JP5485463B1 - Optical member, exposure apparatus, and image forming apparatus - Google Patents

Abstract

An optical member, an exposure apparatus, and an image forming apparatus capable of suppressing variations in the posture of a cylindrical lens.
A rod lens 54 stacked between a pair of side plates is positioned by contacting another member at three locations. Since the rod lens 54 is positioned in contact with the other member at three positions, the rod lens 54 is in contact with the other member at three positions even when the shape of each component varies. For this reason, it is suppressed that the attitude | position of the rod lens 54 varies compared with the case where the rod lens 54 is positioned in contact with other members at four or more locations.
[Selection] Figure 1

Description

  The present invention relates to an optical member, an exposure apparatus, and an image forming apparatus.

  The manufacturing method of the rod lens array (optical member) described in Patent Document 1 includes a step of arranging the first array, a step of arranging the second array on the first array A, and The step of temporarily fixing in this state, the step of moving the first and second array bodies in an overlapped state, and the second array body are maintained in a relative position with respect to the first array body in the array direction of the rod lenses. However, the step of separating from the first array, the step of applying an adhesive to at least one of the first and second arrays, and the adhesive being interposed between the first and second arrays In this state, the method further comprises a step of placing the first array body again on the second array body and bonding the first and second array bodies.

JP 2010-015144 A

  An object of the present invention is to suppress variations in the posture of a cylindrical lens.

An optical member according to claim 1 of the present invention includes a pair of long side plates disposed opposite to each other, and columnar lenses arranged in two rows in contact with the side plates between the pair of side plates. A lens arranged at least at both ends of the lens constituting one row is in contact with only one side plate and two adjacent lenses in the other row, and has an end surface radius at one end of the lens. Is smaller than the end face radius of the other end, and the lens having one end facing one side and the lens having the other end facing one are regularly arranged .

The optical member according to claim 2 of the present invention is an optical member according to claim 1, wherein one of the rows, the one end is constituted by the lens facing one, the other row, the other end The part is composed of the lens facing one side.

An exposure apparatus according to claim 3 of the present invention includes a substrate on which a light emitting element is mounted, a lens through which light emitted from the light emitting element is transmitted, the optical member according to claim 1 , the substrate, and the substrate A housing for holding the optical member.

According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising: an image carrier; and the exposure device according to the third aspect , wherein the image carrier is exposed to form an electrostatic latent image, and the exposure device is formed. And a developing device for developing the electrostatic latent image.

According to the optical member of the first aspect of the present invention, the optical axis direction of the lens is different from the case where the lens having one end facing one side and the lens having the other end facing one are irregularly arranged. The variation can be suppressed.

According to the optical member of claim 2 of the present invention, the optical axis direction of the lens is compared with the case where one row is constituted by a lens having one end facing one side and a lens having the other end facing one. The variation can be suppressed.

According to the exposure apparatus of the third aspect of the present invention, the deviation of the exposure point can be suppressed as compared with the case where the optical member according to the first or second aspect is not provided.

According to the image forming apparatus of the fourth aspect of the present invention, the quality of the output image can be improved as compared with the case where the exposure apparatus according to the third aspect is not provided.

FIG. 3 is a plan view showing a lens array according to the first embodiment. (A) (B) It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. (A) (B) It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. (A) (B) It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. (A) (B) It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. It is process drawing which showed the process for manufacturing the lens array which concerns on this 1st Embodiment. It is the perspective view which showed the lens material used for manufacturing the lens array which concerns on this 1st Embodiment. (A) (B) It is sectional drawing which showed the LED print head concerning this 1st Embodiment. (A) (B) It is sectional drawing which showed the LED print head concerning this 1st Embodiment. It is the disassembled perspective view which showed the LED print head which concerns on this 1st Embodiment. It is the perspective view which showed the LED print head which concerns on this 1st Embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment. (A) (B) It is the top view which showed the lens array which concerns on the 1st comparative form with respect to the lens array which concerns on this 1st Embodiment, and the lens array which concerns on a 2nd comparative form. It is the top view which showed the lens array which concerns on this 2nd Embodiment. (A) (B) It is process drawing which showed the process for manufacturing the lens array which concerns on this 2nd Embodiment. (A) (B) It is the top view which showed the lens array which concerns on this 3rd Embodiment and this 4th Embodiment.

<First Embodiment>
An example of an optical member, an exposure apparatus, and an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. In addition, arrow UP shown in each figure shows the vertical direction upper direction.

(overall structure)
As shown in FIG. 14, the apparatus main body 10 </ b> A of the image forming apparatus 10 constitutes a transfer unit 32, is stretched around a plurality of rollers 12, and is conveyed in the direction of arrow A by driving a motor (not shown). An endless belt-like intermediate transfer belt 14 is provided.

  The image forming apparatus 10 includes image forming units 28Y, 28M, 28C, and 28K that form toner images corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K). It is disposed along the longitudinal direction of the transfer belt 14, and is supported by the apparatus main body 10A so as to be detachable.

