JPH04166354A - Optical writing device - Google Patents

Abstract

PURPOSE:To position a holding member to a photosensitive body with high accuracy, prevent the deformation of the holding member, and obtain an optical writing device having a stably high resolving power by a method wherein the position or attitude of the holding frame is finely adjusted by rotating an eccentric horizontal shaft, an eccentric vertical shaft, an eccentric erect shaft, and a pressing screw member. CONSTITUTION:The inclining amount or Y-axis direction travel amount of a writing unit 100 is finely adjusted by rotating right and left cylindrical cams 87, 92. The inclining amount of the writing unit 100 is finely adjusted by rotating right and left cylindrical cams 117, 134. The inclining amount or Z-axis direction travel amount of the writing unit 100 is finely adjusted by rotating eccentric round shafts 80, 83. The X-axis direction travel amount of the writing unit 100 is finely adjusted by rotating an adjusting screw 72. Namely, in the optical writing by the writing unit 100 to a photosensitive drum 31, the unit 100 is positionally adjusted in main- and sub-scanning directions with high accuracy and positioned in the optical axis direction of an SLA 111 to ensure a high-resolution image forming. The image forming position of the SLA 111 on the photosensitive drum 31 can be easily adjusted with high accuracy by a holding mechanism 55. The optical image of the SLA 111 can be formed on the photosensitive drum 31 with high resolution.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical writing device used in an electrostatic recording device, etc., and more specifically, the present invention relates to an optical writing device used in an electrostatic recording device or the like. The present invention relates to an optical writing device that forms a light image of a light emitting element array onto a photoreceptor using a convergent light transmitting body array.

[Conventional technology]

Conventionally, in an electrostatic recording device using an optical writing device, a laser beam is deflected by a rotating polygon mirror, and an extremely small beam spot is focused on the photoreceptor surface by an fθ lens, thereby creating an electrostatic latent image according to an image signal. However, the optical path length from the light emitting source to the photoreceptor was several hundred meters long.
rm is also available, and because it uses a high-speed rotating body, the device is large and expensive. Therefore, recently, instead of lasers, devices have been developed that use light emitting diode arrays (LED arrays) or liquid crystal shutter arrays arranged in series in the main scanning direction and whose blinking is controlled by image signals or liquid crystal shutter arrays as a writing light source. Products with a length in the main scanning direction of about 1000 mm are commercially available, and are also used as wide-width optical writing devices for print output in CAD (computer-aided design).

Conventional optical writing devices of this type are configured to form a dot-shaped optical image on a photoreceptor using a convergent light transmitting array (hereinafter referred to as SLA). Therefore, the distance (TC) from the light source to the photoreceptor is as short as 15111 m to 60 aus. Therefore, the space occupied by the writing device is small, making it possible to downsize the electrostatic recording device.

[Problem to be solved by the invention]

However, in such conventional optical writing devices, the output of a writing light source such as an LED array or a liquid crystal shutter was extremely small compared to the output of a laser light source, so SLA, which forms an image of this output on a photoreceptor, is , it had to have a small F value and sufficiently bright imaging characteristics.

However, SLA has the characteristic that when its brightness is high, the imaging focal depth becomes small.
The LA-97C4B has an F value of 2.72 and a depth of focus of ±0.
6+ms, whereas 5LA-20TC18m-
In this case, the F value is 0.96, which makes it brighter, but the depth of focus is ±
It becomes small as 0.3II11. Therefore, the relative position between the light emitting surface of the LED array or the like and the SLA, and the relative position between the SLA and the photoreceptor surface require highly accurate positioning over the entire main scanning direction. Moreover, S.L.A.
The position of the light emitting surface and photoreceptor surface relative to the (±) direction or (−
) If they are shifted in the same direction, the resolution (MTF) will not decrease much, but if they are shifted in the opposite directions (+) and (-), the MTF will be extremely reduced. As a result, even if the LED array and SLA are held at predetermined relative positions, it is extremely difficult to position and hold them with high precision over the entire main scanning direction, especially for A zero size 1 width and 36# width. In some cases, the length of the member for positioning and holding the LED array and SLA in predetermined positions is 1000 mm or more, and it is extremely difficult to position this holding member with high precision over the entire main scanning direction. Furthermore, the holding member requires highly accurate positioning not only in the optical axis direction of the SLA, but also in the main scanning direction and sub-scanning direction with respect to the photoconductor, as well as the inclination around the optical axis of the SLA and the inclination of the optical axis. However, in the past, no position adjustment was made in the direction of inclination, and the
JP-A-157354 and Japanese Patent Publication No. 1-502806 only disclose techniques for adjusting the position in the optical axis direction.

