JP2011110779A - Optical print head, and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical print head which can keep the fixed interval between a photoreceptor and an optical print head over the main scanning direction and maintain an excellent quality of printing. <P>SOLUTION: The optical print head 3 includes a plurality of light emission heads 10 which have a base member 11, a substrate 12 installed above the base member 11, and a light emitting element array which is installed on the substrate 12 and in which a plurality of light emission elements 14 are arranged in one direction, respectively. A plurality of light emission heads 10 are arranged in the arrangement direction of the light emission element 14. The optical print head has interval adjustment means 17 for adjusting the interval between the base member 11 and the substrate 12, between the base member 11 and the substrate 12, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical print head used as exposure means for an electrophotographic printer or the like, and an image forming apparatus using the optical print head.

  Conventionally, for example, an optical print head such as an LED array head having a large number of light emitting elements arranged is used as an exposure means for an electrophotographic printer or the like. Such an optical print head selectively emits light from a light emitting element based on image data from the outside, and irradiates the light to an external photoconductor via a lens array, and electrostatically strikes the surface of the photoconductor. It has a function of forming a latent image. The electrostatic latent image formed on the photoconductor becomes a toner image through a process such as development, and the recording paper is recorded by transferring and fixing the toner image onto the recording paper.

  As such an optical print head, a plurality of light emitting heads each having a plurality of light emitting elements mounted on a circuit board are arranged along the main scanning direction, and adjacent light emitting heads are shifted in the sub scanning direction to form a staggered pattern. An arrangement has been proposed (see, for example, Patent Document 1). This optical print head is used when printing on a relatively large recording medium such as an A0 size paper.

JP 2001-328292 A

  However, since the optical print head described above has a long length in the main scanning direction, a deviation in the roundness of the photoconductor in the main scanning direction and a deflection due to the weight of the optical print head are likely to occur. In some cases, it is difficult to keep the distance between the photosensitive member and the optical print head constant over the entire length. In such a case, there has been a problem that the focal length of the light emitted from the light emitting element is changed and the printing quality is deteriorated.

  Therefore, there is a need for an optical print head that can maintain a constant interval between the photosensitive member and the optical print head in the main scanning direction and maintain a good print quality, and an image forming apparatus using the same.

  An optical print head according to an aspect of the present invention includes a base member, a substrate provided above the base member, a light emitting element array provided on the substrate, and a plurality of light emitting elements arranged in one direction. Are provided with a plurality of light emitting heads. The plurality of light emitting heads are arranged along an arrangement direction of the light emitting elements. A distance adjusting means for adjusting a distance between the base member and the substrate is provided between the base member and the substrate.

  An image forming apparatus according to an aspect of the present invention includes: the optical print head; a photoconductor disposed to face the light emitting element array of the optical print head; a memory storing predetermined data; and the memory And a control unit that controls adjustment by the interval adjusting unit based on the stored data.

  According to the optical print head of one aspect of the present invention, it is possible to realize an optical print head that can maintain a good print quality by keeping the distance between the photoconductor and the optical print head constant in the main scanning direction. it can.

  According to the image forming apparatus of one aspect of the present invention, it is possible to realize an image forming apparatus that can maintain good print quality.

1 is a diagram illustrating a configuration example of an image forming apparatus using an optical print head according to an embodiment of the present invention. It is a figure which shows the structural example of an LED head, (a) is a top view, (b) is a perspective view in the area | region A of (a), (c) is sectional drawing in the B1-B1 line of (b). It is sectional drawing in the B2-B2 line | wire of FIG.2 (b). It is a figure which shows the modification of the cross section in the B2-B2 line | wire of FIG.2 (b). It is a figure which shows the structural example of a space | interval adjustment means, (a) is a top view, (b) is sectional drawing in the AA of (a). It is a figure for demonstrating the effect | action of the space | interval adjustment means of FIG. 1 is a schematic diagram illustrating a configuration example of an image forming apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a schematic configuration and function of an example of the image forming apparatus of the present invention will be described. An image forming apparatus M shown in FIG. 1 includes an electrophotographic photosensitive member (hereinafter also simply referred to as “photosensitive member”) 1, a charging device 2, an LED head unit (optical print head) 3, a developing device 4, and a transfer device 5. , A fixing device 6, a cleaning device 7, and a static elimination device 8.