  In addition, about the member provided in each color, the alphabet (Y / M / C / K) which shows each color is attached | subjected to the end of a code | symbol, but when it demonstrates without distinguishing especially a color, this The explanation will be made by omitting the alphabet at the end.

[Image forming unit]
The image forming unit 28 includes a photosensitive drum 16 as an example of an image holding member that is rotated clockwise by a driving unit including a motor and a gear (not shown). Further, a charging roller 18 that uniformly charges the surface of the photosensitive drum 16 to a predetermined potential is disposed on the peripheral surface of the photosensitive drum 16. Specifically, the charging roller 18 is a conductive roller, and the circumferential surface thereof is in contact with the circumferential surface of the photosensitive drum 16, and the axial direction of the charging roller 18 and the axial direction of the photosensitive drum 16 are parallel to each other. It is arranged to become.

  Further, an LED print head as an example of an exposure apparatus that irradiates light onto the photosensitive drum 16 to form an electrostatic latent image on the circumferential surface downstream of the charging roller 18 in the rotation direction of the photosensitive drum 16. 20 (hereinafter simply referred to as “print head 20”) extends in the axial direction of the photosensitive drum 16. The print head 20 forms an electrostatic latent image on the photosensitive drum 16 by irradiating the photosensitive drum 16 with a light beam in accordance with image data. Details of the print head 20 will be described later.

  Further, an electrostatic latent image formed on the photosensitive drum 16 is formed in a predetermined color (yellow / magenta / cyan / cyan) on the circumferential surface downstream of the print head 20 in the rotation direction of each photosensitive drum 16. A developing device 22 as an example of a developing device that forms a toner image by developing with black toner is disposed.

  The developing device 22 has a cylindrical developing roller 24 that is disposed in the vicinity of the photosensitive drum 16 and is rotatably provided. A developing bias is applied to the developing roller 24 so that the toner loaded in the developing device 22 adheres to the developing roller 24. Further, the toner attached to the developing roller 24 is conveyed to the surface of the photosensitive drum 16 by the rotation of the developing roller 24, and the electrostatic latent image formed on the photosensitive drum 16 is developed as a donor image. ing.

  A cleaning blade 26 that collects residual toner on the photosensitive drum 16 is disposed on the peripheral surface downstream of a transfer roller 30 described later in the rotation direction of the photosensitive drum 16. The cleaning blade 26 is arranged so that one side is in contact with the photosensitive drum 16, and the toner remaining on the photosensitive drum 16 without being transferred to the intermediate transfer belt 14 by the transfer roller 30 or the photosensitive member at the time of transfer. The toner of other colors that have adhered to the drum 16 is scraped off and collected.

[Transfer unit]
A transfer roller 30 constituting a transfer unit 32 is disposed on the opposite side of the photosensitive drum 16 with the intermediate transfer belt 14 interposed therebetween on the peripheral surface downstream of the developing device 22 in the rotation direction of each photosensitive drum 16. Has been.

  The transfer roller 30 is charged to a predetermined potential and rotates counterclockwise to convey the intermediate transfer belt 14 at a predetermined speed, and presses the intermediate transfer belt 14 against the photosensitive drum 16. As a result, the transfer roller 30 transfers the toner image on the photosensitive drum 16 onto the intermediate transfer belt 14.

  Here, toner images of different colors formed by the image forming units 28 are transferred onto the belt surface of the intermediate transfer belt 14 so as to overlap each other. As a result, a color toner image is formed on the intermediate transfer belt 14. In the present embodiment, the toner image in which the four color toner images are transferred in a superimposed manner is referred to as a “final toner image”.

  In contrast, a transfer device 34 including two rollers 34 </ b> A and 34 </ b> B facing each other is disposed on the downstream side of the photosensitive drum 16 of each color in the conveyance direction of the intermediate transfer belt 14. Then, the final toner image formed on the intermediate transfer belt 14 on the sheet member P taken out from the paper tray 36 provided at the bottom of the image forming apparatus 10 and conveyed between the rollers 34A and 34B. Is to be transcribed.

  On the other hand, on the downstream side of the transfer device 34 in the transport direction of the intermediate transfer belt 14, a cleaner 42 that collects the toner that has not been transferred to the sheet member P by the transfer device 34 and remains on the intermediate transfer belt 14 is provided. It has been. The cleaner 42 is provided with a blade 44 that comes into contact with the intermediate transfer belt 14, and collects the toner by scraping the remaining toner.

[Fusing unit]
Further, a fixing unit 38 is provided in the conveyance path of the sheet member P to which the final toner image has been transferred. The fixing unit 38 includes a fixing device 40 that includes a heating roller 40A and a pressure roller 40B. The sheet member P conveyed to the fixing device 40 is nipped and conveyed by the heating roller 40A and the pressure roller 40B, so that the toner on the sheet member P melts and is pressed against the sheet member P to be pressed. Has become established.

