JP2010123875A - Optical component holder, optical sensor and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical component holder fixing the direction of an optical axis by adjusting a deviation of the optical axis in an optical component, and also to provide an optical sensor with the optical component holder, and an image forming apparatus with the optical sensor. <P>SOLUTION: An optical component holder for holding a bullet-shaped optical component comprises: a case 71; a housing hole 72 provided in the case 71; a first holding member 74 provided inside the housing hole 72 for holding a head of the optical component; and a second holding member 75 provided inside the housing hole 72 away from the first holding member 74 for holding a body of the optical component. The second holding member 75 includes a plurality of protruding portions protruded along a circumferential direction of the housing hole 72 separately from each other. The plurality of protruding portions are used as movable protruding portions 76 changeable with the amount of protrusion from an inner surface 72a of the housing hole 72, and by changing the amount of protrusion of each protruding portion, the body of the optical component is moved orthogonally to an axis of the housing hole 72. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical component holder used for holding an optical component such as a so-called bullet-shaped light emitting diode, photodiode, or phototransistor, an optical sensor including the optical component holder, and an image including the optical sensor. The present invention relates to a forming apparatus.

  An optical system for holding a so-called shell-shaped optical component having a hemispherical head and a cylindrical barrel connected to the head to fix the optical component to a printed wiring board or the like. A component holder is used. As an example of such an optical component holder, Patent Document 1 proposes an LED holder used for holding a bullet-type light emitting diode (LED).

The LED holder proposed in Patent Document 1 is positioned on both sides of the light-emitting diode body and the U-shaped walls that surround both sides and the back of the light-emitting diode body (that is, the surface from which the lead wire protrudes). Provided on one of the walls to be inserted, and a flange provided on the rear side end of the light emitting diode to prevent erroneous insertion by being inserted, and a wall located on the back of the light emitting diode body. And a pair of concave slits into which the pair of lead wires of the light emitting diode are inserted. The light emitting diode is held by the LED holder, so that the body of the light emitting diode is made parallel to the printed wiring board, and the leg (lead wire) of the light emitting diode is bent perpendicularly from the slit to the printed wiring board. Then, it is inserted into the insertion hole of the printed wiring board and fixed to the printed wiring board. Therefore, according to this LED holder, since the body of the light emitting diode is made parallel to the printed wiring board, the irradiation angle of the light emitting diode can be kept constant and the irradiation range can be made uniform.
Japanese Patent Laid-Open No. 2005-311102

  The bullet-type light emitting diode as described above is constructed by sealing a light emitting element as an optical element connected to a lead wire with a sealing member such as a transparent epoxy resin, and is manufactured at a relatively low cost. it can. However, such a bullet-type light emitting diode has low manufacturing accuracy such as the position of the light emitting element and the lens shape provided on the head, and originally the axis of the body of the light emitting diode and the central axis of the irradiation light of the light emitting diode ( That is, where the optical axis) should match, a shift (that is, a shift of the optical axis) may occur in them. And when a light emitting diode is held using the above-mentioned LED holder, a light emitting diode having no optical axis deviation can be irradiated at a desired irradiation angle, but a light emitting diode having an optical axis deviation is desired. There is a problem that the irradiation light quantity changes because the direction of the optical axis is not constant. In addition, when the LED holder described above is used to hold other types of optical components such as a bullet-type photodiode or phototransistor, there is a similar problem.

  In addition, in image forming apparatuses such as copiers, printers, and facsimiles using an electrophotographic system, the amount of toner adhering (the amount of powder adhering) to the surface of an image carrier such as a photoreceptor or an intermediate transfer member is optically detected. The image density is adjusted by detection using a means, and as the optical detection means, an optical sensor including the above-described bullet-type light emitting diode and photodiode is used. And when the light emitting diode and the photodiode included in the optical sensor are held by the LED holder described above, the irradiation light amount of the light emitting diode and the received light amount of the photodiode are not constant, and an error occurs in the detection of the toner adhesion amount, There has been a problem that the image density cannot be adjusted accurately.

  The present invention aims to solve the above problems. That is, the present invention relates to an optical component holder that can adjust the optical axis shift in the optical component to make the direction of the optical axis constant, an optical sensor that includes the optical component holder, and an image formation that includes the optical sensor. The object is to provide a device.

  In order to achieve the above object, the invention described in claim 1 is an optical component holder for holding a bullet-shaped optical component, wherein an inner diameter formed larger than an outer diameter of a case and a barrel portion of the optical component. A first hole provided on the inner surface of the receiving hole, the receiving hole provided through the case, and a fulcrum portion projecting annularly over the circumferential direction of the inner surface of the receiving hole. A holding member and a plurality of three or more projecting portions projecting away from each other along the circumferential direction of the inner surface of the housing hole, the first surface along the axial direction of the housing hole on the inner surface of the housing hole A second holding member provided apart from the holding member, and the fulcrum portion is formed such that a surface surrounded by an inner edge of the fulcrum portion is included in a transverse section of the body portion of the optical component. And the plurality of protrusions protrude from the inner surface of the receiving hole. It is an optical component holder, characterized in that there is a change freely movable protrusion amount.

  According to a second aspect of the present invention, in order to achieve the above object, in an optical component holder for holding a bullet-shaped optical component, an inner diameter formed larger than an outer diameter of a case and a barrel portion of the optical component An inner surface of the housing hole provided through the case, and having three or more fulcrum portions protruding away from each other along a circumferential direction of the inner surface of the housing hole And a shaft of the accommodation hole on the inner surface of the accommodation hole having a first holding member and three or more projecting portions that project away from each other along the circumferential direction of the inner surface of the accommodation hole. A second holding member provided apart from the first holding member along the direction, and the plurality of fulcrum portions have a surface surrounded by the tips thereof beside the body portion of the optical component. The plurality of protrusions are configured to be included in the directional cross section, and Part is an optical component holder, characterized in that there is a change freely movable projecting portion projecting amount from the inner surface of the accommodation hole.

  The invention described in claim 3 is the invention described in claim 1 or 2, wherein the movable projecting portion is provided through the inner surface of the housing hole and the outer surface of the case; And a movable element that can be projected and retracted at an opening on the inner surface side of the accommodation hole in the through hole.

  The invention described in claim 4 is characterized in that, in the invention described in claim 3, the length of the movable element is shorter than the length of the through hole.

  The invention described in claim 5 is the invention described in claim 3 or 4, wherein a thread groove is provided on the inner peripheral surface of the through hole, and the outer peripheral surface of the mover A screw thread to be screwed into the screw groove provided on the inner surface of the through hole is provided.

  The invention described in claim 6 is the invention described in any one of claims 3 to 5, wherein the optical component is held by the first holding member and the second holding member. A fixing member for fixing the mover to the through hole is provided.

  The invention described in claim 7 is the invention described in any one of claims 1 to 6, wherein at least one of the plurality of protrusions is elastic instead of the movable protrusion. It is characterized by the fact that it is an elastic projecting portion composed of a body.

  The invention described in claim 8 is an optical sensor comprising an optical component and an optical component holder for holding the optical component, and as the optical component holder, the optical component holder according to any one of claims 1 to 7. An optical sensor comprising the optical component holder described.

  The invention described in claim 9 includes at least an image carrier on which powder is adhered to a surface, and an optical sensor for detecting the amount of the powder adhered to the surface of the image carrier. An image forming apparatus comprising the optical sensor according to claim 8 as the optical sensor.

  According to the first aspect of the present invention, the first holding member having the fulcrum portion that is annularly projected over the circumferential direction of the inner surface of the accommodation hole is provided, and the fulcrum portion is surrounded by the inner edge thereof. Since the curved surface is formed so as to be included in the lateral cross section of the barrel of the optical component (that is, the cross section orthogonal to the axial direction of the barrel), when the optical component is inserted into the receiving hole, The head of the component abuts against the fulcrum portion, and movement in the insertion direction is restricted, and the head of the optical component is held on the inner edge of the fulcrum portion. Further, a second holding member having three or more projecting portions protruding away from each other along the circumferential direction of the inner surface of the receiving hole is provided apart from the first holding member along the axial direction of the receiving hole. Therefore, the body portion of the optical component is held by the plurality of protrusions. And since these several protrusion part is made into the movable protrusion part which can change the protrusion amount from the inner surface of an accommodation hole, by changing the protrusion amount of a movable protrusion part, a fulcrum part is used as a fulcrum of an optical component. The position of the body portion can be moved with respect to the direction orthogonal to the axial direction of the receiving hole, so that the optical axis of the optical component can be moved, and the optical axis deviation in the optical component can be adjusted to adjust the light. The axis direction can be made constant.

