Interactive rear projection system

Abstract

The present application provides an interactive rear projection system, which comprises a projection screen, a projection light machine, an input device and a controller. The projection light machine is used to emit a projection light beam, so that the projection light beam is projected on the projection screen. The input device comprises a sensor and a first light source. The sensor and the first light source are both arranged on a first side of the projection screen. The controller is electrically connected to the projection light machine, the sensor and the first light source. The controller controls the first light source to project a first light beam towards the projection screen. When an object approaches a second side of the projection screen, the sensor senses a light spot generated by the object diffusing the first light beam, and identifies the position of the object or the position of the object touching on the projection screen according to the light spot. The interactive rear projection system of the present application can realize simple and intuitive interactive effect.

Description

TECHNICAL FIELD

[0001] The present invention relates to a rear projection system, and more particularly to an interactive rear projection system. BACKGROUND

[0002] A rear projection system has an optical engine to project an image light beam to a mirror, and the image light beam is reflected by the mirror to an external projection screen connected to the rear projection system for displaying information.

[0003] However, the prior art design can only display information in one direction for a user to read. When the user wants to input information, the user can use a voice query method. However, if the query result has multiple choices provided to the user, the user can not intuitively select the desired item.

[0004] Another design is to add a touch module to the projection screen of the rear projection system. However, the cost of the touch module will increase a lot if the size of the projection screen is increased.

[0005] The background section of this document is included in to help understand the content of the present invention. Therefore, the content disclosed in the background section can include some content that is not prior art known to those of ordinary skill in the art. The content disclosed in the background section does not mean that the content or problems solved by one or more embodiments of the present invention were known or recognized by those of ordinary skill in the art before the filing date of this application. SUMMARY

[0006] The present invention provides an interactive rear projection system that can provide good interaction to a user simply and intuitively at a low cost.

[0007] Other objects and advantages of the present invention can be further understood from the technical features disclosed by the present invention.

[0008] To achieve one or some or all of the above-mentioned objects or other objects, an embodiment of the present invention provides an interactive rear projection system, which includes a projection screen, a projection optical engine, an input device, and a controller. The projection optical engine is used to emit a projection light beam, so that the projection light beam is projected on the projection screen. The input device includes a sensor and a first light source. The sensor and the first light source are both arranged on a first side of the projection screen. The controller is electrically connected to the projection optical engine, the sensor, and the first light source. The controller controls the first light source to project a first light beam toward the projection screen. When an object approaches a second side of the projection screen, the sensor senses a light spot generated by the object diffusing the first light beam, and identifies the position of the object or the position of the object touching the projection screen according to the light spot.

[0009] Based on the above, in an embodiment of the present application, the interactive back projection system is designed such that when an object approaches the second side of the projection screen, the sensor senses a light spot generated by the object diffusing the first light beam, and identifies the position of the object or the position of the object touching the projection screen according to the light spot. The interactive back projection system can further update the projection light beam using the position of the object or the position of the object touching the projection screen to achieve the effect of user interaction with the projection system. Therefore, the interactive back projection system of an embodiment of the present application can simply and intuitively provide a good interactive effect to the user, and can achieve a low-cost effect without adding an additional touch module.

[0010] In order to make the above features and advantages of the present application more apparent, specific embodiments are described below in detail, and are illustrated in the accompanying drawings as follows. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a perspective view of an interactive back projection system according to an embodiment of the present application.

[0012] Figure 2 is a cross-sectional view of an interactive back projection system according to an embodiment of the present application. DETAILED DESCRIPTION

[0013] The foregoing and other technical contents, features and effects of the present application will be apparent from the following detailed description of a preferred embodiment, with reference to the accompanying drawings. The directional terms mentioned in the following embodiments (for example, up, down, left, right, front or back, etc.) are only with reference to the directions of the accompanying drawings. Therefore, the directional terms are used for explanation, not for limiting the present application.

[0014] Figure 1 is a perspective view of an interactive back projection system according to an embodiment of the present application. Figure 2 is a cross-sectional view of an interactive back projection system according to an embodiment of the present application. Please refer to Figure 1 and Figure 2An embodiment of the present application provides an interactive rear projection system 10, which comprises a projection screen 100, a projection light machine 200, an input device 300, and a controller 400. The projection light machine 200 is used to emit a projection light beam IB, so that the projection light beam IB is projected on the projection screen 100. The projection light beam IB can be a visible light beam. The position where the projection light machine 200 emits the projection light beam IB and the position of a user are respectively located at two sides of the projection screen 100. In the embodiment, the position where the projection light machine 200 emits the projection light beam IB is specifically located at a first side of the projection screen 100, and the position of the user is specifically located at a second side of the projection screen 100. After the projection light beam IB is projected on the projection screen 100, the user watches an image by means of light transmitted from the projection screen 100. In addition, the material of the projection screen 100 can be a polymer-dispersed liquid crystal (PDLC) display, and the light transmittance of the projection screen 100 is adjusted by means of the characteristics of the material. The material of the projection screen 100 in the present application is not limited to this.

