KR101472893B1 - A stereoscopic image projection device - Google Patents

Abstract

The present invention relates to a stereoscopic image projection device and, more specifically, to a stereoscopic image projection device capable of improving brightness. To achieve the objective, the present invention includes a light divider which allows incident light to pass through in one direction depending on polarization components and reflects the light into at least two different directions; a reflection member which reflects the light reflected by the light divider towards a screen; a prism which is placed near the light divider and through which the incident light into the light divider and the light penetrated through or reflected by the light divider pass; and a substrate which is placed on the prism and guides the incident light towards the prism to prevent energy loss due to gaps generated during the placement of the prism.

Description

A stereoscopic image projection device

The present invention relates to a stereoscopic image apparatus, and more particularly, to a stereoscopic image apparatus whose brightness can be improved.

1, in the optical splitter used in the stereoscopic image apparatus according to the related art, when the light in which the P-polarized light and the S-polarized light are mixed is incident on the optical splitter 1, the P- And the S-polarized light is reflected.

The reflected S-polarized light is reflected by the prism 2 provided on the upper side of the light splitter 1, is transmitted, and then passes through the half-wave retarder 4.

This causes the S-polarized light to be converted into P-polarized light, and then proceeds to the screen.

On the other hand, the P-polarized light transmitted through the light splitter 1 passes through the prism 3 provided below the light splitter 1 and proceeds to the screen.

As a result, the light in which the P- and S-polarized light are mixed by the light splitter 1 becomes the same polarized light (for example, P-polarized light) and can proceed in the same direction.

However, in order to apply such a technique to a stereoscopic image device, the following conditions are required.

The image of the light emitted from the projector has a predetermined size. The size of the image on the screen due to the light traveling along the transmission path and the size of the image on the screen due to the light traveling along the reflection path are overlapped with each other The stereoscopic image with high efficiency and high quality is realized on the screen.

The operation principle of a stereoscopic image apparatus using a conventional light splitter to increase the light utilization efficiency is as disclosed in US 7,857,455.

As shown in Fig. 2, light emitted from the image plane 5, which generates an image in the projector, is divided into light having two polarization components in the light splitter 7 via the projection lens 6.

That is, light having S-polarized light and P-polarized light components is reflected and transmitted by the light splitter 7.

The light having the reflected S-polarized light component is reflected by the reflecting member 9 and then passes through the half-wave retarder 8 and becomes P-polarized light, and is converged on the screen 11 via the modulator 13 .

The modulator 13 can change the polarization state by an electrical signal.

On the other hand, the light of the P-polarized component transmitted through the light splitter 7 reaches the screen 11 after passing through the modulator 12. Therefore, light mixed in the polarization direction emerging from the image plane 5 is driven by the modulators 12, 13 in one P-polarization state, and then directed to the screen 11. [

The divergence origin of the reflected light is the reflected light image plane 10, which has a distance difference between the image plane 5 of transmitted light and d ₁ .

Therefore, the size and height of the transmitted light and the reflected light on the screen 11 are d ₄ and d ₅ , respectively, and are different from each other, so that they are difficult to use as they are.

The above technique is improved, and a method of matching the images of the reflected and transmitted light with each other on the screen 11 is as follows.

In FIG. 2, let it be assumed that the optical axis of the light reflected and transmitted by the light splitter 7 forms an angle? ₁ on the screen 11. If the value of θ ₁ is very small or the distance d ₃ from the light splitter 7 to the screen 11 is much longer than the distance d ₂ from the light splitter 7 to the reflecting member 9, The distance between the image plane 5 and the reflected light image plane 10 is approximately equal to the distance d ₂ from the light splitter 7 to the reflecting member 9. [

Due to this difference, the size and height d ₄ of the light transmitted by the light splitter 7 and the reflected light on the screen 11 are always smaller than d ₅ .

It is preferable that the transmitted light and the reflected light are basically the same size on the screen 11 so that the image can be seen clearly.

3A is a graph showing the relationship between the height d ₄ of the light transmitted through the light splitter 7 on the screen 11 and the height of the transmitted light on the screen 11 by the light reflected by increasing the size of the image using the lens 14 It is a way to go to d ₅ .

However, since the magnification of the lens 14 must be different from the distance d ₃ between the optical splitter 7 and the screen 11, many kinds of lenses are prepared according to the condition of each theater, It must correspond to the distance d ₃ .

In addition, although it is possible to reduce the number of lenses by using a zoom lens, the number of individual lenses of the zoom lens should be limited to 2 to 3 due to factors such as transmittance, size, and price. Therefore, even if the zoom position is adjusted corresponding to each projection system, Of the zoom lens.

Therefore, a lot of design, manufacture and maintenance personnel of the lens 14 are required.

Another disadvantage is that the curvature of the lens 14 and the material of the lens are limited, so that the diameter of the lens 14, that is, the effective diameter, is also limited.

This means that it is practically difficult to use when the divergence angle of the light emitted from the projection lens 6 is large, and thus it is applicable only to an image system having a relatively small divergence angle.

3B shows a method of using a reflecting member 15 such as a mirror having a predetermined curvature instead of the lens 14. In this case, the curvature of the reflecting member 15 is about 5 Km, The difference in optical axis between the optical axis of the reflective member 15 and the reflected light is increased, so that the aberration is increased and the focus adjustment is not easy, so that the image is distorted on the screen 11, making it difficult to use.

On the other hand, another example of the technique of separating the conventional polarized light and then combining the polarized light in the same direction is shown in Japanese Patent Application Laid-Open No. 5-316091, and its specific structure is shown in Fig.

In Fig. 4, the P-polarized light is transmitted and the S-polarized light is reflected by the light splitter 18 provided between the optical members 17 and 19 such that the light in which the P-polarized light and the S-polarized light are mixed is applied to the prism.

The P-polarized light is transmitted and the S-polarized light is reflected by the light splitter 21 provided between the other optical members 16 and 17.

The reflected S-polarized light is converted into P-polarized light by the half-wave retarders 20 and 22, respectively.

According to the configuration of FIG. 4, the P-polarized light is theoretically transmitted at all, but the S-polarized light is divided and reflected at the diameter of the incident light. (E.g., P-polarized light) and used in a liquid crystal display device.

An object of the present invention is to provide a stereoscopic image apparatus for improving the quality and brightness of a stereoscopic image projected on a screen.

Another object of the present invention is to provide a stereoscopic image apparatus which can make the size of the apparatus more compact than the prior art.

According to an aspect of the present invention, there is provided a polarization beam splitter including a light splitter for transmitting incident light in one direction according to a polarization component and reflecting the light in at least two different directions,

A reflecting member for reflecting the light reflected by the light splitter in the screen direction;

A prism disposed around the light splitter and through which light transmitted through the light splitter and light split by the light splitter are transmitted; And a substrate disposed on the prism and guiding the incident light to the prism to prevent loss of light energy due to a tolerance generated when the prism is disposed.

According to the present invention, the size of the image due to the reflected light and the size of the image due to the transmitted light can be the same, thereby improving the image quality and brightness on the screen.

In particular, by disposing the substrate in front of the prism, it is possible to suppress the light loss that may occur due to the spacing space formed on the incident surface of the prism.

Furthermore, by disposing the refractive member in front of the substrate in addition, it is possible to prevent light from disappearing at the portion by blocking light from entering into the spacing space formed in the incident surface of the prism.

Further, by arranging the lens in the transmission path or arranging the reflecting member-prism assembly in the reflecting path, it is possible to match the image by the reflected light and the image by the transmitted light, thereby realizing a high quality stereoscopic image.

1 is a side view of a conventional stereoscopic image apparatus.
2 is a side view showing movement of light in a conventional stereoscopic image apparatus.
3A and 3B are side views illustrating the movement of light in a modified stereoscopic image apparatus according to the related art.
4 is a side view of a stereoscopic image apparatus according to another conventional art.
5 is a side view showing movement of light in a stereoscopic image apparatus as a basis of the present invention.
FIGS. 6A and 6B show a state in which the prism is separated from the prism in the present invention.
FIG. 7 illustrates a state where a substrate is attached to a prism in the present invention.
8 is a side view illustrating movement of light in a stereoscopic image apparatus to which a prism, a substrate, and a transmission path lens according to FIG. 7 are applied.
FIG. 9 is a side view illustrating the movement of light in a stereoscopic image apparatus to which a prism, a substrate, and a reflective member-prism assembly according to FIG. 7 are applied.
Fig. 10 shows that the refractive member is included in the embodiment of Fig.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

5, the stereoscopic image apparatus according to the present invention includes a light splitter 34, 35 for reflecting or transmitting incident light according to a polarization component, a light splitter 34, 35 provided outside the light splitter 34, 35, Prisms 23, 24 and 25 arranged so as to surround the light sources 34 and 35 and reflection members 26 and 27 for reflecting the light reflected by the light splitters 34 and 35 toward the screen 33 .

