JP2003287700A - Scanning optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scanning optical device which can adjust a return mirror with high precision and keep the linearity of automatic adjustment of a scanning line tilt excellent, has very small color slurring, and is suitable to a color image forming device using a plurality of photosensitive bodies. <P>SOLUTION: The scanning optical device has a laser light source, a deflecting means which deflects the laser luminous flux emitted by the laser light source, one or more imaging means which scan an image carrier with the laser luminous flux deflected by the deflecting means to form an image, and a reflector which is arranged before one imaging means or between a plurality of imaging means and also has a reflector adjusting mechanism which is provided to the reflector and adjusts the direction of the laser luminous flux; and the reflector adjusting mechanism has an adjustment base which displaces one lengthwise end of the reflector along the optical axis and a link included in the adjustment base and rotates the reflector round an axis nearly parallel to the length by rotating the link. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning optical device used in a color image forming apparatus using a plurality of photoconductors.

[0002]

2. Description of the Related Art The applicant of the present invention has previously disclosed Japanese Patent Laid-Open No. 11-3268.
04, proposes a scanning optical device used in a color image forming apparatus using a plurality of photoconductors. This is a very effective one that uses a diffractive optical element and adjusts the color shift for each color by displacing or rotating the diffractive optical element. Further, the applicant of the present application has disclosed in Japanese Patent Application Laid-Open No. 2000-100135 that a folding mirror is arranged between a plurality of scanning lenses to make the scanning optical device compact, and the folding mirror is adjusted so that the light flux incident on the diffractive optical element is adjusted. By making the diffractive optical element pass through substantially the center in the main scanning direction to prevent spot collapse and the like, a scanning optical device optimal for a color image forming apparatus using a plurality of photoconductors is proposed.

[0003]

The invention according to the present application is
The present invention is to further develop the scanning optical device used in the color image forming apparatus proposed by the above-mentioned prior application and propose a more optimal configuration.

Specifically, 1. How to adjust the folding mirror with high precision. 2. Automatic adjustment mechanism of scan line inclination that can obtain high linearity. It is a thing that proposes.

[0005]

[Means for Solving the Problems] To achieve the above object,
1st invention which concerns on this application WHEREIN: The laser light source, the deflection means which deflect | deviates the laser light flux emitted from this laser light source, and the laser light flux deflected by this deflection means scans and forms an image on an image carrier 1 or A reflecting mirror having a plurality of image forming means and a reflecting mirror arranged in front of the one image forming means or between the plurality of image forming means and adjusting a direction of a laser beam provided on the reflecting mirror. In the scanning optical device having an adjusting mechanism, the reflecting mirror adjusting mechanism includes an adjusting table for displacing one end of the reflecting mirror in the longitudinal direction in the optical axis direction, and a link contained in the adjusting table. It is a mechanism for rotating the reflecting mirror about an axis substantially parallel to the longitudinal direction by rotating the link.

According to the invention, one of the imaging means is
It is characterized by having a registration adjusting mechanism for adjusting the inclination of the scanning line on the image carrier by automatically rotating at least about an axis substantially parallel to the optical axis.

A second aspect of the present invention is directed to a laser light source, a deflecting means for deflecting a laser light flux emitted from the laser light source, and a laser light flux deflected by the deflecting means for scanning and combining the image carrier. One or more imaging means for imaging;
A reflecting mirror disposed in front of the one image forming unit or between the plurality of image forming units and at least a scanning line on the image carrier by displacing or rotating one of the image forming units. And a registration adjusting mechanism for adjusting the inclination, wherein the registration adjusting mechanism,
It is characterized in that it includes a mechanism for adjusting the inclination of the scanning line on the image carrier by automatically rotating one of the image forming means about an axis substantially parallel to the optical axis.

Further, in the first and second aspects of the present application, the registration adjusting mechanism is a motor, a cam gear which rotates following the rotation of the motor and has an inclined cam surface, and a cam gear of the cam gear. A movable table that can move in the sub-scanning direction following the rotation, a biasing means that biases the movable table to the cam gear, a support plate that supports one of the image forming means, and the movable table. A support and a connecting means for connecting one end in the longitudinal direction of the support plate, and the support plate is substantially parallel to the optical axis with one end on the opposite side of the connecting means as a center in association with the movement of the movable table. It is also characterized by rotating around a different axis.