(Operation of the overall configuration)
In the image forming apparatus 10, an image is formed as follows.

  First, the charging roller 18 uniformly negatively charges the surface of the photosensitive drum 16 with a predetermined charging portion potential. Further, exposure is performed by the print head 20 so that the image portion on the charged photosensitive drum 16 has a predetermined exposure portion potential, and an electrostatic latent image is formed on the photosensitive drum 16.

  When the electrostatic latent image on the rotating photosensitive drum 16 passes through the developing roller 24 provided in the developing device 22, the toner of the developer adheres to the electrostatic latent image, and the electrostatic latent image becomes a toner image. Visualized.

  The visualized toner images of the respective colors are sequentially transferred to the intermediate transfer belt 14 by the electrostatic force of the transfer roller 30, and a color final toner image is formed on the intermediate transfer belt 14.

  The final toner image is sent between rollers 34A and 34B provided in the transfer device 34. The final toner image is transferred from the sheet tray 36 and transferred to the sheet member P that has been conveyed between the rollers 34A and 34B.

  Further, the toner image transferred to the sheet member P is fixed to the sheet member P by the fixing device 40, and the sheet member P is discharged outside the device.

(Print head)
Next, the print head 20 will be described.

  The print head 20 extends in one direction and has a long shape. The print head 20 extends along the rotation axis direction of the photosensitive drum 16 (see FIG. 14) (hereinafter simply referred to as “drum axis direction”) in a state where the print head 20 is attached to the apparatus main body 10A. Are arranged as follows. That is, with the print head 20 attached to the apparatus main body 10A, the print head 20 extending in one direction is attached to the apparatus main body 10A so as to extend in the drum axis direction (see FIG. 13).

  As shown in FIG. 12, the print head 20 extending in one direction (the direction of arrow D in the figure) includes a printed wiring board 52 on which a light emitting diode array 62 (LED array) as an example of a light emitting element is mounted. I have. Specifically, the printed wiring board 52 is configured by mounting a light emitting diode array 62 on the wiring board 50.

  Further, the print head 20 includes rod lenses 54 as an example of cylindrical lenses that transmit light emitted from light emitting points (LED: Light Emitting Diode) of the light emitting diode array 62 and are arranged in one direction. A lens array 56 as an example of an extending optical member is provided. The print head 20 includes a housing 58 extending in one direction to which the printed wiring board 52 and the lens array 56 are fixed.

[Printed wiring board]
The printed wiring board 52 extends in one direction and has a rectangular shape when viewed from the plate surface direction. Then, as shown in FIG. 12, a light emitting diode array 62 in which a plurality of (for example, 128) light emitting diodes (LEDs) are linearly provided on one surface of the printed wiring board 52 is staggered. Has been implemented. On the other hand, an electronic component 64 for controlling the light emitting diode array 62 is mounted on the other surface of the printed wiring board 52 as shown in FIG.

[Lens Array]
As shown in FIG. 12, the lens array 56 extends in one direction. In the lens array 56, a plurality of rod lenses 54 through which light emitted from the light emitting diode array 62 is transmitted are arranged in a staggered manner. Thus, the light emitted from the light emitting diode array 62 and transmitted through the rod lens 54 forms an image on the photosensitive drum 16 (see FIG. 14). Details of the lens array 56 will be described later.

[Case]
The housing 58 extends in one direction as shown in FIG. And the cross section of the housing | casing 58 which cross | intersects with respect to one direction passes the gravity center G of the housing | casing 58, and the optical axis direction (arrow shown in each figure) of the rod lens 54 is shown in FIG. E direction: hereinafter referred to simply as “lens axial direction”) is symmetrical with respect to a line J extending.

  The housing 58 is formed with a through hole 76 that extends in one direction and penetrates the housing 58 in the lens axis direction. Furthermore, the housing 58 is formed on one end side in the lens axis direction (upper side in the figure), and is formed on the lens fixing portion 74 to which the lens array 56 is fixed, and on the other end side in the lens axis direction (lower side in the figure). And a board fixing part 72 to which the printed wiring board 52 is fixed, and a main body part 70 formed between the board fixing part 72 and the lens fixing part 74.

  11B, the lens array 56 is fixed to one end side (upper side in the drawing) of the through hole 76 in the lens axis direction, and the other end side of the through hole 76 in the lens axis direction (see FIG. 11B). The printed wiring board 52 is fixed to the middle lower side. In the state where the lens array 56 and the printed wiring board 52 are fixed to the housing 58, the rod lens 54 of the lens array 56 and the light emitting diode array 62 mounted on one surface of the printed wiring board 52 include a lens. It is to be opposed in the axial direction.

