JP2002062407A - Image formation element array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation element array in which the number of parts is decreased to improve assemblability and warpage or twist is prevented. SOLUTION: The image formation element array 20 is composed of a transparent part 21 and an opaque part 22 integrated as an image formation element part. In the transparent part 21, two lens faces of the entrance face 21a in the light emitting element side and a exit face 21b in the scanning side of a photoreceptor or the like, and a prism face 21c to guide a beam L from the entrance face 21a to the exit side to obtain an erect image in the arrangement direction are formed as integrated into one body. The part where the opaque part 22 is formed corresponds to the part conventionally covered with a light shielding member to prevent rays from entering or exiting through a part except for the lens faces. The image formation element part is formed by adding an opaque member to a roughly molded product 30 made of the transparent member and putting the body into a die having an optical face form of high accuracy and molding it by heating or pressurizing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital copying machine,
The present invention relates to a digital writing optical system of a digital output device such as a page printer or a digital facsimile, and more particularly to an imaging element array used in a solid-state scanning writing system.

[0002]

2. Description of the Related Art In recent years,
With the miniaturization of digital output devices as described above, there is a demand for miniaturization of digital writing devices which are roughly classified into two types. One of the digital writing methods is an optical scanning method in which a light beam emitted from a semiconductor laser or the like is optically scanned by a polarizer and a light spot is formed by a scanning imaging lens, and the other is a light emitting element array (for example, an LED array).
This is a solid-state scanning method in which a light beam emitted from a light source is formed into a light spot by an imaging element array. In the optical scanning method, the light path length increases because light is scanned by an optical deflector, whereas in the solid-state scanning method, the optical path length can be extremely short, which is advantageous for miniaturization of the apparatus. In addition, there is an advantage that no mechanical driving parts are provided.

FIG. 1 schematically shows the structure of an imaging element array. 1A is a sectional view in the arrangement direction, and FIG. 1B is a sectional view in the orthogonal direction. The imaging element array shown in FIG. 1 is a roof prism lens array, and its basic configuration and operation will be described. Each of the imaging elements constituting the illustrated roof prism lens array 1 has two light emitting surfaces, ie, an incident surface 3a on the light emitting element surface side where the light emitting element array 2 is located and an emission surface 3b located on the scanned surface side which is the photoconductor 5 side. A lens surface and a prism surface 4 for guiding the light beam L from the incident surface 3a to the emission side to obtain an erect image in the arrangement direction are integrally formed. The entrance surface 3a and the exit surface 3b are formed at a substantially right angle. Light emitted from one point on the light emitting element surface enters the roof prism lens array 1 from the entrance surface 3a, and the optical axis is substantially perpendicular at the prism surface 4. The light is bent and reflected, exits from the exit surface 3b, and reaches the scanned surface of the photoconductor 5. Due to the image forming action between the incident surface 3a and the light emitting surface 3b and the image reversing action on the prism surface 4, the image of one point on the light emitting element surface is main-scanned to the corresponding one point on the scanned surface of the photoreceptor 5. Direction (array direction of light emitting element array and imaging element array)
Is tied upright.

FIG. 2 is a cross-sectional view corresponding to FIG. 1B, showing an example in which a light-blocking member 10 is disposed on the above-described imaging element array 1 in order to prevent light rays from entering and exiting from portions other than the lens surface. FIG. FIG. 3 shows a configuration of an imaging element array disclosed in Japanese Patent Application Laid-Open No. 10-153751 as another example in which a light shielding member is arranged in the imaging element array. In this example, 12 is a roof prism lens array, 13 is an aperture member, 14 is a roof prism lens, 15 is a light-entering-side light-collecting element, 16 is an image-forming-side light-collecting element, 17 is a roof prism, 18 Reference numerals 19 and 19 denote openings, which are configured by combining the roof prism lens array 12 and the aperture member 13 as a light shielding member.

[0005] By the way, as the definition of digital output devices becomes higher, the imaging element array used for the solid-state scanning system is required to have higher definition imaging performance.
As a means for solving this, a method of reducing the diameter of each imaging element has been proposed. However, since the width of the imaging element array in the arrangement (main scanning) direction needs to be equal to the width to be scanned, the smaller the diameter of the imaging element, the more likely it is that warpage or twisting occurs, and the spot diameter of the light spot There is also a problem of causing variations in light spots and displacement of light spots. Further, as the diameter of the imaging element is reduced, it is necessary to more strictly control the processing accuracy and the assembling accuracy of each member, which makes the manufacture of the digital writing device difficult. In addition, if the diameter of the imaging element constituting the imaging element array is reduced, the light-shielding member must be reduced in size and thickness inevitably, which causes problems such as deterioration in workability and assemblability, warpage, and twist.

In view of the above-mentioned conventional problems, an object of the present invention is to provide an imaging element array in which the number of parts is reduced, the assembling property is improved, and warpage and twisting are prevented.

[0007]

According to a first aspect of the present invention, there is provided an imaging element array in which a plurality of imaging elements are arrayed and integrally formed to achieve the above object. In an imaging element array of an erecting unit-magnification system in the direction, the optical axis of the imaging element is not parallel to the input optical axis and the output optical axis, and the optically transparent glass or synthetic resin Characterized by being integrally formed of opaque glass or synthetic resin.

