TWI669563B - Projection module - Google Patents

Abstract

A projection module includes an image source for providing an image beam, an optical path adjusting unit, and a reflecting unit. The image beam is transmitted from the image source to the projection surface via the optical path adjustment unit and the reflection unit. The image beam includes a plurality of sub-beams respectively emitted from different positions of the image source, and the sub-beams are transmitted from the image source to the projection surface in substantially the same optical path, and the optical path of the sub-beams transmitted in the optical path adjusting unit In one direction increments.

Description

Projection module

The present invention relates to an optical device, and more particularly to a projection module.

When the projection device projects a picture to the projection screen, the angle of the projection screen often directly affects the quality of the image presentation. For example, when the projection device emits a projection beam when projecting the image, when the angle between the normal vector of the projection screen and the optical axis of the projection beam is too large, the projected image is often distorted and deformed, and even defocusing may occur. phenomenon. The existing technology is to solve the above problems by using an eccentric lens group and a reflecting lens, but the eccentric lens and the reflecting lens also increase the volume, weight and cost of the projection device.

On the other hand, when the display device projects a screen to a vertical projection screen, a certain distance between the projection screen and the display device is required to make the projected image have good quality, but at the same time, the space requirement is also increased. Therefore, although the volume of the projection device is reduced, unnecessary time and space waste is often caused between the projection screen and the projection device.

The invention provides a projection module that can project a good quality picture.

The projection module of the embodiment of the invention comprises an image source adapted to provide an image beam, an optical path adjusting unit and a reflecting unit. The image beam is transmitted from the image source to the projection surface via the optical path adjusting unit and the reflecting unit. The image beam includes a plurality of sub-beams respectively emitted from different positions of the image source, and the sub-beams are transmitted from the image source to the projection surface in substantially the same optical path, and the optical path of the sub-beams transmitted in the optical path adjusting unit A first direction is incremented.

The projection module of the embodiment of the invention comprises an image source adapted to provide an image beam, an optical path adjusting unit and a reflecting unit. The image beam is transmitted from the image source to the projection surface via the optical path adjusting unit and the reflecting unit. The optical path adjusting unit and the reflecting unit are arranged along a thickness direction, and the projection module conforms to 1≦H2/H1<10, wherein H1 is the thickness of the image source in the thickness direction, and H2 is the optical path adjusting unit and the reflecting unit are projected. The total thickness of the module in the thickness direction.

In an embodiment of the invention, each of the sub-beams is divided into a front beam and a back beam. The front beam is transmitted from the image source to the optical path adjustment unit. The rear beam is emitted from the optical path adjustment unit and transmitted to the projection surface. The optical paths of these front-end beams are incremented in a first direction, and the optical paths of the latter beams are decreased in a second direction.

In an embodiment of the invention, the material of the optical path adjusting unit is a light transmissive medium, and the optical path adjusting unit comprises a first light incident surface, a first inner reflective surface and a first light emitting surface. The image beam enters the optical path adjusting unit from the first light incident surface and is totally reflected by the first light emitting surface to the first internal reflection surface. The first internal reflection surface reflects the image beam from the first light-emitting surface to the first light-emitting surface, so that the light beam from the first internal reflection surface passes through the first light-emitting surface.

In an embodiment of the invention, the optical path adjusting unit is a turn.

In an embodiment of the invention, the reflecting unit is a plane mirror, a curved mirror or a crucible.

In an embodiment of the invention, the projection module further includes at least one light emitting unit, a light combining unit, and a lens group, and the image source is a light valve. The illumination unit emits an illumination beam, and the illumination beam is transmitted to the light valve through the light combining unit. The light valve reflects the illumination beam into an image beam, and the image beam is transmitted to the optical path adjustment unit through the light combining unit and the lens group.

In an embodiment of the invention, the H2 is less than 20 cm.

Based on the above, an embodiment of the present invention provides a projection module including an optical path adjusting unit and a reflecting unit. The projection module can provide a good projection image without increasing the volume of the projection module.

The above described features and advantages of the invention will be apparent from the following description.

1A is a schematic diagram of a projection module in accordance with a first embodiment of the present invention.

In the following description of the embodiments of the present invention, in order to clearly illustrate and indicate the disclosure of the embodiments of the present invention, the size of the components and the distance between the components will be enlarged, and is not intended to limit the present invention. The size, location, and related features of the inventive components. Referring to FIG. 1 , in the first embodiment of the present invention, the projection module 100 includes an image source 110 adapted to provide an image beam L, an optical path adjusting unit 120 , and a reflection unit 130 . In detail, the image light beam L emitted by the image source 110 is, for example, a light beam that can directly project an image on a plane.

The image beam L is transmitted from the image source 110 to the optical path adjusting unit 120, and the image beam L is transmitted to the reflecting unit 130 via the optical path adjusting unit 120. The reflecting unit 130 reflects the image light beam L from the optical path adjusting unit 120 to a projection surface. 50. That is, the optical path adjusting unit 120 and the reflecting unit 130 of the present embodiment enable the image source 110 to project an image on the projection surface 50, and the image light beam L includes sub-beams L1 and L2 respectively emitted from different positions of the image source 110. L3, these sub-beams L1, L2, L3 are transmitted from the image source 110 to the projection surface 50 in substantially the same optical path, and the optical paths transmitted by the sub-beams L1, L2, L3 in the optical path adjusting unit 120 are along One direction is incremented. Specifically, in the present embodiment, the positions at which the sub-beams L1, L2, and L3 enter the optical path adjusting unit 120 are different from each other in the thickness direction d1, and the sub-beams L1, L2, and L3 enter these positions of the optical path adjusting unit 120. In the middle, the sub-beams L1, L2, and L3 passing through the position of the reflection unit 130 in the thickness direction d1 are longer in the optical path transmitted by the optical path adjusting unit 120. In other words, in the present embodiment, the increasing trend of the optical path described above is that the path length of the sub-beams L1, L2, and L3 transmitted in the optical path adjusting unit 120 is substantially along the thickness direction toward the side of the reflecting unit 130. D1 is incremented.

The above optical path refers to the product of the refractive index of the medium through which light is transmitted and the length of light transmitted in the medium. For example, a projection beam for generating a projection picture is from a light valve, and a plurality of sub-beams of the projection beam are each from different positions of the light valve, and when the sub-beams reach a projection cloth via optical paths of different lengths During the curtain, the image formed on the projection screen will be distorted and out of focus, and the quality will be degraded. Since the projection module 100 of the present embodiment can transmit each of the sub-beams L1, L2, and L3 in the image light beam L to the projection surface 50 by the optical path adjustment unit 120 and the reflection unit 130, the projection is performed. The module 100 can form a good image on the projection surface 50. That is to say, the projection module 100 of the present embodiment can project a good picture on the projection surface 50.

On the other hand, the optical path adjusting unit 120 and the reflecting unit 130 of the present embodiment are arranged along the thickness direction d1, and the projection module 100 conforms to 1≦H2/H1<10, wherein H1 is the image source 110 in the thickness d1 direction. The thickness, H2, is the total thickness of the optical path adjusting unit 120 and the reflecting unit 130 in the thickness direction d1 of the projection module 100.

Therefore, the projection module 100 of the present embodiment can project the image light beam L1 to the projection surface 50 by the optical path adjusting unit 120 and the reflection unit 130 without using, for example, a plurality of eccentric lenses or reflective lenses. This is achieved, thus greatly reducing the overall thickness of the projection module 100. That is, the projection module 100 of the present embodiment can also improve the thickness of the projection module 100 when providing a good projection screen to the projection surface 50. Further, the H2 of the embodiment can be less than 20 cm (millimeter, mm), so that the projection module 100 having a small size can be provided.

In other words, the projection module 100 of the present embodiment can project the entire image beam L provided by the image source 110 onto the projection surface 50 by using substantially the same optical path, that is, the image quality of the image beam L on the projection surface 50. It is not changed because the sub-beams of the image beam L are emitted from different positions of the image source 110, so that the projected picture is not distorted or out of focus.

In detail, the sub-beam L1 in the present embodiment is divided into a front beam L11 and a rear beam L12, and the sub-beam L2 is divided into a front beam L21 and a rear beam L22, and the sub-beam L3 is divided into a front beam L31 and a rear beam L32. The front-end light beams L11, L21, and L31 are transmitted from the image source 110 to the optical path adjusting unit 120 until leaving the optical path adjusting unit 120. The rear-end light beams L12, L22, and L32 are emitted from the optical path adjusting unit 120 and transmitted to the projection surface 50. That is, the above-mentioned light beams L1, L2, and L3 are divided into the front-end light beams L11, L21, and L31 and the rear-end light beams L12, L22, and L32 by the end portion of the optical path adjusting unit 120 for emitting light.

In the present embodiment, since the optical paths of the front-end light beams L11, L21, and L31 in the optical path adjusting unit 120 are different from each other, the optical paths of the front-end light beams L11, L21, and L31 are increased along the thickness direction d1, and these rear-end light beams are increased. The optical paths of L12, L22, and L32 are decreased along one direction d2. Therefore, the sub-beams L1, L2, L3 can be transmitted to the projection surface 50 with the same optical path. In other words, the projection module 100 of the present embodiment uses the optical path adjusting unit 120 to make the optical path increment sequence of the front beam of the sub-beam in the image beam L opposite to the optical path increment sequence of the subsequent beam, thereby compensating the rear beam. The difference in optical path between L12, L22, and L32 allows the projected image on the projection surface 50 to maintain good quality.

1B is a perspective view of a projection module in accordance with a first embodiment of the present invention. Referring to FIG. 1A and FIG. 1B together, in the embodiment, the projection module 100 further includes a light emitting unit 140, a light combining unit 150, and a lens group 160, and the image source 110 is, for example, a light valve. In detail, the lens group 160 is exemplarily illustrated in FIG. 1B to indicate its relative positional relationship with other components, and is not intended to limit the number thereof. The illumination unit 140 emits an illumination beam L0 to the light combining unit 150. The illumination beam L0 is transmitted to the light valve (the image source 110) via the light combining unit 150, and the light valve (the image source 110) reflects the illumination beam L0 into the image beam L. The image beam L is sequentially transmitted to the optical path adjusting unit 120 via the light combining unit 150 and the lens group 160, so that the projection module 100 can project a good image on the projection surface. Since the light-emitting unit 140 and the light-combining unit 150 of the present embodiment are disposed substantially in a direction perpendicular to the thickness direction d1, the projection module 100 as a whole can have a relatively low thickness, thereby providing a good thinning effect.

The light combining unit 150 is, for example, a Total Internal Reflection Prism (TIR Prism) that transmits the illumination light beam L0 to the image source 110 by total reflection. In other embodiments, the light combining unit may be a reverse total internal reflection Prism (RTIR Prism), a beam splitter, a polarizer beam splitter or a field lens. The design of the splitting or light guiding required by the projection module 100 is appropriately matched, and the present invention is not limited thereto.

In detail, the optical path adjusting unit 120 of the present embodiment is, for example, a light-transmitting medium, and the optical path adjusting unit 120 includes a first light-incident surface 121, a first internal light-reflecting surface 122, and A first light exit surface 123. The image light beam L enters the optical path adjusting unit 120 from the first light incident surface 121 and is totally reflected by the first light emitting surface 123 to the first internal reflection surface 122 . The first internal reflection surface 122 reflects the image light beam L from the first light-emitting surface 123 to the first light-emitting surface 123, and further causes the image light beam L from the first internal reflection surface 122 to pass through the first light-emitting surface 123. In this embodiment, the first light-incident surface 121, the first internal reflection surface 122, and the first light-emitting surface 123 surround the side surface of a triangular cylinder, for example, so that the sub-beams L1 and L2 of the image light beam L can be transmitted through the above-described transmission method. L3 is transmitted in the optical path adjusting unit 120 with different optical paths, thereby compensating for the optical path difference of the image light beam L in the subsequent transmission process.

In the present embodiment, the reflecting unit 130 is a mirror having a reflecting surface 131, and the reflecting surface 131 is a flat surface and is at an angle with the first light emitting surface 123, but the invention is not limited thereto.

2A is a schematic diagram of a projection module in accordance with a second embodiment of the present invention. It is to be noted that the following embodiments use the same reference numerals and parts of the above-mentioned embodiments, and the same reference numerals are used to refer to the same or similar elements, and the description of the same technical content is omitted. For the description of the omitted portions, reference may be made to the foregoing embodiments, and the following embodiments are not repeated. Referring to FIG. 2, the projection module 100A is substantially similar to the projection module 100, but the main difference is that in the embodiment, the reflection unit 130A is another crucible, and the reflection unit 130A includes a second input. The smooth surface 131A, a second internal reflection surface 132A, and a second light-emitting surface 133A. The second light incident surface 131A facing the first light emitting surface 123A is for receiving the image light beam LA from the first light emitting surface 123A, and the first light emitting surface 123A is parallel to the second light incident surface 131A. The second internal reflection surface 132A reflects the image light beam LA from the second light incident surface 131A to the second light exit surface 133A, and further causes the image light beam LA to pass through the second light exit surface 133A and be transmitted to the projection surface 50A.

2B is a perspective view of a projection module in accordance with a second embodiment of the present invention. On the other hand, the light combining unit 150A in the second embodiment of the present invention is a reverse total reflection 稜鏡, and the light beam emitted from the light emitting unit 140A passes through the light combining unit 150A and reaches the image source 110A, and the image source 110A reflects the light beam into an image. The light beam LA is then totally reflected by the light combining unit 150A and transmitted to the optical path adjusting unit 130A.

3 is a schematic diagram of a projection module in accordance with a third embodiment of the present invention. Referring to FIG. 3, the projection module 100B is substantially similar to the projection module 100, but the main difference is that in the embodiment, the reflective surface 131B of the reflective unit 130B is a reflective curved surface. The image beam from the image source is transmitted to the projection surface 50B via the optical path adjusting unit 120B and the reflecting surface 131B of the reflecting unit 130B to form a good projection screen.

In summary, the embodiment of the present invention provides a projection module including an optical path adjusting unit and a reflecting unit. When the image beam provided by the image source of the projection module is reflected by the reflecting unit to a projection surface, the optical path difference is obtained. The optical path adjusting unit can compensate for the optical path difference of the image beam, so that the optical path of the whole image beam transmitted from the image source to the projection surface is the same, and the image projected by the projection module can match the projection surfaces of various angles. . On the other hand, since the overall thickness of the optical path adjusting component and the reflecting unit of the present embodiment is close to the image source, the projection module of the embodiment can provide a good thinning function.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

D1, d2‧‧‧ direction

H1, H2‧‧‧ thickness

L, LA‧‧ ‧ image beam

L0‧‧‧ illumination beam

L1, L2, L3‧‧‧ sub-beams

L11, L21, L31‧‧‧ front beam

L12, L22, L32‧‧‧ rear beam

N‧‧‧ normal vector

50, 50A, 50B‧‧‧ projection surface

100, 100A, 100B‧‧‧ projection module

110, 110A‧‧‧ image source

120, 120A, 120B‧‧‧ optical path adjustment unit

121‧‧‧First entrance

122‧‧‧First internal reflection surface

123, 123A‧‧‧ first light surface

130, 130A, 130B‧‧‧reflection unit

131, 131B‧‧‧reflecting surface

131A‧‧‧Second entrance

132A‧‧‧Second internal reflection surface

133A‧‧‧second glazing

140, 140A‧‧‧Lighting unit

150, 150A‧‧ ‧ light unit

160‧‧‧ lens group

1A is a schematic diagram of a projection module in accordance with a first embodiment of the present invention. 1B is a perspective view of a projection module in accordance with a first embodiment of the present invention. 2A is a schematic diagram of a projection module in accordance with a second embodiment of the present invention. 2B is a perspective view of a projection module in accordance with a second embodiment of the present invention. 3 is a schematic diagram of a projection module in accordance with a third embodiment of the present invention.

Claims (8)

A projection module includes: an image source adapted to provide an image beam; an optical path adjusting unit; and a reflecting unit, the image beam is transmitted from the image source to the projection via the optical path adjusting unit and the reflecting unit The image beam includes a plurality of sub-beams respectively emitted from different positions of the image source, the sub-beams being transmitted from the image source to the projection surface by substantially the same optical path, and the sub-beams are The optical path transmitted in the optical path adjustment unit is incremented along a first direction. The projection module of claim 1, wherein each of the sub-beams is divided into a front beam and a rear beam, the front beam from the image source to the optical path adjusting unit, The rear beam is emitted from the optical path adjusting unit and transmitted to the projection surface, and the optical paths of the front beams are increased along the first direction, and the optical paths of the rear beams are decreased along a second direction. A projection module includes: an image source adapted to provide an image beam; an optical path adjusting unit; and a reflecting unit, the image beam is transmitted from the image source to the projection via the optical path adjusting unit and the reflecting unit The image beam includes a plurality of sub-beams respectively emitted from different positions of the image source, and the sub-beams are transmitted from the image source to the projection surface by substantially the same optical path, wherein the optical path adjusting unit And the reflecting unit is arranged along a thickness direction, and the projection module conforms to 1≦H2/H1<10, wherein H1 is the thickness of the image source in the thickness direction, and H2 is the optical path adjusting unit and the reflecting unit The total thickness in the thickness direction of the projection module. The projection module of any one of claims 1-3, wherein the material of the optical path adjusting unit is a light transmissive medium, and the optical path adjusting unit comprises: a first light incident surface; a first inner reflecting surface; and a first light emitting surface, wherein the image light beam enters the optical path adjusting unit from the first light incident surface and is totally reflected by the first light emitting surface to the first inner reflecting surface, the first The internal reflection surface reflects the image beam from the first light-emitting surface to the first light-emitting surface, and further causes a light beam from the first internal reflection surface to pass through the first light-emitting surface. The projection module according to any one of claims 1-3, wherein the optical path adjusting unit is one turn. The projection module of any one of claims 1-3, wherein the reflection unit is a plane mirror, a curved mirror or a dome. The projection module of any one of claims 1-3, further comprising at least one light emitting unit, a light combining unit and a lens group, wherein the image source is a light valve, and the light emitting unit emits a light emitting unit An illumination beam is transmitted to the light valve through the light combining unit, and the light valve converts the illumination beam into the image beam, and the image beam is transmitted to the optical path adjusting unit via the light combining unit and the lens group . The projection module of claim 3, wherein the H2 is less than 20 cm.