  The electrophotographic photosensitive member 1 forms an electrostatic latent image and a toner image based on an image signal, and is rotatable in the direction of arrow A in FIG. The electrophotographic photoreceptor 1 is obtained by forming a photosensitive layer 11 on the outer peripheral surface of a cylindrical substrate 10. The cylindrical substrate 10 has conductivity at least on its surface, and is formed of, for example, aluminum.

  The photosensitive layer 11 has a structure in which a photoconductive layer made of an inorganic semiconductor such as amorphous silicon or an organic semiconductor is deposited. The specific resistance of the layer is rapidly reduced to form a predetermined latent image on the photoconductive layer. The photosensitive layer 11 may also be provided with a carrier injection blocking layer for blocking carrier injection from the cylindrical substrate 10 and a surface layer for protecting the surface of the electrophotographic photoreceptor 1.

  The charging device 2 is for charging the surface of the electrophotographic photoreceptor 1 uniformly to a positive polarity or a negative polarity according to the type of the photoconductive layer. The charging potential of the electrophotographic photosensitive member 1 is usually 200 to 1000V.

  The optical print head 3 irradiates the surface of the electrophotographic photosensitive member 1 (photosensitive layer 11) with light in accordance with an image signal in order to form an electrostatic latent image on the surface of the electrophotographic photosensitive member 1. The optical print head 3 is disposed substantially parallel to the electrophotographic photosensitive member 1 so as to be separated by a predetermined distance. The detailed configuration of the optical print head 3 will be described in detail later. A connector 91 connected to the control means 9 of the image forming apparatus M is connected to the optical print head 3. The optical print head 3 receives an image signal transmitted from the control means 9 of the image forming apparatus M from the connector 91 and emits light according to the image signal.

  The control unit 9 is a part that controls the operation of the entire image forming apparatus M, and is constituted by a computer having a CPU, a memory, and the like (not shown). The control unit 9 converts an image signal input from the outside of the apparatus M into a signal for driving the optical print head 3 and outputs the signal to the optical print head 3 via the connector 91. In the present specification, an image signal input from the outside and a signal for driving the optical print head 3 are not particularly distinguished and described (all are described as image signals). The control means 9 is also connected to other parts of the apparatus M (the electrophotographic photosensitive member 1, the charging device 2, the developing device 4, the transfer device 5, the fixing device 6, the cleaning device 7, the static eliminating device 8, etc.). The operation of each unit in the image forming process is controlled. The control means 9 includes an operation information receiving means (not shown) such as a mouse or a keyboard, an image signal receiving means such as a CD-ROM drive or a modem. The control unit 9 controls the operation of each unit according to an operation instruction and an image signal received from the outside, and forms an image according to the received image signal.

  The developing device 4 shown in FIG. 1 is for developing an electrostatic latent image on the electrophotographic photosensitive member 1 to form a toner image. The developing device 4 holds a developer and includes a developing sleeve 40. The developer is for constituting a toner image formed on the surface of the electrophotographic photoreceptor 1, and is triboelectrically charged in the developing device 4. As the developer, a two-component developer composed of a magnetic carrier and an insulating toner or a one-component developer composed of a magnetic toner can be used.

  The developing sleeve 40 conveys the developer to the developing area between the electrophotographic photosensitive member 1 and the developing sleeve 40. In the developing device 4, the toner frictionally charged by the developing sleeve 40 is conveyed in the form of a magnetic brush adjusted to a constant spike length, and this toner is used in the developing area between the electrophotographic photosensitive member 1 and the developing sleeve 40. The electrostatic latent image is developed to form a toner image.