[Main unit]
The main body 70 is a frame extending in one direction. As shown in FIG. 11A, the cross section of the main body 70 intersecting the one direction is such that the lens fixing portion 74 side is on the substrate fixing portion 72 side. On the other hand, it has a narrow trapezoidal shape. Further, the body portion 70 is formed with a passage portion 76 </ b> A through which light emitted from the light emitting diode array 62 toward the rod lens 54 passes and which constitutes a part of the through hole 76.

  Further, the end surface 70A of the main body portion 70 formed so as to surround the opening edge 78 on the board fixing portion 72 side in the passage portion 76A comes into contact with the plate surface of the printed wiring board 52 fixed to the housing 58. ing.

[Lens fixing part]
The lens fixing portion 74 is a frame extending in one direction. As shown in FIG. 11A, the lens fixing portion 74 is open at one end side in the lens axial direction and has a part of the through hole 76 formed therein. A hollow portion 76B is formed, in which the lens array 56 is disposed.

  This hollow portion 76B will be described later from one direction and the width direction of the lens array 56 orthogonal to the one direction and the lens axis direction (arrow F direction shown in each drawing: hereinafter simply referred to as “lens width direction”). It is formed by being surrounded by the protrusion 86 and the protrusion 88.

  Specifically, as shown in FIG. 10A, the lens fixing portion 74 includes protrusions 86 that respectively protrude from one end in one direction of the main body 70 to one end in the lens axial direction (see FIG. 10A). 10 (A) shows only one side). Furthermore, as shown in FIG. 11A, the lens fixing portion 74 includes protrusions 88 that protrude from both end portions in the lens width direction of the main body portion 70 to one end in the lens axial direction. Then, both end portions of each protrusion 88 in one direction are connected to both end portions of each protrusion 86 in the lens width direction. Accordingly, as described above, the lens fixing portion 74 is a frame extending in one direction.

  On the other hand, the end portion in one direction of the lens array 56 fixed to the lens fixing portion 74 and the protrusion 86 are separated in one direction as shown in FIG. (Only one side is shown in FIG. 10B). Then, the tip of a nozzle (not shown) used for applying a sealing material 94 that seals the gap between the lens fixing portion 74 (housing 58) and the lens array 56 is inserted into the separation portion 92. It has become so.

[Board fixing part]
The substrate fixing portion 72 is a frame extending in one direction, and the other end portion in the lens axis direction is opened in the substrate fixing portion 72 as shown in FIG. A cavity portion 76C is formed, which constitutes the portion and in which the printed wiring board 52 is disposed.

  The hollow portion 76C is formed by being surrounded by a projection 80 and a projection 82 described later from the lens width direction and one direction.

  Specifically, as shown in FIG. 10A, the substrate fixing portion 72 includes protrusions 80 that respectively protrude from both end portions in one direction of the main body portion 70 to the other end in the lens axial direction (see FIG. 10A). FIG. 10A shows only one side). Furthermore, as shown in FIG. 11A, the substrate fixing portion 72 includes protrusions 82 that protrude from the both end portions in the lens width direction of the main body portion 70 to the other end in the lens axial direction. Then, both end portions in one direction of each protrusion 82 are connected to both end portions in the lens width direction of each protrusion 80. Steps are formed in the protrusions 82 and 80 and the main body 70, and the step is the above-described end surface 70 </ b> A that comes into contact with the outer peripheral plate surface of the printed wiring board 52.

(Main part configuration)
Next, the configuration of the lens array 56 will be described.

  As shown in FIG. 1, the lens array 56 includes a frame 102 extending in one direction. The frame 102 extending in one direction is composed of a pair of long side plates 104 arranged opposite to each other, and a pair of closing plates 106 that are inclined with respect to the lens width direction and close both ends of the pair of side plates 104. It is configured.

  The columnar rod lenses 54 are made of glass, and are arranged in two rows in contact with the side plate 104 inside the frame 102. Further, the end surface radius of one end portion of each rod lens 54 in the optical axis direction is made smaller than the end surface radius of the other end portion. In each figure, dots are given to the end face 54A at one end, and the end face 54B at the other end is shown in white (no dots).

  One column (the column on the right side in the figure) is composed of a rod lens 54 whose end face 54A at one end faces the front side in the figure (hereinafter simply described as “one end part faces the front side in the figure”). The other column (the column on the left side in the figure) is composed of rod lenses 54 whose end face 54B at the other end faces the front side in the figure (hereinafter simply referred to as “the other end part faces the front side in the figure”). Has been.

  In addition, the rod lens 54 constituting one row, except for the rod lens 54 arranged at the lower end portion in the figure, the side plate 104 on one side (right side in the figure) and two adjacent rods in the other row. It is in contact only with the lens 54. Further, the rod lens 54 disposed at the lower end in the drawing is in contact with only one side plate 104, the other row of rod lenses 54, and one (lower in the drawing) closing plate 106. That is, the rod lenses 54 constituting one row are arranged apart from each other and are in contact with other members at three locations. That is, in the rod lens 54 constituting one row, the rod lenses 54 arranged at least other than both ends are in contact with only one side plate 104 and two adjacent rod lenses 54 in the other row.