In the first and second inventions of the present application, the movable table has a sliding hole substantially parallel to the sub-scanning direction, and the sliding hole is included in the registration adjusting mechanism. Is inserted into a guide shaft that projects substantially parallel to the sub-scanning direction from the housing, the movable table is movable along the guide shaft, and is arranged substantially parallel to the biasing means.
It is also characterized in that it has a backlash removing means for tilting the movable table to eliminate backlash due to the engagement with the guide shaft.

Further, the connecting means has a substantially cylindrical bearing portion having a notch in a part thereof, and the movable table projects substantially parallel to the main scanning direction and has a shaft portion thicker than the inner diameter of the bearing portion. A shaft portion protruding from the movable table is inserted into the bearing portion.

[0011]

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view showing a scanning optical device according to this embodiment. In the figure, 1 is a light source unit, 2 is a cylindrical lens, 3 is an optical diaphragm, 4 is a polygon mirror, 5 is a scanner motor, 6 is a toric lens, and 7
Is a folding mirror, 8 is a diffractive optical element, 9 is a synchronous detection lens, 10 is a synchronous detection mirror, 11 is a synchronous detection sensor unit, 12 is a mirror adjustment unit, 13 is a tilt adjustment unit, and 14 is the parts and units described above. An optical box 15 is a photoconductor.

The light source unit 1 emits a laser light flux L1 which is a parallel light flux. The laser light flux L1 is condensed only in the sub-scanning direction by the cylindrical lens 2, and the light flux width is limited by the optical diaphragm 3 and reflected by the polygon mirror 4. An image is formed on the surface as a long line image in the main scanning direction. The polygon mirror 4 is rotationally driven by the scanner motor 5 to deflect the laser light flux L1, passes through the toric lens 6, and is deflected by the folding mirror 7 to change its direction.
And then imaged as scanning lines 16 on the photoconductor 15 to form an electrostatic latent image. Also, the polygon mirror 4
A part of the laser light flux deflected by is passed through the synchronization detection lens 9 and the synchronization detection mirror 10 to the synchronization detection sensor unit 11 and used for detecting the writing position in the main scanning direction. Further, the folding mirror 7 is displaced or rotated to adjust the height and inclination of the laser beam incident on the diffractive optical element 8.

Next, a color image forming apparatus equipped with the scanning optical apparatus of this embodiment will be described with reference to FIG.

In the figure, 101Y, 101M, 10
1C and 101K are the scanning optical device of the present embodiment,
Y, 102M, 102C, and 102K are process cartridges, in which the photoconductor 15, the charger 103, the developing device 104, and the like are housed, and can be replaced according to the life of the photoconductor 14. 105Y, 105M, 10
5C, 105K are transfer rollers, 106 is a conveyor belt, 1
Reference numeral 07 is a recording medium such as paper, and 108 is a fixing device.

The color image forming apparatus prints four colors on the recording medium 107 at once in order to enable high speed printing. Therefore, the scanning optical device 101, the process cartridge 102, and the transfer roller 105 are equipped with four sets corresponding to four colors of yellow, magenta, cyan, and black.

The image forming process of the color image forming apparatus will be described.

The photoconductor 15 is first charged by the charger 103. Next, the scanning optical device 101 forms an electrostatic latent image according to the image signal for each color on the photoconductor 15, and the developing device 104 forms the electrostatic latent image into a toner image.

On the other hand, the recording medium 107 is the conveyor belt 1.
The toner of four colors of black, cyan, magenta, and yellow is transferred by the transfer roller 105 as it is conveyed from right to left in the figure on the upper part of the figure. After that, the recording medium 107 passes through the fixing device 108 to fix the toner, and the recording medium 107 is discharged to the outside of the apparatus.

While this color image forming apparatus has an advantage that high-speed printing can be performed, the scanning optical device 10 for four colors is separately provided.
Since printing is performed using the No. 1 or the process cartridge 102, it is necessary to devise a method for accurately overlapping the colors.

