Print head and image forming apparatus

Abstract

To provide a print head and an image forming apparatus which can effectively prevent the occurrence of inconvenience such as a beam diameter failure on the surface of an image carrier when the surface of the image carrier is irradiated with light emitted by a plurality of light emitting elements.SOLUTION: The print head 3 includes a light emitting element panel 311, a lens array 32, and a fixing member 314. A rib 314b is provided on the surface (back surface 314d) of the fixing member 314 made of a plastic material. The plurality of light emitting elements 31-31 are provided on the light emitting panel 311 so that each of the light emitting points 31a to 31a does not overlap with the rib regions α 1, α 2, or are provided on the surface (rear surface 314b) of the fixing member 314 so that at least two rib 314d intersect with each other. The plurality of light emitting elements 31-31 are provided on the light emitting panel 311 such that none of the light emitting points 31a to 31a overlaps with the intersection area α 3.SELECTED DRAWING: Figure 31

Description

[Technical Field]

[0001] The present disclosure relates to printheads and image forming devices such as copiers, multifunction peripherals, printers, and facsimile machines. [Background technology]

[0002] A print head generally comprises an light-emitting element mounting member having a plurality of light-emitting elements arranged in a line, a lens array that focuses the light emitted by the plurality of light-emitting elements onto an image carrier (e.g., a photosensitive drum), and a fixing member that fixes the light-emitting element mounting member (see, for example, Patent Document 1).

[0003] When the fixing member is made of a resin material, it needs to have a certain degree of strength to prevent deformation. To achieve this, strength is ensured by providing ribs on the surface of the fixing member opposite the light-emitting element mounting member side. However, due to the shape of the ribs, displacements (particularly recesses, so-called rib sink marks) occur at the locations corresponding to the ribs on the surface of the fixing member where the light-emitting element mounting member is provided.

[0004] In this regard, when a rigid light-emitting element substrate (glass substrate) is used as the light-emitting element mounting member, as in the print head (exposure head) described in Patent Document 1, the light-emitting element substrate is less likely to deform on the heat sink (fixing member). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-74455 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a film-like light-emitting element panel is used instead of a rigid light-emitting element substrate, the following inconveniences arise.

[0007] Fig. 38 is a cross-sectional view showing a state in which displacement portions 314e are generated at locations corresponding to ribs 314d on front surface 314a of fixing member 314, which has ribs 314d provided on back surface 314b. Fig. 39 is a cross-sectional view showing a state in which film-like light-emitting element panel 311 is deformed by displacement portions 314e.

[0008] The film-like light-emitting element panel 311 is very thin, for example, about 0.14 mm thick, and is adhered (bonded) to the fixing member 314. Therefore, if a displacement portion 314e (especially a sink mark) occurs at a location corresponding to the rib 314d on the surface (surface 314a) of the fixing member 314 on which the light-emitting element panel 311 is provided due to the rib shape (see Figure 38), the light-emitting element panel 311 will be deformed (for example, become wavy) by the displacement portion 314e (see Figure 39).

[0009] 38, when the light-emitting element panel 311 is deformed by the displacement portion 314e, the positional relationship between the lens array 32 and each of the light-emitting points 31a-31a of the light-emitting elements 31-31 of the plurality of light-emitting elements 31-31 in the portion of the light-emitting element panel 311 that corresponds to the displacement portion 314e is disrupted (the focal length with the lens array 32 is shifted), resulting in portions where the focus is unacceptable at each image height, as shown in FIG. 39. Therefore, problems such as an insufficient beam diameter on the surface of the image carrier occur when light emitted from the plurality of light-emitting elements 31-31 is irradiated onto the surface of the image carrier.

[0010] Therefore, the present disclosure aims to provide a print head and an image forming device that can effectively prevent problems such as poor beam diameter on the surface of an image carrier when light emitted from multiple light-emitting elements is irradiated onto the surface of the image carrier. [Means for solving the problem]

[0011] In order to solve the above-mentioned problems, the present disclosure provides a print head and an image forming apparatus according to the following first and second aspects.

[0012] (1) First embodiment of print head A print head of a first aspect of the present disclosure is a print head comprising a film-shaped light-emitting element panel having a plurality of light-emitting elements arranged in a line, a lens array that focuses light emitted by the plurality of light-emitting elements onto an image carrier, and a fixing member that fixes the light-emitting element panel, wherein the fixing member is made of a resin material, a rib is provided on the surface of the fixing member opposite the light-emitting element panel, and the plurality of light-emitting elements are provided on the light-emitting element panel so that none of their light-emitting points overlaps the rib area corresponding to the rib.

[0013] (2) Second embodiment of print head A print head of a second aspect of the present disclosure is a print head comprising a film-shaped light-emitting element panel having a plurality of light-emitting elements arranged in a line, a lens array that focuses light emitted by the plurality of light-emitting elements onto an image carrier, and a fixing member that fixes the light-emitting element panel, wherein the fixing member is made of a resin material, and at least two ribs are arranged to intersect on the surface of the fixing member opposite the light-emitting element panel, and the plurality of light-emitting elements are arranged on the light-emitting element panel so that none of their light-emitting points overlaps the intersection area corresponding to the intersection where the at least two ribs intersect.

[0014] (3) Image forming device An image forming apparatus according to the present disclosure is characterized by including the print head according to the first or second aspect of the present disclosure. [Effects of the Invention]