  According to the invention described in claim 2, the first holding member having three or more fulcrum portions protruding apart from each other along the circumferential direction of the inner surface of the accommodation hole is provided. The fulcrum portions of the optical component are formed so that the surface surrounded by the tip of the fulcrum portion is included in the lateral cross section of the barrel portion of the optical component. The part abuts on the fulcrum part to restrict movement in the insertion direction, and the head of the optical component is held between the tips of the plurality of fulcrum parts. Further, a second holding member having three or more projecting portions protruding away from each other along the circumferential direction of the inner surface of the receiving hole is provided apart from the first holding member along the axial direction of the receiving hole. Therefore, the body portion of the optical component is held by the plurality of protrusions. And since these several protrusion part is made into the movable protrusion part which can change the protrusion amount from the inner surface of an accommodation hole, by changing the protrusion amount of a movable protrusion part, a fulcrum part is used as a fulcrum of an optical component. The position of the body portion can be moved with respect to the direction orthogonal to the axial direction of the accommodation hole, so that the optical axis of the optical component can be moved, and the deviation of the optical axis in the optical component is adjusted, The direction of the optical axis can be made constant. In addition, since the contact area between the head of the optical component and the fulcrum portion can be reduced, the position of the barrel of the optical component can be moved smoothly, and the optical axis shift of the optical component can be adjusted with high accuracy.

  According to the invention described in claim 3, the movable protrusion projects into the through hole provided through the inner surface of the housing hole and the outer surface of the case, and the opening on the inner surface side of the housing hole in the through hole. And the movable part can be adjusted, the amount of protrusion from the inner surface of the housing hole can be changed by adjusting the position of the movable part from the outside of the case. The deviation can be adjusted easily. In addition, since the configuration is simple, an optical component holder that can adjust the deviation of the optical axis in the optical component can be provided at low cost.

  According to the invention described in claim 4, since the length of the mover is shorter than the length of the through hole, when the mover protrudes from the inner surface of the accommodation hole, the mover protrudes from the outer surface of the case. For example, it is possible to prevent the position of the optical component from changing due to contact with the movable element at the time of assembly or the like, and it is possible to prevent the optical axis from being shifted in the optical component.

  According to the fifth aspect of the present invention, a thread groove is provided on the inner peripheral surface of the through hole, and a screw thread is provided on the outer peripheral surface of the mover on the inner surface of the through hole. Since the screw threads to be combined are provided, the movable protrusion is configured by a screw structure, and therefore, the shift of the optical axis in the optical component can be adjusted more easily.

  According to the invention described in claim 6, since the optical member is held by the first holding member and the second holding member, the fixing member that fixes the movable element to the through hole is provided. After adjusting the optical axis of the component, the mover can be fixed to the through hole by the fixing member, so that the position of the optical component can be prevented from changing, and the optical axis of the optical component after the optical axis adjustment is adjusted. Misalignment can be prevented.

  According to the invention described in claim 7, since at least one of the plurality of protrusions is an elastic protrusion formed of an elastic body instead of the movable protrusion, the movable protrusion According to the movement of the position of the barrel of the optical component by changing the projection amount of the optical component, the elastic projection portion made of an elastic body is elastically deformed to hold the optical component, and thus the projection amount needs to be adjusted. The movable protrusion can be reduced, and the optical axis shift in the optical component can be easily adjusted.

  According to the invention described in claim 8, in an optical sensor comprising an optical component and an optical component holder for holding the optical component, any one of claims 1 to 7 as the optical component holder. Since the optical component holder described in the item is included, the shift of the optical axis in the optical component can be adjusted, and the direction of the optical axis can be made constant.

  According to the invention described in claim 9, an image carrier on which powder is adhered to a surface, and an optical sensor for detecting an adhesion amount of the powder adhered to the surface of the image carrier. Since at least the image forming apparatus has the optical sensor according to claim 8 as the optical sensor, the deviation of the optical axis in the optical component can be adjusted to make the direction of the optical axis constant. The adhesion amount of the powder can be detected accurately, and the image density can be adjusted accurately.

  Hereinafter, an embodiment of an optical component holder, an optical sensor, and an image forming apparatus according to the present invention will be described with reference to FIGS. 1 to 7 and FIGS. FIG. 1 is a front view showing an optical component holder according to an embodiment of the present invention. FIG. 2 is a cross-sectional perspective view taken along line XX of FIG. FIG. 3 is a diagram illustrating the positions of the first holding member and the second holding member when the optical component holder of FIG. 1 is viewed from the front. FIG. 4 is a cross-sectional perspective view showing a state in which the optical component holder of FIG. 1 holds an optical component with no optical axis deviation. FIG. 5 is a cross-sectional perspective view showing a state (before optical axis adjustment) in which the optical component holder of FIG. 1 holds an optical component with a deviation of the optical axis. FIG. 6 is a cross-sectional perspective view showing a state (after optical axis adjustment) in which the optical component holder in FIG. 1 holds an optical component with a deviation of the optical axis. FIG. 7 is a cross-sectional perspective view showing a state (after the optical axis adjustment) in which the optical component holder of FIG. 1 holds another optical component having an optical axis shift. FIG. 14 is a cross-sectional view showing an optical sensor according to an embodiment of the present invention. FIG. 15 is a cross-sectional view showing an image forming apparatus according to an embodiment of the present invention. 16 is a cross-sectional view showing a process cartridge provided in the image forming apparatus of FIG.

  First, an embodiment of the optical component holder 70 will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the optical component holder 70 includes a case 71, an accommodation hole 72, an optical path regulating member 73, a first holding member 74, and a second holding member 75.

  The case 71 is formed in a triangular prism shape using, for example, a light-transmitting synthetic resin. As long as the object of the present invention is not violated, the shape of the case 71 is arbitrary. The case 71 is provided with a housing hole 72 having a circular cross section that penetrates the case 71 in the axial direction.

  The accommodation hole 72 is provided so that its axis N overlaps with the axis of the case 71. The inner diameter of the accommodation hole 72 is made constant over the entire length of the accommodation hole 72 and is larger than the outer diameter of a body portion 85 of an optical component 80 to be described later such as a light emitting diode or a photodiode. The outer diameter of the flange portion 86 is smaller. As a result, when the optical component 80 is inserted into the accommodation hole 72, the flange portion 86 comes into contact with the end surface of the case 71, and the accommodation hole 72 is positioned in the axis N direction. An optical path regulating member 73 is provided at one end 72 b of the accommodation hole 72.

  The optical path regulating member 73 is provided with an opening 73 a whose center is overlapped with the axis N of the accommodation hole 72 and whose diameter is smaller than the inner diameter of the accommodation hole 72. The optical path regulating member 73 regulates the optical path W of the optical component 80 accommodated in the accommodation hole 72 and sets it as the optical path W1 that travels with the same diameter as the opening 73a. The optical path regulating member 73 prevents, for example, the light emitted from the light emitting diode from being unnecessarily spread or prevents unnecessary light from being received by the photodiode.

  The first holding member 74 is provided on the inner surface 72 a of the accommodation hole 72 and in the vicinity of the central portion in the axial direction of the accommodation hole 72. The first holding member 74 includes a fulcrum part 741 that protrudes in an annular shape over the circumferential direction of the inner surface 72 a of the accommodation hole 72. The fulcrum part 741 protrudes vertically from the inner surface 72 a of the accommodation hole 72. The fulcrum part 741 has a surface F1 surrounded by the inner edge 741a included in a transverse section of the body 85 of the optical component 80 (that is, a section perpendicular to the axis M direction of the body 85 of the optical component 80). Is formed. Thus, when the head 84 of the optical component 80 is brought into contact with the fulcrum 741, the optical component 80 is restricted from moving in the insertion direction (that is, in the direction of the axis N of the accommodation hole 72), and the head 84 is held by the inner edge 741a of the fulcrum part 741.