Furthermore, in the optical writing device used for writing with A zero width or 36'' width as mentioned above, the power required per one dot of the LED array etc. is about 15 milliwatts, but the total number of dots can reach about 14,000 dots. When all the dots are lit at the same time, it reaches 210,000 milliwatts (210 watts), and the heat generation inevitably causes thermal deformation in the holding member, especially thermal expansion that occurs in the main scanning direction of the holding member. curvature occurs in the optical axis direction due to the MTF
There was a problem that the value decreased. On the other hand, Japanese Patent Laid-Open No. 1-278376 discloses a method in which the SLA held by the holding member is bent in advance in the same direction to compensate for the bending (deformation) of the holding member due to heating. ,
No means for preventing thermal deformation of the holding member itself is disclosed. Furthermore, as mentioned above, when the length of the holding member in the main scanning direction is as much as 1000++ m, the holding member is distorted in the optical axis direction of the convergent light transmitter array due to large thermal expansion in the main scanning direction due to heat generation of the light emitting light source. In order to prevent this, effective heat dissipation cooling is required, but a means for minimizing thermal deformation of the holding member by actively dissipating and cooling the heat generated by a light emitting light source such as an LED array has also been disclosed. Not yet.

That is, in a conventional optical writing device, a photoreceptor,
There has been a problem in that relative positioning of the light emitting element array and the convergent light transmitting body array with a holding member that holds the light emitting element array and the convergent light transmitting body array at predetermined relative positions cannot be performed sufficiently.

[Purpose of the invention]

Therefore, the invention as claimed in claim 1 performs highly accurate positioning by finely adjusting the relative position between the holding member and the photoreceptor in each direction, and also prevents distortion due to thermal deformation of the positioned holding member and holding by fastening force. An object of the present invention is to provide an optical writing device that prevents deformation of the member and has stable high resolution, and furthermore, even if the holding member is long, the entire holding member can be fixed. An object of the present invention is to enable highly accurate position adjustment, and in addition, the invention as claimed in claim 3 provides a method for adjusting the position in the main scanning direction and in the sub-scanning direction while ensuring highly accurate positioning accuracy in the optical axis direction of the convergent light transmitter array. The purpose is to enable adjustment of the amount of movement in the scanning direction.

[Means to solve the problem]

To achieve the above object, the invention according to claim 1 provides a light emitting element array arranged in series in the main scanning direction and blinking controlled by an image signal, and a secondary light emitting element array rotatably supported by an immovable member. An optical writing device comprising a photoreceptor that moves in a scanning direction and a convergent light transmitter array that forms a light image of a light emitting element array on the photoreceptor, the light emitting element array and the convergent light transmitter array a holding member that integrally positions and holds the stationary member at a predetermined relative position; a locking frame that is positioned and locked at a predetermined position of the immovable member; and a locking frame that is attached to both ends of the holding member in the main scanning direction, and A plurality of concentric horizontal axes and eccentric horizontal axes that extend parallel to each other in the main scanning direction, and a plurality of concentric horizontal axes and eccentric horizontal axes that extend in the sub-scanning direction so as to be able to interfere with each other, and both ends of the holding member in the main scanning direction. provided at both ends of the locking frame in the main scanning direction so as to be able to block a plurality of eccentric vertical shafts that are rotatably supported by the locking frame at the sides and a concentric horizontal shaft;
An eccentric upright shaft extending in the optical axis direction of the convergent light transmitter array and a rotary pusher interposed between the holding member and the locking frame to push the holding member in the main scanning direction relative to the locking frame. A moving member is provided, and the position or attitude of the holding frame is adjusted by 'RX' by rotating any one of the eccentric horizontal shaft, eccentric vertical shaft, eccentric vertical shaft, and rotary pushing member. It is.

Furthermore, the invention according to claim 2 provides a Z-direction adjusting screw that moves forward and backward in the optical axis direction of the convergent light transmitting body array at the center of the holding member in the main scanning direction, and the holding member is rotated by rotation of the adjusting screw. The invention according to claim 3 is characterized in that the amount of movement of the central portion in the main scanning direction is finely adjusted, and the invention according to claim 3 is characterized in that the concentric horizontal axis and the eccentric horizontal axis are arranged on the eccentric vertical axis in the main scanning direction. This feature is characterized in that it is supported slidably in both the scanning direction and the sub-scanning direction.

Hereinafter, the present invention will be explained based on examples.

