JP2001056404A - Prism and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a color synthesizing prism having two dichroic surfaces and to make an optical characteristic excellent by arranging the dichroic films of two surfaces constituting the respective dichroic surfaces on an identical surface. SOLUTION: Four right-angled prisms 11, 12, 13 and 14 are stuck by interposing substrates 21, 22, 23 and 24 obtained by forming the dichroic films D1, D2, D3 and D4 at one surface so as to constitute the color synthesizing prism 10 for a liquid crystal projector device. The respective films D1 and D3 forming the identical dichroic surface Dr are formed at the mutually opposed surfaces of the substrates 21 and 23. Then, a guide jig is made to abut on projecting guide parts 21a and 23a projectingly formed at the upper and the lower sides of the substrates 21 and 23 so as to align the films D1 and D3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a prism for performing color synthesis in a liquid crystal projector, and a method of manufacturing the prism.

[0002]

2. Description of the Related Art Conventionally, for example, in a liquid crystal projector device, a desired image is projected by synthesizing a red color light R, a green color light G, and a blue color light B, each of which is light-modulated, into one light beam by a color synthesizing prism. A configuration for projecting onto a surface is known. The color synthesizing prism is also called a cross prism or a cross dichroic prism. For example, as shown in JP-A-10-332910, a wavelength-selective reflective Using four right-angle prisms that form a dichroic surface by directly evaporating the film, these right-angle prisms are bonded to each other with an adhesive with the right-angle surfaces facing each other, and formed into a rectangular parallelepiped. A cross-shaped dichroic surface is formed. Then, the respective color lights entering from the three side surfaces facing the dichroic surface of the color combining prism at an angle of 45 degrees are combined on the dichroic surface to form one light flux, and are emitted from the other one side surface portion. It has become.

Further, in the configuration disclosed in Japanese Patent Application Laid-Open No. Hei 10-332910, the position of each rectangular prism is shifted by the thickness of the wavelength-selective reflection film and the thickness of the adhesive, and the two types of wavelength selectivity are changed. With respect to the reflective films, the same wavelength-selective reflective films are positioned on the same plane.

[0004]

However, in the configuration in which the wavelength-selective reflection film is formed directly on the right-angle prism as in the above-mentioned conventional art, the right-angle prism which cannot form a wavelength-selective reflection film having desired characteristics cannot be formed. However, the right angle prism itself cannot be used as a color combining prism even if there is no defect, so that there is a problem that the manufacturing cost is increased. In addition, as for a configuration in which the same wavelength-selective reflection film is positioned on the same plane, a configuration that can improve the accuracy and improve the optical characteristics while improving the workability and reducing the manufacturing cost is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a prism and a method of manufacturing a prism which can reduce the manufacturing cost and improve the optical characteristics.

[0006]

According to a first aspect of the present invention, there is provided a prism comprising a plurality of prism elements having a bonding surface, an optical film substrate bonded between the bonding surfaces, and at least one surface of the optical film substrate. And a formed optical film.

In this configuration, since the optical film is formed not on the prism element but on the optical film substrate bonded to the prism element, when the formation of the optical film fails,
The loss of the optical film base is sufficient, and the manufacturing cost can be reduced as compared with the configuration in which the optical film is formed directly on the prism element.

According to a second aspect of the present invention, in the prism according to the first aspect, the optical film substrate is a glass plate;
The optical film is formed by vapor deposition on one surface of each optical film substrate.

In this configuration, when the deposition of the optical film fails, the loss of the glass plate is sufficient, and the manufacturing cost can be reduced.

According to a third aspect of the present invention, in the prism of the first or second aspect, the prism element is a right-angle prism, the optical film is a wavelength-selective reflective film, and the optical films are two surfaces orthogonal to each other. It constitutes a dichroic surface.

With this configuration, the manufacturing cost of a prism having two dichroic surfaces can be reduced.

According to a fourth aspect of the present invention, there is provided the prism according to the third aspect, further comprising two optical film bases provided with a wavelength-selective reflective film constituting one dichroic surface,
In these optical film substrates, a wavelength-selective reflection film is provided on a predetermined surface facing each other, and the predetermined surface is arranged flush.

In this configuration, the wavelength-selective reflection film formed on the optical film substrate is easily arranged flush with the predetermined surface as a reference, and the optical characteristics are improved. In addition, the wavelength-selective reflecting film is easily and continuously arranged also at a portion where the two dichroic surfaces intersect, and the optical characteristics are improved.

According to a fifth aspect of the present invention, there is provided the prism according to the third aspect, further comprising two optical film bases provided with a wavelength-selective reflective film constituting one dichroic surface,
In these optical film substrates, a wavelength-selective reflection film is provided on a predetermined surface facing in the same direction, and the predetermined surface is arranged flush.