[0015] According to the present disclosure, it is possible to effectively prevent problems such as poor beam diameter on the surface of an image carrier when light emitted from multiple light-emitting elements is irradiated onto the surface of the image carrier. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view showing an image forming apparatus according to an embodiment of the present invention. [Figure 2] 1 is a perspective view of an example of a print head provided on a main body frame in an image forming apparatus according to an embodiment of the present invention, viewed obliquely from above on the front side. [Figure 3] 3 is a perspective view of the print head shown in FIG. 2 supported on a mounting section, viewed obliquely from above on the front side. [Figure 4] FIG. 2 is a perspective view of the print head as seen from diagonally above the rear side. [Figure 5] FIG. 5 is a perspective view of the print head shown in FIG. 4, viewed obliquely from below on the front side. [Figure 6] 5 is an exploded perspective view of the print head shown in FIG. 4, viewed obliquely from above on the front side. FIG. [Figure 7] 5 is an exploded perspective view of the print head shown in FIG. 4, viewed obliquely from below on the rear side. FIG. [Figure 8] FIG. 2 is a cross-sectional perspective view of the print head as seen from diagonally above the front side. [Figure 9] FIG. 2 is a cross-sectional view of a print head. [Figure 10] FIG. 10 is a schematic diagram for easily understanding the cross-sectional view shown in FIG. [Figure 11] 1 is a plan view showing a state in which a flexible circuit board is extended linearly in a light-emitting element panel, a flexible circuit board, and a printed wiring board that constitute a print head. FIG. [Figure 12] FIG. 10 is a perspective view illustrating an example of a first step in the manufacturing process of the print head. [Figure 13] FIG. 10 is a perspective view illustrating an example of a second step in the manufacturing process of the print head. [Figure 14] FIG. 10 is a perspective view illustrating an example of a third step in the manufacturing process of the print head. [Figure 15] FIG. 10 is a perspective view illustrating an example of a fourth step in the manufacturing process of the print head. [Figure 16] FIG. 10 is a perspective view illustrating an example of a fifth step in the manufacturing process of the print head. [Figure 17] FIG. 10 is a perspective view illustrating an example of a sixth step in the manufacturing process of the print head. [Figure 18] FIG. 10 is a perspective view showing a state in which a light-emitting element panel is provided on a fixing member. [Figure 19] FIG. [Figure 20] 1 is a perspective view showing a first embodiment of a rib provided on the rear surface of a fixing member. FIG. [Figure 21] FIG. 10 is a perspective view showing a second embodiment of a rib provided on the rear surface of the fixing member. [Figure 22] FIG. 10 is a perspective view showing a rib of a third embodiment provided on the rear surface of the fixing member. [Figure 23] FIG. 10 is a perspective view showing a rib of a fourth embodiment provided on the rear surface of the fixing member. [Figure 24] 21 is a plan view showing the positional relationship between the rib and a plurality of light emitting elements of the first embodiment shown in FIG. 20 in a first comparative example. FIG. [Figure 25] 21 is a bottom view showing the positional relationship between the rib and a plurality of light emitting elements of the first embodiment shown in FIG. 20 in a first comparative example. FIG. [Figure 26] 23 is a plan view showing the positional relationship between the rib and a plurality of light emitting elements in the third embodiment shown in FIG. 22 in a second comparative example. FIG. [Figure 27] 23 is a bottom view showing the positional relationship between the rib and a plurality of light emitting elements in the third embodiment shown in FIG. 22 in a second comparative example. FIG. [Figure 28] 24 is a plan view showing the positional relationship between the rib and a plurality of light emitting elements in the fourth embodiment shown in FIG. 23 in a third comparative example. FIG. [Figure 29] 24 is a bottom view showing the positional relationship between the rib and a plurality of light emitting elements in the fourth embodiment shown in FIG. 23 in a third comparative example. FIG. [Figure 30] 21 is a plan view showing the positional relationship between a rib and a plurality of light emitting elements of the first mode shown in FIG. 20 according to the first embodiment-1. FIG. [Figure 31] 21 is a bottom view showing the positional relationship between the rib and a plurality of light emitting elements of the first mode shown in FIG. 20 according to the first embodiment-1. FIG. [Figure 32] 22 is a plan view showing the positional relationship between the rib and a plurality of light emitting elements of the second aspect shown in FIG. 21 according to the first embodiment-2. FIG. [Figure 33]22 is a bottom view showing the positional relationship between the rib and a plurality of light emitting elements of the second aspect shown in FIG. 21 according to the first embodiment-2. FIG. [Figure 34] 23 is a plan view showing the positional relationship between a rib and a plurality of light emitting elements according to the second embodiment-1, in which the positions of the intersecting portions are shifted to either side in the width direction in the third mode shown in FIG. 22. FIG. [Figure 35] 23 is a bottom view showing the positional relationship between a rib and a plurality of light emitting elements according to the second embodiment-1, in which the positions of the intersecting portions are shifted to either side in the width direction in the third mode shown in FIG. 22. FIG. [Figure 36] 24 is a plan view showing the positional relationship between a rib and a plurality of light emitting elements according to the second embodiment, in which the positions of the intersecting portions are shifted to either side in the width direction in the fourth mode shown in FIG. 23. FIG. [Figure 37] 24 is a bottom view showing the positional relationship between a rib and a plurality of light emitting elements according to the second embodiment, in which the positions of the intersecting portions are shifted to either side in the width direction in the fourth mode shown in FIG. 23. FIG. [Figure 38] 10 is a cross-sectional view showing a state in which a displacement portion occurs at a location on the surface of a fixing member having a rib provided on the back surface thereof, the location corresponding to the rib. FIG. [Figure 39] 10 is a cross-sectional view showing a state in which the film-shaped light-emitting element panel is deformed by a displacement portion. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0018] (Image forming device) 1 is a cross-sectional view showing an image forming apparatus 100 according to this embodiment. In the figure, the rotational axis direction of the photosensitive drum 1 is designated as X, the front side as X1, the back side as X2, the direction perpendicular to the rotational axis direction X as the left-right direction Y, the right side as Y1, the left side as Y2, and the up-down direction perpendicular to the rotational axis direction X and the left-right direction Y as Z, in the following description.

[0019] Image data handled by the image forming apparatus main body 101 of the image forming apparatus 100 corresponds to a color image using each of the colors black (K), cyan (C), magenta (M), and yellow (Y), or a monochrome image using a single color (e.g., black). For this reason, four photosensitive drums 1 (image carriers), chargers 2, print heads 3, developing devices 4, primary transfer devices 5, and drum cleaning devices 6 are provided to form four types of toner images corresponding to each color, and four image stations Pa, Pb, Pc, and Pd are configured, each corresponding to black, cyan, magenta, and yellow. Note that the image forming apparatus 100 may also be a monochrome image forming apparatus.

[0020] In each of the image stations Pa, Pb, Pc, and Pd, the chargers 2-2 uniformly charge the surfaces 1a of the photosensitive drums 1-1, which are driven to rotate in a predetermined rotation direction R, to a predetermined potential. The print heads 3-3 expose the surfaces 1a of the photosensitive drums 1-1 to light, forming electrostatic latent images on the surfaces 1a of the photosensitive drums 1-1. The developing devices 4 develop the electrostatic latent images on the surfaces 1a of the photosensitive drums 1-1 to form toner images on the surfaces 1a of the photosensitive drums 1-1. This results in toner images of each color being formed on the surfaces 1a of the photosensitive drums 1-1. The drum cleaning devices 6-6 remove and collect residual toner from the surfaces 1a of the photosensitive drums 1-1. The primary transfer devices 5-5 sequentially transfer the toner images of each color on the surfaces 1a of the photosensitive drums 1-1, superimposed on one another, to an intermediate transfer belt 23, which is rotated by a drive roller 21 and a driven roller 22 of a belt drive device 20, forming color toner images on the intermediate transfer belt 23. The belt cleaning device 7 removes and collects residual toner from the intermediate transfer belt 23 .