Therefore, in the scanning optical apparatus of the present embodiment, the diffractive optical element 8 is displaced or rotated to tilt or bend the scanning line 16 on the photosensitive member 15 and the left / right difference in scanning speed (hereinafter referred to as one-side magnification). ) Is being adjusted. Further, the inclination of the scanning line 16 can be automatically adjusted in order to correct the inclination of the image which is apt to be displaced by exchanging the process cartridge 102.

Next, the details of the scanning optical device will be described.

First, the adjusting mechanism of the folding mirror 7 will be described in detail with reference to FIG.

The mirror adjusting unit 12 comprises a mirror adjusting table 21, a link 22 and a set screw 23. The mirror adjustment base 21 has a positioning boss 2 on the lower side.
1a protrudes, and the optical box 14 is provided with elongated holes 25 provided in the same number as the bosses 21a.
2, the boss 21a and the elongated hole 25 are used as guide rails to move and adjust in the optical axis direction (direction of arrow M), and the tilt of the folding mirror 7 is adjusted. Further, the mirror adjustment unit 12 is fixed to the optical box 14 by the screw 24 after the movement adjustment.

The folding mirror 7 has a supporting point 26 provided on the optical box 14 and a fulcrum 21 provided on the mirror adjusting base 21.
b, the movable point 22a provided on the link 22 is grounded at three points, and is fixed by the support side spring 27 and the movable side spring 28.

Next, the mirror adjusting unit 12 will be described in detail with reference to FIGS.

In FIG. 4, the mirror adjusting base 21 is simplified and drawn by a two-dot broken line for the sake of explanation, and the movable spring 28 is omitted. Further, FIG. 5 is a sectional view. As shown in FIG. 4, the link 22 has link rotation shafts 22b protruding left and right,
The link rotation shaft 22b has a root portion and left and right restricting portions 22c at a position slightly apart from the root portion. Further, the mirror adjustment base 21 has a U-shaped groove 41 into which the link rotation shaft 22b is inserted.
And a regulation groove 42 into which the left and right regulation portions 22c are fitted, and thereby the link 22 is rotatable while regulating the positional deviation of the link 22 in the width direction. In addition, as shown in FIG. 4, the movable spring 28 is connected to the first arm 51 and the second arm 51.
The first arm 51 has an arm 52, and a load acts on the first arm 51 in the direction of arrow A1 to press the folding mirror 7 against the movable point 22a of the link 22. The second arm 52 pushes the ridge line 7a of the folding mirror 7 and a load acts in the directions of the arrows A2 and A3 to push the folding mirror 7 against the fulcrum 21b provided on the mirror adjusting table 12 and the regulating rib 53.

The movable side spring 28 is hooked in a hooking hole 54 provided in the movable spring 28 on a hook portion 55 projecting from the mirror adjusting base 21, so that the first arm 51 and the second arm 52.
It is fixed to the mirror adjustment table 21 by the reaction force of.

Here, as shown in FIG. 4, the set screw 23
When is rotated in the direction of arrow M1, the link 22 rotates in the direction of arrow M2 with the link rotation shaft 22b as the center of rotation. As a result, the movable point 22a of the link 22 moves up and down, and the folding mirror 7 is moved. At this time, the folding mirror 7 is pressed against the fulcrum 21b and the supporting point 26 on the supporting side by the movable side spring 28 and the supporting side spring 27.
It rotates in the direction of arrow M3 around the line connecting 1b and the support point 26 as an axis.

As described above, the folding mirror 7 has two axes of tilt adjustment by moving the mirror adjusting table 12 in the direction of arrow M (see FIG. 3) and tilting in the direction of arrow M3 by rotating the link 22. Adjustments are made. The operation will be described with reference to FIGS.

First, FIG. 6 shows a state in which the folding mirror 7 is tilted in the direction of the arrow M depending on the precision of parts and the like. In this case, the laser light flux reflected by the back side of the folding mirror 7 passes through the center of the diffractive optical element 8 as shown by the solid line L2.
On the other hand, the laser light flux reflected on the front side does not pass through the center of the diffractive optical element 8 as indicated by the broken line L3. Therefore, the mirror adjusting table 12 is moved in the direction of arrow M, and adjustment is made so that the solid line L2 and the broken line L3 overlap.