In this configuration, the wavelength-selective reflection film formed on the optical film base is easily arranged flush with the predetermined surface as a reference, and the optical characteristics are improved.

According to a sixth aspect of the present invention, in the prism of the fifth aspect, a relief portion for preventing interference between the optical film substrate and an adjacent optical film substrate is provided at the intersection of the plurality of dichroic surfaces. It is provided.

In this configuration, the wavelength-selective reflecting film is easily and continuously arranged also at the portion where the two dichroic surfaces intersect, thereby improving the optical characteristics.

According to a seventh aspect of the present invention, in the prism according to the sixth aspect, a gap formed between the escape portions is filled with a filler.

With this configuration, even if the end of the optical film substrate is not sufficiently finished, irregular reflection is suppressed by the filler,
The optical characteristics are improved while reducing the manufacturing cost.

The prism according to claim 8 is the prism according to claim 3, wherein the wavelength-selective reflection film constituting one dichroic surface is one surface of one optical film substrate bonded to a plurality of prism elements. It is provided in.

In this configuration, the manufacturing process is simplified and the manufacturing cost is reduced, as compared with the configuration in which the optical film base is bonded to each prism element and aligned.

The prism according to claim 9 is the prism according to any one of claims 1 to 8, wherein the optical film base is
It has a protruding guide portion protruding from the prism element.

In this configuration, the optical film substrate is easily and accurately positioned by bringing the jig into contact with the protruding guide portion, thereby improving the optical characteristics while reducing the manufacturing cost.

According to a tenth aspect of the present invention, there is provided a prism manufacturing method,
An optical film is formed on at least one surface of an optical film substrate, and the optical film substrate is bonded between a plurality of prism elements.

In this configuration, since the optical film is formed not on the prism element but on the optical film substrate bonded to the prism element, when the formation of the optical film fails,
The loss of the optical film base is sufficient, and the manufacturing cost can be reduced as compared with the configuration in which the optical film is formed directly on the prism element.

[0026] The method for manufacturing a prism according to claim 11 is as follows.
The method for manufacturing a prism according to claim 10, wherein the prism element is a right-angle prism, the optical film substrate is a glass plate, and the optical film is formed by vapor-deposition on one surface of each optical film substrate. These optical films constitute two dichroic surfaces orthogonal to each other.

In this configuration, when the deposition of the wavelength-selective reflective film fails, the loss of the glass plate is sufficient, and the manufacturing cost of the prism having two dichroic surfaces can be reduced.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing a prism.
12. The method for manufacturing a prism according to claim 11, wherein a guide member provided with a guide portion abutting on both surfaces of a virtual surface including one dichroic surface is used, and a wavelength-selective reflection film forming one dichroic surface; Two optical film bases provided on a predetermined surface with a protruding guide portion abutting on the guide portion are arranged such that the predetermined surfaces face each other and the predetermined surfaces are flush with each other.

In this configuration, the two optical film substrates are easily and accurately positioned by bringing the guide portion of the guide jig into contact with the protruding guide portion, thereby reducing the manufacturing cost and improving the optical characteristics. Become good.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a prism and a method of manufacturing the prism according to the present invention will be described below with reference to the drawings.

1 and 2, reference numeral 10 denotes a color synthesizing prism as a prism. The color synthesizing prism 10 is also called a cross prism or a cross dichroic prism, and is used for color synthesis of a liquid crystal projector as a projector. And first to fourth four right-angle prisms 11, 12, 13, as prism elements.
14 and first to fourth substrates 21 and 2 as optical film bases.
2, 23 and 24 are adhered to each other.

Each of the right-angle prisms 11, 12, 13, 14
Is made of a transparent glass or resin, etc., and the end face is formed in the shape of a right triangular prism.
It is a bonding surface that can be bonded to each other via 2, 23, and 24.

Each of the substrates 21, 22, 23, 24 is formed of a transparent glass plate or a resin plate having a rectangular flat plate shape.
Dichroic films D1, D2, D3, as wavelength-selective reflective films, which are optical films that have predetermined optical characteristics on one surface, respectively.
D4 is formed by vapor deposition or the like. In addition, each substrate 21, 2
It is desirable that the glass plates constituting 2, 23 and 24 be formed as thin as possible.

The dichroic films D1 and D3 formed on the first and third substrates 21 and 23 have optical characteristics equivalent to each other, and emit red light, that is, visible light having a wavelength longer than a predetermined value. A wavelength-selective reflective film that reflects and transmits color light having a wavelength shorter than the red light is formed by vapor deposition as a dielectric multilayer film. Further, the first and third substrates 21 and 23 are provided with first and third right-angle prisms 11 and
13, the width dimension is substantially equal to the width dimension of the right-angled face, the height dimension is larger than the height dimension of the right-angled face, that is, the dimension between the end faces, and the upper and lower ends are the first and the second. Third
Projections protruding from the upper and lower end faces of right angle prisms 11 and 13
21a and 23a.