[0021] A transfer nip portion TN is formed between the intermediate transfer belt 23 and a transfer roller 81 of the secondary transfer device 8. The transfer roller 81 of the secondary transfer device 8 sandwiches a sheet P, such as a recording paper, transported through the sheet transport path 11 in the transfer nip portion TN and transports it together with the intermediate transfer belt 23, while transferring the color toner image on the surface of the intermediate transfer belt 23 onto the sheet P. The fixing device 9 fixes the color toner image on the sheet P by sandwiching the sheet P between a fixing member (fixing belt 91 in this example) and a pressure member (pressure roller 92 in this example) and applying heat and pressure to the sheet P.

[0022] The sheet P is drawn out of the paper feed cassette 13 by the pickup roller 12, transported through the sheet transport path 11, passed through the secondary transfer device 8 and the fixing device 9, and then transported to the discharge tray 15 via the discharge roller 14. The sheet transport path 11 is provided with a registration roller 16 and the like. The registration roller 16 temporarily stops the sheet P, aligns the leading edge of the sheet P, and then starts transporting the sheet P in accordance with the timing of the transfer of the toner image at the transfer nip portion TN between the intermediate transfer belt 23 and the transfer roller 81.

[0023] FIG. 2 is a perspective view of an example of print heads 3-3 in an image forming apparatus 100 according to this embodiment, as viewed obliquely from above the front side X1, mounted on a main body frame FL (FL1-FL3). FIG. 3 is a perspective view of the print head 3 shown in FIG. 2 supported by a mounting portion 210, as viewed obliquely from above the front side X1. FIG. 4 is a perspective view of the print head 3 as viewed obliquely from above the rear side X2. FIG. 5 is a perspective view of the print head 3 shown in FIG. 4 as viewed obliquely from below the front side X1. FIGS. 6 and 7 are exploded perspective views of the print head 3 shown in FIG. 4 as viewed obliquely from above the front side X1 and from below the rear side X2, respectively.

[0024] Fig. 8 is a cross-sectional perspective view of print head 3 viewed obliquely from above on the front side. Fig. 9 is a cross-sectional view of print head 3. Fig. 10 is a schematic diagram that clearly shows the cross-sectional view shown in Fig. 9. Fig. 11 is a plan view showing a state in which flexible circuit board 312a is extended linearly in light-emitting element panel 311, flexible circuit board 312a, and printed wiring board 312b that constitute print head 3.

[0025] In the following description, the plurality of light-emitting elements 31-31 in the print heads 3-3 will be described as organic light-emitting diodes (OLEDs: Organic Light-Emitting Diodes, hereinafter simply referred to as OLEDs). Note that the light-emitting elements 31-31 are not limited to OLEDs and may be inorganic light-emitting diodes (LEDs) or nano-scale light-emitting diodes (LEDs) that are smaller than a micrometer.

[0026] Since the print heads 3-3 etc. all have the same configuration, they are shown in a single drawing in FIGS. 3 to 11, and in the following description, the print heads 3-3 etc. will simply be referred to as print heads 3 etc.

[0027] The image forming apparatus 100 according to this embodiment includes a photosensitive drum 1 and a long print head 3. The print head 3 includes a light-emitting element panel 311 and a lens array 32. The light-emitting element panel 311 has a plurality of light-emitting elements 31-31 (see FIGS. 9 to 11). The light-emitting elements 31-31 emit light for exposing the surface 1a of the photosensitive drum 1. The light-emitting elements 31-31 are arranged in a line in the longitudinal direction L of the print head 3. In this example, the light-emitting element panel 311 is a film-like panel (flexible OLED panel) (light-emitting element panel) on which OLED elements (31-31) are mounted. This makes it possible to reduce the size and cost of the print head 3.

[0028] The lens array 32 extends in the longitudinal direction L and focuses the light emitted from the light emitting elements 31 onto the surface 1a of the photosensitive drum 1. The lens array 32 is disposed opposite the light emitting elements 31.

[0029] The print head 3 is provided on the bridge section 210. The bridge section 210 is installed between the main body frames FL (in this example, between the main body frame FL1 on the front side X1 and the main body frame FL2 on the rear side X2) of the image forming apparatus main body 101 (see FIG. 1).

[0030] In this example, a main body frame FL3 is installed between the main body frames FL1 and FL2 along the rotation axis direction X and the left-right direction Y. The installation portion 210 is placed on the main body frame FL3.

[0031] <Print head> As shown in Figures 8 to 11, the print head 3 further includes a driving member 312, a lens holding member 313, a fixed member 314 (base member), and a main body member 315. The fixed member 314 and the main body member 315 form a support member 316. The driving member 312 drives the light-emitting elements 31-31. The lens holding member 313 holds the lens array 32. The fixed member 314 fixes the lens holding member 313 while fixing the light-emitting element panel 311. The main body member 315 holds the driving member 312, the lens holding member 313, and the fixed member 314.

[0032] In this example, the driving member 312 includes a flexible circuit board 312a (connection cable member), a printed wiring board 312b (PWB: Printed Wiring Board) (connection board), a driving circuit element 312c, and a protective member 312d. One end of the connecting cable member 312a is connected to one end of the light-emitting element panel 311, and the other end is connected to one end of the printed wiring board 312b. The connecting cable member 312a is a flexible circuit board (COF: Chip on Film) on which a driving circuit element 312c (driver IC) that drives the OLED elements (31-31) on the light-emitting element panel 311 is mounted on a film. The printed wiring board 312b connected to the connecting cable member 312a has an input terminal 312b1 (see FIG. 10) (connector terminal) and is connected to a connector CN (see FIG. 10) via the input terminal 312b1. The protective member 312d protects the exposed portions of the light-emitting element panel 311 and the connecting cable member 312a. The connector CN is connected to an image processing device (not shown) provided in the image forming apparatus main body 101. In Fig. 10, the light emitting elements 31-31 are depicted as if they are provided protruding from the outer surface of the light emitting element panel 311, but this is for the purpose of making the light emitting elements 31-31 easier to understand, and in reality, as shown in Fig. 9, they are provided inside (by vapor deposition, for example) so as not to protrude from the outer surface of the light emitting element panel 311.