  On the other hand, the rod lens 54 constituting the other row constitutes one row excluding the rod lens 54 arranged at the lower end portion in the drawing except for the rod lens 54 arranged at the upper end portion in the drawing. The rod lens 54 has the same configuration. In other words, the rod lens 54 constituting the other row, except for the rod lens 54 arranged at the upper end portion in the figure, the side plate 104 on the other side (left side in the figure) and two adjacent rods in one row. It is in contact only with the lens 54.

  Further, in the rod lens 54 constituting the other row, the rod lens 54 disposed at the upper end portion in the drawing includes the other side plate 104, the rod lens 54 in one row, and the closing plate 106 in the other (upper portion in the drawing). Only touching.

  That is, the rod lenses 54 constituting the other row are arranged so as to be separated from each other and are in contact with the other members at three positions, similarly to the rod lenses 54 constituting the one row. That is, the rod lenses 54 arranged at least other than both ends in the rod lens 54 constituting the other row are in contact only with the other side plate 104 and two adjacent rod lenses 54 in one row. As a result, the rod lens 54 having one end facing the front side in the figure is not in contact with the rod lens 54 having one end facing the front side in the figure, and the rod lens 54 having the other end facing the front side in the figure. Touching. Similarly, the rod lens 54 with the other end facing the front side in the figure is not in contact with the rod lens 54 with the other end facing the front side in the figure, and the rod lens 54 with one end facing the front side in the figure. Is in contact with.

  In this manner, the distance L between the pair of side plates 104 (see the drawing) is determined so that all the rod lenses 54 arranged in two rows come into contact with other members at three positions. Specifically, the distance L is determined so as to satisfy the following formula (1), where r is the radius of the lens material 154 forming the rod lens 54 by being divided in the optical axis direction. The lens material 154 and the radius r of the lens material 154 will be described later.

2r <L <(2 + √3) r Expression (1)
Here, the first comparative example in which the distance L between the pair of side plates 104 is 2r and the second comparative example in which the distance L between the pair of side plates 104 is (2 + √3) r are shown in FIGS. ). In the first comparative example and the second comparative example, for the sake of convenience, the rod lens 300 having the same end face radius at the one end and the end face radius at the other end is used, and the radius of the rod lens 300 is the radius of the lens material. Used as r.

  In the first comparative example, as shown in FIG. 15A, the distance L between the pair of side plates 104 is 2r, and therefore the rod lenses 300 are arranged in a row between the pair of side plates 104. One rod lens 300 is in contact with both side plates 104 and the upper and lower rod lenses 300 in the drawing. That is, in the first comparative example, the rod lens 300 is in contact with other members at four locations.

  In the second comparative example, as shown in FIG. 15B, the distance L between the pair of side plates 104 is (2 + √3) r. Therefore, the distance (N in the figure) between the center of the rod lens 300 in one row and the center of the other rod lens 300 in the lens width direction is √3r. Then, the triangle S formed by connecting the center of the rod lens 300 in the other row and the center of two adjacent rod lenses 300 in the one row becomes a regular triangle having a side of 2r. Thereby, the rod lens 300 constituting one row is in contact with the upper and lower rod lenses 300 constituting the one row, the two adjacent rod lenses 300 in the other row, and the one side plate 104. . That is, in the second comparative example, the rod lens 300 is in contact with other members at five locations.

  However, the distance L between the pair of side plates 104 according to the first embodiment satisfies the above-described formula (1). Therefore, in this embodiment, the rod lens 300 does not contact both side plates 104 as in the first comparative example, and the rod lens 54 contacts only one side plate 104. Further, as in the second comparative example, the rod lenses 300 constituting one row are separated without contacting the upper and lower rod lenses 300 constituting the one row.

  Thereby, the rod lens 54 of this embodiment comes in contact with other members at three locations as described above.

(Effects of main components)
Next, the operation of the main configuration will be described using a lens array manufacturing method for manufacturing the lens array 56.

[Side plate placement process]
As shown in FIGS. 2A and 6, a pair of side plate materials 114 that become the side plates 104 by being divided in a division step described later are arranged to face each other so that the plate surfaces face the horizontal direction. . At this time, the pair of side plate members 114 is arranged so that the distance L between the pair of side plate members 114 satisfies the above-described formula (1).

  Further, the closing plate material 116A that becomes the closing plate 106 by being divided in a dividing step described later is disposed so as to be bridged between the lower ends of the pair of side plate materials 114 so as to close the bottoms of the pair of side plate materials 114. . In this state, the closing plate material 116A is inclined with respect to the horizontal direction, and the upper side of the pair of side plate materials 114 is open.

