JPH10186195A - Method and device for connecting optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a high-precision composite optical element by matching a border position by an optical surface formed on one optical element with a reference plane position corresponding to the plane position of the other optical element. SOLUTION: Two end points on both the sides of a border position W as a part appearing on the surface of an optical surface (either light separating surface formed of a polarized light separating film or optical surface formed of a mere reflecting surface formed of a reflecting film) formed at a nearly center part of a polarization beam splitter(PBS) are decided as positioning adjustment points P and Q, which are adjusted by moving a positioning frame 11 in an (x), a (y), and a (θ) direction so that they meet previously set reference points 14 and 15. Consequently, positioning can be done on the basis of the optical structure itself of the PBS 1, so the influence of optical characteristics due to a shift of a connection surface resulting from variance in the shape of the PBS 1 can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for joining optical elements, and more particularly to a method for joining two optical elements having at least one of a plurality of optical surfaces for determining optical characteristics. About technology.

[0002]

2. Description of the Related Art Optical element bonding techniques for bonding two or more optical elements to each other have been conventionally implemented by various methods. For example, optical lenses and prisms are often bonded to each other with an adhesive, and a variety of optical characteristics that cannot be realized with a single optical element or are difficult to be realized with a single optical element can be obtained by such a composite lens or prism. Can be.

As an optical element, various integrators for correcting divergent light from a light source to parallel light are used. This integrator is used to obtain desired characteristics in an optical system by converting light into parallel light, and to reduce optical loss in the optical system.

For example, in a liquid crystal projector, an integrator is formed on the light exit side of a light source to convert light into parallel light and increase the amount of light transmitted through a liquid crystal shutter at a later stage and finally projected to the outside. For this purpose, the polarization directions of light are aligned by a polarization beam splitter (hereinafter simply referred to as “PBS”), thereby improving light use efficiency.

In this case, an optical lens (for example, a lens array having a large number of microlenses in a light transmitting surface) constituting an integrator and the above-mentioned PBS are adhered to each other to obtain desired optical characteristics and at the same time obtain optical characteristics. In some cases, the size of the system is reduced and the optical loss is further reduced.

[0006]

However, when the optical elements are joined to each other as described above, the positional relationship between the optical structures that determine the individual optical characteristics of the optical elements must be exactly matched to each other. If they are not bonded together, there is a problem that desired optical characteristics as a composite element cannot be obtained and optical loss increases.

Usually, the outer peripheral portions of the two optical elements are precisely machined, and these outer peripheral portions are fixed with a jig to perform positioning between the optical elements. However, it is difficult to accurately process the outer peripheral portion of the optical element in accordance with the optical structure, and since the processing must be performed while measuring the optical characteristics at the time of processing, there is a problem that the manufacturing cost increases. .

Further, some optical elements may include a certain error in the optical structure itself, for example, because the optical structure is formed by mechanical processing. For example, a light separating surface for separating light according to the polarization direction. However, there is a problem that the optical structure and the outer shape vary due to the mechanical accuracy of the polarizing beam splitter and the like, and it is difficult to obtain the outer shape accuracy for the optical structure itself.

Accordingly, the present invention has been made to solve the above-mentioned problems. Particularly, in a case where an optical element having a plurality of optical separation surfaces or other optical surfaces for separating light according to a polarization direction and another optical element are joined, An object of the present invention is to form a high-precision composite optical element by performing positioning between optical elements in accordance with a structure that reflects the optical characteristics of the optical element.

[0010]

Means taken by the present invention to solve the above-mentioned problems are a first optical element and a second optical element, at least one of which has a plurality of optical surfaces for determining optical characteristics. In an optical element bonding method for bonding
The first optical element is fixed in a predetermined plane, the second optical element is superimposed on the first optical element, and a boundary position formed by the optical surface is made visible so that the boundary position is Adjusting and positioning the plane position of the second optical element so as to match a reference plane position corresponding to the plane position of the other optical element, and thereafter joining the first optical element and the second optical element. It is characterized by.