[0033] The lens holding member 313 is a frame-shaped member surrounding the outer peripheral surfaces 32a of the lens array 32 (see FIGS. 6 and 7) that are aligned along the optical axis direction N of the light-emitting elements 31. Here, the optical axis direction N is a direction (thickness direction) perpendicular to both the longitudinal direction L and width direction M of the print head 3. The width direction M is a direction perpendicular to the arrangement direction S of the linear arrangement of the plurality of light-emitting elements 31. The lens array 32 is inserted into an inner surface 313a of the frame-shaped lens holding member 313. At least a portion of the outer peripheral surfaces 32a (side surfaces 32a1, 32a1 along the longitudinal direction L in this example) of the lens array 32 is held by the lens holding member 313, and is bonded at least at some locations (multiple locations in this example) with an adhesive (e.g., an ultraviolet-curing adhesive). The periphery of the joint between the lens array 32 and the lens holding member 313 is sealed with a caulking agent (caulking resin). This effectively prevents foreign matter such as dust from entering the lens holding member 313 through the joint between the lens array 32 and the lens holding member 313 .

[0034] The fixing member 314 is formed in a rectangular parallelepiped shape. The back surface of the light-emitting element panel 311, on which the light-emitting elements 31-31 are provided, opposite the light-emitting elements 31-31, is adhered to a surface 314a of the fixing member 314 on the photosensitive drum 1 side (one side N1) in the optical axis direction N with an adhesive member E (e.g., double-sided adhesive tape) (see FIG. 10 ). A back surface 313c of the lens holding member 313 is fixed to a panel surface 311a of the light-emitting element panel 311 opposite the fixing member 314. The periphery of the joint between the lens holding member 313 and the light-emitting element panel 311 is sealed with a caulking agent (caulking resin). This effectively prevents foreign matter such as dust from entering the lens holding member 313 through the joint between the lens holding member 313 and the light-emitting element panel 311.

[0035] The relative positions (positions in the longitudinal direction L, width direction M, and optical axis direction N) of the plurality of light emitting elements 31 to 31 and the lens array 32 are adjusted in advance in the production process using a jig or the like.

[0036] The main body member 315 has an arrangement portion 315a, a bending portion 315b, and a panel guide portion 315c. The arrangement portion 315a, the bending portion 315b, and the panel guide portion 315c are integrally formed.

[0037] The arrangement portion 315a arranges the fixing member 314. The arrangement portion 315a is provided with an arrangement surface 315a1 on which the fixing member 314 is arranged so that the back surface 314b of the fixing member 314 on the bridge portion 210 side comes into contact. This allows the fixing member 314 to be reliably arranged on the arrangement surface 315a1 of the arrangement portion 315a. The arrangement surface 315a1 of the arrangement portion 315a is provided with a plurality (two) positioning protrusions or recesses (positioning protrusions 315a2, 315a2 in this example) (see FIG. 6). The back surface 314b of the fixing member 314 is provided with positioning recesses or protrusions (positioning recesses 314c, 314c in this example) (see FIG. 7) that correspond to the plurality (two) positioning protrusions or recesses (315a2, 315a2). This allows the fixing member 314 to be reliably positioned with respect to the main body member 315. The arrangement portion 315a is provided with a plurality of (two) holding portions 315a3 (see FIGS. 6, 7, and 9). The arrangement portion 315a and the holding portions 315a3 (315a3) are integrally formed. The holding portions 315a3 (315a3) detachably hold the fixing member 314 to the arrangement portion 315a. The holding portions 315a3 (315a3) restrict movement of the fixing member 314 toward the light emitting elements 31-31 (one side N1) in the optical axis direction N. The holding portions 315a3 (315a3) have locking portions 315a31 (see FIG. 9) that lock the surface 314a of the fixing member 314.

[0038] Bending portion 315b is bent at an acute angle (for example, 60 degrees or less, about 50 degrees in this example) with respect to arrangement portion 315a. Printed wiring board 312b is fixed to surface 315b1 (inner surface) of bending portion 315b facing arrangement portion 315a. Input terminal 312b1 is provided at the end of printed wiring board 312b on the entrance side (opening SPa side) of space SP between arrangement portion 315a and bending portion 315b, and connector CN is connected facing toward space SP.

[0039] The panel guide portion 315c has a curved portion 315c1 that folds the film-like protruding portion 317 from the support member 316 (314, 315) toward the space SP. The curved portion 315c1 is curved so that the lens holding member 313 side of the protruding portion 317 (between the light-emitting element panel 311 and the connection cable member (312a) in this example) is folded back at an angle of 180 degrees or more. The curved portion 315c1 protrudes beyond the lens holding member 313 to one side in the width direction M (the other side M2 ​​in this example). The panel portion 311b of the light-emitting element panel 311 on the connection cable member (312a) side and the portion of the connection cable member (312a) on the light-emitting element panel 311 side are bonded to the curved portion 315c1 with an adhesive member E. This allows the curved portion 315c1 to reliably fold back the protruding portion 317 (the connection cable member (312a) in this example) into the space SP. 6 and 7, the protective member 312d faces a portion of the protruding portion 317 that corresponds to the curved portion 315c1, and is curved along the curved portion 315c1. As shown in Fig. 6 and Fig. 7, the protective member 312d is fastened to the fastened portion 315e (female screw) of the main body member 315 on one side L1 in the longitudinal direction L by inserting a fastening member SC1 (male screw) through a through hole 312e1 of the holder 312e and a through hole 312d1 of the protective member 312d. This allows the end of the protective member 312d on the one side L1 in the longitudinal direction L to be fixed to the main body member 315.

[0040] Furthermore, the protective member 312d is fastened to the fastening portion 315e of the main body member 315 by inserting the fastening member SC1 through the through hole 312d1 of the protective member 312d on the other side L2 in the longitudinal direction L. This allows the end of the protective member 312d on the other side L2 in the longitudinal direction L to be fixed to the main body member 315. Furthermore, the printed wiring board 312b is positioned such that the positioning hole 312b2 of the printed wiring board 312b is matched with the positioning protrusion 315b2 of the bending portion 315b on the other side L2 in the longitudinal direction L. In this state, the printed wiring board 312b is fastened to the fastening portion 312e2 (female screw) of the holder 312e on one side L1 in the longitudinal direction L by inserting the fastening member SC2 through the through hole 315b3 of the bending portion 315b and the through recess 312b3 of the printed wiring board 312b. This allows the protective member 312d to be held in a state where it is positioned at the bent portion 315b.

[0041] The end of a part of the protruding portion 317 (connection cable member (312a)) provided in the space SP on the printed wiring board 312b side is folded back at the corner between the placement portion 315a and the bent portion 315b and connected to the printed wiring board 312b.