[Stacking process]
As shown in FIG. 2A and FIG. 6, a long cylindrical shape that becomes a rod lens 54 is formed above a pair of side plate members 114 arranged to face each other by being divided in a division step described later. A supply device 120 for supplying the lens material 154 between the pair of side plate materials 114 is disposed.

  Here, the lens material 154 is made of glass, and as shown in FIG. 9, the end surface radius of one end of the lens material 154 in the optical axis direction is smaller than the end surface radius of the other end. It is said that. In each figure, dots are attached to the end face 154A at one end, and the end face 154B at the other end is shown in white (no dots). The radius r of the lens material 154 in the longitudinal direction of the lens material 154 is used as the radius r of the lens material 154 of the formula (1). As an example, the length of the lens material 154 in the lens axial direction is 300 [mm], the end surface radius of one end of the lens material 154 is 0.150 [mm], and the other end of the lens material 154 The end surface radius of the part is 0.151 [mm]. Further, the rod lens 54 is formed by dividing the lens material 154 into 69 pieces in the lens axial direction.

  2 (B), 3 (A) (B), 4 (A) and 4 (B), a lens material 154 with one end facing the front side of the paper surface, and the other end portion of the paper surface. The lens material 154 facing the front side is alternately supplied from the supply device 120 between the pair of side plate materials 114. Further, the lens material 154 is stacked from above so that the optical axis is oriented in the horizontal direction.

  Here, since the closing plate material 116A is inclined with respect to the horizontal direction so that the right side of the paper surface is downward, the lens material 154 supplied first between the side plate materials 114 is supplied to the right side of the paper surface and then supplied. The lens material 154 is supplied to the left side of the drawing. In this manner, the lens material 154 is alternately supplied to the right side and the left side of the paper.

  Thus, the lens material 154 is arranged in two rows between the pair of side plate materials 114, and one row (the right row in the drawing) is the lens material 154 in which one end portion of the lens material 154 faces the front side in the drawing. Composed. On the other hand, the other column (the column on the left side in the figure) is composed of the lens material 154 with the other end portion of the lens material 154 facing the front side in the diagram, and the lens material 154 is regularly arranged.

[Closing process]
As shown in FIG. 5A, when the supply of the lens material 154 between the pair of side plate materials 114 is completed, the closing plate material 116B is closed to the pair of side plate materials 114 so as to close the opening between the pair of side plate materials 114. It is bridged over the upper end of the. In this state, the closing plate material 116B is inclined with respect to the horizontal direction similarly to the closing plate material 116A, and is in contact with the lens material 154 disposed at the top in the other row.

  In this way, the lens materials 154 are arranged in two rows inside the frame member 122 formed of the pair of closing plate members 116 formed of the closing plate member 116A and the closing plate member 116B, and the pair of side plate members 114. . Similarly to the description of the arrangement of the rod lens 54, the lens members 154 constituting one row are arranged so as to be separated from each other and in contact with the other members at three positions. Further, the lens members 154 constituting the other row are arranged so as to be separated from each other and in contact with other members at three positions.

  Further, the lens material 154 whose one end portion faces the front side in the drawing is in contact with the lens material 154 whose one end portion faces the front side in the drawing without contacting the lens material 154 whose one end portion faces the front side in the drawing. . Similarly, the lens material 154 having the other end portion facing the front side in the figure has a lens material 154 having the other end portion facing the front side in the drawing without contacting the lens material 154 having the other end portion facing the front side in the drawing. Touch.

[Filling process]
As shown in FIGS. 5A and 5B and FIG. 7, a resin material 140 (for example, silicon resin) is filled (vacuum impregnated) between the lens materials 154 stacked between the pair of side plate materials 114. . The lens material 154 is fixed to the frame material 122 by curing the filled resin material 140.

[Division process / Polishing process]
As shown in FIGS. 7 and 8, in a state where the lens material 154 is fixed inside the frame material 122, the lens material 154 is used together with the frame material 122 by using a split blade (not shown). Dividing into a plurality of pieces in the axial direction (dividing step). Then, the end surface of the lens material 154 cut after the division is polished to manufacture the lens array 56 (polishing step).

  Specifically, the frame material 122 is divided to form the frame 102, and the lens material 154 is divided to form the rod lens 54.

[Others]
A method for manufacturing the print head 20 using the lens array 56 to manufacture the print head 20 will be described. First, the light emitting diode array 62 is mounted on the wiring board 50 (see FIG. 12). Further, the printed wiring board 52 (wiring board 50) and the lens array 56 are used with a fixing agent (not shown) so that the lens array 56 manufactured by the above-described lens array manufacturing method and the light emitting diode array 62 face each other. It is fixed to the housing 58. Further, the gap between the housing 58 and the lens array 56 is sealed with a sealing material 94 to manufacture the print head 20 (see FIGS. 10B, 11B, and 13).