According to this means, since the boundary position by the optical surface formed on one optical element is positioned so as to coincide with the reference plane position corresponding to the plane position of the other optical element, the related art is used. Optical positioning can be performed with higher accuracy than that, and the optical characteristics of the composite optical element can be improved. Further, unlike the related art, since it is not necessary to perform the alignment depending on the outer shape of the optical element, the accuracy of the outer shape of the optical element itself is not so required, and the processing cost and processing time of the optical element can be reduced.

The optical surface is a surface shape constituting at least a part of the optical structure, and the boundary position of the optical surface is
It is a position indicating the boundary of various optical structures formed by the optical surface, and formed by a light separating surface, a light reflecting surface, a light refracting surface, etc., whose transmission characteristics change according to the polarization direction of light.
For example, it includes a singular point or a singular line of the optical structure in the optical element, such as a portion where the curvature of the surface changes. Here, when there is a boundary line that appears on the surface of the optical element on the viewing side, it is preferable to set the boundary line as the boundary position of the optical surface from the viewpoint of visibility.

Here, it is preferable that the positioning is performed while visually recognizing the boundary position from the side of the first optical element or the second optical element having the optical surface.

According to this means, the position can be adjusted even when viewed from the side of the other optical element. However, by performing the position adjustment while viewing from the side of the optical element having the optical surface, the boundary position can be further improved. It can be clearly grasped, and positioning can be performed with high accuracy.

A light separating surface having a light transmission characteristic depending on a polarization direction is formed in the optical element having the optical surface, and the first optical element and the second optical element are irradiated with polarized light. Preferably, the boundary position is easily recognized by using the transmitted light or the reflected light.

According to this means, by irradiating the polarized light, the light amount ratio of the two light beams separated on the light separating surface changes according to the polarization direction of the irradiated polarized light. Can be more easily visually recognized, so that positioning can be performed with higher accuracy.

Further, a light-curable adhesive is interposed between the first optical element and the second optical element, and after the positioning is completed, light is applied to the first optical element and the second optical element. It is preferable to bond the element.

According to this means, since the joining can be performed only by irradiating the light after the positioning is completed, the joining process and the joining equipment are simplified.

Next, as an optical element bonding apparatus for bonding a first optical element and a second optical element, at least one of which has a plurality of optical surfaces for determining optical characteristics, the first optical element is A fixing member for fixing in a predetermined plane, positioning adjusting means for positioning and adjusting the second optical element in a state of being superimposed on the first optical element, the first optical element and the second optical element; Image acquisition means for making the boundary position formed by the optical surface visible by light received from the optical element, and a reference plane position corresponding to the plane position of the other optical element to match the boundary position, A reference position display unit for displaying the image in a state comparable to the image obtained by the image acquisition unit.

According to this means, the reference plane position displayed by the reference position display means can be compared with the boundary position in the plane image obtained by the image obtaining means, so that the optical position can be easily and accurately determined. The element can be positioned.

Here, a light separating surface having a light transmission characteristic depending on a polarization direction is formed in the optical element having the optical surface, and the light separating surface is provided with respect to the first optical element and the second optical element. It is preferable to provide a polarized light irradiating means for irradiating polarized light for making the boundary position easily visible.

Further, a pressing means for pressing the first optical element and the second optical element to each other, and a photo-curing member interposed between the first optical element and the second optical element. Preferably, a light irradiation means for curing the adhesive is provided.

According to this means, after the positioning is completed, the light-curing adhesive is cured by the light irradiating means while the first optical element and the second optical element are pressed against each other by the pressing means. Joining can be performed.

[0024]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings.

(First Embodiment) FIGS. 1 and 2A are a plan view and a longitudinal sectional view showing a method for bonding an optical element according to the present invention. The present embodiment is a flat rectangular PBS.
1 shows a method of joining a (polarization beam splitter) 1 to a planar rectangular lens array 2.

As shown in FIG. 2B, the PBS 1 is formed by mutually bonding light-transmitting plates A and B made of optical glass or resin. On the front and back of the translucent plate A, a polarization separation film 16 and a reflection film 1 each having polarization characteristics are provided.
7 are coated. Translucent plate A and translucent plate B
Are alternately bonded by a transparent adhesive (not shown) and cut by a plane indicated by lines T1 and T2 shown in FIG. As a result, as shown in FIG.
BS1 has a plate-like shape in which prismatic portions 1a formed of a part of the light-transmitting plate A and prismatic portions 1b formed of a part of the light-transmitting plate B are alternately bonded. A boundary surface between the prism portions 1a and 1b is 45 degrees with respect to a plane (that is, the front surface or the back surface of the PBS 1) indicated by the lines T1 and T2, respectively.
The optical surface is inclined at an angle of degrees and serves as an optical surface on which the polarization separation film 16 or the reflection film 17 exists. As the optical surface, the one formed inside the optical element as described above naturally includes the individual optical curved surface formed on the surface, which constitutes a micro lens of a lens array described later.

The polarization splitting film 16 is, like a coating film used as a normal polarizing beam splitter,
It has a property of transmitting a polarization component having a predetermined polarization direction as it is, and reflecting a polarization component having a polarization direction orthogonal to the polarization direction. For this reason, as shown in FIG. 2B, when light enters the PBS 1 from below in the figure, the light that has entered the prism 1a strikes the polarization separation film 16, and the polarization component having the predetermined polarization direction S remains unchanged. The polarized light component transmitted and having the polarization direction P opposite to the polarization direction S is reflected. After being reflected, the polarized light component having the polarization direction P travels inside the prism portion 1a, is again reflected by the adjacent reflective coating 17, is emitted from the prism portion 1a, and is later adhered. By passing through 1c, the polarization direction is rotated by 90 degrees as a result and emitted as a polarization component in the polarization direction S. Therefore, when light not having a specific polarization direction enters the PBS1, only polarized light having a specific polarization direction (the polarization direction S in the above description) is emitted from the PBS1 with higher energy than a normal polarizing plate. Will be done.

The lens array 2 is a flat element formed of an optical resin, and has a lower surface shown in FIG.
By arranging a plurality of optical curved surfaces formed so as to have specific optical characteristics, a microlens is arranged vertically and horizontally. The upper surface of the lens array 2 is a highly accurate flat surface.

In this embodiment, the lens array 2
As shown in FIG. 1, a flat L-shaped fixed frame 21 and a flat L-shaped pressing cylinder 22 are clamped at the tip. The PBS 1 described above is superposed and adhered on the upper surface of the lens array 2 positioned by the fixing frame 21 and the pressing cylinder 22 in this manner. PBS
A transparent adhesive made of a photocurable resin is applied to the lower surface of 1 to form an adhesive layer 23 shown in FIG. After the PBS 1 is placed on the upper surface of the lens array 2, the positioning frame 1
1 and the holding arm 12 to be fixed. Between the fixed frame 21 and the positioning frame 11,
A position adjusting mechanism in the x, y, and θ directions for adjusting the relative positional relationship between the PBS 1 and the lens array 2 is formed.
It can be adjusted with high accuracy.

Generally, the optical structure of the lens array 2 is
It can be formed with relatively high precision. For example, in the lens array 2, since each microlens and the outer peripheral portion are usually integrally formed by an injection molding method, the outer peripheral portion is fixed to the fixed frame 2.
Fixing at 1 allows accurate positioning.

On the other hand, the PBS 1 needs to be cut, glued, cut and the like of each translucent plate.
The combination of these processing errors at the time of processing causes an error with respect to the design value in the formation position and the formation cycle of the optical surface, so that the optical structure itself varies and the errors of the optical structure are integrated. As a result, the positional relationship between the optical structure and the outer peripheral portion varies greatly for each product.

Therefore, even if both the PBS 1 and the lens array 2 are positioned by a jig or the like at their outer peripheral portions as in the prior art, the optical structures of the two cannot be matched. However, there is a problem that the performance cannot be obtained. For this reason, in the present embodiment, as shown in FIGS. 1 and 2, an optical surface (a light separating surface formed of the polarization separating film 16, also formed of the reflective film 17) is formed substantially at the center of the PBS 1. The two end points on both sides of the boundary position W, which is a portion appearing on the surface of the optical surface formed by a simple reflecting surface, may be used as the positioning adjustment points P,
Q, and the positioning frame 11 is set to x so that the positioning adjustment points P and Q are aligned with predetermined reference positions 14 and 15 (indicated by crosses indicated by alternate long and short dash lines in FIGS. 1 and 2). , Y, θ directions.

By doing so, the positioning can be performed based on the optical structure itself of the PBS1, so that the influence of the optical characteristics due to the displacement of the bonding surface due to the variation in the shape of the PBS1 can be minimized. Can be. Here, the position of the positioning adjustment point is set in accordance with the optical structure of the PBS 1 and is set as the boundary position W of the optical surface so as to be clearly visible. It is most preferable to select the center boundary position among the boundary positions W of the plurality of optical surfaces as the positioning adjustment point as described above, since the amount of displacement of the optical structure can be reduced in all directions.

After the positioning of the PBS 1 is adjusted as described above, light (for example, ultraviolet) is applied from below in FIG.
Is irradiated to cure the adhesive layer 23, and the PBS 1 and the lens array 2 are completely bonded. In this curing step,
It is preferable that the PBS 1 and the lens array 2 are pressed against each other by a press mechanism (not shown) in order to improve the bonding accuracy.

The positioning adjustment points P and Q are set to the reference positions 14,1.
Various methods are conceivable for adjusting to 5. In this embodiment,
Light is irradiated from the lens array 2 side, and positioning adjustment is performed while visually recognizing the PBS 1 side with a microscope or the like. The reference positions 14 and 15 are preferably previously incorporated as grids in the field of view of the microscope in accordance with the position of the fixed frame 21 for fixing the lens array 2. The operator adjusts the x, y, and θ axes of the positioning frame 11 with a micrometer or the like so that the positioning adjustment points P and Q appearing in the field of view are aligned with the grid.

When the fixed frame 21 has a movable structure, it is preferable that the reference positions 14 and 15 be configured so as to interlock with the fixed frame 21. For example, a camera is arranged above the PBS1, an image obtained by the camera is projected on a display device, and a position detection sensor for detecting the position of the fixed frame 21 is provided. By displaying the pointers on the screen of the display device, the reference positions 14 and 15 can always be associated with the planar position of the fixed frame 21.

As the reference positions 14 and 15, it is necessary to set at least two points so that the x, y, and θ directions of the PBS 1 can be adjusted. The reference positions may be, for example, prism portions 1a and 1b which are not point-like, but are, for example, boundary positions W of optical surfaces.
May be a line segment corresponding to the boundary line. In this case, if the length of the line segment corresponds to the interval between the positioning adjustment points, it is possible to indicate the reference position with a single line segment.

The reference positions 14 and 15 are set for each lens array 2 at the position where the optical surface of the lens array 2 is formed (particularly,
(The boundary position of the optical surface). In this case, for example, only the lens array 2 is fixed to the fixed frame 2 in advance.
1 and with PBS1 not set, CC
A planar distribution of the amount of light by the microlenses formed in the lens array 2 is measured by a D camera or the like, and a reference position corresponding to an optical structure (not an outer peripheral portion) of the lens array 2 is determined based on the distribution. It can be configured to calculate.

In this embodiment, the light for observation may be used as transmitted light as described above.
It may be used as reflected light. That is, even if illumination is applied from the observation direction, there is no difference, and the same operation is obtained.

In the present embodiment, the optical surface of the PBS 1 is sufficiently visible to the naked eye. However, in order to grasp the positioning adjustment points P and Q more reliably, clearly, and accurately, the polarization characteristics of the PBS 1 (generally, (Optical characteristics). In this case, the prism 1a and the prism 1b can be distinguished from each other by the lightness by irradiating the PBS 1 with light containing only a polarization component in a specific direction. And become visible.