1 to 8 are diagrams showing an embodiment of an optical writing device according to the invention as claimed in claims 1 to 3, and show an example in which the invention is applied to a dry electrophotographic electrostatic recording device.

First, the configuration will be explained.

In FIG. 1, 10 is an electrostatic recording device, 11 is a lower casing of the electrostatic recording device IO, and 12 is a support shaft 13 on the lower casing 11.
14 is an operation panel provided at the front end of the upper housing 12. In this electrostatic recording apparatus lo, left and right side plates 15L and 15R are provided within the lower housing 11 at a predetermined interval, and a photosensitive drum 31 is rotatably supported on the left and right side plates 15L and 15R. The photosensitive drum 31 is rotated in the direction of the arrow (sub-scanning direction) in the figure, and the charger 3
2 uniformly charges the surface of the photosensitive drum 31.
The optical writing device 50 located directly above the image signal is exposed in accordance with the input image signal. Due to this exposure, an electrostatic latent image is formed on the photoreceptor drum 31, and this is visualized by the developing device 33 to become a toner image. On the other hand, feeding roller 3
Transfer paper 3 conveyed to registration roller 36 by 5
4 is fed between the photoreceptor drum 31 and the transfer charger 37 at a predetermined timing by the registration roller 36, and the toner image on the photoreceptor drum 31 is transferred onto the transfer paper 34 by the transfer charger 37. This transfer paper 34 is separated from the photosensitive drum 31 by a separation charger for 3 days,
The toner image is transported by a transport belt 39 to a fixing device 4o, where the toner image is heated and fixed, and then discharged onto a discharge tray 42 by a discharge roller 41. After the toner image has been transferred, the photosensitive drum 31 has residual toner removed by a cleaning device 43, and then reaches the charging area again to repeat the image forming process again. The image forming process described above is similar to that of a known electrophotographic apparatus, and a detailed explanation of the configuration will be omitted. In addition, 20 is an air blower provided in the upper housing 12 so as to face the optical writing device 50, and the air blower 20 cools the optical writing device 50 by blowing air. The optical writing device 50 is rotatably supported on the left and right side plates 15L, 15R via support shafts 16L, 16R on the rear side thereof, and the left and right locking arms 64L, 64R on the front side of the optical writing device 50 are left and right side plates 15L, 15
A screw 18 is attached to the locking bases 17L and 17R formed on the upper part of R.
It is locked by L and 18R.

In FIG. 2.7, the blower device 20 has a blower 21 and a filter 22, and the clean air filtered by the filter 22 is forcibly sent downward toward the optical writing device 50 by the blower 21. The air flows through the air guide path 23.24 while removing heat from the heat radiation fins 102 of the LED array holding member 101, and from the nozzle 25.26 to the 5LA.
The light ejects strongly onto the light exit surface 111a of III.

Note that the distance between the light exit surface 111a of 5LAIII and the surface of the photoreceptor drum 31 is extremely close, for example, 4.8n+n+, based on the brightness of SLAIII, and the distance between the light exit surface 111a of 5LAIII and the surface of the photoreceptor drum 31 is extremely close, for example, 4.8n+n+, and the distance between the light exit surface 111a of 5LAIII and the surface of the photoreceptor drum 31 is extremely close, for example, 4.8n+n+. If dust such as toner powder or paper dust passes through the gap, it tends to adhere to the light exit surface 111a and cause the written image to be missing or deteriorated. This prevents the light from being blown off and attached to the light exit surface 111a.

The length of the optical writing device 50 in FIG. 8 is, for example, 100 (
It has a writing unit 100 of approximately lsa+ and a holding frame 60 (locking frame) that holds it, and the writing unit 100 includes an LED array arranged in series in the main scanning direction and blinking controlled by an image signal. 104 (light emitting element array), and the light image of the LED array 104 is transferred to the photoreceptor drum 3.
Selfox lens array 111 (
A convergent light transmitter array (hereinafter referred to as 5LA111) is provided.

In this case, the writing unit 100
The writing width in the upper main scanning direction is 36' (914mm)
It is. Furthermore, in the writing unit 100, the LE
LED array holding member 101 holding D array 104
and an SLA holding member 110 holding 5LAIII are integrally connected by screws 112, and these holding members 101 and 110 integrally position and hold the LED arrays 04 and 5LAIII at predetermined relative positions. Further, the LED array holding member 101 is formed with radiation fins 102 and a center beam 103 extending in the main scanning direction, and a control board 105 is attached.