Further, FIG. 7 shows a state in which the folding mirror 7 is raised in the direction of the arrow M3 due to the precision of parts and the like.
In this case, the laser light flux reflected by the folding mirror 7 is inclined with respect to the ideal optical path C1 indicated by the one-dot chain line as indicated by L4. Therefore, the link 22 is rotated and the folding mirror is tilted in the direction of the arrow M3 for adjustment.

The folding mirror 7 is adjusted so as to correct an error due to component precision or the like by combining the adjustments in the above two directions and to pass the center of the diffractive optical element 8 over the entire area.

As a result, the spot collapse on the photosensitive member caused by the height shift of the light beam incident on the diffractive optical element 8 and the scanning line inclination automatically generated by the inclination of the light beam incident on the diffractive optical element 8 are automatically detected. It prevents the adjustable range of adjustment from decreasing.

A feature of the folding mirror adjustment of this embodiment is that the link 22 is used to reduce the sensitivity of the tilt adjustment and to perform the adjustment with high accuracy. The sensitivity of the adjustment is that the pitch of the set screw 23 is P, the distance from the link rotation shaft 22b of the link 22 to the position where the set screw 23 contacts is X1, the distance to the movable point 22a is X2, and the fulcrum 21b.
And the movable point 22a is Y, the folding mirror 7
The tilt angle θ and the rotation angle α of the set screw have the relationship of Expression 1.

[0035]

[Equation 1]

Further, from the folding mirror 7 to the diffractive optical element 8
Assuming that the distance is up to L, the height deviation amount Δ of the laser light flux on the diffractive optical element 8 with respect to the tilt angle θ of the folding mirror 7 becomes as shown in the following equation 2.

[0037]

[Equation 2]

Therefore, as is clear from the equations 1 and 2, the arm ratio (X1 / X2) of the link 22 may be increased as much as possible in order to reduce the sensitivity of adjustment, that is, the effect of Δ with respect to the angle α. .

Further, according to the present embodiment, since the arm ratio (X1 / X2) of the link 22 can be freely selected, it is possible to select an appropriate one from the adjustment range and the sensitivity, and the folding back can be performed with extremely high accuracy. It is possible to adjust the tilt of the mirror 7.

Next, the principle of adjustment of the diffractive optical element 8 will be described with reference to FIGS.

The inclination adjustment of the scanning line 16 is performed in order to correct the image inclination difference between the respective colors. This changes depending on the precision of the components inside the scanning optical device, but most of them are the photosensitive member 15.
And the parallelism of the scanning optical device and the parallelism between the photoconductors 15. Also, since the photoconductor 15 is replaced, the image inclination changes with time. Therefore, in this embodiment, automatic adjustment is possible.

As shown in FIG. 8, this is done by tilting the diffractive optical element 8 in the direction of arrow T from the initial position indicated by the chain double-dashed line, as indicated by 8a. As a result, the scanning line 16 is tilted as shown by 16a from what is indicated by the chain double-dashed line.

As for the bending of the scanning line 16, as shown in FIG. 9, the diffractive optical element 8 is rotated in the direction of arrow B from the initial position indicated by the chain double-dashed line 8b. As a result, the scanning line 16 is curved as shown by the double-dotted chain line to 16b.

The bending of the scanning line 16 is caused by a height shift or a bow of each optical component, and the diffractive optical element 8 corrects this and reaches a position where the diffractive optical element 8 forms a substantially straight line as shown by the chain double-dashed line 16. Rotation is adjusted.

The one-side magnification is caused by the optical axis shift of the toric lens 6 and the diffractive optical element 8 in the main scanning direction (positional shift in the horizontal direction in FIG. 10). Specifically, when the optical axes of the toric lens 6 and the diffractive optical element 8 are aligned as indicated by the chain double-dashed line in FIG. 10, the right end of the toric lens 6 is
The light rays passing through the center and the left end are 5 on the photoconductor 15 respectively.
The position of 1, 52, 53 is reached.

On the other hand, when the diffractive optical element 8 is laterally displaced as shown by the solid line 8c, the rays passing through the right end, the center and the left end of the toric lens 6 are 51a, 51b and 51, respectively.
Like c, the left and right ends move in the same direction as the displacement direction of the diffractive optical element 8, and the center moves in the opposite direction. As a result, the scanning speed is faster on the right side, slower on the left side, and the right side of the image extends and the left side contracts.

