Lens array fabrication method, and film containing base plate and film attaching instrument employed in same

Abstract

A film attaching jig (III) is used in a method for fabricating a lens array to attach a pressure-sensitive adhesive optical film (D) onto an adhesion area (i) and has: (1) a main body having a first end face in a z′-direction being an end face to be directed to a film-containing base plate (II) and a lens array main unit (I); (2) a film holding projection that is provided on the first end face and protrudes in parallel to the z′-direction toward the film-containing base plate (II) and the lens array main unit (I), the film holding projection having a holding area (iii) at its front end face for temporarily holding the pressure-sensitive adhesive optical film (D); and (3) a pair of pins or holes disposed on the first end face in parallel to the z′-direction, and provided at opposite positions over the film holding projection.

1 . A film attaching jig (III) for use in a lens array fabrication method for fabricating a lens array,
 the lens array including a lens array main unit (I) and a pressure-sensitive adhesive optical film (D),   the lens array main unit (I) including:   a first surface and a second surface spaced from each other in an optical axis direction (hereinafter referred to as a z-direction);   a plurality of lens surfaces formed and aligned on the first surface along a predetermined alignment direction which is perpendicular to the z-direction (hereinafter referred to as a x-direction);   a planar optical plane on the second surface, through which light that has passed the plurality of lens surfaces is to pass, the planar optical plane defining a predetermined central area of the second surface that encompasses an entire projected region, the projected region being formed on the second surface when the lens surfaces are projected from the z-direction on the second surface, a surrounding area being defined on the second surface around the predetermined central area, the optical plane being defined by a recess that is concave relative to the surrounding area and depressed toward the lens surfaces, the optical plane extending in a direction perpendicular to the z-direction; and   a pair of first guide holes or guide pins that are disposed on opposite sides over the optical plane in the x-direction on the surrounding area of the second surface, the pair of first guide holes or guide pins extending parallel to the z-direction, an adhesion area (i) being defined, which contains part of the projected region for at least part of the plurality of lens surfaces, on the optical plane of the lens array main unit (i), the pressure-sensitive adhesive optical film (D) being attached on the adhesion area (i) by an adhesive force of the pressure-sensitive adhesive optical film itself,   the lens array fabrication method comprising, as a prerequisite step:   preparing a film-containing base plate (II) that contains the pressure-sensitive adhesive optical film (D), the film-containing base plate (II) having a base plate main element (A), the base plate main element (A) having a placement area (ii) on a first face of the base plate main element (A) in a z″-direction that corresponds to the z-direction, the placement area (ii) corresponding to the adhesion area (i), with a bonding layer (B), a non-adhesive first detachment film (C), the pressure-sensitive adhesive optical film (D), a non-adhesive second detachment film (E), and an adhesion layer (F) being stacked on the placement area (ii) in this order from the placement area (ii), a first peel strength f (C)-(D)  between the first detachment film (C) and the pressure-sensitive adhesive optical film (D) being smaller than a second peel strength f (D)-(E)  between the pressure-sensitive adhesive optical film (D) and the second detachment film (E), a pair of second guide holes or guide pins, which correspond to the pair of first guide holes/guide pins respectively, being provided in a region outside the placement area (ii) on the first face of the base plate main element (A), the second guide holes or guide pins being disposed on opposite sides over the placement area (ii) in a x″-direction, which corresponds to the x-direction, and the second guide holes or guide pins being parallel to the z″-direction;
 said film attaching jig (III) being adapted to attach the pressure-sensitive adhesive optical film (D) onto the adhesion area (i), said film attaching jig (III) having a main body, the main body having a first end face in a z′-direction which corresponds to the z-direction, the first end face of the jig main body being an end face to be directed to the film-containing base plate (II) and the lens array main unit (I), the jig (III) having a film holding projection that is provided on the first end face of the jig, the film holding projection protruding in parallel to the z′-direction toward the film-containing base plate (II) and the lens array main unit (I), the film holding projection having a holding area (iii) at its front end face, and the holding area (iii) corresponds to the adhesion area (i) and the placement area (ii), the holding area (iii) being configured to be able to temporarily hold the pressure-sensitive adhesive optical film (D) when the film holding projection work together with the film-containing base plate (II) and the lens array main unit (I), the jig (III) also having a pair of pins or holes disposed on the first end face of the jig main body in parallel to the z′-direction, the pair of pins or holes being provided at opposite positions over the film holding projection in a x′-direction which corresponds to the x-direction, the pair of pins or holes of the jig (III) corresponding to the pair of first guide holes/guide pins respectively and also corresponding to the pair of second guide holes/guide pins respectively. 
   