[0042] The drive circuit element 312c is provided on the arrangement portion 315a side of the connection cable member (312a). A recess 315a5 is provided on a surface 315a4 (inner surface) of the arrangement portion 315a facing the bent portion 315b to prevent interference with the drive circuit element 312c of the connection cable member (312a).

[0043] The main body member 315 is also provided with a pair of side plate portions 315f, 315g (see FIGS. 6 and 7) that close both ends in the longitudinal direction L of the space SP.

[0044] Next, a method for manufacturing the print head 3 will be described below with reference to FIGS.

[0045] 12 to 17 are perspective views illustrating an example of the first to sixth steps of the manufacturing process for print head 3. Note that Fig. 12 to 17 show the steps from providing lens array 32 on lens holding member 313, providing light-emitting element panel 311 on fixing member 314, and providing lens holding member 313 on light-emitting element panel 311.

[0046] In the method of manufacturing the print head 3, first, as shown in FIG. 12, the lens array 32 is inserted into the inner surface (313a) of the lens holding member 313 (in this example, the through-hole 3131 extending in the vertical direction Z) (first step).

[0047] 13, a dispenser 410 is used to evenly apply ultraviolet curing adhesive F to multiple locations in the peripheral area between the lens array 32 and the lens holding member 313, and then an ultraviolet irradiation device 420 is used to irradiate the ultraviolet curing adhesive F with ultraviolet rays UV to cure the ultraviolet curing adhesive F (second step). This allows the lens array 32 to be reliably held by the lens holding member 313.

[0048] 14, a caulking agent application device 430 is used to apply caulking agent G (caulking resin) to the peripheral area between the lens array 32 and the lens holding member 313 to seal the gap between the lens array 32 and the lens holding member 313 (third step). This makes it possible to prevent foreign matter such as dust from entering through the gap between the lens array 32 and the lens holding member 313.

[0049] Next, as shown in Figure 15, a roller pressing device 440 is used to attach the double-sided adhesive tape (E) (double-sided adhesive sheet) with a protective seal Ea attached to one side to the surface (314a) of the fixing member 314 on which the light-emitting element panel 311 is to be attached (fourth step).

[0050] Next, as shown in Figure 16, the protective seal Ea on one side of the double-sided adhesive tape (E) is peeled off, and with the multiple light-emitting elements 31 to 31 in the light-emitting element panel 311 positioned at the reference positioning position of the fixing member 314, the light-emitting element panel 311 is attached to the fixing member 314 using a roller pressure-bonding device 440 (fifth step).

[0051] 17, the lens holding member 313 holding the lens array 32, which was produced in the third step (see FIG. 14), is placed on the light emitting element panel 311 attached to the fixing member 314, and a caulking agent application device 430 is used to apply caulking agent G (caulking resin) to the peripheral area between the lens holding member 313 and the light emitting element panel 311 to seal the gap between the lens holding member 313 and the light emitting element panel 311 (sixth step). This makes it possible to prevent foreign matter such as dust from entering through the gap between the lens holding member 313 and the light emitting element panel 311.

[0052] (About this embodiment) 9 to 11, the print head 3 according to this embodiment includes a film-like light-emitting element panel 311 having a plurality of light-emitting elements 31 arranged in a line, a lens array 32 that focuses light emitted by the plurality of light-emitting elements 31 onto a photosensitive drum 1 (an example of an image carrier), and a fixing member 314 that fixes the light-emitting element panel 311. The fixing member 314 is made of a resin material.

[0053] Fig. 18 is a perspective view showing a state in which a light-emitting element panel 311 is provided on a fixing member 314. Fig. 19 is a perspective view showing the fixing member 314. Figs. 20 to 23 are perspective views showing ribs 314d of a first mode, a second mode, a third mode, and a fourth mode, respectively, provided on the back surface 314b of the fixing member 314. Note that the rib on the back surface 314b of the fixing member 314 shown in Fig. 7 represents the fourth mode shown in Fig. 23.

[0054] A rib 314d (see FIGS. 20 to 23) is provided on the surface (rear surface 314b) of the fixing member 314 opposite to the light emitting element panel 311 side.

[0055] The first embodiment of rib 314d shown in Figure 20 extends outward from the multiple light-emitting elements 31-31 along the arrangement direction S (longitudinal direction L) and includes ribs 314d1 and 314d2 arranged side by side in multiple rows (two rows in this example) in the width direction M.

[0056] The rib 314d of the second embodiment shown in FIG. 21 includes ribs 314d3 and 314d4 formed in a rounded wave shape in the arrangement direction S on both sides in the width direction M.

[0057] The rib 314d of the third embodiment shown in Figure 22 includes at least two (two in this example) ribs 314d5, 314d6, and the ribs 314d5, 314d6 extend in a direction intersecting the arrangement direction S so as to intersect at the same inclination angle with the center in the width direction M of the fixing member 314 as the intersection point β to β, and multiple sets (five sets in this example) of the intersecting ribs 314d5, 314d6 are connected in the arrangement direction S at both ends in the width direction M.

[0058] A rib 314d of a fourth embodiment shown in FIG. 23 further includes a rib 314d7 that passes through the intersection β-β of the ribs 314d5, 314d5 in the fixing member 314 shown in FIG.

[0059] As mentioned above, when the fixing member 314 is made of a resin material, a certain degree of strength is required to prevent deformation of the fixing member 314. For this reason, strength is ensured by providing ribs 314d on the surface (back surface 314b) of the fixing member 314 opposite the light emitting element panel 311 side. However, as shown in Fig. 38, due to the shape of the ribs, displacement portions 314e (particularly recesses, so-called sink marks due to the ribs) occur in the locations corresponding to the ribs 314d on the surface (front surface 314a) of the fixing member 314 on which the light emitting element panel 311 is provided.

[0060] The film-like light-emitting element panel 311 according to this embodiment is very thin, for example, about 0.14 mm, and is adhered (bonded) to the fixing member 314. Therefore, if a displacement portion 314e (especially a sink mark) occurs in the fixing member 314 due to the rib shape, the light-emitting element panel 311 will be deformed (for example, wavy) by the displacement portion 314e (see FIG. 39).

[0061] Fig. 24 and Fig. 25 are a plan view and a bottom view, respectively, showing the positional relationship of a first comparative example between the ribs 314d1, 314d2 of the first mode shown in Fig. 20 and the plurality of light-emitting elements 31. Fig. 26 and Fig. 27 are a plan view and a bottom view, respectively, showing the positional relationship of a second comparative example between the ribs 314d5, 314d6 of the third mode shown in Fig. 22 and the plurality of light-emitting elements 31. Fig. 28 and Fig. 29 are a plan view and a bottom view, respectively, showing the positional relationship of a third comparative example between the ribs 314d5, 314d6, 314d7 of the fourth mode shown in Fig. 23 and the plurality of light-emitting elements 31.