Therefore, in this embodiment, the diffractive optical element 8 is moved to the left and right to adjust the one-side magnification.

Next, the adjusting mechanism of the diffractive optical element 8 will be described in detail with reference to FIG.

In the figure, 61 is a support plate, and 62, 63.
Is a fixed spring, 64 is a left / right adjusting shaft, 65 is a left / right adjusting spring,
66 is a bearing, 67 is a nut, 68 is a rotation adjusting screw, 6
8a is a washer, 69 is a rotation adjusting spring, 70 is a sliding bearing, 71 is a tilt adjusting table, 72 is a tilt adjusting spring, and 73 is a tilt adjusting spring.
Is a play removing spring, and 74 is a guide shaft.

Reference numerals 75 to 79 are parts constituting the tilt adjusting unit 13, and 75 is the pinion gear 7 at the tip of the rotating shaft.
Reference numeral 6 is a stepping motor, and 78 is a cam gear.

Here, the diffractive optical element 8 is fixed to the support plate 61 by using fixing springs 62 and 63 and screws 80a and 80b, and a threaded bearing 70 is fixed to the support plate 61 by screws 80c.

FIG. 12 is a view seen from the exit side of the diffractive optical element 8. As shown in the figure, the center line of the diffractive optical element 8 is arranged on the axis line (one-dot chain line Z) that passes through the axis 71c protruding substantially parallel to the main scanning direction from the left-right adjustment shaft 65 and the tilt adjustment base 71.

Next, the one-sided magnification adjusting mechanism is shown in FIGS.
4 will be described.

The bearing 66 is fitted in a fitting hole 82 formed in the side wall 81 of the optical box 14 as shown in FIG.
Further, the bearing 66 has a fixing screw portion 66a, and the left and right adjusting springs 65 have a nut-shaped portion 65a. The fixing screw portion 66a is screwed into the nut-shaped portion 65a, so that the side wall 81 is sandwiched between the bearing 66. The left and right adjusting springs 65 are fixed. (In FIG. 13, the left and right adjusting springs 65 are omitted for the sake of explanation.) Further, the support plate 61 has a bent portion 61a with a shaft through hole 61b, and the bearing 66 has a through hole 66b. Right and left adjustment shaft 64
Is inserted into the shaft through hole 61b and the through hole 66b, and a screw portion 64a provided at the tip of the screw protrudes to the opposite side of the bearing 66. The nut 67 is a screw portion 64 of the left / right adjustment shaft 64.
detent 67a engaged with a and provided on the nut 67
Is prevented from engaging with the sleeve 66c provided on the bearing 66 and rotating around the left and right adjusting shafts.

FIG. 14 is a sectional view of the portion shown in FIG.

The left and right adjusting shaft 64 is thicker than the shaft main body on the side opposite to the screw portion 64a and has a tapered head portion 64b.
have. The left and right adjustment springs 65 are the pressure arms 65b.
This elastic force pushes the bent and raised portion 61a of the support plate 61 to move the support plate 61, the left-right adjustment shaft 64, and the nut 67 to the left side in the drawing, but the nut 67 hits the bearing 66. As a result, this movement is stopped, and the support plate 61, the left-right adjustment shaft 64, and the nut 67 are fixed.

Here, when the left and right adjusting shafts 64 are rotated,
The left and right adjusting shaft 64 moves left and right by the action of the screw portion 64a engaged with the nut 67. Since the support plate 61 is pressed against the head portion 64b of the left / right adjustment shaft 64 by the pressure arm 65b, the support plate 61 also moves left / right together with the left / right adjustment shaft 64. At this time, the opposite side of the support plate 61 is shown in FIG.
As shown in FIG. 2, it is restricted by the shaft 71c of the tilt adjusting base 71 held by the thread bearing 70 and can be smoothly moved left and right without tilting. Then, the diffractive optical element 8 fixed to the support plate 61 is also moved to the left and right integrally with the support plate 61, and the optical axis of the toric lens 6 is adjusted to adjust the one-side magnification.

Next, the bending adjusting mechanism of the scanning line 16 will be described with reference to FIG.