  The second holding member 75 is provided on the inner surface 72 a of the accommodation hole 72 and closer to the other end 72 c of the accommodation hole 72. That is, the second holding member 75 is provided away from the first holding member 74 along the axial direction of the accommodation hole 72. The second holding member 75 includes three movable protrusions 76 provided away from each other along the circumferential direction of the inner surface 72 a of the accommodation hole 72. The three movable protrusions 76 are desirably equally spaced from each other. Further, four or more movable protrusions 76 may be provided.

  The movable protrusion 76 includes a through hole 761 and a mover 762. The through hole 761 is provided through the inner surface 72 a of the accommodation hole 72 and the outer surface 71 a of the case 71 in a direction orthogonal to the axis N of the accommodation hole 72. The through hole 761 has a circular cross section, and the inner diameter of the through hole 761 is uniform over the entire length. A thread groove (not shown) is provided on the inner peripheral surface of the through hole 761. The mover 762 is a cylindrical member made of, for example, a light-transmitting synthetic resin or metal and having an outer diameter that is substantially the same as the inner diameter of the through hole 761. A screw thread (not shown) is provided on the outer peripheral surface of the mover 762 so as to be screwed into the thread groove of the through hole 761. The length of the mover 762 is shorter than the length of the through hole 761. One end 762 a of the mover 762 protrudes from the opening 761 a on the inner surface 72 a side of the accommodation hole 72 of the through hole 761. The other end 762b of the mover 762 is provided with a hexagonal groove (not shown) that is recessed in the axial direction. The mover 762 is also called a female screw.

  The through hole 761 and the mover 762 are screwed together. Then, for example, a hexagon wrench is inserted from the opening 761 b on the outer surface side of the case 71 of the through hole 761 and fitted into a hexagonal groove provided in the other end 762 b of the movable element 762, thereby moving the movable element 762. Is rotated about its axis, so that the mover 762 can be moved relative to the through-hole 761 in the axial direction. As a result, the one end 762a of the movable element 762 can be moved in the direction of projecting or immersing into the through hole 761 (that is, freely projecting and retracting), and the movable element 762 can be moved from the inner surface 72a of the accommodation hole 72. The amount of protrusion can be changed freely. That is, the amount of protrusion of the movable protrusion 76 from the inner surface of the accommodation hole 72 can be changed. The movable element 762 adjusts the amount of protrusion from the inner surface 72 a of the accommodation hole 72, so that one end 762 a abuts on the body 85 of the optical component 80 and holds the body 85 of the optical component 80. The body 85 of the optical component 80 can be moved in a direction orthogonal to the axial direction of the accommodation hole 72. In the present embodiment, the movable protrusion 76 has a screw structure in which the through-hole 761 and the movable element 762 are screwed together. However, the through-hole is not provided with such a screw structure. The inner diameter of 761 and the outer diameter of the movable element 762 are respectively formed in a cylindrical hole shape and a cylindrical shape, and are held by the frictional force between the inner peripheral surface of the through hole 761 and the outer peripheral surface of the movable element 762. Then, by relatively pushing or pulling the mover 762 along the axial direction, the one end portion 762a of the mover 762 may be protruded (projected or immersed) into the through hole 761. .

  As shown in FIG. 4, the optical component holder 70 accommodates the optical component 80 in the accommodation hole 72 and holds the optical component 80 by the first holding member 74 and the second holding member 75. At this time, the amount of protrusion from the inner surface 72 a of the accommodation hole 72 of the three movable protrusions 76 (that is, the movable element 762) of the second holding member 75 is adjusted, and the optical axis L of the optical component 80 is adjusted to the By holding the optical component 80 so as to coincide with the axis N, the direction of the optical axis L of the optical component 80 can be made constant.

  The optical component 80 is a well-known electronic component such as a bullet-type light emitting diode, a photodiode, or a phototransistor. The optical component 80 includes an optical element 81 such as a light-emitting element (light-emitting diode) that emits light when a current is passed, or a light-receiving element (photodiode or phototransistor) that generates a current or a voltage according to the amount of received light. A pair of lead wires 82 connected to each other, a hemispherical head portion 84, a cylindrical body portion 85 connected to the head portion 84, and a flange portion 86 provided at an end portion of the body portion 85. And a sealing member 83 in which the optical element 81 is sealed. It is desirable that the optical axis L of the optical component 80 coincides with the axis M of the body 85 of the sealing member 83 of the optical component 80 (that is, the body 85 of the optical component 80). However, there are cases where the optical axis L and the axis M of the body 85 are shifted due to manufacturing errors of the optical component 80.

  Next, a procedure for holding the optical component 80 using the above-described optical component holder 70 will be described with reference to FIGS.

  First, the optical component 80 is inserted into the accommodation hole 72 from the other end 72c of the accommodation hole 72 with the head portion 84 first, and the head portion 84 of the optical component 80 is brought into contact with the fulcrum portion 741. Thereby, the optical component 80 is restricted from moving in the insertion direction (that is, the axial direction of the accommodation hole 72), and the head portion 84 of the optical component 80 is held in the inner edge 741a of the fulcrum portion 741. Next, in each of the three movable protrusions 76, the mover 762 of the movable protrusion 76 is rotated around its axis using a hexagon wrench, and one end 762 a of the mover 762 is moved to the body of the optical component 80. It abuts on the part 85. In this way, the body 85 of the optical component 80 is sandwiched and held by the three movable protrusions 76.

  At this time, as shown in FIG. 4, when the optical axis L of the optical component 80 and the axis M of the body 85 coincide with each other, the accommodation hole 72 of the movable element 762 in each of the three movable protrusions 76. The amount of protrusion from the inner surface 72a is adjusted to be the same. Accordingly, the axis M of the body 85 of the optical component 80 is the same as the axis N of the accommodation hole 72, that is, the optical axis L is the same as the axis N of the accommodation hole 72.

  Further, as shown in FIG. 5, when the optical axis L of the optical component 80 and the axis M of the body 85 are misaligned, the axis M of the body 85 of the optical component 80 and the axis N of the receiving hole are the same. As a result, the optical axis L of the optical component 80 is shifted from the axis N of the receiving hole. Therefore, in each of the three movable protrusions 76, the amount of protrusion from the inner surface 72a of the accommodation hole 72 of the mover 762 is adjusted as appropriate, and the body 85 of the optical component 80 is perpendicular to the axis N of the accommodation hole 72. As shown in FIG. 6, the optical axis L of the optical component 80 and the axis N of the accommodation hole 72 are made the same. Further, as shown in FIG. 7, even in the case where the optical axis L of the optical component 80 and the axis M of the body 85 are shifted in the opposite direction to FIG. The amount of protrusion from the inner surface 72a of 72 is adjusted as appropriate so that the optical axis L of the optical component 80 and the axis N of the accommodation hole 72 are the same.

  Finally, an adhesive (not shown) as a fixing member is poured into the through holes 761 of each movable protrusion 76 to fix the movable element 762 to the through holes 761. In this way, the shift of the optical axis L of the optical component 80 is adjusted by changing the amount of protrusion of the movable protrusion 76 (that is, the movable element 762) from the inner surface 72a of the accommodation hole 72, so The optical axis L and the axis N of the receiving hole 72 can be made coincident, and the direction of the optical axis L of the optical component 80 can be made constant.

  As described above, according to the present invention, the first holding member 74 having the fulcrum part 741 projecting annularly over the circumferential direction of the inner surface 72a of the accommodation hole 72 is provided, and the fulcrum part 741 has its inner edge. Since the surface F1 surrounded by 741a is formed so as to be included in the transverse section of the body 85 of the optical component 80 (that is, the section orthogonal to the axial direction of the body 85), the optical component 80 is accommodated. When inserted into the hole 72, the head portion 84 of the optical component 80 abuts against the fulcrum portion 741 to restrict movement in the insertion direction, and the head portion 84 of the optical component 80 fits into the inner edge 741a of the fulcrum portion 741. Held. In addition, the second holding member 75 having three movable protrusions 76 that are evenly spaced apart from each other along the circumferential direction of the inner surface 72 a of the receiving hole 72 is a first holding member along the axial direction of the receiving hole 72. Accordingly, the body 85 of the optical component 80 is held by the plurality of movable protrusions 76. Since the plurality of movable protrusions 76 can freely change the amount of protrusion from the inner surface 72a of the accommodation hole 72, by changing the amount of protrusion of the movable protrusion 76, the fulcrum part 741 is used as a fulcrum. The position of the body 85 of the component 80 can be moved with respect to the direction orthogonal to the axial direction of the accommodation hole 72, so that the optical axis L of the optical component 80 can be moved. The direction of the optical axis L can be made constant by adjusting the deviation of the axis L to coincide with the axis N of the receiving hole 72.