This is because the polarized light separating film 16 transmits only light having a polarized component in a predetermined direction, and when the irradiation light has only the polarized component in the same predetermined direction, a large amount of light is emitted from the prism portion 1b. In contrast, almost no light is emitted from the prism portion 1a configured to emit the reflected light from the reflective coating 17. On the other hand, the polarization separation film 1
When only the polarized component light which is reflected without being transmitted to 6 is irradiated, light is emitted from the prism 1a, but almost no light is emitted from the prism 1b. In addition, the boundaries can be clearly recognized.

(Second Embodiment) Next, an embodiment (second embodiment) of an optical element bonding apparatus according to the present invention will be described with reference to FIGS. FIG. 3 shows a schematic structure of the device of this embodiment as viewed from the side, and FIG. 4 shows a schematic structure of the device of this embodiment as viewed from the front. This embodiment is basically an apparatus for joining the same PBS 1 and lens array 2 as those used in the first embodiment.

In this embodiment, a mounting base 10 for positioning or fixing the PBS 1 and the lens array 2 is provided.
An observation illumination unit 30 housed inside the mount 10 for irradiating light when observing the PBS 1 and the lens array 2, a PBS 1 disposed above the mount 10, A camera unit 40 for observing the lens array 2, a light source unit 50 for irradiating the mounting base 10 with ultraviolet rays for curing the adhesive from below, and a PBS 1 loaded in the mounting base 10. Press unit 60 for pressing against lens array 2
It is roughly composed of

As shown in FIGS. 1 and 2, the mounting base 10 includes a fixing mechanism for fixing the lens array 2 and a position adjusting mechanism for positioning the PBS 1 mounted on the lens array 2. It is composed of The fixing mechanism is
Constituted on a base 19 supported by a strut 18,
A fixed frame 21 for fixing the lens array 2 similar to that of the first embodiment and a pressing cylinder 22 for pressing and fixing the lens array 2 against the fixed frame 21 are provided.

On the other hand, the position adjusting mechanisms are arranged on both left and right sides of the fixing mechanism, and are position adjusting units 24 and 25 which are configured to be movable in the x, y, and θ directions, respectively.
25, and an interlocking plate 2
6 and a positioning frame 11 for holding the PBS 1 shown in FIG.

The fixing mechanism and the position adjusting mechanism are PB
S1 and the lens array 2 are fixed at their outer peripheral portions, and the surfaces of the PBS 1 and the lens array 2 are vertically exposed. For this reason, light generated from the observation illumination unit 30 and the light source unit 50 described later is directly applied to the PBS 1 and the lens array 2, and the camera unit 40 described later is applied to the illumination emitted by the observation illumination unit 30. It allows direct observation of transmitted light.

The observation illumination unit 30 is arranged inside the support column 18 of the mounting base 10 and is configured to be movable in the front-rear direction along a guide rail 32 a formed on the base plate 32. Base 33 that slides on guide rail 32a
A guide rail 33a extending in a direction orthogonal to the guide rail 32a is formed on the upper side, and the illumination table 34 is configured to be movable in the left-right direction along the guide rail 33a. The base 33 is a cylinder rod 37 of the drive cylinder 37.
When the drive cylinder 37 is operated, it is configured to be able to move rearward from the inside position of the mounting base 10 along the guide rail 32a and retract.

On the lighting table 34, two light irradiators 35, 35 arranged on the left and right sides are mounted. These light irradiators 35 receive the light guided by the optical fiber 36, and receive the light therein. Light having a predetermined polarization direction is irradiated upward by the arranged polarizing plate.

The camera unit 40 disposed above the mounting base 10 has two imaging units 41, 41 arranged side by side.
Is provided, and the wiring cord drawn out from the imaging unit 41 is connected to a monitor (not shown). The imaging units 41 are attached to a common support 43 via an XY movement mechanism 42 that is configured to be movable in the plane direction.
The support body 43 is movably suspended in the front-rear direction with respect to the top plate 44, is connected to a cylinder rod 45 of a drive cylinder (not shown), and is movable between a photographing position shown and a rear retract position. It is configured.