The holding frame 60 includes left and right side plates 15L and 15R, which are immovable members.
The support shafts 16L, 16R and the locking stand 17L are placed in the predetermined positions of the
, 17R, and a holding mechanism 55 to be described later.
100 is held so that its installation position and orientation can be adjusted.

A convex portion 6'la on the front wall 61 and a convex portion 66a on the rear wall 66 are provided in the longitudinal center of the holding frame 60, and both convex portions 61a and 66a are perpendicular to the longitudinal direction. An elongated finger member 74 is attached. Both retaining members 101 and 110 are attached to the angle 106 and the adjusting screw 75 (Z
is supported on this finger member 74 by a direction adjustment screw),
As a result, the writing unit 100 can swing in any direction relative to the holding frame 60, and by adjusting the adjustment screw 75, the central part of the writing unit 100 in the main scanning direction can be moved in the optical axis direction (Z direction).

Further, the holding frame 60 houses the holding mechanism 55 that finely adjusts the position and installation attitude of the writing unit lOO, and this holding mechanism 55 is located at the third. It is configured as shown in Figure 5. First, both holding members 101 and 110 are integrally connected.
A right support block 113 is screwed onto the right support block 113, and a concentric round shaft 116 and a concentric round shaft 114 extending in the main scanning direction (X direction) are screwed onto the right support block 113 with a certain height difference. It is worn. An eccentric right cylindrical cam 117 is attached to the concentric round shaft 114 so that its rotation can be adjusted by a set screw 118 and a brake (not shown) with a predetermined eccentricity.
This right cylindrical cam 117 abuts on the eccentric round shaft 80 extending in the sub-scanning direction, and the concentric round shaft 116 directly abuts on the eccentric round shaft 80.
LAIII is positioned and supported in the optical axis direction. In addition, the other end small diameter portion 114 of these shafts 114 and 116
a, 116a is the fixing pin 1.22.1 on the holding frame 60 side
23 is biased toward the bottom wall 70 side of the holding frame 60, and when the right cylindrical cam 117 is rotated about the concentric round shaft 114, the writing The unit 100 moves slightly up and down on the front side,
Inclination β of the LED array 104 in the sub-scanning direction (Y direction)
is finely adjusted. The eccentric round shaft 80 has a concentric large diameter shaft portion 80a.
, 80d, groove portions 80b, 80e, and eccentric small diameter shaft portion 80c
The concentric large diameter shaft portions 80a and 80d are the holding frame 6.
It is rotatably fitted into fitting holes 62A and 62B formed at 0. A brake element 81 made of hard synthetic resin is pressed by a set screw 82 into grooves 80b and 80e formed in the concentric large diameter shaft parts 80a and 80d, and the eccentric round shaft 80 is pulled out by both splitters 81. is fixed, and can be rotated by adjusting the set screw 82. That is, the eccentric round shaft 80 is attached to the holding member 1 so as to extend in the sub-scanning direction.
It is rotatably supported by the holding frame 60 on the right end side in the main scanning direction of 01.110.

The eccentric small diameter shaft 80c of this eccentric round shaft 80 is the concentric large diameter shaft 80c.
The right end of the writing unit 100 supported by the eccentric small diameter shaft 80c moves up and down as the eccentric round shaft 80 rotates.
The inclination α of the optical axis of the LED array 104 in the main scanning direction is finely adjusted. Furthermore, the right support block 113 has a pin 141
．． The holding frame 60 is biased toward the rear wall 66 side of the holding frame 60 by a tension spring 142 via the concentric round shaft 143.
16 abuts against an upright round shaft 86 attached to the right bottom wall 70a of the holding frame 60 via a right cylindrical cam 87. This right cylindrical cam 87 is rotatably fixed to the upright round shaft 86 by a set screw 88, and when the right cylindrical cam 87 is rotatably adjusted, the direction of horizontal rotation of the writing unit 100, that is, the LED array The inclination (γ) of the holding members 101 and 110 with respect to the photoreceptor drum 31 is finely adjusted around the optical axis 104. Further, a protrusion 71 protruding from the right bottom wall 70a of the holding frame 60 is provided adjacent to the right support block 113, and an adjustment screw 7 extending in the main scanning direction is provided on the protrusion 71.
2 and a set screw 73 that prevents rotation thereof via a brake (not shown) are screwed together. This adjustment screw 72 abuts against the right support block 113 from one direction in the main scanning direction.
The writing unit 100 is positioned in the main scanning direction by urging the right support block 113 toward the right side wall 68 of the holding frame 60 by a tension spring 129 via pins 124 and 128.

