JPH1082972A - Image forming element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming element which prevents the stray light of a luminous flux deviated from an optical axis from affecting an adjacent image forming system. SOLUTION: A part or the whole of the ridge lines of a roof mirror array is formed of a plane or polyhedron or curved surface so as to be able to adjust the direction of the stray light and the degree of scattering as a specular reflection preventive mean at the ridge line parts 2a of the roof mirror array. As a result, the reflection of the stray light at the ridge lines is prevented. When the plane is formed of the polyhedron, the control of the reflected rays of the stray light is possible and if the curved surface is used, the degree of the scattering of the stray light is made adjustable by the bending degree of the curved surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device, and more particularly, to an optical system used in a reading optical system used in a copying machine or a facsimile or a reading scanner used in combination of a CCD line sensor and a 1: 1 sensor. The present invention relates to an imaging element suitable for use in a system or an optical system used for an optical print head or a self-scanning optical print head.

[0002]

2. Description of the Related Art FIG. 6 is a view showing the construction of a main part of an optical system for forming a real-size real image according to the prior art. In FIG. A mirror, 14 is a document surface, 15 is an image forming surface, and A is an image reading position.

The roof mirror lens is an "optical system for forming a real-size real image", has a configuration as shown in FIG. 6, and sets a reading position A at a finite slit height position not on the optical axis. The reflected light from the reading position A is converted into substantially parallel light by the condenser lens 11, then turned back by the roof mirror 12, passed through the condenser lens 11 again, and forms an image on the image plane 15. is there.

As disclosed in Japanese Patent Publication No. 61-2929, for example, a prism lens array has a lens array and a roof mirror array integrated with each other. The reading position is set at the slit height position, and after the reflected light passes through the lens surface, it is reflected by the roof prism twice, passes through the lens surface again, and forms an image at a conjugate position.

[0005] The roof mirror lens array is an "optical system for forming a real-size real image".
Various types of lenses, such as those disclosed in Japanese Patent Application Publication No. 26-26, are known. A "lens array" in which a series of lenses equivalent to an optical system are arranged in a line, and a lens array in this lens array A roof mirror array in which a series of roof mirrors having ridges perpendicular to the direction and the optical axis of the lens are arrayed in a one-to-one correspondence with the individual lenses in the lens array; A "stop member" is provided between the mirror array and separates the imaging system of the lens and the roof mirror from each other. I have.

[0006]

In the above-described configuration according to the prior art, an arbitrary lens in the lens array constitutes an "imaging system" with a corresponding roof mirror, and each aperture of the aperture member is It is necessary to be positioned corresponding to each of these imaging systems and to optically separate the imaging systems from each other.

That is, in the above-described configuration, it is necessary to reduce the distance between the lens array and the roof mirror array or to narrow the aperture of the aperture member in order to allow the same lens to pass therethrough.

In FIG. 6, an optical path separating mirror 13 is a strip-shaped flat mirror which is long in a direction perpendicular to the drawing, and is disposed at an angle of 45 ° with respect to the “surface of the lens array 11 that shares the optical axis of each lens”. Has been established.

However, as described above, the roof mirror lens according to the prior art has a lens and a roof mirror so that an image-forming light beam passes through the same lens twice so that an off-axis light beam does not leak. Since the lens must be installed close to the lens and the thickness of the lens cannot be increased, the position of the image height can be restricted. Further, when the aperture is narrowed by narrowing or raising the aperture member, the light flux from the adjacent imaging system can be cut, but there is a problem that the light amount loss near the optical axis increases.

FIG. 7 is a diagram showing a main part of an image forming element according to the prior art, in which 21 is a lens array, 22 is a roof mirror array, and 22a is a roof mirror array array optical axis. The ridge between them, L ', is the ray.

The roof mirror lens array comprises a lens array 21 and a roof mirror array 22 in which the angle between two reflecting surfaces is 90 degrees. There is a disadvantage that the light beam obliquely incident on the lens is emitted from the imaging system of the adjacent roof mirror lens array.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in an imaging element array in which imaging elements are arranged in a line, stray light of a light beam deviating from the optical axis affects an adjacent imaging system. The purpose of the present invention is to provide an imaging element which is less affected.

