 302 ₃ upper It has an upper plate portion 302 ₄ for extending in the -X direction from. Further, the side plate portion _3022, an opening is formed. Further, the bottom plate portion 302 _1, a circular opening 302 ₅ the adjustment screw 308 penetrates is formed.

Then, as shown in FIG. 19, the protrusion of the ribs 306a to the opening of the side plate portion ₃₀₂₂ is engaged, pressing the -Z direction is applied to the rib portion 306a of the + X side by the upper plate section 302 ₄ The

  The second leaf spring 303 is a clip-like leaf spring, which exerts a pressure in the −Z direction on the rib portion 306b of the image-supply-side scanning lens 11b, and + Z on the −Z side surface of the bottom plate 301a of the sheet metal member 301. By pressing the direction, the image plane side scanning lens 11b and the sheet metal member 301 are sandwiched. The plate portion on the −Z side of the second leaf spring 303 passes through the opening 313 from the outside and is inserted into the slit 304.

Furthermore, each screw hole 312 of the sheet metal member 301, adjusting screw 308 is threaded through the opening 302 ₅ of the first plate spring 302. The + Z side tip of the adjustment screw 308 abuts on the −Z side surface of the rib portion 306a of the image plane side scanning lens 11b. Therefore, by screwing the adjusting screw 308, it is possible to apply pressure in the + Z direction to the image plane side scanning lens 11b.

  In this case, since the pressing force by the adjusting screw 308 acting on the image surface side scanning lens 11b and the pressing force by the first leaf spring 302 act in opposite directions, the force acting on the image surface side scanning lens 11b is small. Adjustment is possible.

  For example, if the protruding amount of the adjusting screw 308 from the bottom plate 301a of the sheet metal member 301 is made smaller than the height of the upright bending portion 310, the image side scanning lens 11b can be warped so that its generatrix is convex downward. it can. On the contrary, when the protruding amount of the adjusting screw 308 is larger than the height of the upright bending portion 310, the image plane side scanning lens 11b can be warped so that its generatrix is convex upward. Therefore, by adjusting the protruding amount of the adjusting screw 308, the focal line of the image plane side scanning lens 11b is curved in the Z-axis direction, and the bending of the scanning line can be corrected. The adjustment screw 308 disposed between the center portion and the upright bending portion 310 can also correct M-type and W-type bends.

  The axis in the adjustment of the image side scanning lens 11b by each adjusting screw 308 is parallel to the optical axis of the image side scanning lens 11b.

  Adjustment of the image plane side scanning lens 11b by each adjustment screw 308 is performed by an operator at the time of shipment and maintenance.

  Incidentally, a resinous optical element is usually manufactured by injection molding using a mold from the viewpoint of moldability and manufacturing cost. In this case, the optical element after molding has non-uniform internal stress according to molding conditions (mold temperature, resin temperature, injection speed, cooling speed, etc.). Therefore, a resinous optical element that is long in the main scanning direction, such as an image side scanning lens, may be warped in the sub-scanning corresponding direction.

  In addition, since the image-side scanning lens is long and has low rigidity, it is likely to be deformed (warped) only by applying a slight stress.

  Further, the image plane side scanning lens is deformed by the difference in thermal expansion when a temperature difference occurs in the sub-scanning corresponding direction with a change in environmental temperature.

  When these deformations occur in the image side scanning lens, it is very difficult to maintain the scanning line state on the surface of the photosensitive drum at the time of shipment.

  Generally, linearity is corrected by curving the image side scanning lens in a direction to cancel the bending of the scanning line.

  In FIG. 20, as Comparative Example 1, in the optical scanning device disclosed in Patent Document 1, 25 ° C. is an initial temperature, and 25 ° C. → 50 ° C. → 25 ° C. → 10 ° C. → 25 ° C. → 50 ° C. → 25 A change in the amount of bending of the scanning line when the temperature is changed in degrees Celsius is shown. In this case, the amount of scan line bending greatly varied depending on the temperature, and a change of about 90 μm occurred between 10 ° C. and 50 ° C. Further, at 25 ° C., the scanning line bending amount is greatly different between when the temperature rises and when the temperature falls, and so-called hysteresis occurs. In the optical scanning device disclosed in Patent Document 1, a semi-cylindrical support portion is brought into contact with the center of the scanning lens in the longitudinal direction as a fulcrum for tilt adjustment. In such a configuration, the fitting portion of the stepping motor and the support plate and the central fulcrum function as a fixed end when the temperature fluctuates, and asymmetrical stress is generated with respect to the longitudinal direction of the scanning lens. Therefore, at 25 ° C., it is considered that hysteresis occurs because the way of generating stress differs between the support member and the scanning lens when the temperature rises and when the temperature falls.

