JP2005047113A - Optical printer head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical printer head which has a high strength, is inexpensive and is superior in the workability. <P>SOLUTION: In the optical printer head, a housing 4 with a rod lens array 3 fixed thereto, and a base plate 5 are disposed above a head substrate 1 and below the head substrate, respectively. The head substrate 1 has many light emitting elements arranged in an array shape or in a staggering line shape in a main scanning direction. The base plate 5 is formed by press working of a metal flat sheet and consists of a long-shaped substrate mounting part 5a where the head substrate 1 is mounted, and leg parts 5b and 5c at both side faces in a longitudinal direction of the substrate mounting part. Moreover, the leg parts 5b and 5c are multilayer structures of a metal flat sheet with the metal flat sheet folded at the lower ends. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical printer head used as exposure means for an electrophotographic printer or the like.
[0002]
[Prior art]
Conventionally, an optical printer head such as an LED array head has been used as exposure means for an electrophotographic printer or the like.
[0003]
As shown in FIG. 3, the conventional optical printer head includes a head substrate 21 in which a plurality of light emitting element array chips 22 each having a plurality of light emitting elements arranged in a straight line in the main scanning direction are mounted in a line. The housing 24 has a rod lens array 23 attached thereto, and a base plate 25 formed by aluminum die casting.
[0004]
A housing 24 is disposed above the head substrate 21, and a base plate 25 is disposed below the head substrate 21. The head substrate 21, the housing 24, and the base plate 25 are sandwiched by, for example, a clip 26 having a U-shaped cross section. The structure was held integrally.
[0005]
Such an optical print head selectively emits a large number of light emitting elements provided on the upper surface of the light emitting element array chip 22 based on image data supplied from the outside, and the emitted light. Is supplied to the outside through the rod lens array 23.
[0006]
A photosensitive drum P such as a copying apparatus or a printing apparatus is disposed outside the optical print head, and light given to the outside through the rod lens array 23 is applied to the photosensitive drum P with a predetermined latent image. Will be formed. The latent image formed on the photosensitive drum P is then converted into a toner image through a process such as development, and a predetermined image is recorded on the recording paper by transferring and fixing the toner image on the recording paper. .
[0007]
[Patent Document 1]
JP-A-11-58820
[Problems to be solved by the invention]
By the way, in the conventional optical printer head described above, an aluminum extrusion-molded product and an aluminum die-cast product are used as the base plate as described above. Thus, extrusion molded products and die cast molded products lacked the versatility of processing and were expensive to manufacture.
[0009]
In addition, as an alternative, a pressed product obtained by pressing a metal flat plate into a U-shaped cross section is conceivable. Although such a base plate is advantageous in terms of cost, it is extremely strong at the legs. However, there is a problem in that it cannot be stably mounted when mounted on a copying apparatus or a printing apparatus.
[0010]
The present invention has been devised in view of the above-described drawbacks, and an object thereof is to provide an optical printer head having excellent strength, low cost, and excellent workability by using a base plate capable of obtaining strength.
[0011]
[Means for Solving the Problems]
The optical printer head of the present invention includes a housing in which a rod lens array is attached above a head substrate having a large number of light emitting elements arranged in a line or a staggered pattern in the main scanning direction, and a base plate below In each of the optical printer heads,
The base plate includes a long substrate mounting portion on which the head substrate formed by pressing a metal flat plate is mounted, and a pair of legs provided on both sides in the longitudinal direction of the long substrate mounting portion. And the leg portion has a multi-layer structure of a metal flat plate in which the metal flat plate is folded at the lower end thereof.
[0012]
Further, the folded metal flat plate tip of the leg portion extends upward from the long substrate mounting portion.
[0013]
According to the optical printer head of the present invention, a base plate formed by press molding a metal flat plate is used as the base plate. The configuration has a long substrate mounting portion on which the head substrate is mounted, and a pair of leg portions provided on both sides in the longitudinal direction of the long substrate mounting portion. The leg portion is folded at the lower end portion of the leg portion to have a multilayer structure in which metal flat plates are folded. That is, the leg portion can be processed relatively easily by pressing a metal flat plate, and the cost can be suppressed to half or less as compared with conventional aluminum extruded products and die cast products. Moreover, since the leg portion has a multilayer structure, bending strength comparable to that of a conventional base plate can be obtained.
[0014]
Further, the bent metal flat plate tip of the leg portion extends upward from the mounting surface of the elongated substrate mounting portion. The extension amount extends upward in a range not exceeding the thickness of the head substrate, for example, in the range of 0.5 to 1.0 mm. When mounting the head substrate or housing on the mounting surface of the long substrate mounting portion, a pair of metal flat plates protruding on both sides in the longitudinal direction serve as a guide for the mounting position of the head substrate and housing, so that a predetermined position A head substrate and a housing can be mounted on the head.