[0013]

According to a first aspect of the present invention, there is provided a light-collecting element array in which a plurality of optically-equivalent light-collecting elements are arranged in a line, And a roof mirror array in which a plurality of roof mirrors equivalent to each other are arranged in a line, wherein the optical axis of each of the condensing elements and the ridge line of each roof mirror intersect. In the image element, a light beam incident from at least one light-collecting element and reflected by a roof mirror corresponding to the light-collecting element is emitted from an adjacent imaging system to at least a part of a ridge between the optical axes of the roof mirror array. Characterized by having a regular reflection preventing means for reducing the amount of luminous flux generated, which is capable of cutting stray light and increasing the degree of freedom of the positions of the lens array and the roof mirror array. Is

According to a second aspect of the present invention, in the first aspect of the present invention, the specular reflection preventing means has a shape in which a ridge between the optical axes of the roof mirror array is flat, polyhedral, or curved. This makes it possible to reduce the influence of stray light.

According to a third aspect of the present invention, in the first aspect of the present invention, the regular reflection preventing means is a rough surface having an uneven surface, and the regular reflection preventing means is easily provided. It is something that can be done.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the regular reflection preventing means is a light absorbing member, and a high-quality image less affected by stray light can be obtained. It is made possible.

According to a fifth aspect of the present invention, there is provided a light-collecting element array in which a plurality of optically equivalent light-collecting elements are arranged in a line, and an angle formed by two reflecting surfaces corresponding to the respective light-collecting elements. 90
And a roof prism array in which a plurality of optically equivalent roof prisms are arranged in a row, wherein an optical axis of each of the light condensing elements intersects a ridge line of each of the roof prisms. In the imaging elements arranged so that the light beams incident on at least a part of the valley between the optical axes of the roof prism array are reflected from the roof prism corresponding to the light collecting element and incident on the focusing element. The product is characterized by having a regular reflection preventing means comprising a transmission member having a refractive index substantially equal to the refractive index of the roof prism array for reducing a light beam emitted from an adjacent imaging system. It is possible to make it.

According to a sixth aspect of the present invention, a plurality of optically equivalent roof prisms having an angle of 90 degrees between the two reflecting surfaces are arranged in a line in a direction orthogonal to the ridge line of each roof prism. An image forming element in which a plurality of light-condensing elements corresponding to the respective roof prisms and optically equivalent to the roof prism array are integrally disposed on a light beam incident side and a light beam output side of each roof prism. In an imaging element arranged so that a ridge line of each roof prism and an optical axis of each light condensing element corresponding to each roof prism intersect, a valley between the roof prism array array optical axes is formed. At least a part of the roof prism array for reducing a light beam incident from a certain light condensing element and reflected by a roof prism corresponding to the light condensing element and emitted from an adjacent imaging system. Which was characterized by having a regular reflection preventing means consisting transmitting member having substantially the same refractive index as Oriritsu suppress the loss of light, in which to be able to make commercialization more easily.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing a main part of an image forming element according to an embodiment of the present invention. In FIG. 1, 1 is a lens array, 2 is a roof mirror array, and 2a is a roof mirror. The ridge between the optical axes of the array, L, is a light ray.

FIG. 1 (A), FIG.
As shown in (B), the ridge 2a between the optical axes of the roof mirror array is used as anti-reflection means so that the stray light and the degree of scattering can be adjusted. A part or the whole of the ridge 2a is constituted by a plane, a polyhedron, or a curved surface, thereby preventing stray light from being reflected at the ridge between the arrayed optical axes. (Not shown), the reflected light of the stray light can be controlled. As shown in FIG. 1B, when a curved surface is used, the degree of scattering of the stray light depends on the degree of curvature of the curved surface. Can be adjusted, and a desired image quality can be obtained.

Edge 2 between the optical axes of the roof mirror array
By providing the regular reflection preventing means in a, it is possible to suppress the generation of stray light, and it is not necessary to reduce the stray light by bringing the lens and the mirror closer to each other, thereby increasing the degree of freedom in optical design. In addition, the method of providing an aperture on the lens surface, which is another means, reduces the overall light amount. However, according to the present invention, since a stray light generating portion that does not affect image quality is cut, high quality is achieved. Image quality can be obtained.