On the other hand, at the left end in the main scanning direction of writing unit 00, as shown in FIG.
A left support block 131 is screwed onto the left support block 131, and a concentric round shaft 12 extending in the main scanning direction is attached to the left support block 131.
6 and a concentric round shaft 115 are screwed together with a certain height difference. In addition, a left cylindrical cam 134 is attached to the concentric round shaft 115.
is mounted so as to be rotatably adjustable with a predetermined eccentricity by a set screw 135 and a brake (not shown), and this left cylindrical cam 134 abuts on an eccentric round shaft 83 extending in the sub-scanning direction, and a concentric round shaft 126 directly abuts on the eccentric round shaft 80, and the left end side of the writing unit 100 is positioned and supported in the optical axis direction of the 5LA 111. Also, these round shafts 1
The small diameter portions 114a and 116a at the other end of 14.116 are urged toward the bottom wall 70 side of the holding frame 60 by tension springs 136.137 stretched between the pins 138 and 139 of the holding frame 60. , when the left cylindrical cam 134 is rotationally adjusted with respect to the concentric round shaft 115, the writing unit 1oo slightly moves up and down on the front side, and the amount of inclination (β) of the LED array 104 in the sub-scanning direction is slightly adjusted. be adjusted. The eccentric round shaft 83 is
Consisting of concentric large diameter shafts 83a, 83ci, grooves 83b, 83e, and eccentric small diameter shaft 83c, the concentric large diameter shafts 83a, 83
d are rotatably fitted into fitting holes 63A and 63B formed in the holding frame 60. Moreover, the concentric large diameter shaft 83a
, 83d, and grooves 83b and 83e are provided with setscrews 8.
A hard synthetic resin brake 84 is pressed against the eccentric round shaft 83 by the brake 84, and the eccentric round shaft 83 is prevented from coming out by the brake 84 again, and can be rotated by the m-section of the set screw 85. That is, the eccentric round shaft 83 is rotatably supported by the holding frame 60 at the left end side of the holding member 101, 110 in the main scanning direction so as to extend in the sub-scanning direction. In addition, the eccentric round shaft 8
The eccentric small diameter shaft 83c of No. 3 is formed to be eccentric by a predetermined amount with respect to the concentric large diameter shafts 83a and 83d.
Due to the rotation, the left end portion of the writing unit 100 supported by the eccentric small diameter shaft 83C moves up and down, and the LED array 10
The amount of inclination (α) of the optical axis No. 4 in the main scanning direction is finely adjusted. Furthermore, the left support block 131 has pins 144, 146
The rear wall 66 of the holding frame 60 is pulled by the tension spring 145 via the
This causes the concentric round shaft 126 to
An upright round shaft 9 attached to the left bottom wall 70b of the holding frame 60
1 through the left cylindrical cam 92. This left cylindrical cam 92 is rotatably fixed to the upright round shaft 91 by a set screw 93, and when the left cylindrical cam 92 is rotatably adjusted, the photoreceptor drum 3 rotates around the optical axis of the LED array 104.
The amount of inclination (T) of the holding members 101 and 110 with respect to 1 is finely adjusted.

That is, the concentric round shaft 114, 115 and the right cylindrical cam 117
and the left cylindrical cam 134 refers to the LED array holding member 10
A plurality of concentric horizontal axes and eccentric horizontal axes extend parallel to each other in the main scanning direction on both end sides of the main scanning direction of the SLA holding member 1 and the SLA holding member 110, and the eccentric round shafts 80 and 83 extend in the sub scanning direction. holding member 101. to slidably support both horizontal shafts.
The right cylindrical cam 87 and the left cylindrical cam 92 are connected to the holding frame 6 so that they can block the concentric horizontal axes.
The adjustment screw 72, which is an eccentric upright shaft extending in the optical axis direction of the SLA 11l at both ends in the main scanning direction of the writing unit 100, can block the right support block 113. It is a rotary pushing member that is interposed between the holding members 101 and 110 and the holding frame 6o and pushes the holding members 101 and 110 in the main scanning direction with respect to the holding frame 6o.

Next, the effect will be explained.

First, the holding frame 6o is locked in advance by fitting the support shafts 16L and 16R into the conical holes 68a and 69a on one side (rear side) in the sub-scanning direction, and furthermore, the left and right locking arms 64L and 64R are connected to the left and right side plates. 15L and 15R are screwed to locking stands 17L and 17R, and positioned in the optical axis direction (Z direction) of SLA111O.

Next, the holding mechanism 55 determines the installation position and installation posture of the writing unit t-1oo held by the holding frame 6o.
hchi, the image formation position of the LED array 1o4 on the photoreceptor drum 31 by the 5LA 111 is finely adjusted.