The dichroic films D2 and D4 formed on the second and fourth substrates 22 and 24 have optical characteristics equivalent to each other and reflect blue light, that is, a wavelength shorter than a predetermined value. A wavelength-selective reflective film that reflects visible light and transmits color light having a wavelength longer than that of blue light is formed by vapor deposition as a dielectric multilayer film. The first and third substrates 21 and 23 are formed in a rectangular shape having substantially the same width dimension and height dimension as the right-angled surfaces of the first and third right-angle prisms 11 and 13.

The right angle prisms 11, 12, 13, 14
Are arranged with the right-angled surfaces facing each other, and the first
Between the right-angle prism 11 and the second right-angle prism 12
The substrate 21 is connected to the dichroic film D1 by the second right-angle prism 12
And the second substrate 22 is sandwiched between the second right-angle prism 12 and the third right-angle prism 13 by a dichroic film.
D2 is sandwiched between the third right-angle prism 13 and the third substrate 23 and the dichroic film D3 is placed between the third right-angle prism 13 and the fourth right-angle prism 14. And the fourth substrate 24 is sandwiched between the fourth right-angle prism 14 and the first right-angle prism 11 by a dichroic film D4.
In the state of being pinched toward the first right-angle prism 11,
Each right angle prism 11, 12, 13, 14 and each substrate 21, 22, 23, 24
Are bonded together with a transparent adhesive such as an ultraviolet (UV) curable resin to form a substantially rectangular parallelepiped or cubic integrated color synthesis prism 10 as a whole. Each of the right-angle prisms 11, 12, 13, 14 and each of the substrates 21, 22, 23, 24 are dichroic films D1, D3 having optical characteristics equivalent to each other.
Are arranged so as to be located on the same plane, and have dichroic films D2 and D4 having optical characteristics equivalent to each other.
Are arranged on the same plane.

Then, in this state, the first and third dichroic films D 1 and D 3 are provided in each diagonal direction of the color combining prism 10.
Red dichroic surface Dr formed by
And a blue dichroic surface Db formed by the dichroic films D2 and D4.

The color synthesizing prism 10 thus configured is adhered on a support (not shown), and the first right-angle prism 11 is directed to the projection optical system (photographing optical system). It is fixed at a predetermined position on the housing of the device. The liquid crystal projector includes a light source, a dichroic mirror that separates white light into red color light R, green color light G, and blue color light B, and three liquid crystal displays as modulation units that respectively modulate the separated color lights. Panels are provided. The second right-angle prism 12 receives modulated red color light R, the third right-angle prism 13 receives modulated green color light G, and the fourth right-angle prism 14 receives modulated blue color light B. Each of the incident light is reflected or transmitted by each of the dichroic surfaces Dr and Db for each color light, and the RGB color lights are combined into one light flux. The combined light W is emitted from the first right-angle prism 11 and projected by the projection optical system. , An enlarged projection image is projected on a projection surface (screen) via the.

Next, a process of assembling the color synthesizing prism 10 will be described.

Note that dichroic films D1, D2, D3, and D4 are previously formed on predetermined surfaces of the substrates 21, 22, 23, and 24, and those having no desired characteristics are excluded.

First, the manufacturing apparatus used in this assembling process includes a flat base 31 and a pair of left and right guide jigs 32, 32. The flat base 31 is, as shown in FIG. 31a. Each of the guide jigs 32 has a substantially C-shape or the like, as shown in FIGS. 4 and 5, and a pair of upper and lower arms 33, 33, and a connection for connecting the arms 33, 33. Part 34, and guide parts 35, 35 provided so as to protrude from the tip parts of the respective arm parts 33, 33 so as to face each other. One surface of the arm part 33 and the guide part 35 is a flat surface. Guide surfaces 36, 36
It has become.

The assembling process is a process of bonding the members using the flat base 31 to form the units A and B, and bonding the units A and B together using the guide jigs 32. Forming the color synthesizing prism 10.

First, the step of forming the unit A is shown in FIG.
As shown in (a), the first and second right-angle prisms 11,
12 is bonded to the first and second substrates 21 and 22. The first right-angle prism 11 and the second right-angle prism 12 are arranged so that their right-angled surfaces face each other.
The first substrate 21 is disposed between the opposed right-angled surfaces with the dichroic film D1 facing the second right-angle prism 12. Further, the second substrate 22 is placed on the flat portion 31a with the dichroic film D2. Toward, it is arranged between the second right-angle prism 12 and the plane portion 31a of the plane table 31.