In the figure, numeral 85 is a female screw cut on the optical box 14. Further, the bending adjustment spring 69 is provided on the support plate 61.
The L-shaped portion 86 bent and bent from is biased to the bending adjustment screw 68 and the washer 68a.

In this adjustment, the support plate 61 rotates about the axis Z in the direction of arrow B by rotating the rotation adjusting screw 68. Then, the diffractive optical element 8 fixed to the support plate 61
Also rotates around the axis Z as a unit to adjust the bending of the scanning line.

As described above, the axis Z is arranged so that the center of the diffractive optical element 8 passes through it, and the diffractive optical element 8 does not cause a positional displacement even if it is rotated by this adjustment.

Therefore, even if this adjustment is carried out, the collapse of the spot and the focus deviation due to the displacement of the diffractive optical element 8 will not occur.

Further, the female screw 85 may not be provided on the optical box 14, but may be formed by pressing another member such as a bit.

Next, the automatic adjustment mechanism of the inclination of the scanning line will be described with reference to FIG.

The cam gear 78 has a gear portion 78a and a cam surface 78b with a gentle slope.
a is connected to the pinion gear 76, and is connected to the stepping motor 7
The rotation of 5 rotates the cam gear 78.

The tilt adjusting base 71 has a sliding hole 71a therein, and a guide shaft 74 projecting from the optical box 14 substantially parallel to the sub-scanning direction is fitted therein, and the tilt adjusting base 71 is guided. It is movable in the sub-scanning direction (vertical direction in the drawing) along the axis 74. Further, a pivot 71b is provided on the upper part of the tilt adjusting base 71, and is in contact with the cam surface 78b by the force of the tilt adjusting spring 72. Further, in the tilt adjusting base 71, the shaft 71c is held in the thread bearing 70 and is connected to the support plate 61.

The support plate 61 tries to rotate by its own weight as shown by the chain double-dashed line in FIG. Then, the diffractive optical element 8 also rotates in the same direction, which causes adverse effects such as focus shift. In order to prevent this, a substantially cylindrical guide rail 83 protruding from the optical box 14 is provided. Support plate 61
When it rotates by its own weight, the inclination adjusting base 71 also tries to rotate around the guide shaft 74 in the direction of the arrow T1 along with it. However, the guide rail 83 is attached to the tilt adjustment table 71.
This rotation is suppressed by the contact of the upper wall 71d. The guide rail 83 has a substantially cylindrical shape in order to reduce the contact area with the upper wall 71d so that the frictional resistance of this portion does not hinder the movement of the tilt adjusting base 71.

Here, when the stepping motor 75 rotates, the cam gear 78 connected to the pinion gear 76 also rotates, the height of the cam surface 78b in contact with the pivot 71b changes, and the tilt adjusting base 71 of FIG. Move up and down. Then, the support plate moves in the same direction in conjunction with it. On the other hand, since the opposite side in the longitudinal direction of the support plate is fitted to the left and right adjustment shaft 64 as described above, this side is not movable, and the support plate 61 uses the center of the shaft through hole 61b as a fulcrum.
It rotates about an axis substantially parallel to the main scanning direction. As a result, the diffractive optical element 8 fixed to the support plate 61 also rotates in the same manner, and the scanning line can be tilted.

As shown in FIG. 18, the thread sleeve 70 has a thread 70a and an insertion hole 70b having an inner diameter slightly smaller than the outer diameter of the axis 71c. When the axis 71c is inserted into the thread sleeve 70a, the thread 70a is inserted. Opens and the shaft 71
c is held, and the sleeve 70a is opened even when the shaft 71c is tilted so that it can be slightly rotated in the direction orthogonal to the shaft 71c.

This is because the main scanning direction (arrow X direction) and rotation about the X axis of the arrow are orthogonal to this between the support plate 61 and the tilt adjustment table 71 for adjusting the tilt and bending of the scanning line and one-sided magnification. Arrow having a three degree of freedom of rotation about the Y-axis, and play occurs between the tilt adjustment base 71 and the support plate 61,
The positional relationship between the support plate 61 and the tilt adjustment base 71 is changed to prevent the linearity of the scanning line tilt automatic adjustment from being destroyed.

