Print head and image forming apparatus

Abstract

To provide a print head and an image forming apparatus which can effectively prevent noise from a high-voltage member, to which a predetermined high voltage is applied, from affecting a light emitting element substrate and hence light emission of a light emitting element.SOLUTION: The print head 3 includes the light emitting element substrate (311) having the plurality of light emitting elements 31 to 31 arranged in a line, the lens array 32 that condenses light emitted from the plurality of light emitting elements 31 to 31 onto the image carrier (1), and the lens holding member 313 that holds the lens array 32, and is included in the image forming apparatus 100 including the high-voltage member (201) to which a predetermined high voltage is applied. In the print head 3, the light-emitting-element substrate (311) is provided close to the high-voltage member (201), and the print head 3 includes the interposing member (312d) interposed between the light-emitting-element substrate (311) and the high-voltage member (201).SELECTED DRAWING: Figure 21

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 provided in an image forming device generally comprises a light-emitting element substrate 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 lens holding member that holds the lens array (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-127808 Summary of the Invention [Problem to be solved by the invention]

[0004] In such printheads, the focal length of the lens array is typically short, about 2.3 mm, and the distance between the light-emitting element substrate and the image carrier (e.g., a photosensitive drum) is short, so the light-emitting element substrate must be located close to the image carrier. This means that in image forming devices equipped with a high-voltage member (e.g., a charging member that charges the image carrier) to which a predetermined high voltage is applied, the light-emitting element substrate is located close to the high-voltage member, thereby shortening the distance between the light-emitting element substrate and the high-voltage member. Furthermore, as image forming devices become more compact, the distance between the light-emitting element substrate and the high-voltage member becomes even shorter. This can result in noise from the high-voltage member affecting the light-emitting element substrate and, ultimately, the light emission of the light-emitting elements.

[0005] In this regard, the print head described in Patent Document 1 does not take into consideration the influence of noise from the high-pressure member.

[0006] Therefore, the present disclosure aims to provide a print head and an image forming apparatus that can effectively prevent noise from a high-voltage component to which a predetermined high voltage is applied from affecting the light-emitting element substrate and, ultimately, the light emission of the light-emitting element. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present disclosure provides the following print head and image forming apparatuses of first and second aspects.

[0008] (1) Print head The print head according to the present disclosure is a print head comprising a light-emitting element substrate 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 lens holding member that holds the lens array, and is characterized in that the print head is provided in an image forming device that has a high-voltage member to which a predetermined high voltage is applied, the light-emitting element substrate is provided in close proximity to the high-voltage member, and an intervening member is provided between the light-emitting element substrate and the high-voltage member.

[0009] (2) Image forming apparatus of the first aspect An image forming apparatus according to a first aspect of the present disclosure is characterized by including the print head according to the present disclosure.

[0010] (3) Image forming apparatus according to the second aspect A second aspect of the image forming apparatus according to the present disclosure is an image forming apparatus comprising: a light emitting element substrate having a plurality of light emitting elements arranged in a line; a print head comprising: a lens array that focuses light emitted by the plurality of light emitting elements onto an image carrier; and a lens holding member that holds the lens array; and a high-voltage member to which a predetermined high voltage is applied, wherein the light emitting element substrate is provided in close proximity to the high-voltage member, and further comprising an intervening member interposed between the light emitting element substrate and the high-voltage member. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to effectively prevent the influence of noise from a high-voltage member to which a predetermined high voltage is applied on a light-emitting element substrate, and ultimately on the light emission of a light-emitting element. [Brief explanation of the drawings]

[0012] [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. 2 is a cross-sectional perspective view of a positioning portion and a positioned portion as viewed obliquely from above. [Figure 13] FIG. 4 is an enlarged view of a positioning portion and a positioned portion viewed obliquely from above. [Figure 14]FIG. 10 is a perspective view illustrating an example of a first step in the manufacturing process of the print head. [Figure 15] FIG. 10 is a perspective view illustrating an example of a second step in the manufacturing process of the print head. [Figure 16] FIG. 10 is a perspective view illustrating an example of a third step in the manufacturing process of the print head. [Figure 17] FIG. 10 is a perspective view illustrating an example of a fourth step in the manufacturing process of the print head. [Figure 18] FIG. 10 is a perspective view illustrating an example of a fifth step in the manufacturing process of the print head. [Figure 19] FIG. 10 is a perspective view illustrating an example of a sixth step in the manufacturing process of the print head. [Figure 20] FIG. 10 is a cross-sectional view showing a state in which no intervening member is interposed between the light-emitting element substrate and the high-voltage member. [Figure 21] 10 is a cross-sectional view showing a state in which an interposition member is interposed between a light-emitting element substrate and a high-voltage member. FIG. [Figure 22] 10 is a perspective view showing a state in which the gap between the lens holding member and the light-emitting element panel is not sealed with a sealant. FIG. [Figure 23] 10 is a cross-sectional view showing a state in which the gap between the lens holding member and the light-emitting element panel is not sealed with a sealant. FIG. [Figure 24] 10 is a cross-sectional view showing a state in which a gap between a lens holding member and a light-emitting element panel is sealed with a sealant. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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.