Thus, between the first right-angle prism 11 and the first substrate 21, between the first substrate 21 and the second right-angle prism 12, and between the second right-angle prism 12 and the second An ultraviolet (UV) curable resin is applied between the substrate 22 and the substrate 22. Then, in this state, the right-angled surface facing the flat portion 31a of the first right-angled prism 11, the end surface of the first substrate 21, and the second substrate 22
Are pressed against the flat portion 31a, that is, the flat portion 31a is positioned as a guide, and the first right-angle prism 11 and the first right
The substrate 21, the second right-angle prism 12, and the second substrate 22 are brought into close contact with each other to cure the ultraviolet curable resin to form the unit A.

Similarly, the step of forming the unit B includes, as shown in FIG. 3B, the third and fourth right-angle prisms 1.
The third and fourth substrates 23 and 24 are bonded together with the third and fourth substrates 23 and 24. The third right-angle prism 13 and the fourth right-angle prism 14 are arranged such that their right-angled surfaces face each other.
The third substrate 23 is disposed between the opposed right-angled faces with the dichroic film D3 facing the fourth right-angle prism 14. Further, the fourth substrate 24 is mounted on the flat portion 31a with the dichroic film D4. The fourth prism 14 is disposed between the fourth right-angle prism 14 and the flat portion 31a of the flat base 31.

Thus, between the third right-angle prism 13 and the third substrate 23, between the third substrate 23 and the fourth right-angle prism 14, and between the fourth right-angle prism 14 and the fourth An ultraviolet (UV) curable resin is applied between the substrate 24 and the substrate 24. Then, in this state, the right-angled surface facing the flat portion 31a of the third right-angled prism 13, the end surface of the third substrate 23, and the fourth substrate 24
Are pressed against the flat portion 31a, that is, the flat portion 31a is positioned as a guide, and the third right-angle prism 13 and the third
The substrate 23, the fourth right-angle prism 14, and the fourth substrate 24 are brought into close contact with each other to cure the ultraviolet curable resin, thereby forming the unit B.

When these units A are formed, the upper and lower ends of the first substrate 21 project from the upper and lower end surfaces of the first and second right-angle prisms 11 and 12 to form a projecting guide portion 21a. As described above, when the unit B is formed, the third
The first substrate 21 and the third substrate 23 are formed such that upper and lower ends project from upper and lower end surfaces of the third and fourth right-angle prisms 13 and 14 to form projecting guides 23a. Adjust the sticking position in the vertical direction.

Next, a process of bonding the units A and B together will be described with reference to FIG.

First, a pair of guide jigs 32, 32 are overlapped so that the guide surfaces 36, 36 face each other.
36, 36 are almost flush. Then, one guide jig 32
The projecting guide portion 21a of the first substrate 21 of the unit A is brought into contact with the guide surface portion 36 of the unit A in a planar manner to serve as a guide.
The projecting guide portion 23a of the third substrate 23 of the unit B is brought into planar contact with the guide surface portion 36 of the other guide jig 32 from the opposite side to form a guide.

The guide surface 36 and the projecting guide 21
a, 23a, while keeping the state in which they are brought into close contact with each other, the right-angled surface of the dichroic film D2 of the second substrate 22 and the third right-angle prism 13 and the fourth The dichroic film D4 of the substrate 24 and the right-angled surface of the first right-angled prism 11 are brought into close contact with each other, and the ultraviolet curable resin is cured.

Then, if necessary, the upper and lower projecting guides
The color combining prism 10 is completed by deleting 21a and 23a.

According to the present embodiment, the first dichroic film D1 and the third dichroic film D3, and
Second dichroic film D2 and fourth dichroic film D4
Are bonded to the right-angle prisms 11, 12, 13, and 14 in the direction in which the dichroic films face each other. Therefore,
The step between the first dichroic film D1 and the third dichroic film D3 whose surface on which the wavelength-selective reflective film is formed is positioned using the guide jigs 32, 32 is only the thickness of the wavelength-selective reflective film. The blue dichroic surface Db, which is almost even, can be formed, the optical characteristics can be improved, the deterioration of the projected image of the light reflected by the blue dichroic surface Db can be suppressed, and the image quality of the liquid crystal projector device can be reduced. Can be improved.
Also, the steps of the second dichroic film D2 and the fourth dichroic film D4 can be reduced to only the thickness of the wavelength-selective reflection film and the thickness of the adhesive layer, and the red dichroic surface is almost even. Dr can be formed, the optical characteristics can be improved, the deterioration of the projected image of the light reflected by the red dichroic surface Dr can be suppressed, and the image quality of the liquid crystal projector can be improved. Further, the units A and B can be formed by calculating the thickness of the wavelength-selective reflection film and the thickness of the adhesive layer in advance. That is, it is possible to realize a simple means for bonding the right-angle prisms in a state where the thicknesses of the wavelength-selective reflection film and the adhesive layer are shifted in anticipation of the thickness of the wavelength-selective reflection film and the adhesive layer, thereby making the same kind of reflection surface even.

