TWI408489B - Projection system and projection method - Google Patents

Abstract

The invention discloses a projection system including a first telescope lens, a second telescope lens, and a display module. A screen includes a first region and a second region. The first telescope lens has a first optical axis, the first optical axis passes through the first region, and the first telescope lens is used for receiving a first light from the first region; the second telescope lens has a second optical axis, the second optical axis passes through the second region, and the second telescope lens is used for receiving a second light from the second region; the display module is coupled to the first telescope lens and the second telescope lens, the display module displays a first image according to the first light, and displays a second image according to the second light.

Description

Projection system and projection method

The present invention relates to a projection system and a projection method, and more particularly to a projection system and a projection method that can correct a projection direction and help adjust a projection focal length.

Nowadays, 3C products are getting faster and faster, and there are technical changes every few years. Today's TVs are moving toward larger sizes and thinner, and the film is being improved toward high-resolution images and multi-channel stereos to meet the needs of modern entertainment. In general, projection technology is the easiest to achieve the requirement to play large-size images. For example, a cinema can use projection technology to present a large screen with two floors.

In the case of a general projector, the purpose is to present a presentation at home to watch a movie or a company meeting. Most of the problems encountered in the use of distorted projection images, otherwise known as trapezoid distortion or keystone distortion. The distorted projection picture and its causes will be outlined below.

Please refer to Figure 1A to Figure 1C. Figure 1A shows a prior art projection system 1 projecting an image onto the screen 4 in a first direction. Figure 1B shows a prior art projection system 2 projecting an image onto the screen 4 in a second direction. Figure 1C shows a prior art projection system 3 projecting an image onto the screen 4 in a third direction. It should be noted that in FIG. 1A to FIG. 1C, the left side is a side view, and the right side is a top view. The screen 4 defines a vertical direction (VD) and a horizontal direction (horizontal direction).

Therefore, the first direction is perpendicular to the screen 4 in the longitudinal direction and the lateral direction; the second direction is not perpendicular to the screen 4 in the longitudinal direction, and is perpendicular to the screen 4 in the lateral direction; the third direction is not perpendicular to the screen 4 in the lateral direction, and is perpendicular to the screen 4 in the longitudinal direction. . At the same time, please refer to Figure 2A to Figure 2C. Figure 2A shows the projection screen in Figure A. Figure 2B is a projection screen in Figure 1B. Figure 2C shows the projection picture in Figure 1C. 2A to 2C, the projection system 1 in FIG. 1A projects a non-distorted image; the projection system 2 in FIG. 1B projects a vertical trapezoidal distortion image; and the projection system 3 projection in FIG. An image of a horizontal trapezoidal distortion.

The method of correcting the above-mentioned distorted image is generally classified into optical correction and digital correction. Optical correction uses the movement of the lens to make the projection direction perpendicular to the screen as far as possible in the vertical VD and the horizontal HD. However, due to the design of the mechanism, the design of optical correction and the mechanism cost are high. It is generally used for high-end projectors and is mostly used for portraits. Projection (correcting vertical trapezoidal distortion). The digital correction system uses an algorithm to calculate the degree of image distortion and inversely calculates a non-distorted image. Although the digital correction can also be used for lateral projection (correcting horizontal trapezoidal distortion), the quality of the digitally corrected projected image will deteriorate. Therefore, there is no projection system that can correct the vertical and horizontal projection directions without affecting the image quality and the mechanism cost is low.

In addition, in the general projection focusing mode, when the projector first projects an image onto the screen, the user adjusts the focal length of the projection lens to focus the projected image on the screen by viewing the image on the remote screen. However, current projectors are moving toward high-resolution projection images and high projection brightness. Therefore, users cannot easily view the projected images on the screen, and thus cannot easily focus the images, for example, need another person to View the projected image in front of the screen to determine if the projected image is in focus. Or, the projector is far away from the screen, and the user located next to the projector cannot accurately focus the projected image on the screen. For example, the projected image is clear from a distance from the screen, but the projected image is viewed closer to the screen. It is vague.

Accordingly, the present invention provides a projection system and projection method for solving the above problems.