  Further, the movable protrusion 76 protrudes into a through hole 761 provided through the inner surface 72a of the accommodation hole 72 and the outer surface 71a of the case 71, and an opening 761a on the inner surface 72a side of the accommodation hole 72 in the through hole 761. And a movable element 762 that can be freely moved. Therefore, by adjusting the position of the movable element 762 from the outside of the case 71, the amount of protrusion from the inner surface 72a of the accommodation hole 72 can be changed. The deviation of the optical axis L in the component 80 can be easily adjusted. Moreover, since it is a simple structure, the optical component holder 70 which can adjust the shift | offset | difference of the optical axis L in the optical component 80 can be provided at low cost.

  Further, since the length of the movable element 762 is shorter than the length of the through hole 761, when the movable element 762 protrudes from the inner surface 72 a of the accommodation hole 72, the movable element 762 protrudes from the outer surface 71 a of the case 71. For example, it is possible to prevent the position of the optical component 80 from changing due to contact with the movable element 762 during assembly or the like, and to prevent the optical axis L from being shifted in the optical component 80.

  In addition, a thread groove is provided on the inner peripheral surface of the through hole 761, and a screw thread that is screwed into a screw groove provided on the inner surface of the through hole 761 is provided on the outer peripheral surface of the movable element 762. Therefore, the movable protrusion 76 is constituted by a screw structure, and therefore, the shift of the optical axis L in the optical component 80 can be adjusted more easily.

  Further, after the optical component is held by the first holding member 74 and the second holding member 75, an adhesive is provided as a fixing member that fixes the movable element 762 to the through hole 761. After the optical axis adjustment, the movable element 762 can be fixed to the through-hole 761 with an adhesive, so that the position of the optical component 80 can be prevented from changing, and in the optical component 80 after the optical axis adjustment. Deviation of the optical axis can be prevented.

  In the above-described embodiment, the first holding member 74 includes the fulcrum part 741 that protrudes in an annular shape over the circumferential direction of the inner surface 72a of the accommodation hole 72. The one holding member may include three or more fulcrum portions that protrude away from each other along the circumferential direction of the inner surface 72 a of the accommodation hole 72. An optical component holder 70A having such a configuration is shown in FIGS.

  As shown in FIGS. 8 and 9, the optical component holder 70 </ b> A includes a first holding member 74 </ b> A including a plurality of fulcrum portions 77 instead of the first holding member 74 of the above-described embodiment. 8 and 9, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The first holding member 74 </ b> A is provided on the inner surface 72 a of the accommodation hole 72 and in the vicinity of the central portion in the axial direction of the accommodation hole 72. The first holding member 74 </ b> A includes three prismatic fulcrum portions 77 that protrude away from each other along the circumferential direction of the inner surface 72 a of the accommodation hole 72. It is desirable that these three fulcrum portions 77 are equally spaced from each other. Each of the three fulcrum portions 77 is arranged so that the position along the circumferential direction of the accommodation hole 72 is in the middle of each of the three movable protrusions 76 as shown in FIG. Further, four or more fulcrum portions 77 may be provided. Each of the three fulcrum portions 77 protrudes vertically from the inner surface 72 a of the accommodation hole 72. The three fulcrum portions 77 have a surface F2 surrounded by a circle at their tips 77a in a transverse cross section of the body 85 of the optical component 80 (that is, a cross section perpendicular to the axial direction of the body 85 of the optical component 80). It is formed to be included. Thereby, when the head 84 of the optical component 80 is brought into contact with the three fulcrum portions 77, the optical component 80 is restricted from moving in the insertion direction (that is, the axial direction of the receiving hole 72), and the head The portion 84 is held between the tips 77 a of the three fulcrum portions 77.

  As described above, the optical component holder 70A includes the three fulcrum portions 77 in the shape of prisms that are protruded away from each other along the circumferential direction of the inner surface 72a of the accommodation hole 72 in the first holding member 74A. In addition to the effects of the embodiment described above, the contact area between the head portion 84 of the optical component 80 and each fulcrum portion 77 can be reduced, so that the position of the body 85 of the optical component 80 can be moved smoothly, and the optical component The deviation of 80 optical axes can be adjusted with high accuracy.

  In the above-described embodiment, the second holding member 75 includes the three movable protrusions 76 that are provided apart from each other along the circumferential direction of the inner surface 72 a of the accommodation hole 72. According to the invention, at least one protrusion of the plurality of protrusions included in the second holding member may be an elastic protrusion formed of an elastic body instead of the operating protrusion. The optical component holder 70B having such a configuration is shown in FIGS.

  As shown in FIGS. 10 and 11, the optical component holder 70 </ b> B includes a second holding member 75 </ b> A including a movable protrusion and an elastic protrusion instead of the second holding member 75 of the above-described embodiment. 10 and 11, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The second holding member 75 </ b> A is provided on the inner surface 72 a of the accommodation hole 72 and closer to the other end portion 72 c of the accommodation hole 72. That is, the second holding member 75 </ b> A is provided away from the first holding member 74 along the axial direction of the accommodation hole 72. The second holding member 75 </ b> A includes one movable projecting portion 76 and two elastic projecting portions 78 provided apart from each other along the circumferential direction of the inner surface 72 a of the accommodation hole 72. It is desirable that each of these three protrusions be equally spaced from each other. Further, if the total number of the movable protrusions 76 and the elastic protrusions 78 is three or more and at least one movable protrusion 76 is provided, the number of the respective protrusions is arbitrary.

  The elastic projecting portion 78 is made of, for example, an elastic body such as columnar rubber, a coil spring, or a leaf spring, and is a well-known member that biases in a direction to restore against compression. One end of the elastic protrusion 78 is fixed to the inner surface 72 a of the accommodation hole 72. Further, the elastic projection 78 has its other end abutted against the body 85 of the optical component 80 housed in the housing hole 72 and urges the body 85 in a direction perpendicular to the axis N of the housing hole 72. The length is adjusted to do so. When the position of the body 85 of the optical component 80 is moved by the movable protrusion 76 and the elastic protrusion 78 is compressed, the elastic protrusion 78 urges the body 85 of the optical component 80 in the direction of pushing back.

  As described above, the optical component holder 70B includes the second holding member 75A having one movable protrusion 76 and two elastic protrusions 78 provided apart from each other along the circumferential direction of the inner surface 72a of the accommodation hole 72. In addition to the effects in the above-described embodiment, the elastic protrusion 78 is elastically deformed in accordance with the movement of the body 85 of the optical component 80 by changing the protrusion amount of the movable protrusion 76. Therefore, it is possible to reduce the number of movable protrusions 76 that need to be adjusted, and to easily adjust the deviation of the optical axis in the optical component 80.

  In the embodiment described above, both the first holding member 74A and the second holding member 75A may be provided instead of the first holding member 74 and the second holding member 75. The optical component holder 70C having such a configuration is shown in FIGS. In FIGS. 12 and 13, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As described above, since the optical component holder 70C includes both the first holding member 74A and the second holding member 75A, in addition to the effects in the above-described embodiment, the head 84 and each fulcrum of the optical component 80 are provided. Since the contact area with the portion 77 can be reduced, the position of the body portion 85 of the optical component 80 can be moved smoothly, and the optical axis shift of the optical component 80 can be adjusted with high accuracy. Further, in accordance with the movement of the position of the body 85 of the optical component 80 by changing the amount of protrusion of the movable protrusion 76, the elastic protrusion 78 is elastically deformed to hold the optical component 80, and therefore adjustment is necessary. Thus, the movable protrusion 76 can be reduced, and the optical axis shift in the optical component 80 can be easily adjusted.