  In FIG. 21, as Comparative Example 2, in the optical scanning device disclosed in Patent Document 3, 25 ° C. is an initial temperature, and 25 ° C. → 50 ° C. → 25 ° C. → 10 ° C. → 25 ° C. → 50 ° C. → 25 A change in the amount of bending of the scanning line when the temperature is changed in degrees Celsius is shown. Also in this case, hysteresis occurs in the scanning line bending amount due to the temperature change. The optical scanning device disclosed in Patent Document 3 has a configuration in which a scanning lens is sandwiched by support plates from above and below in the sub-scanning direction, and a plate spring that faces the adjustment screw is on the opposite side of the plate spring to the scanning lens. In order to arrange, the leaf spring will be crushed. When the leaf spring is crushed, it tends to cause permanent distortion, and the spring elastic force changes. Therefore, it is considered that hysteresis is generated when the stress strain of the leaf spring is relaxed due to a temperature change and cannot return to the initial state at 25 ° C.

  In FIG. 22, in the optical scanning device according to the present embodiment, 25 ° C. is an initial temperature, and the temperature is changed from 25 ° C. → 50 ° C. → 25 ° C. → 10 ° C. → 25 ° C. → 50 ° C. → 25 ° C. The change in the amount of scan line bending is shown. In this case, the change in the amount of bending of the scanning line is very small as compared with Comparative Example 1 and Comparative Example 2. Here, since the leaf spring is not crushed but deformed (elastically deformed) in the extending direction, it is considered that permanent deformation is unlikely to occur.

  Here, as an example, as shown in FIG. 23, the image plane side scanning lens 11 b, the sheet metal member 301, and the stepping motor 315 are accommodated in a case 341.

  The protruding portion 318 of the bottom plate 301a in the sheet metal member 301 is fitted into a guide provided in the case 341 and positioned. Further, the vicinity of the + Y side end portion of the bottom plate 301 a is supported by the support portion 320 and is urged in the −Z direction by a plate spring 326 whose one end is fixed to the case 341. That is, the vicinity of the + Y side end portion of the sheet metal member 301 is supported by the support portion 320 and the leaf spring 326. Hereinafter, for convenience, the portion supported by the support portion 320 and the leaf spring 326 is referred to as “fulcrum A”.

  As shown in FIG. 24A, a recess of the movable cylinder 316 is fitted into the notch 321 of the bottom plate 301a in the sheet metal member 301. As shown in FIG. 24B, which is a cross-sectional view taken along the line AA of FIG. 24A, the movable cylinder 316 has a screw hole in the Z-axis direction at the center.

  The vicinity of the −Y side end of the bottom plate 301 a in the sheet metal member 301 is biased in the −Z direction by a plate spring 326 whose one end is fixed to the case 341. That is, the vicinity of the −Y side end portion of the sheet metal member 301 is supported by the movable cylinder 316 and the leaf spring 326.

  Thus, the sheet metal member 301 is supported near both ends in the Y-axis direction. Therefore, when the image plane scanning lens 11b is held by the sheet metal member 301, the vicinity of both ends of the image plane scanning lens 11b is supported in the Y-axis direction.

  The stepping motor 315 has a feed screw formed at the tip of a shaft. The feed screw is screwed into the screw hole of the movable cylinder 316.

  Therefore, when the stepping motor 315 rotates, the movable cylinder 316 is displaced in the Z-axis direction (the height direction of the image plane side scanning lens 11b).

  Here, since the vicinity of the + Y side end portion of the bottom plate 301a in the sheet metal member 301 is supported, when the stepping motor 315 rotates, the image plane side scanning lens 11b rotates around an axis parallel to the optical axis and passing through the fulcrum A. Move. As a result, the bus line of the image plane side scanning lens 11b is inclined, and as a result, the scanning line on the surface of the photosensitive drum 1030 is inclined.

  Returning to FIG. 23, the end portion on the −Y side of the case 341 is supported by the support portion 342. Hereinafter, for convenience, the portion supported by the support portion 342 is referred to as “fulcrum B”.

  The stepping motor 340 is provided to rotate the case 341 around an axis parallel to the optical axis of the image-side scanning lens 11b and passing through the fulcrum B.

  FIG. 25 shows a state where the image plane side scanning lens 11b is rotated counterclockwise by the stepping motor 315. Note that FIG. 25 is simplified for easy understanding. In FIG. 25, symbol c is the center of the image plane side scanning lens 11b in the Y-axis direction.

  Here, as shown in FIG. 26, when the inclination of the image plane side scanning lens 11b is α and the distance from the fulcrum A to the center c of the image plane side scanning lens 11b is m with respect to the Y-axis direction, The change amount Δh is obtained by the following equation (4). In FIG. 26, the inclination angle of the image plane side scanning lens 11b is exaggerated for easy understanding.

Δh = m × α (4)

  FIG. 27 shows a state where the case 341 is rotated counterclockwise by the stepping motor 340. Note that FIG. 27 is simplified for easy understanding.

  Here, as shown in FIG. 28, if the inclination of the case 341 is β and the distance from the fulcrum B to the center c of the image plane side scanning lens 11b is m ′ with respect to the Y-axis direction, The change amount Δh ′ is obtained by the following equation (5). In FIG. 28, the inclination angle of the case 341 is exaggerated for easy understanding.