Further, the first dichroic film D1 and the third
Dichroic film D3 and the second dichroic film
D2 and the fourth dichroic film D4 are respectively right-angle prisms 11, 12, 13, 14 in the direction in which the dichroic films face each other.
Therefore, the dichroic surfaces Db and Dr can be continuously formed even at the intersection of the blue dichroic surface Db and the red dichroic surface Dr.

In this way, it is possible to easily realize a uniform reflection surface, which is an optical film of the same kind, to improve optical characteristics, and to improve the quality of an image of a liquid crystal projector.

The dichroic films D1, D2, D3, D4
Are formed on the substrates 21, 22, 23, and 24, which are glass plates, respectively.
Only the glass plate needs to be discarded, and each right-angle prism 11,1
Compared with a configuration in which a dichroic film is formed directly on 2, 13, and 14, it is possible to suppress a decrease in cost when the formation of a wavelength-selective reflective film by vapor deposition fails.

Projection guides 21a and 23a are projected from the units A and B constituting the color combining prism 10, and the projections 21a and 23a are brought into contact with the guide 35 projected from the guide jig 32. Since the guide surface portion 36 is provided so as to be in contact, the guide jig 32 does not interfere with the main body portion related to the color synthesis of the color synthesis prism 10, and the positioning operation can be facilitated.
Optical characteristics can be improved.

It should be noted that the dielectric multilayer film of a plurality of substrates constituting the same dichroic surface has the same wavelength selection characteristic, that is, whether it is incident from the front side of the film or from the rear side, that is, from the glass side of the substrate. Since it has reflection and transmission characteristics, it is possible to reduce the manufacturing cost by using a substrate in which films are laminated on glass in the same order. Further, with respect to a pair of substrates arranged opposite to each other, a substrate in which films are stacked in the opposite order on the surface of glass may be arranged opposite to adjust the reflection / transmission characteristics. Further, as long as the wavelength selection characteristics are the same, a substrate provided with an optical film having a different laminated structure or the like can be used.

In the above-described embodiment, the unit A and the unit B
However, without forming such a unit, the members are simultaneously combined and bonded to reduce or eliminate the influence of the thickness of the adhesive layer, and the step on the dichroic surface is reduced only by the thickness of the wavelength-selective reflection film. It can also be.

Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

For example, in this configuration, as in the second embodiment shown in FIG. 6, projecting guide portions 21a and 23a are formed above and below the first and third substrates 21 and 23, and the second and third substrates 21 and 23 are formed. Projection guides 22a and 24a are formed above and below the fourth substrates 22 and 24, respectively. Further, the flat base 31 is not used, and a pair of second guide jigs 42, 42 are used in addition to the pair of guide jigs (hereinafter, first guide jigs) 32, 32. This second guide jig 42, 42
Has the same shape as the first guide jigs 32, 32, and a large height dimension, that is, the connecting portion 34 and the guide portions 35, 35 are formed longer than the first guide jigs 32, 32. I have. Therefore, in a state where each member is coated with an ultraviolet curing resin in advance,
Combined with the same arrangement as the color combining prism 10 shown in FIG.
The guide surfaces 36, 36 of the first guide jigs 32, 32 are positioned in contact with the upper and lower projecting guides 21a, 23a of the first and third substrates 21, 23, and at the same time, the second guide jig 42 is set. , 42 are positioned by contacting the upper and lower projecting guides 21a, 23a of the second and fourth substrates 22, 24.

In each of the above embodiments, each of the substrates 21, 22, 23, on which the dichroic films D1, D2, D3, D4 are formed, is formed.
The dichroic films D1, D3, D2, and D4 form the same dichroic surfaces Dr and Db, each having a shape attached to one of the right-angled prisms 11, 12, 13, and 14.
Are arranged so as to face each other, but the substrates constituting the same dichroic surface are integrally formed, that is, the dichroic film constituting the same dichroic surface is integrally formed, and the step of the dichroic surface is eliminated and the surface is formed. The manufacturing process can be simplified by eliminating the need to use a flat base for alignment.

When one or two dichroic surfaces are formed by a plurality of substrates, the dichroic films are aligned in the same direction, and each substrate is attached to each right-angle prism. The step can be reduced.

For example, as in the color combining prism 50 of the third embodiment shown in FIGS.
In addition to 11, 12, 13, and 14, fifth and sixth substrates 51 and 52 formed by vapor-depositing dichroic films D5 and D6 constituting a red dichroic surface Dr on surfaces facing the same direction, and a blue dichroic surface Db And a seventh substrate 53 formed by vapor-depositing a dichroic film D7 over the entire surface. And
Each of the fifth and sixth substrates 51 and 52 has a width dimension substantially equal to the right-angle plane of each of the right-angle prisms 11, 12, 13, and 14, and a height larger than the right-angle plane. ,13,
Projection guide portions 51a and 52a for positioning are provided on the upper and lower sides of the projection 14. Further, the seventh substrate 53 has a size corresponding to approximately two right-angled surfaces.