  The transfer device 5 is for transferring a toner image onto a recording paper P fed to a transfer region between the electrophotographic photosensitive member 1 and the transfer device 5, and includes a transfer charger 50 and a separation charger 51. I have. In the transfer device 5, the back surface (non-recording surface) of the recording paper P is charged with a polarity opposite to that of the toner image in the transfer charger 50, and the electrostatic charge between the charged charge and the toner image causes the recording paper P to be charged. The toner image is transferred. In the transfer device 5, simultaneously with the transfer of the toner image, the back surface of the recording paper P is AC-charged in the separation charger 51, and the recording paper P is quickly separated from the surface of the electrophotographic photoreceptor 1.

  The fixing device 6 is for fixing the toner image transferred to the recording paper P, and includes a pair of fixing rollers 60 and 61. In the fixing device 6, the toner image is fixed to the recording paper P by heat, pressure, or the like by passing the recording paper P between the pair of rollers 60 and 61. In the image forming apparatus M, an image is recorded on the recording paper P in this way.

  The cleaning device 7 is for removing toner remaining on the surface of the electrophotographic photoreceptor 1, and includes a cleaning blade 70. In the cleaning device 7, the toner remaining on the surface of the electrophotographic photosensitive member 1 is scraped and collected by the cleaning blade 70. The toner collected in the cleaning device 7 may be recycled into the developing device 4.

  The static eliminator 8 is for removing the surface charge of the electrophotographic photosensitive member 1. The static eliminator 8 is configured to remove surface charges of the electrophotographic photosensitive member 1 by, for example, light emission. By the operation of the cleaning device 7 and the charge removal device 8, the surface state of the electrophotographic photosensitive member 1 is reset to the initial state (that is, the toner is not attached and is not charged). The image is sent to the fixing device 6 and image formation is performed again. In this manner, the image forming apparatus M forms and records an image on the continuously supplied recording medium P.

  Hereinafter, the optical print head 3 which is an example of the optical print head of the present invention will be described in more detail.

  2A and 2B are diagrams illustrating a configuration example of the optical print head 3, in which FIG. 2A is a top view, FIG. 2B is a perspective view in a region A in FIG. 2A, and FIG. 2C is a B1-B1 line in FIG. FIG. FIG. 3 is a sectional view taken along line B2-B2 in FIG. As shown in FIG. 2A, the optical print head 3 has a plurality of light emission heads 10. These light emitting heads 10 are arranged along the main scanning direction. Further, end portions in the main scanning direction of the plurality of light emitting heads 10 are arranged so as to overlap in the sub scanning direction. Here, the main scanning direction is the direction perpendicular to the paper surface in FIG. 1 and the left-right direction in FIG. The sub-scanning direction is a direction perpendicular to both the main scanning direction and the light emitting direction from the light emitting head 10 (indicated by an arrow in FIG. 1), and is the vertical direction in FIG. is there.

  As shown in FIGS. 2 and 3, the light emitting head 10 includes a base member 11 and a substrate 12 provided on the base member 11. The substrate 12 includes a base substrate 12a and a circuit substrate 12b provided on the base substrate 12a. On the circuit board 12b, a driver IC 13 and a light emitting element 14 electrically connected to a wiring (not shown) provided on the circuit board 12b are provided. A lens folder 15 is attached to the circuit board 12b. A rod lens array 16 is attached to the lens folder 15. The rod lens array 16 has a plurality of rod lenses that transmit light emitted from the light emitting element 14 and form an image at a predetermined position. Further, the light emitting head 10 includes a gap adjusting unit 17 that adjusts a gap between the base member 11 and the base substrate 12a, that is, a gap between the base member 11 and the substrate 12, between the base member 11 and the base substrate 12a. . The spacing adjusting means 17 is provided at both ends of each light emitting head 10 in the main scanning direction.