Δh ′ = m ′ × β (5)

  Therefore, if Δh = Δh ′, the image plane scanning lens 11b can be tilted by an angle (α + β) without changing the position of the center c of the image plane scanning lens 11b.

  The CPU 210 passes through the stepping motor drive circuit 220 so that Δh = Δh ′ and the inclination of the scanning line becomes 0 at every predetermined timing according to the inclination information of the scanning line obtained as described above. Each stepping motor is controlled to adjust the tilt of the image plane side scanning lens 11b.

  As is clear from the above description, in the optical scanning device 1010 according to the present embodiment, the polygon mirror 13 constitutes a deflector.

  Further, the stepping motor 315 and the support part 320 constitute a first adjustment mechanism, and the stepping motor 340 and the support part 342 constitute a second adjustment mechanism. A first axis is constituted by an axis parallel to the optical axis of the image plane side scanning lens 11b and passing through the fulcrum A, and a second axis is formed by an axis parallel to the optical axis of the image plane side scanning lens 11b and passing through the fulcrum B. Is configured.

  Further, a third adjustment mechanism is constituted by three adjustment screws.

  The light detection sensor 18a constitutes a first beam detection sensor, and the light detection sensor 18b constitutes a second beam detection sensor.

  The scanning control device 22 constitutes a control device.

  Further, at least a part of the processing according to the program by the CPU 210 may be configured by hardware, or all may be configured by hardware.

  As described above, according to the optical scanning device 1010 according to this embodiment, the light source unit 14, the polygon mirror 13 that deflects the light beam from the light source unit 14, and the image plane in which both ends are supported by the support member. A scanning optical system that includes the side scanning lens 11b and condenses the light beam deflected by the polygon mirror 13 on the surface of the photosensitive drum 1030, and a plurality of adjustment mechanisms for adjusting the inclination of the image side scanning lens 11b. It has.

  Each of the plurality of adjustment mechanisms has an adjustment axis parallel to the optical axis of the image plane side scanning lens 11b, and the adjustment axes are provided at different positions in the main scanning direction.

  In this case, the inclination of the image plane side scanning lens 11b can be adjusted without displacing the center of the image plane side scanning lens 11b. That is, the inclination of the image plane scanning lens 11b can be adjusted by rotating the image plane scanning lens 11b around an axis passing through the center of the image plane scanning lens 11b.

  Therefore, the deterioration of the light flux at the image plane side scanning lens 11b is suppressed, and it becomes possible to perform stable and highly accurate optical scanning.

  Further, since the temperature hysteresis of the scan line bending amount is small, if the adjustment screws 308 are adjusted at the time of shipment, there is no need to adjust again even if the environmental temperature varies on the user side.

  Further, the CPU 210 determines the applied voltage of the liquid crystal deflecting element 20 so that the sub-scanning deviation amount becomes almost zero at every predetermined timing, and applies it to the liquid crystal deflecting element 20 via the liquid crystal element driving circuit 215. Yes. Therefore, the sub-scanning deviation amount can be stably reduced.

  Further, since the light source unit 14 has the two-dimensional array 100, a plurality of scans can be performed simultaneously.

  Further, since the laser printer 1000 according to the present embodiment includes the optical scanning device 1010, it is possible to stably form a high-quality image as a result.

  Furthermore, since the optical scanning device 1010 includes the light source unit 14 having the two-dimensional array 100, an image can be formed at high speed. In addition, the density of the formed image can be increased.

  In addition, by connecting the laser printer 1000 to an electronic arithmetic device (computer or the like), an image information communication system (facsimile or the like), etc. via a network, a single image forming apparatus can output from a plurality of devices. An information processing system that can be processed can be formed. In addition, if multiple image forming devices are connected to the network, the status of each image forming device (the degree of job congestion, whether the power is on, whether it is broken, etc.) can be known from each output request. The image forming apparatus having the best state (most suitable for the user's request) can be selected and image formation can be performed.

  In the above-described embodiment, the case where the adjustment screw 308 is provided at three positions has been described. However, when there is no need to correct the bending of the M-type or the W-type, the adjustment screw 308 is only provided at one central position. May be provided.

  In the above embodiment, the case where m ≠ m ′ has been described, but a case where m = m ′ may be used instead of the case 341. In this case, when the inclination angle of the image plane side scanning lens 11b necessary for correcting the inclination of the scanning line is γ, if α = β = γ / 2, the feeding amount of each stepping motor can be made equal. . Furthermore, in this case, the adjustment allowance can be up to the maximum feed amount of each stepping motor.

  If α = β, the space for adjustment in the sub-scanning corresponding direction required by the adjustment mechanism including each stepping motor can be reduced.

