JP2018171768A - Optical writing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical writing device that enables attitude maintenance of a rod lens array without an increase in the number of components.SOLUTION: In an optical writing device, protrusions 11, 13, 15 are formed in both ends and a center in a Y-axis direction of side walls 61, 63 of a holder 4. The side walls 61 is bent toward an outside surface of a condensation device array (rod lens array) 3 to an extent that the protrusions 11, 13, 15 abut on the outside surface of the rod lens array 3. An abutment part between the protrusions 11, 13, 15 and the rod lens array 3 is fixed by adhesion parts 11a, 13a, 15a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an optical writing apparatus that performs optical writing on a photoconductor, and more particularly to an improvement of a holder for maintaining and fixing a posture of a light condensing element.

  In recent years, in the technical field of optical writing devices, the development of OLED-PH (OLED Print Head) has been highlighted as a new technical trend. OLED-PH uses an organic LED (OLED: Organic Light-Emitting Diode) as a light source and a rod lens array as a condensing element that forms an image on the photosensitive surface of the photosensitive drum. It has the advantages of low power consumption and a small occupied space in the image forming apparatus.

  In the OLED-PH, the rod lens array is sandwiched between two plate holders, and is fixed to a highly rigid plate member together with an array of a plurality of organic LEDs. However, it is difficult to improve the surface machining accuracy of the inner wall surface of the insertion hole of the frame plate holder. When the rod lens array is fixed to the holder and the optical writing is performed by condensing the rod lens array while the processing accuracy of the inner wall surface is not sufficient, the deterioration of the print quality becomes noticeable in the tandem type image forming apparatus. To do. In tandem image forming apparatuses, there are many optical writing devices for each reproduction color such as yellow, magenta, cyan, and black, and if the optical axis for optical writing for each reproduction color is shifted, the photoconductor This is because the image forming positions on the drum are not aligned, causing a color shift of the toner image.

  In order to compensate for the insufficient accuracy of surface processing, Patent Document 1 discloses a support structure for a rod lens array that stabilizes the posture of the rod lens array by tightening screws. FIG. 12 shows a conventional support structure of a rod lens array by screw tightening. The holder 34 in FIG. 12 accommodates the rod lens array 50 in the insertion hole 32 between the pair of wall surfaces 31a and 31b. Screw holes 39a, 40a, and 41a are formed in one of the pair of wall surfaces (wall surface 31a) at three locations in the optical axis direction (Z-axis direction in the drawing). Screw holes 39b, 40b, and 41b are also formed in the other wall surface (wall surface 31b) at three locations in the optical axis direction. When a set screw (screw with a tapered tip and a hexagonal hole formed at the tail end) is screwed into these three screw holes, the tip of the set screw protruding from each screw hole toward the rod lens array side is , Abuts against the side surface of the rod lens array 50 (protected by the contact tool 36). The holder 34 of Patent Document 1 stabilizes the posture of the rod lens array 50 by such support by contact at a plurality of locations.

JP 2002-160401 A

  The support mechanism of the rod lens array disclosed in Patent Document 1 is a stable posture maintenance that is not constrained by insufficient accuracy of surface processing of the wall surface by support by set screws protruding from three screw holes in the optical axis direction of the wall surface Is possible. However, the support mechanism shown in the figure is only one of a plurality of support mechanisms provided in the longitudinal direction of the lens (X-axis direction in the figure). It is necessary to attach a similar support mechanism to a plurality of locations (both ends and the center in the longitudinal direction). Even if the support mechanism is installed at only three locations in the longitudinal direction on both ends and the center of the wall surface, 18 set screws (= 3 × 3 × 2) are required. In addition to this, since it is essential to install a patch for protecting the side surface of the rod lens array, the support mechanism for the rod lens array disclosed in Patent Document 1 has a problem that the number of parts is large.

  An object of the present invention is to provide an optical writing device capable of maintaining the posture of a light collecting element without increasing the number of components.

An optical writing device capable of solving the above-described problem is an optical writing device that performs optical writing on a photosensitive member by light emitted from a plurality of light emitting elements arranged in a line, and the light emitted from the plurality of light emitting elements. A condensing element array supported by a holder is arranged on the optical path of
The condensing element array is configured by arranging a plurality of condensing elements in the same direction as the arrangement direction of the light emitting elements, and the holder has a side wall portion facing an outer surface of the condensing element array. The side wall portion has flexibility to bend in the direction approaching or moving away from the outer surface of the light condensing element array, and among the side wall portions in the holder, both ends in the arrangement direction are provided. A pair of first and second protrusions are formed, and a third protrusion is formed between the first and second protrusions at different height positions in the optical axis direction of the light-collecting element array. The side wall portion is bent to such an extent that the first, second, and third protrusions are in contact with the outer surface of the condensing element array, and the holder and the condensing element array are the first, It is fixed at the contact point between the second and third protrusions and the condensing element array. It is characterized.

  Here, it is desirable to fix the light emitting element and the holder as follows. That is, the array of light emitting elements is mounted on a substrate, the substrate on which the array of light emitting elements is mounted is supported by a plate-like member, and the side wall portion of the holder is the center in the array direction of the light collecting elements. It is desirable to fix to the same plate-like member as the board | substrate which mounted the arrangement | sequence of the said light emitting element in the state which the part bent.

Further, it is desirable that the first to third protrusions have a predetermined positional relationship. That is, the first and second protrusions may have a positional relationship such that the first protrusion and the second protrusion are positioned closer to the plurality of light emitting elements in the optical axis direction than the third protrusion.
In addition to the first to third protrusions, a fourth protrusion may be provided. Specifically, the third protrusion is formed at a central portion of the side wall portion of the holder in the arrangement direction of the light collecting elements, and the third protrusion and the first or second protrusion A fourth protrusion may be formed between the first protrusion and the fourth protrusion, and the fourth protrusion may be disposed on a straight line connecting the third protrusion and the first or second protrusion.