The light source unit 50 disposed below the mounting base 10 comprises an ultraviolet lamp 51 and a condenser lens 52 disposed above the ultraviolet lamp 51.

The press unit 60 disposed above the mounting base 10 is lowered by a drive cylinder (not shown) from the upper retreat position to a pressing position where the PBS 1 loaded on the mounting base 10 is pressed. It is configured so that it can be pressed against the lens array 2.

The joining process according to the above embodiment is performed as follows. First, the lens array 2 is placed on a bottom plate (not shown) of the fixing mechanism of the mounting base 10, and its outer peripheral portion is brought into contact with the inner surface of the fixing frame 21. Next, press cylinder 2
2 is operated to press the lens array 2 against the fixed frame 21 to fix it. Next, a PBS 1 having a lower surface coated with a photocurable transparent resin is placed on the lens array 2. In this state, the PBS 1 is held between the positioning frame 11 and the holding arm 12.

Next, the observation illumination unit 30 and the camera unit 40 are extended to positions below and above the mounting base 10, and illumination light having predetermined polarization characteristics is directed upward from the light irradiation unit 35. To irradiate. The light irradiated from the light irradiation unit 35 may be ordinary visible light, but is preferably light having only one polarization component separated by the light separation surface formed by the polarization separation film 16 of the PBS 1. . In this way, in the image detected by the camera unit 40, the prism 1b from which the light transmitted through the polarization separation film 16 is emitted
Then, the contrast between the prismatic portion 1a from which the reflected light of the reflective coating is emitted becomes clear, and the boundary position W of the polarization separating film 16 or the reflective coating 17 as the optical surface is easily identified.

In the camera unit 40, the two imaging units 4
In areas 1 and 41, areas centered on the positioning adjustment points P and Q shown in FIG. 1 are photographed, and those images are displayed on a monitor (not shown). On this monitor, preset reference positions 14 and 15 shown in FIG. 1 are displayed as cross-line pointers. Here, by rotating dials of three micrometers in the x, y, and θ directions provided in the position adjustment units 24 and 25 of the positioning adjustment mechanism, the entire positioning adjustment mechanism is moved with respect to the fixed frame to perform positioning. The adjustment is performed so that the adjustment points P and Q coincide with the reference positions 14 and 15. Here, automatic adjustment is performed by inputting the positioning adjustment points 14 and 15 projected on the monitor by using coordinate input means such as a mouse and automatically operating the position adjustment units 24 and 25 by a stepping motor or the like. Is also possible.

Next, the observation illumination unit 30 and the camera unit 40 are retracted backward, the press unit 60 is lowered, and the PBS 1 positioned with respect to the lens array 2 mounted on the mounting base 10 is moved to a predetermined position. Press with pressure. In this state, the ultraviolet lamp 51 of the light source unit 50
Is turned on to cure the adhesive layer 23 between the PBS 1 and the lens array 2.

When the curing of the adhesive layer 23 is completed, the ultraviolet lamp 51 is turned off and the press unit 60 is retracted upward. Finally, the positioning frame 11 and the holding arm 12 holding the PBS 1 release the PBS 1 and release the lens array 2.
The fixing frame 21 and the pressing cylinder 22 that have fixed the lens array 2 also release the lens array 2.

According to the above embodiment, the same effects as those described in the first embodiment can be obtained in the positioning step of the optical element, and the fixing step and the bonding step of the optical element can be performed continuously. The effect that it can be obtained is obtained.

(Third Embodiment) Next, an apparatus according to a third embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 5 and 6, the apparatus of this embodiment is adapted to the case where two PBSs 1A and 1B are joined to the same lens array 2 as the first and second embodiments. is there. The two PBSs 1A and 1B are formed in a line-symmetrical structure, and are formed by bonding a plurality of prisms 1Aa, 1Ab or 1Ba, 1Bb to each other as described above.