[Summary]
As described above, when the lens array 56 is manufactured, the lens material 154 is disposed between the pair of side plate materials 114 by stacking the lens material 154 between the pair of side plate materials 114. For this reason, compared with the case where a lens material is arrange | positioned by arranging a lens material in a horizontal direction, a manufacturing cost is reduced.

  Further, when the lens array 56 is manufactured, the pair of side plate materials 114 are arranged so that the distance L between the pair of side plate materials 114 satisfies the value of the above-described formula (1). For this reason, the lens material 154 stacked between the pair of side plate members 114 is positioned by contacting with other members at three locations.

  Further, since the lens material 154 (rod lens 54) is positioned in contact with the other member at three positions, the lens material 154 (rod lens 54) is another member even when the shape of each component varies. And three places. For this reason, as compared with the case where the lens material 154 (rod lens 54) is positioned in contact with other members at four or more locations, the posture of the lens material 154 (rod lens 54) is suppressed from varying.

  In addition, one row is configured by a lens material 154 (rod lens 54) having one end portion facing the front side in the drawing, and the other row is a lens material 154 (rod lens 54) having the other end portion facing the front side in the drawing. ). Thus, the lens material 154 (rod lens 54) whose one end portion faces the front side in the drawing and the lens material 154 (rod lens 54) whose other end portion faces the front side in the drawing are regularly arranged. Variations in the optical axis direction of the rod lens 54 (lens material 154) are suppressed.

  Further, the lens material 154 (rod lens 54) having one end (the other end) facing the front side in the drawing is the lens material 154 (rod lens 54) having the one end (the other end portion) facing the front side in the drawing. The other end portion (one end portion) is in contact with the lens material 154 (rod lens 54) facing the front side in the drawing without contacting with the lens. Therefore, the lens material 154 (rod lens 54) is prevented from being arranged in a fan shape (one is widened and the other is narrowed), and the optical axis direction of the lens material 154 (rod lens 54) varies. Is suppressed.

  Further, regarding the print head 20, the quality of the electrostatic latent image formed on the photosensitive drum 16 is improved by suppressing the variation of the posture of the rod lens 54.

  Further, with respect to the image forming apparatus 10, the quality of the electrostatic latent image formed on the photosensitive drum 16 is improved, so that the image quality output from the image forming apparatus 10 is improved.

Second Embodiment
Next, an example of an optical member, an exposure apparatus, and an image forming apparatus image according to the second embodiment of the present invention will be described with reference to FIGS. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a different part from 1st Embodiment is mainly demonstrated.

  As shown in FIG. 16, no closing plate is provided at both ends of the pair of side plates 104 provided in the lens array 200 as an example of the optical member according to the second embodiment. The rectangular shape is viewed from the lens axis direction. In addition, at both ends of the lens array 200, a part of the rod lens 54 is cut, and a residual material 202 not presenting the rod lens is disposed.

  In this configuration, the rod lenses 54 arranged at least at both ends of the rod lens 54 constituting one row are in contact with only one side plate 104 and two adjacent rod lenses 54 in the other row. Similarly, the rod lenses 54 arranged at least other than both ends in the rod lens 54 constituting the other row are in contact only with the other side plate 104 and two adjacent rod lenses 54 in one row.

  In the lens array manufacturing method for manufacturing the lens array 200, as shown in FIGS. 17A and 17B, a cutting blade (not shown) is used after the polishing step described in the first embodiment. A step of cutting both ends of the lens array 56 is provided (end cutting step).

  As described above, the lens array 200 is manufactured by cutting both ends of the lens array 56. For this reason, it is possible to manufacture a plurality of types of lens arrays 200 having different lengths by changing the cutting position. Further, the lens array 200 is downsized as compared with the case where both end portions are not excised. Furthermore, as the lens array 200 is reduced in size, the print head 20 is also reduced in size.

  Other operations are the same as those in the first embodiment.

<Third Embodiment>
Next, an example of an optical member, an exposure apparatus, and an image forming apparatus image according to the third embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a different part from 1st Embodiment is mainly demonstrated.

  As for one column (the right column in the figure) of the lens array 220 as an example of the optical member according to the third embodiment, the rod lens 54 having one end facing the front side in the figure and the other end part in the front in the figure. The rod lenses 54 facing the side are alternately arranged. The other column (the left column in the figure) has the same configuration.

  As described above, the rod lens 54 having one end portion facing the front side in the drawing and the rod lens 54 having the other end portion facing the front side in the drawing are regularly arranged.

  In the stacking step in the lens array manufacturing method, the lens material 154 is supplied from the supply device 120 between the pair of side plate materials 114 so that the rod lens 54 is arranged as described above.

  In the third embodiment, the lens material 154 (rod lens 54) having one end portion (the other end portion) facing the front side in the drawing and the lens material having the other end portion (one end portion) facing the front side in the drawing. There exists an effect | action of 1st Embodiment other than the effect | action shown by contacting only 154 (rod lens 54).

