JPH1164786A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device constituted so that the loss of light quantity by an aperture array member is suppressed. SOLUTION: The aperture array constituting members 2a and 2b are identically shaped. Then, identically shaped projection parts 21a and 21b and identically shaped recessed parts 22a and 22b are alternately arranged on both sides of apertures 10 and 11 at a plane surface on which the apertures 10 and 11 are formed. Then, the constituting members 2a and 2b are arranged so that the axial directions of the aperture 10 of the member 2a and the aperture 11 of the member 2b are orthogonally crossed. Thus, the recessed and the projecting parts 22a and 21a of the member 2a and the projecting and the recessed parts 21b and 22b of the member 2b are engaged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, 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 a structure of an aperture array of an imaging apparatus suitable for use in a system or an optical system used in an optical print head or a self-scanning optical print head.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram of a main part for explaining an optical system for forming a real-size real image according to the prior art.
Is a lens array, 102 is a roof mirror array, 103
Is a roof mirror lens array, 104 is a lens, 105
Is a ridge line, 106 is a roof mirror, 107 is an object plane, 10
8 image plane, 109 optical path separating mirror, P ₁ is the reading position,
P ₂ is the imaging position, phi is the optical axis.

The optical system for forming a real-size real image shown in FIG.
Set the reading position P ₁ of the object plane 107 to a finite slit height position not on the optical axis φ of the lens 104, the lens 104
, The light is turned back by the roof mirror 106 in the same direction, and the same lens 104 is again turned on.
Was allowed to pass, it is obtained so as to form an image in an optically conjugate position P _2.

As a prior art, for example, Japanese Patent Publication No. 61-2
No. 929 discloses an in-prism lens array in which a lens array and a roof mirror array are integrally formed. As in the example shown in FIG. The reading position is set at the center position, and after the reflected light passes through the lens surface, it is reflected twice by the roof prism, passes through the lens surface again, and forms an image at a common 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 Publication No. 26 (1993), are known, and a "lens array" in which a series of lenses equivalent to an optical system are arranged in a line, and a lens in this lens array A “roof mirror array” in which a series of roof mirrors having ridge lines orthogonal to the arrangement direction and the lens optical axis direction are arrayed in a one-to-one correspondence with individual lenses in the lens array; It is arranged between the roof mirror array and
An "aperture member" for separating an imaging system formed by a lens and a roof mirror from each other is integrated, and is used for exposing a photosensitive member with a document image, reading a document, or reading an image.

In any case, in this type of imaging element, an arbitrary lens in the lens array forms one "imaging system" with the corresponding roof mirror,
Each aperture of the aperture member must be located corresponding to each of these imaging systems and optically separate the imaging systems from each other.
In other words, with this type of imaging element, it is impossible to lay out the reading position and the imaging position at the same position in order to pass the same lens back and forth, and the luminous flux on the optical axis is
In order to separate the light beam on the object side and the light beam on the imaging plane side, a finite slit height must be used. That is, to set the position P ₁ read on the finite image height position in the direction of the ridge 105 of the roof mirror 106, the imaging position P _2, it is necessary for forming the minus image height position of. However, since the amount of separation is limited, the optical path is actually turned back by the optical path separating mirror 109 or the like as shown in FIG. The optical path separating mirror 109 shown in FIG. 7 is a strip-shaped flat mirror that is long in the front and back directions on the paper surface.
Are arranged at an angle of 45 ° with respect to a plane sharing the optical axis φ.

[0007]

However, as described above, in the roof mirror lens according to the prior art, since the image forming light beam passes through the same lens twice, the direction of the ridge line (perpendicular to the arrangement direction of the roof mirror lens). Direction), the image plane and the image plane must be set at a finite image height position, and the layout is restricted. Also, in reality, as described above,
It is necessary to dispose the optical path separating mirror 109. Here, in order for the roof mirror and the optical path separating mirror to have a reflection surface configuration, it is necessary to form a reflection film by a vacuum deposition process using a high reflectance material such as Al, which is inferior in productivity. In addition, the reflectance is limited to about 90% at most because a protective film and the like are also formed due to reliability and the like.
More specifically, in the case of the configuration as shown in FIG. 7, since the roof mirror 106 has two reflecting surfaces and the optical path separating mirror 109 has two reflecting surfaces, only a reflectance of about 66% can be secured as a whole. In addition, if there are a plurality of vapor-deposited reflection surfaces, the reflection loss will be generated as much as possible, so that there is a problem that the imaging element has a large light amount loss.