The holder may be a frame. Further, the frame that is the holder has an insertion hole formed in a shape surrounding the outline of the light collecting element array in a plan view, and the side wall portion constitutes an inner wall surface in the longitudinal direction of the insertion hole. May be.
The insertion hole of the holder is wider at both ends in the longitudinal direction than the center side, and the wide portions at both ends in the longitudinal direction are present at both ends of the light condensing element array, and the center side in the longitudinal direction. The narrow portion may be present on the center side of the light condensing element array.

  On the wall surface of the holder of the optical writing device according to the present invention, first to third protrusions are formed at both ends and the center. The wall surface provided with the protrusion is bent, and the first, second, and third protrusions formed at both ends and the center are brought into contact with each other, whereby the first and second formed at both ends and the center. The three-point support using the third protrusions makes it possible to maintain the attitude of the light condensing element array. Without using a set screw or a tool for protecting the side surface of the rod lens array, it is possible to maintain the attitude of the condensing element array with three-point support, so the surface processing accuracy of the holder wall surface is reduced while reducing the number of parts. It is possible to avoid the occurrence of optical axis misalignment due to lack of.

1 is a diagram illustrating a main configuration of an image forming apparatus according to a first embodiment. 1 is a perspective view of an optical writing device 100. FIG. It is a disassembled perspective view of an optical writing device. FIG. 4A is a plan view of the holder 4. FIG. 4B is a diagram showing a cross-sectional configuration when the holder 4 is cut at a position closer to the end portion in the longitudinal direction (Y-axis direction) (position indicated by the alternate long and short dash line A-A ′). FIG. 4C is a diagram illustrating a cross-sectional configuration in the case of cutting at a position closer to the left side in the short side direction (X-axis direction) in FIG. 4A (a position indicated by a one-dot chain line B-B ′). The instrument used for the attachment operation | work which attaches the holder 4 to the rod lens array 3 is shown. FIGS. 6A and 6B show the rod lens array 3 that is fitted into the holder 4 by the lowering of the elevating member 21 (the state before adjustment), and FIGS. Shows a state in which the rod lens array 3 is sandwiched. 6E and 6F show a state in which the tilt of the rod lens array 3 is adjusted. FIG. 7A shows the holder 4 in which the distance between the protrusions 11 to 16 is shorter than the lateral width (width in the X-axis direction) of the rod lens array 3. FIG.7 (b) shows the aspect which inserted the rod lens array 3 in the holder 4 of Fig.7 (a). FIG. 7 (c) shows the suppression of the side walls 61 and 62 using the pressing members 22 and 23. (A)-(c) shows the support of the rod lens array 3 by the holder 4 of the modification 1. FIG. (A)-(c) shows the support of the rod lens array 3 by the holder 4 of the modification 2. FIG. (A)-(c) shows the support of the rod lens array 3 by the holder 4 of the modification 3. FIG. (A)-(c) shows the support of the rod lens array 3 by the holder 4 of the modification 4. FIG. The support structure of the rod lens array by the fastening of the conventional screw is shown.

[1] First Embodiment A first embodiment of the present invention will be described.
(1) Configuration of Image Forming Apparatus First, the configuration of the image forming apparatus according to the present embodiment will be described.
FIG. 1 is a diagram illustrating a main configuration of the image forming apparatus according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1000 is a tandem type color printer apparatus, and includes image forming units 101Y to 101K for each reproduction color, an intermediate transfer belt 102, a secondary transfer roller pair 103, and a supply roller. The paper unit 104, the fixing unit 105, and the discharge tray 106 are included.

  The optical writing device (optical writing device 100) according to the embodiment of the present invention is incorporated in the image forming apparatus 1000 as a component of the image forming units 101Y to 101K. The image forming units 101Y to 101K have a common configuration (configuration shown in a broken line frame of the image forming unit 101Y), although corresponding reproduction colors are different. Specifically, each of the image forming units 101Y to 101K includes an optical writing device 100, a photosensitive drum 110, a charging device 111, a developing device 112, and a primary transfer roller 113.

The charging device 111 uniformly charges the photosensitive surface of the photosensitive drum 110Y. After the charging is started, the optical writing device 100 exposes the photosensitive surface of the photosensitive drum 110 to form an electrostatic latent image.
The developing device 112 supplies toner of a corresponding reproduction color, develops (develops) the electrostatic latent image, and forms a toner image of the corresponding reproduction color.

The primary transfer roller 113 electrostatically transfers (primary transfer) the toner image carried on the photosensitive surface of the photosensitive drum 110 onto the intermediate transfer belt 102.
When forming a monochrome toner image, only the image forming unit 101K corresponding to the K color forms a monochrome toner image of a designated color. When forming a color toner image, the image forming units 101Y to 101C perform the same operation to form toner images of each color of YMCK, and primary transfer onto the intermediate transfer belt 102 so that the toner images of each color of YMCK overlap each other. I do.

After the toner image is transferred through the above process, the intermediate transfer belt 102 rotates in the A direction. As a result, the toner image transferred to the intermediate transfer belt 102 reaches the secondary transfer roller pair 103.
When the toner image primarily transferred to the intermediate transfer belt 102 reaches the secondary transfer roller pair 103, the recording sheet S accumulated in the paper feeding unit 104 is transferred to the secondary transfer roller pair 103 at the same timing. Sent out.

  Accordingly, the toner image transferred to the intermediate transfer belt 102 is secondarily transferred to the recording sheet S by the secondary transfer roller pair 103. After the secondary transfer, the recording sheet S is conveyed to the fixing unit 105. The fixing unit 105 melts the toner that forms an image on the recording sheet and fixes the toner on the recording sheet. The recording sheet S on which the toner image is fixed is discharged to the discharge tray 106. Through the above process, printing on the recording sheet S is performed.

(2) Configuration of Optical Writing Device 100 Next, the configuration of the optical writing device 100 will be described. FIG. 2 is a perspective view of the optical writing device 100, and FIG. 3 is an exploded perspective view of the optical writing device. In FIG. 2, the Y-axis is the main scanning direction, the X-axis is the sub-scanning direction, and the Z-axis is the emission direction of the emitted light from the light source. As shown in the exploded perspective view of FIG. 3, the optical writing device 100 includes an OLED-TFT substrate 1, a sheet metal 2, a rod lens array 3, and a holder 4.

