KR20140099648A - Projector - Google Patents

Abstract

A projector of the present invention includes: a light source part for emitting a light; a synthesis system for synthesizing the light emitted from the light source part and an image according to an image signal; a projection lens for emitting the image synthesized in the synthesis part; and a housing for accommodating the light source part, the synthesis system and the projection lens. The synthesis system includes: an image panel for synthesizing the light incident from the light source part and the image signal; a prism which changes a direction of the light by transmitting the light incident on the synthesis system from the light source part and reflecting the light emitted from the image panel; and a cylinder lens which is interposed between the light source part and the prism and induces the light reflected from the reflection mirror to the image panel. The projector adjusts a ratio of the light incident on the image panel according to the characteristics of the image panel and can compensate aberration due to a different optical path generated as passing through a triangular prism.

Description

PROJECTOR {PROJECTOR}

The present invention relates to a projector that compensates for a light aberration of light reaching an image panel in a light source to provide a clear image.

The projector is used as an audiovisual video device that can directly connect a video device such as a computer or a camcorder and project it on a screen to perform various presentations or multimedia education.

The projector combines light emitted from a light source and an image according to an image signal, and the image is adjusted to a predetermined ratio and projected on a screen to be displayed outside. In a conventional projector, a projector in which a composite system for synthesizing a light source and a video signal, and a projection lens are flat in the same plane is generally used.

Projectors can use prisms that pass or reflect light according to the angle of incidence. However, due to the difference in refractive index between the prism and the air, the path of the light is slightly changed, resulting in optical aberration, and it is difficult to obtain a clear image.

An object of the present invention is to provide a projector with a sharp image quality by using a cylinder lens in order to solve the optical aberration caused by using a prism of a triangular prism.

The present invention relates to a light source which emits light; A synthesizer for synthesizing an image according to an image signal and light emitted from the light source; A projection lens for projecting an image synthesized in the capturing system; And a housing in which the light source unit, the composite system, and the projection lens are housed, wherein the composite system comprises: an image panel for synthesizing light incident from the light source unit with an image signal; A prism that transmits light incident on the synthesis system from the light source unit and reflects light emitted from the image panel to convert the direction of light; And a cylinder lens interposed between the light source and the prism for guiding light reflected from the reflector to the image panel.

The prism has a triangular prism shape having a triangular upper surface and a lower surface. The triangular prism has a first side where light is incident on the light source portion, a second side adjacent to an edge on one side of the first side and the prism has an image panel, And a third side surface adjacent to the other side edge of the first side surface and on which the projection lens is disposed, wherein the first side surface reflects light emitted from the image panel and can be emitted to the third side surface.

The radius of curvature in the horizontal direction of the cylinder lens may be larger than the radius of curvature in the vertical direction.

Wherein the cylinder lens has a thick portion of the cylinder lens passing through a thin portion of the cylinder lens so that light incident on one side edge of the first side surface passes through a thick portion of the cylinder lens and light incident on the other corner side passes through a thin portion of the cylinder lens, As shown in FIG.

The cylinder lens may be an asymmetric lens having a thick one end and a thin one.

One side of the cylinder lens adjacent to one side edge of the prism may be tilted toward the prism and the other side may be tilted toward the reflecting mirror.

The image panel may use a digital micromirror device (DMD) having a pixel mirror moving in units of pixels.

The light source may include three light sources for emitting red, green, and blue light, and a color synthesizing unit for synthesizing light emitted from the light source into white light.

And a light uniforming unit for uniformly supplying light emitted from the color combining unit.

The light uniformizing unit may include a fly-eye lens and a relay lens.

The relay lens may have a curvature radius in the horizontal direction smaller than a curvature radius in the vertical direction.

The relay lens collects light in a horizontal direction and diffuses light in a vertical direction.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

The projector of the present invention can adjust the ratio of light incident on the image panel to the characteristics of the image panel using a cylinder lens and compensate for the aberration caused by the light path difference caused by passing through the triangular prism.

The light incident on the prism is uniformly supplied to the digital micromirror device, thereby providing an accurate and clear image.

1 is a perspective view of a projector according to an embodiment of the present invention.
2 is a partial perspective view showing the internal components of the projector according to one embodiment of the present invention.
3 is a plan view of Fig.
FIG. 4 is a plan view showing a path of light in the synthesis system of FIG. 2. FIG.
FIG. 5 is a front view showing the path of light in the synthesis system of FIG. 2. FIG.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It should be understood, however, that there is no intention to limit the scope of the present invention to the embodiment shown, and other embodiments which are degenerative by adding, changing or deleting other elements or other embodiments falling within the spirit of the present invention Can be proposed.

1 is a perspective view showing a projector 100 according to an embodiment of the present invention and shows a housing 50 of the projector 100 and a projection lens 40 exposed on the front surface of the housing 50. As shown in Fig. The projector 100 of the present invention includes a projection lens 40 exposed to the outside and a light source unit 10, a composite system 30 and a projection lens 40 as shown in FIG. Light emitted from the light source unit 10 is combined with image information in the composite system 30, and is emitted through the projection lens 40, and an image is displayed on a screen or a wall surface.

FIG. 2 is a partial perspective view showing the internal parts of the projector according to the embodiment of the present invention, and FIG. 3 is a plan view thereof, showing the light source unit 10, the composite system 30 and the projection lens 40.

The light source unit 10 may include light sources 11, 12 and 13, a color synthesizing unit 14, and light uniformizing units 15 and 16.

The light source includes three lamps emitting light of red (11), green (12), and blue (13), and each lamp may be provided with a focusing lens for focusing light. The light emitted from the light sources 11, 12 and 13 is synthesized into white light by the color synthesizing unit 14 and the color synthesizing unit 14 synthesizes two intersecting dichroic mirrors Mirror) can be used.

The light synthesized by the white light is supplied to the light smoothing units 15 and 16. The light uniformizing portions 15 and 16 may include one or more fly eye lenses 15 and two fly eye lenses 15 may be arranged to face each other. The fly-eye lens 15 includes a plurality of fine lenses having a rectangular cross-sectional shape and is refracted when light passes through the fine lenses to intersect with light passing through adjacent fine lenses.

The light uniformizing units 15 and 16 may further include a relay lens 16 for focusing the light that has passed through the fly-eye lens 15. Light having passed through the light uniformizing units 15 and 16 is supplied to the synthesis system 30 through uniform rectangular light.

Since the radius of curvature of the relay lens 16 in the horizontal direction (y-axis direction) is smaller than the radius of curvature in the vertical direction (z-axis direction), the light incident on the relay lens 16 is collected in the horizontal direction, (See Figures 4 and 5). ≪ RTI ID = 0.0 >

 The light passing through the light uniformizing units 15 and 16 is provided to the synthesis system 30 and the synthesis system 30 includes an image panel 31 for synthesizing light and image information and emitting light in pixel units.

The image panel 31 composes a specific image by combining light and image information having information such as hue, saturation, brightness, etc. on a pixel-by-pixel basis. A digital micromirror device (DMD) can be used as the image panel 31.

The digital micromirror device 31 includes a plurality of micromirrors. The micromirror switches light thousands of times per second to selectively reflect light to synthesize light and image information.

The digital micromirror device 31 may be formed of a micromirror in the form of a rhombus, and has a rhomboid shape, so that the F number is different from the horizontal direction and the vertical direction. In the present invention, it is possible to use the digital micromirror device 31 in which the F number in the horizontal direction (y axis direction) is smaller than the F number in the vertical direction (z axis direction).

The smaller the F number, the brighter the light is, because it is brighter. The larger the F number, the darker it is. Therefore, light is supplied to the digital micromirror device 31 in a large area in the horizontal direction and refracted in the horizontal direction and the vertical direction by a cylinder lens relay lens so that light is supplied in a narrow area in the vertical direction .

Since the digital micromirror device 31 synthesizes image information and light in the form of reflecting light, light is again emitted in the incident direction. The light reflected from the reflecting mirror 20 is incident on the prism 32 so that the light reflected from the reflecting mirror 20 can be incident on the digital micromirror device 31 while transmitting the synthesized light from the digital micromirror device 31 in the direction of the projection lens 40 32).

The prism 32 has a triangular prism shape having three sides as shown in Fig. Light incident from the light source 10 is incident on the first side face 32a and the image panel 31 is positioned on the second side face 32b adjacent to the first side face 32a, A projection lens 40 is disposed on one side surface 32a and the third side surface 32c adjacent to the other side.

The first side surface 32a transmits light incident from the light source unit 10 and supplies the light to the image panel 31 located on the second side surface 32b. Light emitted from the image panel 31, And changes the light path in the direction of the third side surface 32c.

This selective transmission is caused by the refraction of light and the total reflection phenomenon. When light is incident on a medium having a large refractive index within a predetermined angle range, the property that light is totally reflected is referred to as total reflection. That is, the first side surface 32a reflects the light incident on the second side surface 32b toward the third side surface 32c using the total reflection property.

At this time, the angle between the second side surface 32b and the third side surface 32c may be 90 degrees, that is, a prism 32 of a right triangular prism may be used.

However, since the prism 32 has a triangular prism shape, the time for passing the prism 32 through the prism 32 varies depending on the position of the first side surface 32a of the prism 32, So that aberration occurs in the light incident on the image panel 31. When an aberration occurs, there is a problem that the brightness decreases, the light leakage occurs, and the resolution of the image decreases.

A cylinder lens 33 may be used to reduce the aberration caused by the optical path of the prism 32. The light transmitted through the prism 32 varies in accordance with the position at which the light is incident on the prism 32 and aberration occurs. Light having a short distance passing through the prism 32 passes through the cylinder lens 33 Light having a large distance and a long distance passing through the prism 32 can reduce the distance through which the cylinder lens 33 passes, thereby reducing the aberration.

4 and 5 show a path of light incident on the image panel 31 through the cylinder lens 33 and the prism 32. Fig. 4 is a plan view (xy) and Fig. 5 is a rear view (xz) . Referring to FIGS. 4 and 5, the arrangement of the cylinder lens 33 and the path through which light travels will be described in detail.

Light incident on one side of the light incident on the first side face 32a of the prism 32, that is, the portion A adjacent to the corner between the first side face 32a and the third side face 32c, ) Is short.

The cylinder lens 33 is arranged such that light passing through a thick portion of the cylinder lens 33 is incident on a first side A of the first side 32a of the prism 32. [

On the other hand, the light incident on the other portion B of the third side surface 32c of the prism 32, that is, the portion B adjacent to the edge between the first side surface 32a and the third side surface 32c, 32) is long.

The cylinder lens 33 is disposed such that light passing through a thin portion of the cylinder lens 33 is incident on the other side portion B of the first side surface 32a of the prism 32 in order to compensate for this.

That is, the thick portion 33 'of the cylinder lens 33 is disposed toward the A portion of the first side of the prism 32, and the thin portion 33' 'is disposed toward the B portion of the first side of the prism 32 do.

Accordingly, as shown in FIG. 4, the cylinder lens 33 of the present invention uses only a part of the lenses that are symmetrical in the left and right direction, and the size of the unused portion can be cut off. In the asymmetric cylinder lens 33, the cross section of one side portion 33 'is larger than the cross section of the other side portion 33 ".

Referring to the plan view of FIG. 4, the cylinder lens 33 is arranged obliquely such that one side portion 33 'is inclined toward the prism 32 and the other side portion 33' 'is inclined toward the light source.

Not only the distance through which the light passes through the cylinder lens 33 but also the angle of the light incident on the cylinder lens 33 from the light source and the angle incident on the prism 32 are also important factors for reducing the aberration. By tilting the cylinder lens 33 obliquely, the light path can be adjusted by adjusting the angle of the light incident on the cylinder lens 33.