  The base substrate 12a has an L-shaped cross section perpendicular to the main scanning direction. Specifically, it has a flat plate-like first portion on which the circuit board 12b is mounted, and a second portion that forms an angle perpendicular to the first portion. The interval adjusting means 17 is provided between the base member 11 and the first portion of the base substrate 12a.

  A plurality of light emitting elements 14 are arranged along the main scanning direction on the upper surface of the circuit board 12b. Although not shown, specifically, one or more light emitting element arrays in which a plurality of light emitting elements are arranged in one direction are arranged in the main scanning direction on the upper surface of the circuit board 12b. Here, “arranged along one direction” does not only refer to a case where they are arranged linearly along one direction, but also includes a case where they are arranged in a staggered manner along one direction.

  The distance adjusting means 17 provided between the base member 11 and the base substrate 12b varies in length in a direction perpendicular to both the main scanning direction and the sub-scanning direction. Thereby, the space | interval between the base member 11 and the circuit board 12a is adjusted.

  As shown in FIG. 3, long holes 18 extending in the direction (Z direction) perpendicular to the main scanning direction and the sub-scanning direction are provided at both ends of the base substrate 12b in the main scanning direction. Specifically, the long hole 18 is provided in the second portion of the base substrate 12a. The opening of the long hole 18 is located on the surface of the base substrate 12b facing the base member 11. A pin member 19 is inserted into the long hole 18. One end of the pin member 19 is fixed to the base member 11. When the length in the Z direction of the distance adjusting means 17 changes, the base substrate 12 b can move along the pin member 19 with respect to the base member 11. There is a gap (not shown) between the pin member 19 and the inner wall of the long hole 18. As a result, the base substrate 12b can be inclined with respect to the base member 11 when the length of the distance adjusting means 17 is different at both ends in the main scanning direction.

  The base member 11, the base substrate 12a, and the pin member 19 are each made of, for example, aluminum.

  Moreover, as shown in FIG. 4, the base member 11 and the base substrate 12a may each have an L-shaped cross section perpendicular to the main scanning direction. In this case, the base member 11 and the base substrate 12a are combined with each other so that one L-shape and the other L-shape obtained by rotating the L-shape by 180 degrees are connected in a cross section perpendicular to the main scanning direction. May be.

  In the case of the configuration shown in FIG. 4, the length of the long hole 18 and the pin member 19 can be increased compared to the configuration shown in FIG. 3, so that the amount of movement of the base substrate 12 b relative to the base member 11 is increased. can do. As a result, the adjustment range of the interval between the base member 11 and the base substrate 12b can be further increased.

  The interval adjusting unit 17 is, for example, a piezoelectric element. By applying a voltage to the piezoelectric element, the piezoelectric element expands and contracts, and the distance between the base substrate 12b and the base member 11 can be adjusted.

  When the distance adjusting means 17 is a piezoelectric element, an electrode is provided at the end of the piezoelectric element in the direction in which the piezoelectric element expands and contracts, that is, the Z direction. These electrodes are in contact with the base member 11 and the base substrate 12a. In addition, when the base member 11 and the base substrate 12a have conductivity, it is necessary to perform a process such as covering an area where the electrodes of the piezoelectric element are in contact with an insulating film. Further, in order to insulate the wiring connected to the electrode of the piezoelectric element and the base member 11 or the base substrate 12a, an insulating layer is formed in a portion where the base member 11 or the base substrate 12a is in contact. For example, when the base member 11 or the base substrate 12a is made of aluminum, the insulating treatment may be performed by partially performing alumite treatment.

  Furthermore, a wiring board (hereinafter referred to as “driving wiring board”) used for driving the piezoelectric element may be provided on the upper surface of the base substrate 12a where the light emitting element 14 is provided or on the side surface of the base member 11. . In this case, the electrode of the piezoelectric element is connected to an external power source via, for example, a wiring that passes through the inside of a through hole that penetrates the base member 11 or the base substrate 12a. In this case, the inner peripheral surface of the through hole penetrating the base member 11 or the base substrate 12a is kept insulative by performing alumite treatment or the like. The power source may be provided in the control means 9 in FIG.