[0062] 24 and 25, the light-emitting elements 31-31 have their light-emitting points 31a-31a all provided in a portion corresponding to the displacement portion 314e of the light-emitting element panel 311. That is, the light-emitting points 31a-31a all overlap the rib region α (α1 or α2, α1 in the illustrated example) corresponding to the ribs 314d1 and 314d2, and the light-emitting element panel 311 is deformed by the displacement portion 314e.

[0063] In the positional relationship of the second comparative example shown in Figures 26 and 27, a portion of each light-emitting point 31a~31a of the multiple light-emitting elements 31~31 overlaps the rib region α (α3) corresponding to the intersection β~β of the ribs 314d5, 314d6, and the light-emitting element panel 311 is deformed by the displacement portions 314e~314e corresponding to the intersection β~β.

[0064] 28 and 29, the positional relationship of the third comparative example is a combination of the positional relationship of the first comparative example and the positional relationship of the second comparative example. Therefore, the thickness h (see FIG. 39) of the intersection β to β is larger than in the positional relationship of the first comparative example and the positional relationship of the second comparative example, and the displacement of the displacement portion 314e corresponding to the intersection β to β is accordingly larger, and ultimately the deformation of the light-emitting element panel 311 by the displacement portion 314e is larger.

[0065] 39, when the light-emitting element panel 311 is deformed by the displacement portion 314e, the positional relationship between the lens array 32 and each of the light-emitting points 31a-31a of the light-emitting elements 31-31 of the plurality of light-emitting elements 31-31 in the portion of the light-emitting element panel 311 that corresponds to the displacement portion 314e is lost (the focal length with the lens array 32 is shifted), resulting in portions where the focus is unacceptable at each image height. Therefore, problems such as an insufficient beam diameter on the surface 1a of the photosensitive drum 1 occur when light emitted from the plurality of light-emitting elements 31-31 is irradiated onto the surface 1a of the photosensitive drum 1.

[0066] In this regard, the present embodiment has the following configuration, which will be described below with reference to Figures 30 to 34.

[0067] [First embodiment] Fig. 30 and Fig. 31 are a plan view and a bottom view, respectively, showing the positional relationship of the first embodiment-1 between the ribs 314d1, 314d2 of the first mode shown in Fig. 20 and the plurality of light-emitting elements 31. Fig. 32 and Fig. 33 are a plan view and a bottom view, respectively, showing the positional relationship of the first embodiment-2 between the ribs 314d3, 314d4 of the second mode shown in Fig. 21 and the plurality of light-emitting elements 31.

[0068] In this embodiment, the plurality of light-emitting elements 31-31 are provided on the light-emitting element panel 311 so that none of the light-emitting points 31a-31a overlaps the rib regions α (α1, α2) corresponding to the ribs 314d (314d1, 314d2), (314d3, 314d4).

[0069] According to this embodiment, even if the light-emitting element panel 311 is deformed (e.g., wavy) due to the displacement portion 314e (especially sink marks), the light-emitting elements 31 are arranged on the light-emitting element panel 311 so that none of the light-emitting points 31a overlaps the rib region α (α1, α2) corresponding to the rib 314d ((314d1, 314d2), (314d3, 314d4)). This maintains the positional relationship between the lens array 32 and the light-emitting points 31a of the light-emitting elements 31, thereby reducing or eliminating areas where focus is not permitted at each image height. This effectively prevents problems such as poor beam diameter on the surface 1a of the photosensitive drum 1 when light emitted by the light-emitting elements 31 is irradiated onto the surface 1a of the photosensitive drum 1.

[0070] (First embodiment-1) However, if the rib 314d is inclined with respect to the arrangement direction S along the linear direction of the multiple light-emitting elements 31~31, when designing the light-emitting element panel 311, in order to prevent each of the light-emitting points 31a~31a of the multiple light-emitting elements 31~31 from overlapping with the rib region α corresponding to the rib 314d, the length of the multiple light-emitting elements 31~31 in the arrangement direction S will be limited.

[0071] In this regard, in the first embodiment-1 shown in FIGS. 30 and 31, the ribs 314d1 and 3142 are formed linearly so as to extend in the arrangement direction S of the plurality of light emitting elements 31-31.

[0072] In this configuration, even if the length of the plurality of light-emitting elements 31-31 in the arrangement direction S is increased, it is possible to prevent the light-emitting points 31a-31d of the plurality of light-emitting elements 31-31 from overlapping with the rib regions α1, α2 corresponding to the ribs 314d1, 314d2. This makes it possible to design the light-emitting element panel 311 without considering restrictions on the length of the plurality of light-emitting elements 31-31 in the arrangement direction S.

[0073] (First embodiment-2) In the first embodiment-2 shown in FIGS. 32 and 33, the ribs 314d3 and 314d4 are formed in a circular wave shape or a triangular wave shape (circular wave shape in this example) in the arrangement direction S of the plurality of light emitting elements 31-31.

[0074] In this configuration, the circular wave or triangular wave ribs 314d3, 314d4 can improve the strength of the fixing member 314 compared to the ribs 314d1, 314d2 of the first embodiment-1, while preventing the light emitting points 31a-31a of the multiple light emitting elements 31-31 from overlapping with the rib regions α1, α2 corresponding to the ribs 314d3, 314d4.

[0075] (First embodiment-3) In the first embodiment shown in Figures 30 to 33, the rib 314d includes two or more (two in this example) ribs (314d1, 314d2), (314d3, 314d4) provided on both sides of the multiple light-emitting elements 31-31 in the width direction M.

[0076] More specifically, in the first embodiment-1 shown in Figs. 30 and 31, the plurality of light-emitting elements 31-31 are provided between two linear ribs 314d1, 314d2 in the width direction M (in this example, the middle part). In the first embodiment-2 shown in Figs. 32 and 33, the plurality of light-emitting elements 31-31 are provided between two circular wave-shaped or triangular wave-shaped ribs 314d3, 314d4 in the width direction M (in this example, the middle part). The ribs (314d1, 314d2) of the first embodiment-1 and the ribs (314d3, 314d4) of the first embodiment-1 may be combined.