[0015]
Further, dust and dirt entering from the side surface of the head can be effectively blocked by the metal flat plate protruding upward from the mounting surface of the long substrate mounting portion. Therefore, it becomes easy to work, and the productivity of the optical printer head can be kept high.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
[0017]
FIG. 1 is a perspective view of an optical printer head according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the optical printer head of FIG. Reference numeral 1 denotes a head substrate, 2 denotes a light emitting element array chip, 3 denotes a rod lens array, 4 denotes a housing, and 5 denotes a base plate.
[0018]
The head substrate 1 has a long rectangular shape made of an insulating material such as a glass cloth base epoxy resin, glass, or ceramic, and a light emitting element array chip 2 is attached to the upper surface thereof. Although not shown, electrodes, driver ICs and the like are attached to each issuing element array chip 2.
[0019]
When the head substrate 1 is made of, for example, a glass cloth base epoxy resin, the glass cloth base formed using glass yarn is impregnated with a liquid epoxy resin and cured, and the head base 1 is formed into a long shape having a predetermined dimension. Produced by cutting.
[0020]
The plurality of light emitting element array chips 2 attached to the upper surface of the head substrate 1 are arranged in a line in the longitudinal direction (main scanning direction) of the head substrate 1, and each light emitting element array chip 2 is For example, it has a large number of light emitting elements arranged in a straight line in the main scanning direction at a density of 600 dpi (dot per inch).
[0021]
As the light-emitting element, for example, a light-emitting diode formed using a GaAlAs-based or GaAsP-based compound semiconductor is preferably used, and a pn junction is provided inside the light-emitting diode. When a predetermined power supply is supplied, electrons and holes are recombined near the pn junction, and the light emitting element emits light with a predetermined luminance.
[0022]
The light emitting element array chip 2 having such a light emitting diode employs a conventionally known semiconductor manufacturing technique, specifically, MOCVD (Metal Organic Chemical Vapor Deposition) method or the like, and converts the above compound semiconductor into single crystal silicon. The light emitting element array chip 2 formed by epitaxial growth on the upper surface of the wafer is placed at a predetermined position on the upper surface of the head substrate 1 and corresponds to a pad (not shown) provided on the light emitting element array chip 2. The light emitting element array chip 2 is mounted on the head substrate 1 by individually bonding the electrodes to each other with a fine metal wire or the like.
[0023]
A housing 4 made of a resin such as polycarbonate or liquid crystal polymer is disposed above the head substrate 1.
[0024]
The housing 4 has a band-shaped opening into which the rod lens array 3 is inserted, and a lower region of the housing 4 is brought into close contact with the upper surface of the head substrate 1 along the outer periphery of the head substrate 1. A sealed space is formed between 3 and the light emitting element array chip 2.
[0025]
The rod lens array 3 inserted into the opening of the housing 4 has a structure in which a large number of rod-shaped lenses arranged in a linear or zigzag manner are sandwiched between a pair of side plates. The light emitting element functions as an erecting equal-magnification type optical system that irradiates and forms an image with the same magnification on the photoreceptor P disposed above the rod lens array 3.
[0026]
When the housing 4 is made of a plastic material such as a liquid crystal polymer, it is manufactured by processing it into a predetermined shape by a conventionally known injection molding method, and the rod lens array 3 is installed in the opening of the obtained housing 4. The rod lens array 3 is attached and fixed to the housing 4 by being inserted and bonded together.
[0027]
Further, a base plate 5 formed by pressing a metal flat plate material is disposed below the head substrate 1. The base plate 5 has a U-shaped longitudinal section having a long substrate mounting portion 5a and legs 5b and 5c extending downward from the longitudinal side portions.
[0028]
The base plate 5 is formed, for example, by pressing a metal flat plate material such as iron or SUS that has been surface galvanized so that the cross-sectional shape is substantially U-shaped. The leg portions 5b and 5c are bent downward at both ends in the longitudinal direction of the elongated substrate mounting portion 5a, and further folded back at the lower ends of the leg portions 5b and 5c. 5e extends above the mounting surface of the long substrate mounting portion 5a. That is, the leg portions 5b and 5c have a multilayer structure in which at least two metal flat plates overlap each other.
[0029]
And the front-end | tips 5d and 5e of a metal flat plate are extended upwards in the range which does not exceed the thickness of the head board | substrate 1 rather than the mounting surface of the elongate board | substrate mounting part 5a. Specifically, since the thickness of the entire head substrate 1 is 0.6 to 1.4 mm, the tips 5d and 5e of the metal flat plate are located above the mounting surface of the long substrate mounting portion 5a from the head substrate 1. It extends in the range of 0.5 to 1.0 mm so as not to protrude.
