JPH0458214A - Polarized light generating optical device - Google Patents

Abstract

PURPOSE:To efficiently generate linearly polarized light by dividing the light from a light source to two linearly polarized light components by a polarizing beam splitter and rotating the plane of polarization of one of them by 90 deg. to join this component to the other. CONSTITUTION:The light of a light source 5 is collimated to parallel rays by a curved mirror 6 and is made incident at 45 deg. on a mirror type polarizing beam splitter 3, and the p-polarized light component is transmitted through a polarizing beam splitter 3 and is refracted by a first prism forming plate 2 and is emitted. The s-polarized light component is reflected by the polarizing beam splitter 3 and is reflected in the opposite direction by a prism reflection face 4, and thereby, this component has the plane of polarization rotated at 90 deg. and is converted to p-polarized light and is transmitted through the polarizing beam splitter 3 and is refracted by the first prism forming plate 2 and is emitted. Forms and refractive indexes of respective small prisms of the first prisms forming plate 2 are properly selected to make these two emitted light parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for converting a beam of light with random polarization characteristics into linearly polarized light.

[Prior Art J] For example, it is known that a linearly polarized light beam is useful as a light source for a liquid crystal projector, or for illumination where reflections of the light source are avoided (lighting through glass, lighting through water, etc.).

Such linearly polarized light is conventionally used as a light source with random polarization characteristics (
It is produced by passing the light from a tungsten lamp, halogen lamp, xenon lamp, metal paralite lamp, etc.) through a polarizing plate, but at this time, the component of the source light that is perpendicular to the polarization plane of the transmitted light is cut off. Therefore, the usable transmitted light is at most 50% of the light source light.

As described above, the method using a polarizing plate has a problem in that the loss is large.

One way to avoid this loss is to first split the source light into two linearly polarized components using a polarizing beam splitter, rotate one of the polarization planes by 90'', and then merge them into the other.

An example of realizing this idea is Japanese Patent Laid-Open No. 63-19791
Publication No. 3, Japanese Utility Model Publication No. 187101/1983, Japanese Patent Application Publication No. 1983
There are JP-A-3-271313, JP-A-63-150922, and JP-A-63-168622.

The above-mentioned Japanese Unexamined Patent Publication No. 197913/1983 and Utility Model Application No. 63-
In Japanese Patent No. 187101, one component separated by a polarizing beam splitter is reflected by two reflecting surfaces to rotate the plane of polarization. Rotating the plane of polarization by reflection in this manner is preferable in that there is no wavelength dependence, but the size of the apparatus increases in order to secure the optical path of the reflected light, which is not preferable in this respect.

Furthermore, the devices disclosed in Japanese Unexamined Patent Application Publication No. 63-271313 and Japanese Utility Model Application Publication No. 63-150922 are undesirable because of their large device size.

Furthermore, in the above-mentioned Japanese Patent Application Laid-Open No. 63-168622, a TN liquid crystal is used to rotate the plane of polarization, and the above function is achieved with a relatively small device and an extremely simple structure.
It is preferable in this respect. However, since the S-polarized light component reflected by the polarizing beam splitter and the P-polarized light component whose plane of polarization has been rotated after passing through the polarizing beam splitter are spatially separated to form the output beam, the beam width differs from that of the incident beam. In addition, since the polarization rotation component is slightly attenuated when passing through the liquid crystal layer, there is a drawback that the output beam has uneven brightness.

[Problems to be Solved by the Invention] The problems to be solved by the present invention are to improve the efficiency (when producing linearly polarized light from a beam of randomly polarized light, to increase the beam width (and to prevent uneven brightness in the output beam). The purpose is to provide a device that does not cause such problems.

[Means for Solving the Problems] The polarized light creating optical device according to claim 1 of the present invention provides polarized light that reflects one of the p-polarized component light and the S-polarized component light of the light from the light source and transmits the other. a beam splitter; a reflecting means for receiving reflected light from the polarizing beam splitter to obtain a reflected light component with a plane of polarization rotated by 90 degrees; a polarizing unit comprising a first prism forming plate having a prism row on one side for aligning and combining the light and the light directly transmitted through the polarizing beam splitter among the light from the light source; a reflecting surface that reflects at least a portion of the light synthesized by the first prism forming plate; and aligning the traveling direction of the reflected light from the reflecting surface and the other part of the light synthesized by the first prism forming plate. The polarization creating optical device according to claim 2, further comprising: a second prism forming plate for combining the light beams and having a prism row on one side; The polarization creating optical device described in 1. has a reflector that guides at least a portion of the light emitted from the polarization beam splitter to the first prism forming plate.