First, for example, when the right cylindrical cam 87 and the left cylindrical cam 92 are rotated so that their rotational positions are relatively different, the right end or left end of the writing unit lOO moves in the Y direction, and S
The amount of inclination (γ) of the writing unit 100 relative to the photoreceptor drum 31 is finely adjusted around the optical axis of L A11l, and the 5L
The parallelism between AIII and the axis (or generatrix) of the photoreceptor drum 31 is ensured with high precision.

Furthermore, when the right cylindrical cam 87 and the left cylindrical cam 92 are rotated in the same phase from the predetermined position where the writing unit 100 is positioned in the Y direction, the movement is finely adjusted so that the writing unit 100 is moved in parallel in the sub-scanning direction. Ru.

Note that at this time, the writing unit 100 only horizontally pivots while being supported by the eccentric round shafts 80, 83 extending in the Y direction, and changes in the amount of inclination (α or β) in other directions are prevented.

Next, when one or both of the right cylindrical cam 117 and the left cylindrical cam 134 are rotated, the writing unit 1oO is slightly rotated around the concentric round shafts 116 and 126, and the 5LAAll
The amount of inclination (β) of the lO optical axis in the sub-scanning direction is finely adjusted. Also during this β inclination adjustment, the concentric round shafts 116, 126 at both ends of the writing unit 100 are connected to the left and right cylindrical cams 87, 9
It becomes a rotational fulcrum when it is positioned in the Y direction, and unnecessary displacement can be avoided.

Next, the eccentric round shaft 80 and the eccentric round shaft 83 are rotated relative to each other, and the writing unit gutter 100 is rotated with the eccentric small diameter shafts 80c and 83.
It is tilted by the relative vertical movement of 3c. Shida Rikku,
The amount of tilt (α) of the optical axis of the 5LA 111 in the X direction is adjusted by 'R1. On the other hand, when the eccentric round shafts 80 and 83 rotate in the same phase, the writing unif l-100 moves up and down minute by little while maintaining the same installation posture, and finely adjusts the position of the S L A11l in the optical axis direction (X direction). I can do it. In both cases, the writing unit gutter 100 remains positioned in the X direction by the adjustment screw 72 and the tension spring 129, so unnecessary displacement can be prevented.

In this state, when the writing unit gutter 100 is finely adjusted in the main scanning direction (X direction) by rotating the adjustment screw 72, the writing unit gutter 100 is positioned in the Y and X directions. The robot moves slightly in the X direction, completing a series of fine adjustments to the position and orientation.

In this way, in this embodiment, the left and right cylindrical cams 87.
92, the amount of inclination T or amount of movement in the Y direction of the writing unit 100 is finely adjusted, and the left and right cylindrical cams 117.13
4, the inclination amount β of the writing unit throat lOO is finely adjusted, and the rotation of the eccentric round shaft 80.83 finely adjusts the inclination amount α or two-direction movement amount of the writing unit 100.
By rotating the adjustment screw 72, the amount of movement of the writing unit 100 in the X direction is finely adjusted.

That is, the optical writing of the writing unit 100 onto the photoreceptor drum 31 is performed with high accuracy positional adjustment in the main scanning direction and the sub-scanning direction.
11 in the optical axis direction.

Therefore, the holding mechanism 55 makes it possible to adjust the 5LAIII image formation position on the photoreceptor drum 31 with high precision and with ease, and the 5LAIIIO optical image formed on the photoreceptor drum 31 has a high resolution. At the same time, the perpendicularity between the image line in the sub-scanning direction and the image line in the main scanning direction (raster perpendicularity) is formed with high precision, and there is no blurring or ghosting due to unnecessary light reflection, and the image is high-resolution. An optical writing device 50 is provided that has high positional accuracy of an optically written image and reliably prevents distortion of the written image.

In addition, when the length of the writing unit 100 reaches approximately 1000 mm as in this embodiment, the writing unit 100
If only both ends of the writing unit 100 are held, the writing unit 100
A bending moment due to its own weight acts on the material, causing deflection.
The amount of curvature of the writing unit 100 is, for example, 0.3+a at maximum.
However, in this embodiment, a center beam 103 that also serves as a heat dissipation fin extending in the longitudinal direction is provided on the top of the LED array holding member 101 to improve the bending rigidity. , a finger member 74 is provided above the longitudinal center portion thereof and extends over the front side wall 61 and rear side wall 66 of the holding frame 60, and as the adjustment screw 75 screwed onto the angle 106 advances and retreats, the finger member 74 is moved by the tension springs 77 and 78. The vertical position of the writing unit 100 biased on 74 is finely adjusted. Therefore, it is possible to position the writing unit 100 with high precision in the amount of movement in the X direction even in the central part of the writing unit 100, and to form a high-resolution image over the entire area of the long writing unit (loo). It is also possible to suppress vibrations in the central part of the