[0014] (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.

[0015] 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 (an example of an image carrier), four chargers 2, four print heads 3, four developing devices 4, four primary transfer devices 5, and four 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 corresponding to black, cyan, magenta, and yellow, respectively. Note that the image forming apparatus 100 may also be a monochrome image forming apparatus.

[0016] 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 .

[0017] 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.

[0018] 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.

[0019] 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.

[0020] Fig. 8 is a cross-sectional perspective view of the print head 3 viewed obliquely from above on the front side. Fig. 9 is a cross-sectional view of the 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 the light-emitting element panel 311 (light-emitting element substrate), flexible circuit board 312a, and printed wiring board 312b that make up the print head 3, with flexible circuit board 312a extended linearly.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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).

[0026] 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.

[0027] <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.

[0028] 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.

[0029] 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 .

[0030] The fixing member 314 is formed in a rectangular parallelepiped shape. A back surface 313c (the other side N2) of the light-emitting element panel 311, on which the light-emitting elements 31-31 are provided, of the light-emitting element panel 311 is adhered to a surface 314a on the photosensitive drum 1 side (one side N1) in the optical axis direction N of the fixing member 314 with an adhesive member E (e.g., double-sided adhesive tape) (see FIG. 10). A back surface 313c (the other side N2) of the lens holding member 313 is fixed to a panel surface 311a of the light-emitting element panel 311 on the side 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The panel guide portion 315c has a curved portion 315c1 that folds back 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 either one side M1 or the other side M2 ​​in the width direction M (the other side M2 ​​in this example). A panel portion 311b of the light-emitting element panel 311 on the connection cable member (312a) side and a portion of the connection cable member (312a) on the light-emitting element panel 311 side are adhered to the curved portion 315c1 with an adhesive member E. As a result, the curved portion 315c1 can reliably fold back the protruding portion 317 (the connection cable member (312a) in this example) into the space SP. The protective member 312d faces a portion of the protruding portion 317 that corresponds to the curved portion 315c1 and curves along the curved portion 315c1. As shown in FIGS. 6 and 7, the protective member 312d has a fastening member SC1 (male screw) inserted through the through-hole 312e1 of the holder 312e and the through-hole 312d1 of the protective member 312d on one side L1 in the longitudinal direction L, and is fastened to the fastened portion 315e (female screw) of the main body member 315. This allows the end of the protective member 312d on one side L1 in the longitudinal direction L to be fixed to the main body member 315.

[0036] 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.

[0037] 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.

[0038] 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).

[0039] 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.

[0040] 12 and 13 are a cross-sectional perspective view and an enlarged view, respectively, of the positioning portion 301 and the positioned portion 302 as viewed obliquely from above.

[0041] In this embodiment, image forming apparatus 100 further includes a positioning mechanism 300 (an example of a positioning means). Positioning mechanism 300 positions print head 3 with respect to photosensitive drum 1 so as to maintain a constant distance between print head 3 and photosensitive drum 1. Positioning mechanism 300 includes a positioning portion 301 and a positioned portion 302. Positioning portion 301 is provided on print head 3 and determines the position of print head 3 with respect to photosensitive drum 1. Positioned portion 302 is provided on a main body member (in this example, housing 401 of photosensitive drum unit 400) that is a member on the main body side of image forming apparatus 100, and abuts against positioning portion 301. Positioned portion 302 has an arc-shaped portion 3021.

[0042] Next, a method for manufacturing the print head 3 will be described below with reference to FIGS.

[0043] 14 to 19 are perspective views illustrating an example of the first to sixth steps of the manufacturing process for print head 3. Note that Fig. 14 to 19 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.