In the bonding step of the third embodiment, first, as shown in FIG.
On the surface opposite to the surface on which 53 dichroic films D7 were formed,
The first and second right-angle prisms 11 and 12 are arranged with their right-angled surfaces facing the seventh substrate 53 and the right-angled surfaces facing each other, and a dichroic film D5 is placed between these right-angled surfaces. The fifth substrate 51 is arranged toward the right-angle prism 12. Then, between the first right-angle prism 11 and the fifth substrate 51, between the fifth substrate 51 and the second right-angle prism 12, and between the first and second right-angle prisms 11, 12 and The right-angled surfaces of the first and second right-angle prisms 11 and 12 and the end surface of the fifth substrate 51 are attached to the seventh substrate 53 with the ultraviolet-curing resin applied thereto.
The first and second right-angle prisms 11 and 12 and the fifth and seventh prisms 53 are pressed against the first substrate 53 and the seventh substrate 53 is used as a guide.
The substrates 51 and 53 are brought into close contact with each other, and the ultraviolet curable resin is cured to form a unit C.

Next, as shown in FIG. 9B, a third right-angle prism 13 and a fourth right-angle prism 14 are placed between right-angled surfaces, and a sixth dichroic film D6 is placed on the third right-angled prism. The sixth substrate 52 is sandwiched between the prism 13 and the flat portion 31 of the flat base 31.
The unit D is formed by pressing against a, that is, positioning the flat portion 31a as a guide, and then bringing these members into close contact with each other via an ultraviolet curable resin applied in advance and curing the ultraviolet curable resin.

Next, as shown in FIG. 10, a guide jig 55 having a rectangular frame shape or the like is used, and one surface of the guide jig 55 is provided on the same side of the protruding guide portions 51a, 52a, that is, the dichroic film D5. The unit C and the unit D, namely, the seventh substrate
The surface on which the 53 dichroic film D7 is formed, the third right-angle prism 13 and the fourth right-angle prism 14 are brought into close contact with each other via an ultraviolet-curable resin applied in advance, and the ultraviolet-curable resin is cured to form a color synthesis prism 50. I do.

According to the third embodiment,
The blue dichroic surface Db composed of one dichroic film D7 can be easily formed to be flush, and even if it is attached to the red dichroic surface Dr composed of two dichroic films D5 and D6, it is guided on the plane of the guide jig 55. Thus, flushing can be easily achieved.

In the configuration in which the dichroic films are oriented in the same direction of the substrate as in the third embodiment, the red dichroic surface Dr is formed at the center where the blue dichroic surface Db and the red dichroic surface Dr intersect. However, the dichroic parts are cut off at the center part, that is, at the intersection of the glass plates, by forming an escape part by processing the end of each substrate into an acute angle, etc. The surfaces Db and Dr can be formed almost continuously, the optical characteristics can be improved, and the image quality of the liquid crystal projector can be improved. When a gap is formed between each right-angle prism and the end of each substrate by forming these escape portions, a filler such as a transparent resin such as an ultraviolet curable resin is filled in the gap. By filling, even when the mirror finish of the glass edge is insufficient, irregular reflection can be prevented, the optical characteristics can be improved, and the quality of the image of the liquid crystal projector can be improved.

For example, the color combining prism 60 according to the fourth embodiment shown in FIGS.
2, 13, 14 are arranged with their right-angled surfaces facing each other, and between the first right-angled prism 11 and the second right-angled prism 12, the eleventh substrate 61 is attached with the dichroic film D11 to the second right-angled prism. The twelfth substrate 62 is sandwiched between the second right-angle prism 12 and the third right-angle prism 13 with the dichroic film D12 facing the third right-angle prism 13 between the second right-angle prism 12 and the third right-angle prism 13. The thirteenth substrate 63 is sandwiched between the third right-angle prism 13 and the fourth right-angle prism 14 with the dichroic film D13 facing the third right-angle prism 13. The fourteenth substrate 64 is sandwiched between the first right-angle prism 11 and the right-angle prism 11 with the dichroic film D14 facing the first right-angle prism 11 side.
The substrates 3, 61, 62, 63, and 64 are bonded to each other with a transparent adhesive such as an ultraviolet curing resin to form a substantially rectangular parallelepiped or cubic integrated color synthesis prism 60 as a whole.

That is, in this configuration, the eleventh substrate 61
And the thirteenth substrate 63 are formed on the same side to form a red dichroic surface Dr, and the dichroic films D12 and D14 of the twelfth substrate 62 and the fourteenth substrate 64 are formed. The blue dichroic surface Db is formed on the same surface.

Further, in this configuration, each of the substrates 61, 62, 6
An end surface on the center side of 3, 64 is formed into an acute angle taper surface by polishing or the like, that is, dichroic films D11, D1
2, D13 and D14 are shaved off the opposite side to form a relief.