On the other hand, in this embodiment, during the above-mentioned positioning and fine adjustment of the posture, the writing unit 100 is attached to the tension springs 119, 121, 136, 1 on the left and right eccentric round shafts 80.83.
37 toward the bottom wall 70 of the holding frame 60, and is positioned with high precision in the X direction at both left and right ends. Therefore, even if thermal expansion occurs in the main scanning direction or sub-scanning direction of the writing unit 100 due to the heat generated by driving the LED array 104, the optical axis of 5LAILL may be displaced in the optical axis direction (X direction), α tilted or β Changes in the amount of inclination are prevented, and the resolution of the written image does not deteriorate.

In addition, writing unit) 100 indicates left and right eccentric round shafts 80.
83 in the X and Y directions, and is biased toward the rear wall 66 of the holding frame 60 by tension springs 142 and 145 so as to move in the X direction without sliding on the cylindrical cams 87 and 92. There is. Therefore, even if the writing unit 100 thermally expands in the main scanning direction, positional deviation in the sub-scanning direction and change in the amount of γ inclination due to this are prevented. Further, since the right support block 113 is urged against the right side wall 68 of the holding frame 6° by the tension spring 129 so as to abut against the adjustment screw 72 and positioned in the X direction, the writing unit 100 is heated in the longitudinal direction. When it expands, the writing unit 100 thermally expands on the left end side with this abutment point as a reference, and if the starting position of optical writing in the main scanning direction is set to the right support block 113 side, the writing starting position will be shifted. This problem is prevented.

In this way, the writing unit 100 is positioned with high precision and is not restricted by the screw fastening force or the like (because it can thermally expand, the unisometric OO will not be distorted during thermal expansion). This allows stable optical writing with high positional accuracy and high resolution.

In addition to these, in this example, L
Heat generated by electrically driving the ED array 104 can be efficiently radiated, and thermal expansion of the writing unit 100 can be reduced. That is, heat radiation fins 102 and a center beam 103 are formed on the upper part of the writing unit 100, and a large amount of heat from the LED array 104 and its drive circuit is blown into the holding frame 60 from these fins 102 and 103. Heat is radiated through the air and released to the outside. Further, since the air guide passages 23, 24 and the nozzles 25, 26 are formed between the holding frame 60 and the writing unit 100, the cooling effect can be enhanced. Furthermore, if the light emitting output of the LED array 104 is small, it is preferable because the amount of heat generated by driving the LED array 104 is small. The distance between the photoreceptor drum 31 must be reduced to some extent, resulting in image loss and a decrease in resolution. However, as described above, the air blown from the air blower 20 causes the nozzle 25.
If it is possible to prevent dust from adhering to the 5LA 111 located between 26 and 26, it is possible to prevent dust from adhering to the light exit surface 111a of the SLA 11l. Deterioration in image quality can be prevented, and high-quality optical writing becomes possible. In addition, by adopting such a dustproof mechanism, the light exit surface 11 of 5LAIII
The cleaning device 1a and the special dustproof mechanism can be omitted, and the displacement of the SLA 11l due to cleaning can be eliminated.

〔effect〕

According to the invention as claimed in claim 1, the light emitting element array and the convergent light transmitting body array are integrally positioned and held at a predetermined relative position by a holding member, and the locking frame is positioned and locked at a predetermined position of the immovable member. In contrast, this holding member has a plurality of concentric horizontal axes and eccentric horizontal axes that are attached to both ends of the holding member in the main scanning direction and extend parallel to each other in the main scanning direction on the both end sides, and a plurality of eccentric horizontal axes that extend in the sub-scanning direction. A plurality of eccentric vertical shafts rotatably supported by the locking frame at both ends of the holding member in the main scanning direction so as to extend and support the concentric horizontal shaft and the eccentric horizontal shaft, and both ends of the locking frame in the main scanning direction. An eccentric upright shaft extending in the optical axis direction of the convergent light transmitting body array at the part, and a rotation that is interposed between the holding member and the locking frame and pushing the holding member in the main scanning direction with respect to the locking frame. Since the position is finely adjusted using the pushing member,
It is possible to prevent displacement of the holding member and the optical transmission body array due to thermal expansion, and it is also possible to prevent deformation of the holding member due to regulation of thermal expansion, and it is possible to reliably prevent distortion of written images. An optical writing device with high resolution and high positional accuracy can be provided.