  In the above embodiment, the case where the positions of the fulcrum A and the fulcrum B in the Z-axis direction are different from each other is described. However, instead of the case 341, the positions of the fulcrum A and the fulcrum B in the Z-axis direction A case that coincides with the center line of the lens 11b in the Z-axis direction may be used. In this case, even if the inclination adjustment of the image plane side scanning lens 11b is performed, the change in the center position of the image plane side scanning lens 11b can be suppressed in both the main scanning corresponding direction and the sub scanning corresponding direction.

  In the above embodiment, the pixel clock generation circuit 215 scans the light beam between the light detection sensor 18a and the light detection sensor 18b from the output signal of the light detection sensor 18a and the output signal of the light detection sensor 18b. It is also possible to obtain the time required for this and reset the reference frequency of the pixel clock signal so that a preset number of pulses fit within that time.

Further, in the above embodiment, the first shape of the light-receiving portion 18 ₁ has been described for the case of rectangular, it is not limited thereto, two sides detection light beam to pass through in parallel shape s direction I need it.

In the above embodiment, the second the shape of the light receiving portion 18 ₂ has been described for the case of the parallelogram, is not limited thereto, two sides the light flux for detection to pass through to the m direction And any shape that is inclined.

  Moreover, although the said embodiment demonstrated the case where the light source unit 14 had 40 light emission parts, it is not limited to this.

  Moreover, in the said embodiment, it may replace with the said liquid-crystal deflection | deviation element 20, and may use the non-parallel plate which can be rotated, or a galvanometer mirror. In short, it is only necessary that the scanning control device 22 can deflect the incident light with respect to the sub-scanning corresponding direction so that the sub-scanning deviation amount becomes substantially zero.

  In the above embodiment, instead of shifting the image data, the light emitting unit to be driven may be changed to another light emitting unit at a different position with respect to the sub-scanning corresponding direction.

  FIG. 29 shows a case where the image plane side scanning lens 11 b is held by a sheet metal member 401 different from the sheet metal member 301, and the sheet metal member 401 is placed on the base member 402. In this case, a driving mechanism 403 that has a fulcrum on one side in the main scanning direction with respect to the optical axis of the image surface side scanning lens 11b and tilts the base member 402 together with the sheet metal member 401, and an image surface side scanning lens. A driving mechanism 404 having a fulcrum on the other side in the main scanning direction with respect to the optical axis 11b and tilting the sheet metal member 401 with respect to the base member 402 is provided.

  In this case, for example, as shown in FIGS. 30A to 30D, first, the sheet metal member 401 is moved so that the right end of the image-side scanning lens 11 b rises by L using the drive mechanism 404. When the base member 402 and the sheet metal member 401 are tilted so that the left end of the image plane side scanning lens 11b is lowered by L using the drive mechanism 403, the center in the longitudinal direction of the image plane side scanning lens 11b is obtained. The tilt of the image plane side scanning lens 11b can be adjusted without displacing the position in the sub scanning direction.

  At this time, since both ends of the sheet metal member 401 are supported, the free end side is influenced by vibration as in the conventional method in which the rotation adjustment fulcrum is at the center of the image plane side scanning lens 11b. The scanning line is not bent.

  As shown in FIG. 31A as an example, each drive mechanism includes a contact member 405 that is in contact with a drive object, and a drive device 406 that moves the contact member 405 in the sub-scanning direction. As shown in FIG. 31B, the contact between the contact member 405 and the driving object is a line contact parallel to the optical axis of the image-side scanning lens 11b. In this case, it is possible to prevent the image plane side scanning lens 11b from falling in the optical axis direction.

  In addition, when the image plane side scanning lens 11b is provided with a plurality of positioning reference setting parts in the sub-scanning direction in the optical axis direction, or when it has a long shape in the sub-scanning direction, an example is given. As shown in FIG. 32, the contact between the contact member 405 and the driven object may be a point contact. In this case, it is possible to prevent the image plane side scanning lens 11b from falling in the optical axis direction by applying pressure to the reference setting portion and pressing it against the abutting portion.

  By the way, when the contact between the contact member and the driving object is a line contact, there is an advantage that the resistance in the reference setting unit is small, and the movement of the image plane side scanning lens 11b during the tilt adjustment is smooth. If the angle of the image is inclined, the image plane side scanning lens 11b may also be inclined in the optical axis direction. On the other hand, when the contact between the contact member and the driving object is a point contact, the image plane side scanning lens 11b does not tilt in the optical axis direction, but the resistance at the reference setting unit is large, and the image plane during tilt adjustment is large. The movement of the side scanning lens 11b is not smooth.

  In FIG. 33, in place of the sheet metal member 301, the image plane side scanning lens 11b is positioned at both ends in the main scanning direction so that the positions in the sub scanning direction coincide with the center of the image plane side scanning lens 11b. The case where it hold | maintains at the sheet-metal member 411 which has the extended surface extended in this is shown. Each extending surface of the sheet metal member 411 is biased in the sub-scanning direction by the spring 413 of the base member 412. Each extending surface of the sheet metal member 411 is further supported by the link member 415. In this case, the link member 415 is arranged around an axis that is parallel to the optical axis of the image plane side scanning lens 11b, passes through the center of the link member 415, and the position in the main scanning direction coincides with the center of the image plane side scanning lens 11b. Is provided with a drive mechanism 414 for rotating the. Here, the link member 415 and the drive mechanism 414 are pin-coupled. The base member 412 has high rigidity and is fixed to the housing 22.

