Patent Application
20240007598
This application claims the priority benefit of China application serial no. 202210778477.7 filed on Jun. 30, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The invention relates to a display device, and more particularly, to a projection system and a control method thereof.
In the case of using a projection system, if people or animals enter the projection range of the projection system unintentionally, they may be irradiated by the image beam emitted by the projection system, thereby causing harm to the eyes.
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.
The invention provides a projection system and a control method thereof that may improve the use safety of the projection system.
Other objects and advantages of the invention may be further understood from the technical features disclosed in the invention.
To achieve one or part or all of the above objects or other objects, a projection system of the invention includes a projection module, a mmWave sensor, and a control circuit. The projection module is configured to project an image beam to a projection surface. The mmWave sensor is configured to sense an object entering a sensing range and obtain a sensing result. The control circuit is coupled to the projection module and the mmWave sensor, and the control circuit is configured to control the projection module to provide the image beam according to the sensing result of the mmWave sensor.
In an embodiment of the invention, the control circuit includes a logic circuit and a light source driving circuit. The logic circuit is coupled to the mmWave sensor, and the logic circuit is configured to output an enable control signal according to the sensing result of the mmWave sensor. The light source driving circuit is coupled to the logic circuit and the projection module, and the light source driving circuit is configured to drive the projection module to provide the image beam according to the enable control signal.
In an embodiment of the invention, the logic circuit includes a first AND gate and a second AND gate. The first AND gate includes a first input terminal and a first output terminal, the first input terminal is coupled to the mmWave sensor, and the first AND gate is configured to output a logic signal according to the sensing result of the mmWave sensor. The second AND gate includes a second input terminal and a second output terminal, the second input terminal is coupled to the first output terminal of the first AND gate, the second output terminal is coupled to the light source driving circuit, and the second AND gate is configured to output the enable control signal according to the logic signal.
In an embodiment of the invention, the second AND gate further includes a third input terminal, and the control circuit further includes a projection control circuit. The projection control circuit is coupled to the projection module and the third input terminal, the projection control circuit is configured to output a first control signal to the second AND gate according to a working state of the projection module, and the second AND gate outputs the enable control signal according to the logic signal from the first AND gate and the first control signal.
In an embodiment of the invention, the projection system further includes a distance sensor coupled to the control circuit, and the distance sensor is configured to sense a distance between the projection module and the projection surface. The control circuit outputs a distance signal to the mmWave sensor according to the distance, and the mmWave sensor adjusts the sensing range from a first sensing range to a second sensing range according to the distance signal.
In an embodiment of the invention, the mmWave sensor adjusts a transmission power from a first transmission power to a second transmission power according to the distance signal.
In an embodiment of the invention, the control circuit adjusts the sensing range of the mmWave sensor according to a sensing range adjustment command.
In an embodiment of the invention, the mmWave sensor has a state indication value, the control circuit is configured to determine whether a state of the mmWave sensor is abnormal according to the state indication value, and the control circuit controls the projection module to provide the image beam according to the state indication value and the sensing result of the mmWave sensor.
In an embodiment of the invention, when the state of the mmWave sensor is abnormal, or the sensing result of the mmWave sensor is that the object enters the sensing range, the control circuit controls the projection module to stop providing the image beam.
In an embodiment of the invention, the control circuit includes a processing circuit, a logic circuit, and a light source driving circuit. The processing circuit is coupled to the mmWave sensor, and the processing circuit is configured to output a second control signal according to the state indication value. The logic circuit is coupled to the mmWave sensor and the processing circuit, and the logic circuit is configured to output an enable control signal according to the sensing result of the mmWave sensor and the second control signal. The light source driving circuit is coupled to the logic circuit and the projection module, and the light source driving circuit is configured to drive the projection module to provide the image beam according to the enable control signal.
In an embodiment of the invention, the logic circuit includes a first AND gate and a second AND gate. The first AND gate includes a first input terminal, a fourth input terminal, and a first output terminal. The first input terminal is coupled to the mmWave sensor, the fourth input terminal is coupled to the processing circuit, and the first AND gate is configured to output a logic signal according to the sensing result of the mmWave sensor and the second control signal. The second AND gate includes a second input terminal and a second output terminal, the second input terminal is coupled to the first output terminal of the first AND gate, the second output terminal is coupled to the light source driving circuit, and the second AND gate is configured to output the enable control signal according to the logic signal.
In an embodiment of the invention, the mmWave sensor includes a register, and the register is configured to store the state indication value.
In an embodiment of the invention, the projection system further includes a casing, the mmWave sensor is disposed in the casing, and the casing does not have an opening corresponding to a position where the mmWave sensor is disposed.
The invention also provides a control method of a projection system. Whether an object enters a sensing range is sensed via a mmWave sensor, and a sensing result is obtained. A projection module is controlled to provide an image beam according to the sensing result of the mmWave sensor via a control circuit.
In an embodiment of the invention, the control circuit includes a logic circuit and a light source driving circuit. The control method of the projection system includes the following steps. An enable control signal is output according to the sensing result of the mmWave sensor via the logic circuit. The projection module is driven to provide the image beam according to the enable control signal via the light source driving circuit.
In an embodiment of the invention, the logic circuit includes a first AND gate and a second AND gate. The control method of the projection system includes the following steps. A logic signal is output according to the sensing result of the mmWave sensor via the first AND gate. The enable control signal is output according to the logic signal via the second AND gate.
In an embodiment of the invention, the control circuit further includes a projection control circuit. The control method of the projection system includes the following steps. A first control signal is output to the second gate AND gate according to a working state of the projection module via the projection control circuit. The enable control signal is output according to the logic signal from the first AND gate and the first control signal via the second AND gate.