  As shown in FIG. 3, the OLED-TFT substrate 1 has a plurality of OLED elements 1a, b, c, d,... Arranged along the main scanning direction (Y-axis direction) to drive the OLED elements. It is configured by integrating with the TFT circuit. The emitted light from the plurality of OLED elements 1a, b, c, d... In FIG. As shown in FIG. 2, the photosensitive surface 110su of the photosensitive drum 110 exists on the extension line et1 in the traveling direction of the emitted light. As the photosensitive drum 110 rotates in the B direction, the plurality of OLED elements 1a, b, c, d... Arranged in the main scanning direction (Y-axis direction) emit light, thereby electrostatically A latent image is formed on the photosensitive surface 110su of the photosensitive drum 110.

  The sheet metal 2 is a plate-like member made of a highly rigid metal material, and the OLED-TFT substrate 1 is disposed on the surface thereof, and the holder 4 is placed so as to surround the OLED-TFT substrate 1. Since the OLED-TFT substrate 1 is placed on the highly rigid sheet metal 2, the emitted light emitted from the light emitting elements (OLED elements) of the OLED-TFT substrate 1 is a plane formed by the main scanning direction and the sub-scanning direction. It proceeds in the normal direction (Z-axis direction) of (X-Y plane).

  The rod lens array 3 as an example of a condensing element array is configured by bundling a plurality of rod lenses 3a, b, c, d... Along the main scanning direction (Y-axis direction). When the light is collected by the rod lens array 3, an image point formed by the rod lens array 3 exists on an extension line in the optical axis direction ax1 in FIG. In order to form an electrostatic latent image without defocusing, the holder 4 is used so that the optical axis direction ax1 coincides with the emission direction (Z-axis direction) of the emitted light emitted from the light emitting element. The posture of the rod lens array 3 is corrected. Thus, by making the optical axis direction coincide with the emission direction of the emitted light, the emission surface sf3 of the rod lens array 3 in FIG. 3 faces the photosensitive surface 110su of the photosensitive drum 110, and the incident surface sf4 of the rod lens array 3 becomes Opposite to the OLED-TFT substrate 1.

  The holder 4 is a frame formed of a thermoplastic synthetic resin such as a liquid crystal polymer, and has an insertion hole 6 for fitting the rod lens array 3 in the center of the upper surface sf1 thereof. As shown in FIG. 3, the insertion hole 6 penetrates from the upper surface sf1 to the lower surface sf2 of the frame body. The rod lens array 3 is fitted on the upper side of the insertion hole 6, and the OLED is formed on the lower side of the insertion hole 6. -By covering the TFT substrate 1, the rod lens array 3 fitted in the insertion hole can be opposed to the OLED-TFT substrate 1.

(3) Details of Holder 4 Hereinafter, a detailed configuration of the holder 4 will be described. FIG. 4A is a plan view of the holder 4. FIG. 4B is a diagram showing a cross-sectional configuration when the holder 4 is cut at a position near the end in the longitudinal direction (Y-axis direction) in FIG. 4A (the position of the dashed line AA ′). is there. FIG. 4C shows an arrow when cut from the left side of the short side direction (X-axis direction) in FIG. 4A (the position of the alternate long and short dash line BB ′) and viewed from the direction of the arrow. FIG.

  As shown in FIG. 4A, the size of the insertion hole 6 in plan view is larger than that of the rod lens array 3, and the four side walls 61, 62, 63, 64 of the insertion hole 6 are formed on the rod lens array 3. It is formed so as to surround the outline in plan view. The side walls 63 and 64 extending in the short direction (X-axis direction) are thick (see W2 in FIG. 4A), whereas the side walls 61 and 62 extending in the longitudinal direction (Y-axis direction). Is thin (see W1 in FIG. 4A). Since the rigidity of the side walls 61 and 62 is low due to the difference in thickness, the holder 4 has flexibility to bend only in the short side direction (X-axis direction). Since the holder 4 has the flexibility to bend in such a determined direction, the side walls 61 and 62 are bent toward the inside of the holder 4 in FIG. The gap between the outer side surfaces sf5 and sf6 and the side walls 61 and 62 is narrowed.

(4) Details of the projections 11 to 16 Next, the projections 11, 12, 13, 14, 15, and 16 formed on the inner surfaces of the side walls 61 and 62 will be described. As shown in FIG. 4A, a pair of protrusions 11 and 13 are formed on the inner side surfaces of both ends of the side wall 61 in the Y-axis direction. Similar protrusions are also present on the inner surfaces of both ends in the Y-axis direction of the other side wall 62 (see protrusions 12 and 14).

Protrusions 15 and 16 are also formed in the central part where the gap between the side walls 61 and 62 and the rod lens array 3 is the narrowest due to the bending of the side walls 61 and 62.
Hereinafter, the protrusion amount and height position of the protrusions 11 to 16 will be described. 4A and 4B, the lengths of the protrusions 11, 13, and 15 in the positive direction of the X axis with respect to the side wall 61 are the protrusion lengths of the protrusions 11, 13, and 15. Similarly, in FIGS. 4A and 4B, the lengths of the protrusions 12, 14, and 16 in the negative X-axis direction with the side wall 62 as a reference are the protrusion lengths of the protrusions 12, 14, and 16. Comparing these protrusion lengths, it can be seen that the protrusion lengths of the protrusions 11, 12, 13 and 14 are slightly larger than the protrusion lengths of the protrusions 15 and 16. In FIG. 4, the difference in protrusion length is exaggerated, but the actual difference in protrusion length is about 0.1 mm. 4B and 4C, the height positions of the protrusions 11 to 16 are expressed with reference to the position where the OLED-TFT substrate 1 is installed in the Z-axis direction (optical axis direction). Shall. Thus, when the position of the OLED-TFT substrate 1 is used as a reference, as shown in FIGS. 4B and 4C, each of the protrusions 11, 12, 13, and 14 is a protrusion 15 in the Z-axis direction. , 16 is located at a position lower than 16. The holder 4 is manufactured by injection molding so that the protrusions 11 to 16 have the protrusion amount and the height position as described above.