  In this case, if the link member 415 is tilted using the drive mechanism 414, as shown in FIG. 34 as an example, the position in the sub-scanning direction at the center in the longitudinal direction of the image-side scanning lens 11b is not displaced. The inclination of the image plane side scanning lens 11b can be adjusted. Even if the link member 415 is inclined using the drive mechanism 414, the base member 412 remains unchanged.

  Also in this case, since both ends of the sheet metal member 411 are supported, the free end side is affected by vibration as in the conventional method in which the rotation adjustment fulcrum is at the center of the image plane side scanning lens 11b. No scanning or bending of the scanning line occurs.

  Further, in this case, the number of drive mechanisms can be one.

  FIG. 35 shows a case where the image plane side scanning lens 11b is held by a sheet metal member 421 different from the sheet metal member 301 and both end portions in the main scanning direction of the sheet metal member 421 are fixed to the base member 422. ing. In this case, a drive mechanism 423 is provided which has a fulcrum whose position in the main scanning direction coincides with the center of the image plane side scanning lens 11b and tilts the base member 422.

  In this case, when the base member 422 is tilted using the drive mechanism 424, as shown in FIG. 36 as an example, the position in the sub-scanning direction of the center in the longitudinal direction of the image-side scanning lens 11b is not displaced. The inclination of the image plane side scanning lens 11b can be adjusted.

  Further, in this case, since the base member 422 has high rigidity, even if there is a rotation adjustment fulcrum in the center of the main scanning direction, the free end side is affected by vibration or scanning line bending occurs. There is nothing.

  Further, in this case, the number of drive mechanisms can be one.

  In the above embodiment, the case of the laser printer 1000 as the image forming apparatus has been described. However, the present invention is not limited to this. In short, an image forming apparatus including the optical scanning device 1010 can stably form a high-quality image as a result.

  For example, an image forming apparatus that directly irradiates laser light onto a medium (for example, paper) that develops color with laser light may be used.

  Further, an image forming apparatus using a silver salt film as the image carrier may be used. In this case, a latent image is formed on the silver salt film by optical scanning, and this latent image can be visualized by a process equivalent to a developing process in a normal silver salt photographic process. Then, it can be transferred to photographic paper by a process equivalent to a printing process in a normal silver salt photographic process. Such an image forming apparatus can be implemented as an optical plate making apparatus or an optical drawing apparatus that draws a CT scan image or the like.

  For example, as shown in FIG. 37, a color printer 2000 including a plurality of photosensitive drums may be used.

  The color printer 2000 is a tandem multicolor printer that forms a full-color image by superimposing four colors (black, cyan, magenta, and yellow), and includes an optical scanning device 2010, four photosensitive drums (2030a). , 2030b, 2030c, 2030d), four cleaning units (2031a, 2031b, 2031c, 2031d), four charging chargers (2032a, 2032b, 2032c, 2032d), and four developing rollers (2033a, 2033b, 2033c, 2033d), four toner cartridges (2034a, 2034b, 2034c, 2034d), transfer belt 2040, fixing roller 2050, paper feed roller 2054, registration roller pair 2056, paper discharge roller 2058, paper feed tray 2060, paper discharge. Ray 2070, and includes a communication controller 2080, and a printer controller 2090 for totally controlling the above elements.

As shown in FIG. 38 and FIG. 39 as an example, the optical scanning device 2010 includes two light source units (2200a, 2200b), two aperture plates (2201a, 2201b), and two light beam splitting prisms (2202a, 2202b), polygon mirror 2104, four liquid crystal deflecting elements (2203a, 2203b, 2203c, 2203d), four cylinder lenses (2204a, 2204b, 2204c, 2204d), four fθ lenses (2105a, 2105b, 2105c, 2105d), 8 scanning mirrors (2106a, 2106b, 2106c, 2106d, 2108a, 2108b, 2108c, 2108d), 4 toroidal lenses (2107a, 2107b, 2107c, 2107d), 8 light detection sensors (2205a) ₁ , 22 05b ₁ , 2205c ₁ , 2205d ₁ , 2205a ₂ , 2205b ₂ , 2205c ₂ , 2205d ₂ ), 8 light detection mirrors (2207a ₁ , 2207b ₁ , 2207c ₁ , 2207d ₁ , 2207a ₂ , 2207b ₂ , 2207c ₂ 2207d ₂ ), and a scanning control device (not shown). These are assembled at predetermined positions in the housing 2300 (not shown in FIG. 38, see FIG. 39). In FIG. 39, only a part of the light detection sensor and the light detection mirror is visible.