Further, as described above, the roof mirror lens array according to the prior art employs two lenses having the same imaging light flux.
Therefore, the image plane and the image plane must be set at a finite image height position in a direction orthogonal to the arrangement direction of the roof mirror lenses. Further, similarly to the problem of the roof mirror lens, there is a problem that at least three or more reflecting surfaces of the roof mirror 2 and the optical path separating mirror 1 need to be formed, so that the loss of effective light increases. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an imaging apparatus in which the loss of light amount due to an aperture array member is suppressed.

[0010]

According to a first aspect of the present invention, there is provided a lens having an incident side lens and an image forming side lens having optical axes set in different directions and exhibiting optically equivalent light collecting functions, and a ridge line. A roof prism having a plane at 90 ° to each other and including the optical axes of both of these lenses, wherein the ridge is disposed at a position where the optical axes intersect with each other; A roof prism lens array in which the lens and the roof prism are arranged in a line in a direction orthogonal to the ridge line of the prism; and an opening arranged on the front surface of the roof prism lens array at the same pitch as the arrangement pitch of the roof prism lenses. In an imaging apparatus comprising an aperture array for adjusting the amount of light, the aperture array is constituted by two plate-shaped aperture array members having the same shape, and each aperture array is formed. The planes provided with the openings of the constituent members are arranged so that the planes are orthogonal to each other, and the uneven portions provided on the longitudinal side of one of the opening array constituent members are arranged in the longitudinal direction of the other opening array constituent member. It is provided so as to be engaged with the concave and convex portions provided in the portion, so as to eliminate a pair of hole position errors in the opening arrangement direction.

According to a second aspect of the present invention, in the first aspect of the present invention, the concave and convex portions provided on the longitudinal side of the aperture array constituting member are provided only on one longitudinal side of the aperture array constituting member. In this case, the degree of freedom in design and the precision of the pitch of the aperture arrangement are improved.

According to a third aspect of the present invention, there is provided a lens having an incident side lens and an image forming side lens whose optical axes are set in different directions and exhibiting optically equivalent light condensing functions, and a lens which forms a ridge line by 90 ° with respect to each other. And a roof prism on which a ridge is disposed on a plane including both optical axes of these lenses and at a position where the optical axes intersect, and which is orthogonal to the ridge of the roof prism. A roof prism lens array in which the lenses and the roof prism are arranged in a line in a direction in which the roof prism lens array is arranged, and an opening arranged at the same pitch as the arrangement pitch of the roof prism lenses on the front surface of the roof prism lens array to adjust the light amount In an imaging device comprising an array, the aperture array is formed by folding a flat plate provided with two rows of openings in a concave portion having a V-shaped cross section provided between the two rows of openings. By gel, wherein characterized in that each opening array is formed as a surface that is provided is perpendicular, in which aimed at cost reduction by ease of creation.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram of a main part of an embodiment of an image forming apparatus to which the present invention is applied.
1 is a roof prism lens array, 2 is an aperture array, 3
Is a roof prism lens, 4 is a light incident side lens, 5 is an imaging side lens, 6 is a ridgeline, 7 and 8 are planes, 9 is a roof prism section, 10 and 11 are apertures, 12 is a document surface, L ₁ and L. ₂ is stray light, and φ ₁ and φ ₂ are optical axes.