One aspect of the present invention is to provide a projection system having two telescope heads for correcting the projection direction and for assisting in adjusting the projection focal length.

According to a specific embodiment, the projection system of the present invention is used to project an image on a screen, and the screen includes a first area and a second area. The projection system comprises a first telescope head, a second telescope head, a display module and a projection module. The first telescope head has a first optical axis, the first optical axis passes through the first region, the first telescope head receives the first light from the first region; and the second telescope head has a parallel to the first optical axis a second optical axis, the second optical axis passes through the second region, the second telescope head is configured to receive the second light from the second region; the display module is coupled to the first telescope head and the second telephoto lens, and displays The module displays the first image according to the first light, and displays the second image according to the second light; the projection module is used to project the image, and has a third optical axis parallel to the second optical axis. Furthermore, the first telescope head and the second telescope head have the same focal length that can be adjusted synchronously.

Another aspect of the present invention is to provide a projection method comprising the following steps. First, the first telescope head and the second telescope head are respectively oriented substantially toward the first region and the second region such that the first optical axis passes through the first region and the second optical axis passes through the second region. Then, adjusting the focal length of the first telescope head (that is, the focal length of the second telescope head is also adjusted at the same time), so that the first image produces a first image change, and the first telescope head is focused according to the first image change. The first area. Finally, a rotation axis is defined to intersect the first optical axis perpendicularly, and the projection system is rotated relative to the rotation axis such that the second image produces a second image change while the second telescope head is focused on the second region according to the second image change.

According to the projection system and method of the present invention, if the projection system is located on a plane, and the arrangement direction of the first telescope head, the projection module and the second telescope head is parallel to the plane, the projection direction may be perpendicular to the plane parallel to the plane. direction. If the alignment direction is perpendicular to the plane, the projection direction is perpendicular to the direction perpendicular to the plane on the screen.

Thereby, the projection system and the projection method of the present invention perform projection direction correction using two telescope heads. With the institutional design, the projection system of the present invention can correct horizontal or vertical trapezoidal distortion. Since the present invention is optically correct, it does not affect the image quality of the projection, and the optical mechanism for designing the two telescope heads is relatively inexpensive compared to the prior art design of the movable lens.

Moreover, since the projection system of the present invention can magnify the projected image by the telescope head. According to the image displayed by the display module, the projection focal length of the projection module can be easily adjusted to focus the projected image on the screen.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

Referring to FIG. 3, FIG. 3 is a schematic diagram of a projection system 5 according to a first embodiment of the present invention. As shown in FIG. 3, the projection system 5 is used to project an image on the screen 6, and the screen 6 includes a first area 60 and a second area 62. The projection system 5 includes a first telescope head 50, a second telescope head 52, a display module 54, and a projection module 56.

Generally speaking, in order to view a distant scene, the light from a distant scene or image can be received through the telescope head, and after being internally refracted or reflected by the optical structure of the lens, the magnifying lens can be viewed from the eyepiece. Far view. In addition, the telescope head is composed of a plurality of lenses, so that an optical axis can be defined through the lens core of these lenses. The first telescope head 50 has a first optical axis 500 and the second telescope head 52 has a second optical axis 520 that is parallel to the first optical axis 500. The first optical axis 500 passes through the first region 60, and the first telescope head 50 is configured to receive the first light from the first region 60. The second optical axis 520 passes through the second region 62, and the second telescope head 52 is configured to receive the second light from the second region 62.

The display module 54 is coupled to the first telescope head 50 and the second telescope head 52. The display module 54 displays the first image 540 according to the first light, and displays the second image 542 according to the second light. As shown in FIG. 3, the image in the first area 60 is a dog, and the image displayed by the display module 54 is an enlarged image of a partial area in the first area 60, that is, the first image 540 is a dog. A magnified image of the mouth. Moreover, if the magnification of the telescope head is large enough, the image displayed by the display module 54 will only be a few pixels in the projected image. Since the enlarged image can help to view the details of the image, the effect of the subsequent adjustment of the focal length of the telescope head on the image can be observed by the magnified image, thereby enabling accurate adjustment.

In fact, the display module 54 can be an optical display such as an optical viewing window or an eyepiece. If the display module 54 is intended to be an electronic display such as a liquid crystal panel, the projection system 5 needs to include the first photosensitive element 51 and the second photosensitive element 53. The first photosensitive element 51 is coupled to the first telescope head 50 for converting the first light received by the first telescope head 50 into a first electronic signal. Similarly, the second photosensitive element 53 is coupled to the second telescope head 52 for converting the second light received by the second telescope head 52 into a second electronic signal. The display module 54 includes a controller and is electrically connected to the first photosensitive element 51 and the second photosensitive element 53. The controller can receive the first electronic signal and the second electronic signal, and then display the first image 540 and the second image 542 on the panel through the circuit of the display module 54.

The projection module 56 is configured to project the image and has a third optical axis 560 parallel to the second optical axis 520. As shown in FIG. 3, the projection module 56 projects the image onto the projection area 64 of the screen 6, and the projection area 64 includes a first area 60 and a second area 62. Therefore, the projection module 56 needs to be projected first and then corrected. However, the present invention is not limited thereto. The first area 60 and the second area 62 may be only two areas on the screen 6. After the correction, the projection module 56 projects the image, and the projected image is an undistorted image.

The flow of correcting the projection direction of the projection system of the present invention will be described in detail below.

Please refer to Figure 4 and Figure 5A to Figure 5C. 4 is a flow chart of a projection method in accordance with an embodiment of the present invention. FIG. 5A to FIG. 5C are schematic diagrams showing the projection system 5 of the present invention projected according to the steps of FIG. 4. It should be noted that in FIG. 5A to FIG. 5B, multiple line composition and single line composition are used to respectively indicate that the focus has not been focused (blurred display image) and the focus is completed (clear display image). The projection method of the present invention comprises the following steps.

First, as shown in FIG. 5A, step S10 is performed to respectively guide the first telescope head 50 and the second telescope head 52 toward the first region 60 and the second region 62 on the screen 6, so that the first optical axis 500 passes through. The first region 60 and the second optical axis 520 pass through the second region 62.

The first telescope head 50 and the second telescope head 52 have the same focal length that can be adjusted synchronously. Next, step S12 is performed to adjust the focal length so that the first image 540 generates a first image change; and the first telescope head 50 is focused on the first region 60 according to the first image change. It is additionally noted that the adjustment of the focal length is generally a manual adjustment, such as rotating the focus ring of the first telescope head 50 in the direction of the curve in FIG. Of course, the adjustment of the focal length can also be automatically adjusted, with the optical mechanism design and the autofocus algorithm can achieve auto focus, which can be easily achieved by those skilled in the art, and will not be described here.

Defining a rotation axis perpendicular to the first optical axis 500, that is, the rotation axis is perpendicular to the drawing surface, and in a preferred embodiment, the rotation axis is disposed on the first lens of the front lens group of the first telescope head 50 It intersects with the first optical axis 500 as shown in FIG. 5C. Finally, step S14 is performed to rotate the projection system 5 relative to the rotation axis (the rotation direction is shown in the direction of the curve of FIG. 5C), so that the second image 542 generates a second image change; and at the same time, according to the second image change, the second telescope head is 52 is focused on the second region 62. At this time, the initial position (shown by the dashed line) of the projection system 5 has been adjusted to be parallel to the position of the screen (shown by the solid line), that is, the image projected by the projection module 56 can be horizontally perpendicular to the screen 6. It should be added that after the correction, the projection system 5 can be projected on the screen 6 in the correct direction, but it has not been determined that the projected image can be focused on the screen 6. Therefore, it is also necessary to adjust the focal length of the projection module 56 without adjusting the focal length of the telescope head while viewing the image displayed by the display module 54. The focal length of the projection module 56 is adjusted according to the change of the display image, so that the projected image can be focused on the screen 6.

Furthermore, it should be noted that defining the axis of rotation perpendicular to the first optical axis 500 is only one embodiment of the present invention. Moreover, in another embodiment, the rotation axis of the projection system 5 may also be defined only perpendicular to the first optical axis 500, the second optical axis 520, and the third optical axis 560, and does not intersect the first optical axis 500. In this embodiment, when step S14 is executed, that is, when the projection system 5 is rotated relative to the rotation axis, the user may need to adjust the focus ring of the second telescope head 52 on a larger scale, that is, adjust the first telescope head 50 in conjunction with each other. The focus ring is such that the first image 540 and the second image 542 are focused on the first region 60 and the second region 62.