Further, the polarization creating optical device according to claim 3 is provided in claim 1.
It has a light beam combining section consisting of the two sets of polarizing sections described in , and a second prism forming plate which is for aligning and combining the traveling directions of the light from each polarizing section and having a prism row on one side. The polarized light creating optical device according to claim 4 is characterized in that in the polarized light creating optical device according to claim 1 or 3, the reflecting means has a plurality of adjacent reflecting mirror surfaces that are orthogonal to each other. The prism reflecting surfaces are arranged in large numbers in a direction orthogonal to the ridgeline formed by adjacent reflecting mirror surfaces, and are arranged so that the direction in which the reflecting mirror surfaces are arranged forms an angle of 45° with respect to the polarization plane of the incident light. The polarized light creating optical device according to claim 5 is characterized in that the polarized light creating optical device according to claim 4 is configured such that a phase plate is disposed in front of the reflecting means. The polarization creating optical device according to claim 6 is the polarization creating optical device according to claim 1 or 3, characterized in that the reflecting means is a combination of a wavelength plate and a plane mirror. .

Further, the polarization creating optical device according to claim 7 includes two polarization beam splitters that reflect one of the p-polarized component light and the S-polarized component light of the light from the light source and transmit the other; An wavelength plate placed between the polarizing beam splitters and the above two polarizing beam splitters.
The light that is reflected by each of the above, passes through the 1/2 wavelength plate, the polarization plane is rotated by 90 degrees, and is transmitted through the other of the above two polarizing beam splitters, and the light that is directly polarized among the light from the above light source. a polarizing section consisting of two first prism forming plates each having a prism array on one side for aligning and combining the light transmitted through the other beam splitter with the light traveling in the same direction;

two reflecting surfaces that reflect at least a portion of the light synthesized by each of the first prism forming plates, and combining the reflected light from the two reflecting surfaces in the same direction and/or reflecting the light from each reflecting surface; A second prism forming plate having a prism row on one side and for aligning and synthesizing the light and other parts of the light synthesized by the first prism forming plate corresponding to each reflecting surface, and having a prism row on one side. The polarization creating optical device according to claim 8 is characterized in that the polarization creating optical device has a light beam combining section of The polarization creating optical device according to claim 9 is the polarization creating optical device according to claim 1.3 or 7, wherein the polarizing beam splitter has a polarizing multilayer film between two transparent plates. Claim 10: A prism is formed by arranging a plurality of prisms sandwiched in parallel on the outer surface side of each transparent plate and having two surfaces that form an angle of 45° with the surface normal and are orthogonal to each other.
In the polarization creating optical device according to claim 1.3 or 7, the polarization beam splitter has a polarization multilayer film between one transparent plate and the slope of the right angle prism. is sandwiched between the prisms, and a plurality of prisms each having two surfaces forming an angle of 45 degrees with the surface normal and orthogonal to each other are arranged in parallel on the outer surface side of the transparent plate.

Furthermore, in the polarization creating optical device according to claim 11, the first prism forming plates are arranged symmetrically with respect to each other in the polarizing section according to claim 1 and/or the polarizing section according to claim 7. A plurality of prisms are arranged in such a manner that the first prism forming plate side of the polarizing part array aligns and synthesizes the traveling direction of the light emitted from the polarizing part, and has a prism row on one side. It is characterized in that second prism forming plates are arranged.

[Function] The polarization creating optical device of the present invention splits light from a light source into two linearly polarized components using a polarizing beam splitter, rotates one polarization plane by 90 degrees, and then merges it into the other. As a means for rotating the plane of polarization, a reflector or a transmitter having a function of rotating the plane of polarization by 90° is used.

First, a reflector having the function of rotating the plane of polarization by 90'' will be explained.

FIG. 19 is a principle diagram showing how a component whose polarization plane is rotated by 90'' is obtained by reflection on a prism reflecting surface.