[0044] In the method for manufacturing the print head 3, first, as shown in FIG. 14, 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).

[0045] 15, 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.

[0046] 16, 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.

[0047] Next, as shown in Figure 17, 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).

[0048] Next, as shown in Figure 18, 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).

[0049] 19, the lens holding member 313 holding the lens array 32, which was produced in the third step (see FIG. 16), is placed on the light emitting element panel 311 attached to the fixing member 314, and a caulking agent G (caulking resin) is applied to the peripheral area between the lens holding member 313 and the light emitting element panel 311 using a caulking agent application device 430 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.

[0050] <About this implementation> The print head 3 according to this embodiment includes a light emitting element substrate (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 the photosensitive drum 1, and a lens holding member 313 that holds the lens array 32. The print head 3 is provided in an image forming apparatus 100 that includes a high voltage member (in this example, the charging member 201 of the charger 2) to which a predetermined high voltage (for example, about 500 V to 2 kV) is applied.

[0051] 20 and 21 are cross-sectional views showing a state where an intervening member (312d) is not interposed between the light-emitting element substrate (311) and the high-voltage member (201) and a state where an intervening member (312d) is interposed therebetween, respectively.

[0052] The light-emitting element substrate (311) is provided close to the high-voltage member (201) (for example, at a distance of approximately 3 mm to 10 mm in the shortest straight line between the light-emitting element substrate (311) and the high-voltage member (201) (spatial distance da shown in FIG. 20)). The print head 3 includes an intervening member (protective member 312d in this example) interposed between the light-emitting element substrate (311) and the high-voltage member (201). The intervening member (312d) may also be provided on a member on the image forming apparatus main body 101 side (for example, the housing of the charger 2 or the frame of the image forming apparatus main body 101).

[0053] According to this embodiment, the interposing member (312d) is interposed between the light-emitting element substrate (311) and the high-voltage member (201), and therefore the interposing member (312d) can effectively block noise from the high-voltage member (201). That is, if the interposing member (312d) is an insulating member, it is possible to ensure the spatial distance of the insulation distance between the light-emitting element substrate (311) and the high-voltage member (201). Alternatively, if the interposing member (312d) is a conductive member and is grounded (connected to ground), the grounded conductive interposing member (312d) can act as an electrostatic shield. That is, electric charges accumulated in the high-voltage member (201) can be discharged (bypassed to ground) via the interposing member (312d).

[0054] Therefore, it is possible to effectively prevent noise from the high voltage member (201) from affecting the light emitting element substrate (311) and, in turn, the light emission of the light emitting elements 31-31.

[0055] Here, the "insulation distance" between the light-emitting element substrate (311) and the high-voltage member (201) is affected by factors such as the strength of insulation, the magnitude of overvoltage, the degree of contamination, and tracking resistance. This "insulation distance" can be determined by the "spatial distance" and the "creepage distance." Here, the "spatial distance" refers to the shortest distance of the spatial path between the high-voltage member (201) and the light-emitting element substrate (311). In this example, the "spatial distance" refers to the shortest distance of the spatial path between the surface 201a of the charging roller (201), which acts as the high-voltage member, and the protruding portion 317 of the light-emitting element substrate (311).

[0056] Specifically, as shown in Fig. 20, when no intervening member (312d) is interposed between the protruding portion 317 of the light-emitting element substrate (311) and the high-voltage member (201), the spatial distance da (see the bold line in Fig. 20) is 3 mm, which does not meet the standard spatial distance (7.2 mm, which is a design margin of +20% of the 6.0 mm specified in the safety standard). In contrast, as shown in Fig. 21, when an intervening member (312d) is intervened between the protruding portion 317 of the light-emitting element substrate (311) and the high-voltage member (201), the spatial distance db (= d1 + d2 + d3 + d4 + d5) (see the bold line in Fig. 21) is 13.7 mm, which meets the standard spatial distance (7.2 mm, which is a design margin of +20% of the 6.0 mm specified in the safety standard).

[0057] When the interposing member 312d is an insulating member, the insulating material usable for the insulating interposing member 312d is not particularly limited, but examples thereof include flame-retardant materials (equivalent to flame-retardant standard V-0) such as PI (polyimide) and PPSU (polyphenylsulfone). When the interposing member 312d is a conductive member, typical examples of the conductive material usable for the conductive interposing member 312d include metal materials. Examples of metal materials include, but are not limited to, sheet metal, stainless steel, and aluminum.