According to the second aspect of the invention, a Z-direction adjusting screw that moves forward and backward in the optical axis direction of the convergent light transmitting body array is provided at the center of the holding member in the main scanning direction, and the holding member is adjusted by rotating the adjusting screw. Since the amount of movement in the central part in the main scanning direction is finely adjusted, even if the holding member is long, the convergent light transmitter array can be positioned in the optical axis direction over the entire writing width. - can be performed with high precision and high resolution can be obtained.

According to the third aspect of the invention, the concentric horizontal axis and the eccentric horizontal axis are supported on the eccentric vertical axis so as to be slidable in the main scanning direction and the sub-scanning direction, so that the convergent light transmitting body array The amount of movement in the main scanning direction and the sub-scanning direction can be finely adjusted while ensuring high accuracy in the optical axis direction.

[Brief explanation of drawings]

1 to 8 are diagrams showing an embodiment of the optical writing device according to the invention as claimed in claims 1 to 3, and FIG. 1 is a schematic configuration diagram of an electrostatic recording device incorporating the optical writing device, FIG. 2 is a plan view of the main parts of the optical writing device, FIG. 3 is a perspective view of the vicinity of the right end of the locking frame, FIG. 4 is a perspective view of the vicinity of the left end of the locking frame, and FIG. 5 is the same as that of FIG. 6 is a sectional view taken along VI-VI in FIG. 2, and FIG. 7 is a sectional view taken along VI-VI in FIG.
8 is a cross-sectional view taken along the arrow ■-■ in the figure, and FIG. 8 is a cross-sectional view taken along the arrow ■ in FIG. 10... Electrostatic recording device, 15L, 15R... Left and right side plates (immovable members), 3
1...Photoconductor drum (photoconductor), 50...
...optical writing device, 55...holding mechanism, 60...holding frame (locking frame), 72...-adjustment and rotating push member), 75...
...Adjustment screw (Z direction adjustment screw), 80.83...
...Eccentric round shaft (eccentric vertical shaft), 87...Right cylindrical cam (eccentric vertical shaft), 92...Left cylindrical cam (
Eccentric vertical shaft>, 100...Writing unit, 101...LED array holding member (holding member)
, 104...LED array (light emitting element array), 110...SLA holding member (holding member),
111...Selfox lens array (convergent light transmitter array), 114.115...Concentric round axis (concentric horizontal axis), 1
17...Right cylindrical cam (eccentric horizontal axis), 134...
...Left cylindrical cam (eccentric horizontal axis).

Claims (3)

[Claims] (1) A light emitting element array arranged in series in the main scanning direction and blinking controlled by an image signal, a photoreceptor rotatably supported by an immovable member and moving in the sub scanning direction relative to the light emitting element array, and a light emitting element an optical writing device comprising a convergent light transmitter array that forms a light image of the array on a photoreceptor, the light emitting element array and the convergent light transmitter array being integrally positioned and held at predetermined relative positions; a holding member that is positioned and locked at a predetermined position of the immovable member; and a plurality of locking frames that are attached to both ends of the holding member in the main scanning direction and extend parallel to each other in the main scanning direction on the both end sides. The concentric horizontal axis and the eccentric horizontal axis of the holding member extend in the sub-scanning direction so as to be able to block the concentric horizontal axis and the eccentric horizontal axis, and are rotatably supported by the locking frame at both ends of the holding member in the main scanning direction. a plurality of eccentric vertical axes, and an eccentric vertical axis provided at both ends of the locking frame in the main scanning direction so as to be able to block the concentric horizontal axes, and extending in the optical axis direction of the convergent light transmitting body array; a rotary pushing member that is interposed between the holding member and the locking frame and pushes the holding member in the main scanning direction relative to the locking frame; An optical writing device characterized in that the position or posture of the holding frame is finely adjusted by rotating one of the rotating and pushing members. (2) A Z-direction adjustment screw that moves forward and backward in the optical axis direction of the convergent light transmitter array is provided at the center of the holding member in the main scanning direction;
2. The optical writing device according to claim 1, wherein the amount of movement of the central portion of the holding member in the main scanning direction is finely adjusted by rotating the adjustment screw. (3) The optical writing device according to claim 1 or 2, wherein the concentric horizontal axis and the eccentric horizontal axis are slidably supported on the eccentric vertical axis in the main scanning direction and the sub-scanning direction.