  Moreover, the space | interval adjustment means 17 may be a member which can be expanded-contracted to an up-down direction, for example. As shown in FIG. 5, the interval adjusting means 17 includes a support portion 20 provided between the base member 11 and the base substrate 12 b, and a rectangular movable portion 21 attached to the support portion 20. The movable portion 21 has a first end T1 and a second end T2 located on both sides of the support portion 20. The first end portion T1 and the second end portion T2 are displaced in the Z direction with the support portion 20 as a fulcrum. That is, the movable portion 21 operates like a so-called seesaw in which both end portions T1 and T2 move up and down with the support portion 20 as a fulcrum.

  Here, the support part 20 and the movable part 21 are accommodated in the housing B. The housing B is provided on the upper surface of the base member 11 (the surface facing the base substrate 12b). An opening H is provided on the upper surface of the housing B. The first end T1, which is one end of the movable portion 21, is displaced in the Z direction while protruding from the opening H. On the other hand, the second end T2 of the movable portion 21 is displaced in the Z direction inside the housing B. The support portion 20 has a rod shape, and both end portions thereof are attached to the side surface of the housing B. Here, the housing | casing B consists of resin, for example, and the support part and the movable part 21 consist of metals, for example.

  A straight line connecting the first end portion T1 and the second end portion T2 (longitudinal direction of the movable portion 21) is parallel to the main scanning direction, and the longitudinal direction of the support portion 20 is parallel to the sub-scanning direction. is there. However, if the first end portion T1 and the second end portion T2 are displaced vertically in the Z direction, the longitudinal direction of the movable portion 21 is parallel to the sub-scanning direction, and the longitudinal direction of the support portion 20 is the main scanning direction. It may be parallel.

  The interval adjusting means 17 has a piezoelectric element 22 that expands and contracts in the Z direction. One end portion (upper end portion in the Z direction) of the piezoelectric element 22 is fixed to the inner surface of the housing B, and the other end portion (lower end portion in the Z direction) is the second end of the movable portion 21. It is fixed to the part T2. At this time, when the piezoelectric element 22 expands, the distance between the inner surface of the housing B and the second end T2 of the movable portion 21 increases, and a pressing force is applied to the second end T2 from above. When the pressing force is applied to the second end portion T2, the movable portion 21 displaces the first end portion T1 upward along the Z direction according to the principle of the lever with the support portion 20 as a fulcrum. lift. A portion of the base substrate 12b that contacts the first end T1 is displaced upward along the Z direction.

  On the other hand, when the piezoelectric element 22 contracts, the pressing force applied from above to the second end T2 of the movable portion 21 decreases, and the second end T2 is displaced upward along the Z direction. Then, according to the displacement of the second end T2, the first end T1 is displaced downward along the Z direction. As a result, the portion of the base substrate 12b that contacts the first end T1 is displaced downward along the Z direction, and the distance between the base member 11 and the base substrate 12b is reduced. Note that the distance between the support portion 20 and the second end portion T2 is preferably smaller than the distance between the support portion 20 and the first end portion T1.

  In addition, a spring portion 23 is provided on the opposite side of the piezoelectric element 22 with respect to the second end T2 of the movable portion 21 in the Z direction. The spring portion 23 is connected to the second end T2 of the movable portion 21. A pressing force is applied from the piezoelectric element 22 to the second end portion T <b> 2 of the movable portion 21, and a reaction force is applied from the spring portion 23. Thereby, the first end T2 is stably fixed at a position corresponding to the amount of expansion / contraction of the piezoelectric element 22.

  An electrode is connected to the surface of the piezoelectric element 22. As described above, these electrodes may be connected to an external power source via wiring. This power source may be provided in the control means 9 of FIG.

  In the above description, the first end T1 of the movable portion 21 is attached to the base substrate 12b, but may be attached to the base member 11. In this case, the housing B is provided on the back surface (the surface facing the base member 11) of the base substrate 12 b, and the opening H of the housing B is positioned facing the base member 11. Then, the base member 11 is displaced in the Z direction by displacing the first end T1 of the movable body 21 in the Z direction.