[0058] First Embodiment In this embodiment, the light emitting element substrate is a film-shaped light emitting element panel 311. A high voltage member (201) is located on either one side M1 or the other side M2 ​​in a width direction M perpendicular to the arrangement direction S of the plurality of light emitting elements 31. The light emitting element panel 311 extends toward either one of the high voltage members (201) in the width direction.

[0059] Incidentally, when the light-emitting element panel 311 is extended toward either one of the high-voltage members (201) in the width direction, if there is no intervening member (312d) between the light-emitting element panel 311 and the high-voltage member (201), the spatial distance da (see Figure 20) between the light-emitting element panel 311 and the high-voltage member (201) becomes even shorter, making it even more susceptible to the effects of noise from the high-voltage member (201).

[0060] In this regard, in the present embodiment, since the interposing member (312d) is interposed between the light-emitting element panel 311 and the high-voltage member (201), if the interposing member (312d) is an insulating member, the spatial distance db (see FIG. 21) between the light-emitting element panel 311 and the high-voltage member (201) can be ensured. Alternatively, if the interposing member (312d) is a conductive member and is grounded, the grounded conductive interposing member (312d) can act as an electrostatic shield. This effectively prevents the effects of noise from the high-voltage member (201).

[0061] Second Embodiment In this embodiment, the print head 3 further includes a support member 316 that supports the light-emitting element panel 311. The end of the support member 316 on the high-voltage member (201) side is provided with a curved portion 315c1 that is curved so as to be convex toward the high-voltage member (201). The light-emitting element panel 311 is provided along the curved portion 315c1 of the support member 316.

[0062] Incidentally, when the light-emitting element panel 311 is arranged along the curved portion 315c1 of the support member 316, if there is no intervening member (312d) between the light-emitting element panel 311 and the high-voltage member (201), the spatial distance da (see Figure 20) between the light-emitting element panel 311 and the high-voltage member (201) becomes even shorter, making it even more susceptible to the effects of noise from the high-voltage member (201).

[0063] In this regard, in the present embodiment, since the interposing member (312d) is interposed between the light-emitting element panel 311 and the high-voltage member (201), if the interposing member (312d) is an insulating member, the spatial distance db (see FIG. 21) between the light-emitting element panel 311 and the high-voltage member (201) can be ensured. Alternatively, if the interposing member (312d) is a conductive member and is grounded, the grounded conductive interposing member (312d) can act as an electrostatic shield. This effectively prevents the effects of noise from the high-voltage member (201).

[0064] Third Embodiment In this embodiment, the light emitting element panel 311 has a protruding portion 317 that protrudes beyond the lens holding member 313 toward the high voltage member (201).

[0065] Incidentally, when the protruding portion 317 of the light-emitting element panel 311 protrudes toward the high-voltage member (201), if there is no intervening member (312d) between the light-emitting element panel 311 and the high-voltage member (201), the spatial distance da (see Figure 20) between the light-emitting element panel 311 and the high-voltage member (201) becomes even shorter, making it even more susceptible to the effects of noise from the high-voltage member (201).

[0066] In this regard, in the present embodiment, since the interposing member (312d) is interposed between the light-emitting element panel 311 and the high-voltage member (201), if the interposing member (312d) is an insulating member, the spatial distance db (see FIG. 21) between the light-emitting element panel 311 and the high-voltage member (201) can be ensured. Alternatively, if the interposing member (312d) is a conductive member and is grounded, the grounded conductive interposing member (312d) can act as an electrostatic shield. This effectively prevents the effects of noise from the high-voltage member (201).

[0067] <Fourth embodiment> However, as the image forming apparatus 100 becomes smaller, the space in which the print head 3 is installed (for example, for insertion from one side L1 to the other side L2 in the longitudinal direction L) becomes narrow. For this reason, when the print head 3 is assembled into the image forming apparatus main body 101, if the protruding portion 317 of the light-emitting element panel 311 protrudes toward the high-voltage member (201), it is likely to come into contact with the high-voltage member (201). This can lead to a break in the protruding portion 317.

[0068] In this regard, in the present embodiment, the interposing member (312d) is a protective cover member that covers the protruding portion 317 of the light-emitting element panel 311.