In this embodiment, as shown in FIG. 6, since it is necessary to position the PBS 1A and the PBS 1B independently on the lens array 2, the edge of the boundary position W between the innermost optical surfaces is required. Two positioning adjustment points PA, PB, QA, and QB are provided in each section, and these positioning adjustment points are made to coincide with a reference position (not shown). The inner ends of the two PBSs 1A and 1B facing each other are designed with a margin in advance so as to be separated from each other with a small interval in order to enable independent positioning.

The lens array 2 is placed on a bottom plate 70 of a fixing mechanism having substantially the same configuration as that of the second embodiment, and two sides thereof are fixed by a flat L-shaped fixing frame 71. On the opposite side of the fixed frame 71, a smaller plane L
A pressing cylinder rod 72 having a U-shaped pressing portion 72a projects at a predetermined pressure, and the lens array 2 is sandwiched between the fixed frame 71 and the pressing portion 72a by the pressure of the pressing cylinder rod 72. It has become.

At the left and right sides of the above structure, the position adjusting units 7 are respectively provided.
As shown in FIG. 7, interlocking plates 75 and 76 extending in the horizontal direction are attached to the upper ends of these members. The interlocking plate 75 connected to the position adjustment unit 73 extends from the left side to the right side of the apparatus, and has a detoured plane so as to surround the PBSs 1A and 1B placed on the lens array 2 from both left and right sides. Conversely, the interlocking plate 76 connected to the position adjustment unit 74 extends from the right side of the device to the left side,
Again, the plane has a detour shape so as to surround the PBSs 1A and 1B from both left and right sides.

Two air sliders 77A, 77B, 78A, 7 are provided at the left and right ends of the interlocking plates 75, 76, respectively.
8B is attached, and positioning plates 79A, 79B, 79C, 79D are fixed thereon, respectively. The positioning plates 79A and 79B project in a tongue shape toward the inside, and the positioning plates 79C and 79D have an L-shaped fitting shape formed to receive one corner of the PBSs 1A and 1B.

The air sliders 77A, 77B, 78
The projecting pressure of A, 78B is set to a predetermined value in advance,
The positioning plates are moved inward at a pressure corresponding to the supplied air pressure, and the PBSs 1A and 1B are moved at their end faces.
Is to be clamped. The PBSs 1A and 1B gripped by the positioning plate are moved by the position adjusting unit 7
By adjusting 3, 74, the lens array 2 can be moved in the plane direction (x, y, θ directions).

As shown in FIG. 7, the bottom plate 70 of the fixing mechanism is supported by the support 80 as in the above-described embodiment.

In this embodiment, the case where two PBSs are joined to one lens array 2 is shown. However, by adjusting the position of each PBS based on the optical structure, high precision can be obtained in the same manner as described above. Can be positioned.

[0066]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect, the boundary position between the optical surfaces formed on one optical element is positioned so as to coincide with the reference plane position corresponding to the plane position of the other optical element. Optical positioning can be performed with higher precision than before, and the optical characteristics of the composite optical element can be improved. Further, unlike the related art, since it is not necessary to perform the alignment depending on the outer shape of the optical element, the accuracy of the outer shape of the optical element itself is not so required, and the processing cost and processing time of the optical element can be reduced.

According to the second aspect, the position can be adjusted by viewing from the side of the other optical element, but the boundary position can be adjusted by visually checking from the side of the optical element having the optical surface. It is possible to more clearly grasp, and it is possible to perform positioning with high accuracy.

According to the third or sixth aspect, by irradiating polarized light, the light amount ratio of two light beams separated on the light separating surface changes according to the polarization direction of the irradiated polarized light. Since the boundary position of the surface or the light separation surface can be more easily visually recognized, positioning can be performed with higher accuracy.

According to the fourth aspect, since the joining can be performed only by irradiating the light after the positioning is completed, the joining process and the joining equipment are simplified.

According to the fifth aspect, since the reference plane position displayed by the reference position display means and the boundary position in the plane image acquired by the image acquisition means can be compared, the optical position can be easily and accurately determined. The element can be positioned.