FIG. 2 is a view showing the construction of a main part for explaining another embodiment of the imaging element according to the present invention. In the drawing, reference numeral 2b denotes a roughened surface, and other portions having the same functions as those in FIG. Are denoted by the same reference numerals as in FIG.

According to a third aspect of the present invention, as shown in FIG.
Rough surface 2 on ridge 2a between optical axes of roof mirror array
By providing b, it is possible to prevent stray reflection and scatter stray light to capture high-quality image quality. It is easy to roughen the roof mirror, so it is easy to take measures. It is made possible.

FIG. 3 is a diagram showing the construction of a main part of another embodiment of the imaging device according to the present invention. In FIG. 3, reference numeral 2c denotes a light absorbing member, and the other operations are the same as those in FIG. 1 or FIG. The same reference numerals as those in FIG. 1 or FIG.

According to the invention of claim 4, as shown in FIG.
Unlike the roughened surface 2b of the embodiment shown in FIG. 2, the light absorbing member 2c is provided at the ridge 2a between the optical axes of the roof mirror array, so that stray light is not generated as scattered light. It is possible to capture high-quality image with high contrast.

FIG. 4 is a view showing the construction of a main part of another embodiment of the imaging device according to the present invention. In FIG. 4, reference numeral 3 denotes a roof prism array, and 3a denotes a valley between optical axes of the roof prism array. Reference numeral 3b denotes a transmission member, and the other portions having the same functions as those in FIGS. 1 to 3 are denoted by the same reference numerals as those in FIGS.

According to a fifth aspect of the present invention, as shown in FIG.
The roof prism array 3 itself is processed by applying an appropriate amount of a transparent member 3b having a refractive index close to the refractive index of the roof prism array to the valley 3a between the optical axes of the roof prism array so that regular reflection does not occur. There is no need for this, correction is easy, and effective stray light removal can be performed.

FIG. 5 is a view for explaining another embodiment of the imaging element according to the present invention. FIG.
FIG. 5B is a view taken in the direction of the arrow B in FIG.
Is a light condensing element, 4b is a Fresnel lens, and other parts having the same functions as those in FIGS. 1 to 4 are denoted by the same reference numerals as those in FIGS.

According to a sixth aspect of the present invention, as shown in FIG. 5A, an image forming element is constituted by two sets of condensing elements 4, 4 and a roof prism whose two reflecting surfaces are at 90 degrees to each other. Then, the light beam incident on one of the light condensing elements 4 becomes parallel light, is deflected by the roof prism, exits from the other light condensing element 4 to form an image, and the incident light beam is deflected inside the roof prism. As a result, stray light is likely to be generated at both end portions of the valley between the arrayed optical axes, and as shown in FIG. 5B, the transmission member 3b having a refractive index close to the roof prism array so as not to cause regular reflection. Since the coating is applied to both ends of the valley between the optical axes of the roof prism array, the area for applying the transmitting member 3b is smaller than that of the invention of claim 5, and the light amount loss can be suppressed, and More effective application with less material applied It is obtained to be able to perform the photoablation.

[0030]

【The invention's effect】

(1) Effect of the first aspect of the present invention: regular reflection preventing means is provided on part and all of the ridges between the optical axes of the roof mirror array, so that stray light can be cut off, and the lens array and the roof can be cut off. The degree of freedom of the position of the mirror array increases. Furthermore, a high-quality image can be obtained without reducing the light amount.

(2) Advantageous effect of the second aspect: As the regular reflection preventing means, a part or all of the ridge between the optical axes of the roof mirror array is made flat, polyhedral, or curved, so that an optical path for stray light is desired. And the effect of stray light can be reduced as compared with the first aspect of the present invention.

(3) Advantages of the third aspect of the invention: As a means for preventing regular reflection, part and all of the ridges between the optical axes of the roof mirror array are roughened, so that the present invention is different from the second aspect of the invention. Thus, the regular reflection preventing means can be easily provided.

(4) Effect of the invention of claim 4: As the regular reflection preventing means, a part and all of the ridge portion between the optical axes of the roof mirror array are light absorbing members.
As compared with the invention of the first aspect, a high-quality image less affected by stray light can be obtained.

(5) Effect of the invention of claim 5: As a means for preventing regular reflection, the refractive index of the roof prism array is set at the valley between the optical axes of the roof prism array so that total reflection does not occur at the roof prism. By applying a transmissive member having a similar refractive index, it is possible to produce a product more easily and to capture a high-quality image.