The linearly polarized light 24 incident on the surface 26a is divided into an electric field vector component Fs parallel to the ridgeline of the prism and a perpendicular component Fp. If the surfaces 26a and 26b are perfect conductor reflecting surfaces, the electric field vectors 26a and 26b Component Fp' of light 25 reflected by
As a result, the polarization plane of light 25 is rotated by 90 degrees compared to light 24.

However, in reality, there is no reflective surface that is a perfect conductor.
Generally, a phase difference Δ is generated between Fs' and Fp', and the amplitudes of the two are also different, so that the reflected light 25 becomes elliptically polarized light.

Therefore, only the component whose polarization plane of this elliptically polarized light is orthogonal to that of the incident light is effective. Here, the smaller Δ, the closer the surface is to a perfect conductor and the higher the efficiency.

FIG. 18 shows an example of a prism reflective surface.

A large number of reflective mirror surfaces are formed on one side of the substrate 23, adjacent reflective mirror surfaces are orthogonal to each other, and a large number of reflective mirror surfaces are arranged in a direction perpendicular to the ridgeline formed by the adjacent reflective mirror surfaces. .

The reflecting mirror surface forms an angle of, for example, 45° with respect to the normal direction U of the substrate surface.Here, the condition that the adjacent reflecting mirror surfaces are orthogonal is such that the light incident along the normal direction U is reflected in the normal direction. This is a necessary condition, and it is most preferable in terms of efficiency that the angle between the reflecting mirror surface and the normal direction U is 45°.

The reflective mirror surface can be obtained by forming a predetermined shape on one side of the substrate 23 and then forming a metal layer by vapor deposition or plating, or by forming a dielectric multilayer film.
If a transparent material is used as the prism, the plane side can be used as the incident surface and the prism surface can be used as a back mirror. Furthermore, the substrate 2
If the refractive index of 3 is greater than 21'', the prism surface may be used as a total reflection surface.For reflective mirror surfaces made of metal layers or dielectric multilayer films, the above-mentioned differences may occur due to differences in the type of metal, film thickness, and design of the multilayer film. The phase difference Δ varies, but when total reflection of a prism is used, it can be calculated from the refractive index. For example, when the refractive index is 1.49 (polymethyl methacrylate), Δ=70°. From now on, 90 of the plane of polarization
'The rotated component is 67%, but total reflection yields nearly 100% reflectance, so the efficiency at the reflective surface is approximately 67%.
It becomes 7%.

Next, a method of rotating the plane of polarization by 90'' using a wavelength plate will be explained. FIG. 20 shows an example of a reflective surface using a wavelength plate. The incident light 17 passes through the wavelength plate 16 before and after being reflected by the reflecting mirror 18, thereby becoming reflected light 18 with its plane of polarization rotated by 90''.

The reflecting mirror used here may be a metal mirror or one using a dielectric multilayer film. Alternatively, a metal mirror or a dielectric multilayer film may be formed on one side of the wavelength plate to serve as a reflecting mirror.

In this method, since a wave plate is used, the plane of polarization is 90"
The efficiency of the rotated reflected light is wavelength dependent, which is not preferable when using white light.In order to reduce this wavelength dependence, birefringent materials with different wavelength dispersions are combined. An achromatic wave plate may also be used.

Note that by using the above two means together, the plane of polarization can be rotated more efficiently.

FIG. 21 is an example of a reflective surface using a phase plate 19 and a prism reflective surface 20. In the reflection by the prism reflecting surface, the reflected light becomes elliptically polarized light because the phase difference Δ between each component Fs' and Fpo of the reflected light is not O. The 0 phase plate 19 that cancels the phase difference and obtains linearly polarized light with a polarization plane rotated by 90'' passes through before and after reflection, so it is sufficient to use one with a retardation of -Δ/2.

In this case, since the phase difference to be provided by the phase plate is relatively small, the overall wavelength dependence is small and it can be sufficiently applied to white light. Any of the prism reflecting surfaces mentioned above can be used, but it is most preferable to use a total reflection prism, which has a high reflectance and allows easy calculation of Δ. For example, when using the polymethyl methacrylate prism described above, since Δ=70°, extremely high efficiency can be easily obtained over the entire visible light range using a phase plate that provides 35° retardation.

Next, a transmitting body having the function of rotating the plane of polarization by 90'' will be described.

An example of this is one that uses a 1/2 wavelength plate and transmits the incident light so that the angle between the polarization plane of the incident light and the optical axis of the 1/2 wavelength plate is 45°.

In this method, the plane of polarization is rotated regardless of the direction in which the light ray passes, so it can be used when an effect is required when passing light in both directions. However, since the effect is wavelength dependent,
This is not preferable when using white light.

The polarization plane rotation component obtained as described above and the other component separated by the polarization beam splitter are combined with the first prism forming plate so that their traveling directions are aligned. Then, the light beams emitted from the first prism forming plate are recombined in a light beam combining section including a second prism forming plate so as to reduce the total beam width. By doing this,
The beam width can be expanded by creating polarization.

Furthermore, by using a prism forming plate formed by arranging microprisms, it is possible to avoid uneven brightness in the emitted light beam.

[Example] The present invention will be explained in detail below.

FIG. 22, FIG. 23, FIG. 27, and FIG. 26 are all plan views of the embodiment of claim 1. These are claim 4,
This is also an example of No. 8.

In the embodiment shown in FIG. 22, the light from the light source 5 is made into parallel light by the curved mirror 6, and enters the mirror-type polarizing beam splitter 27 at an angle of 45 degrees, and the p-polarized light component is transmitted through the polarizing beam splitter 27. The light is refracted by the first prism forming plate 2 and output. On the other hand, the S-polarized component is transmitted through the polarizing beam splitter.
27 and reflected in the opposite direction by the prism reflecting surface 4, the polarization plane is rotated by 90° and converted into p-polarized light, which is then transmitted through the polarizing beam splitter 27 and the first
The light is refracted by the prism forming plate 2 and emitted.

Here, by appropriately selecting the shape and refractive index of each small prism of the first prism forming plate 2, the two emitted lights can be aligned in parallel. The polarizing beam splitter 27, the prism reflecting surface 4 and the first prism forming plate 2
The polarizing section is configured by:

Of the light emitted from the first prism forming plate 2 as described above, the light portion emitted from half of the first prism forming plate 2 enters the entire second prism forming plate 1 at an angle of 45°, and The light is refracted by the second prism forming plate 2 and output. Also, the first
The light portion emitted from the other half of the prism forming plate 2 is incident on the entire reflecting mirror 7 at an angle of 45 degrees, and is deflected by 9 G'' by reflection, and is incident on the entire second prism forming plate 1 at an angle of 45 degrees. The light enters, is refracted by the second prism forming plate 2, and is emitted.Here, by appropriately selecting the shape and refractive index of each small prism of the second prism forming plate 1, the two emitted light beams are made parallel to each other. The beam width of the light emitted from the second prism forming plate 1 is the same as the beam width of the incident light from the light source.The light beam combining section is formed by the reflecting mirror 7 and the second prism forming plate 1. configured.

FIG. 13 is a schematic diagram showing how light passes through the first prism forming plate 2 or the second prism forming plate 1. As can be seen from this figure, the light is directed in the normal direction of the prism forming plates 1 and 2. In order to emit the light, the angle θ that the small prism surface makes with the normal direction of the prism forming plate is calculated using the following formulas (1) and (2).
) should be selected so as to satisfy.

n5Lna=sinβ---(1)
n cos (α+θ) = cosθ + fist @(
2) Note that n here is the refractive index of the prism forming plate 1.2.

The above β is the angle of incidence on the prism forming plates 1 and 2, and is 45
°, so from the above equations (1) and (2), Sinα=17(n・21'2)...(3) tanθ
= (2n 2-1 ) +72-2 r/M,
, , (4) and θ>O, it can be seen from the above equation (4) that n > (3/2) "".

Preferably, θ is selected so that α≧θ.