  Next, an embodiment of an optical sensor will be described with reference to FIG.

  The optical sensor 99 includes a light emitting diode 80A as an optical component, photodiodes 80B and 80C as optical components, the three optical component holders 70 that hold the LEDs 80A and the photodiodes 80B and 80C, and a substrate 95. I have.

  The optical sensor 99 is disposed relative to a later-described transport belt 29 by a support member (not shown) and the like, and detects the toner adhesion amount of the density detection toner patch 90 formed on the surface 29a of the transport belt 29. . The density detection toner patch 90 is formed in a gradation pattern in which the density gradually increases from downstream to upstream in the movement direction of the conveyor belt 29 (that is, the toner adhesion amount increases). Further, depending on the configuration of the image forming apparatus in which the optical sensor 99 is incorporated, the optical sensor 99 is disposed relative to a photosensitive member or an intermediate transfer member as an image carrier, and is formed on the surface of these image carriers. The toner adhesion amount of the toner patch 90 may be detected.

  The light emitting diode 80A (hereinafter referred to as the LED 80A) is a well-known electronic component that emits light when an electric current flows. The LED 80A includes, for example, an optical element 81 that is a light-emitting element that emits light when an electric current is passed, a pair of lead wires 82 connected to the optical element 81, a hemispherical head 84, and the like, as shown in FIG. A transparent or semi-transparent composite having a cylindrical body 85 connected to the head 84 and a flange 86 provided at the end of the body 85 and having an optical element 81 sealed therein. And a sealing member 83 made of resin. The LED 80A is formed in a so-called bullet shape. For the optical element 81 of the LED 80A, for example, a GaAs element having a peak emission wavelength of 950 nm is used.

  The LED 80 </ b> A is held by the above-described optical component holder 70 (indicated by reference numeral 70-1) and mounted on the substrate 95. Further, the optical axis L1 of the LED 80A is adjusted by the optical component holder 70-1 so that the direction of the irradiation light of the LED 80A becomes a desired direction.

  The photodiodes 80B and 80C are well-known electronic components that generate a voltage according to the amount of received light. Each photodiode includes, for example, an optical element 81 that is a light-receiving element that generates a current or a current according to the amount of received light, a pair of lead wires 82 connected to the optical element 81, and the LED 80A as shown in FIG. And the same sealing member 83. The photodiodes 80B and 80C are formed in a so-called bullet shape. As the optical element 81 of each photodiode, for example, a Si element having a peak spectral sensitivity wavelength of 800 nm is used. In the present embodiment, a photodiode is used. However, the present invention is not limited to this, and a phototransistor, a photodarlington, or the like that generates a voltage or current according to the amount of received light and is formed in a shell shape. Can be used.

  The photodiode 80 </ b> B receives specularly reflected light obtained by specularly reflecting the irradiation light of the LED 80 </ b> A by the density detection toner patch 90 formed on the surface 29 a of the transport belt 29. That is, the photodiode 80B functions as a regular reflection light receiving element. The photodiode 80 </ b> C receives diffusely reflected light obtained by diffusing and reflecting the irradiation light of the LED 80 </ b> A by the density detection toner patch 90 formed on the surface 29 a of the transport belt 29. That is, the photodiode 80C functions as a diffuse reflection light receiving element.

  The photodiode 80B is held by the above-described optical component holder 70 (indicated by reference numeral 70-2) and mounted on the substrate 95. Further, the optical axis L2 of the photodiode 80B is adjusted to be in a predetermined direction by the optical component holder 70-2 so that the photodiode 80B receives the regular reflection light. The photodiode 80C is held by the above-described optical component holder 70 (indicated by reference numeral 70-3) and mounted on the substrate 95. Further, the optical axis L3 of the photodiode 80C is adjusted to a predetermined direction by the optical component holder 70-3 so that the photodiode 80C receives the diffuse reflected light.

  The substrate 95 is a well-known printed wiring board in which thin-film metal circuit wiring is provided on the surface of a flat plate made of synthetic resin. The substrate 95 is arranged on one surface such that one outer surface 71a of the case 71 of each optical component holder 70 described above is densely stacked, and a pair of leads of the LED 80A and the photodiodes 80B and 80C. The wire is soldered. These optical components are electrically connected to a control unit (not shown) via the substrate 95, receive light from a control signal from the control unit, and irradiate the control unit with a voltage corresponding to the amount of received light. Output.

  As described above, according to the present invention, the optical sensor 99 includes the optical component holder 70 described above as the optical component holder that holds the LED 80A and the photodiodes 80B and 80C. And the direction of the optical axis can be made constant.

  Next, an embodiment of the image forming apparatus will be described with reference to FIGS. 15 and 16.

  The image forming apparatus 1 prints an image of each color of yellow (Y), magenta (M), cyan (C), and black (K), that is, a color image, on a recording sheet 7 as a single transfer material (shown in FIG. 7). ) To form. The units corresponding to the colors of yellow, magenta, cyan, and black are indicated by adding Y, M, C, and K at the end of the reference numerals.

  As shown in FIG. 15, the image forming apparatus 1 includes an apparatus main body 2, a paper feeding unit 3, a registration roller pair 10, a transfer unit 4, a fixing unit 5, and a plurality of laser writing units 22Y, 22M, and 22C. , 22K, a plurality of process cartridges 6Y, 6M, 6C, 6K, and the optical sensor 99 described above.

  The apparatus main body 2 is formed in a box shape, for example, and is installed on a floor or the like. The apparatus main body 2 includes a paper feeding unit 3, a registration roller pair 10, a transfer unit 4, a fixing unit 5, a plurality of laser writing units 22Y, 22M, 22C, and 22K, and a plurality of process cartridges 6Y, 6M, and 6C. , 6K and the optical sensor 99 are accommodated.

  A plurality of paper feed units 3 are provided in the lower part of the apparatus main body 2. The paper feeding unit 3 includes a paper feeding cassette 23 that can accommodate the recording paper 7 described above in a stacked manner and can be taken in and out of the apparatus main body 2 and a paper feeding roller 24. The paper feed roller 24 is pressed against the uppermost recording paper 7 in the paper feed cassette 23. The paper feed roller 24 is used to transfer the above-mentioned uppermost recording paper 7 between a transport belt 29 described later of the transfer unit 4 and a photosensitive drum 8 of the developing device 13 described later of the process cartridges 6Y, 6M, 6C, and 6K. Send it in between.

  The registration roller pair 10 is provided in the conveyance path of the recording paper 7 conveyed from the paper supply unit 3 to the transfer unit 4, and includes a pair of rollers 10a and 10b. The registration roller pair 10 includes the transfer unit 4 and the process cartridges 6Y, 6M, 6C, and 6K at a timing at which the recording sheet 7 is sandwiched between the pair of rollers 10a and 10b and the sandwiched recording sheet 7 can be superimposed on the toner image. Send out in between.

  The transfer unit 4 is provided above the paper feed unit 3. The transfer unit 4 includes a drive roller 27, a driven roller 28, a conveyor belt 29, and transfer rollers 30Y, 30M, 30C, and 30K. The driving roller 27 is disposed on the downstream side in the conveyance direction of the recording paper 7 and is rotationally driven by a motor as a driving source. The driven roller 28 is rotatably supported by the apparatus main body 2 and is disposed on the upstream side in the conveyance direction of the recording paper 7. The conveyor belt 29 is formed in an endless annular shape and is stretched over both the driving roller 27 and the driven roller 28 described above. The conveying belt 29 circulates (endlessly travels) counterclockwise around the driving roller 27 and the driven roller 28 described above as the driving roller 27 is rotationally driven.

  The optical sensor 99 is disposed in the vicinity of the driving roller 27 of the conveyor belt 29 and opposed to the surface 29 a of the conveyor belt 29. The optical sensor 99 detects the toner adhesion amount of the density detection toner patch 90 formed on the surface 29 a of the transport belt 29 and outputs a voltage corresponding to the adhesion amount. A voltage corresponding to the toner adhesion amount output from the optical sensor 99 is sent to a control unit (not shown). This control unit is constituted by a microcomputer or the like.