Photosensitive drum 2030a, charging charger 2032a, developing roller 2033a, toner cartridge 2034a, cleaning unit 2031a, liquid crystal deflection element 2203a, cylinder lens 2204a, fθ lens 2105a, scanning mirror 2106a, toroidal lens 2107a, scanning mirror 2108a, light detection The sensor 2205a ₁ , the light detection sensor 2205a ₂ , the light detection mirror 2207a ₁ , and the light detection mirror 2207a ₂ are used as a set and form an image forming station (hereinafter also referred to as “K station” for convenience) that forms a black image. ).

Photosensitive drum 2030b, charging charger 2032b, developing roller 2033b, toner cartridge 2034b, cleaning unit 2031b, liquid crystal deflection element 2203b, cylinder lens 2204b, fθ lens 2105b, scanning mirror 2106b, toroidal lens 2107b, scanning mirror 2108b, light detection The sensor 2205b ₁ , the light detection sensor 2205b ₂ , the light detection mirror 2207b ₁ , and the light detection mirror 2207b ₂ are used as a set, and are also referred to as an “C station” for convenience in forming a cyan image. ).

Photosensitive drum 2030c, charging charger 2032c, developing roller 2033c, toner cartridge 2034c, cleaning unit 2031c, liquid crystal deflecting element 2203c, cylinder lens 2204c, fθ lens 2105c, scanning mirror 2106c, toroidal lens 2107c, scanning mirror 2108c, light detection The sensor 2205c ₁ , the light detection sensor 2205c ₂ , the light detection mirror 2207c ₁ , and the light detection mirror 2207c ₂ are used as a set, and are also referred to as an “M station” for convenience in forming a magenta image. ).

Photosensitive drum 2030d, charging charger 2032d, developing roller 2033d, toner cartridge 2034d, cleaning unit 2031d, liquid crystal deflecting element 2203d, cylinder lens 2204d, fθ lens 2105d, scanning mirror 2106d, toroidal lens 2107d, scanning mirror 2108d, light detection The sensor 2205d ₁ , the light detection sensor 2205d ₂ , the light detection mirror 2207d ₁ , and the light detection mirror 2207d ₂ are used as a set, and are also referred to as “Y station” for convenience in forming a yellow image. ).

  Each light source unit has the same configuration as the light source unit 14. Here, each light source unit is disposed in the vicinity of the + Y side end of the housing 2300.

  The light beam emitted from the light source unit 2200a and passing through the opening of the aperture plate 2201a is split into a light beam for the K station and a light beam for the C station by the light beam splitting prism 2202a. The light beam emitted from the light source unit 2200b and having passed through the opening of the aperture plate 2201b is split into a light beam for the M station and a light beam for the Y station by the light beam splitting prism 2202b.

  Each of the divided light beams enters a common polygon mirror 2104 via a corresponding liquid crystal deflecting element and cylinder lens. Each light beam deflected by the polygon mirror 2104 irradiates the corresponding photosensitive drum through the corresponding fθ lens, scanning mirror, and toroidal lens.

  Each of the light detection sensors is the same sensor as the light detection sensor 18a.

Part of the light beam before the start of the writing that has been reflected by the scanning mirror 2108a is reflected by the light detection mirror 2207A _1, incident as the detection light beam to the optical detection sensor 2205a _1. Also, part of the light beam after completion of writing reflected by the scanning mirror 2108a is reflected by the light detection mirror 2207A _2, enters as the detection light beam to the optical detection sensor 2205a _2.

Part of the light beam before the start of the writing that has been reflected by the scanning mirror 2108b is reflected by the light detection mirror 2207B _1, incident as the detection light beam to the optical sensor 2205b _1. Also, part of the light beam after completion of writing reflected by the scanning mirror 2108b is reflected by the light detection mirror 2207B _2, enters as the detection light beam to the optical sensor 2205b _2.

Part of the light beam before the start of the writing that has been reflected by the scanning mirror 2108c is reflected by the light detection mirror 2207C _1, incident as the detection light beam to the optical sensor 2205c _1. Also, part of the light beam after completion of writing reflected by the scanning mirror 2108c is reflected by the light detection mirror 2207C _2, enters as the detection light beam to the optical detection sensor 2205c _2.

Part of the light beam before the start of the writing that has been reflected by the scanning mirror 2108d is reflected by the light detection mirror 2207D _1, incident as the detection light beam to the optical sensor 2205d _1. Also, part of the light beam after completion of writing reflected by the scanning mirror 2108d is reflected by the light detection mirror 2207D _2, enters as the detection light beam to the optical detection sensor 2205d _2.

  Each toroidal lens is supported by supporting members at both ends in the same manner as the image plane side scanning lens 11b in the above embodiment. Each toroidal lens is provided with a plurality of adjustment mechanisms similar to those in the above embodiment.

  The scanning control device detects the writing start timing on each photosensitive drum in the same manner as the scanning control device 22.

  Similarly to the scanning control device 22, the scanning control device acquires sub-scanning deviation information and scanning line inclination information on each photosensitive drum based on the output signals of the respective light detection sensors.