Therefore, as shown in FIGS. 13 and 14,
When the color combining prism 60 is assembled in the same process as in the first embodiment, that is, the first and second right-angle prisms 1 are assembled.
The unit E is formed by bonding the first and twelfth substrates and the eleventh, twelfth and fourteenth substrates 61, 62 and 64 to each other with reference to the flat portion 31a of the flat base 31 to form a unit E. The prisms 13 and 14 and the thirteenth substrate 63 are connected to the flat portion 31a of the flat base 31.
The unit F is adhered to each other on the basis of the above, and a guide jig 55 such as a square frame is brought into contact with the protruding guide portions 61a, 63a protruding above and below the eleventh and thirteenth substrates 61, 63. And the eleventh and thirteenth dichroic films D11, D13
When the unit E and the unit F are adhered to each other while keeping the surfaces flush, the tip of the fourteenth substrate 64 is inserted into the clearance formed in the eleventh and thirteenth substrates 61 and 63, and the central part Thus, the color synthesizing prism 60 can be formed in a state where the dichroic surfaces Db and Dr are continuous with each other.

Here, when the tapered surfaces at the ends of the substrates 61, 62, 63, 64 are brought into close contact with each other, the angles of the end surfaces are adjusted with high precision in order to make the dichroic surfaces Db, Dr continuous. Need to be processed. Therefore, these substrates 6
At the ends of 1, 62, 63, 64, dichroic film D11
, D12, D13, and D14 are slightly larger than those formed by forming a relief by polishing, etc.
The polishing cost and the like can be reduced and the production cost can be reduced without the need to increase the processing accuracy more than necessary. Furthermore, each substrate 61,
Filling the gap 66 formed at the part where the parts 62, 63, and 64 abut with each other with a filler such as an ultraviolet curable resin can prevent irregular reflection of light on the end face even when the end face is not mirror-finished, The optical characteristics can be improved while the manufacturing cost is reduced, and the image quality of the liquid crystal projector can be improved.

In each of the above embodiments, the prism is described as a color combining prism. However, the present invention can be applied to, for example, a color separating prism that separates white light into a plurality of color lights.

In each of the above embodiments, the adhesive for bonding the members and the filler filled in the gap are not limited to the ultraviolet curable resin, and various resins, adhesives, and the like may be used. it can.

[0076]

According to the first aspect of the present invention, the optical film is formed not on the prism element but on the optical film substrate bonded to the prism element. And the manufacturing cost can be reduced as compared with the configuration in which the optical film is formed directly on the prism element.

According to the prism of the second aspect, in addition to the effect of the first aspect, when the deposition of the optical film fails,
The glass plate can be lost, and the manufacturing cost can be reduced.

According to the prism of the third aspect, in addition to the effects of the first or second aspect, a prism having two dichroic surfaces orthogonal to each other can be easily manufactured, and the manufacturing cost can be reduced.

According to the prism of the fourth aspect, in addition to the effect of the third aspect, by using a predetermined surface as a reference,
The wavelength-selective reflection films formed on the two optical film substrates can be easily arranged on the same plane, and the optical characteristics can be improved. In addition, the wavelength-selective reflecting film can be easily and continuously arranged also at a portion where the two dichroic surfaces intersect, and the optical characteristics can be improved.

According to the prism of the fifth aspect, in addition to the effect of the third aspect, by using a predetermined surface as a reference,
The wavelength-selective reflective film formed on the optical film substrate can be easily arranged on the same plane, and the optical characteristics can be improved.

According to the prism of the sixth aspect, in addition to the effect of the fifth aspect, at the intersection where a plurality of dichroic surfaces intersect, interference between the optical film substrate and the adjacent optical film substrate is prevented. Since the escape portion is provided, the wavelength-selective reflection film can be easily and continuously arranged also at a portion where the two dichroic surfaces intersect, and the optical characteristics can be improved.

According to the prism of the seventh aspect, in addition to the effect of the sixth aspect, the gap formed between the clearances is filled with the filler, so that the edge of the optical film substrate is not sufficiently finished. However, irregular reflection can be suppressed by the filler, and the optical characteristics can be improved while reducing the manufacturing cost.

According to the prism of the eighth aspect, in addition to the effect of the third aspect, one optical film in which a wavelength-selective reflection film constituting one dichroic surface is bonded to a plurality of prism elements By providing the optical film substrate on one surface of the substrate, the manufacturing process can be simplified and the manufacturing cost can be reduced as compared with a configuration in which the optical film substrate is bonded to each prism element and aligned.

According to the ninth aspect of the invention, in addition to the effects of the first to eighth aspects, since the optical film base is provided with the projecting guide portion projecting from the prism element, the jig is applied to the projecting guide portion. By making contact, the optical film substrate can be easily and accurately positioned, and the optical characteristics can be improved while reducing the manufacturing cost.

According to the tenth aspect of the present invention, the optical film is formed not on the prism element but on the optical film substrate bonded to the prism element. The production cost can be reduced as compared with the configuration in which the optical film is formed directly on the prism element, because the loss of the film base is sufficient.

According to the method for manufacturing a prism according to the eleventh aspect, in addition to the effect according to the tenth aspect, when the deposition of the wavelength-selective reflection film fails, the loss of the glass plate is sufficient and the two dichroic surfaces are sufficient. The manufacturing cost of the prism having the above can be reduced.

According to the manufacturing method of the prism of the twelfth aspect, in addition to the effect of the eleventh aspect, the guide of the guide jig is brought into contact with the projecting guide of the two optical film substrates. The optical film substrates are easily and accurately positioned,
The optical characteristics are improved while reducing the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a prism of the present invention.

FIG. 2 is a plan view of the same prism.

FIG. 3 is an explanatory view showing a manufacturing process of the prism.
(A) is a plan view (b) is a plan view

FIG. 4 is an explanatory view showing a manufacturing process of the prism. (A) is a plan view (b) is a side view

FIG. 5 is a perspective view of an apparatus used in a manufacturing process of the prism.

FIG. 6 is an explanatory diagram showing a manufacturing process of the second embodiment of the prism of the present invention.

FIG. 7 is a perspective view showing a third embodiment of the prism of the present invention.

FIG. 8 is a plan view of the same prism.

FIG. 9 is an explanatory view showing a manufacturing process of the prism. (A) is a plan view (b) is a plan view

FIG. 10 is an explanatory view showing a manufacturing process of the prism.

FIG. 11 is a perspective view showing a fourth embodiment of the prism of the present invention.

FIG. 12 is a plan view of the prism.

FIG. 13 is an explanatory view showing a manufacturing process of the prism. (A) is a plan view (b) is a plan view

FIG. 14 is an explanatory view showing a manufacturing process of the prism.

[Explanation of symbols]

 10 Color synthesis prism as prism 11, 12, 13, 14 Right angle prism as prism element 21, 22, 23, 24 Substrate as optical film substrate 21a, 23a Projection guide 32 Guide jig 35 Guide 66 Gap D1 , D2, D3, D4 Dichroic film as optical film Db Blue dichroic surface as dichroic surface Dr Red dichroic surface as dichroic surface

Claims (12)

[Claims] 1. An optical film substrate comprising: a plurality of prism elements having a bonding surface; an optical film substrate bonded between the bonding surfaces; and an optical film formed on at least one surface of the optical film substrate. Prism. 2. The prism according to claim 1, wherein the optical film substrate is a glass plate, and the optical film is formed by vapor deposition on one surface of each optical film substrate. 3. The prism element according to claim 1, wherein the prism element is a right-angle prism, the optical film is a wavelength-selective reflection film, and these optical films constitute two dichroic surfaces orthogonal to each other. Prism. 4. An optical film base comprising two optical film substrates provided with a wavelength-selective reflective film constituting one dichroic surface, wherein the optical film substrates are provided with a wavelength-selective reflective film on predetermined surfaces facing each other. 4. The prism according to claim 3, wherein said predetermined surface is arranged flush. 5. An optical film base provided with a wavelength-selective reflective film constituting one dichroic surface, wherein the optical-film bases are provided with a wavelength-selective reflective film on a predetermined surface facing in the same direction. 4. The prism according to claim 3, wherein said predetermined surface is arranged flush. 6. The prism according to claim 5, wherein a relief portion for preventing interference with an adjacent optical film base is provided in the optical film base at an intersection where the plurality of dichroic surfaces intersect. 7. The prism according to claim 6, wherein a gap formed between the escape portions is filled with a filler. 8. The optical film substrate according to claim 3, wherein the wavelength-selective reflection film constituting one dichroic surface is provided on one surface of one optical film substrate bonded to the plurality of prism elements. prism. 9. The prism according to claim 1, wherein the optical film base includes a projecting guide portion projecting from the prism element. 10. A method for manufacturing a prism, comprising: forming an optical film on at least one surface of an optical film substrate; and bonding the optical film substrate between a plurality of prism elements. 11. The prism element is a right-angle prism, the optical film substrate is a glass plate, and the optical film is a wavelength-selective reflective film formed by vapor deposition on one surface of each optical film substrate. 11. The method according to claim 10, wherein the film forms two dichroic surfaces orthogonal to each other. 12. A wavelength-selective reflection film constituting one dichroic surface and a projection abutting on the guide portion using a guide jig provided with a guide portion abutting on both surfaces of a virtual surface including one dichroic surface. 12. The method of manufacturing a prism according to claim 11, wherein the two optical film substrates each having a guide portion provided on a predetermined surface are arranged such that the predetermined surfaces face each other and the predetermined surfaces are flush with each other.