[0015] In the embodiment, the input device 300 comprises a sensor 330 and a first light source 310. The sensor 330 can be an infrared light sensor. The first light source 310 can be an infrared light source, for example, an infrared light emitting diode or an infrared light laser diode, but the present application is not limited to this. The first light source 310 is used to emit a first light beam L1, wherein the first light beam L1 can be an infrared light.

[0016] In the embodiment, the interactive rear projection system 10 further comprises a housing 600. The projection light machine 200 and the controller 400 are arranged in the housing 600. The projection screen 100 is arranged on the housing 600. The sensor 330 and the first light source 310 are also arranged on the housing 600. In addition, the sensor 330 and the first light source 310 are both arranged at the first side of the projection screen 100. For example, the projection screen 100 is arranged at the front end of the housing 600, and the sensor 330 and the first light source 310 are arranged at the rear end of the housing 600. In order to better show that the first light source 310 projects the first light beam L1 on the projection screen 100, the first light source 310 is shown above the sensor 330 along the X-axis direction in the embodiment, but the present application is not limited to the positional relationship between the sensor 330 and the first light source 310. Figure 2

[0017] ​In this embodiment, the controller 400 is electrically connected to the projection optical engine 200, the sensor 330, and the first light source 310. The controller 400 controls the first light source 310 to project a first light beam L1 onto the projection screen 100, and the first light beam L1 penetrates the projection screen 100. When a user approaches the second side of the projection screen 100 with an object H, the sensor 330 senses the light spot generated by the diffuse reflection of the first light beam L1 by the object H, and identifies the position of the object H or the position of the object H touching the projection screen 100 based on the light spot. The object H can be any light-blocking object, such as the user's hand.

[0018] In this embodiment, the sensor 330 uses the light spot generated by the diffuse reflection of the first light beam L1 by the object H to determine the position of the object H in a two-dimensional direction parallel to the projection screen 100. This two-dimensional direction can be defined by any non-parallel direction on the projection screen 100, for example... Figure 2 The X and Y axes are defined. Furthermore, the controller 400 receives and generates an update signal S based on the position of the object H or the position of the object H on the projection screen 100. The projection optical engine 200 receives and updates the projection beam IB based on the update signal S, and then projects the updated projection beam IB onto the projection screen 100.

[0019] In one embodiment, the sensor 330 can use the position of the object H corresponding to the projection screen 100 as the input coordinates of the input interface. For example, the controller 400 controls the projection optical engine 200 to project a selection interface (not shown) onto the projection screen 100. The sensor 330 obtains an input coordinate based on the light spot generated by the diffuse reflection of the first light beam L1 by the object H. The controller 400 determines the option corresponding to the selection interface based on the input coordinate, and then generates an update signal S, causing the projection optical engine 200 to update the image projected on the projection screen 100.

[0020] In order to make the interactive rear projection system 10 of this embodiment of the invention have a better interactive effect, in this embodiment, the projection range of the first beam L1 on the extension plane of the projection screen 100 is greater than or equal to the size of the projection screen 100, so that the interactive rear projection system 10 can effectively sense the position of the object H in space.

[0021] In addition, the controller 400 described above can be, for example, a microcontroller unit (MCU), a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a programmable controller, a programmable logic device (PLD), or other similar devices or a combination of these devices, without limitation. Furthermore, in an embodiment, the functions of the controller 400 can be implemented as a plurality of source codes. The source codes can be stored in a memory and executed by the controller 400. Alternatively, in an embodiment, the functions of the controller 400 can be implemented as one or more circuits. The present disclosure is not limited to the manner of implementing the functions of the controller 400 by software or hardware.

[0022] In an embodiment, the input device 300 further includes a second light source 320. The second light source 320 is disposed on the housing 600, and the projection screen 100 is disposed between the sensor 330 and the first light source 310 and the second light source 320. That is, the second light source 320 is disposed on the other side of the projection screen 100 opposite the first light source 310. More specifically, the second light source 320 and the object H are both located on the second side of the projection screen 100. Also, the second light source 320 can be an infrared light source, such as an infrared light-emitting diode or an infrared laser diode, but the present disclosure is not limited thereto. The second light source 320 is configured to emit a second light beam L2, which can be infrared light.

[0023] Furthermore, in an embodiment, the second light source 320 is electrically connected to the controller 400. The controller 400 controls the second light source 320 to project the second light beam L2. When the object H approaches the second side of the projection screen 100, the sensor 330 senses a light spot generated by the object H diffusely reflecting the second light beam L2, and identifies the position of the object H in a direction perpendicular to the projection screen 100 according to the light spot generated by the object H diffusely reflecting the second light beam L2. The direction perpendicular to the projection screen 100 is, for example, the Z-axis direction in the coordinate system shown in FIG. 1. In this way, by the sensor 330 sensing the light spots generated by the object H diffusely reflecting the first light beam L1 and the second light beam L2, the function of identifying the position of the object H in three-dimensional directions parallel and perpendicular to the projection screen 100 can be achieved. Figure 2