  The transfer rollers 30Y, 30M, 30C, and 30K sandwich the conveyance belt 29 and the recording paper 7 on the conveyance belt 29 between the photosensitive drums 8 of the process cartridges 6Y, 6M, 6C, and 6K, respectively. In the transfer unit 4, the transfer rollers 30Y, 30M, 30C, and 30K press the recording paper 7 fed from the paper feed unit 3 against the outer surface of the photosensitive drum 8 of each process cartridge 6Y, 6M, 6C, and 6K. The toner image on the photosensitive drum 8 is transferred to the recording paper 7. The transfer unit 4 sends the recording paper 7 onto which the toner image has been transferred toward the fixing unit 5.

  The fixing unit 5 is provided downstream of the transfer unit 4 in the conveyance direction of the recording paper 7 and includes a pair of rollers 5 a and 5 b that sandwich the recording paper 7 therebetween. The fixing unit 5 presses and heats the recording paper 7 sent out from the transfer unit 4 between the pair of rollers 5a and 5b, whereby the toner image transferred from the photosensitive drum 8 onto the recording paper 7 is recorded on the recording paper 7. Fix to paper 7.

  The laser writing units 22Y, 22M, 22C, and 22K are attached to the upper part of the apparatus main body 2, respectively. The laser writing units 22Y, 22M, 22C, and 22K correspond to one process cartridge 6Y, 6M, 6C, and 6K, respectively. The laser writing units 22Y, 22M, 22C, and 22K irradiate laser beams onto the outer surface of the photosensitive drum 8 that is uniformly charged by a later-described charging roller 9 of the process cartridges 6Y, 6M, 6C, and 6K. An electrostatic latent image is formed.

  The process cartridges 6Y, 6M, 6C, and 6K are provided between the transfer unit 4 and the laser writing units 22Y, 22M, 22C, and 22K, respectively. The process cartridges 6Y, 6M, 6C, and 6K are detachable from the apparatus main body 2. The process cartridges 6Y, 6M, 6C, and 6K are arranged in parallel along the conveyance direction of the recording paper 7.

  As shown in FIG. 16, the process cartridges 6Y, 6M, 6C, and 6K include a cartridge case 11, a charging roller 9 as a charging device, a photosensitive drum 8 as an image carrier (also referred to as a photosensitive member), and a cleaning. A cleaning blade 12 as an apparatus, a developing device 13, and a developer supply device 35 are provided. For this reason, the image forming apparatus 1 includes at least a charging roller 9, a photosensitive drum 8, a cleaning blade 12, a developing device 13, and a developer supply device 35.

  The cartridge case 11 is detachable from the apparatus main body 2 and accommodates a charging roller 9, a photosensitive drum 8, a cleaning blade 12, a developing device 13, and a developer supply device 35. The charging roller 9 uniformly charges the outer surface of the photosensitive drum 8.

  The photosensitive drum 8 is disposed with a gap from a later-described developing roller 15 of the developing device 13. The photosensitive drum 8 is formed in a columnar shape or a cylindrical shape that is rotatable about an axis. The photoconductor drum 8 corresponds after the outer surface thereof is uniformly charged (for example, −500 V to −700 V) by a charging bias obtained by superimposing the AC voltage and the DC voltage applied to the charging roller 9. Laser light is irradiated by the laser writing units 22Y, 22M, 22C, and 22K, and an electrostatic latent image is formed on the outer surface thereof. The photoreceptor drum 8 is developed on the electrostatic latent image formed on the outer surface and attracted with the toner 36, and the toner image thus obtained is recorded on the recording paper 7 positioned between the conveyance belt 29. Transcript. The cleaning blade 12 removes the toner 36 remaining on the outer surface of the photosensitive drum 8 after transferring the toner image to the recording paper 7.

  As shown in FIG. 16, the developing device 13 includes at least a developer supply unit 14, a case 25, a regulating blade 16 as a regulating member, and a developing roller 15 as a developer carrier.

  The developer supply unit 14 includes a storage tank 17 and a pair of stirring screws 18 as stirring members. The storage tank 17 is formed in a box shape whose length is substantially equal to that of the photosensitive drum 8. A partition wall 19 extending along the longitudinal direction of the storage tank 17 is provided in the storage tank 17. The partition wall 19 partitions the storage tank 17 into a first space 20 and a second space 21. Further, both ends of the first space 20 and the second space 21 communicate with each other.

  The storage tank 17 stores the developer 26 in both the first space 20 and the second space 21. The developer 26 includes toner 36 as powder and a magnetic carrier. A supply hole 37 is opened at one end of the first space 20 on the side away from the developing roller 15 in the first space 20 and the second space 21. The toner 36 is appropriately supplied through a supply hole 37 by a developer supply device 35 described later.

  The toner 36 is spherical fine particles manufactured by an emulsion polymerization method or a suspension polymerization method. The toner 36 may be obtained by pulverizing a lump composed of a synthetic resin in which various dyes or pigments are mixed and dispersed. The average particle size of the toner 36 is 3 μm or more and 7 μm or less. The toner 36 may be formed by pulverization or the like.

  The magnetic carrier is accommodated in both the first space 20 and the second space 21. The average particle size of the magnetic carrier is 20 μm or more and 35 μm or less. The magnetic carrier includes a spherical core material made of ferrite as a magnetic material, a resin component obtained by crosslinking a thermoplastic resin such as acrylic and a melamine resin, and a charge control agent, and the outer surface of the core material And a spherical alumina particle dispersed in the resin coat film.

  The stirring screw 18 is accommodated in each of the first space 20 and the second space 21. The longitudinal direction of the stirring screw 18 is parallel to the longitudinal directions of the storage tank 17, the developing roller 15, and the photosensitive drum 8. The agitating screw 18 is provided so as to be rotatable around an axis, and rotates around the axis to agitate the toner 36 and the magnetic carrier and convey the developer 26 along the axis.

  In the illustrated example, the agitation screw 18 in the first space 20 conveys the developer 26 from one end to the other end. The agitating screw 18 in the second space 21 conveys the developer 26 from the other end portion to one end portion.

  According to the configuration described above, the developer supply unit 14 conveys the toner 36 supplied to one end of the first space 20 to the other end while stirring with the magnetic carrier, and the second space is supplied from the other end to the second space. 21 to the other end. The developer supply unit 14 agitates the toner 36 and the magnetic carrier in the second space 21 and supplies them to the outer peripheral surface of the developing roller 15 while transporting the toner 36 and the magnetic carrier in the axial direction.

  The case 25 is formed in a box shape, is attached to the storage tank 17 of the developer supply unit 14 described above, and covers the developing roller 15 and the like together with the storage tank 17. In addition, an opening 25 a is provided in a portion of the case 25 that faces the photosensitive drum 8.

  The regulating blade 16 is formed in a flat plate shape, and is provided between the end of the storage tank 17 near the photosensitive drum 8, that is, between the storage tank 17 and the photosensitive drum 8 in the rotation direction of the developing sleeve 32 described later. . The regulation blade 16 is attached to the storage tank 17 in a state of protruding from the storage tank 17 toward the developing roller 15. The regulating blade 16 is attached to the case 25 described above with a space from the outer surface of the developing sleeve 32. The regulating blade 16 scrapes off the developer 26 on the outer surface of the developing sleeve 32 exceeding the desired thickness into the storage tank 17, and the developer 26 on the outer surface of the developing sleeve 32 conveyed to the developing region 31. To the desired thickness.

  The developing roller 15 is formed in a cylindrical shape, and is provided between the second space 21 and the photosensitive drum 8 and in the vicinity of the opening 25a described above. The developing roller 15 is parallel to both the photosensitive drum 8 and the storage tank 17. The developing roller 15 is disposed at a distance from the photosensitive drum 8. The gap between the developing roller 15 and the photosensitive drum 8 forms a developing region 31 in which the toner 36 of the developer 26 is attracted to the photosensitive drum 8 and the electrostatic latent image is developed to obtain a toner image. . In the developing area 31, the developing roller 15 and the photosensitive drum 8 face each other.