  Then, the scanning control device applies a voltage to each liquid crystal deflecting element so that the sub-scanning deviation amount in each photoconductive drum becomes substantially zero.

  In addition, the scanning control device controls a plurality of adjustment mechanisms according to the acquired inclination information of the scanning line in each photosensitive drum, so that the state of the scanning line is the same as the state at the time of shipment. Adjust the tilt. At this time, with reference to the K station, the tilt adjustment of the toroidal lens in the other image forming station is performed so that the inclination information of the scanning line in the K station matches the inclination information of the scanning line in the other image forming station. You can go.

  Similarly to the scanning control device 22, the scanning control device corresponds to the direction in which the sub-scanning deviation is canceled when the sub-scanning deviation amount is ½ or more of the scanning line interval on the photosensitive drum. Shift image data.

  Therefore, the optical scanning device 2010 can obtain the same effect as the optical scanning device 1010.

  Since the color printer 2000 includes the optical scanning device 2010, the same effect as the laser printer 1000 can be obtained. In addition, color misregistration of the image can be reduced.

  In this color printer 2000, an optical scanning device may be provided for each color, or may be provided for every two colors.

  As described above, the optical scanning device of the present invention is suitable for performing stable and highly accurate optical scanning. The image forming apparatus of the present invention is suitable for stably forming a high-quality image.

It is a figure for demonstrating schematic structure of the laser printer which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the optical scanning device in FIG. It is a figure for demonstrating the two-dimensional array contained in a light source unit. 4A and 4B are diagrams for explaining the liquid crystal deflection element. It is a figure for demonstrating the optical surface shape of a deflector side scanning lens. It is a figure for demonstrating the optical surface shape of an image surface side scanning lens. It is a figure for demonstrating the positional relationship of the main optical elements in an optical scanning device. It is a figure for demonstrating the specific example in FIG. It is a figure for demonstrating the surface substantially parallel to an image surface optically. It is a figure for demonstrating schematic structure of a photon detection sensor. 11A to 11D are diagrams for explaining the operation of the light detection sensor of FIG. It is a block diagram for demonstrating the structure of a scanning control apparatus. It is a figure for demonstrating the relationship between subscanning deviation | shift amount and (DELTA) h. FIGS. 14A and 14B are diagrams for explaining the image plane side scanning lens. It is a figure for demonstrating the sheet-metal member holding an image surface side scanning lens. It is a figure for demonstrating the member used when hold | maintaining an image surface side scanning lens to a sheet-metal member. It is a figure for demonstrating a leaf | plate spring. It is a figure for demonstrating the state by which the image surface side scanning lens is hold | maintained at the sheet-metal member. It is AA sectional drawing of FIG. It is a figure for demonstrating the relationship between the scanning line bending amount and temperature history in the comparative example 1. FIG. It is a figure for demonstrating the relationship between the amount of scanning line bends, and temperature history in comparative example 2. FIG. It is a figure for demonstrating the relationship between the scanning line bending amount and temperature history in this embodiment. It is a figure for demonstrating a some adjustment mechanism. FIGS. 24A and 24B are views for explaining the fitting of the notch portion of the bottom plate and the movable cylinder. FIG. 6 is a diagram (No. 1) for explaining tilt adjustment of an image plane side scanning lens. FIG. 6 is a diagram (No. 2) for explaining the tilt adjustment of the image plane side scanning lens. FIG. 10 is a third diagram for explaining the tilt adjustment of the image plane side scanning lens; FIG. 14 is a diagram (No. 4) for explaining the inclination adjustment of the image plane side scanning lens. It is a figure for demonstrating the modification 1 of the inclination adjustment mechanism of an image surface side scanning lens. 30A to 30D are diagrams for explaining tilt adjustment using the tilt adjustment mechanism of the first modification. FIG. 31A and FIG. 31B are diagrams for explaining the case where the contact between the contact member and the driving object is a line contact. It is a figure for demonstrating the case where the contact of a contact member and a drive target object is a point contact. It is FIG. (1) for demonstrating the modification 2 of the inclination adjustment mechanism of an image surface side scanning lens. It is FIG. (2) for demonstrating the modification 2 of the inclination adjustment mechanism of an image surface side scanning lens. It is FIG. (1) for demonstrating the modification 3 of the inclination adjustment mechanism of an image surface side scanning lens. It is FIG. (2) for demonstrating the modification 3 of the inclination adjustment mechanism of an image surface side scanning lens. 1 is a diagram illustrating a schematic configuration of a color printer. It is a perspective view which shows a part of optical scanning device in FIG. It is a side view which shows a part of optical scanning device in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11a ... Deflector side scanning lens (a part of scanning optical system), 11b ... Image surface side scanning lens (scanning lens), 13 ... Polygon mirror (deflector), 14 ... Light source unit, 18a ... Light detection sensor (1st 18b ... light detection sensor (second beam detection sensor), 22 ... scanning control device (control device), 100 ... two-dimensional array, 308 ... adjustment screw (third adjustment mechanism), 315 ... Stepping motor (part of the first adjustment mechanism), 320 ... support part (part of the first adjustment mechanism), 340 ... stepping motor (part of the second adjustment mechanism), 342 ... support part (second Part of adjusting mechanism), 401 ... sheet metal member (holding member), 402 ... base member, 403 ... driving mechanism, 404 ... driving mechanism, 405 ... contact member, 406 ... driving device, 411 ... sheet metal member (holding member). , 41 ... base member, 413 ... spring (elastic member), 414 ... drive mechanism, 415 ... link member, 421 ... sheet metal member (holding member), 422 ... base member, 423 ... drive mechanism, 1000 ... laser printer (image forming apparatus) DESCRIPTION OF SYMBOLS 1010 ... Optical scanning apparatus, 1030 ... Photosensitive drum (image carrier), 1050 ... Communication control apparatus (communication apparatus), 2000 ... Printer (image forming apparatus), 2010 ... Optical scanning apparatus, 2030a, 2030b, 2030c, 2030d ... photosensitive drum (image carrier), 2080 ... communication control device (communication device), 2104 ... polygon mirror (deflector), 2105a to 2105d ... fθ lens (part of scanning optical system), 2107a to 2107d ... toroidal lens (scanning lens), 2200a ... light source unit, 2200 b ... light source unit, 2205a ₁ ~ 205d 1 _... light detection sensor (first beam detecting _sensor) 2205a 2 _~2205d 2 _... light detection sensor (second beam sensor).