  When the side walls 61 and 62 on which the protrusions 11 to 16 are formed are bent toward the inside, the protrusions 11, 12, 13, and 14 disposed at low positions on both ends in the Y-axis direction are rod lens arrays. 3 side surfaces sf5 and sf6. On the other hand, since the protrusions 15 and 16 are located at the central portions of the thin side walls 61 and 62, the amount of displacement in the X-axis direction due to the warp bending of the wall portions is large, and the protrusions 15 and 16 are outside the both sides of the rod lens array 3. It contacts the side surfaces sf5 and sf6. Therefore, the outer surfaces sf5 and sf6 of the rod lens array 3 are supported from both sides in the lateral direction at low positions in the optical axis direction by the protrusions 11, 12, 13, and 14 at both ends in the longitudinal direction (Y-axis direction). The projections 15 and 16 are supported from both sides in the short direction at a high position in the optical axis direction. Thereby, the rod lens array 3 is provided for three-point support by the protrusions 11 to 16 on both side surfaces sf5 and sf6. After performing an operation of matching the optical axis direction of the rod lens array 3 with the emission direction of the OLED-TFT substrate 1 (details of the operation will be described later), the rod lens array 3 is moved by three projections 11 to 16. By using the point support, the posture of the rod lens array 3 can be stabilized.

  It should be noted that the side walls 61 and 62 are warped by bending the center in the longitudinal direction (Y-axis direction) of the side walls 61 and 62, and the lower portions of the side walls 61 and 62 are fixed to the sheet metal 2. There is a method of bending the upper part of 62 inward. However, warping of the upper portions of the side walls 61 and 62 is undesirable because a reaction force acts on the upper portions of the side walls 61 and 62. That is, when the upper portions of the side walls 61 and 62 are bent inward, the reaction force acts on the upper portions of the side walls 61 and 62. Due to this reaction force, the rod lens array 3 is caught by the protrusions 11 to 16 with time. On the other hand, when the side walls 61 and 62 are bent at the center in the longitudinal direction, no reaction force is generated on the upper portions of the side walls 61 and 62, and the state in which the rod lens array 3 is sandwiched between the protrusions 11 to 16 can be maintained for a long time. it can. In view of the presence or absence of such a reaction force, in this embodiment, the posture of the rod lens array 3 is maintained by bending the center in the longitudinal direction of the side walls 61 and 62.

(5) Details of Bonding Portion Next, the bonding portion for fixing the rod lens array 3 to the holder 4 will be described. As shown in the plan view of FIG. 4A, there are six adhesion portions (adhesion portions 11a, 12a, 13a, 14a, 15a, 16a) between the holder 4 and the rod lens array 3. . These adhesive portions are obtained by applying an adhesive to the contact portions between the protrusions and the rod lens array 3 and drying them. The adhesive portions 11a to 16a are formed so as to cover the protrusions 11 to 16 by applying an adhesive to these contact portions.

  Further, as shown in FIG. 4A, there are also six adhesion portions (adhesion portions 11b, 12b, 13b, 14b, 15b, 16b) between the holder 4 and the sheet metal 2. These adhesion portions are contact points between the holder 4 and the sheet metal, and are located at positions (P1, 2, 3, 4, 5, 6 in the figure) where the coordinates on the Y axis are the same as the protrusions. The adhesive portions 11b, 12b, 13b, 14b, 15b, and 16b are formed by applying an adhesive to these positions P1, 2, 3, 4, 6, and 6 and drying them.

(6) Attachment process of rod lens array 3 Hereinafter, the attachment process of attaching the rod lens array 3 to the holder 4 will be described. In the following description, it is assumed that the attachment of the OLED-TFT substrate 1 to the sheet metal 2 is completed, and the sheet metal 2 on which the OLED-TFT substrate 1 is placed is supplied as a work target by a conveyor or the like. FIG. 5 shows the jig 20 used for the attachment. The rod lens array 3 is attached to the holder 4 by a jig 20 having an elevating member 21, presser members 22, 33, and a light receiving element 24 as shown in FIG.

When the sheet metal 2 on which the OLED-TFT substrate 1 is placed is supplied by a conveyor or the like, the elevating member 21 starts to descend.
The elevating member 21 holds the rod lens array 34 with the arm portion at the tip.
The pair of pressing members 22, 23 hold the holder 4 by sandwiching the wall surface of the holder 4 from both sides, and place the holder 4 below the rod lens array 3. After the holder 4 is arranged in this way, the elevating member 21 starts to descend, and the rod lens array 3 is brought close to the OLED-TFT substrate 1. Above the OLED-TFT substrate 1, the rod lens array 3 approaches the predetermined height position (position indicated by the broken rod lens array 3 ′), so that the rod lens array 3 is inserted into the insertion hole 6 of the holder 4. It is inserted into the inside from above. As described above, in the state where the rod lens array 3 is fitted in the upper portion of the insertion hole, the reverse phase movement and the in-phase movement are performed. The reverse phase movement is an operation of moving the presser member 22 in the X-axis negative direction while moving the presser member 22 in the X-axis positive direction.

In-phase movement is an operation of moving the presser member 22 and the presser member 23 in the same direction (X-axis positive direction or X-axis negative direction).
The light receiving element 24 is attached to the arm portion of the elevating member 21 and receives emitted light that passes through the rod lens array 3 fitted in the holder 4. The light receiving element 24 performs the in-phase movement and the reverse phase movement, and then adjusts the inclination of the rod lens array 3 so that the optical axis direction of the rod lens array 3 coincides with the emission direction of the OLED-TFT substrate 1. It is used to check whether or not

Hereinafter, the attaching operation of the holder 4 using the pressing members 22 and 23 will be described.
FIGS. 6A and 6B show the rod lens array 3 fitted in the holder 4 (state before adjustment) by the lowering of the elevating member 21, and the rod lens array 3 is sandwiched by the projections 11-16. The states are shown in FIGS. 6 (c) and 6 (d). FIGS. 6E and 6F show the state in which the tilt of the rod lens array 3 is adjusted. 6A, 6C, and 6E are plan views of the holder 4, and FIGS. 6B, 6D, and 6F show the holder 4 in the Y-axis direction. It is sectional drawing at the time of cut | disconnecting in the position of the dashed-dotted line AA 'at the edge part side.