The imaging element in the embodiment shown in FIG.
A roof prism lens array 1 and an aperture array 2 serving as a diaphragm member are combined. Here, the roof prism lens array 1 is configured by arranging roof prism lenses 3 individually forming an imaging system in a single row. The roof prism lens 3, which is the minimum unit of the image forming system, includes an optically equivalent entrance side lens 4
And a lens 5 on the imaging side, and a roof prism portion 9 having planes 7 and 8 forming 90 ° with each other and forming a ridge line 6 and arranged at a position where the optical axes of both lenses 4 and 5 intersect. Are formed integrally, and the optical axes φ ₁ and φ ₂ of the lenses 4 and 5 are
Are orthogonal to each other, and on a plane including these optical axes φ ₁ and φ ₂ , a ridge line 6 located at a position where the optical axes φ ₁ and φ ₂ intersect is
These optical axes are inclined by 45 ° with respect to φ ₁ and φ ₂ .
Therefore, the array direction as the roof prism lens array 1 is set to a direction orthogonal to the ridgeline 6. The aperture array 2 has openings 1 at the same pitch as the arrangement pitch of the lenses 4 and 5 in the roof prism lens array 1.
0, 11 are formed.

In such a configuration, the optical axis of each incident side lens 4 is on a plane that includes the ridge line 6 of the roof prism section 9 and is orthogonal to the array direction. The light is converted into parallel light by the side lens 4 and enters the corresponding roof prism unit 9. After being reflected twice by the planes 7 and 8 in the roof prism section 9, the ridge 6
Is twice as large as the tilt angle (45 ° here), that is, 9
It is bent by 0 ° and exits from the imaging side lens 5. The image is focused and formed on the image forming surface by the image forming side lens 5. Since the image forming side lens 5 is optically equivalent having the same light collecting function as the incident side lens 4, it has an optimum image forming surface at a position opposite to the reading position on the document surface. I have. Further, in such an image forming process, since the light is reflected twice by each roof prism section 9, the image formed is
It becomes an erect 1: 1 image. In this case, the single effective reading width by the individual lenses 4 and 5 is overlapped with each other while being shifted by the arrangement pitch, thereby covering the necessary effective width. As a result, the focal lengths of the individual lenses 4 and 5 can be shortened, which contributes to the downsizing of the imaging element.

In this embodiment mode, FIG.
As shown in the figure, when there are stray lights L ₁ and L ₂ , the light reflected by the roof prism unit 9 has a bad influence on the image forming light. However, since the aperture array 2 is provided, these stray lights L
_1, L ₂ such adverse effect is reliably prevented against the wall surface of the opening 10 (11). In FIG. 1 (D), for simplicity of description, an optically equivalent two-dimensional state is shown instead of an actual three-dimensional state.

FIG. 2 is a perspective view for explaining an embodiment of the aperture array of the image forming apparatus according to the present invention.
2b is an aperture array constituent member, 21a and 21b are convex portions, 2
Reference numerals 2a and 22b denote recesses, and other portions having the same functions as those of the embodiment shown in FIG. 1 are denoted by the same reference numerals as those of the embodiment shown in FIG. FIG. 3 is a diagram for explaining the amount of light when an error occurs in the opening position of the opening array.

The embodiment shown in FIG. 2 is similar to the embodiment shown in FIGS.
As shown in (B), in the plane where the openings 10 and 11 are provided, the protrusions 21a and 22b and the recesses 22a and 22b having the same shape are alternately arranged on both sides of the openings 10 and 11. The aperture array 2 is composed of the aperture array components 2a and 2b. As shown in FIG. 2C, the axial direction of the opening 10 of the aperture array component 2a and the axis of the aperture 11 of the aperture array component 2b. The direction is orthogonal to the direction, and the concave and convex portions 22a,
21a and the concave and convex portions 21b and 22 of the aperture array constituting member 2b
b.

As described above, the aperture array components 2a,
By using members of the same shape as 2b, it is possible to reduce the positional error in the arrangement direction of the pair of openings 10, 11 in the arrangement direction. When a positional error in the arrangement direction of the openings 10 and 11 occurs, the amount of light decreases as shown in FIG. 3B, but according to the invention of claim 1, the holes in the arrangement direction of the openings 10 and 11 are formed. Since the position error is small, a decrease in the amount of light can be suppressed as shown in FIG. In addition, it is preferable that the opening array constituent members 2a and 2b are formed by, for example, resin molding.

FIG. 4 is a view for explaining another embodiment of the aperture array of the image forming apparatus according to the present invention. FIGS. 4 (A) and 4 (B) are perspective views and FIG. 4 (C). Is a main part configuration diagram, in which 2c and 2d are aperture array components, 1c, 1d and 2
1c and 21d are convex parts, 22c, 22d, 23c and 23d
Is a concave portion, and other portions having the same functions as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals as those in the embodiment shown in FIG.