Claims (13)

An optical scanning device that scans a surface to be scanned in a main scanning direction with a light beam,
With a light source;
A deflector for deflecting a light beam from the light source;
Includes a run査lens, a scanning optical system for focusing the light beam deflected by said deflector on the surface to be scanned;
First and second adjustment mechanisms for adjusting the tilt of the scanning lens;
The first adjustment mechanism rotates a holding member that holds the scanning lens around a first axis that is parallel to the optical axis of the scanning lens, with an end portion on one side of the holding member in the main scanning direction serving as a fulcrum. Move
The second adjustment mechanism is configured to support a support body that supports an end portion of the holding member on one side in the main scanning direction from one side in a direction orthogonal to both the first axial direction and the main scanning direction. Rotate around a second axis parallel to the optical axis with the other end of the body in the main scanning direction as a fulcrum;
An end portion on one side of the holding member in the main scanning direction is pressed against the support from the other side in a direction orthogonal to both the first axial direction and the main scanning direction by a first leaf spring,
The other end of the support in the main scanning direction is supported by the support from one side in a direction perpendicular to both the second axial direction and the main scanning direction, and the second leaf spring supports the first end. An optical scanning device pressed against the support from the other side in a direction orthogonal to both the axial direction and the main scanning direction . In the main scanning direction, and the distance from the optical axis of the scanning lens to the first axis, the distance from the optical axis of the scanning lens to the second axis, according to claim 1, wherein the equal Optical scanning device. The optical scanning device according to claim 2 , wherein an adjustment amount by the first adjustment mechanism is equal to an adjustment amount by the second adjustment mechanism. Wherein the amount of tilting of the scanning lens according to the first adjusting mechanism, the inclination amount of the scanning lens according to the second adjusting mechanism includes an optical scanning apparatus according to claim 1, wherein the equivalent. 2. The optical scanning device according to claim 1 , wherein the first axis, the second axis, and the optical axis of the scanning lens are all in the same position in the sub-scanning direction. Wherein the run査lens, an optical scanning apparatus according to any one of claims 1-5, characterized in that it comprises a third adjusting mechanism for applying a pressing in the sub-scanning direction. The optical scanning device according to claim 6 , wherein the third adjusting mechanism applies the pressing to a plurality of locations of the scanning lens. A first beam detection sensor that is deflected by the deflector and that receives a light beam before starting writing through the scanning lens and outputs a signal including information on deviation from a reference position in the sub-scanning direction;
A second beam detection sensor which is deflected by the deflector and receives a light beam after writing through the scanning lens and outputs a signal including deviation information from a reference position in the sub-scanning direction;
A control device that obtains inclination information of a scanning line on the surface to be scanned based on output signals of the first and second beam detection sensors and controls the plurality of adjusting mechanisms according to the inclination information of the scanning line. When; optical scanning apparatus according to any one of claims 1 to 7, further comprising a. Said light source, an optical scanning apparatus according to any one of claims 1-8, characterized in that it comprises a plurality of light emitting portions that are two-dimensionally arranged. It said light source, an optical scanning apparatus of any one of claim 1 to 9, characterized in that it comprises a surface-emitting laser of vertical cavity. At least one image carrier;
An image forming apparatus comprising: at least one optical scanning device according to any one of claims 1 to 10 that scans the at least one image carrier with a light beam modulated according to image information. The image forming apparatus according to claim 11 , wherein the image information is multicolor image information. The image forming apparatus according to claim 11 , further comprising a communication device that communicates various information including the image information with an external device via a network.

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