[0030]
The head substrate 1 is arranged on the mounting surface of the long substrate mounting portion 5 a of the base plate 5, and further, for example, between the both end surfaces of the head substrate 1 and the metal flat plate that is a part of the leg portion 5. A part of the housing 4 is fitted and mounted. At this time, if the protruding amounts of the metal flat plate tips 5d and 5e are 0.5 mm or less, it becomes difficult to stably hold the head substrate 1 on the mounting surface of the long substrate mounting portion 5a. When the thickness exceeds 1 and exceeds 1.0 mm, for example, when the head substrate 1 is placed between the pair of metal flat plates on the mounting surface of the long substrate mounting portion 5a, the mounting trouble is reversed. It also becomes a hindrance when correcting the position after mounting, and when the head substrate 1 is closely fixed to the mounting surface of the long substrate mounting portion 5a, the contact work becomes very difficult, Workability will be reduced.
[0031]
The housing 4 and the base plate 5 are held and fixed in addition to being fitted between the head substrate 1 and the metal flat plate as described above, and a part of the housing is engaged with a part of the legs 5b and 5c. A function of stopping may be provided, and both may be mechanically fixed.
[0032]
Thus, when the head substrate 1 and the housing 4 are mounted on the long substrate mounting portion 5a of the base plate 5, the head substrate 1 and the housing 4 are sandwiched between a pair of metal flat plates folded from the leg portions 5b and 5c. Even if warpage occurs in the housing 4 of the plastic molded product, it is corrected by this pair of metal flat plates. Thereby, the light emitted from the light emitting element array chip 2 can accurately reach the photosensitive member P through the rod lens array 3.
[0033]
Further, the mounting surface of the long substrate mounting portion 5a is concealed on the side surface in the longitudinal direction by the metal flat plate which is a part of the legs 5b and 5c, so that it is mounted on the long substrate mounting portion 5a. It is also possible to prevent dust and dust from flowing into the head substrate 1 to be used.
[0034]
Thus, in the optical printer head described above, the legs 5b and 5c of the base plate 5 have a multi-layer structure by folding back a metal flat plate. It was confirmed. In addition, the base plate can be formed by pressing a metal flat plate, and can be very inexpensive.
[0035]
Further, the front end portions 5d and 5e of the folded structure of the metal flat plate constituting the leg portion extend above the long substrate mounting portion 5a, and the pair of extended metal flat plate and the long substrate mounting are provided. Since the head substrate 1 and the housing 4 can be mounted on the basis of the portion 5a, the head substrate 1 and the housing 4 can be accurately aligned. That is, the positioning of the head substrate 1 and the housing 4 itself can of course correct, for example, the warping of the housing 4, and an optical printer head capable of accurately forming a predetermined latent image on the photosensitive drum P. It becomes.
[0036]
In addition, this invention is not limited to the above-mentioned form, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
[0037]
In the above embodiment, the LED head has been described as an example. However, the present invention is applicable to other optical printer heads such as an EL head, a plasma dot head, a liquid crystal shutter head, a fluorescent head, and a PLZT. is there.
[0038]
【The invention's effect】
According to the optical printer head of the present invention, the base plate is formed by pressing a metal flat plate, and is provided on the long substrate mounting portion on which the head substrate is mounted, and on both sides in the longitudinal direction of the long substrate mounting portion. The leg portion has a multilayer structure in which a metal flat plate is folded back at the lower end portion. Thereby, it is not inferior in strength to the conventional base plate, and can be formed by a very simple processing such as press processing, and the optical print head itself can be made very inexpensive.
[0039]
In addition, since the tip of the multi-layered metal flat plate that constitutes the leg protrudes above the mounting surface of the long substrate mounting part, the head substrate can be mounted at a predetermined position, It is possible to prevent the inflow of dust and debris into the water, making the work easier and maintaining the productivity of the optical printer head high.
[Brief description of the drawings]
FIG. 1 is a perspective view of an optical printer head of the present invention.
2 is a cross-sectional view of the optical printer head of FIG.
FIG. 3 is a cross-sectional view of a conventional optical printer head.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Head substrate 2 ... Light emitting element array chip 3 ... Rod lens array 4 ... Housing 5 ... Base plate 5a ... Elongated board | substrate mounting part 5b, 5c ... Leg part 5d 5e ... tip T ... multilayer structure

Claims (2)

An optical printer head having a housing in which a rod lens array is mounted above a head substrate having a large number of light emitting elements arranged in a line or a staggered pattern in the main scanning direction, and a base plate disposed below. In
The base plate is formed by pressing a metal flat plate, and a long substrate mounting portion on which the head substrate is mounted, and a pair of leg portions provided on both sides in the longitudinal direction of the long substrate mounting portion. An optical printer head characterized in that the leg portion has a multi-layered structure of metal flat plates in which the metal flat plate is folded at the lower end thereof. 2. The optical printer head according to claim 1, wherein a tip end of the metal flat plate of the leg portion extends upward from a mounting surface of the elongated substrate mounting portion.

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