In FIG. 6B, the rod lens array 3 is fitted in the holder 4, but a mismatch Δθ is generated between the optical axis direction ax1 of the rod lens array 3 and the emission direction (Z-axis direction). Indicates the situation. FIG. 6B is a schematic diagram, and the inclination of the rod lens array 3 is exaggerated in order to make it easy to understand the occurrence of mismatch in the optical axis direction.
This inclination is corrected in the subsequent steps. First, the pair of presser members 22 and 23 are moved in reverse phase, and the presser members 22 and 23 are moved toward the center of the holder 4. Here, as shown in FIG. 6A, the coordinates of the protrusion 15 on the XY plane are (p, q), and the coordinates of the protrusion 16 on the XY plane are (r, q). In this case, as shown by the arrow di1 in FIG. 6B, the presser member 22 is moved to the right side, and the presser member 23 is moved to the left side as shown by the arrow di2, so that the side walls 61 and 62 are directed toward the center. Bend the sledge. As the warping bends, first, the projections 11 and 12 on both ends and the projections 13 and 14 contact the outer surfaces sf5 and sf6 of the rod lens array 3, and then the projections 15 and 16 on the center side become the rod lens. The movement of the pressing members 22 and 23 is stopped when the outer surfaces sf5 and sf6 of the array 3 are hit.

After all of the protrusions 11 to 16 are in contact with the outer surfaces sf5 and sf6 of the rod lens array 3, the OLED-TFT substrate 1 performs light emission of the OLED and light reception by the light receiving element 24. It is determined whether a correct light emission pattern has been received.
When the light receiving element 24 cannot receive a correct light emission pattern, the in-phase movement is performed assuming that there is a difference between the optical axis direction of the rod lens array 3 and the emission direction of the OLED-TFT substrate 1. For example, it is assumed that the displacement of the rod lens array 3 in the optical axis direction is as shown in FIG. 6B and that the displacement cannot be eliminated even after the holder 4 is sandwiched. In this case, the protrusions 15 and 16 formed at the upper part of the central portion in the longitudinal direction of the side walls 61 and 62 are brought into contact with the outer surfaces sf5 and sf6 of the rod lens array 3, and the arrows di3 and di4 in FIG. As shown, the pressing members 22 and 23 are moved in the positive direction of the X axis. The movement of the pressing members 22 and 23 causes the protrusions 15 and 16 to move in the positive direction of the X axis while the protrusions 11 to 14 are stationary in the X axis direction. Accordingly, the coordinates of the protrusions 15 and 16 are shifted in the positive direction of the X axis by a minute amount Δx, and become (p + h + Δx, q), (p−h + Δx, q).

  When the holding members 22 and 23 are moved, the protrusions 15 and 16 press the outer wall surface of the rod lens array 3. In addition, since the protrusions 11 to 14 are present on the lower side near the light emitting element at the longitudinal ends of the side walls 61 and 62, the protrusions 11 to 14 move the rod lens array 3 when the pressing members 22 and 23 are moved. Plays a supporting role from below. As described above, the contact point with the projections 11 to 14 serves as a fulcrum and the contact point with the projections 15 and 16 serves as a force point. Therefore, by moving the pressing members 22 and 23 in the directions di3 and di4, FIG. As shown in f), a force for rotating the rod lens array 3 acts in the clockwise direction tu1 around the rotation axis rt1. By such a force acting, the outer surfaces sf5 and sf6 of the rod lens array 3 are inclined by a minute angle Δφ corresponding to the minute amount Δx. Due to the inclination of the small angle Δφ, the positional deviation between the incident surface sf3 and the exit surface sf4 of the rod lens array 3 is reduced.

After such movement of Δx, light emission of the OLED on the OLED-TFT substrate 1 and light reception by the light receiving element 24 are executed, and it is determined whether or not the light receiving element 24 has received a correct light emission pattern. Thereafter, the in-phase movement of the minute amount Δx is repeated until a correct light receiving pattern is obtained by the light receiving element 24.
In addition, when the above-mentioned minute amount movement causes the deviation between the incident surface and the emission surface of the rod lens array 3 to increase and the light reception deviation becomes conspicuous, the moving direction of the in-phase movement is reversed. Specifically, the amount of displacement in the X-axis direction is set to “−Δx”, and the rod lens array 3 is tilted counterclockwise tu2 in FIG. . It is assumed that the positional relationship between the incident surface on the lower end side of the rod lens array 3 and the exit surface on the upper end side is eliminated by repeating the minute amount change of the protrusions 15 and 16 several times. If it does so, the incident position to the rod lens array 3 of the emitted light emitted from the OLED-TFT substrate 1 will become stable, and the light receiving element 24 will observe the correct light emission pattern. When a correct light emission pattern is observed in the light receiving element 24, the mismatch between the optical axis direction of the rod lens array 3 and the emission direction of the OLED-TFT substrate 1 is resolved, and the bending of the side walls 61 and 62 is finished.

In this way, the contact point between the rod lens array 3 and the protrusions 11 to 16 and the side walls 61 and 62 of the holder and the contact point P1 between the sheet metal 2 in the state in which the optical axis direction coincides with the emission direction. The rod lens array 3 and the holder 4 are fixed to the sheet metal 2 by applying an adhesive to P6 (contact points having the same Y coordinate) and drying.
(7) Supplement In the first embodiment, as shown in FIG. In the natural shape before the side walls 61 and 62 of the holder 4 are bent, the spacing between the projections 11 and 12 provided on the side walls 61 and 62, the spacing between the projections 13 and 14, and the spacing between the projections 15 and 16 are as follows. However, although it set as the structure set wider than the horizontal width of the rod lens array 3, the following structures can also be taken. Specifically, as shown in FIG. 7A, the protrusions 11 to 16 have the same or substantially the same protrusion length, and the protrusions 11 and 12 are in a state before the side walls 61 and 62 are bent. The inter-projection spacing span1, the inter-projection spacing span2 between the projections 13 and the projection 14, and the inter-projection spacing span3 between the projections 15 and 16 are all greater than the lateral width (width in the X-axis direction) of the rod lens array 3. It can be set as the structure shortened. The above “substantially the same” means that even if the design is the same length, the projection length of the projections 11 to 16 is very small due to variations in the tolerance range in the projection length of the projections 11 to 16. A difference exists.