If α less θ, as shown in Figure 17(a),
A portion 22 of the incident light 21 is reflected on the opposite inclined surface of the prism and changes direction, and does not become parallel outgoing light, which is undesirable as it leads to a decrease in efficiency. In order to prevent loss of light as shown in FIG. 17(b), from the above equation (3), t
ana = (sin”a/(1-sin”a))”
”= 17 (2n ” −1) Iix, and from α≧θ, tanα≧tanθ, and from these and the above formula (4), n≦ ((3+3′/”)/2)””=1 .538
・ ・ ・ (5) This is the preferable refractive index range of the prism forming plate. However, even if n is wider than the range of equation (5) above (so that light loss occurs as shown in FIG. 17(a), α → θ
If so, the efficiency will not drop sharply.

Furthermore, the smaller θ is, the larger the refraction angle is, and the greater the effect of expanding the spread angle of the light beam, which reduces the light collection efficiency, so from this point of view, it is selected so that the equality sign in equation (5) above holds true. It is better.

The embodiment shown in FIG. 27 differs from the embodiment shown in FIG. 22 only in the arrangement of the light source 5, curved mirror 6, and reflecting mirror 7, and the functions are the same.

The reflection 117 used in the embodiment shown in FIG. 22 and the embodiment shown in FIG. As shown in Figure 14, the refractive index is 21/2.
It is also possible to use a transparent plate as described above with a row of rectangular prisms formed on one side to form a total reflection mirror.

The embodiments shown in FIGS. 23 and 26 similarly utilize total reflection mirrors. In the embodiment of FIG. 26, the right angle prism 3
I am using 1 as is. In the embodiment shown in FIG. 23, a rectangular prism 9 in which a row of fine rectangular prisms are formed on the light exit surface is used as a light guide for all the light emitted from the first prism forming plate 2.

The mirror-type polarizing beam splitter used in the above embodiments is a transparent plate coated with multiple optical thin films, and separates the S-polarized light component and the P-polarized light component by taking advantage of their different reflectances. It is something. This type can cover a narrow wavelength band, so its use is limited to monochromatic light, but it has the advantage that it takes up only a small space because it is flat.

Next, FIGS. 29 and 30 are plan views of embodiments of claims 1 and 2. In these embodiments, a prism type polarizing beam splitter 29 is used. The prism-type polarizing beam splitter has a structure in which two right-angled prisms are bonded together with a polarizing multilayer film sandwiched between them, and can be used for a wide band that covers almost the entire visible light range, and can be applied to white light.

Note that the polarizing multilayer film referred to herein is a dielectric multilayer film formed by alternately laminating a material with a high refractive index and a material with a low refractive index such that the refraction angle is Brewster's angle.

In these embodiments, half of the light emitted from the two surfaces of the prism-type polarizing beam splitter 29 is
guided to the prism forming plate 2 (therefore, the two reflective #128
is used. Similar to the above-mentioned reflecting mirror 7, this reflecting mirror is the 14th reflecting mirror.
As shown in the figure, a transparent plate having a refractive index of 2171 or more with a row of right angle prisms formed on one side may be used, or the right angle prism 31 shown in FIG. 26 may be used.

Further, the embodiment shown in FIG. 30 takes advantage of the broadband property of the prism-type polarizing beam splitter, and uses two second prism forming plates 1 and gicroic mirrors 30a and 30b to achieve further color separation. It has a function. for example,
If 30a is a mirror that transmits red and reflects green and blue, and 30b is a mirror that transmits green and blue and reflects red, red and cyan polarized light can be obtained, respectively.

Next, FIGS. 1 and 4 are plan views of the embodiment of claim 1.9, and the mirror type polarizing beam splitter 27 of the embodiment of FIGS. 22 and 23 is replaced with that of FIG. 15, respectively. This is a replacement for a polarizing beam splitter.

As shown in FIG. 15, the polarizing beam splitter 3 in FIG. 1 and FIG. This is the same as that of a prism type polarizing beam splitter. The surface of each prism formed on a transparent plate functions in the same way as the incident surface and reflection surface of a prism-type polarizing beam splitter, and as a result, it exhibits the same function as a prism-type polarizing beam splitter. When applied to coherent light such as laser light, it disturbs the coherence and is undesirable, but there is no problem when used as an incoherent light source as in the present invention. Furthermore, as can be seen from FIGS. 1 and 4, it can be used at an incident angle β=45@, and can be used in almost the same way as the mirror type.

Next, FIGS. 2 and 3 are plan views of embodiments according to claims 1 and 10, and FIG. 9 is a perspective view of the embodiment of FIG. 2.