[0077] In this configuration, two or more ribs (314d1, 314d2), (314d3, 314d4) are provided on both sides of the multiple light-emitting elements 31~31 in the width direction M, so that the strength of the fixing member 314 is ensured on both sides in the width direction M while preventing each light-emitting point 31a~31a of the multiple light-emitting elements 31~31 from overlapping the rib areas (α1, α2) corresponding to the ribs (314d1, 314d2), (314d3, 314d4).

[0078] (First embodiment-4) The depth of the displacement portion 314e on the surface of the fixing member 314 on which the light-emitting element panel 311 is provided becomes shallower with increasing distance from the displacement portion 314e. For example, if the displacement portion 314e is located further away from the region four times the thickness h of the rib 314d (see FIG. 39), deformation of the light-emitting element panel 311 can be effectively prevented. Here, "the region four times the thickness h of the rib 314d" refers to the region extending from the center of the maximum thickness h of the rib 314d to within four times the maximum thickness h.

[0079] In this regard, in the present embodiment, the plurality of light emitting elements 31-31 are provided so as to be positioned in an area other than an area four times the thickness h of the rib 314d.

[0080] This effectively prevents deformation of the light-emitting element panel 311, thereby maintaining the positional relationship between the lens array 32 and each of the light-emitting points 31a-31a of the multiple light-emitting elements 31-31, and ultimately eliminating areas where focus is not permitted at each image height.

[0081] [Second embodiment] Fig. 34 and Fig. 35 are a plan view and a bottom view, respectively, showing the positional relationship of the second embodiment-1 between the ribs 314d5, 314d6 and the plurality of light-emitting elements 31, in which the positions of the intersections β to β are shifted to either side in the width direction M in the third mode shown in Fig. 22. Fig. 36 and Fig. 37 are a plan view and a bottom view, respectively, showing the positional relationship of the second embodiment-2 between the ribs 314d5, 314d6, 314d7 and the plurality of light-emitting elements 31, in which the positions of the intersections β to β are shifted to either side in the width direction M in the fourth mode shown in Fig. 23.

[0082] 34 and 35, the ribs 314d5 and 314d6 extend in a direction intersecting the width direction M, and the intersections β-β between the ribs 314d5 and 314d6 are shifted to one side (one side M1 in this example) in the width direction M. In addition, in the second embodiment-2 shown in Fig. 36 and 33, the rib 314d7 in the second embodiment-1 passes through the intersections β-β between the ribs 314d5 and 314d6 and extends outward from the plurality of light-emitting elements 31-31 along the arrangement direction S.

[0083] In this embodiment, at least two ribs (two ribs 314d5, 314d6 in second embodiment-1, and three ribs 314d5, 314d6, 314d7 in second embodiment-2) are arranged to intersect on the surface (rear surface 314b) of the fixing member 314 opposite the light-emitting element panel 311 side. Incidentally, the depth of the displacement portion 314e (314e1) in the intersection region α3 corresponding to the intersection β-β where at least two ribs intersect is deeper than the displacement portion 314e (314e2) in the rib regions (α1, α2) other than the intersection region α3. In this case, even if the portion of the light-emitting element panel 311 corresponding to the displacement portion 314e2 in the rib regions (α1, α2) other than the intersection region α3 can tolerate a shift in focal length, the portion of the light-emitting element panel 311 corresponding to the displacement portion 314e1 in the intersection region α3 may not be able to tolerate a shift in focal length.

[0084] In this regard, the multiple light-emitting elements 31-31 are arranged on the light-emitting element panel 311 so that none of the light-emitting points 31a-31a overlaps the intersection region α3 corresponding to the intersection β-β where at least two ribs (314d5, 314d6), (314d5, 314d6, 314d7) intersect.

[0085] According to this embodiment, even if the light-emitting element panel 311 is deformed by the displacement portion 314e (314e1, 314e2), the plurality of light-emitting elements 31 are provided in the light-emitting element panel 311 so that none of the light-emitting points 31a-31a of the plurality of light-emitting elements 31-31 overlaps the intersection region α3 corresponding to the intersection region β-β where at least two ribs (314d5, 314d6), (314d5, 314d6, 314d7) intersect. Therefore, in regions other than the rib regions α (α1-α3) corresponding to the ribs (314d5, 314d6), (314d5, 314d6, 314d7) of the light-emitting element panel 311, the positional relationship between the lens array 32 and the light-emitting points 31a-31a of the plurality of light-emitting elements 31-31 can be maintained, and therefore, it is possible to reduce or eliminate portions where focusing is not permitted at each image height. This effectively prevents problems such as an insufficient beam diameter on the surface 1a of the photosensitive drum 1 when light emitted from the plurality of light-emitting elements 31-31 is irradiated onto the surface 1a of the photosensitive drum 1. Furthermore, it is possible to allow deviation in focal length in the portion corresponding to the displacement portion 314e2 of the rib region (α1, α2) other than the intersection region α3 of the light-emitting element panel 311, thereby reducing or eliminating portions where focus is not allowed at each image height. This effectively prevents problems such as an insufficient beam diameter on the surface 1a of the photosensitive drum 1 when light emitted from the plurality of light-emitting elements 31-31 is irradiated onto the surface 1a of the photosensitive drum 1.

[0086] (Second embodiment-1) However, if at least two ribs (314d5, 314d6), (314d5, 314d6, 314d7) include inclined ribs (314d5, 314d6) inclined with respect to the arrangement direction S of the multiple light-emitting elements 31~31, when designing the light-emitting element panel 311, the length of the multiple light-emitting elements 31~31 in the arrangement direction S is limited in order to prevent each light-emitting point 31a~31a of the multiple light-emitting elements 31~31 from overlapping with the rib areas α (α1~α3) corresponding to the ribs (314d5, 314d6), (314d5, 314d6, 314d7).

[0087] In this regard, in this embodiment, the multiple light-emitting elements 31-31 are arranged on the light-emitting element panel 311 so that a portion of each light-emitting point 31a-31a overlaps with the inclined rib regions (α1, α2) other than the intersection region α3 of the inclined rib regions (α1-α3) corresponding to the inclined ribs (314d5, 314d6).

[0088] In this configuration, even if the length of the plurality of light-emitting elements 31-31 in the arrangement direction S is increased, the light-emitting points 31a-31a of the plurality of light-emitting elements 31-31 can be made to partially overlap with the inclined rib regions (α1, α2) other than the intersection region α3 of the inclined rib regions (α1-α3). This makes it possible to allow deviation in focal length in the portion corresponding to the displacement portion 314e2 of the inclined rib regions (α1, α2) other than the intersection region α3 of the light-emitting element panel 311, and ultimately reduces or eliminates the portion where focus is not allowed at each image height.