     
     
         2 . The film attaching jig (III) according to  claim 1 , wherein the optical plane of the lens array main unit (I) has a rectangular shape, when viewed in the z-direction, having a long side in the x-direction and a short side in a direction perpendicular to the x-direction and z-direction (hereinafter referred to as a y-direction),
 wherein the front end face of the film holding projection of the film attaching jig (III) has a rectangular shape, when viewed from the z′-direction, having a long side in the x′-direction and a short side in a y′-direction, the y′-direction being perpendicular to the x′-direction and the z′-direction,   the lens array main unit (I), the film-containing base plate (II) and the film attaching jig (III) satisfy conditional expressions (1) to (4) in the y-direction, the y′-direction, and the y″-direction:   the y-direction, the y′-direction and the y″ direction:
     a 1+Δ y>a 1′+Δ y′≧b″+Δy″   (1)
 
     a 2+Δ y>a 2′+Δ y′≧|a″−b″|+Δy″   (2)
 
     b″+Δy″>b 1+Δ y   (3)
 
   | a″−b″|+Δy″>|b 1− b 2|+Δ y   (4)
 
   the lens array main unit (I), the film-containing base plate (II) and the film attaching jig (III) satisfy conditional expressions (5) to (8) in the x-direction, the x′-direction, and the x″-direction:
     c 1+Δ x>c 1′+Δ x′≧d″+Δx″   (5)
 
     c 2+Δ x>c 2′+ Ax′≧|c″−d″+Δx″   (6)
 
     d″+Δx″>d 1+Δ x   (7)
 
   | c″−d″|+Δx″>|d 1− d 2|+Δ x   (8)
 
   where parameters of the conditional expressions (1) to (8) for the lens array main unit (I) are:   a1: distance in the y-direction from the center position of the optical plane in the y-direction to a first long side of the optical plane, which defines an outer circumference of the optical plane and extends along the x-direction,   a2: distance in the y-direction from the center position of the optical plane in the y-direction to an opposite long side of the optical plane, which defines the outer circumference of the optical plane on an opposite side of the first long side,   b1: distance from the center position of the optical plane in the y-direction to a distal end of said part of the projected region for said at least part of the plurality of lens surfaces in the y-direction,   b2: dimension of said part of the projected region for said at least part of the plurality of lens surfaces in the y-direction,   c1: distance in the x-direction from the center position of the optical plane in the x-direction to a first short side of the optical plane, which defines the outer circumference of the optical plane and extends along the y-direction,   c2: distance in the x-direction from the center position of the optical plane in the x-direction to an opposite short side of the optical plane, which defines the outer circumference of the optical plane on an opposite side of the first short side,   d1: distance from the center position of the optical plane in the x-direction to a distal end of said part of the projected region for said at least part of the plurality of lens surfaces in the x-direction,   d2: dimension of said part of the projected region for the said at least part of the plurality of lens surfaces in the x-direction,   Δy: sum of a position tolerance of each said lens surface in the y-direction with the centers of the first guide holes/guide pins being the reference, diameter tolerance of each said lens surface in the y-direction, and dimension tolerance of the optical plane in the y-direction,   Δx: sum of a position tolerance of each said lens surface in the x-direction with the centers of the first guide holes/guide pins being the reference, diameter tolerance of each lens surface in the x-direction, and dimension tolerance of the optical plane in the x-direction,   parameters of the conditional expressions (1) to (8) for the film attaching jig (III) are:   a1′: distance in the y′-direction from a center position of the front end face of the film holding projection in the y′-direction to a first long side of the front end face, which defines an outer circumference of the front end face and extends along the x′-direction,   a2′: distance in the y′-direction from the center position of the front end face of the film holding projection in the y′-direction to an opposite long side of the front end face, which defines the outer circumference of the front end face on an opposite side of the first long side,   c1′: distance in the x′-direction from the center position of the front end face of the film holding projection in the x′-direction to a first short side of the front end face, which defines the outer circumference of the front end face and extends along the y′-direction,   c2′: distance in the x′-direction from the center position of the front end face of the film holding projection in the x′-direction to an opposite short side of the front end face, which defines the outer circumference of the front end face on an opposite side of the first short side,   Δy′: dimension tolerance of the front end face of the film holding projection in the y′-direction with the centers of the pins/holes being the reference,   Δx′: dimension tolerance of the front end face of the film holding projection in the x′-direction with the centers of the pins/holes being the reference, and   parameters of the conditional expressions (1) to (8) for the film-containing base plate (II) are:   a″: dimension of the stacked elements (B) to (F) on the placement area (ii) in the y″-direction,   b″: distance in the y″-direction from the second hypothetical line segment to a distal end of the stacked elements (B) to (F) in the y″-direction,   c″: dimension of the stacked elements (B) to (F) in the x″-direction,   d″: distance in the x″-direction from a vertical bisector, which equally divides the second hypothetical line segment and extends in parallel to the y″-direction, to a distal end of the stacked elements (B) to (F) in the x″-direction,   Δy″: dimension tolerance of the stacked elements (B) to (F) in the y″-direction with the centers of the second guide holes/guide pins being the reference, and   Δx″: dimension tolerance of the stacked elements (B) to (F) in the x″-direction with the centers of the second guide holes/guide pins being the reference.