In these embodiments, the polarizing beam splitter 8 shown in FIG. 16 is used.

The polarizing beam splitter 8 is a prism-type polarizing beam splitter in which half is replaced with a transparent plate having a row of right-angled prisms, and its function is the same as that of the prism-type polarizing beam splitter. In the embodiment shown in FIGS. 2 and 3, the two sides of the polarizing beam splitter 8 face the light source 5 and the prism reflecting surface 4, respectively, and the right-angle prism functions as a light guide.

The method for manufacturing the polarizing beam splitter shown in FIGS. 15 and 16 above is basically the same as that for the prism type, in which a polarizing multilayer film is formed by vapor deposition on one transparent plate or a transparent block having a prism. Just glue the other transparent plate or transparent block.

Next, FIG. 24 and FIG. 28 are both plan views of the embodiment of claim 3. These are also embodiments of claim 4.8.

In the embodiment shown in FIG. 24, the two polarizing sections in the embodiment shown in FIG. 22 are arranged symmetrically so that the emitted light from both faces inward. The second prism forming plate 1 is disposed at a position where the emitted light from these two polarizing parts overlaps, and is combined into parallel light here.

According to this embodiment, the reflecting mirror 7 is omitted compared to the case in which two of the embodiments shown in FIG. In order to obtain the area, the total volume only needs to be about half.Furthermore, this embodiment has a mixing effect in which the lights at different positions on the left and right sides of the incident light beam are combined on the output surface. It has the function of reducing light intensity unevenness within the cross section.

The embodiment shown in FIG. 28 differs from the embodiment shown in FIG. 24 in the arrangement of the light source 5, curved mirror 6, and prism reflecting surface 4.
It combines the polarization of light from two light sources. Since the light from both light sources spreads on the output surface and is emitted, even if one of the light sources is turned off, the distribution of the emitted light beam will hardly change, and only the intensity will decrease. Using this property, you can change the intensity of the light into 2 to 3 levels (for example, if you use a strong and weak light source, you can switch it to 3 levels: [weak only] < [strong only] < [weak 10 strong]) Or, by setting two light sources of different colors, you can change the hue of the emitted light.

Next, FIG. 25 is a plan view of an embodiment according to claims 7 and 8.

In this embodiment, the two devices of the embodiment shown in FIG. has been done.

The light source 5, curved mirror 6, and second prism forming plate 1 are commonly used.

According to this embodiment, the size can be reduced to the same extent as the embodiment shown in FIG. 24 above.

FIG. 5 is a plan view of an embodiment of claim 3, 4.10,
6 and 7 are both plan views of an embodiment of claim 7.10.

In these embodiments, the polarizing beam splitter 8 shown in FIG. 16 is used, and the same size reduction as in the case of using a mirror type polarizing beam splitter is possible.

In the embodiment shown in FIG. 7, the second embodiment of the embodiment shown in FIG.
By changing the position of the prism-forming board, the light from the left and right polarizing sections is mixed, increasing the mixing effect.

Note that in the above embodiments, a phase plate may be placed in front of the prism reflecting surface (thereby, the embodiment of claim 5 can be obtained, and the prism reflecting surface 4 may be replaced with a combination of a wavelength plate and a plane mirror). Thus, an embodiment of claim 6 can be obtained.

Next, an embodiment of claim 11 is shown in FIG.

This embodiment is a development of the concept of claims 3 and 7, and by arranging a plurality of polarizing parts according to claim 1 and/or polarizing parts according to claim 7, the same emitted light cross section can be obtained. It is possible to reduce the overall volume required to obtain the polarization of light, and is particularly effective when obtaining wide polarization of light.

For example, in the embodiment shown in FIG. 8, two polarizing sections of the embodiment shown in FIG. 6 are arranged in parallel in the center, polarizing sections of the embodiment shown in FIG. A forming plate 1 is arranged. In order to obtain the same emitted light cross section,
The volume may be about 1/3 that of the embodiment shown in FIGS. 5 and 6, and about 1/6 that of the embodiment shown in FIGS. 1-4. In this embodiment, unlike the embodiment in FIG. 6 and the embodiment in FIG. The number will also decrease.

In this way, the prism forming plate of the component of the device of the present invention,
By making the prism reflecting surface, polarizing beam splitter, etc. as thin as possible for accuracy and strength, the number of components arranged in the same width can be increased and the thickness of the device can be made thinner.

FIG. 10 shows a part of an embodiment of claim 11.

In this embodiment, a plurality of polarizing sections B and light beam combining sections A are repeatedly arranged. FIGS. 12(a) to (f) show specific examples of the polarizing section B, and FIG. 11(a) shows specific examples of the light beam combining section A.
~(d). In these figures, the same members as in the above embodiment are given the same reference numerals.

In the example of the polarizing section B, 12 is a residual liquid long plate, and 13 is a plane mirror. In addition, when using a combination of the % wavelength plate 12 and the plane mirror 13, a half mirror may be used instead of the plane mirror 13 as long as the optical axes of both wavelength plates 13 are aligned. In this case, two wavelength plates act as wavelength plates.

In the example of the light beam combining section A, 9W is one in which two adjacent light guides 9 are integrated.

The difference between (b) and (C) is in the mixing effect, and (b)
As in (a), the lights from adjacent polarization sections mix together, whereas in (c), as in A of FIG. 10, they do not mix. Furthermore, in (d), a half mirror 11 is installed in the light guide in order to obtain a greater mixing effect.As can be seen from Figure 0, a large number of lights from different positions of the polarizing section are mixed together to form the output light. It consists of By doing this, it is possible to reduce the unevenness of the incident light. This uniformity effect is greatly influenced by the size of the repeating units A and B in FIG. 10, and a particularly large effect can be obtained when the repeating units A and B in FIG.

In the explanatory drawings of the present invention, a beam light source using a curved mirror is used as a light source, but it goes without saying that the same applies to a beam light source using a lens.

[Effects of the Invention] As explained above, the device of the present invention makes it possible to efficiently generate linearly polarized light from a randomly polarized light source using a small and simple device without expanding the beam width. I made it.

[Brief explanation of the drawing]

1 to 8 and 22 to 30 are all plan views of the polarization creating optical device of the present invention. FIG. 9 is a perspective view of the polarization creating optical device of the present invention. FIG. 10 is a plan view of a part of the polarization creating optical device of the present invention, and FIGS. 11 and 12 are diagrams showing specific examples of the light beam combining section A and polarizing section B, respectively. FIG. 13 and FIG. 17 are both diagrams showing the state of light passing through the prism forming plate. FIG. 14 is a diagram showing an example of a reflecting mirror. FIGS. 15 and 16 are diagrams showing polarizing beam splitters. FIG. 18 is an explanatory diagram of a prism reflective surface used in the polarization creating optical device of the present invention, and FIG. 19 is a diagram explaining the function of the prism reflective surface. FIGS. 20 and 21 are diagrams showing an example of a reflecting surface formed by a combination of a residual liquid elongated plate and a plane mirror, and an example of a reflecting surface formed by disposing a phase plate in front of a prism reflecting surface, respectively. Note that among the light rays in the figure, the p-polarized light component is shown by a solid line, and the s-polarized light component is shown by a dotted line. 1: Second prism forming plate, 2: First prism forming plate, 3.8, 27: Polarizing beam splitter-4, 20 nibrism reflecting surface, 5: Light source, 6: Concave mirror, 7.28: Reflecting mirror, 9: Light guide, 10: H wavelength plate 11: Half mirror, 12, 16: Figure wavelength plate, 13.15: Plane mirror, 14: Polarizing multilayer film, 13.15: Plane mirror, 17.21.24: Incident light, 18. 25: Reflected light, 19: Phase plate, 22: Loss light, 26a, 26b: Reflective surface, 30a, 30b: Dichroic mirror - 31 = Right angle prism. Agent Patent Attorney Minoru Yamashita Child 1 Figure 2 Figure 3 Figure 4 Figure ↑ ↑ ↑ Figure Figure I Figure Figure I Figure Figure (b) Figure (b) ) ■Figure■U-1110Figure 22Figure 23Figure 24Figure 25Figure 20Figure 28N

Claims (1)

[Scope of Claims] (1) A polarizing beam splitter that reflects one of the p-polarized component light and the s-polarized component light of the light from the light source and transmits the other, and a polarized beam splitter that allows the reflected light from the polarized beam splitter to be incident. a reflecting means for obtaining a reflected light component whose polarization plane has been rotated by 90 degrees; a light reflected by the reflecting means that is transmitted through the polarizing beam splitter; and a light that is directly transmitted through the polarizing beam splitter among the light from the light source. a polarizing section comprising a first prism forming plate having a prism row on one side for aligning and synthesizing the light in the traveling direction; and a reflecting surface for reflecting at least a part of the light synthesized by the first prism forming plate. and a second prism forming plate having a prism row on one side and for aligning and synthesizing the light reflected by the reflecting surface and the other part of the light synthesized by the first prism forming plate. A light beam combining section comprising: (2) The polarization creating optical device according to claim 1, further comprising a reflector that guides at least a portion of the light emitted from the polarization beam splitter to the first prism forming plate. (3) Light comprising two sets of polarizing sections according to claim 1 and a second prism forming plate having a prism row on one side and for aligning and synthesizing the traveling directions of light from each polarizing section. 1. A polarization creating optical device, comprising a beam combining section. (4) The reflecting means has a large number of adjacent reflecting mirror surfaces arranged in a direction orthogonal to each other and a ridge line formed by the adjacent reflecting mirror surfaces, and the reflecting means has a plurality of reflecting mirror surfaces arranged in a direction orthogonal to the ridge line formed by the adjacent reflecting mirror surfaces, and the reflecting means 4. The polarization creating optical device according to claim 1, wherein the polarization creating optical device is a prism reflecting surface arranged such that the mirror arrangement direction forms an angle of 45 degrees. (5) The polarization creating optical device according to claim 4, further comprising a phase plate disposed in front of the reflecting means. (6) The polarization creating optical device according to claim 1 or 3, wherein the reflecting means is a combination of a quarter wavelength plate and a plane mirror. (7) Two polarizing beam splitters that reflect one of the p-polarized component light and the s-polarized component light of the light from the light source and transmit the other, and a 1/2 polarized beam splitter that is placed between these two polarized beam splitters. Light that is reflected by the wavelength plate and each of the two polarizing beam splitters, passes through the half-wave plate, the plane of polarization is rotated by 90 degrees, and is transmitted through the other of the two polarizing beam splitters, and from the light source. a polarizing unit consisting of two first prism forming plates each having a prism array on one side, for aligning and combining the light that has directly passed through the other of the two polarizing beam splitters, out of the light; two reflecting surfaces that reflect at least a portion of the light synthesized by each of the first prism forming plates, and combining the reflected light from the two reflecting surfaces in the same direction and/or reflecting the light from each reflecting surface; A second prism forming plate having a prism row on one side and for aligning and synthesizing the light and other parts of the light synthesized by the first prism forming plate corresponding to each reflecting surface, and having a prism row on one side. What is claimed is: 1. An optical device for creating polarized light, comprising: a light beam combining section; (8) The polarization creating optical device according to claim 1, 3 or 7, wherein the polarization beam splitter is of a mirror type. (9) The polarizing beam splitter has a polarizing multilayer film sandwiched between two transparent plates, and a prism having two surfaces that make an angle of 45 degrees with the surface normal and are orthogonal to each other on the outer surface of each transparent plate. 8. The polarization creating optical device according to claim 1, wherein the optical device is formed by arranging a plurality of them in parallel. (10) The polarizing beam splitter has a polarizing multilayer film sandwiched between one transparent plate and the slope of a right-angled prism, and the polarizing multilayer film is formed on the outer surface side of the transparent plate at an angle of 45° with the surface normal, and is orthogonal to each other. 8. The polarization creating optical device according to claim 1, wherein the polarization creating optical device is formed by arranging a plurality of prisms having two surfaces in parallel. (11) The polarizing portion according to claim 1 and/or claim 7
A plurality of the polarizing parts described in 1 are arranged in such a manner that adjacent first prism forming plates are arranged symmetrically with respect to each other, and the polarizing parts are emitted from the polarizing parts to the first prism forming plate side of the polarizing part arrangement. What is claimed is: 1. A polarization creating optical device, characterized in that a second prism forming plate is arranged to align and synthesize the traveling directions of the light beams, and has a prism row on one side.