The left and right sides of the cylinder lens 33 are formed to have an asymmetrical thickness in order to compensate for the difference in the distance through the prism 32 depending on the position of the light incident on the first side of the prism 32 of the present invention, The cylinder lens 33 is arranged obliquely to obtain a uniform and clear image without aberration by controlling the angle of incidence to the lens 32. [

The position of the cylinder lens 33 is affected not only by the prism 32 but also by the light incident from the relay lens 16. As shown in FIG. 4, the relay lens 16 of the light source unit 10 converges light in the x-axis direction in the y-axis direction and converges the light in the y-axis direction in the z- . Since the radius of curvature of the relay lens 16 in the horizontal direction is smaller than the radius of curvature in the vertical direction, light is more converged in the horizontal direction than in the vertical direction.

In order to narrowly supply light bent in the y-axis and the z-axis passing through the relay lens 16 to the image panel 31 in the horizontal direction (y-axis direction) and vertically (z-axis direction) The cylinder lens 33 refracts incident light in the horizontal direction (y-axis direction) while refracting it in the vertical direction (z-axis direction).

The cylinder lens 33 has a radius of curvature in the y-axis direction and a radius of curvature in the z-axis direction in order to make the degrees of refraction in the horizontal direction and the vertical direction different. The larger the radius of curvature is, the more gentle the light is not refracted. The radius of curvature in the horizontal direction is larger than the radius of curvature in the vertical direction.

As described above, in the projector according to the present invention, the light incident on the image panel using the cylinder lens is adjusted in proportion to the characteristics of the image panel, and the light path difference caused by passing through the triangular prism 32 Can be compensated for.

The light incident on the prism is uniformly supplied to the digital micromirror device, thereby providing an accurate and clear image.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

10: light source 11, 12, 13: lamp
14: color synthesizer 15: fly-eye lens
16: Relay lens
30: composite system 31: image panel
32: prism 33: cylinder lens
40: projection lens 50: housing

Claims (12)

A light source for emitting light;
A synthesizer for synthesizing an image according to an image signal and light emitted from the light source;
A projection lens for projecting an image synthesized in the capturing system; And
A housing in which the light source unit, the composite system, and the projection lens are housed,
The synthesis system
An image panel for combining the light incident from the light source unit with an image signal;
A prism that transmits light incident on the synthesis system from the light source unit and reflects light emitted from the image panel to convert the direction of light; And
And a cylinder lens interposed between the light source unit and the prism and guiding light reflected from the reflector to the image panel. The method according to claim 1,
The prism has a triangular prism shape having a triangular upper surface and a lower triangular prism,
A first side in which light is incident on the light source,
A prism having an edge on one side of the first side and a second side on which the image panel is disposed,
And a third side adjacent to the other edge of the first side and on which the projection lens is disposed,
Wherein the first side reflects light emitted from the image panel and emits light to the third side. 3. The method of claim 2,
The cylinder lens
Wherein the curvature radius in the horizontal direction is larger than the curvature radius in the vertical direction. 3. The method of claim 2,
The cylinder lens
Light incident on one side edge of the first side passes through a thick portion of the cylinder lens
The light incident on the other corner side passes through the thin portion of the cylinder lens
Wherein a thick portion of the cylinder lens is disposed to be biased in one direction. 5. The method of claim 4,
The cylinder lens
Wherein the lens is an asymmetrical lens having a thick one end and a thinner other end. The method according to claim 1,
The cylinder lens
Wherein one side of the prism adjacent to one side of the prism is inclined toward the prism and the other side of the prism is inclined toward the reflecting mirror. The method according to claim 1,
Wherein the image panel is a digital micromirror device (DMD) having a pixel mirror that moves pixel by pixel. The method according to claim 1,
The light source includes:
Three light sources for emitting red, green, and blue light,
And a color synthesizing section for synthesizing light emitted from the light source into white light. 9. The method of claim 8,
And a light uniforming unit for uniformly supplying light emitted from the color combining unit. 10. The method of claim 9,
Wherein the light uniformizing section includes a fly-eye lens and a relay lens. 11. The method of claim 10,
Wherein the relay lens has a curvature radius in a horizontal direction smaller than a curvature radius in a vertical direction. 11. The method of claim 10,
Wherein the relay lens collects light in a horizontal direction and diffuses light in a vertical direction.

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