In addition, as shown in FIG.
Is tilted slightly in the direction of arrow T by the force of the play removing spring 73 arranged substantially parallel to the tilt adjusting spring 74 to remove the fitting play generated between the sliding hole 71a and the guide shaft 74. This is to prevent the posture of the tilt adjusting table 71 from changing due to looseness when the tilt adjusting base 71 moves up and down, and to prevent the linearity of the automatic adjustment of the scan line tilt from collapsing.

FIG. 19 shows the effect of removing these backlashes.

In the figure, the horizontal axis shows the number of operation pulses of the stepping motor 75, the vertical axis shows the amount of inclination of the scanning line, the solid line shows the case without the rattling mechanism, and the broken line shows the case with the rattling mechanism.

As is clear from the figure, when there is no backlash removing mechanism, the portion surrounded by a circle A in the middle has a remarkable collapse of linearity. This is because the posture of the tilt adjusting base 71 is changed or the positional relationship with the support plate 61 is changed at this time.

On the other hand, when there is a backlash removing mechanism, there is no remarkable collapse of linearity, and good linearity is maintained.

Further, this backlash removing mechanism prevents the diffractive optical element 8 from displacing in an unnecessary direction even during the above-mentioned one-sided magnification adjustment and bending adjustment, and prevents each adjustment from affecting each other. Therefore, highly accurate scanning line inclination, bending, and one-sided magnification adjustment are realized.

As described above, by using this embodiment, the folding mirror 7 can be adjusted with high accuracy and the linearity of the automatic adjustment of the scanning line inclination can be kept good.

[0078]

As described above, according to the present invention,
The folding mirror 7 can be adjusted with high accuracy, and the linearity of the automatic adjustment of the scanning line inclination can be kept good,
It is possible to provide a scanning optical device that has very little color misalignment and is optimal for a color image forming apparatus.

[Brief description of drawings]

FIG. 1 is a perspective view showing a scanning optical device according to an embodiment of the invention.

FIG. 2 is a diagram showing a color image forming apparatus equipped with a scanning optical device according to an embodiment of the invention.

FIG. 3 is a perspective view showing a mirror adjustment mechanism of the scanning optical device according to the embodiment of the invention.

FIG. 4 is a perspective view showing a mirror adjustment unit of the scanning optical device according to the embodiment of the invention.

FIG. 5 is a cross-sectional view showing a mirror adjustment unit of the scanning optical device according to the embodiment of the invention.

FIG. 6 is a diagram illustrating the principle of mirror adjustment of the scanning optical device according to the embodiment of the present invention.

FIG. 7 is a diagram showing a principle of mirror adjustment of the scanning optical device according to the embodiment of the invention.

FIG. 8 is a diagram showing the principle of scanning line inclination adjustment of the scanning optical device according to the embodiment of the invention.

FIG. 9 is a diagram showing the principle of scanning line bending adjustment of the scanning optical device according to the embodiment of the present invention.

FIG. 10 is a diagram illustrating a principle of one-sided magnification adjustment of the scanning optical device according to the embodiment of the invention.

FIG. 11 is a perspective view showing an adjusting mechanism of the diffractive optical element of the scanning optical device according to the embodiment of the invention.

FIG. 12 is a diagram showing an adjustment mechanism of a diffractive optical element of a scanning optical device according to an example of the present invention.

FIG. 13 is a perspective view showing a half-magnification adjusting mechanism of the diffractive optical element of the scanning optical device according to the embodiment of the invention.

FIG. 14 is a cross-sectional view showing a one-sided magnification adjusting mechanism of the diffractive optical element of the scanning optical device according to the embodiment of the invention.

FIG. 15 is a sectional view showing a bending adjustment mechanism of the diffractive optical element of the scanning optical device according to the embodiment of the present invention.

FIG. 16 is a diagram showing a scanning line inclination adjusting mechanism of the diffractive optical element of the scanning optical device according to the example of the invention.

FIG. 17 is a diagram showing a scanning line tilt adjusting mechanism of the diffractive optical element of the scanning optical device according to the example of the invention.

FIG. 18 is a diagram showing a scanning line tilt adjusting mechanism of the diffractive optical element of the scanning optical device according to the example of the invention.