Since the inter-protrusion spacing spans 1, 2, and 3 are shorter than the lateral width of the rod lens array 3, when the rod lens array 3 is inserted into the holder 4 by the lowering by the elevating member 21 in the mounting process of the holder 4, The distance between the protrusions is increased.
At this time, the rod lens array 3 is in the form shown in FIG. 7B. In the holder 4, the central portion of the side wall 61 extends in the negative direction of the X axis, and the central portion of the side wall 62 is in the positive direction of the X axis. And the rod lens array 3 is sandwiched. In this case, the protrusions 11, 12, 13, and 14 formed at both ends of the side walls 61 and 62 are in contact with the outer peripheral surface of the rod lens array 3, but the protrusion 15 and the protrusion formed at the center of the side walls 61 and 62 Since the distance from 16 is greatly expanded, the protrusions 15 and 16 float from the rod lens array 3. In this state, as shown in FIG. 7 (c), the holding members 22 and 23 are moved in reverse phase, and the side walls 61 and 62 are pressed as indicated by arrows di1 and di2, and the central portion in the Y-axis direction. The protrusions 15 and 16 are brought into contact with the outer peripheral surface of the rod lens array 3. Thereby, three-point support by the protrusions 11, 13, and 15 and three-point support by the protrusions 12, 14, and 16 are possible. In this way, the light emitting element of the OLED-TFT substrate 1 emits light in a state where the protrusions 15 and 16 are in contact with the outer surface of the rod lens array 3, and it is determined whether or not a correct light receiving pattern can be obtained. When the correct light receiving pattern is not obtained, the minute movement of the rod lens array 3 is repeated by causing the holding members 22 and 23 to move in phase as shown in FIG. Correct posture. In this case, since the distance between the protrusions is shorter than the lateral width of the rod lens array 3, the outer surface of the rod lens array 3 is pressed by the protrusions 11 to 16 from both sides. The posture can be stabilized.

(8) Summary According to the present embodiment as described above, the rod lens array is formed by pushing or deflecting the side walls 61 and 62 of the holder 4 so that the light collection rate of the light emitted through the rod lens array 3 is maximized. The optical axis direction of 3 can coincide with the emission direction of the light emitting element. Various parts for constructing the support structure of the rod lens array of Patent Document 1 (parts such as a fitting for protecting the side surface of the rod lens array 3 and a set screw for maintaining the posture of the rod lens array 3) are unnecessary. Therefore, the number of parts can be greatly reduced.

Further, since the screwing operation of the set screw is not required for mounting the rod lens array, the mounting operation of the holder 4 can be greatly simplified.
Further, the posture of the rod lens array 3 according to the present embodiment is maintained by sandwiching the projections 11-16. Since wear of the side wall due to screwing of a set screw or the like cannot occur, it is not necessary to use a metal material having high strength for forming the side wall of the holder 3. Since the holder 3 can be molded from a low-strength synthetic resin, the cost of the optical writing device can be reduced.

(Modification 1)
In the first embodiment, a protrusion for supporting three points is provided on each of the wall surfaces 61 and 61 of the insertion hole 6 of the rod lens array 3, and the rod lens array 34 is sandwiched between the protrusions. On the other hand, the modification 1 discloses the one-side support by the one side wall of the holder 4. 8A to 8C show support of the rod lens array 3 by the holder 4 of the first modification. 8A to 8C, the same trihedral views as those in FIGS. 4A to 4C (a plan view of the holder 4 and the one-dot chain line AA of the holder 4 in the Y-axis direction end side. The form of the holder 4 according to the modified example 1 is represented by using a cross-sectional view taken at the position of “′ and a cross-sectional view taken at the position of the one-dot chain line BB ′ in the X-axis direction”. In addition, also in the following modified examples (modified examples 2 to 4 described later), the form of the holder 4 according to the modified example is represented using the same three-view drawing.

  In order to support the one side, in the first modification, as shown in FIGS. 8A to 8C, the protrusions 11, 13, and 15 are provided only on one side wall 61 of the holder 4. The protrusions 11 and 13 provided at both ends of one side wall 61 and the protrusion 15 provided at the center are different from each other in the height position in the optical axis direction, as shown in FIG. It is the same as an example of a)-(c). In this way, by adopting a configuration in which only one of the outer surfaces sf5 and sf6 of the rod lens array 3 is supported by a single plate-shaped holder 4, the holder 4 is made to be a frame-shaped holder. The material used for forming can be reduced, and the cost of the optical writing apparatus 100 can be further reduced accordingly.

(Modification 2)
In 1st Embodiment, although the protrusions 11-16 were provided in the both ends and center part of the longitudinal direction (Y-axis direction) of the side walls 61 and 62, the modification 2 improves the protrusion other than the protrusions 11-16 on a wall surface. About. 9A to 9C show the support of the rod lens array 3 by the holder 4 of the second modification. In FIGS. 9A to 9C, the adhesive is not shown in order to facilitate understanding that the number and height of the protrusions are different from those of the first embodiment. Actually, the protrusions 11 to 20, the rod lens array 3, and the holder 4 are fixed with an adhesive as in the first embodiment. The same applies to the following modifications.

  As shown in FIGS. 9A and 9B, protrusions 17, 18, 19, and 20 are formed on the wall surfaces 61 and 62 of the holder 4 according to Modification 2 as protrusions other than the protrusions 11 to 16. Yes. As shown in FIG. 9C, the protrusion 17 is formed at the midpoint of the straight line VL1 connecting the protrusion 11 at the longitudinal end of the side wall 61 and the central protrusion 15, and the protrusion 19 is the side wall 61. Is formed at the midpoint of a straight line VL2 connecting the protrusion 13 at the other end in the longitudinal direction and the protrusion 15 at the center. The protrusion lengths of the protrusions 17 and 19 are the same or substantially the same, shorter than the protrusions 11 and 13 on both ends in the longitudinal direction, and longer than the protrusions 15 and 16 on the center side. The protrusion lengths of the protrusions 12, 14, 16, 18, and 20 have the same relationship. Further, as shown in FIG. 9A, the side walls 61 and 62 are bent inward, so that the projections 17 and 18 and the projections 19 and 20 are outside the rod lens array 3 as in the projections 11 to 16. It contacts the side surfaces sf5 and sf6.

  In this modification, the outer surfaces sf5 and sf6 of the rod lens array 3 are in contact with not only the protrusions 11 to 16 but also the protrusions 18 to 20, and thus the protrusions 11 are caused by aging of the holder 4 and vibration of the image forming apparatus. Even if contact with any one of -20 becomes impossible, if the three-point support by the remaining projections is made by the outer surfaces sf5 and sf6 of the rod lens array 3, the rod lens The attitude of the array 3 can be maintained.

  Further, the protrusions 11 to 20 are present on the virtual straight lines VL1 and VL2 on the inner wall surfaces of the side walls 61 and 62, and the protrusion lengths of the protrusions 17 and 19 are set as described above. Even when 11 to 20 cannot be contacted by some of the protrusions and the three-point support is continued with the remaining protrusions, the posture of the rod lens array 3 does not change greatly. By doing so, in this modification, the consistency of the positional relationship between the incident surface and the exit surface of the rod lens array 3 can be maintained over a long period of time.

(Modification 3)
In the first embodiment, the insertion hole 6 has a rectangular shape. On the other hand, the modified example 3 relates to an improvement in which a wide portion and a narrow portion are provided in the longitudinal direction (Y-axis direction). 10A to 10C show the support of the rod lens array 3 by the holder 4 of the third modification.
10A to 10C, the insertion holes in the holder 4 have wide portions 82 and 83 at both ends in the longitudinal direction, and the narrow portion 81 exists between the wide portions 82 and 83. To do. The protrusions 11, 12, 13, and 14 at the longitudinal ends are present at both ends of the side walls 71 and 72 surrounding the narrow portion 81, and the protrusions 15 and 16 are formed on the side walls 71 and 72 surrounding the narrow portion 81. Present in the center.

  In the holder 4 of Modification 3, the side walls 73, 74, 75, 76 surrounding the wide portions 82, 83 are formed so as to bypass the wide portions 82, 83. , 14 and the distance from the side wall 64 in the short direction to the protrusions 11 and 12 are long. It has a detour shape and a long distance from the protrusions 11 to 16 is secured. Therefore, the side wall of the holder 4 according to the modified example 3 has high flexibility, bends greatly inward or outward, and easily fits the shape of the rod lens array 3. Since the shape of the side wall can be fitted to the rod lens array 3 and the rod lens array 3 can be sandwiched, the holder 4 according to the modified example 3 can further stabilize the posture of the rod lens array 3.

(Modification 4)
In the first embodiment, the protrusions 11, 12, 13, and 14 at both ends in the longitudinal direction for supporting the rod lens array 3 are provided at low positions in the optical axis direction, but the present invention is not limited to this. As shown in FIGS. 11A, 11 </ b> B, and 11 </ b> C, the protrusions 11, 12, 13, and 14 at both ends in the longitudinal direction may be provided at positions higher than the protrusions 15 and 16 in the optical axis direction. . FIGS. 11A, 11 </ b> B, and 11 </ b> C show the holder 4 according to the fourth modification. FIGS. 11A to 11C show the support of the rod lens array 3 by the holder 4 of the fourth modification. As shown in FIG. 11A, the fact that the projections 11 to 14 are present at the longitudinal ends of the side walls 61 and 62 and that the projections 15 and 16 are present at the longitudinal center of the side walls 61 and 62 are the first. This is the same as the embodiment. The difference is the positional relationship in the Z-axis direction. That is, in Modification 4, as shown in FIG. 11B, the protrusions 11 to 14 are formed at high positions in the optical axis direction, and the protrusions 15 to 16 are formed at low positions in the optical axis direction. . Since the protrusions 11 to 14 exist at positions far from the light emitting elements 1 a, b, c, d... At the longitudinal ends of the side walls 61 and 62, the protrusions 11 to 14 correspond to the pressing members 22 and 23. During movement, it plays a role of supporting the outer surfaces sf5 and sf6 of the rod lens array 3 on both upper sides. Since the rod lens array 3 is supported by the protrusions 11 to 14 on the upper side of both longitudinal ends of the side walls 61 and 62, the rod lens array 3 is rotated clockwise tu1 about the rotation axis rt2 as shown in FIG. , Tilts counterclockwise tu2. Since the inclined rotation axis rt2 exists at a high position in the Z-axis direction, in the fourth modification, the lower side in the optical axis direction of the rod lens array 3 can be greatly inclined. Deviation from the emission surface can be eliminated.

(Other variations)
As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the above-described embodiment, and the following modifications can be implemented.
(1) In the above embodiment, the case where the image forming apparatus is a tandem type color printer apparatus has been described as an example. However, it is needless to say that the present invention is not limited to this, and a color printer apparatus other than a tandem type printer The present invention may be applied to a monochrome printer apparatus. The same applies when the present invention is applied to a single-function machine such as a copying machine equipped with a scanner, a facsimile machine equipped with a facsimile communication function, or a multi-function peripheral (MFP) having these functions. An effect can be obtained.

(2) The protrusion amounts of the protrusions 11 to 16 are the amount of bending when the side walls 61 and 62 are bent to the limit in the longitudinal direction and the height position of the protrusions 11 to 16 in the optical axis direction (coordinates in the Z-axis direction). It is desirable to calculate based on the distance between the side walls 61 and 62 and the outer surfaces sf5 and sf6 of the rod lens array 3.
This limit amount of deflection includes the load applied to the side walls 61 and 62, the length of the side walls 61 and 62 in the Z-axis direction, the longitudinal elastic modulus (Young's modulus) of the material constituting the side walls 61 and 62, and the side walls 61 and 62. It is calculated based on the secondary moment of the cross section that is specific to the shape. Thus, when the side walls 61 and 62 are bent to the limit in the longitudinal direction, the protrusions 11 to 16 are displaced in the X-axis direction by an amount corresponding to the Z coordinate. The amount of change of the projections 11 to 16 (hereinafter referred to as the limit amount of change) when the side walls 61 and 62 are bent to the limit is the ratio between the total height of the side walls 61 and 62 and the height of the side walls 61 and 62 in the Z-axis direction. Can be calculated based on Then, by subtracting the limit shift amount of the protrusions 11 to 16 from the distance from the side walls 61 and 62 to the outer surfaces sf5 and sf6 of the rod lens array 3, the desired protrusion amount of the protrusions 11 to 16 can be calculated. .

(3) The protrusions 11 and 13 located at both ends in the longitudinal direction may be formed at different positions in the optical axis direction.
Further, in the configuration in which the protrusions 15 and 16 are longer than the protrusions 11 to 14, the central portion of the side walls 61 and 62 of the holder 4 in the longitudinal direction (the arrangement direction of the light emitting elements 1a, b, c, d...). May be bent in a direction away from the outer surfaces sf5 and sf6 of the rod lens array 3, as well as in a direction approaching the outer surfaces sf5 and sf6 of the rod lens array 3.

Since the protrusions 15 and 16 are longer than the protrusions 11 to 14, the protrusions 15 and 16 are brought into contact with the outer surfaces sf 5 and sf 6 of the rod lens array 3 by bending the side walls 61 and 62 outward. Can do. Thus, by bending the side walls 61 and 62 outward, three-point support by the protrusions 11 to 16 may be performed, and the posture of the rod lens array 3 may be maintained.
(4) In 1st Embodiment, although the side walls 61 and 62 of the holder 4 were directly mounted on the sheet metal 2, it replaced with this, and the stand which provided the base and the leg part on the outer wall surface of the side walls 61 and 62 was replaced. A shaped holder may be used. In this case, the holder having the different shape is placed on the sheet metal 2 so as to straddle the OLED-TFT substrate 1 with the pedestal and legs.

(5) In the first embodiment, the adhesive is used for fixing the rod lens array 3 and the holder 4 and fixing the holder 4 and the sheet metal 2, but the present invention is not limited to this. These may be fixed by welding the holder 4 or soldering.
(6) In the first embodiment, the holder 4 is integrally formed of resin. Not limited to this, the holder 4 may be made of metal or the like. Moreover, although OLED was demonstrated as an example of a light emitting element, it is not restricted to this. Other light emitting elements may be used as long as the light emitting elements can be arranged in a line.

  The optical writing apparatus and the image forming apparatus according to the present invention are useful as an apparatus that can prevent deterioration in the imaging state of light emitted from a light emitting element provided in an OLED-PH or the like.

DESCRIPTION OF SYMBOLS 1 OLED-TFT board 2 Sheet metal 3 Rod lens array 4 Holder 6 Insertion hole 11-16 Protrusion 21 Lifting member 22, 23 Jig 23 Jig 61-64 Side wall 100 Optical writing device 101Y-101K Image forming part 102 Intermediate transfer belt 103 Secondary transfer roller pair 104 Paper feed unit 105 Fixing unit 106 Discharge tray 110 Photosensitive drum 111 Charging device 112 Developing device 113 Primary transfer roller 1000 Image forming apparatus

Claims (6)

An optical writing device that performs optical writing on a photosensitive member by light emitted from a plurality of light emitting elements arranged in a line,
A condensing element array supported by a holder is disposed on an optical path of outgoing light emitted from the plurality of light emitting elements,
The condensing element array is configured by arranging a plurality of condensing elements in the same direction as the arrangement direction of the light emitting elements,
The holder has a side wall portion that opposes the outer surface of the light condensing element array, and the side wall portion is flexible so as to bend toward or away from the outer surface of the light condensing element array. Have
A pair of first and second protrusions are formed at both ends of the side wall portion of the holder in the arrangement direction, and the light of the condensing element array is interposed between the first and second protrusions. Third protrusions are formed at different height positions in the axial direction,
The side wall portion is bent to such an extent that the first, second, and third protrusions are in contact with the outer surface of the condensing element array, and the holder and the condensing element array include the first, second, and second protrusions. An optical writing device, wherein the projection is fixed at a contact portion between the projection 3 and the light condensing element array. The array of light emitting elements is mounted on a substrate, and the substrate on which the array of light emitting elements is mounted is supported by a plate-like member,
The side wall portion of the holder is fixed to the same plate-like member as the substrate on which the array of the light emitting elements is mounted in a state where the central portion in the array direction of the light collecting elements is bent. 1. The optical writing device according to 1. The first to third protrusions have a positional relationship such that the first and second protrusions are positioned closer to the plurality of light emitting elements in the optical axis direction than the third protrusion. The optical writing device according to claim 1 or 2. The third protrusion is formed in a central portion of the holder in the arrangement direction of the condensing element among the side wall portions of the holder, and between the third protrusion and the first or second protrusion, A fourth protrusion is formed;
The light according to any one of claims 1 to 3, wherein the fourth protrusion is disposed on a straight line connecting the third protrusion and the first or second protrusion. Writing device. The holder is a frame, and in a plan view, an insertion hole having a shape surrounding the outline of the light collecting element array is formed,
The optical writing device according to any one of claims 1 to 4, wherein the side wall portion constitutes an inner wall surface in a longitudinal direction of the insertion hole. The insertion hole has both ends in the longitudinal direction wider than the center side, and the wide portions at both ends in the longitudinal direction are present at both ends of the light collecting element array, and the width at the center side in the longitudinal direction. The optical writing apparatus according to claim 5, wherein the narrow portion exists on a center side of the light condensing element array.

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