JP3441549B2 - Roof mirror lens array - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a "roof mirror lens array".

[0002]

2. Description of the Related Art A roof mirror lens array is an "optical system for forming a real image of equal magnification", which is a "lens array" in which a series of optically equivalent lenses is arranged in one row, and this lens. A "roof mirror array" in which a series of roof mirrors having ridge lines orthogonal to the lens array direction and the lens optical axis direction in the array are arrayed in a 1: 1 correspondence with the individual lenses in the lens array; A “diaphragm member” which has an array array of openings corresponding to the lens array in the lens array, is arranged between the lens array and the roof mirror array, and separates the image forming systems of the lens and the roof mirror from each other. These are integrated and are used for exposure of a photoreceptor by a document image, reading of a document, or writing of an image, and various types are conventionally known (for example, Akira 57-37326 JP, etc.).

FIG. 8 shows a typical structure of a "roof mirror lens array". In (a), reference numeral 1 is a lens array, reference numeral 2 is a diaphragm member, and reference numeral 3 is a roof mirror array.

The lens array 1 is an array of a series of optically equivalent lenses having a positive refractive power, which are arrayed in a row at a predetermined pitch in a direction orthogonal to the drawing and are integrated.

The roof mirror array 3 is a "roof mirror" formed by a pair of plane mirrors tilted at an angle of 90 degrees with respect to the vertical direction of the drawing, and is orthogonal to the drawing at the same pitch as the arrangement pitch of the lenses in the lens array 1. The roof mirrors are arranged so as to correspond 1: 1 to the individual lenses in the lens array.

Therefore, the ridge line formed by the seam of the mirror surfaces of the individual roof mirrors constituting the roof mirror array 3 is orthogonal to the "lens array direction and lens optical axis direction in the lens array 1."

The diaphragm member 2 is, as shown in FIG.
The openings 20 are formed in series at the same pitch as the lens array pitch in the lens array 1, and are arranged between the lens array 1 and the roof mirror array 3.

Any lens in the lens array 1 is
A corresponding roof mirror and "imaging system" are formed, and each aperture 20 of the diaphragm member 2 is located corresponding to each of these imaging systems, and separates the imaging systems from each other (optically). .

The lens array 1, the roof mirror array 3 and the diaphragm member 2 are integrated by a casing 10 while maintaining their mutual positional relationship.

A mirror indicated by reference numeral 13 in FIG. 8 (a) is a rectangular flat mirror that is long in a direction orthogonal to the drawing, and is 4 with respect to "a surface sharing the optical axis of each lens" of the lens array 1.
It is deployed with an inclination of 5 degrees.

The individual lenses in the lens array 1 are
The object side focal plane is made to coincide with the object plane 30. Therefore, the light emitted from the point P on the object plane 30 becomes a parallel light flux when it is incident on one of the lenses in the lens array 1, passes through the aperture of the aperture array 2, and passes through the aperture of the roof mirror array 3.
The light enters the roof mirror corresponding to the lens and is reflected as a parallel light beam.

The reflected light flux passes through the aperture and the lens in reverse, becomes a condensed light flux by the lens, is reflected by the mirror 13, and forms an image at a point Q on the image plane 40.

Since the respective lenses of the lens array 1 and the respective roof mirrors corresponding to the respective lenses in the roof mirror array 3 constitute an optically equivalent "imaging system", a point Q on the image plane 40 is formed. An equal-magnification image of a linear region that passes through the point P on the object plane 30 and is orthogonal to the drawing is formed in the linear region that passes through and is orthogonal to the drawing.

Therefore, for example, the original is placed so as to match the object plane 30, and while the linear area passing through the point P is illuminated by the illumination light source 50, the original is conveyed at a constant speed upward in the drawing, and the image plane 4 is displayed.
By driving the "equal-size reading element" in which the light receiving portion is aligned with the linear area passing through the point Q of 0, the original image can be read.

Alternatively, while arranging the LED array so as to match the linear region passing through the point P and moving the surface of the photosensitive medium, which coincides with the image plane 40, in the left and right direction of the drawing,
Image writing can be performed by applying an image signal to the LED array.

Alternatively, instead of the mirror 13 in FIG. 8A, two strip-shaped mirrors disclosed in FIG. 6 of the above-mentioned Japanese Patent Laid-Open No. 57-37326 are arranged in parallel with each other in the longitudinal direction. By using a combination of "curve shape", the object plane and the image plane can be made parallel to each other, so that the original image can be formed on the photosensitive medium.

As described above, in the conventional roof mirror lens array, the image forming light flux passes through the same lens twice, and
Since the configuration is an “oblique light flux” that is tilted with respect to the optical axis of each lens in the lens array, FIG.
There is a considerable amount of stray light as shown by the broken line (in this example, it is reflected by the lens surface and enters the image forming position Q) or is reflected by the side wall of the opening of the light shielding member and reaches the image forming position Q. However, it has been a cause of lowering the resolution of image formation and the contrast.

[0018]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel roof mirror lens array capable of effectively reducing the influence of stray light (claim 1). ~ 6).

[0019]

The "roof mirror lens array" according to claim 1 has a lens array, a roof mirror array, and a diaphragm member.

The "lens array" is an array of optically equivalent lenses arranged in a line.

The "roof mirror array" is an array arrangement in which a series of roof mirrors having ridge lines orthogonal to the lens array direction and the lens optical axis direction in the lens array are arranged in a 1: 1 correspondence with the individual lenses in the lens array. I will do it.

The "diaphragm member" is a member that optically separates the individual imaging systems formed by the lens and the roof mirror from each other, but "a plurality of apertures separated in the diaphragm member width direction for each lens". Have.

The lens array, roof mirror array and diaphragm member are integrated.

The "roof mirror lens array" according to claims 2 to 6 is constructed by integrating two or more diaphragm members together with the lens array and the roof mirror lens array.

At least one of the two or more diaphragm members is "separated in the width direction of the diaphragm member" for each lens.
It has a plurality of openings.

The "diaphragm member width direction" is a direction parallel to the "ridge line" of the roof mirror when the diaphragm member is integrated with the lens array and the roof mirror array.

According to the second aspect of the present invention, since the number of diaphragm members is two or more, it is possible to use three or more diaphragm members. However, when two diaphragm members are used, they are "both the lens array and the roof. It may be arranged such that it is “disposed between the mirror array” (claim 3) or the two diaphragm members are “arranged to hold the lens array” (claim 4).

When "holding the lens array with two diaphragm members" as in the fourth aspect of the present invention, an "optical path separation mirror" for separating the optical path from the object side and the optical path to the image side. Can be integrated with "a diaphragm member on the opposite side of the lens array from the roof mirror array (a diaphragm member that is not sandwiched by the lens array and the roof mirror array)" (claim 5).

In the roof mirror lens array according to any one of claims 3 to 5, at least one of the two diaphragm members has "a plurality of apertures for each lens".
However, the other diaphragm member may have "one aperture corresponding to each lens" (claim 6).

[0030]

As described above, in the roof mirror lens array of the present invention, the diaphragm member has a plurality of openings for each lens. The plurality of openings are separated in the width direction of the diaphragm member.

The "imaging light flux" in each "imaging system (consisting of the lens and the roof mirror)" in the roof mirror lens array is an oblique light flux with respect to the lens optical axis in the lens array (FIG. 8). (See (a)). This oblique light flux is inclined with respect to the “plane that shares the optical axis of each lens” of the lens array.

The image-forming light flux in each of the above-mentioned image-forming systems reaches the roof mirror through one of the openings separated in the width direction of the diaphragm member, and reaches the image plane through the opening on the opposite side in the width direction of the diaphragm member. Go to

As described above, in each image forming system, the light beam incident from the object side and the light beam toward the image plane are separated in the width direction of the light shielding member by the plurality of openings in the light shielding member.

[0034]

EXAMPLES Specific examples will be described below. In order to avoid complication, the lens array and the roof mirror array have the same reference numeral 1 as in FIG.
And 3, the illustration of the “casing” is omitted in each embodiment.

The optical path separating mirror (mirror 13 in FIG. 8A) is not shown if it is not particularly necessary.

FIG. 1 (a) schematically shows only an essential part of one embodiment of the invention according to claim 1. In this figure, the mirror for separating the optical paths is omitted, so that the object plane and the image plane are drawn as a common plane 300.

The lens array 1 is formed by arranging a series of lenses arranged so that the focal plane on the object side matches the surface 300 as the object surface, in one row in the direction orthogonal to the drawing,
It is a molded product made of plastic.

The roof mirror array 3 is the lens array 1
A series of roof mirrors each having a ridge line (vertical direction in the drawing) orthogonal to the lens array direction and the lens optical axis direction in 1) are arrayed in a 1: 1 correspondence with each lens in the lens array 1. It is a molded product made of plastic.

Reference numeral 2A indicates a diaphragm member. Aperture member 2A
Is a molded product made of plastic or the like, and is disposed between the lens array 1 and the roof mirror array 3, and separates the imaging system formed by the lens and the roof mirror from each other. The lens array 1, the roof mirror array 3, and the diaphragm member 2A are wholly integrated by a casing (not shown).

As shown in FIG. 1B, the circular member 2A has "circular openings" arranged in two rows in the longitudinal direction. Two apertures arranged in the width direction of the diaphragm member form a “pair”, and each pair of apertures corresponds to each lens. In other words, the diaphragm member 2A has “two openings separated in the diaphragm member width direction” for each lens in the lens array 1.

Light from a position P (for example, a document reading position) on the surface 300 serving as the object surface passes through the lens as shown by the solid line and passes through the aperture on one side (upper side in the figure) of the diaphragm member 2A in the width direction. When it reaches the roof mirror and is reflected, it passes through the opening on the other side (lower side in the drawing) of the diaphragm member 2A in the width direction, passes through the lens, and is moved to the position Q on the surface 300 as an image plane.
An image is formed at (for example, a document image capturing position).

If the aperture of the diaphragm member corresponding to the lens is a "single aperture", for example, the light SL from the original portion p other than the original reading position P in FIG.
(Indicated by a broken line) may be reflected at the position q of the inner wall of the aperture of the diaphragm member and reach the document image capturing position Q as stray light. In this embodiment, the aperture corresponding to each lens is a diaphragm member. Since they are separated in the width direction, as shown in the figure, they are blocked by the separation part of the aperture and do not reach the image plane as stray light.

The size and arrangement of the apertures can be optimized by a simulation based on ray tracing so that the total amount of light on the image plane, in particular, the amount of light that overlaps with each other in the image forming systems becomes uniform.

Two other examples of the diaphragm member are shown in FIG.

In the diaphragm member 2B shown in FIG. 2 (a), a pair of openings separated in the width direction of the diaphragm member each have a shape of "half a slot". In this case, since the shape of the "pair of apertures" corresponding to each lens is close to a circle, the light amount distribution of each lens is close to a Gaussian distribution, and it is easy to make the combined light amount uniform on the image plane.

In the diaphragm member 2C shown in FIG. 2B, "two openings separated in the width direction of the diaphragm member" have a rectangular shape corresponding to each lens. This way,
The dead space between adjacent lenses is effectively reduced, the light utilization efficiency of each lens is improved, and a bright image can be formed.

Example 2 of diaphragm member shown in FIGS. 2 (a) and 2 (b)
The shape, size, and arrangement of the openings in B and 2C can also be optimized by simulation by ray tracing.

3 to 6 show an embodiment of the invention described in claims 2, 3, 4, and 6.

FIGS. 3 and 4 show an embodiment of the invention described in claims 2, 3 and 6.

In FIG. 3, reference numerals 2a and 2D indicate two diaphragm members. The diaphragm members 2a and 2D are both arranged between the lens array 1 and the roof mirror array 3 (claim 3).

The diaphragm member 2D is a diaphragm member in which a plurality of apertures are formed for each lens. Specifically, FIG.
A diaphragm member 2A shown in (a) and diaphragm members 2B and 2C shown in FIGS. 2 (a) and 2 (b) can be used.

The diaphragm member 2a has a "single aperture for each lens" (claim 6). Specifically, FIG.
A thing like the diaphragm member 2 shown in (b) can be used.

In FIG. 4, reference numerals 2b and 2E indicate two diaphragm members. The diaphragm members 2b and 2E are both arranged between the lens array 1 and the roof mirror array 3 (claim 3).

The diaphragm member 2E is a diaphragm member in which a plurality of apertures are formed for each lens. Specifically, FIG.
Aperture member 2A shown in (a) and aperture members like aperture members 2B and 2C shown in FIGS. 2 (a) and 2 (b) can be used.

The diaphragm member 2b has a single aperture for each lens (claim 6), and specifically, an aperture-shaped product such as the diaphragm member 2 shown in FIG. 8B can be used.

In the embodiment of FIG. 4, the diaphragm member 2b,
As shown in FIG. 3, the opening of 2E has a “tapered sectional shape” in the thickness direction of the diaphragm member.
Is different from the embodiment described above.

As shown in the embodiments of FIGS. 3 and 4, by combining two diaphragm members, the degree of freedom in design for removing stray light and optimizing the light amount distribution on the image plane is increased. Further, if the two diaphragm members shown in FIGS. 3 and 4 are focused only on the function, they may be integrally formed. However, in that case, molding with resin becomes extremely difficult.
If two independent drawing members are used, they can be formed and processed very easily.

FIGS. 5 and 6 show an embodiment of the invention according to claims 2, 4 and 6.

In FIG. 5, reference numerals 2d and 2F indicate two diaphragm members. The diaphragm members 2d and 2F are both arranged so as to hold the lens array 1 (claim 4).

The diaphragm member 2F is a diaphragm member in which a plurality of apertures are formed for each lens. Specifically, FIG.
A diaphragm member 2A shown in (a) and diaphragm members 2B and 2C shown in FIGS. 2 (a) and 2 (b) can be used.

The diaphragm member 2d has a single aperture for each lens (claim 6). Specifically, FIG. 8 (b).
It is possible to use a material such as the diaphragm member 2 shown in FIG.

In FIG. 6, reference numerals 2e and 2G indicate two diaphragm members. The diaphragm members 2e and 2G are both arranged so as to hold the lens array 1 (claim 4).

The diaphragm member 2G is a diaphragm member in which a plurality of apertures are formed for each lens. Specifically, FIG.
Aperture members 2A shown in (a) and aperture members such as the aperture members 2B and 2C shown in FIGS. 2 (a) and 2 (b) can be used.

The aperture member 2e has a single aperture for each lens (claim 6), and specifically, an aperture member such as the aperture member 2 shown in FIG. 8B can be used.

The embodiments shown in FIGS. 5 and 6 are similar to the embodiments of FIGS. 3 and 4 by using two diaphragm members.
The degree of freedom in design for removing stray light and optimizing the light amount distribution on the image plane is increased.

Further, since one of the two diaphragm members is on the opposite side of the lens array 1 from the roof mirror 3, "stray light due to reflection on the lens surface (see FIG. 8A)" is effective. It is blocked and the influence of flare on the image plane can be reduced.

Also in the embodiment of FIGS. 5 and 6, the diaphragm member 2
The openings in d, 2e, 2F, and 2G may be tapered in the thickness direction of the diaphragm member as in the case of the embodiment of FIG.

FIG. 7 shows an embodiment of the invention described in claims 5 and 6. 7 (a) and 7 (b), the same reference numerals as those in FIG. 8 (a) are attached to those which are considered to have no possibility of confusion.

In FIG. 7A, of the two diaphragm members 2f and 2H arranged so as to hold the lens array 1, the diaphragm member 2f has a single aperture for each lens. 6), specifically, an aperture-shaped object such as the diaphragm member 2 shown in FIG. 8B can be used.

The diaphragm member 2H is a diaphragm member in which a plurality of apertures are formed for each lens.
Aperture member 2A shown in (a) and aperture members like aperture members 2B and 2C shown in FIGS. 2 (a) and 2 (b) can be used.

In this embodiment, the optical path separating mirror 13 for separating the optical path from the object side and the optical path to the image side.
However, the lens array 1 is integrated with the diaphragm member 2H on the opposite side of the roof mirror array 3.

That is, in the diaphragm member 2H, the mirror 13 is integrated with the portion of the separating portion 2H1 which separates a plurality of openings for each lens in the diaphragm member width direction.

In the embodiment shown in FIG. 7B, two diaphragm members 2 arranged so as to hold the lens array 1 therebetween.
Of f and 2J, the diaphragm member 2f is the same as that in FIG. 7 (a).

The diaphragm member 2J is a diaphragm member in which a plurality of openings are formed for each lens, and the separating portion 2 which separates the plurality of openings for each lens in the diaphragm member width direction.
The portion J1 projects to the side opposite to the lens array 1, and the mirror 13 is integrated at the projecting end.

In the embodiment of FIG. 7 as well, similar to the embodiments of FIGS. 3 and 4, by using two diaphragm members, the degree of freedom in design for removing stray light and optimizing the light quantity distribution on the image plane. Since one of the two diaphragm members is on the opposite side of the lens array 1 from the roof mirror 3, "stray light due to reflection on the lens surface" is effectively blocked, and the influence of flare on the image plane is reduced. Can be reduced.

Also, since the object side and the image side are "spatially shielded" by the integration of the diaphragm member and the mirror 13, flare light scattered inside the roof mirror lens array is hard to reach the image side. , The resolution and contrast of image formation are improved more effectively.

In the case of the embodiment shown in FIG. 7B, since the separating portion 2J1 is projected toward the mirror 14 in order to hold the mirror 13, even if the distance between the mirror 13 and the lens array 1 is large, It is not necessary to increase the thickness of the diaphragm member 2J, and the degree of freedom in layout of the mirror 13 is increased.

[0078]

As described above, according to the present invention, a novel roof mirror lens array can be provided. Since the roof mirror lens array of the present invention is configured as described above, it is possible to effectively prevent the light reflected and scattered inside the roof mirror lens array from acting as stray light on the image forming portion. There are (claims 1 to 6).

According to the inventions of claims 2 to 6, since a plurality of diaphragm members are used, the degree of freedom in designing the aperture shape is large.

Since the inventions according to claims 4 to 6 are configured as described above, the degree of freedom in designing the aperture shape is large, and it is effective that the light reflected by the lens surface acts as stray light on the image forming portion. Can be reduced.

According to the fifth and sixth aspects of the invention, because of the above-mentioned structure, the degree of freedom in designing the aperture shape is large, and it is effective that the light reflected by the lens surface acts on the image forming portion as stray light. In addition to being reduced, the object side and the image side are spatially completely separated by the optical path separating mirror, so that an image with higher resolution and contrast can be formed.

[Brief description of drawings]

FIG. 1 is a diagram for explaining one embodiment of the invention according to claim 1;

FIG. 2 is a diagram showing two specific examples of diaphragm members.

FIG. 3 is a diagram for explaining one embodiment of the invention described in claims 2, 3 and 6.

FIG. 4 is a diagram for explaining another embodiment of the invention described in claims 2, 3 and 6.

FIG. 5 is a diagram for explaining one embodiment of the invention described in claims 2, 4, and 6.

FIG. 6 is a diagram for explaining another embodiment of the invention according to claims 2, 4, and 6;

FIG. 7 is a diagram for explaining two examples of the invention according to claims 5 and 6;

FIG. 8 is a diagram for explaining a conventional technique and its problems.

[Explanation of symbols]

1 lens array 2A diaphragm member 3 Roof mirror array

Claims (6)

(57) [Claims] 1. A lens array in which a series of optically equivalent lenses are arrayed in a row, and a series of roof mirrors having a ridge line orthogonal to the lens array direction and the lens optical axis direction in the lens array. A roof mirror array formed by arraying the lenses in the lens array in a 1: 1 relationship with the individual lenses in the lens array, and a diaphragm member that integrates the lens and the diaphragm member that separates the individual imaging systems from each other. In the mirror lens array, a roof mirror lens array, wherein the diaphragm member has a plurality of openings separated in the diaphragm member width direction for each lens. 2. A lens array in which a series of optically equivalent lenses is arrayed in one row, and a series of roof mirrors having a ridge line orthogonal to the lens array direction and the lens optical axis direction of the lens array. A roof mirror array in which each lens in the lens array is arrayed in a 1: 1 correspondence with each lens, and two or more diaphragm members for separating each image forming system by the lens and the roof mirror from each other. In an integrated roof mirror lens array, at least one of the two or more diaphragm members has a plurality of apertures separated in the diaphragm member width direction for each lens. Lens array. 3. The roof mirror lens array according to claim 2, wherein there are two diaphragm members, both of which are arranged between the lens array and the roof mirror array. 4. The roof mirror lens array according to claim 2, wherein the number of diaphragm members is two, and the roof mirror lens array is arranged so as to sandwich the lens array. 5. The roof mirror lens array according to claim 4, wherein an optical path separating mirror for separating an optical path from the object side and an optical path to the image side is provided on the side opposite to the roof mirror array with respect to the lens array. A roof mirror lens array characterized by being integrated with a diaphragm member. 6. The roof mirror lens array according to claim 3, 4 or 5, wherein one diaphragm member has one opening corresponding to each lens.