FIG. 19 is a diagram showing the effect of the backlash removing mechanism of the scanning optical device according to the embodiment of the invention.

[Explanation of symbols]

6 toric lens 7 folding mirror 8 Diffractive optical element 12 Mirror adjustment unit 13 Tilt adjustment unit 14 Optical box 21 Mirror adjustment stand 21a Boss 21b Support point 22 links 22a movable point 22b Link rotation axis 22c Left and right control section 23 set screws 25 slot 26 Support points 27 Support side spring 28 Movable spring 41 U-shaped groove 42 Left and right restriction groove 61 Support plate 64 left and right adjustment axes 65 Left and right adjustment springs 66 bearings 67 nuts 68 Rotation adjustment screw 69 Rotation adjustment spring 70 Sliwari Bearing 71 Tilt adjustment stand 71b pivot 71c axis 72 Tilt adjustment spring 73 Backlash removal spring 74 Guide shaft 75 stepping motor 76 pinion gear 78 Cam Gear 78b Cam surface 83 Guide rail

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/113 H04N 1/04 104A F term (reference) 2C362 AA07 AA10 BA50 BA87 BB16 CA22 DA03 2H045 AA01 BA22 BA34 CA33 DA02 DA04 5C051 AA02 CA07 DB24 DB30 DC07 DE24 5C072 AA03 DA02 DA04 DA23 HA02 HA09 HA13 HB08 QA14 XA05

Claims (6)

[Claims] 1. A laser light source, a deflection means for deflecting a laser light flux emitted from the laser light source, and one or a plurality of imaging means for scanning and imaging the laser light flux deflected by the deflection means on an image carrier. And a reflecting mirror disposed in front of the one image forming unit or between the plurality of image forming units,
In a scanning optical device having a reflecting mirror adjusting mechanism for adjusting the direction of a laser beam provided on the reflecting mirror, the reflecting mirror adjusting mechanism displaces one longitudinal end of the reflecting mirror in the optical axis direction. And a link included in the adjustment table, and a mechanism for rotating the link about an axis substantially parallel to the longitudinal direction by rotating the link. 2. A registration adjusting mechanism for adjusting the inclination of a scanning line on the image carrier by automatically rotating at least one of the image forming means about an axis substantially parallel to the optical axis. The scanning optical device according to claim 1, further comprising: 3. A laser light source, a deflection means for deflecting a laser light flux emitted from the laser light source, and one or a plurality of imaging means for scanning and forming an image on the laser light flux deflected by the deflection means. Scanning at least on the image carrier by displacing or rotating one of the image forming means and a reflecting mirror arranged in front of the one image forming means or between the plurality of image forming means. A registration adjusting mechanism for adjusting the inclination of a line, wherein the registration adjusting mechanism automatically rotates one of the image forming means about an axis substantially parallel to the optical axis. A scanning optical device comprising a mechanism for adjusting the inclination of a scanning line on a carrier. 4. The registration adjusting mechanism rotates with a motor, following rotation of the motor, a cam gear having an inclined cam surface, and movable in the sub-scanning direction following rotation of the cam gear. One of a moving table, a biasing means for biasing the moving table to the cam gear, and the image forming means.
A supporting plate for supporting the moving table and a connecting means for connecting one end of the moving plate to the longitudinal direction of the supporting plate, and the supporting plate is provided on the side opposite to the connecting means in association with the movement of the moving table. The scanning optical device according to claim 2, wherein the scanning optical device rotates about an axis substantially parallel to the optical axis with one end as a center. 5. The moving base has a sliding hole substantially parallel to the sub-scanning direction, and the sliding hole projects substantially parallel to the sub-scanning direction from a housing containing the registration adjusting mechanism. Is inserted into the guide shaft, the movable base is movable along the guide shaft, and is arranged substantially parallel to the urging means, and the movable base is tilted to eliminate looseness of engagement with the guide shaft. 5. The scanning optical device according to claim 4, further comprising: a backlash removing means. 6. The connecting means has a substantially cylindrical bearing part having a notch in a part thereof, and the movable table projects substantially parallel to a main scanning direction and has a shaft part thicker than an inner diameter of the bearing part. The shaft portion protruding from the movable table is inserted into the bearing portion.
5. The scanning optical device according to item 5.