<Fourth embodiment>
Next, an example of an optical member, an exposure apparatus, and an image forming apparatus image according to the fourth embodiment of the present invention will be described with reference to FIG. In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected, the description is abbreviate | omitted, and a different part from 1st Embodiment is mainly demonstrated.

  As for one column (the column on the right side in the drawing) of the lens array 230 as an example of the optical member according to the fourth embodiment, the rod lens 54 having one end facing the front side in the drawing and the other end portion in the drawing front. Two rod lenses 54 facing the side are alternately arranged from the lower end in the figure. On the other hand, for the other column (the column on the left side in the figure), the rod lens 54 whose other end part faces the front side in the figure and the rod lens 54 whose one end part faces the front side in the figure are the lower ends in the figure. 2 are alternately arranged.

  As described above, the rod lens 54 having one end portion facing the front side in the drawing and the rod lens 54 having the other end portion facing the front side in the drawing are regularly arranged.

  In the stacking step in the lens array manufacturing method, the lens material 154 is supplied from the supply device 120 between the pair of side plate materials 114 so that the rod lens 54 is arranged as described above.

  In the fourth embodiment, a lens material 154 (rod lens 54) having one end portion (other end portion) facing the front side in the drawing and a lens material having the other end portion (one end portion) facing the front side in the drawing. There exists an effect | action of 1st Embodiment other than the effect | action shown by contacting only 154 (rod lens 54).

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. This will be apparent to those skilled in the art. For example, in the above embodiment, the rod lens 54 is made of glass, but the rod lens 54 may be molded from a resin material.

  Moreover, in the said embodiment, although the end surface radius of the one end part of the optical material direction of the lens material 154 (rod lens 54) was made smaller than the end surface radius of the other end part, the end surface radius of one end part and the end surface of the other end part The radius may be the same.

  In the above embodiment, the lens material 154 is supplied between the pair of side plate materials 114 from above the pair of side plate materials 114 and stacked in the stacking step. However, the lens material 154 is stacked on the pair of side plate materials 114. The lens material 154 may be stacked by supplying between the pair of side plate members 114 from the opened front or rear.

  In the above embodiment, the lens material 154 is divided together with the frame material 122 in the dividing step in a state in which the lens material 154 is fixed inside the frame material 122. However, the side plate material 114 is formed in the same manner as the plate material 104 in advance. Furthermore, the dividing step may be abolished by making the lens material 154 in the same shape as the rod lens 54 in advance.

  In the fourth embodiment, one row (the other row) has one end portion (the other end portion) facing the front side in the drawing, and the other end portion (the one end portion) on the front side in the drawing. The two rod lenses 54 facing toward each other are alternately arranged from the lower end in the drawing, but three or more rod lenses 54 may be alternately arranged.

  In the third and fourth embodiments, the lens arrays 220 and 230 include the closing plate 106. However, as in the second embodiment, the lens arrays 220 and 230 may have a configuration in which both ends are cut away and the closing plate 106 is not provided. .

  In addition, the regular arrangement of the lens material 154 (rod lens 54) whose one end portion faces the front side in the drawing and the lens material 154 (rod lens 54) whose other end portion faces the front side in the drawing in the above embodiment is as follows. As an example, the lens material 154 (rod lens 54) with one end facing the front side in the figure and the lens material 154 (rod lens 54) with the other end facing the front side in the figure are ruled by other arrangements. May be arranged.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 16 Photosensitive drum (an example of an image holding body)
20 Print head (an example of an exposure device)
22 Developer (Example of developing device)
50 Wiring board (an example of a board)
54 Rod lens (an example of a lens)
56 Lens array (an example of an optical member)
58 Case 62 Light-emitting diode array (an example of a light-emitting element)
104 Side plate 114 Side plate material 140 Resin material (an example of resin)
154 Lens material 200 Lens array (an example of an optical member)
220 Lens array (an example of an optical member)
230 Lens array (an example of an optical member)

Claims (4)

A pair of elongate side plates disposed opposite to each other;
A columnar lens arranged in two rows in contact with the side plate between a pair of the side plates;
In the lenses constituting one row, the lenses arranged at least other than both ends are in contact with only one side plate and two adjacent lenses in the other row, and the end surface radius of one end of the lens is: Smaller than the end face radius of the other end,
An optical member in which the lens having one end facing one side and the lens having the other end facing one are regularly arranged . 2. The optical member according to claim 1 , wherein the one row is configured by the lens having the one end portion facing one side, and the other row is configured by the lens having the other end portion facing one side. A substrate on which the light emitting element is mounted;
The optical member according to any one of claims 1 and 2 , further comprising a lens through which light emitted from the light emitting element is transmitted.
A housing for holding the substrate and the optical member;
An exposure apparatus comprising: An image carrier,
The exposure apparatus according to claim 3 , wherein the image carrier is exposed to form an electrostatic latent image;
A developing device for developing the electrostatic latent image formed by the exposure device;
An image forming apparatus comprising: