JP2003202411A - Resin erect lens array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin erect lens array for a linear scanning optical system, applicable to an image transmission device such as an optical printer or a scanner. <P>SOLUTION: Spherical or aspherical microlenses are densely and regularly arranged at a prescribed pitch on a resin lens plate manufactured by injection- molding, and the microlenses are arranged having a dense structure of a square (diamond) pattern. At a boundary part between respective microlenses, a groove or a projection is formed along the bisector 22 of a segment drawn between the centers of the microlenses, and a light absorbing film 24 is formed on the groove or the projection. Since a partitioning wall for partitioning an image forming space of adjacent lenses is formed in the groove or the projection part, stray light is effectively removed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin formed by arranging at least two resin lens plates in which microscopic lenses having spherical or aspherical surfaces are regularly arranged on a flat plate at a predetermined pitch. The present invention relates to an erecting lens array, and more particularly to a resin erecting lens array applicable to an image transmission device for a writing or reading optical system.

[0002]

2. Description of the Related Art Conventionally, a gradient index rod lens array has often been used in an image forming optical system used in an image transmitting apparatus for a writing optical system such as an optical printer or a reading optical system such as a scanner. With this lens array, an erecting equal-magnification imaging optical system can be realized in an extremely compact manner. However, since this lens array is manufactured by arranging a large number of rod lens elements and fixing them with resin, unevenness in the arrangement of the lens elements is likely to occur. Such array unevenness affects the resolution of the lens array, and is a cause of image unevenness or the like in a recent device having a higher resolution (for example, a resolution of 1200 dpi).

[0003]

In order to suppress the occurrence of such array unevenness, it has been considered to use a resin erect lens array instead of the rod lens array. The resin erecting lens array realizes an erecting equal-magnification imaging optical system by stacking two or more flat plate type lens array plates in which a large number of lenses are formed on a transparent substrate. Since the lens array plate on which the lenses are formed is manufactured by injecting the resin into the mold, there is no possibility that the lenses have irregular arrangement.

However, until now, such a resin erecting lens array has been used in combination with a liquid crystal display element to form a liquid crystal image on a space or an object. In order to apply it to a printer or a scanner, it is necessary to improve the resolution and the amount of transmitted light and reduce stray light. In addition to that,
For a so-called line scanning optical system, it is necessary to make the shape long.

An object of the present invention is to provide a resin erecting lens array applicable to an image transmitting device for a writing optical system such as an optical printer or a reading optical system such as a scanner.

[0006]

SUMMARY OF THE INVENTION The present invention is a rectangular plate having lens forming regions in which spherical or aspherical microlenses are regularly arranged at a predetermined pitch on both sides and central portion of the plate. The resin lens plate is characterized in that a region where no lens is formed is provided in a plate peripheral portion outside the lens formation region.

The minute lenses are arranged in a square or hexagonal arrangement in the plane direction of the plate, and the direction in which the distance between the centers of the adjacent minute lenses is the largest is parallel to the long side of the plate. Is desirable, and
It is desirable that they are arranged in a dense structure.

It is desirable that a resin injection gate mark at the time of injection molding is provided on one long side surface of the plate, and an assembling undercut is provided on the long side surface of the plate. .

It is preferable that a plurality of convex portions for adjusting the lens interval are provided along the long side of the plate in the area outside the lens forming area, and the plate is formed in the area outside the lens forming area. It is desirable that an adhesive portion having a height equal to or less than the height of the minute lens is provided along the long side.

Further, a convex portion is provided on one surface of both longitudinal end portions of the plate, and a concave portion is provided at the same position on the other surface, and the height of the convex portion is smaller than the depth of the concave portion, Further, it is desirable that the convex portion and the concave portion have similar shapes so that they can be fitted to each other, and it is desirable that cutout portions are provided at both ends in the longitudinal direction of the plate.

Further, it is desirable that a groove or a ridge is formed along a bisector of a line segment connecting the centers of the minute lenses, and a light absorbing film is formed on the groove or the ridge. The light absorbing film formed on the groove is preferably made of black ink guided to the groove by utilizing a capillary phenomenon.

Further, it is desirable that a transparent conductive film is formed on the plate surface so that the potential of the transparent conductive film can be adjusted.

Further, the present invention is a resin erecting lens array characterized by combining two or more of the above resin lens plates.

On the incident side and / or the exit side, in order to remove stray light, it is desirable to provide a partition structure which is formed substantially parallel to the optical axis of the lens as a partition for partitioning the imaging space of the adjacent lens. It is preferable that the partition structure is a structure in which a plurality of flat thin plates are arranged at equal intervals in parallel to the optical axis direction of the lens and perpendicular to the lens array longitudinal direction.

Further, it is desirable to provide a transmission viewing angle limiting means on the incident side and / or the emission side to remove stray light, and the transmission viewing angle limiting means selectively selects incident light outside a specific angle range. It is preferable that the light control film is a light control film that scatters or absorbs light, and the light control film is arranged so that the direction in which the viewing angle is limited is the lens array longitudinal direction.

Further, the protrusion pin mark formed by the pin protruding from the mold at the end of the injection molding provided on the surface of the resin lens plate and the resin injection gate mark which is the injection mark of the injection molding resin are in the same direction. It is desirable to stack a plurality of resin lens plates.

According to the present invention, the resin erecting lens array described above is housed in a housing, and the width of the housing is equal to or narrower than the width of the lens forming area in the sub-scanning direction along the main scanning direction. An image transmitting device for a writing or reading optical system, characterized in that the slit is provided.

It is preferable that a conductive film is formed on at least the surface of the casing so that the potential of the conductive film can be adjusted.

Further, it is desirable that the slit is covered with a translucent member, and the resin erect lens array has an undercut portion provided around the resin lens plate and a protrusion provided on the housing. It is desirable to fit and to be housed in the housing.

Further, the slit is covered with a light control film that selectively scatters or absorbs incident light outside a specific angle range, and the light control film is arranged so that the direction in which the viewing angle is limited becomes the main scanning direction. It is desirable to arrange.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view and a side view of a resin lens plate which constitutes a resin erecting lens array according to the present invention. The resin lens plate is manufactured by injection molding. A convex lens is formed on both sides of the resin lens plate, and the resin erecting lens array according to the present invention is shown in FIG.
Two or more resin lens plates shown in FIG.

The material of the resin lens plate is an injection moldable resin, particularly an olefin resin, a cycloolefin resin or a norbornene resin. Examples of commercially available resins include ZEONEX (registered trademark) and ZEONOR (registered trademark) manufactured by ZEON CORPORATION, and ARTON (registered trademark) manufactured by JSR Corporation. It is characterized by low water absorption.

The resin lens plate 10 manufactured by injection molding has a long rectangular shape, and a lens forming area at the center portion thereof corresponds to the longitudinal direction of the resin lens plate 10 (corresponding to the main scanning direction of the image transmission device). ), A large number of spherical or aspherical microlenses 12 are arranged, and a plurality of rows of spherical or aspherical microlenses 12 are arranged in a direction (sub-scanning direction) orthogonal to the longitudinal direction.

In addition to the lens forming area, a plurality of lens-interval adjusting convex portions 14 having a height equal to or higher than the lens height are formed in order to keep the distance between the facing minute lens vertices constant. The convex portion 14 for adjusting the lens interval is preferably formed along the long side of the resin lens plate 10 in order to prevent the resin lens plate 10 from bending in the longitudinal direction.

Further, a plurality of ejection pin marks 16 of the injection molding machine are formed outside the lens forming area. This is an indentation made by a pin that projects the molded body from the mold in order to facilitate mold release at the end of injection molding.

On the side surface in the longitudinal direction of the resin lens plate 10 (the surface on which the lens is not formed), a film gate mark portion 18 which is an injection gate mark of the injection molding resin can be seen. In the case of a long thin rectangular molded body, if a wide film gate is provided on the side surface in the longitudinal direction and molding is performed by injecting resin from this, molding shrinkage occurs uniformly, so there is little deformation and the molded body Internal stress is reduced.

An undercut portion 20 for assembly is provided on the side surface of the resin lens plate 10.
The undercut portion 20 and the convex portion provided on the external housing are fitted to each other to facilitate the assembly into the external housing. In order to fix the long resin lens plate 10, it is desirable to provide the undercut portion 20 on the longitudinal side surface of the resin lens plate.

As shown in FIG. 2, the spherical or aspherical microlenses 12 are arranged in a staggered arrangement in which the lenses are staggered with respect to the outer periphery of the resin lens plate. The shape of the lens in the plate plane direction is shown in FIG.
There is a case of a quadrangle shown in FIG. 2A and a case of a hexagon shown in FIG. 2A shows a state where the lenses are densely arranged in a square array, and FIG. 2B shows a state where the lenses are densely arranged in a hexagonal array. The quadrangle need not be a square as shown, but can be selected from parallelograms including rhombuses and rectangles. The hexagon is not limited to a regular hexagon as long as the opposite sides are parallel.
It should be noted that any of the lens arrangements does not necessarily have to have a dense structure, and may have a non-dense structure having a gap between the lenses. However, the dense structure is superior in terms of the amount of transmitted light.

When such a lens array is used for a line scanning optical system, as shown in FIG. 3, the longitudinal direction of the lens array, that is, the main scanning direction of the line scanning optical system is the most center distance between the minute lenses. It is preferable to select so as to match in a large direction.

This is for the following reason. Figure 3
In the case of the square array lens array shown in FIG.
The stray light 83 generated at the position of the closest lens 82 in the four directions has the highest intensity with respect to the imaged light ray 81 of 0. In this case, the influence of the stray light 83 on the imaging light ray 81 is reduced by arranging the main scanning direction in the arrow direction in the drawing, that is, in the direction parallel to the diagonal line of the square in which the distance between the centers of the adjacent lenses is the largest. be able to.

Similarly, in the case of the hexagonal lens array of FIG. 3B, the intensity of the stray light 93 generated at the position of the closest lens 92 in the six directions is the highest with respect to the imaging light ray 91 of the lens 90. large. Also in this case, the influence of the stray light 93 on the imaging light ray 91 can be reduced by arranging the main scanning direction in the arrow direction in the figure, that is, in the direction in which the distance between the centers of the adjacent lenses is maximized.

In the case of the arrangement described above, in the case of a square array lens, the distance between the stray light generation position and the scanning line can be made larger than in the case of the hexagonal array, so that the effect of stray light is small. . It should be noted that any of the above arrangements can be a dense structure arrangement as shown in FIG. In this case, the minute lens is a square lens or a hexagonal lens, and as described above, the square lens is more advantageous in terms of the influence of stray light. However, the hexagonal lens has a feature that the aberration in the lens peripheral portion is smaller and the transmitted light amount is larger than the square lens.

A low reflection coating is formed on the surface of the molded resin lens plate 10. The low reflection coating is
This is for reducing the reflectance of the resin lens plate, and a fluorine resin film is used.

A transparent conductive film may be formed on the surface of the resin lens plate. By forming a transparent conductive film on the surface of the resin lens plate and adjusting the potential of the transparent conductive film, it is possible to prevent the resin lens array from being charged and foreign matter such as toner from adhering to the lens surface. In this case, it is most preferable to adjust the potential of the transparent conductive film so that it is at the same potential as the photoconductor to which the toner adheres by the exposure / development process.
When an ITO (indium oxide-tin) film is used as the transparent conductive film, it can also serve as a hydrophilic film. The hydrophilic coating improves the wettability with respect to the adhesive.

Further, on the surface of the low reflection coating formed on the resin lens plate, a light absorbing film for removing stray light is formed at the boundary portion between the adjacent minute lenses.

FIG. 4 is a partial plan view showing an example in which a light absorbing film is formed. FIG. 4A shows that the light-absorbing film 2 is formed in a region of a constant width along the bisector 22 of the line segment connecting the centers of the lenses.
4 shows the case in which the openings 4 are formed to form the openings 4.
In this case, it is preferable that the lens is grooved or ridged along the bisector 22, and the light absorbing film 24 is formed thereon. This groove or ridge acts as a partition between the lenses, and can block a part of the light ray inclined with respect to the optical axis.

FIG. 4B shows an opening 2 concentric with the lens.
The case where the light absorbing film 24 is formed in a region other than 6 is shown.

In the case where the lens is grooved or projected along the bisector 22 and the light absorbing film 24 is formed thereon, an image of an adjacent lens is formed in the grooved or projected portion. Since the partition wall that divides the space is formed, stray light can be removed more effectively than in the case where the light absorbing film 24 is formed in a region other than the opening 26 that is concentric with the lens, as shown in FIG.

FIG. 5 is a sectional view taken along the line AA 'in FIG. As shown in FIG. 5A, a light-absorbing film 24 is formed in a portion other than the boundary portion of the microlenses and the lens forming area, leaving the opening 26. Also, FIG.
(B) shows the case where a groove is formed in the lens along the bisector and the light absorbing film 24 is formed on the groove.

In FIG. 6, a groove is formed on one surface of the resin lens plate along the bisector connecting the centers of the lenses, and the other surface is projected along the bisector connecting the centers of the lenses. It is a figure which shows the state which laminated | stacked the resin lens plate by which the strip | belt processing was given. FIG. 6A shows a partial plan view of a groove formed on one surface of the resin lens plate.
6B is a partial cross-sectional view when two resin lens plates are stacked, and FIG. 6C is a partial plan view of a protrusion formed on the other surface of the resin lens plate. Is shown. The groove and the ridge have a shape capable of fitting with each other. As described above, when the groove is formed on one surface of the resin lens plate 10 and the ridge is formed on the other surface, when the resin lens plates 10 are stacked to form the resin erect lens array, the groove is formed. By fitting the protrusions, stray light can be removed and alignment can be performed.

Further, FIG. 7A shows a partial plan view of the grooves formed on both surfaces of the resin lens plate.
(B) is a partial cross-sectional view showing a case where two resin lens plates having grooves formed on both surfaces are laminated. In this way, when grooves are formed on both surfaces of the resin lens plate 10 along the bisector that connects the centers of the lenses, when the resin lens plates 10 are stacked to form a resin upright lens array, the grooves are formed. By inserting the light shielding wall 23 having a thickness equal to or less than the groove width to the stray light, stray light can be removed and alignment can be performed.

Here, a method of forming the light absorbing film on the groove formed along the bisector connecting the centers of the lenses will be described.

FIG. 8 is a diagram for explaining an example of a method of forming a light absorbing film on the groove. As shown in FIG. 8, an ink reservoir 27 deeper than the groove is formed along the long side of the resin lens plate 10 outside the lens formation region, and the black ink 25 is dropped there. Then, the resin lens plate 10 is tilted in the direction of the short side to cause the black ink 25 to flow, and the black ink 25 is guided to the groove between the lenses by utilizing a capillary phenomenon to form a light absorbing film.

FIG. 9 is a view for explaining another example of the method of forming the light absorbing film on the groove. As shown in FIG. 9, a bank-shaped portion 29 may be provided outside the lens formation region along the long side of the resin lens plate 10, and ink may be dropped there.

FIG. 10 shows a partial shape of the light absorbing film formed on the resin lens plate by the method shown in FIGS. 8 and 9 and a partial sectional view of the resin lens plate. In FIG. 10, reference numeral 31 is an ink inflow position.

According to the above-mentioned method, steps such as printing and patterning for forming the light absorbing film are unnecessary.
The surface in the groove may be modified to improve the fluidity of the ink. Further, the viscosity of the ink, the diameter of the black particles, etc. are optimally selected.

The light absorbing film 24 is also formed on the resin lens plate shown in FIG. 4 in a region other than the lens forming region, through which light rays that do not contribute to image formation on the image plane are transmitted. Figure 4
At 28 is a lens boundary.

On the surface of the resin lens plate, a positioning marker 30 (the shape is not limited to a cross shape, but may be a square shape or the like) when the light absorbing film 24 is formed. Good.

The area other than the lens area of the resin lens plate, through which light rays that do not contribute to image formation on the image plane are transmitted, is
For the purpose of reducing reflection when the light absorbing film is formed, it is desirable to make it a rough surface or a minute uneven surface.

Further, when the material of the low reflection coating formed on the surface of the resin lens plate is fluorine resin, it is desirable that the material of the light absorbing film formed thereon is also fluorine resin. This is to improve the adhesion.

FIG. 11 is a view showing another example of the resin lens plate, showing a plan view and a side view of the resin lens plate and a sectional view taken along the line BB ′. In both end regions of the resin lens plate 10 in the longitudinal direction, in order to adjust the position when the two resin lens plates are overlapped with each other, the protrusions 34 and the recesses 36 having similar shapes fitted to each other are fitted.
Are provided on both sides of the resin lens plate.

In addition, for the purpose of aligning two or more resin lens plates, several holes are formed on the same surface as the lens surface of the resin lens plate other than the lens forming area, an uneven portion for fitting, or a side surface. You may make it provide the uneven part for centering.

FIG. 12 is a view showing still another example of the resin lens plate, showing a plan view and a side view of the resin lens plate and a sectional view taken along the line CC ′. Alignment V-shaped notches 38 for aligning the resin lens plates are provided in both end regions of the resin lens plate 10 in the longitudinal direction.

In FIGS. 11 and 12, a bonding portion 32 for bonding the resin lens plates to each other is provided outside the lens forming region of the resin lens plate 10 along the long side. Concavo-convex grooves are formed in the bonding portion 32 in order to increase the bonding area as compared with the case where flat surfaces are bonded to each other.

Although the convex portion 14 for adjusting the lens interval shown in FIG. 1 is not shown in FIGS. 11 and 12, it may be formed between the adhesive portion 32 and the lens forming region.

In the resin erect lens array according to the present invention, at least two resin lens plates are superposed, the optical axes of the minute lenses of the resin lens plates are aligned, and the resin lens plates are bonded and fixed to each other. Formed.

FIG. 13 is a side view of a resin erecting lens array formed by stacking three resin lens plates 10 shown in FIG.

At the time of stacking, the protruding pin traces 16 and the film gate traces 18 at the time of molding shown in FIG. 1 are used for alignment. By aligning the protrusion pin traces 16 and the film gate traces 18 so that they are in the same direction and overlapping the resin lens plates, a combination in which the molding directions are the same can be easily obtained.

When superposing two resin lens plates, first, a simple alignment is performed. In the case of the resin lens plate shown in FIG. 11, the formed convex portion 34 and concave portion 3
The position can be adjusted by fitting 6 together. In the case of the resin lens plate of FIG. 12, the position can be adjusted by fitting a V-shaped notch between a pair of rigid cylindrical jigs. Positioning of a long resin lens plate
It is desirable to fix the position at both ends in the longitudinal direction because the positional deviation easily occurs in the longitudinal direction. Notch is not always V
It does not need to be U-shaped, but may be U-shaped or the like.

14 and 15 are a side view and a plan view of the resin lens plate before and after the alignment when the resin lens plates shown in FIG. 12 are superposed and aligned.

As shown in FIG. 14, the resin lens plates shown in FIG.
When the resin lens plate 10 is bent when positioning is performed by fitting a notch between
As shown in FIG. 3, through holes are provided at both ends in the longitudinal direction of the long resin lens plate, the rod-shaped jigs 35 are inserted therein, and tension is applied in the longitudinal direction for alignment.

FIG. 16 is a diagram showing another example of alignment when the resin lens plates are overlapped. FIG.
FIG. 16A is a cross-sectional view of the superposed resin lens plates, and FIG. 16B is an enlarged view of portion E of FIG. 16A. At one end of the long resin lens plate 10 in the short side direction, one semi-cylindrical (chamber-shaped) convex portion 39 is provided on one surface of the resin lens plate 10, and two semi-cylindrical projections are provided on the other surface. When the resin lens plates 10 are overlapped with each other by providing the convex portion 40
Positioning is performed by fixing the two semi-cylinders so that the side surfaces of the one semi-cylinder are in contact with each other.

As shown in FIG. 6, when the resin lens plates are superposed on each other, a groove is formed on one surface of the resin lens plate along the bisector connecting the centers of the lenses. The alignment may be performed by processing the other surface along a bisector connecting the centers of the lenses and fitting the groove into the projection.

Further, as shown in FIG. 7, grooves are formed on both sides of the resin lens plate along the bisector connecting the centers of the lenses, and when the resin lens plates are superposed on each other, the grooves are formed between the plates. The alignment may be performed by sandwiching a light shielding wall having a thickness equal to or less than the groove width.

Further, the resin lens plate may be housed in a band-shaped or plate-shaped structure having an inner size larger than the outer size of the resin lens plate for alignment or fixing. Further, a resin lens plate composed of two or more sheets is formed by pressing and fixing an abutting pin on the long side opposite to the film gate mark portion and pressing from the opposite side having the film gate mark portion by a spring or the like. It is also possible to perform alignment between them.

Bonding between the resin lens plates is performed by applying an adhesive to the bonding portion 32 shown in FIG. 11 or 12.

If a sufficient adhesive force cannot be secured between the resin lens plates by bonding with the bonding portion 32, the adhesive is applied to the concave and convex fitting portions other than the lens forming area of the resin lens plates to bond the resin lens plates to each other. Glue. For example, the convex portion 34 and the concave portion 36 shown in FIG.

When the resin lens plates can be mechanically fixed by bonding only the concave-convex fitting portion, the concave-convex fitting portion alone may be fixed.

The material of the adhesive is similar to the film coated on the resin lens plate. For example, when the material of the low reflection coating formed on the surface of the resin lens plate is a fluororesin and the material of the light absorbing film formed thereon is also a fluororesin, the adhesive material is also a fluororesin. Is desirable. This is to improve the adhesion.

When the two resin lens plates facing each other are bonded and fixed, an adhesive having a curing shrinkage is used to maintain contact between the lens vertices. The adhesive portion 32 has a height equal to or less than the height of the lens, and when the adhesive contracts, the interval between the resin lens plates is determined by the abutting of the lens interval adjusting protrusions shown in FIG. It When the convex portion for adjusting the lens interval is not formed, the interval between the resin lens plates is determined by the contact of the tops of the lenses. Further, a photo-curable adhesive is used as the adhesive. This is because an adhesive that is hardened by heating is not desirable because it is displaced due to deformation when it is fixed after alignment.

Further, the resin lens plates may be bonded to each other by ultrasonic welding instead of using an adhesive agent for bonding the resin lens plates. FIG. 17 (a) is a plan view of a resin lens plate adhered using ultrasonic welding,
FIG. 17B is a side view of the long side, and FIG.
[Fig. 6] is a sectional view taken along line GG '.

Further, FIG. 18A is an enlarged cross-sectional view of the F portion of FIG. 17C, which is a bonded portion region of the resin lens plate, before and after bonding. In this case,
As shown in FIG. 8 (a), a steeply inclined triangular protrusion 41 is provided in the adhesive portion region of one resin lens plate, and a gently inclined triangular concave portion 42 is provided in the opposing adhesive portion region of the other resin lens plate, The triangular protrusions 41 are melted by applying ultrasonic waves, and the resin protrusions 41 are bonded to each other by forming the triangular protrusions 41 into a triangular shape that fits the triangular recesses 42.

FIG. 18 (b) is an enlarged cross-sectional view of the resin lens plate in both longitudinal end regions before and after bonding. The height of the convex portion 43 formed in both end regions in the longitudinal direction is set to be slightly higher than the depth of the concave portion 45, and ultrasonic waves are applied to the convex portion 43 to melt the convex portion 43 so that the convex portion 43 has the shape of the concave portion 45. Adhere the resin lens plates to each other so that

When the resin lens plates are adhered to each other by ultrasonic welding, a hydrophilic film forming step and an adhesive applying step are not necessary.

The resin lens plates are provided with through holes at several places other than the lens forming area of the resin lens plate for the purpose of mechanically fixing the resin lens plates facing each other.
The welding pin may be inserted and fixed by welding, or in order to mechanically fix the opposing resin lens plate, an uneven portion is provided so that the clip does not come off other than the lens forming area of the resin lens plate, and the You may fix it.

When the resin lens plates are superposed on each other, a film for removing stray light may be sandwiched between the resin lens plates.

This film has a large optical transmittance and is provided with a light-absorbing print provided with openings on the surface of the film, the openings being substantially aligned with the lens array pitch, or a small optical transmittance. A lens provided with an aperture that substantially matches the lens arrangement is used.

On the incident side and / or the emitting side of the resin erecting lens array formed by laminating resin lens plates, partition walls for partitioning image forming spaces of adjacent lenses are formed in order to remove stray light. The partition structure may be provided so as to be substantially parallel to the optical axis of the lens.

FIG. 19 (a) is a side view of the resin erect lens array showing a state in which the partition wall structure 44 is provided on the incident side of the resin erect lens array, and FIG. 19 (b) is an incident side. FIG. 3 is a side view of the resin erecting lens array showing a state in which the partition wall structure 44 is provided on the exit side.

In the line scanning optical system for the image transmission device, only the stray light inclined in the longitudinal direction, that is, the main scanning direction becomes a problem. Therefore, the partition wall structure 44 may have a light blocking function in the longitudinal direction of the resin erect lens array.

As an example of such a partition structure 44,
There is a interdigital structure in which thin plates are arranged in parallel in the vertical direction at equal intervals. As the thin plate, a thin plate made of metal or resin, which has been subjected to antireflection treatment such as forming a light absorbing coating on the surface, is used.

As another example, means for limiting the transmission viewing angle in the longitudinal direction of the resin erecting lens array can be used. A light control film that selectively scatters or absorbs incident light outside the specific angle range is arranged such that the direction in which the viewing angle is limited is the longitudinal direction of the lens array. The light control film is produced by stacking and adhering a transparent resin and a light absorbing resin, and slicing to a predetermined thickness in a direction perpendicular to the stacking direction. However, the present invention is not limited to this, and may be, for example, a resin film containing molecules oriented in a certain direction such as oriented liquid crystal.

FIG. 20 is a diagram showing a state in which the resin erecting lens array is housed in the housing of the image transmitting device for the writing or reading optical system. The resin upright lens array is
The undercut portion provided around the resin lens plate and the protrusion provided on the housing are fitted to each other and housed in the housing. By covering the periphery of the resin erecting lens array with a housing, it is possible to suppress light rays and ambient light that pass from the object point (light source), pass through the lens, and do not contribute to the image formation of the image point. The inner wall of the housing is light-absorbing treated.

Further, in order to remove a light ray which does not contribute to the image formation of the image point from the object point and which passes through the lens, as shown in the plan view of FIG. Body 46
A slit (or aperture) 48 is provided between the lens and the image plane, especially along the main scanning direction. However, the width of the slit 48 is equal to or narrower than the width of the lens forming area (width in the sub-scanning direction).

The case 46 is made of a conductor such as metal,
Alternatively, it is preferable that a conductive film is formed on the surface of the housing 46 to impart conductivity, and the potentials of the conductor and the conductive film can be adjusted. By adjusting the potential and keeping it at the same potential as the photoconductor, it is possible to prevent the toner from being attracted and prevent the toner from adhering to the resin lens array.

The slit may be covered with a translucent member such as glass, or as shown in FIG.
An opening is provided in the housing 46 along the main scanning direction,
The opening may be covered with a translucent member 50 such as glass on which the slit 48 is printed. By covering the slits or openings with a transparent member, it is possible to prevent toner from adhering to the resin lens array.

Further, the resin erecting lens array may have partition wall structures on the incident side and / or the emitting side. Figure 2
0 (c) shows a state in which the light control film 52 is provided as a transmission viewing angle limiting means between the resin erecting lens array and the slit in order to block a light ray inclined in the main scanning direction. .

[0089]

As described above, since the resin lens array of the present invention is composed of the resin lens plate manufactured by injection molding, there is no risk of uneven arrangement of the lenses.

Further, in the present invention, since the partition wall for removing the stray light is formed around the minute lens, the stray light can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view and a side view of a resin lens plate that constitutes a resin erecting lens array according to the present invention.

FIG. 2 is a diagram illustrating the arrangement of minute lenses.

FIG. 3 is a diagram illustrating a preferred arrangement direction of microlenses.

FIG. 4 is a partial plan view showing an example in which a light absorbing film is formed.

5 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 6 is a diagram showing a state in which two resin lens plates each having a groove formed on one surface and a ridge processing on the other surface are stacked.

FIG. 7 is a diagram showing a state in which two resin lens plates having grooves formed on both sides are stacked.

FIG. 8 is a diagram illustrating an example of a method of forming a light absorbing film on a groove.

FIG. 9 is a diagram illustrating another example of the method of forming the light absorbing film on the groove.

FIG. 10 is a diagram showing the shape of a light absorbing film formed on a resin lens plate by the method shown in FIGS. 8 and 9.

FIG. 11 is a diagram showing another example of the resin lens plate.

FIG. 12 is a diagram showing still another example of the resin lens plate.

FIG. 13 is a side view of a resin erect lens array formed by stacking three resin lens plates.

14A and 14B are a side view and a plan view of the resin lens plate when the resin lens plates are overlapped with each other for alignment.

15A and 15B are a side view and a plan view of the resin lens plate when the resin lens plates are superposed and aligned with each other.

FIG. 16 is a diagram showing another example of alignment when superimposing resin lens plates.

FIG. 17 is a diagram showing a resin lens plate adhered by ultrasonic welding.

FIG. 18 is an enlarged side view of a bonding portion region before and after bonding.

FIG. 19 is a side view of the resin erecting lens array showing a state in which a partition structure is provided on the incident side and / or the emitting side.

FIG. 20 is a diagram showing a state in which a resin erecting lens array is housed in a housing.

[Explanation of symbols]

10 Resin lens plate 12 Micro lens 14 Lens interval adjustment convex part 16 protruding pin marks 18 Film gate marks 20 Undercut part 22 Bisecting line 23 Shading wall 24 Light absorbing film 25 black ink 26 opening 27 ink reservoir 28 lens boundary 29 Bank-shaped part 30 Positioning marker 31 Ink inflow position 32 Adhesive part 33 jig 34,43 convex 35 Rod jig 36,45 recess 38 V-shaped notch for centering 39,40 Semi-cylindrical protrusion 41 Triangular protrusion 42 triangular recess 44 Partition structure 46 housing 48 slits 50 translucent member 52 Light control film 80,90 lens 81,91 Imaging rays 82,92 Closest lens 83,93 stray light

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 13/24 H04N 1/036 A H04N 1/028 B29L 11:00 1/036 G02B 1/10 A // B29L 11:00 ZF term (reference) 2H042 AA03 AA10 AA11 AA13 AA29 2H087 KA19 LA21 PA03 PA17 PB03 UA01 2K009 AA04 BB11 CC06 DD02 EE00 EE03 4F202 AA03 A02 AA03 AA12 AG03 AH74 CA11 CK06 A02 A04 A02 A02 A02 A02

Claims (31)

[Claims] 1. A rectangular plate, comprising lens forming regions in which spherical or aspherical microlenses are regularly arranged at a predetermined pitch on both sides and central portion of the plate.
A resin lens plate comprising a region where no lens is formed in a plate peripheral portion outside a lens formation region. 2. The microlenses are arranged in a tetragonal array or a hexagonal array in the plate plane direction, and are arranged such that the direction in which the center distance between adjacent microlenses is the largest is parallel to the long side of the plate. The resin lens plate according to claim 1, wherein the resin lens plate is provided. 3. The resin lens plate according to claim 1, wherein the microlenses are arranged in a dense structure. 4. The resin lens plate according to claim 1, wherein a resin injection gate mark at the time of injection molding is provided on one long side surface of the plate. 5. An undercut for assembling is provided on a long side surface of the plate.
The resin lens plate according to any one of to 4. 6. A plurality of lens-interval adjusting convex portions are provided along a long side of the plate in an area outside the lens forming area, and the convex portion for adjusting the lens interval is provided. Resin lens plate. 7. An adhesive portion having a height equal to or less than the height of the minute lens is provided along a long side of the plate in an area outside the lens forming area. The resin lens plate according to any one of 1 to 6. 8. A plate is provided with a convex portion on one surface of both end portions in the longitudinal direction, and a concave portion is provided at the same position on the other surface, and the height of the convex portion is smaller than the depth of the concave portion. The resin lens plate according to any one of claims 1 to 7, wherein the convex portion and the concave portion have similar shapes so that they can be fitted to each other. 9. The resin lens plate according to claim 1, wherein notches are provided at both ends in the longitudinal direction of the plate. 10. A light absorbing film is formed on a boundary portion between the adjacent minute lenses.
9. The resin lens plate according to any one of 9 above. 11. A light absorbing film is formed in a region of a constant width along a bisector of a line segment connecting the centers of the minute lenses. The described resin lens plate. 12. A groove or a ridge is formed along a bisector of a line segment connecting the centers of the microlenses, and a light absorbing film is formed on the groove or the ridge. The resin lens plate according to any one of claims 1 to 9. 13. A light absorptivity comprising a black ink formed on the groove along a bisector of a line connecting the centers of the microlenses, the black ink being guided to the groove by utilizing a capillary phenomenon. The resin lens plate according to claim 1, wherein a film is formed. 14. A groove is formed on one surface of a plate along a bisector of a line segment connecting the centers of the minute lenses, and on the other surface, a bisector of a line segment connecting the centers of the minute lenses. 10. A ridge is formed along a line, the groove and the ridge are shaped so that they can be fitted to each other, and a light absorbing film is formed on the groove. The resin lens plate described in Crab. 15. The resin lens plate according to claim 14, wherein the light absorbing film is made of black ink guided to the groove by utilizing a capillary phenomenon. 16. A groove is formed on both sides of the plate along a bisector of a line segment connecting the centers of the minute lenses, and a light absorbing film is further formed on the groove. Item 10. A resin lens plate according to any one of items 1 to 9. 17. The resin lens plate according to claim 16, wherein the light absorbing film is made of black ink guided to the groove by utilizing a capillary phenomenon. 18. A transparent conductive film is formed on the plate surface,
The resin lens plate according to claim 1, wherein the potential of the transparent conductive film is adjusted. 19. A resin erecting lens array comprising two or more resin lens plates according to claim 1 in combination. 20. A resin upright lens array, characterized in that two or more resin lens plates according to claim 14 or 15 are assembled by combining the groove and the projection with each other. 21. A resin upright lens array comprising two or more resin lens plates according to claim 16 or 17, wherein a light shielding wall having a thickness equal to or less than the groove width is inserted into said groove. . 22. On the incident side and / or the exit side, a partition wall structure that is formed substantially parallel to the optical axis of the lens is provided as a partition wall for partitioning an imaging space of an adjacent lens in order to remove stray light. The resin upright lens array according to any one of claims 19 to 21. 23. The partition wall structure is a structure in which a plurality of flat plate-like thin plates are arranged at equal intervals in parallel to the optical axis direction of the lens and perpendicular to the lens array longitudinal direction. The resin upright lens array according to claim 22. 24. The resin erecting lens array according to claim 19, wherein a transmission viewing angle limiting means is provided on the incident side and / or the emitting side for removing stray light. 25. The transmission viewing angle limiting means is a light control film that selectively scatters or absorbs incident light outside a specific angle range, and the direction in which the viewing angle is limited is the lens array longitudinal direction. 25. The resin erecting lens array according to claim 24, wherein the light control film is disposed in the. 26. A protrusion pin mark formed by a pin protruding from a mold at the end of injection molding provided on the surface of a resin lens plate and a resin injection gate mark as an injection mark of injection molding resin are in the same direction, 20. A plurality of resin lens plates are overlapped with each other.
25. The resin upright lens array according to any one of items 25 to 25. 27. The resin erecting lens array according to any one of claims 19 to 26 is housed in a housing, and the width of the lens forming region in the sub-scanning direction is arranged along the main scanning direction in the housing. Image transfer device for writing or reading optics, characterized in that slits of equal or narrow width are provided. 28. The writing or reading optical system according to claim 27, wherein a conductive film is formed on at least the surface of the housing so that the potential of the conductive film can be adjusted. Image transmission device. 29. The image transmission device for a writing or reading optical system according to claim 27, wherein the slit is covered with a translucent member. 30. The resin upright lens array is housed in a housing by fitting an undercut portion provided around the resin lens plate and a projection provided on the housing. 30. An image transfer device for a writing or reading optical system according to claim 27. 31. The light control film, wherein the slit is covered with a light control film that selectively scatters or absorbs incident light outside a specific angle range, and the direction in which the viewing angle is limited is the main scanning direction. 31. The image transfer device for a writing or reading optical system according to claim 27, wherein: