TWI670560B - Projector - Google Patents

Abstract

A projector includes a light source, a light leveling element, a light valve, a first optical element, and a second optical element that is permeable to light. The light source can output an illumination beam, and the light homogenizing element, the light valve, the first optical element, and the second optical element are disposed on a traveling path of the illumination beam. The first optical element and the second optical element are disposed between the light valve and the light homogenizing element. The second optical element is disposed on a surface of the first optical element and has a refracting power, the second optical element is provided with a curved surface, and an area of the curved surface of the second optical element is smaller than an area of the illumination light beam at the position of the second optical element.

Description

Projector

The present invention relates to a projector, and the present invention relates to a projector having better picture uniformity.

The projected image of the projector often has poor brightness uniformity, such as a brighter central area and a darker surrounding. As shown in FIG. 1 , when a plurality of projectors are used to splicing a TV wall screen 100, if the brightness uniformity is not good, the problem of discontinuity at the seam will be highlighted, and the overall quality and visual effect of the stitched picture will be reduced.

According to one aspect of the present invention, a projector is provided comprising a light source, a light leveling element, a light valve, a first optical element, and a second optical element that is permeable to light. The light source can output an illumination beam, and the light homogenizing element, the light valve, the first optical element, and the second optical element are disposed on a traveling path of the illumination beam. The first optical element and the second optical element are disposed between the light valve and the light homogenizing element. The second optical element is disposed on a surface of the first optical element and has a refracting power, the second optical element is provided with a curved surface, and an area of the curved surface of the second optical element is smaller than an area of the illumination light beam at the position of the second optical element.

According to another aspect of the present invention, a projector is provided comprising a light source, an integrator, a light valve, a first optical element, and a second optical element that is permeable to light. The light source can output an illumination beam, and the integrator, the light valve, the first optical element, and the second optical element are disposed on a path of travel of the illumination beam. The first optical element and the second optical element are disposed between the light valve and the integrator. The second optical element has a diopter and is provided with a curved surface, and the curved portion of the second optical element is completely covered by the illumination beam.

According to the above aspect of the present invention, by providing a refracting curved surface structure on the surface of the optical element or between different optical elements to provide a light diverging effect, the amount of light in a region where the brightness of the screen is high can be reduced to improve the overall brightness uniformity, for example, Improve the uneven brightness of the center of the projection screen with too high brightness and too dark edges. Furthermore, when a plurality of projectors are used to splicing a screen of a television wall, since the brightness of each projection screen is uniform, the spliced overall screen does not form a splicing line with a significant change in brightness, thereby improving picture quality and visual effects.

In order to make the invention more apparent, the following embodiments are described in detail with reference to the accompanying drawings.

1, 2‧‧‧ projector

10‧‧‧Light source

12‧‧‧Homogeneous components

12’‧‧‧ integrator

12a‧‧‧Glossy

14‧‧‧Optical components

16‧‧‧Optical components

18‧‧‧Support

20‧‧‧Optical components

22‧‧‧Optical components

20a‧‧‧Surface

30‧‧‧Light valve

100‧‧‧TV wall screen

C‧‧‧Central Block

I‧‧‧ illumination beam

L‧‧ lens

N‧‧‧ groove

P‧‧‧ surrounding blocks

TS‧‧‧Wings

MR‧‧‧ edge

FIG. 1 depicts a schematic diagram of a projected stitching picture.

2 is a schematic diagram showing the outline of a projector according to an embodiment of the present invention.

3 is a schematic diagram showing the outline of a projector according to another embodiment of the present invention.

4 is a schematic diagram showing the outline of a second optical component according to another embodiment of the present invention.

Figure 5 depicts a schematic overview of a second optical component in accordance with another embodiment of the present invention.

FIG. 6 is a schematic diagram showing a manner in which a screen brightness average value of a projector according to an embodiment of the present invention is taken.

The foregoing and other technical aspects, features and advantages of the present invention will be apparent from In addition, in the following examples The terms "first" and "second" are used to identify the same or similar elements, and the directional terms such as "front" and "back" are used only to refer to the direction of the additional drawing, and are not intended to be limiting. The element.

Please refer to FIG. 2. FIG. 2 is a schematic diagram of a projector according to an embodiment of the present invention. In the projector 1, the light source 10, the light homogenizing element 12, the optical element 16, the optical element 20, the optical element 22, and the light valve 30 provided on the traveling path of the illumination light beam I are sequentially included in accordance with the traveling path of the bright light beam. The optical element 16 is disposed between the light valve 30 and the light homogenizing element 12.

In this embodiment, the light source 10 can be an element that provides an illumination beam I, such as a conventional thermoelectric source, a fluorescent lamp, a light emitting diode, or a laser emitting diode. In this example, the light source 10 is a packaged white light emitting diode module with phosphor powder.

In the present invention, "homogeneous element" 12 refers to a lens array (LENS ARRAY), an integrator column (INTEGRATE ROD), a rotatable crucible, and other optical elements or optical modules that can be used to make the light uniform. In this example, the light homogenizing element 12 is a solid integrating column.

The term "optical element" as used in the present invention means that the element has a part or all of a material that can be reflected or penetrated, and usually consists of glass or plastic. For example, the optical element can be a lens, TIR Prism, RTIR Prism, various integrators, various filters, and the like. In this embodiment, optical element 16 is a lenticular lens having a positive diopter.

In this embodiment, optical element 20 is a lens that has a negative refracting power and is permeable to light. The optical element 20 is provided with a concave curved surface 20a having a refracting power, and the curved surface 20a is provided on the light-incident surface or the light-incident surface of the optical element 20. On the contrary, the backlight surface or the light-emitting surface of the curved surface 20a is an unbiased The physical plane of luminosity.

In this embodiment, the optical element 22 can be a field lens, a TIR PRISM T composed of a plurality of turns, or a reverse total internal reflection set including a single turn ( RTIR PRISM). In the present embodiment, the optical element 22 is a total internal reflection group formed by two full turns, and each of the light incident surface and the light exit surface of the optical element 22 are flat.

The term light valve 30 has been widely used in the projection industry and is used in the industry to refer to some of the individual optical units in a Spatial Light Modulator (SLM). A so-called spatial light modulator, comprising a plurality of independent units (independent optical units), which are spatially arranged in a one-dimensional or two-dimensional array. Each unit can independently control optical signals or electrical signals, and use various physical effects (Pockels effect, Kerr effect, acousto-optic effect, magneto-optic effect, self-electrooptic effect of semiconductor or photorefractive effect) to change itself. The optical characteristic is such that illumination of the illumination beam of the plurality of individual units is modulated and the image beam is output. The individual unit can be an optical component such as a micro mirror or a liquid crystal cell. That is, the light valve may be a Digital Micro-mirror Device (DMD), a liquid-crystal-on-silicon panel (LCOS Panel), or a transmissive liquid crystal panel.

The projector is a device that projects an image onto a screen by optical projection. In the projector industry, the projector is generally classified into a cathode ray tube (Cathode Ray Tube) projection depending on the light valve 30 used internally. Liquid crystal display (LCD) projectors, Digital Light Projector (DLP), and Liquid Crystal on Silicon (LCOS) projectors that pass through the LCD panel when the projector is operating As a light valve, it is a penetrating projector, and a projector using a light valve such as LCOS or DLP is It is developed by the principle of light reflection, so it is called a reflective projector. In the present embodiment, the projector is a digital light projector, and the light valve 30 is a digital micromirror device (DMD).

In this embodiment, the illumination beam I is converted into an image beam by the light valve 30 and then output through the optical element 22, and when the optical element 20 is disposed outside the traveling path of the image beam, it does not affect the light pattern of the image beam. For better design. Optical element 20 can be disposed at a light incident surface of optical element 22 (e.g., total reflection 稜鏡). As shown in FIG. 2, the illumination beam I emitted by the light source 10 is homogenized via the homogenizing element 12, passes through the lens L, and enters the optical element 22 via the optical element 20 to be projected onto the light valve 30. Since the optical element 20 can be provided with a curved surface 20a having a refracting power, and the curved surface 20a can provide a light diverging effect, when the curved surface 20a is disposed at a position corresponding to a higher brightness region of the optical element 22, the amount of light in the picture area can be reduced. Improve overall brightness uniformity. For example, if there is a problem that the brightness of the center of the projection screen is high, the optical element 20 can be disposed at the center of the light-incident surface TS of the optical element 22 as shown in FIG. 2, and provides an effect of diverging the central region light, thereby incident on the light. The light at the center of the valve 30 is diverged to the edge region of the light valve 30, which improves the uneven brightness of the center of the projected picture and the brightness of the edge is too dark.

It should be noted that in various embodiments of the present invention, the arrangement of the optical element 20 is not limited. For example, the light-curing adhesive may be disposed on the light incident surface or the light-emitting surface of the lens L or the total internal reflection 稜鏡 22 by gluing. Alternatively, a groove N may be directly formed on the light-incident surface (left side of FIG. 5) or the light-emitting surface (right side of FIG. 5) of the lens L to form an optical element 20 having a light-diverging effect. The curved surface formed by the groove N may be an aspherical surface or a free-form surface, as shown in FIG. 5, which is an example thereof.

Furthermore, please refer to FIG. 4, which depicts a schematic view of another embodiment of the optical component 20 of the present invention. As shown in FIG. 4, in the embodiment, the optical element L is a lens, and the optical element 20 can be set. On the light-incident surface (left side of FIG. 4) or the light-emitting surface (right side of FIG. 4) of the lens L to diverge the light incident thereto, and the length of the curved surface 20a of the optical element 20 in the direction of the vertical optical axis may be smaller than the light passing through the lens L. Aperture. Alternatively, the vertical projection of the curved portion of the optical element 20 in a plane perpendicular to the optical axis may also be smaller than the vertical projection of the portion of the optical aperture of the optical element 16 in the plane described above, and completely by the optical component 16. The projection image of the curved portion is completely covered. In addition, referring again to FIG. 2, in the present embodiment, the curved portion of the optical element 20 is completely covered by the range of the illumination beam I, that is, the optical element 20 has no portion that is not illuminated by the illumination beam I. .

In another embodiment, the optical element 20 can be integrated, for example, on the surface of the crucible to form a total internal reflection 稜鏡T having a raised structure.

The optical element 20 mentioned in the various embodiments of the present invention only needs to have a curved surface that can diverge light, and its shape is not limited. The curved surface may be concave, convex, free surface or other curved surface type that can interfere or change the optical path without limitation. For example, when the light beam passes through the concave surface 20a as shown in FIG. 2, it can be directly diverged; and when the light beam passes through a convex surface, the convex surface can first converge the light beam to the focus and then diverge, and the divergent light then enters the total internal reflection. The 稜鏡 and the light valve also have the effect of diverging the light incident to the center of the light valve to the edge region of the light valve, that is, the optical element 20 can be a lenticular lens. Therefore, those skilled in the art can arrange the curved surface type of the divergent light in a selected position in the optical path according to actual needs and apply to the required environment without limitation. In addition, although only a single lens L is schematically illustrated in FIG. 2, those skilled in the art will understand that a plurality of lenses may be provided between the optical element 16 and the light valve 30.

3 is a schematic diagram of a projector according to another embodiment of the present invention. The projector 2 sequentially includes light disposed on the traveling path of the illumination beam I according to the traveling path of the bright beam. Source 10, integrator 12', optical element 14, optical element 16, optically transmissive optical element 20, optical element 22, and light valve 30. The integrator 12', the light valve 30, the optical element 16, and the optical element 20 are all disposed on the traveling path of the illumination beam I, and the optical element 16 and the optical element 20 are both disposed between the integrator 12' and the light valve 30.

In this embodiment, the light source 10 is a packaged white light emitting diode light emitting module with phosphor powder.

The term "integrator" 12' of the present invention, or an optical integrator, can be used to homogenize light. The integrator can be of two types, a lens array (LENS ARRAY) or an integral column (INTEGRATE ROD). The integral column light integrator can be a hollow or non-hollow rod or column integrator. The lens array integrator can be a fly-eye lens. In this example, the integrator 12' is a solid integrating column.

In this embodiment, optical element 16 is a lenticular lens having a positive diopter. The optical element 20 is a biconcave lens having a negative diopter. In this embodiment, the optical component 20 can be an independently disposed lens and can be supported by a support member 18 to be disposed on the optical path between the lens L and the total internal reflection 稜鏡T. The support member 18 around the optical element 20 can be, for example, a light-transmissive flat glass or a single or a plurality of light-transmissive support rods, and the optical element 20 and the support member 18 can be integrally formed (ONE PIECE FORMED) and have a curved surface in the middle. And next to the flat components. The optical element T is a total internal reflection group formed by two full turns, and each of the light incident surface and the light exit surface of the optical element T is a flat surface. A light valve is a digital micromirror element (DMD). The integrator 12' is an integrating column that includes a light exiting surface 12a.

In this embodiment, optical component 16 is a lens located in integrator 12' and light. Between the valves 30. Although only a single lens L is schematically illustrated in Fig. 3, those skilled in the art will appreciate that a plurality of lenses may be provided between the integrator 12' and the light valve 30. The optical element 20 can be disposed between the integrator 12' and the light valve 30. In this embodiment, the optical element 20 can be disposed between the lens L and the optical element 22 (eg, total internal reflection 稜鏡), and the optical element 20 At least one diopter curved surface 20a is provided. The optical element 20 can also be used to scatter light from the middle portion to the periphery to enhance the intensity of the surrounding light, thereby enhancing the uniformity of the projected picture. Furthermore, the optical element 14 disposed between the integrator 12' and the lens L in the present embodiment may be, for example, a turning mirror, which reduces the volume occupied by the projector 2 by bending the traveling path of the illumination beam I.

In one embodiment, the curved surface 20a of the optical element 20 can be completely covered by the illumination beam I. For example, as shown in FIGS. 2 and 3, the curved surface 20a falls completely into the homo-light element 12 (or the integrator 12'). The area defined by the outermost edge of the emitted light beam, that is, if the illumination beam I forms a projection area on the extending plane of the optical element 20 along the vertical optical axis direction, the edge MR of the projection area is as shown in FIG. The curved surface 20a will fall completely into the projected area, and the area of the curved surface 20a will be smaller than the area of the projected area of the illumination beam I at the position of the optical element 20.

In one embodiment, the length of the diopter curved surface 20a of the optical element 20 in the direction of the vertical optical axis may be smaller than the optical element in front of the optical path (for example, the lens L) or the optical element 22 behind the optical path (for example, total internal reflection 稜鏡). The clear aperture, or both, is smaller than the clear aperture of the optical element adjacent to the front and rear. The term "clear aperture" as used herein refers to the diameter of a portion of the lens or crucible surface that is formed to assist in producing optical properties. For example, a lens or a peripheral region is formed with a flange or other structure for positioning assembly, etc., which is located outside the optically effective diameter of the lens or cymbal. In addition, the optical element 20 is One side of the optical element 16 and the optical element 22 are adjacent to each other, and there are no other elements between them and a gap is provided.

FIG. 4 depicts other variations of optical component 20. As shown in FIG. 4, in the embodiment, the optical component 16 can be a lens, and the optical component 20 can be disposed on the light-incident surface (left side of FIG. 4) or the light-emitting surface (right side of FIG. 4) of the lens L to diverge into the lens. Light, and the length of the curved surface 20a of the optical element 20 in the direction of the vertical optical axis may be smaller than the clear aperture of the lens L. It should be noted that in various embodiments of the present invention, the manner in which the optical element 20 is disposed on the surface of the optical element 16 is not limited. For example, the photo-curing adhesive may be disposed on the lens L or the optical element 22 by gluing. In another embodiment, as shown in FIG. 5, a groove N may be directly formed on the light-incident surface (left side of FIG. 5) or the light-emitting surface (right side of FIG. 5) of the lens L to form an optical component having a light-diverging effect. 20. The curved surface formed by the groove N may be an aspherical surface or a free-form surface. In another embodiment, the optical element 20 can be integrated, for example, on the surface of the crucible to form an optical element 22 (total internal reflection 稜鏡) having a raised structure.

The optical element mentioned in the various embodiments of the present invention only needs to have a curved surface that can diverge light, and its shape is not limited. Moreover, the curved surface may be a concave surface, a convex surface, a free surface or other curved surface type that can interfere or change the optical path without limitation. For example, when the light beam passes through the concave surface 20a as shown in FIG. 2, it can be directly diverged; and when the light beam passes through a convex surface, the convex surface can first converge the light beam to the focus and then diverge, and the divergent light then enters the total internal reflection. The 稜鏡 and the light valve also have the effect of diverging the light incident into the center of the light valve to the edge of the light valve. Therefore, those skilled in the art can arrange the curved surface type of the divergent light in a selected position in the optical path according to actual needs and apply to the required environment without limitation.

The table below shows that the optical element 22 (eg total internal reflection 稜鏡) is fitted with or without an optical element. The bright average of the piece 20 is measured data.

The bright average ECU-8 in the table is defined as the peripheral brightness of the screen divided by the percentage of the central luminance, wherein the peripheral luminance is the luminance value of the block having the smallest luminance among the eight peripheral blocks P shown in FIG. 6, and the central luminance is defined. It is the brightness value of the most central block C shown in FIG. It can be clearly seen from the table that the bright average ECU-8 to which the second optical element is attached is greater than 95% (95.9%, 95.3%) and the picture brightness uniformity is significantly improved.

With the design of each of the above embodiments, by providing a diopter surface structure on the surface of the optical element or between different optical elements to provide a light diverging effect, the amount of light in a region with a higher brightness of the screen can be reduced to improve the overall brightness uniformity. For example, it is possible to improve the brightness unevenness in the center of the projection screen where the brightness is too high and the edge is too dark. Furthermore, when a plurality of projectors are used to splicing a screen of a television wall, since the brightness of each projection screen is uniform, the spliced overall screen does not form a splicing line with a significant change in brightness, thereby improving picture quality and visual effects.

Various details can be freely changed when the invention is applied. For example, in the foregoing example, it is mentioned that a small optical element is used to scatter the light of the middle portion of the illumination light to achieve uniform brightness of the center and edge of the picture. The aforementioned smaller optical components can be placed in different positions besides the light-incident surface of the crucible; and in addition to the negative-diopter lens, the diopter can be positive to allow the light to be re-established by the optical path. Divergence after focusing can also achieve similar work Yes, this is the case.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Claims (10)

a projector comprising: a light source for outputting an illumination beam; a homogenizing element disposed on a path of the illumination beam; a light valve disposed on a path of the illumination beam; a first optical component, Between the light valve and the light absorbing element, and located on the traveling path of the illumination beam; and a second optical component that is transparent to light, disposed between the light valve and the light absorbing element, and located at the a second optical element is disposed on a surface of the first optical element, the second optical element has a refracting power, the second optical element is provided with a curved surface, and the curved surface of the second optical element The area is smaller than the area of the illumination beam at the location of the second optical component. The projector of claim 1, wherein the homogenizing element is an integrator. a projector comprising: a light source for outputting an illumination beam; an integrator disposed on the path of the illumination beam; a light valve disposed on the path of the illumination beam; a first optical component, Between the light valve and the integrator, on the traveling path of the illumination beam; and a second optical element capable of transmitting light, disposed between the light valve and the integrator and located at a path of the illumination beam The second optical component has a refracting power, the second optical component is provided with a curved surface, and the curved surface of the second optical component is at the position of the illumination beam at the second optical component Within the illumination range, the curved surface of the second optical element is smaller than the illumination range. The projector of claim 3, wherein the second optical component is disposed on a surface of the first optical component. The projector of claim 4, wherein the first optical component is a cymbal or a lens. The projector of claim 1 or 3, wherein a light exiting surface of the second optical component is disposed upstream of the optical path of the first optical component. The projector of claim 3, wherein there is no other optical element between the second optical element and the first optical element, and a gap is provided. The projector of claim 7, wherein the first optical component is a lens. The projector of claim 1 or 3, wherein the second optical element has a positive diopter. The projector of claim 3, wherein the projector sequentially includes the integrator, the second optical component, the first optical component, and the light valve along a path of travel of the illumination beam; The integrator is an integrating column, the first optical element is a total internal reflection group, the second optical element is a lens having a negative refractive power; the light emitting surface of the second optical element is attached to the total internal reflection One of the 稜鏡 groups enters the light surface, and the total internal reflection 稜鏡 group includes two turns.