[0024] ​In one embodiment, the second light beam L2 emitted by the second light source 320 is preferably designed as an infrared surface light beam. For example, the second light source 320 is embodied as a light bar with a length greater than or equal to the length of the projection screen 100 in the Y-axis direction. Moreover, the projection range of the second light beam L2 is not overlapped with the projection screen 100. That is, the second light beam L2 is not projected onto the projection screen 100 to avoid misjudgment of the sensor 330. In addition, in another embodiment, the projection range of the second light beam L2 is parallel to the projection screen 100. Specifically, as shown in FIG. 6B, in the projection range of the second light beam L2, the surface light beam close to the projection screen 100 is parallel to the projection screen 100. Figure 2

[0025] In another embodiment, the interactive rear projection system 10 further comprises a reflector 500. The reflector 500 is disposed in the housing 600 and on the transmission path of the projection light beam IB between the projection light engine 200 and the projection screen 100. For example, the projection light engine 200 is disposed at the front end of the housing 600, the reflector 500 is disposed at the rear end of the housing 600, and the projection screen 100 is disposed at the front end of the housing 600. The projection light beam IB emitted by the projection light engine 200 is first transmitted to the reflector 500, and the reflector 500 reflects the projection light beam IB to the projection screen 100.

[0026] In summary, in one embodiment of the present application, the interactive rear projection system comprises a projection screen, a projection light engine, an input device, and a controller. The controller controls the first light source to project the first light beam toward the projection screen. When an object approaches the second side of the projection screen, the sensor senses the light spot generated by the object diffusing the first light beam, and identifies the position of the object or the position of the object touching the projection screen according to the light spot. Therefore, the interactive rear projection system can use the position of the object or the position of the object touching the projection screen as the input coordinates of the input interface, and further updates the projection light beam to achieve the effect of user interaction with the projection system.

[0027] The above description is only the preferred embodiments of the present application, and the scope of the present application is not limited by the above description. Any simple equivalent changes and modifications made according to the claims and the description of the present application are still within the scope of the present application. In addition, any embodiment or claim of the present application does not necessarily achieve all the purposes or advantages or features disclosed in the present application. Furthermore, the abstract and title of the specification are only used to assist patent document search and do not limit the scope of the present application. In addition, the terms "first", "second", etc. mentioned in the specification or claims are only used to name elements or distinguish different embodiments or ranges, and are not used to limit the upper or lower limit of the number of elements.

[0028] List of reference signs​

[0029] 10: interactive back projection system

[0030] 100: projection screen

[0031] 200: projector

[0032] 300: input device

[0033] 310: first light source

[0034] 320: second light source

[0035] 330: sensor

[0036] 400: controller

[0037] 500: reflector

[0038] 600: housing

[0039] H: object

[0040] IB: projected light beam

[0041] L1: first light beam

[0042] L2: second light beam

[0043] S: update signal

Claims

1. An interactive rear projection system, characterized in that, The interactive rear projection system includes a projection screen, a projection optical engine, an input device, and a controller, wherein: The projection optical engine is used to emit a projection beam so that the projection beam is projected onto the projection screen; The input device includes a sensor and a first light source, both of which are disposed on a first side of the projection screen; and The controller is electrically connected to the projection optical engine, the sensor, and the first light source. The controller controls the first light source to project a first beam of light onto the projection screen, and the first beam of light penetrates the projection screen and is transmitted to a second side of the projection screen. The first side and the second side are opposite sides of the projection screen, respectively. When an object approaches the second side of the projection screen, the sensor located on the first side senses the light spot generated by the object on the second side through diffuse reflection of the first beam of light. The interactive rear projection system identifies the position of the object in a two-dimensional direction parallel to the projection screen based on the light spot.

2. The interactive rear projection system according to claim 1, characterized in that, The first beam is infrared light, and the sensor is an infrared light sensor.

3. The interactive rear projection system according to claim 1, characterized in that, The projection range of the first beam on the extended plane of the projection screen is greater than or equal to the size of the projection screen.

4. The interactive rear projection system according to claim 1, characterized in that, The input device further includes a second light source, which is disposed on the second side of the projection screen and electrically connected to the controller, wherein: The controller controls the second light source to project a second beam. When the object approaches the second side of the projection screen, the sensor senses the light spot generated by the object on the second side through diffuse reflection of the second beam. The interactive rear projection system identifies the position of the object in a direction perpendicular to the projection screen based on the light spot generated by the second beam.

5. The interactive rear projection system according to claim 4, characterized in that, The projection range of the second beam does not overlap with the projection screen.

6. The interactive rear projection system according to claim 4, characterized in that, The projection range of the second beam is parallel to the projection screen.

7. The interactive rear projection system according to claim 4, characterized in that, The second beam is an infrared surface beam.

8. The interactive rear projection system according to claim 1, characterized in that, The interactive rear projection system also includes a reflector disposed on the transmission path of the projection beam between the projection optical engine and the projection screen.

9. The interactive rear projection system according to claim 1, characterized in that, The controller generates an update signal based on the position of the object, and the projection optical engine receives and updates the projection beam based on the update signal.

10. The interactive rear projection system according to claim 1, characterized in that, The sensor and the first light source are disposed on the housing, and the input device further includes a second light source, wherein the projection screen is disposed between the sensor, the first light source, and the second light source.

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