(6) According to the sixth aspect of the present invention, in an image forming element composed of two sets of light-collecting elements and a roof prism whose two reflecting surfaces are at 90 degrees to each other, the roof prism array arrangement optical axis Since a transmissive member having a refractive index close to the refractive index of the roof prism array is applied so that total reflection does not occur at both ends of the valley, the loss of light amount can be suppressed, and the product can be more easily commercialized. High quality images can be captured.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram for explaining an embodiment of an imaging element according to the present invention.

FIG. 2 is a main part configuration diagram for explaining another embodiment of the imaging element according to the present invention.

FIG. 3 is a main part configuration diagram for explaining another embodiment of the imaging element according to the present invention.

FIG. 4 is a main part configuration diagram for explaining another embodiment of the imaging element according to the present invention.

FIG. 5 is a diagram for explaining another embodiment of the imaging element according to the present invention.

FIG. 6 is a main part configuration diagram for explaining an optical system for forming an equal-magnification real image according to a conventional technique.

FIG. 7 is a main part configuration diagram for explaining an example of an imaging element according to a conventional technique.

[Explanation of symbols]

1, 21: lens array, 2, 22: roof mirror array, 2a, 22a: roof mirror array array, ridge between optical axes, 2b: rough surface, 2c: light absorbing member, 3: roof prism array, 3a ... Valleys between the optical axes of the roof prism array, 3b: transmissive member, 4, 4a: light-collecting element, 4b ...
Fresnel lens, 11 condensing lens, 12 roof mirror, 13 optical path separating mirror, 14 original surface, 15 imaging surface, A image reading position, L, L 'light beam.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ikuo Maeda 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Narika Misawa 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Hiroyuki Inoue 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd.

Claims (6)

[Claims] 1. A light-collecting element array in which a plurality of optically-equivalent light-collecting elements are arranged in a line;
And a roof mirror array in which a plurality of optically equivalent roof mirrors are arranged in a row,
In the imaging element arranged so that the optical axis of each of the light condensing elements and the ridge line of each of the roof mirrors intersect, at least a part of the ridge portion between the roof mirror array array optical axes,
An imaging element comprising specular reflection preventing means for reducing a light flux that enters from a certain light-collecting element and is reflected by a roof mirror corresponding to the light-collecting element and exits from an adjacent imaging system. 2. The imaging element according to claim 1, wherein the specular reflection preventing means has a shape in which a ridge between the optical axes of the roof mirror array is flat, polyhedral, or curved. 3. The imaging device according to claim 1, wherein the specular reflection preventing means is a roughened surface having irregularities on the surface. 4. The imaging device according to claim 1, wherein said regular reflection preventing means is a light absorbing member. 5. A light-collecting element array in which a plurality of optically equivalent light-collecting elements are arranged in a line,
And an angle of 90 degrees between the two reflecting surfaces, and a roof prism array in which a plurality of optically equivalent roof prisms are arranged in a line. An imaging element arranged such that an axis intersects with a ridge line of each roof prism, wherein at least a part of a valley between the optical axes of the roof prism array is incident from a certain light condensing element and the light is condensed. A regular reflection preventing means comprising a transmitting member having a refractive index substantially equal to the refractive index of the roof prism array for reducing a light beam reflected by the roof prism corresponding to the element and emitted from an adjacent imaging system; An imaging element characterized by the above-mentioned. 6. A roof prism array in which an angle between two reflecting surfaces is 90 degrees and a plurality of optically equivalent roof prisms are arranged in a line in a direction orthogonal to a ridge line of each roof prism. An imaging element corresponding to each of the roof prisms, and a plurality of optically equivalent light collecting elements are integrally disposed on a light flux incident side and a light flux output side of each roof prism, In the imaging element arranged so that the ridge line of the roof prism and the optical axis of each of the light condensing elements corresponding to each roof prism intersect, at least a part of the valley between the roof prism array array optical axes, A light beam incident from a certain light-collecting element and reflected by a roof prism corresponding to the light-collecting element has a refractive index substantially equal to the refractive index of the roof prism array for reducing a light beam emitted from an adjacent imaging system. An imaging element comprising a regular reflection preventing means made of a transmission member having a bending ratio.