  According to the configuration shown in FIG. 5, even if the extension amount of the piezoelectric element 22 is small, the distance between the base member 11 and the base substrate 12 b can be increased using the movable portion 21. According to this configuration, the amount of voltage applied to the piezoelectric element 22 can be reduced, and as a result, power consumption can be reduced.

  Specifically, due to the expansion / contraction of the piezoelectric element 22, the amount of variation in thickness in the expansion / contraction direction is about 10 μm, but according to the configuration of FIG. 5, the amount of variation can be increased from about 50 μm to about 100 μm.

  FIG. 6 is a diagram for explaining the operation of the interval adjusting unit 17 when the configuration of FIG. 5 is used as the interval adjusting unit 17. Here, the base member 11 and the board | substrate 12 shall have the structure shown in FIG. In order to explain the movement of the base substrate 12a relative to the base member 11, a part of the base substrate 12a and the pin member 19 which are not present in the cross section shown in FIG. 6 are indicated by dotted lines. As shown in FIG. 6, the length of the circuit board 12b on which the light emitting element 4 is mounted is changed by changing the length between the base member 11 and the substrate 12 at both ends of the light emitting head 10 in the main scanning direction. Can be tilted with respect to the horizontal direction. Therefore, for example, even when the roundness of the photoconductor 1 in the main scanning direction is different, the surface of the photoconductor 1 and the light emitting head are inclined by tilting the surface of the circuit board 12b from the horizontal direction in accordance with the deviation of the roundness. The distance between the two can be kept constant. In addition, since the distance between the surface of the photosensitive member 1 and the light emitting head 10 can be kept constant for each light emitting head 10, the optical print head 3 in which the light emitting heads 10 are arranged in the main scanning direction and the photosensitive member. The distance from the body 1 can also be kept constant. Since the distance between the surface of the photosensitive member 1 and the light emitting head 10 can be adjusted for each light emitting head 10, for example, the roundness of the photosensitive member 1 is locally deviated in the main scanning direction. The distance between the surface of the photosensitive member 1 corresponding to the part and the light emitting head 10 can be adjusted.

  In FIG. 6 and the like, the distance adjusting means 17 is provided at both ends of the light emitting head 10 in the main scanning direction, but the distance adjusting means 17 may be provided at one end and a spacer may be provided at the other end. Good. In that case, the distance between the surface of the photosensitive member 1 and the light exit head at the other end is kept constant, and only the above-mentioned distance at one end is adjusted.

  Note that the roundness of the photoconductor 1 in the main scanning direction and the deflection due to the weight of the optical print head 3 can be measured in advance before the image forming apparatus M is assembled. For example, in terms of roundness, the position data of a portion of the photoconductor 1 where the roundness is deviated and the position in the Z direction of the surface or the amount of displacement in the Z direction when the photoconductor 1 is rotated ( Data such as a deviation amount) is stored in a memory. After the optical print head 1 is assembled, the operation is performed while measuring the rotation angle of the photoreceptor 1. The position data stored in the memory is read according to the rotation angle, and the interval adjusting means 17 is controlled according to the position data. Thereby, the distance between the photoconductor 1 and the light emitting element 14 can be changed according to the roundness of the photoconductor 1.

  Specifically, as shown in FIG. 7, the image forming apparatus M includes a measuring device 30 that measures the rotation angle of the photosensitive member 1, a memory 31 that stores position data, and an interval adjustment according to the position data. And a control unit 32 for controlling the means 17. When the distance adjusting unit 17 changes the distance between the base member 11 and the base substrate 12b due to expansion and contraction of the piezoelectric element, the control unit 32 changes the value of the voltage applied to the piezoelectric element and outputs it. . The measuring device 30, the memory 31, and the control unit 32 may be included in the control unit 9 in FIG.

