JP5246054B2 - Printhead manufacturing method - Google Patents

Description

  The present invention relates to a printhead mold, a printhead, and the like for forming a printhead used in an image forming apparatus such as a copying machine.

  As shown in FIGS. 10 and 11, conventionally, in order to form an electrostatic latent image of an image on an electrostatic latent image carrier 225 such as a photoconductor of an image forming apparatus, a light emitting element array 204 and a lens array 203 are provided. A print head 201 as a main component is used.

  The print head 201 includes a printed board 211 on which a light emitting element array 204 including light emitting elements such as a plurality of light emitting diodes (LEDs) is mounted (fixed), a base plate 202 to which the printed board 211 is fixed, and a lens array 203. There is a cover 205 that is fixed to the base plate 202 so that the light emitting element of the light emitting element array 204 and the lens array 203 face each other (for example, see Patent Documents 1 to 3).

  As shown in FIG. 11, the print head 201 having such a configuration emits light from a light emitting point of a light emitting element array 204 fixed to the surface of a printed circuit board 205 with an adhesive or the like. The distance is set to be the conjugate length TC.

  The conjugate length TC includes a distance L from the light emitting point to the lower surface (one lens surface) of the lens array 203, a distance L from the upper surface (the other lens surface) of the lens array 203 to the imaging point, and the lens array 203. And a relationship of TC = T + 2L is established. The imaging point is a focal position where the light emitted from the light emitting point is converged (condensed) by the lens array 203.

  In such a print head 201, the cover 205 is manufactured by injection molding using resin for the purpose of reducing the manufacturing cost. At this time, the parting line surface of the movable and fixed mold is used as the reference surface 206 of the cover 205, and a runner and a gate for injecting molten resin into the cavity for molding the cover 205 are provided on the parting line surface. It is common. Here, the parting line surface refers to a split surface of a movable type and a fixed type.

JP 2005-193638 A JP 2006-289843 A JP 2007-331182 A

  However, since the gate cut trace 207 remains on the cover 205 even if the gate is cut, the gate cut trace 207 may protrude with respect to the reference plane 206.

  In this case, when the print head is manufactured by fixing the cover 205 to the base plate 202, the one end side with the gate is lifted (dimension T), as shown in FIG. 12, and is thus fixed to the base plate 202 via the printed board 211. The line formed by connecting the light emitting points of the light emitting element array 204 and the lens array 203 are not parallel. For this reason, there is a problem that an image forming line formed by connecting the image forming points of the print head 201 is inclined.

  Further, when the print head 201 is mounted on the image forming apparatus, the electrostatic latent image carrier 225 and the imaging line are not parallel to each other, and there is a problem that the image quality is deteriorated.

  The present invention has been made to solve the above-described problem, and the gate for injecting the molten resin into the cavity is formed by a fixed mold and a movable mold different from the parting line surface. An object of the present invention is to provide an inexpensive print head that has a simple configuration and a line formed by connecting light emitting points and a lens array in parallel.

(First invention)
According to a first aspect of the present invention, there is provided a method for manufacturing a printhead, comprising: a long molded product formed between a fixed mold and a movable mold that are separable on a dividing surface and having a reference surface on the same plane as the dividing surface. In order to form a long cavity and a long through-hole formed in the long molded product formed by the cavity, a protrusion protruding from the fixed mold or the movable mold in a direction perpendicular to the dividing surface. And a gate formed by a surface of the fixed mold and the movable mold provided on one end in the longitudinal direction of the cavity and on a plane different from the reference plane, and on the same plane as the reference plane The long mold obtained by preparing a mold including a runner formed by the surface of the fixed mold or the movable mold, injecting molten resin into the cavity from the gate, and cooling and solidifying the molten resin The through hole of the molded product The reference surface of the elongated molded product is brought into contact with the surface of the base plate to which the lens array is fixed and the printed circuit board on which the plurality of light emitting element arrays are mounted is opposed to the lens array and the light emitting element array. To fix .

With such a configuration, as a result of the operator cutting the gate portion using a nipper or the like, even when a part of the gate portion remains in the long molded product (cover), when the reference surface of the cover is brought into contact with the base plate, Due to a part of the gate portion, there is no problem that the line formed by connecting the light emitting points and the lens array are not parallel . In other words, the first invention can provide a print head manufacturing method in which a part (remaining part) of the gate portion attached to the long molded product does not affect the optical axis of the print head .
Here, the gate portion refers to a portion where the molten resin in the gate of the long molded product gate is cooled and solidified and connected to the long molded product, and is not functionally necessary for the long molded product. Cutting the gate portion is generally referred to as gate cut, but the term gate portion is used to express the terminology for the long molded product gate.

According to the present invention, it is possible to provide a print head in which a part of the gate attached to the molded product does not affect the optical axis of the print head .

It is sectional drawing of the metal mold | die for long molded articles. It is the elements on larger scale of sectional drawing of the gate vicinity of the metal mold | die for long molded articles. It is a perspective view of the cover (with a gate part and a runner part) of a print head. It is a perspective view of the cover (with a gate part and a runner part) of a print head. It is a perspective view of the cover of a print head. 2 is a plan view of a print head. FIG. It is a perspective view of a print head. FIG. 3 is a cross-sectional view of a print head. It is a top view of a printed circuit board. FIG. 4 is a diagram illustrating a mounting state of a print head. FIG. 3 is a cross-sectional view of a print head. It is a perspective view of a print head. 1 is a diagram illustrating an overall configuration of an image forming apparatus. It is sectional drawing of the metal mold | die for long molded articles.

  Hereinafter, the present invention will be described in detail using examples.

(Mold for long molded products)
FIG. 1 shows a cross section of the long molded product mold according to the present invention. FIG. 2 is a partially enlarged view of the vicinity of the gate 32 in FIG. In FIG. 1, the convex portion 38 of the movable mold 35 is inserted into the cavity 31, and this forms a long through hole for fixing the lens array to the molded product molded inside the cavity 31. The cavity 31 is a portion extending from the right side of the page indicated by the dotted line to the fixed mold 34.

  As shown in FIG. 1, a long mold 31 has a long cavity 31 formed between a fixed mold 34 and a movable mold 35 that can be separated by a parting line surface 36. A gate 32 is provided at one end in the longitudinal direction (Y-axis direction). The gate 32 refers to an injection port for injecting molten resin flowing through the runner 33 into the cavity 31.

  The lower surface of the cover as a long molded product molded inside the cavity 31 is a reference surface, and this reference surface is formed by one surface 37 of the cavity 31 that is on the same plane as the parting line surface 36. . The direction in which the convex portion 38 protrudes from the movable die 35 into the cavity 31 (Z-axis direction) and the parting line surface 36 are in a right angle relationship with each other.

  The gate 32 is formed by a plurality of surfaces of the fixed die 34 and the movable die 35, but none of the surfaces is on the same plane as the parting line surface 36 described above (what is the parting line surface 36? On different planes). In other words, the gate 32 is formed by a gap between the concave portion formed in the fixed die 34 and the convex portion formed in the movable die 35, but the surface constituting the concave portion and the surface constituting the convex portion are parting. It is not on the same plane as the line surface 36.

(Long molded product)
Next, a cover as a long molded product molded by the above-described long molded product mold 30 will be described.
3 is a perspective view of a cover with a runner and a gate portion, FIG. 4 is an enlarged perspective view of the gate portion in FIG. 3, and FIG. 5 is a perspective view of the cover after the gate portion is cut.

  The cover 41 shown in FIG. 3 injects a molten resin in which LCP (Liquid Crystal Polymer) is melted into the cavity 31 of the mold 30 shown in FIGS. 1 and 2, and fills the cavity 31 with the molten resin. After that, the molten resin can be cooled and solidified by flowing cooling water or the like through the long molded article mold 30.

  In the cover 41, as described above, molten resin is injected into the cavity 31 from the gate 32 constituted by the surfaces of the fixed mold 34 and the movable mold 35 different from the parting line surface 36. For this reason, when this molten resin is cooled and solidified, as shown in FIGS. 3 and 4, the cover 41 with the gate portion 46 having the surface 43 that is one step lower than the surface 45 of the runner portion 44 and the reference surface 42 is elongated. The molded product mold 30 can be taken out. The surface 45 and the reference surface 42 are surfaces that are on the same plane as the parting line surface 36.

  For this reason, when the gate part 46 is cut using a nipper or the like, the cover 41 can be obtained as shown in FIG. Since the gate cut mark 47 obtained by cutting the gate portion 46 is at a position away from the reference surface 42 of the cover 41, even if the reference surface 42 is fixed in contact with the base plate, as will be described later, FIG. As shown, the optical axis does not shift.

  The cover 41 is provided with a through hole 48 that is long in the Z-axis direction perpendicular to the reference surface 42.

(Print head)
Next, a print head using the above-described long molded product (cover) will be described with reference to FIGS. 8 is a cross-sectional view taken along the line AA in FIG.
As shown in FIGS. 6 to 8, the print head 1 includes a cover 41 in which a lens array 3 in which a plurality of rod lenses 6 are arranged and arranged is inserted into a through hole 48 and fixed with an adhesive or the like, and a plurality of light emitting element arrays. 4 includes a printed circuit board 5 to which 4 is fixed, and a base plate 7 to which the printed circuit board 5 is fixed. The reference surface 42 of the cover 41 is in contact with the surface of the base plate 7 and fixed with an adhesive or the like so that one lens surface of the lens array 3 and the light emitting element array 4 face each other.

  As shown in FIGS. 8 and 9, for example, 58 light emitting element arrays 4 are fixed to the print head 1 with an adhesive or the like with high precision so as to be parallel to the axial direction of the photosensitive drum. Note that the light emitting element arrays 4 are alternately arranged in a staggered pattern so that each light emitting element array 4 is continuously arranged at the connection portion at the end boundary of the light emitting element array 4. For example, there are 128 light emitting points (LEDs) per array.

  As shown in FIG. 8, the print head 1 having such a configuration has a light emitting point (LED) of the light emitting element array 4 fixed on the surface of the printed circuit board 5 using an adhesive or the like to emit light. The distance to the imaging point is set to be the conjugate length TC. Since this is the same configuration as the prior art, a description thereof will be omitted.

  In the print head 1 according to the present invention, as shown in FIG. 7, the gate cut trace 47 of the cover 41 is located away from the reference plane 42 in the Z-axis direction. Even if there is, the problem as shown in FIG. 12 does not occur when the reference surface 42 is brought into contact with the surface of the base plate 7.

(Image forming device)
As shown in FIG. 13, the image forming apparatus according to the present invention is a so-called tandem digital color printer 131, and an image forming process unit 110 that forms an image corresponding to image data of each color, and an image forming process unit 110. And an image processing unit 140 that performs predetermined image processing on the image data received from the personal computer 102 or the image reading apparatus 103.

  The image forming process unit 110 includes four image forming units 111Y, 111M, 111C, and 111K that are arranged in parallel at a predetermined interval.

  Each of these image forming units 111Y, 111M, 111C, and 111K forms a latent image on the photosensitive drum 25 as an image carrier that carries a toner image, and the surface of the photosensitive drum 25. A charging device 113 that is uniformly charged at a predetermined potential, a print head 1 as an exposure device that exposes the photosensitive drum 25 whose surface is charged by the charging device 113, and an electrostatic latent image obtained by the print head 1 A developing device 115 for developing and a cleaner (blade) 116 for cleaning the surface of the photosensitive drum 25 after transfer are provided.

  Further, a density detection circuit 117 that detects the toner image density of a test patch (density sample) formed on the photosensitive drum 25 is provided in the vicinity of the downstream side of the developing device 115 so as to face the photosensitive drum 25. It has been. The density detection circuit 117 is connected to the control unit 130 and outputs a toner image density detection value.

  Here, the image forming units 111Y, 111M, 111C, and 111K are configured in substantially the same manner except for the toner stored in the developing device 115. The image forming units 111Y, 111M, 111C, and 111K form yellow (Y), magenta (M), cyan (C), and black (K) toner images, respectively.

  In addition, the image forming process unit 110 includes an intermediate transfer belt 121 onto which the toner images of the respective colors formed on the photosensitive drums 25 of the image forming units 111Y, 111M, 111C, and 111K are transferred, and the image forming units 111Y. , 111M, 111C, and 111K toner images are sequentially transferred (primary transfer) to the intermediate transfer belt 121, and a primary transfer roll 122 as a primary transfer charging device and a superimposed toner image transferred onto the intermediate transfer belt 121 are recorded. A secondary transfer roll 123 as a secondary transfer charging device that performs batch transfer (secondary transfer) onto a paper P that is a material (recording paper), and a fixing device 125 that fixes the secondary transferred image onto the paper P. I have.

  The image forming process unit 110 performs an image forming operation based on a control signal such as a synchronization signal supplied from the control unit 130. At that time, image data input from the personal computer 102 or the image reading device 103 is subjected to image processing by the image processing unit 140 and supplied to each of the image forming units 111Y, 111M, 111C, and 111K via the interface. .

  For example, in the yellow image forming unit 111Y, the surface of the photosensitive drum 25 uniformly charged at a predetermined potential by the charging device 113 emits light based on the image data obtained from the image processing unit 140. The electrostatic latent image is formed on the photosensitive drum 25 by being exposed by the print head 1.

  This electrostatic latent image is developed by the developing device 115, and a yellow toner image is formed on the photosensitive drum 25. Similarly, magenta, cyan, and black toner images are formed on the respective photosensitive drums 25 of the image forming units 111M, 111C, and 111K.

  The color toner images formed on the respective photosensitive drums 25 of the image forming units 111Y, 111M, 111C, and 111K are sequentially transferred by the primary transfer roll 122 onto the intermediate transfer belt 121 that rotates in the direction of arrow A in FIG. A toner image superimposed on the intermediate transfer belt 121 is formed by electrostatic attraction.

  The superimposed toner image is conveyed to an area (secondary transfer portion) where the secondary transfer roll 123 is disposed as the intermediate transfer belt 121 rotates. When the superimposed toner image is conveyed to the secondary transfer unit, the paper P is supplied to the secondary transfer unit in accordance with the timing at which the toner image is conveyed to the secondary transfer unit.

  Then, the superimposed toner images are collectively electrostatically transferred onto the conveyed paper P by the transfer electric field formed by the secondary transfer roll 123 in the secondary transfer portion. Thereafter, the sheet P on which the superimposed toner image is electrostatically transferred is peeled off from the intermediate transfer belt 121 and conveyed to the fixing device 125 by the conveying belt 124.

  The unfixed toner image on the paper P conveyed to the fixing device 125 is fixed on the paper P by being subjected to fixing processing by heat and pressure by the fixing device 125. Then, the paper P on which the fixed image is formed is conveyed to a paper discharge placement unit (not shown) provided in the discharge unit of the digital color printer 131.

  Since the above-described image forming apparatus uses the print head 1 using the cover 41 formed by the above-described long molded product mold 30, there is no influence of the gate cut trace 47 on the optical axis. For this reason, a high quality image can be formed.

Another embodiment of the long molded product mold according to the present invention will be described with reference to FIG.
In FIG. 14, the convex portion 58 of the fixed mold 54 is inserted into the cavity 31, and this is a long through hole for fixing the lens array to a long molded product molded inside the cavity 31. A portion from the left side of the paper surface to the movable die 55 is a cavity 31 for forming.
To simplify the description, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The main difference between the second embodiment and the first embodiment is that the gate 32 and the runner 33 are formed on the movable die 55.
That is, as shown in FIG. 14, the long mold 31 has a long cavity 31 formed between a fixed mold 54 and a movable mold 55 that can be separated by the parting line surface 36. A gate 32 is provided at one end of 31 in the longitudinal direction (Y-axis direction).

  The lower surface of the cover as a long molded product molded inside the cavity 31 is a reference surface, and this reference surface is formed by one surface 37 of the cavity 31 that is on the same plane as the parting line surface 36. . The direction in which the protrusions 58 protrude from the fixed mold 54 into the cavity 31 (Z-axis direction) and the parting line surface 36 are perpendicular to each other.

The gate 32 is formed from a plurality of surfaces of the fixed die 54 and the movable die 55, but none of the surfaces is on the same plane as the parting line surface 36 described above (what is the parting line surface 36? On different planes).
The cover 41 can be molded even with the long molded product mold 50 having such a configuration.

  The above-described embodiments have been illustrated for the purpose of explanation, and the present invention is not limited thereto. Those skilled in the art will recognize from the claims, the detailed description of the invention, and the drawings. Modifications and additions can be made without departing from the technical idea of the present invention.

  8 and 9 show the light emitting element array 4 fixed in a zigzag shape, the light emitting element array 4 may be fixed in a straight line.

  The present invention is applied to a print head used in a copying machine, a printer, or the like.

DESCRIPTION OF SYMBOLS 1 Print head 3 Lens array 4 Light emitting element array 5 Printed circuit board 7 Base plate 30 Mold 31 for a long molded product Cavity 32 Gate 34 Fixed mold 35 Movable mold 36 Parting line surface 38 Convex part 41 Long molded product (cover)
42 Reference plane

Claims (1)

A long cavity that is formed between a fixed mold and a movable mold that are separable by a dividing surface, and that forms a long molded product having a reference surface on the same plane as the dividing surface;
In order to form a long through hole for the long molded product formed by the cavity, a convex portion protruding from the fixed mold or the movable mold in a direction perpendicular to the dividing surface;
A gate provided at one end in the longitudinal direction of the cavity and formed by the surfaces of the fixed mold and the movable mold on a plane different from the reference plane;
A runner formed by the surface of the fixed mold or the movable mold on the same plane as the reference surface;
Prepare a mold with
Injecting molten resin from the gate into the cavity,
A lens array is fixed to the through hole of the long molded product obtained by cooling and solidifying the molten resin,
Manufacture of a print head in which the reference surface of the long molded product is fixed in contact with a surface of a base plate on which a printed circuit board on which a plurality of light emitting element arrays are mounted is fixed, so that the lens array and the light emitting element array face each other. Method.

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