According to a second aspect of the present invention, in the imaging element array, the opaque glass or the synthetic resin is formed integrally with the transparent glass or the synthetic resin when transferring the optical surface shape. .

Further, in the imaging element array according to the third aspect, the twist preventing member is integrated.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a sectional view showing an embodiment of the imaging element array according to the present invention. In the imaging element array 20 of the present embodiment, the imaging element portion is constituted by a transparent portion 21 and an opaque portion 22 which are integrally formed, and has a substantially triangular cross section as a whole.

The transparent portion 21 has an incident surface 21 on the light emitting element surface side.
a and a prism surface 21 for guiding a light beam L from the incident surface 21a to the emission side to obtain an erect image in the arrangement direction.
and c are integrally formed. The shape of each of these surfaces is the same as in the example shown in FIG.

The portion provided with the opaque portion 22 corresponds to the portion covered by the light shielding member 10 shown in FIG. That is, each of the vertexes of the substantially triangular cross-sectional shape and the vicinity thereof is formed so as to cover the transparent portion 21. In the illustrated embodiment, each opaque portion 22 has an L-shaped cross section, but it is a matter of course that the opaque portion 22 does not have to have this shape.

FIG. 5 is a cross-sectional view showing a method of forming the imaging element portion of the imaging element array 20 according to the embodiment of FIG. When transferring a high-precision optical surface shape to a molded product, a method is used in which an element that has been processed into a rough shape in advance is placed in a high-precision mold, and heat and pressure are applied to transfer the high-precision optical surface shape. Sometimes. The imaging element section of the imaging element array 20 according to the embodiment of FIG. 4 is molded by this method. That is, when the optical surface is transferred to a rough molded product 30 made of a transparent member as shown in FIG. 5A, an opaque member is added and placed in a mold (not shown), and the transparent member and the opaque member are separated. Are simultaneously heated to melt the opaque member, and are integrally formed with the transparent member as shown in FIG. In addition, by appropriately controlling the heating temperature of the opaque member, the opaque member can be prevented from being mixed into the transparent member, so that the optical performance is not reduced.

FIG. 6 is a sectional view showing another embodiment of the imaging element array according to the present invention. The basic configuration of the imaging element unit is the same as that of the previous embodiment, but the opaque portions 2 of both wings are used.
A concave portion is formed on each of the prism surfaces 21c of the second, and a torsion preventing member 40 is attached between the two concave portions in a bridge shape, and is formed integrally with the imaging element portion.

[0015]

As described above, the imaging element array according to the first aspect of the present invention prevents light rays from entering and exiting from portions other than the transparent member and the lens surface constituting the imaging element portion. Opaque member is formed integrally to reduce the number of parts by eliminating the light shielding member as a separate part, and it is not necessary to assemble the light shielding member, so that assemblability is improved and the number of assembling steps can be reduced. This has the effect.

In the imaging element array according to the second aspect, as described above, the portion which becomes an opaque member when the optical surface shape is transferred is integrally formed, so that in addition to the above-mentioned common effects, the work such as bonding and the like can be performed. In addition, operations such as positioning, adjustment, and the like can be omitted, and there is an effect that assemblability is further improved.

As described above, the imaging element array according to the third aspect is formed integrally with the torsion preventing member, so that in addition to the above-mentioned common effects, warpage and twist of the imaging element portion can be eliminated. It is possible to prevent variations in the spot diameter of the light spot and displacement of the light spot due to the imaging element portion,
In addition, since operations such as positioning and adjustment for eliminating the effects of warpage and torsion can be omitted, there is an effect that assembly becomes easy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (A) in the arrangement direction and a cross-sectional view (B) in a direction orthogonal to each other schematically showing the structure of an imaging element array.

FIG. 2 is a cross-sectional view corresponding to FIG. 1B showing a conventional example in which a light shielding member is arranged in an imaging element array.

FIG. 3 is a perspective view (A) showing another conventional example in which a light shielding member is arranged in an imaging element array, a perspective view (B) of the light shielding member, and an overall sectional view (C).

FIG. 4 is a sectional view showing an embodiment of an imaging element array according to the present invention.

FIG. 5 is a cross-sectional view illustrating a method of forming an imaging element portion of the imaging element array according to the embodiment of FIG.

FIG. 6 is a sectional view showing another embodiment of the imaging element array according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roof prism lens array 2 Light emitting element array 3a Incident surface 3b Outgoing surface 4 Prism surface 5 Photoreceptor 10 Light shielding member 12 Roof prism lens array 13 Aperture member 14 Roof prism lens 15 Light incident side light condensing element part 16 Imaging side light condensing Element part 17 Roof prism part 18, 19 Aperture 20 Imaging element array 21 Transparent part 21a Incident surface 21b Exit surface 21c Prism surface 22 Opaque part 30 Rough molded product 40 Twist preventing member L Light flux

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Claims (3)

[Claims] An imaging element array of an erecting equal-magnification system in an arrangement direction in which a plurality of imaging elements are arrayed and integrally formed, wherein an incident optical axis and an outgoing optical axis of the imaging element are provided. Are non-parallel, formed integrally with optically transparent glass or synthetic resin and opaque glass or synthetic resin. 2. The imaging element array according to claim 1, wherein said opaque glass or synthetic resin is formed integrally with said transparent glass or synthetic resin when transferring an optical surface shape. Image element array. 3. The imaging element array according to claim 1, wherein a twist preventing member is integrated.