[0089] 36 and 37, an arrangement direction rib (314d7) extending along the arrangement direction S of the plurality of light emitting elements 31-31 is further provided on the surface (rear surface 314b) opposite the light emitting element panel 311 side of the fixing member 314. The arrangement direction rib (314d7) intersects with the inclined ribs (314d5, 314d6) at intersections β-β.

[0090] (Second embodiment-2) 34 to 37, the intersections β-β are located on one side (one side M1 in this example) of the fixing member 314 in the width direction M of the plurality of light-emitting elements 31-31. The plurality of light-emitting elements 31-31 are provided so that their light-emitting points are located on the other side (center side) of the intersections β-β of the fixing member 314 in the width direction M.

[0091] This allows the plurality of light emitting elements 31 to be provided closer to the center of the fixing member 314 in the width direction M than the intersections β to β (in this example, at the center position).

[0092] 34 to 37, the intersections β to β may be positioned in the center of the fixing member 314 in the width direction M. In this case, the plurality of light-emitting elements 31 to 31 can be provided on either side of the fixing member 314 in the width direction M.

[0093] [Third embodiment] Incidentally, examples of resin materials used for the fixing member 314 include resin materials (such as liquid crystal polymers) that are excellent in strength, deformation resistance, rigidity, and heat resistance and that are less likely to cause the displacement portion 314e (especially sink marks).

[0094] By doing so, the resin material used for the fixing member 314 can be a resin material (in this example, a liquid crystal polymer material) that is less likely to produce displacement portions 314e, which makes it possible to maintain the positional relationship between the lens array 32 and each of the light-emitting points 31a-31a of the multiple light-emitting elements 31-31, and ultimately reduces or eliminates the areas where focus is not permitted at each image height.

[0095] (Third embodiment-1) In this embodiment, no protrusions are provided (the surface 314a) of the fixing member 314 in the area where the light-emitting element panel 311 is provided is flat. The height difference of the concaves and convexes on the surface (314a) of the fixing member 314 in the area where the light-emitting element panel 311 is provided can be, for example, equal to or less than the focal depth of the lens array 32.

[0096] In this configuration, the surface (314a) of the fixing member 314 in the area where the light-emitting element panel 311 is provided has no protrusions (it is flat), so the positional relationship between the lens array 32 and each of the light-emitting points 31a-31a of the multiple light-emitting elements 31-31 can be maintained, and ultimately, areas where focus is not permitted at each image height can be eliminated.

[0097] The present disclosure is not limited to the above-described embodiments, but can be implemented in various other forms. Therefore, the embodiments are merely examples in all respects and should not be interpreted as being limiting. The scope of the present disclosure is defined by the claims and is not bound by the text of the specification. Furthermore, all modifications and variations within the equivalent scope of the claims are within the scope of the present disclosure. [Explanation of symbols]

[0098] 1. Photosensitive drum (an example of an image carrier) 100 Image forming device 1a surface 3 print head 31 Light-emitting element 311 Light-emitting element panel 314 Fixing member 314a surface 314b back 314c Positioning recess 314d Rib 314d1 Rib 314d2 Rib 314d3 Rib 314d4 Rib 314d5 Rib 314d6 Rib 314d7 Rib 314e Displacement section 314e1 Displacement section 314e2 Displacement section 31a Light-emitting point 32 Lens Array 410 Dispenser 420 Ultraviolet irradiation device 430 Caulking agent application device 440 Roller pressure device L Longitudinal direction L1 One side L2 other side M Width direction M1 One side M2 Other side N Optical axis direction S array direction X rotation axis direction Y left / right direction Z vertical direction h Rib thickness α rib region α1 rib region α2 rib region α3 crossover region β intersection

Claims

1. A print head comprising: a film-shaped light-emitting element panel having a plurality of light-emitting elements arranged in a line; a lens array that focuses light emitted by the plurality of light-emitting elements onto an image carrier; and a fixing member that fixes the light-emitting element panel, the fixing member is made of a resin material, a rib is provided on a surface of the fixing member opposite to the light-emitting element panel, The print head is characterized in that the plurality of light emitting elements are provided on the light emitting element panel so that none of the light emitting points overlaps a rib region corresponding to the rib.

2. 10. The printhead of claim 1, The print head is characterized in that the rib is formed linearly so as to extend in an arrangement direction along the linear direction of the plurality of light emitting elements.

3. 10. The printhead of claim 1, The print head is characterized in that the ribs are formed in a circular wave shape or a triangular wave shape in an arrangement direction along the linear direction of the plurality of light emitting elements.

4. 4. A printhead according to claim 1, further comprising: A print head characterized in that the ribs include two or more ribs provided on both sides of the plurality of light-emitting elements in a width direction perpendicular to the arrangement direction of the plurality of light-emitting elements along the linear direction.

5. 10. The printhead of claim 1, The print head is characterized in that the plurality of light-emitting elements are provided so as to be positioned in an area other than an area four times the width of the rib.

6. A print head comprising: a film-shaped light-emitting element panel having a plurality of light-emitting elements arranged in a line; a lens array that focuses light emitted by the plurality of light-emitting elements onto an image carrier; and a fixing member that fixes the light-emitting element panel, the fixing member is made of a resin material, At least two ribs are provided on a surface of the fixing member opposite to the light-emitting element panel so as to intersect with each other, The print head is characterized in that the plurality of light-emitting elements are provided on the light-emitting element panel so that none of the light-emitting points overlaps an intersection region corresponding to an intersection where the at least two ribs intersect.

7. 7. The printhead of claim 6, the at least two ribs include an inclined rib inclined with respect to an arrangement direction of the plurality of light-emitting elements along the linear direction, The print head is characterized in that the plurality of light-emitting elements are arranged on the light-emitting element panel so that a portion of each light-emitting point overlaps with an inclined rib region other than the intersection region of the inclined rib region corresponding to the inclined rib.

8. 8. The print head according to claim 6 or claim 7, the intersecting portion is located on either side of the fixing member in a width direction perpendicular to an arrangement direction along the linear direction, a plurality of light-emitting elements each having a light-emitting point positioned on the other side of the intersection of the fixing member in the width direction;

9. 10. The print head according to claim 1 or claim 6, The print head is characterized in that the resin material is a liquid crystal polymer.

10. 10. The print head according to claim 1 or claim 6, The print head is characterized in that no protrusions are provided on the surface of the fixing member in the area where the light emitting element panel is provided.

11. An image forming apparatus comprising the print head according to claim 1 or 6.

Images