[0069] In this configuration, by using the intervening member (312d) as a protective cover member that covers the protruding portion 317, the effects of noise from the high-voltage member (201) can be effectively prevented. In addition, when assembling the print head 3 to the image forming apparatus main body 101, if the protruding portion 317 of the light-emitting element panel 311 protrudes toward the high-voltage member (201), the protective cover member (312d) can prevent the protruding portion 317 from coming into contact with the high-voltage member (201), thereby effectively preventing breakage of the protruding portion 317.

[0070] In this example, the protective cover member (312d) is formed in a plate shape. If the protective cover member (312d) is an insulating member, the spatial distance db between the light-emitting element panel 311 and the high-voltage member (201) can be ensured. If the protective cover member (312d) is a conductive member, one end of the protective cover member (312d) is grounded to the grounded main frame FL, and the grounded conductive protective cover member (312d) can act as an electrostatic shield. This effectively prevents the influence of noise from the high-voltage member (201).

[0071] Fifth Embodiment FIG. 22 is a perspective view showing a state in which the gap f between the lens holding member 313 and the light-emitting element panel 311 is not sealed with a sealant (in this example, caulking agent G). FIGS. 23 and 24 are cross-sectional views showing a state in which the gap f between the lens holding member 313 and the light-emitting element panel 311 is not sealed with a sealant (G) and is sealed, respectively. In this example, the sealant (G) is made of a flame-retardant material (equivalent to flame-retardant standard V-0) and is made of a caulking resin. The lens holding member 313 and the fixing member 314 are made of a flame-retardant material (equivalent to flame-retardant standard V-0) and are made of a liquid crystal polymer (LCP). The main body member 315 is made of a flame-retardant material (equivalent to flame-retardant standard V-1 or higher) and is made of a resin material that is a mixture of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS). The charging roller bearing 202 that supports the charging roller (201) is made of a flame-retardant material (equivalent to the flame-retardant standard UL94-HB) and is made of polyacetal (POM) resin. In this embodiment, a gap f is provided between the light-emitting element panel 311 supported by the support member 316 and the lens holding member 313. The gap f is sealed with a sealant (G).

[0072] In this configuration, it is possible to effectively prevent foreign matter such as dust from entering the lens holding member 313 through the gap f between the lens holding member 313 and the light emitting element panel 311 .

[0073] If the gap f between the light-emitting element panel 311 and the lens holding member 313 is not sealed with the sealant (G), the creepage distance ea (see FIG. 23) between the light-emitting element panel 311 and the high-voltage member (201) becomes shorter, making the panel more susceptible to noise from the high-voltage member (201). Here, the "creepage distance" refers to the shortest distance along the surface of the insulating member between the high-voltage member (201) and the light-emitting element panel 311. In this example, the "creepage distance" refers to the shortest distance along the surface of the insulating member between the rotating shaft 201b of the charging roller (201) acting as the high-voltage member and the light-emitting element panel 311. The surfaces of the insulating member include the surface (e1) of the charging roller bearing 202, the surfaces (e2, e3, e4) of the arc-shaped portion 3021 of the positioned portion 302, the surface (e5) of the positioning portion 301, the surface (e6) of the lens holding member 313, and, in the example shown in FIG. 24, the surface (e7) of the sealant (G). That is, the charging roller bearing 202, the arc-shaped portion 3021 of the positioned portion 302, the positioning portion 301, the lens holding member 313, and the sealant (G) are all made of a resin material and act as insulating members.

[0074] In this regard, in the present embodiment, the gap f between the light-emitting element panel 311 and the lens holding member 313 is sealed with a sealant (G), so that the creepage distance eb (see Figure 24) between the light-emitting element panel 311 and the high-voltage member (201) can be secured, thereby effectively preventing the effects of noise from the high-voltage member (201).

[0075] 22 and 23, when the gap f between the lens holding member 313 and the light-emitting element panel 311 is not sealed with the sealant (G), the creepage distance ea (= e1 + e2 + e3 + e4 + e5 + e6) (see the bold line in FIGS. 22 and 23) is 23.5 mm, which does not meet the standard creepage distance (24 mm, which is a design margin of +20% of the 20 mm specified in the safety standard). In contrast, when the gap between the lens holding member 313 and the light-emitting element panel 311 is sealed with the sealant (G), as shown in FIG. 24, the creepage distance eb (= e1 + e2 + e3 + e4 + e5 + e6 + e7) (see the bold line in FIG. 24) is 25 mm, which meets the standard creepage distance (24 mm, which is a design margin of +20% of the 20 mm specified in the safety standard). In this example, the sealant (G) is applied so as to straddle the lens holding member 313 and the protective cover member (312d).