The embodiment shown in FIG. 4 is similar to the embodiment shown in FIGS.
As shown in (B), in the plane where the openings 10 and 11 are provided, the same shape in which the protrusions 21c and 21d and the recesses 22c and 22d of the same shape are alternately arranged on one side of the openings 10 and 11. The aperture array 2 is composed of the aperture array components 2c and 2d, and as shown in FIG. 4C, the axial direction of the opening 10 of the aperture array component 2c and the aperture 11 of the aperture array component 2d. The projections and depressions 22 of the aperture array component 2c are arranged so that the axial direction is orthogonal to the axis direction.
c, 21c and the projections and depressions 21d of the aperture array constituent member 2d.
22d.

Further, for example, concave portions 23c and 23d are provided at the ends of the opening array constituting members 2c and 2d on the opposite side to the concave and convex portions for engaging the opening array constituting members 2c and 2d. Convex portions 1c, 1d on prism array 1
May be provided, and these may be engaged and fixed.

FIGS. 5 and 6 are views for explaining another embodiment of the aperture array of the imaging apparatus according to the present invention.
6A and 6A are perspective views, and FIGS.
(C), FIG. 6 (B), and FIG. 6 (C) are cross-sectional views of a main part, in which 2e and 2f are aperture array constituent members, and FIG.
4 to FIG. 4 are denoted by the same reference numerals as those in the embodiment shown in FIG. 1 to FIG.

The embodiment shown in FIG. 5 and FIG.
(A), as shown in FIG.
11 are integrally formed in a flat plate structure, and are bent at the center of the opening array constituent members 2e and 2f as shown in FIGS. 5B and 6B.
As shown in FIGS. 5C and 6C, the opening array member 2 is formed by forming an L-shape such that the surface having the opening 10 and the surface having the opening 11 are orthogonal to each other. It is like that.

[0025]

According to the first aspect of the present invention, a lens having an incident side lens and an image forming side lens whose optical axes are set in different directions and exhibits optically equivalent light-collecting functions, and a lens forming an edge line are provided. A roof prism having a plane that forms 90 ° and including both optical axes of these lenses, and the ridge line being disposed at a position where the optical axis intersects, and the ridge line of the roof prism A roof prism lens array in which the lenses and the roof prism are arranged in a row in a direction perpendicular to the direction of the roof prism, and an opening arranged at the same pitch as the arrangement pitch of the roof prism lenses on the front surface of the roof prism lens array to adjust the amount of light In an imaging apparatus comprising an aperture array having a flat shape, the aperture array has a flat plate shape having the same shape.
A plurality of aperture array components, the apertures of the aperture array components are arranged so that the planes on which the apertures are provided are orthogonal to each other, and provided on the longitudinal side of one of the aperture array components. Since the concave and convex portions are arranged to engage with the concave and convex portions provided on the longitudinal side of the other opening array constituent member, by using the same member,
It is possible to eliminate a hole position error in the paired opening arrangement direction.

According to a second aspect of the present invention, in the first aspect of the present invention, the concave and convex portions provided on the longitudinal side of the aperture array constituting member are provided only on one longitudinal side of the aperture array constituting member. Therefore, the degree of freedom in the layout design in combination with the roof prism lens array is improved, and the arrangement pitch accuracy can be adjusted to high accuracy, so that higher quality reading can be realized.

According to a third aspect of the present invention, there is provided a lens having an incident side lens and an imaging side lens whose optical axes are set in different directions and exhibiting an optically equivalent light-collecting function, and a lens which forms a ridge line by 90 °. And a roof prism on which a ridge is disposed on a plane including both optical axes of these lenses and at a position where the optical axes intersect, and which is orthogonal to the ridge of the roof prism. A roof prism lens array in which the lenses and the roof prism are arranged in a line in a direction in which the roof prism lens array is arranged, and an opening arranged at the same pitch as the arrangement pitch of the roof prism lenses on the front surface of the roof prism lens array to adjust the light amount In an imaging device comprising an array, the aperture array is formed by folding a flat plate provided with two rows of openings in a concave portion having a V-shaped cross section provided between the two rows of openings. By gel, wherein since each aperture array is formed as a surface that is provided is perpendicular, improved convenience for Creating mold structure becomes simplified, and further,
Since the L-shaped aperture array can be provided by one component, the production time, that is, the molding time can be reduced, so that a very inexpensive L-shaped aperture array can be provided.

