US-12625419-B2 - Projection apparatus

US12625419B2US 12625419 B2US12625419 B2US 12625419B2US-12625419-B2

Abstract

Provided is a projection apparatus including a light valve, a projection lens, and an illumination system including at least one light-source module, at least one focusing lens, and at least one diffusing element. The excitation beams pass through from the at least one light-source module to the focusing lens and the diffusing element sequentially to form an illumination beam. The maximum width of a first light spot formed by the excitation beams on a light-exit surface of the focusing lens is a first width. The maximum width of a second light spot formed on a light-exit surface of the diffusing element is a second width. The maximum width of a third light spot formed by the illumination beam on a light-incident surface of the light valve is a third width. The first width is greater than the second width, and the second width is greater than the third width.

Inventors

Chang-Hsuan Chen

Assignees

CORETRONIC CORPORATION

Dates

Publication Date: 20260512
Application Date: 20230221
Priority Date: 20220223

Claims (20)

1 . A projection apparatus, comprising: an illumination system, a beam-adjusting element, a light valve, and a projection lens, wherein the illumination system is configured to provide an illumination beam, the light valve is disposed on a transmission path of the illumination beam and the light valve is configured to convert the illumination beam into an image beam, and the projection lens is disposed on a transmission path of the image beam and is configured to project the image beam out of the projection apparatus; the illumination system comprises at least one light-source module, at least one focusing lens, and at least one diffusing element, wherein: the at least one light-source module is configured to emit a plurality of excitation beams; the at least one focusing lens and the at least one diffusing element are disposed on a transmission path of the plurality of excitation beams emitted from the at least one light-source module, the at least one diffusing element is disposed between the at least one focusing lens and a focal point of the at least one focusing lens, and the plurality of excitation beams sequentially pass through the at least one focusing lens and the at least one diffusing element to form the illumination beam, wherein the beam-adjusting element is disposed on a transmission path of the illumination beam transmitted from the at least one diffusing element, located between the at least one diffusing element and the light valve, and is configured to depolarize the illumination beam and/or eliminate a speckle of the illumination beam; and a maximum width of a first light spot formed by the plurality of excitation beams on a light-exit surface of the at least one focusing lens is a first width, a maximum width of a second light spot formed by the plurality of excitation beams on a light-exit surface of the at least one diffusing element is a second width, a maximum width of a third light spot formed by the illumination beam on a light-incident surface of the light valve is a third width, and a maximum width of a fourth light spot formed by the illumination beam on a light-exit surface of the beam-adjusting element is a fourth width, wherein the first width is greater than the second width, the second width is greater than the third width, the second width is greater than the fourth width, and the fourth width is greater than the third width.
2 . The projection apparatus according to claim 1 , wherein the at least one diffusing element is located behind ½ of a total beam transmission path, the total beam transmission path comprises a transmission path of the plurality of excitation beams emitted from the at least one light-source module to the at least one diffusing element and a transmission path of the illumination beam transmitted from the at least one diffusing element to the light valve.
3 . The projection apparatus according to claim 1 , wherein each of the plurality of excitation beams forms a first sub-light spot on the light-exit surface of the at least one focusing lens, a maximum width of the first sub-light spot is a first sub-width, each of the plurality of excitation beams forms a second sub-light spot on the light-exit surface of the at least one diffusing element, a maximum width of the second sub-light spot is a second sub-width, and each of illumination sub-beams formed correspondingly by each of the plurality of excitation beams passing through the at least one diffusing element forms a third sub-light spot on the light-incident surface of the light valve, a maximum width of the third sub-light spot is a third sub-width, wherein the first sub-width is greater than the second sub-width, and the second sub-width is smaller than the third sub-width.
4 . The projection apparatus according to claim 3 , wherein a range of the third sub-light spots covering the light valve is equal to or greater than 70% of an area of the light valve.
5 . The projection apparatus according to claim 1 , wherein the at least one diffusing element is an asymmetric diffusing element, and a light spot of the illumination beam passing through the at least one diffusing element has a long axis and a short axis.
6 . The projection apparatus according to claim 1 , wherein the at least one diffusing element comprises a plurality of lenses disposed in arrays, and each of the lenses has a long axis and a short axis.