Referring to FIG. 6, FIG. 6 is a schematic diagram showing a projection system 7 according to a second embodiment of the present invention. The main difference between FIG. 6 and FIG. 3 is that the first telescope head 70, the projection module 76 and the second telescope head 72 are longitudinally arranged. That is, the projection system 7 is located on a plane, the rotation axis 502 in FIG. 3 is perpendicular to the plane, and the rotation axis 702 in FIG. 6 is parallel to the plane. Similarly, in accordance with the projection method of Figure 4, the longitudinal projection of projection system 7 can be perpendicular to screen 8, thereby overcoming the problem of vertical trapezoidal distortion. It should be noted that the present invention is not limited thereto, and the projection system may have four telescope heads, that is, a telescope head configuration having the projection system 5 of FIG. 3 and the projection system 7 of FIG. Furthermore, horizontal and vertical trapezoidal distortion can be corrected simultaneously.

In addition, the projection system of the present invention can easily focus the projected image on the screen in addition to correcting the projected image. In general, whether it is a Digital Micromirror Device (DMD) or a liquid crystal projector, the projected image is composed of pixels. Therefore, please refer to FIG. 1 , FIG. 7A and FIG. 7B. FIG. 7A is a schematic diagram showing the image before the unfocused image displayed by the module 54 in FIG. FIG. 7B is a schematic diagram showing the image after focusing displayed on the display module 54 in FIG. It should be noted that since the magnification of the telescope head is large enough, the images shown in Figures 7A and 7B are composed of only a few pixels. According to the changes of FIG. 7A to FIG. 7B, the user can easily recognize whether the projected image is focused on the screen. For example, the image on the first area 60 of FIG. 1 is a dog, and FIG. 7A shows four square pixels, so that compared to the projected image, the display image has only a few pixels and only a few pixels. More complex projection images are easier to identify. Thereby, the image change caused by adjusting the focal length of the projection lens can be easily viewed, thereby focusing the projected image on the screen.

Compared with the prior art, the projection system and the projection method of the present invention utilize two telescope heads for projection direction correction and projection image focusing. With the institutional design, the projection system of the present invention can correct horizontal or vertical trapezoidal distortion. Since the present invention is an optical correction method, it does not affect the image quality of the projection, and the mechanism and design cost of setting the two telescope heads is relatively low compared to the design of the movable lens of the prior art. Moreover, the projection system of the present invention can zoom in and view the projected image by the telescope head, and according to the image displayed by the display module, the projection focal length can be easily adjusted to focus the projected image on the screen.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed. Therefore, the scope of the patented scope of the invention should be construed as broadly construed in the

1, 2, 3, 5, 7. . . Projection system

4, 6, 8. . . screen

50, 70. . . First telescope head

51. . . First photosensitive element

52, 72. . . Second telescope head

53. . . Second photosensitive element

54. . . Display module

56, 76. . . Projection module

60. . . First area

62. . . Second area

64. . . Projection area

500. . . First optical axis

502, 702. . . Rotary axis

520. . . Second optical axis

540. . . First image

542. . . Second image

560. . . Third optical axis

S10~S14. . . step

VD. . . Portrait

HD. . . Landscape

Figure 1A illustrates a prior art projection system projecting an image onto a screen in a first direction.

Figure 1B shows a prior art projection system projecting an image onto the screen in a second direction.

Figure 1C shows a prior art projection system projecting an image onto the screen in a third direction.

Figure 2A shows the projection screen in Figure A.

Figure 2B is a projection screen in Figure 1B.

Figure 2C shows the projection picture in Figure 1C.

Figure 3 is a schematic illustration of a projection system in accordance with a first embodiment of the present invention.

4 is a flow chart of a projection method in accordance with an embodiment of the present invention.

FIG. 5A to FIG. 5C are schematic diagrams showing the projection system of the present invention projected according to the steps of FIG. 4.