  As shown in FIG. 16, the developing roller 15 includes a cylindrical cored bar 34, a cylindrical magnet roller (also referred to as a magnet body) 33, and the above-described developing sleeve 32 as a nonmagnetic cylindrical body. . The core metal 34 is arranged in parallel with the longitudinal direction of the photosensitive drum 8 in the longitudinal direction, and is fixed to the case 25 without rotating.

  The magnet roller 33 is made of a magnetic material, is formed in a cylindrical shape, and is provided with a plurality of fixed magnetic poles. The magnet roller 33 is fixed to the outer periphery of the cored bar 34 without rotating around the axis.

  The fixed magnetic pole is a long and rod-like magnet, and is attached to the roller body 33 a of the magnet roller 33. The fixed magnetic pole extends along the roller body 33 a of the magnet roller 33, that is, along the longitudinal direction of the developing roller 15, and is provided over the entire length of the roller body 33 a of the magnet roller 33. The magnet roller 33 configured as described above is accommodated (enclosed) in the developing sleeve 32.

  One fixed magnetic pole generates a magnetic force on the outer peripheral surface of the developing sleeve 32, that is, the developing roller 15, relative to the agitating screw 18 described above, and causes the developer 26 in the second space 21 of the storage tank 17 to move to the developing sleeve. It adsorbs to the outer peripheral surface of 32.

  The other fixed magnetic pole generates a magnetic force on the outer peripheral surface of the developing sleeve 32, that is, the developing roller 15, relative to the above-described photosensitive drum 8, and a magnetic field is generated between the developing sleeve 32 and the photosensitive drum 8. Form. The fixed magnetic pole forms a magnetic brush by the magnetic field, so that the toner 36 of the developer 26 adsorbed on the outer peripheral surface of the developing sleeve 32 is delivered to the photosensitive drum 8.

  In addition to the two fixed magnetic poles described above, the magnet roller 33 transports the developer 26 before development from the storage tank 17 of the developer supply unit 14 to the development region 31 and develops the developed developer 26. A fixed magnetic pole is provided for transporting from the region 31 to the storage tank 17.

  When the developer 26 adsorbs the developer 26 to the outer peripheral surface of the developing sleeve 32, the fixed magnetic pole, that is, the magnet roller 33 described above, superimposes a plurality of magnetic carriers of the developer 26 along the lines of magnetic force generated by the fixed magnetic pole. Stand on the surface. In this way, a state in which a plurality of magnetic carriers are erected on the outer surface of the developing sleeve 32 along the lines of magnetic force is called a magnetic carrier rising on the outer surface of the developing sleeve 32. Then, the toner 36 described above is adsorbed to the magnetic carrier that has grown up. That is, the developing sleeve 32 attracts the developer 26 to the outer surface by the magnetic force of the magnet roller 33.

  The developing sleeve 32 is formed in a cylindrical shape as shown in FIG. The developing sleeve 32 encloses (accommodates) the magnet roller 33 and is provided to be rotatable around the axis. The developing sleeve 32 is rotated so that the inner peripheral surface thereof is sequentially opposed to the fixed magnetic pole. The developing sleeve 32 is made of a nonmagnetic material such as an aluminum alloy or stainless steel (SUS). A developing bias (for example, −300 V to −500 V) in which an AC voltage and a DC voltage are superimposed is applied to the developing sleeve 32 by a voltage applying device (not shown).

  In the present embodiment, the developing sleeve 32 has a large number of random elliptical recesses on its outer peripheral surface. Of course, such a random oval-shaped recess is formed as a recess from the outer peripheral surface of the developing sleeve 32, and the longitudinal direction is along the axial direction of the developing sleeve 32 and the longitudinal direction is along the circumferential direction of the developing sleeve 32. Is provided. The number of dents along the axial direction of the developing sleeve 32 in the longitudinal direction is greater than the number of dents along the circumferential direction of the developing sleeve 32 in the longitudinal direction. Further, the length (major axis) in the longitudinal direction of the dent is 0.05 mm or more and 0.3 mm or less, and the width (end diameter) in the width direction is 0.02 mm or more and 0.1 mm or less. It has become.

  The dents are made of a medium (for example, austenitic stainless steel or martensitic stainless steel) made of a relatively large cut wire (a metal wire cut into a short length). It is made of a material, and the outer diameter is 0.5 mm or more and 1.2 mm or less. When the overall length is L and the outer diameter is D, L / D is 4 or more and 10 or less. It is formed in the rotating magnetic field, revolves around the element tube while rotating the medium by the rotating magnetic field, and collides with the outer peripheral surface of the element tube.

  In this way, the recess is formed by causing the medium to collide with the base tube as in the conventional blasting method. As described above, when the developing sleeve 32 has many random oval-shaped dents on the outer peripheral surface thereof, the developing sleeve 32 has irregularities with rough pitch on the surface. Thick ears rooted at each dent are formed, and the dents are also less likely to be worn. Therefore, a stable and good image with no image unevenness can be obtained over a long period of time.

  The developing device 13 configured as described above sufficiently agitates the toner 36 and the magnetic carrier by the developer supply unit 14, and adsorbs the agitated developer 26 to the outer surface of the developing sleeve 32. In the developing device 13, the developing sleeve 32 rotates, and the developer 26 adsorbed on the developing sleeve 32 is conveyed toward the developing region 31.

  Then, the developing device 13 scrapes off the developer 26 exceeding the desired thickness with the regulating blade 16, and causes the developer 26 having the desired thickness to be adsorbed to the photosensitive drum 8. In this way, the developing device 13 carries the developer 26 on the developing roller 15 and transports it to the developing area 31 to develop the electrostatic latent image on the photosensitive drum 8 to form a toner image.

  Then, the developing device 13 conveys the developed developer 26 to the storage tank 17 and separates it into the storage tank 17. Further, the developed developer 26 accommodated in the accommodating tank 17 is again sufficiently agitated with the other developer 26 in the second space 21, and the electrostatic latent image of the photosensitive drum 8 is Used for development.

  The developer supply device 35 is attached above the developer supply unit 14 of the developing device 13. The developer supply device 35 includes a toner container 40 and a transport tank 41 that are connected to each other. The developer supply device 35 loosens the toner 36 stored in the toner container 40 in the transport tank 41 according to the amount (concentration) of the toner 36 in the developer supply unit 14, and then develops the toner 36. It is supplied to the second space 21 of the agent supply unit 14.

  The image forming apparatus 1 configured as described above forms an image on the recording paper 7 as described below.

  First, the image forming apparatus 1 rotates the photosensitive drum 8 and uniformly charges (−500 V to −700 V) the outer surface of the photosensitive drum 8 with the charging roller 9 to which a charging bias is applied. When a laser beam corresponding to the image formed on the outer surface of the photosensitive drum 8 is irradiated, the potential of the portion irradiated with the laser beam becomes about −50 V, and an electrostatic latent image developed with toner is formed. It is formed. When the electrostatic latent image is positioned in the development region 31, the toner 36 of the developer 26 adsorbed on the outer surface of the development sleeve 32 of the development device 13 is developed with a development bias (−300V to −300V) applied to the development sleeve 32. 500 V), the electrostatic latent image is attracted to the electrostatic latent image which is a low potential portion of the photosensitive drum 8 to develop the electrostatic latent image, and a toner image is formed on the outer surface of the photosensitive drum 8.

  In the image forming apparatus 1, the recording paper 7 conveyed by the paper supply roller 24 of the paper supply unit 3 is transferred to the photosensitive drums 8Y, 8M, 8C, and 8K of the process cartridges 6Y, 6M, 6C, and 6K. The toner images formed on the outer surfaces of the photosensitive drums 8Y, 8M, 8C, and 8K, which are positioned between the transfer belt 4 and the transfer belt 4, are sequentially transferred onto the recording paper 7. The image forming apparatus 1 fixes the toner image on the recording paper 7 with the fixing unit 5. Thus, the image forming apparatus 1 forms a color image on the recording paper 7.

  Further, in the image forming apparatus 1 described above, apart from the image forming operation as described above, a process control operation (hereinafter referred to as a process control operation) for optimizing the image density of each color when the power is turned on or after a predetermined number of sheets have passed. ) Is executed. In this process control operation, density detection toner patches 90 (hereinafter referred to as reference patterns) are formed on the surface 29a of the conveyor belt 29 so as not to overlap each other for each color (Y, M, C, K). The reference pattern formed on the surface 29a of the transport belt 29 is a pattern that becomes continuous gradation by sequentially switching the charging bias and the developing bias. That is, in this embodiment, a line-shaped reference pattern in which the toner adhesion amount changes in gradation is created along the surface movement direction of the conveyor belt 29.