[0076] Sixth Embodiment In this embodiment, noise from the charging member 201 (charging roller in this example) that charges the photosensitive drum 1 is likely to affect the light emitting element substrate (311) and, in turn, the light emission of the light emitting elements 31-31.

[0077] In this regard, in this embodiment, the high-voltage member is the charging member 201 that charges the photosensitive drum 1, and the intervening member (312d) is interposed between the light-emitting element substrate (311) and the charging member 201.

[0078] In this configuration, it is possible to effectively prevent noise from the charging member 201 from affecting the light emitting element substrate (311) and, in turn, the light emission of the light emitting elements 31-31.

[0079] 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]

[0080] 1. Photosensitive drum (an example of an image carrier) 100 Image forming device 101 Image forming apparatus main body 2 Charger 201 Charging member (example of high voltage member) 201a surface 201b Rotation axis 202 Charging roller bearing 3 print head 301 Positioning part 302 Positioned part 3021 Arc-shaped part 31 Light-emitting element 311 Light emitting element panel (an example of a light emitting element substrate) 312d Protective member (an example of an intervening member) 313 Lens holding member 314 Fixing member 315 Main body member 315c1 curved section 316 Support member 317 Protruding part 32 Lens Array 400 Photosensitive drum unit 401 Housing 410 Dispenser 420 Ultraviolet irradiation device 430 Caulking agent application device 440 Roller pressure bonding device E Adhesive material F UV curing adhesive FL main frame G Caulking agent L Longitudinal direction L1 One side L2 other side M Width direction M1 One side M2 Other side N Optical axis direction N1 One side N2 other side S array direction X rotation axis direction X1 Front side X2 Rear side Y left / right direction Z vertical direction da spatial distance db spatial distance ea Creepage distance eb Creepage distance f Gap

Claims

1. A print head comprising: a light-emitting element substrate 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 lens holding member that holds the lens array, the print head being provided in an image forming apparatus that has a high-voltage member to which a predetermined high voltage is applied, the light-emitting element substrate being provided in proximity to the high-voltage member; a print head comprising an intervening member interposed between the light-emitting element substrate and the high-voltage member;

2. 10. The printhead of claim 1, the light-emitting element substrate is a film-shaped light-emitting element panel, the high-voltage member is located on either one side or the other side in a width direction perpendicular to an arrangement direction of the plurality of light-emitting elements, The print head is characterized in that the light-emitting element panel is provided extending toward either one of the high-voltage members in the width direction.

3. 3. The printhead of claim 2, a support member for supporting the light-emitting element panel; a curved portion that is curved so as to be convex toward the high-pressure member is provided at an end of the support member on the high-pressure member side, The print head is characterized in that the light-emitting element panel is provided along the curved portion of the support member.

4. 3. The printhead of claim 2, The print head according to claim 1, wherein the light-emitting element panel has a protruding portion that protrudes toward the high-voltage member beyond the lens holding member.

5. 5. The printhead of claim 4, The print head is characterized in that the interposing member is a protective cover member that covers the protruding portion of the light-emitting element panel.

6. 3. The printhead of claim 2, a support member for supporting the light-emitting element panel; a gap is provided between the light-emitting element panel supported by the support member and the lens holding member; The print head is characterized in that the gap is sealed with a sealant.

7. 10. The printhead of claim 1, The print head according to claim 1, wherein the interposing member is an insulating member.

8. 10. The printhead of claim 1, The print head is characterized in that the interposing member is a conductive member and is grounded.

9. 10. The printhead of claim 1, the high-voltage member is a charging member that charges the image carrier, The print head is characterized in that the intervening member is interposed between the light-emitting element substrate and the charging member.

10. An image forming apparatus comprising the print head according to any one of claims 1 to 9.

11. An image forming apparatus comprising: a print head including a light emitting element substrate 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 lens holding member that holds the lens array; and a high voltage member to which a predetermined high voltage is applied, wherein the light emitting element substrate is provided in proximity to the high voltage member, an image forming apparatus comprising: an intervening member interposed between the light-emitting element substrate and the high-voltage member;

Images