Behind the reflective members 26 and 27 are half-wave retarders 28 and 31 for converting light directed to the screen into other polarization components (for example, S-polarized light into P-polarized light) (For example, modulating linearly polarized light into circularly polarized light) is provided.

The light splitters 34 and 35 are composed of two light splitters arranged obliquely. For convenience, the first optical splitter 34 and the second optical splitter 35 are defined. The first light splitter 34 and the second light splitter 35 are arranged at a predetermined angle.

The P-polarized light incident on the first light splitter 34 is transmitted through the first light splitter 34 and the S-polarized light is reflected downward.

The P-polarized light incident on the second light splitter 35 is transmitted through the second light splitter 35, and the S-polarized light is reflected upward.

On the other hand, the prisms 23, 24, and 25 are a plurality of unit prisms, and the light dividers 34 and 35 are disposed therein.

Particularly, a first light splitter 34 is coated on the interface (bonding surface) between the first unit prism 23 and the second unit prism 24, and the third unit prism 25 and the second unit And the second light splitter 35 is coated and positioned on the interface (junction surface) between the prisms 24 as well.

Light that is incident on the light dividers 34 and 35 passes through the incident surface of the prisms 23 and 25 before entering the light dividers 34 and 35.

The light reflected or transmitted by the light splitters 34 and 35 passes through the exit surface of the prisms 23, 24, and 25 and is emitted.

Here, the light reflected by the first light splitter 34 should not interfere with the incident surface of the first unit prism 23 and the light output surface of the second unit prism 24, and the second light splitter 35 The reflected light should not interfere with the incident surface of the third unit prism 25 and the exit surface of the second unit prism 24.

For this purpose, the angle? ₁ between the two sides of the second unit prism 24 is preferably smaller than 90 degrees.

The angle? ₂ between the incident surface of the first unit prism 23 and the light reflected by the first light splitter 34 and the angle of incidence of the third unit prism 25, ( ₂ ) between the light reflected from the light source (35) should be at least 0.1 degree.

On the other hand, when the light reflected by the first light splitter 34 passes through the first unit prism 23, the exit surface of the first unit prism 23 functions as a flat plate so that refraction occurs and no additional aberration is generated do.

This condition is also applied when the light reflected by the second light splitter 35 passes through the third unit prism 25.

For this purpose, it is preferable that the angle (? ₃ ) formed by the incident surface and the emitting surface of the first unit prism (23) and the angle? ₁ formed by the two sides of the second unit prism (24) (? ₁ =? ₃ )

The angle? ₃ formed by the incident surface of the third unit prism 25 and the exit surface is preferably equal to the angle? ₁ formed by the two sides of the second unit prism 24 θ ₁ = θ ₃ ).

Under the above configuration, the light passing through the light splitters 34 and 35 is projected onto the screen 33 through the first modulator 30.

The light reflected by the light dividers 34 and 35 passes through the second and third modulators 29 and 32 and is projected on the screen 33 and overlapped on the screen 33 with the light passing through the transmission path .

FIG. 6A shows a case where each unit prism constituting the prism is separated, and FIG. 6B shows a case where each unit prism is bonded.

6A, angles θ ₅ , θ ₆ , and θ ₇ are formed when unit prisms are manufactured.

Here, the angle of incidence is defined as an angle formed between the incident surface and the bonding surface (surface bonded to the second unit prism) in the case of the first and third unit prisms 23 and 25.

In the case of the second unit prism 24, it means an angle formed between two bonding surfaces (a surface in contact with the first unit prism and a surface in contact with the third unit prism) except for the emission surface.

 These angles may have a predetermined tolerance < RTI ID = 0.0 > 8 < / RTI >

In the case of manufacturing the unit prisms each using an optical material, fine errors may occur even if the precision of the processing is increased.

6B, the theoretical angle of the angle [theta] ₈ between the incident surface of the first unit prism 23 and the incident surface of the third unit prism 25 should be 180 [deg.], the included angle (θ ₇₎ and a second unit-prism portion 24 of the included angle (θ ₆₎ and a third included angle actual angle of the summed angle (θ ₅₎ of the unit prisms 25 is 180 ° ± δ ° can be have.

If such a tolerance occurs, the incidence plane of the first unit prism 23 and the incidence plane of the third unit prism 25 can be flared or overlapped, whereby the light passing through the incidence plane can be influenced The image quality of the image implemented on the screen may be deteriorated.

When the distance from the projector to the screen is L, if the overlapping distance is Δ, then Δ≈L * Tan (δ).

For example, in the case of L = 25 m and? = 3 '(seconds), DELTA? 22 mm is obtained, which makes it practically difficult to use.

This tolerance 3 'is the degree of precision machining that is possible at present. For example, even if the precision machining is performed with delta = 1', the deviation of the screen is about 7 mm, which makes it difficult to use.

7, it is preferable that the substrate 36 be disposed over the incident surface of the first unit prism 25 and the incident surface of the third unit prism 23, as shown in Fig.

The substrate 36 is preferably made of a transparent optical member through which light is transmitted and is provided in the form of a flat plate.

The substrate 36 covers a gap formed between the incident surface of the first unit prism 23 and the incident surface between the third unit prism 25 to prevent light from directly entering the corresponding gap portion Thereby preventing loss of light energy in that portion.

Here, the loss of light energy means a change in the path of light that is unexpected, such as light scattering, diffuse reflection, refraction, extinction, and the like.

The refractive index of the substrate 36 is preferably the same or substantially the same as the refractive index of the prisms 23, 24 and 25 because the additional refraction between the substrate 36 and the prisms 23, .

The light passing through the substrate 36 is incident on the first and third unit prisms 23 and 25 and is then incident on the optical splitters 34 and 35 to be incident on the optical splitter 34 , 35, or can be transmitted through the optical splitters (34, 35).

 A separate adhesive layer 37 is formed so that the substrate 36 can be disposed on the incident surface of the first unit prism 23 and the incident surface of the third unit prism 25 so that the substrate 36 can be stably So that it can be positioned.

It is preferable that the material constituting the adhesive layer 37 be suppressed from generating aberration by using a transparent adhesive material having the same or similar refractive index as that of the first and third unit prisms 23 and 25 and the refractive index of the substrate 36 Do.

FIG. 8 shows a method for eliminating the difference between the size d ₆ of the image due to the transmitted light and the size d ₇ of the image due to the reflected light in the system shown in FIG.

In the embodiment of FIG. 8, it is proposed to enlarge the image by the transmitted light and to implement the same as the image size of the reflected light.

For this purpose, a lens 37 is disposed on the path of the light transmitted through the light splitters 34 and 35 and the second unit prism 24 to adjust the size of the image by the transmitted light.

9 is generated when the difference between the size (d ₇₎ of the image according to the size (d _6), and a reflected light image by transmitted light in the system shown in FIG. 5, illustrating another method for eliminating this difference.

In the embodiment according to FIG. 9, it is proposed to reduce the image due to the reflected light to realize the same image size as the transmitted light.

To this end, a reflective member-prism assembly (38, 39) having a reflective member and a prism at the same time is disposed instead of a reflective member such as a simple mirror on the path of reflected light.

Therefore, the light reflected by the light dividers 34 and 35 and passed through the first and third unit prisms 23 and 25 passes through the reflecting member-prism assemblies 38 and 39, The size of the image due to the transmitted light can be reduced.

Meanwhile, FIG. 10 shows a method of increasing the light efficiency as compared with FIG. 5, FIG. 7, FIG. 8, and FIG.

In Fig. 7, when each unit prism is joined, the vertexes of the unit prisms are gathered in the circular part indicated by the dotted line.

In particular, a fine space may be formed on the boundary between the incident surface of the first unit prism 23 and the incident surface of the third unit prism 25, and the size of the spacing space is defined as t ₁ .

t ₁ is usually 0.1 to 0.2 mm. In this case, the light passing through this spacing space is scattered and there is a loss of light.

In order to prevent such light loss, it is proposed to arrange the refractive members 40, 41 in front of the substrate 36.

When the first and second bending members 40 and 41 are defined by the first bending member 40 and the second bending member 41 for convenience sake, Is preferably not more than 180 degrees (in a planar state), more preferably not more than 180 degrees.

That is, the mutual arrangement angle between the incident surface of the first refraction member 40 and the incident surface of the second refraction member 41 is preferably smaller than 180 degrees, and the exit surface of the first refraction member 40 and the second refraction member It is preferable that the mutual arrangement angle between the exit surfaces of the member 41 is larger than 180 degrees.

If it is assumed that the refractive members 40 and 41 are made by bending a flat optical member, the bending angle may be seen to be less than 180 degrees in the entrance plane and 180 degrees in the exit plane.

In the case of the connecting portion between the first and second folding members 40 and 41, there may be no gap or a minute gap t ₂ .

When light is incident on the refraction members 40 and 41 under such a configuration, light is separated at an inclined angle in the vertical direction,

Light is prevented from entering into the separation space t ₁ on the boundary where the incident surface of the first unit prism 23 and the incident surface of the third unit prism 25 are bonded.

In detail, the light separated from the connection portion is changed in direction from the exit surface of the refracting members 40 and 41 to maintain parallelism in a separated state, where the interval t ₃ can be maintained, and the interval t ₃ Is larger than t ₁ , which is the spacing space, so that the light energy loss due to the spacing space can be prevented.

Here, even if t ₂ occurs, it can be realized as several tens of 탆, so that the loss of light is not realistic.

Those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Therefore, it is to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

23: first unit prism 24: second unit prism
25: third unit prism 26, 27: reflective member
28, 31: Half-wave retarder 29, 30, 32: Modulator
34: first optical splitter 35: second optical splitter
36: substrate 40:

Claims (10)

A light splitter that transmits incident light in one direction according to a polarization component and reflects the incident light in at least two different directions;
A reflecting member for reflecting the light reflected by the light splitter in a screen direction;
A plurality of unit prisms arranged around and bonded to each other around the optical splitter so that light transmitted through the optical splitter and light transmitted through or reflected by the optical splitter can pass therethrough;
And a substrate for guiding incident light to the plurality of unit prisms in order to prevent a light energy loss due to a tolerance occurring when arranging the plurality of unit prisms around the light splitter. The method according to claim 1,
Wherein:
Wherein the plurality of unit prisms are configured to cover a boundary portion to which the plurality of unit prisms are bonded. The method according to claim 1,
Wherein:
And the incident light is arranged on an incident surface to the plurality of unit prisms. The method according to claim 1,
Wherein the refractive index of the substrate and the refractive indices of the plurality of unit prisms are similar or have the same refractive index,
Wherein the stereoscopic image apparatus comprises:
Further comprising an adhesive layer for adhering the substrate to the plurality of unit prisms. The method according to claim 1,
Wherein the plurality of unit prisms include:
A first and a third unit prisms through which the light to be incident on the light splitter and the light reflected by the light splitter pass; / RTI >
The first and third unit prisms are connected to the first and third unit prisms so that the first and third unit prisms function as a flat plate and can be refracted with respect to light emitted from the first and third unit prisms. Wherein the angle formed between the incident plane of the first unit and the third unit prism and the exit plane of the light reflected by the optical splitter has the same value. The method according to claim 1,
Wherein the plurality of unit prisms include:
A first and a third unit prisms through which the light to be incident on the light splitter and the light reflected by the light splitter pass; / RTI >
The angle between the incident surface of the first and third unit prisms and the outgoing light is at least 0.1 degree or more so that the light emitted from the first and third unit prisms does not interfere with the incident surface of the first and third unit prisms And the three-dimensional image is displayed. The method of claim 1, wherein
Further comprising a refraction member disposed in front of the substrate and refracting light incident on the substrate to prevent light from being incident on a boundary portion where the plurality of unit prisms are joined. 8. The method of claim 7,
Wherein the refraction member includes a first refraction member and a second refraction member connected at a predetermined angle to the first refraction member, wherein a connecting portion of the first refraction member and the second refraction member is disposed in front of the boundary portion,
Wherein an arrangement angle between an incident surface of the first refraction member and an incident surface of the second refraction member is smaller than 180 degrees. The method according to claim 1,
Further comprising a lens through which the light passing through the plurality of unit prisms passes to pass through the light splitter so that the light reflected by the light splitter and the transmitted light have the same size. The method according to claim 1,
Further comprising at least one reflecting member-prism assembly including a prism and a reflecting member formed on one surface of the prism so that the light reflected by the beam splitter and the transmitted light have the same size, .

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