[Brief description of the drawings]

FIG. 1 is a main part configuration diagram for explaining an embodiment of an imaging apparatus to which the present invention is applied.

FIG. 2 is a perspective view for explaining an embodiment of an aperture array of the imaging apparatus according to the present invention.

FIG. 3 is a diagram for explaining a light amount when an error occurs in an opening position of an opening array.

FIG. 4 is a view for explaining another embodiment of the aperture array of the imaging apparatus according to the present invention.

FIG. 5 is a view for explaining another embodiment of the aperture array of the imaging apparatus according to the present invention.

FIG. 6 is a view for explaining another embodiment of the aperture array of the imaging apparatus according to the present invention.

FIG. 7 is a main part configuration diagram for explaining an optical system for forming an equal-magnification real image according to a conventional technique.

[Explanation of symbols]

1. Roof prism lens array, 1c, 1d, 21
a, 21b, 21c, 21d ... convex part, 2 ... aperture array,
2a, 2b, 2c, 2d, 2e, 2f: Aperture array member, 3: Roof prism lens, 4: Light entrance side lens,
5: imaging side lens, 6: ridge line, 7, 8: flat surface, 9: roof prism portion, 10, 11: opening, 12: original surface, 22
a, 22b, 22c, 22d, 23c, 23d...
101: lens array, 102: roof mirror array,
103: roof mirror lens array, 104: lens,
105: ridge line, 106: roof mirror, 107: object plane, 108: image plane, 109: optical path separating mirror, L ₁ , L ₂
... Stray light, P ₁ ... Reading position, P ₂ ... Image forming position, φ, φ ₁ , φ ₂
…optical axis.

Claims (3)

[Claims] 1. A lens having an incident-side lens and an imaging-side lens whose optical axes are set in different directions and exhibiting an optically equivalent light-collecting function, and a plane which forms a ridge and forms 90 ° with each other. And a roof prism on which a ridge is disposed on a plane including both optical axes of these lenses and at a position where the optical axes intersect, and wherein the lens is arranged in a direction orthogonal to the ridge of the roof prism. And a roof prism lens array in which the roof prisms are arranged in a line, and an aperture array for adjusting the amount of light by arranging openings on the front surface of the roof prism lens array at the same pitch as the arrangement pitch of the roof prism lenses. In the imaging apparatus, the aperture array is composed of two flat plate-shaped aperture array members having the same shape, and the plane of each of the aperture array members is provided with an opening. Are arranged so as to be orthogonal to each other, and the concave and convex portions provided on the longitudinal side of one of the opening array constituent members engage with the convex and concave portions provided on the longitudinal side of the other opening array constituent member. An imaging apparatus characterized in that the imaging apparatus is arranged so as to perform 2. The imaging apparatus according to claim 1, wherein the concave and convex portions provided on the longitudinal side of the aperture array member are provided only on one longitudinal side of the aperture array member. An imaging device characterized in that: 3. A lens having an incident side lens and an image forming side lens whose optical axes are set in different directions and exhibits an optically equivalent light-collecting function, and a plane which forms a ridge and forms a 90 ° angle with each other. And a roof prism on which a ridge is disposed on a plane including both optical axes of these lenses and at a position where the optical axes intersect, and wherein the lens is arranged in a direction orthogonal to the ridge of the roof prism. And a roof prism lens array in which the roof prisms are arranged in a line, and an aperture array for adjusting the amount of light by arranging openings on the front surface of the roof prism lens array at the same pitch as the arrangement pitch of the roof prism lenses. In the imaging device, the aperture array is formed by bending a flat plate provided with two rows of apertures at a concave portion having a V-shaped cross-section provided between the two rows of apertures. Imaging apparatus characterized by serial face each opening array is provided is formed so as to be orthogonal.