Figure 6 is a schematic illustration of a projection system in accordance with a second embodiment of the present invention.

FIG. 7A is a schematic diagram showing the image before the unfocused image displayed in the display module of FIG.

FIG. 7B is a schematic diagram showing the image after focusing displayed on the display module in FIG.

5. . . Projection system

6. . . screen

50. . . First telescope head

51. . . First photosensitive element

52. . . Second telescope head

53. . . Second photosensitive element

54. . . Display module

56. . . Projection module

60. . . First area

62. . . Second area

64. . . Projection area

500. . . First optical axis

502. . . Rotary axis

520. . . Second optical axis

540. . . First image

542. . . Second image

560. . . Third optical axis

Claims (10)

A projection system for projecting an image on a screen, the screen comprising a first area and a second area, the projection system comprising: a first telescope head having a first optical axis, the first optical axis Passing through the first region, the first telescope head is configured to receive a first light from the first region; a second telescope head having a second optical axis parallel to the first optical axis, a second optical axis is passed through the second area, the second telescope head is configured to receive a second light from the second area; and a display module is coupled to the first telescope head and the second a telescope head, the display module displays a first image according to the first light, the display module displays a second image according to the second light, and a projection module for projecting the image, having a parallel to the first a third optical axis of the two optical axes; wherein a rotating axis is defined, the rotating axis is perpendicular to the first optical axis, the second optical axis, and the third optical axis, and the rotating axis is disposed on the first telescope head The first lens of the mirror group intersects the first optical axis, The first telescope head and the second telescope head have the same and can adjust one focal length synchronously, adjust the focal length, so that the first image generates a first image change, and according to the first image change, the first telescope Focusing on the first area, and then rotating the projection system relative to the rotation axis, so that the second image generates a second image change, and focusing the second telescope head on the second area according to the second image change . The projection system of claim 1, further comprising a photosensitive element coupled to the first telescope head for converting the first light received by the first telescope head into an electronic signal The display module is electrically connected to the photosensitive element, and the display module receives the electronic signal to display the first image. The projection system of claim 1, wherein the projection module projects the image on a projection area of the screen, the projection area including the first area and the second area. The projection system of claim 1, wherein the projection system is located on a plane that is perpendicular to the plane. The projection system of claim 1, wherein the projection system is located on a plane parallel to the plane. A projection method for a projection system to project an image on a screen, the screen comprising a first area and a second area, the projection system comprising a projection module, a first telescope head, a second telescope head and a display module, the first telescope head is configured to receive a first light from the first area, and the second telescope head is configured to receive a second light from the second area, the display mode The display unit is coupled to the first telescope head and the second telescope head, the display module displays a first image according to the first light, and the display module displays a second image according to the second light, the first telescope The head has a first optical axis, the second telescope head has a second optical axis, the first telescope head and the second telephoto lens have the same and can adjust one focal length synchronously, and the projection module is used to project the The image has a third optical axis, the first optical axis, the second optical axis, and the third optical axis are parallel to each other, and define a rotating axis and the first optical axis, the second optical axis, and the third The optical axis is vertical, and the rotating axis is disposed at the a first lens of the lens group intersects the first optical axis before a telescope head, the projection method comprising the steps of: (a) respectively directing the first telescope head and the second telescope head toward the first region and The second area is such that the first optical axis passes through the first area and the second optical axis passes through the second area; (b) the focal length is adjusted such that the first image produces a first image change while Focusing the first telescope head on the first region according to the first image change; and (c) rotating the projection system relative to the rotation axis such that the second image generates a first image The second image is changed, and the second telescope head is focused on the second region according to the second image change. The projection method of claim 6, wherein the projection module projects the image on a projection area of the screen, the projection area including the first area and the second area. The projection method of claim 6, wherein the projection system comprises a photosensitive element coupled to the first telescope head for converting the first light into an electronic signal, the display mode The group is electrically connected to the photosensitive element, and the display module receives the electronic signal to display the first image. The projection method of claim 6, wherein the projection system is located on a plane that is perpendicular to the plane. The projection method of claim 6, wherein the projection system is located on a plane parallel to the plane.