  Similarly, regarding the deflection due to the weight of the optical print head 3, the position data of the bent portion of the optical print head 3 and data such as the amount of deflection corresponding to the usage time in the portion are stored in the memory 31. After assembling the image forming apparatus M, the control unit 32 reads out position data and data such as a deflection amount stored in the memory 30 according to the usage time, and the interval adjusting unit 17 according to the data. To control. Thereby, the distance between the photoreceptor 1 and the light emitting element 14 can be changed according to the deflection of the optical print head 3. In this case, the measuring device 31 in FIG. 7 may be omitted.

  Further, not only the roundness of the photoconductor 1 and the deflection due to the light weight of the head 3 but also the data of the focal depth of the rod lens array 16 of each light emitting head 10 may be measured in advance. That is, even when the focal depth varies depending on the lenses constituting the rod lens array 16, the distance between the photosensitive member 1 and the light emitting element 14 can be controlled according to the focal depth of the lens. The interval adjusting means 17 may be controlled by combining data. For example, the optimal value of the distance between the photosensitive member 1 and the light emitting element 14 is calculated for each light emitting head 10 by combining the circularity data of the photosensitive member 1 and the focal depth data of the rod lens array 16. The interval adjusting means 17 may be controlled according to the calculated value.

  Furthermore, according to the configuration of the optical print head according to the present embodiment, after assembling the image forming apparatus M, the deviation of the roundness of the photosensitive member 1 and the deflection due to the weight of the optical print head 3 are measured. The distance between the photosensitive member 1 and the light emitting element 14 can be changed by controlling the interval adjusting means 17 based on the measured value.

  Further, even after the image forming apparatus M is assembled, even when the state of the external environment such as temperature changes, for example, by controlling the interval adjusting unit 17 according to the change, the photosensitive member 1 and the light emitting element 14 can be controlled. The distance between can be changed. Thereby, for example, even when the substrate 12 of each light emitting head 10 is deformed due to a temperature change, the distance between the photosensitive member 1 and the light emitting element 14 can be kept constant over the main scanning direction.

3 LED head unit 10 Light emitting head 11 Base member 12a Base substrate 12b Circuit substrate 13 Driver IC
14 Light emitting element 15 Lens folder 16 Rod lens array 17 Spacing adjustment means

Claims (6)

Provided with a plurality of light emitting heads each including a base member, a substrate provided above the base member, and a light emitting element array provided on the substrate and arranged with a plurality of light emitting elements along one direction. An optical print head,
The plurality of light emitting heads are arranged along the arrangement direction of the light emitting elements, and a gap adjusting unit that adjusts a gap between the base member and the substrate between the base member and the substrate. Each with an optical print head.   Each of the light emitting heads has a plurality of the distance adjusting means provided at both ends in the arrangement direction, and the plurality of the distance adjusting means between the base member and the substrate at the both ends. The optical print head according to claim 1, wherein the interval is adjusted. The interval adjusting means has a support part provided between the base member and the substrate, and a movable part attached to the support part,
The movable part is located on both sides of the support part, and has a first end part and a second end part that are displaced vertically with the support part as a fulcrum, and the first end part is the base member Or attached to the substrate,
3. The optical print head according to claim 1, wherein a portion of the base member or the substrate that contacts the first end portion is displaced in the vertical direction according to the displacement of the first end portion. Having a piezoelectric element attached to the second end;
The second end portion is displaced according to expansion and contraction of the piezoelectric element in the vertical direction,
The optical print head according to claim 3, wherein the first end portion is displaced in the vertical direction in accordance with a displacement of the second end portion. An optical print head according to any one of claims 1 to 4,
A photoconductor disposed to face the light emitting element array of the optical print head;
A memory in which predetermined data is stored;
An image forming apparatus comprising: a control unit that controls adjustment by the interval adjustment unit based on data stored in the memory. It has a sensor that measures the state of the external environment,
The image forming apparatus according to claim 5, wherein the memory stores data corresponding to an output of the sensor.

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