  In the image forming apparatus 1, the optical sensor 99 detects the toner adhesion amount of the reference pattern whose toner density changes in gradation. The photodiode 80B and the photodiode 80C of the optical sensor 99 output a voltage corresponding to the toner adhesion amount, and this output voltage is sent to a control unit (not shown) of the image forming apparatus 1. The control unit continuously grasps the toner adhesion amount of the reference pattern based on the regular reflection light amount and the diffuse reflection light amount obtained from the output voltages of the photodiodes 80B and 80C. Compare the target adhesion amount. Based on the comparison result, the control unit functions as an image density control unit, and the laser light intensity of the laser writing unit 22, the charging bias of the charging roller 9, the developing bias applied to the developing sleeve 32, and the developer supply The developer supply amount from the apparatus 35 is appropriately changed, and the image density is adjusted to a desired density.

  As described above, according to the present invention, the optical sensor 99 described above is provided as an optical sensor for detecting the toner adhesion amount of the density detection toner patch 90 (reference pattern) formed on the surface 29 a of the transport belt 29. Therefore, the optical axis deviation in each optical component 80 can be adjusted to make the direction of the optical axis constant, so that the amount of toner adhering as powder can be detected accurately, and the adjustment of the image density is accurate. Can be.

  In the above-described embodiment, the optical sensor 99 is disposed relative to the surface 29 a of the conveyance belt 29, and the toner adhesion amount of the density detection toner patch 90 formed on the surface 29 a of the conveyance belt 29 is optically measured. Although the detection is performed by the sensor 99, instead of such an arrangement of the optical sensor 99, for example, as shown in FIG. You may arrange | position relatively. The optical sensor 99 detects the toner adhesion amount of the density detection toner patch 90 formed along the surface movement direction of the photosensitive drum 8. Further, in an image forming apparatus provided with an intermediate transfer belt as an intermediate transfer member, an optical sensor 99 is disposed relative to the intermediate transfer belt, and a density detection toner patch formed on the surface of the primary transfer belt. A toner adhesion amount of 90 may be detected.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

It is a front view which shows the optical component holder which concerns on one Embodiment of this invention. It is a cross-sectional perspective view which follows the XX line of FIG. It is a figure explaining the position of the 1st holding member and the 2nd holding member when the optical component holder of FIG. 1 is seen from the front. It is a cross-sectional perspective view which shows the state in which the optical component holder of FIG. 1 hold | maintained the optical component without a shift | offset | difference of an optical axis. It is a cross-sectional perspective view which shows the state (before optical axis adjustment) which the optical component holder of FIG. 1 hold | maintained the optical component with a shift | offset | difference of an optical axis. It is a cross-sectional perspective view which shows the state (after optical axis adjustment) which the optical component holder of FIG. 1 hold | maintained the optical component with a shift | offset | difference of an optical axis. It is a cross-sectional perspective view which shows the state (after optical axis adjustment) in which the optical component holder of FIG. It is a cross-sectional perspective view which shows the structure of the 1st modification of the optical component holder of FIG. It is a figure explaining the position of the 1st holding member and the 2nd holding member when the optical component holder of FIG. 8 is seen from the front. It is a cross-sectional perspective view which shows the structure of the 2nd modification of the optical component holder of FIG. It is a figure explaining the position of the 1st holding member and the 2nd holding member when the optical component holder of FIG. 10 is seen from the front. It is a cross-sectional perspective view which shows the structure of the 3rd modification of the optical component holder of FIG. It is a figure explaining the position of the 1st holding member and the 2nd holding member when the optical component holder of FIG. 12 is seen from the front. It is sectional drawing which shows the optical sensor which concerns on one Embodiment of this invention. 1 is a cross-sectional view illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 16 is a cross-sectional view illustrating a process cartridge included in the image forming apparatus of FIG. 15. FIG. 17 is a cross-sectional view showing a configuration of a modified example of the process cartridge of FIG. 16.

Explanation of symbols

1 Image forming apparatus 29 Conveyor belt (image carrier)
29a Conveyor belt surface (image carrier surface)
36 Toner (Powder)
70, 70A, 70B, 70C Optical component holder 71 Case 71a Case outer surface 72 Housing hole 72a Inner surface of housing hole 73 Optical path regulating member 74, 74A First holding member 741 Supporting point 741a Inner edge of supporting point 75, 75A Second holding member 76 Movable protrusion (protrusion)
761 Through-hole 762 Movable element 77 Support point 77a Tip of support point 78 Elastic protrusion (protrusion)
80 Optical parts 80A Light emitting diode (optical parts)
80B, 80C Photodiode (optical component)
DESCRIPTION OF SYMBOLS 81 Optical element 82 A pair of lead wire 83 Sealing member 84 Head 85 Body 86 Flange part 99 Optical sensor F1 The surface enclosed by the inner edge of a support part F2 The surface enclosed by the front-end | tip of several support parts L The optical axis of an optical component M Shaft of optical component body N Shaft of receiving hole

Claims (9)

In an optical component holder for holding a bullet-shaped optical component,
Case and
A housing hole having an inner diameter formed larger than the outer diameter of the barrel of the optical component, provided through the case;
A first holding member provided on the inner surface of the accommodation hole, having a fulcrum protruding annularly over the circumferential direction of the inner surface of the accommodation hole;
The inner surface of the housing hole is separated from the first holding member along the axial direction of the housing hole, and has three or more projecting portions projecting away from each other along the circumferential direction of the inner surface of the housing hole. A second holding member provided,
Is provided,
The fulcrum portion is formed such that a surface surrounded by an inner edge thereof is included in a transverse section of the barrel portion of the optical component, and
The optical component holder, wherein the plurality of protrusions are movable protrusions capable of changing a protrusion amount from the inner surface of the accommodation hole. In an optical component holder for holding a bullet-shaped optical component,
Case and
A housing hole having an inner diameter formed larger than the outer diameter of the barrel of the optical component, provided through the case;
A first holding member provided on the inner surface of the housing hole, having a plurality of three or more fulcrum portions protruding apart from each other along the circumferential direction of the inner surface of the housing hole;
The inner surface of the housing hole is separated from the first holding member along the axial direction of the housing hole, and has three or more projecting portions projecting away from each other along the circumferential direction of the inner surface of the housing hole. A second holding member provided,
Is provided,
The plurality of fulcrum portions are formed such that a surface surrounded by their tips is included in a transverse section of the barrel of the optical component, and
The optical component holder, wherein the plurality of protrusions are movable protrusions capable of changing a protrusion amount from the inner surface of the accommodation hole.   A through hole provided through the inner surface of the housing hole and the outer surface of the case; and a movable element that can project and retract into an opening of the inner surface of the housing hole in the through hole. The optical component holder according to claim 1, wherein the optical component holder is provided.   The optical component holder according to claim 3, wherein a length of the movable element is shorter than a length of the through hole.   A screw groove is provided on the inner peripheral surface of the through hole, and a screw thread that is screwed into the screw groove provided on the inner surface of the through hole is provided on the outer peripheral surface of the mover. The optical component holder according to claim 3 or 4, wherein the optical component holder is provided.   The fixing member which fixes the said needle | mover to the said through-hole after the said optical component is hold | maintained by the said 1st holding member and the said 2nd holding member is provided. The optical component holder according to any one of the above.   The at least 1 protrusion part is replaced with the said movable protrusion part, and is made into the elastic protrusion part comprised with the elastic body among these several protrusion parts. The optical component holder according to 1.   An optical sensor comprising an optical component and an optical component holder for holding the optical component, wherein the optical component holder includes the optical component holder according to any one of claims 1 to 7. An optical sensor.   In the image forming apparatus having at least an image carrier on which powder is adhered to the surface, and an optical sensor for detecting the amount of the powder adhered to the surface of the image carrier, the optical sensor includes: An image forming apparatus comprising the optical sensor according to claim 8.

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