7 . The projection apparatus according to claim 1 , wherein a long axis of the third light spot corresponds to a long side of the light valve, and a short axis of the third light spot corresponds to a short side of the light valve.
8 . The projection apparatus according to claim 1 , wherein the third light spot is quadrilateral, and an included angle between a diagonal line of the third light spot and a diagonal line of the light valve is 10 degrees or less.
9 . The projection apparatus according to claim 1 , wherein the at least one light-source module further comprises: at least one light-combining element, disposed on the transmission path of the plurality of excitation beams emitted from the at least one light-source module, and located between an excitation-light source of the at least one light-source module and the at least one focusing lens.
10 . The projection apparatus according to claim 1 , wherein the beam-adjusting element comprises at least one of a depolarizer and a de-speckle element.
11 . The projection apparatus according to claim 1 , wherein each of the plurality of excitation beams forms a first sub-light spot on the light-exit surface of the at least one focusing lens, a maximum width of the first sub-light spot is a first sub-width, and each of the plurality of excitation beams forms a second sub-light spot on the light-exit surface of the at least one diffusing element, a maximum width of the second sub-light spot is a second sub-width, each of illumination sub-beams formed correspondingly by each of the plurality of excitation beams passing through the at least one diffusing element forms a third sub-light spot on the light-incident surface of the light valve, a maximum width of the third sub-light spot is a third sub-width, each of the illumination sub-beams forms a fourth sub-light spot on the light-exit surface of the beam-adjusting element, a maximum width of the fourth sub-light spot is a fourth sub-width, wherein the first sub-width is greater than the second sub-width, the second sub-width is smaller than the fourth sub-width, and the fourth sub-width is smaller than the third sub-width.
12 . The projection apparatus according to claim 1 , wherein the beam-adjusting element is located behind ½ of a total beam transmission path, the total beam transmission path comprises a transmission path of the plurality of excitation beams emitted from the at least one light-source module to the at least one diffusing element and a transmission path of the illumination beam transmitted from the at least one diffusing element to the light valve.
13 . The projection apparatus according to claim 1 , wherein the illumination system further comprises: at least one first actuating element, connected to the at least one focusing lens, and configured to move a position of the at least one focusing lens, wherein a position and a size of the third light spot relative to the light-incident surface change with a movement of the at least one focusing lens.
14 . The projection apparatus according to claim 1 , wherein the illumination system further comprises: at least one driving element connected to the at least one diffusing element, wherein the at least one diffusing element has an optical axis passing through a center thereof, the at least one driving element is configured to drive the at least one diffusing element to rotate around the optical axis, and a position of the third light spot relative to the light-incident surface changes with a rotation of the at least one diffusing element.
15 . The projection apparatus according to claim 1 , wherein the illumination system further comprises: at least one second actuating element, connected to the at least one diffusing element, wherein the at least one diffusing element has an optical axis passing through a center thereof, the at least one second actuating element is configured to move a position of the at least one diffusing element along the optical axis, and a size of the third light spot expands as the at least one diffusing element moves toward the at least one focusing lens and decreases as the at least one diffusing element moves toward the light valve.
16 . The projection apparatus according to claim 1 , wherein the illumination system further comprises: a plurality of light-source devices comprising the at least one light-source modules, wherein a number of the at least one focusing lens is plural, a number of the at least one diffusing element is plural, and each of the light-source devices respectively corresponds to one of the at least one focusing lens and one of the at least one diffusing element.
17 . The projection apparatus according to claim 16 , wherein the illumination system further comprises: a light-combining lens, disposed on the transmission path of the illumination beam from the at least one diffusing element, and located between the at least one diffusing element and the light valve.
18 . The projection apparatus according to claim 1 , wherein the plurality of excitation beams passing through the at least one focusing lens comprise at least one light color.
19 . The projection apparatus according to claim 1 , wherein the illumination system further comprises: a reflector, disposed on the transmission path of the illumination beam transmitted from the at least one diffusing element, and located between the at least one diffusing element and the light valve, wherein a maximum width of a fifth light spot formed by the illumination beam on a light-incident surface of the reflector is a fifth width, wherein the second width is greater than the fifth width, and the fifth width is greater than the third width.
20 . The projection apparatus according to claim 19 , wherein each of the plurality of excitation beams forms a first sub-light spot on the light-exit surface of the at least one focusing lens, a maximum width of the first sub-light spot is a first sub-width, a maximum width of a second sub-light spot formed by each of the plurality of excitation beams on the light-exit surface of the at least one diffusing element is a second sub-width, each of illumination sub-beams formed correspondingly by each of the plurality of excitation beams passing through the at least one diffusing element forms a third sub-light spot on the light-incident surface of the light valve, a maximum width of the third sub-light spot is a third sub-width, and the illumination sub-beam forms a fifth sub-light spot on the light-incident surface of the reflector, and a maximum width of the fifth sub-light spot is a fifth sub-width, wherein the first sub-width is larger than the second sub-width, the second sub-width is smaller than the fifth sub-width, and the fifth sub-width is smaller than the third sub-width.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority benefits of China application serial no. 202210166172.0, filed on Feb. 23, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. BACKGROUND Technical Field The invention relates to an optical apparatus, particularly to a projection apparatus. Description of Related Art The main light source of projection apparatus (such as projectors) on the current market are light-emitting diodes (LEDs) or laser diodes (LDs). To form an image on a screen, such projection apparatus is disposed with, for example, light sources of three different colors like red, green, and blue that are combined to provide an illumination beam guided directly into a homogenizer. The illumination beam is then directed through an optical element to a light valve to form an image beam that passes through a lens to form an image on the screen. The pure laser projection apparatus takes on greater proportions in the market nowadays; meanwhile, there are also demands for high-brightness projection apparatus. In order for the projected image to have higher brightness, it is also an inevitable trend to add more laser light sources in the projection apparatus. However, it is not an easy task to design a light-combining element, as the light-combining structure is usually bulky and complicated. And the use of homogenizers and other optical elements tends to loss the light energy efficiency. In addition, the projection apparatus cannot be used to adjust the size and shape of a light spotlight spot at will, which limits the acceptance of the projection apparatus in the market. The information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in the Background section does not mean that one or more problems to be resolved by one or more embodiments of the invention was acknowledged by a person of ordinary skill in the art. SUMMARY The invention provides a projection apparatus with a simple optical path structure that uses fewer optical elements, such that the production cost of the projection apparatus is lower and the light energy efficiency is better. Other objects and advantages of the invention may be further understood from the technical features disclosed in the invention. In order to achieve one, part, or all of the above objectives or other objectives, an embodiment of the invention provides a projection apparatus, which includes an illumination system, a light valve, and a projection lens. The illumination system is configured to provide an illumination beam. The light valve is disposed on the transmission path of the illumination beam and the light valve is configured to convert the illumination beam into an image beam. The projection lens is disposed on the transmission path of the image beam and is configured to project the image beam out of the projection apparatus. The illumination system includes at least one light-source module, at least one focusing lens, and at least one diffusing element. The light-source module is configured to emit multiple excitation beams. The focusing lens and the diffusing element are disposed on the transmission path of the excitation beams emitted from the light-source module. The diffusing element is disposed between the focusing lens and the focal point of the focusing lens, and the excitation beams sequentially pass through the focusing lens and the diffusing element to form the illumination beam. The maximum width of a first light spot formed by the excitation beams on a light-exit surface of the focusing lens is a first width. The maximum width of a second light spot formed on a light-exit surface of the diffusing element is a second width. The maximum width of a third light spot formed by the illumination beam on a light-incident surface of the light valve is a third width. The first width is greater than the second width, and the second width is greater than the third width. In an embodiment of the invention, the diffusing element is located behind ½ of the total beam transmission path. The total beam transmission path includes the transmission path of the excitation beams emitted from the light-source module to the diffusing element and the transmission path of the illumination beam transmitted from the diffusing element to the light valve. In an embodiment of the invention, each of the excitation beams forms a first sub-light spot on the light-exit surface of the focusing lens. The maximum width of the first sub-light spot is a first sub-width. Each of excitation beams forms a second sub-light spot on the light-exit surface of the diffusing element. The maximum width of the second sub-light spot is