According to the seventh aspect, after the positioning is completed, the light-curing adhesive is cured by the light irradiating means while the first optical element and the second optical element are pressed against each other by the pressing means, so that the optical element can be precisely formed. Can be joined.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view for explaining a first embodiment of a method for bonding optical elements according to the present invention.

FIGS. 2A and 2B are a longitudinal sectional view for explaining the first embodiment and an explanatory view showing a structure of a polarizing beam splitter (PBS); FIGS.

FIG. 3 is a schematic configuration side view for explaining the structure of an optical element bonding apparatus (a second embodiment) according to the present invention.

FIG. 4 is a schematic configuration front view for explaining a structure of a second embodiment.

FIG. 5 is a schematic plan view showing a mounting structure of an optical element bonding apparatus (third embodiment) according to the present invention.

FIG. 6 is a schematic cross-sectional view illustrating a structure of a main part of a mounting portion according to a third embodiment.

FIG. 7 is a schematic longitudinal sectional view showing a mounting structure according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1A, 1B Polarization beam splitter 1a, 1b Prismatic prism part 2 Lens array 10 Mounting base part 11 Positioning frame 12 Holding arm 14, 15 Reference position 16 Polarization separation film (light separation surface) 17 Reflective coating (optical surface) 21 Fixed frame 22 Pressing Arm 24, 25 Position Adjusting Unit 26 Interlocking Plate 30 Observation Illumination Unit 40 Camera Unit 50 Light Source Unit 60 Press Unit 70 Bottom Plate 73, 74 Position Adjusting Unit 75, 76 Interlocking Plate 77A, 77B, 78A, 78B Air Cylinder 79A, 79B, 79C, 79D Positioning plate P, Q Positioning adjustment point

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B29C 65/48 B29C 65/48 B29L 11:00

Claims (7)

[Claims] 1. A joining method of an optical element for joining a first optical element and a second optical element, wherein at least one of the optical elements has a plurality of optical surfaces for determining optical characteristics, wherein the first optical element has a predetermined plane. And the second optical element is superimposed on the first optical element so that a boundary position formed by the optical surface is visible, and the boundary position is set to a plane position of the other optical element. Bonding the first optical element and the second optical element to each other and adjusting the planar position of the second optical element so as to match the corresponding reference plane position, and thereafter bonding the first optical element and the second optical element. Method. 2. The method according to claim 1, wherein the positioning is performed while visually recognizing the boundary position from the side of the first optical element or the second optical element having the optical surface. 3. The first optical element and the second optical element according to claim 1, wherein a light separating surface having a light transmission characteristic depending on a polarization direction is formed in the optical element having the optical surface. A method of joining optical elements, wherein the boundary position is easily recognized by irradiating polarized light and using transmitted light or reflected light. 4. The first optical element according to claim 1, wherein a light-curable adhesive is interposed between the first optical element and the second optical element, and light is emitted after positioning is completed. And bonding the second optical element to the optical element. 5. An optical element joining apparatus for joining a first optical element and a second optical element, wherein at least one of the optical elements has a plurality of optical surfaces for determining optical characteristics, wherein the first optical element has a predetermined plane. A fixing member for fixing the first optical element and the second optical element, and a positioning adjustment means for performing positioning adjustment in a state where the second optical element is superimposed on the first optical element; and the first optical element and the second optical element. Image acquisition means for visually recognizing a boundary position formed on the optical surface by light received from the light source, and a reference plane position corresponding to a plane position of the other optical element for matching the boundary position with the image. An optical element bonding apparatus, comprising: a reference position display unit for displaying the image in a state comparable to an image obtained by the acquisition unit. 6. The first optical element and the second optical element according to claim 5, wherein a light separating surface having a light transmission characteristic depending on a polarization direction is formed in the optical element having the optical surface. A polarization irradiating means for irradiating polarized light for facilitating visual recognition of the boundary position. 7. The device according to claim 5, wherein a pressing unit for pressing the first optical element and the second optical element to each other and an interposing member between the first optical element and the second optical element. And a light irradiation unit for curing the photocurable adhesive.