In an embodiment of the invention, the control method of the projection system includes the following steps. A distance between the projection module and a projection surface is sensed via a distance sensor. A distance signal is output to the mmWave sensor according to the distance via the control circuit. The sensing range is adjusted from a first sensing range to a second sensing range according to the distance signal via the mmWave sensor.
In an embodiment of the invention, the control method of the projection system includes adjusting a transmission power from a first transmission power to a second transmission power according to the distance signal via the mmWave sensor.
In an embodiment of the invention, the control method of the projection system includes adjusting the sensing range of the mmWave sensor according to a sensing range adjustment command via the control circuit.
In an embodiment of the invention, the control method of the projection system includes the following steps. Whether a state of the mmWave sensor is abnormal is determined according to a state indication value of the mmWave sensor via the control circuit. The projection module is controlled to provide the image beam according to the state indication value and the sensing result of the mmWave sensor via the control circuit.
In an embodiment of the invention, the control method of the projection system includes controlling the projection module to stop providing the image beam via the control circuit when the state of the mmWave sensor is abnormal, or the sensing result of the mmWave sensor is that the object enters the sensing range.
In an embodiment of the invention, the control circuit includes a processing circuit, a logic circuit, and a light source driving circuit. The control method of the projection system includes the following steps. A second control signal is output according to the state indication value via the processing circuit. An enable control signal is output according to the sensing result of the mmWave sensor and the second control signal via the logic circuit. The projection module is driven to provide the image beam according to the enable control signal via the light source driving circuit.
In an embodiment of the invention, the logic circuit includes a first AND gate and a second AND gate. The control method of the projection system includes the following steps. A logic signal is output according to the sensing result of the mmWave sensor and the second control signal via the first AND gate. The enable control signal is output according to the logic signal via the second AND gate.
Based on the above, the control circuit of the invention may control the projection module to provide the image beam according to the sensing result of the mmWave sensor. When a person or an animal enters the sensing range of the mmWave sensor, the control circuit may control the projection module to stop providing the image beam, so as to prevent the image beam from causing damage to the eyes of humans or animals, thereby improving the use safety of the projection system.
Other objectives, features and advantages of the present invention will be further understood from the further technological features disclosed by the embodiments of the present invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
It is to be understood that other embodiment may be utilized and structural changes may be made without departing from the scope of the present invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings.
In the present embodiment, the mmWave sensor 104 may detect subtle distance changes, for example, may detect distance changes in which the chest of a person or an animal rises and falls due to breathing. Therefore, even if people or animals do not move significantly within the sensing range, they may still be detected by the mmWave sensor 104, so that the control circuit 106 turns off the light source of the projection module 102.
In addition, in some embodiments, the mmWave sensor 104 may have a state indication value indicating whether the mmWave sensor 104 is abnormal. The control circuit 106 may determine whether the state of the mmWave sensor 104 is abnormal according to the state indication value. The control circuit 106 may control the projection module 102 to provide the image beam according to the state indication value and the sensing result Si of the mmWave sensor 104. For example, when the state of the mmWave sensor 104 is abnormal, or the sensing result of the mmWave sensor 104 is that the object enters the sensing range, the control circuit 106 may control the projection module 102 to stop providing the image beam.
In detail, the implementation of the control circuit 106 may be as shown in
Specifically, when the state indication value indicates that the mmWave sensor 104 is abnormal, the processing circuit 308 may provide the control signal SC2 of a low voltage level to the first AND gate 302 according to the state indication value. Or, when the sensing result 51 of the mmWave sensor 104 is that an object enters the sensing range, the mmWave sensor 104 may provide a low voltage level signal to the first AND gate 302 according to the sensing result 51. Then, the first AND gate 302 outputs the logic signal SL1 of a low voltage level to the second AND gate 304 according to the sensing result 51 or the control signal SC2. The second AND gate 304 then outputs the enable control signal EN1 of a low voltage level to the light source driving circuit 204, so that the light source of the projection module 102 is turned off. Therefore, the projection module 102 may be prevented from providing an image beam when the mmWave sensor 104 is abnormal or an object enters the sensing range. In contrast, when the mmWave sensor 104 is not abnormal, the processing circuit 308 may provide the control signal SC2 of a high voltage level to the first AND gate 302 according to the state indication value. Moreover, when the sensing result 51 of the mmWave sensor 104 is that no object enters the sensing range, the mmWave sensor 104 may provide a high voltage level signal to the first AND gate 302 according to the sensing result 51. Then, the first AND gate 302 outputs the logic signal SL1 of a high voltage level to the second AND gate 304 according to the sensing result 51 and the control signal SC2.
Moreover, the control signal SC1 is generated according to the working state of the projection module 102. Further, the projection control circuit 306 is configured to control the projection module 102 to perform projection-related operations, such as controlling the operation of elements such as the light source and the light valve of the projection module 102, in order to make the projection module 102 provide the illumination beam and the image beam and the like at the correct timing. The projection control circuit 306 enables the light source driving circuit 204 to drive the light source of the projection module 102 to provide the illumination beam to the light valve at the proper time via the control signal SC1, so that the projection module 102 may provide the correct image beam. In other words, even if the logic signal SL1 is in the state of allowing the image beam to be provided (the logic signal SL1 of a high voltage level), the projection control circuit 306 still needs to determine that the control time sequence of the projection operation enters the time point at which the image beam may be provided, and provide the corresponding control signal SC1 (for example, the control signal SC1 of a high voltage level) to the second AND gate 304, so that the light source driving circuit 204 may drive the projection module 102 to provide the image beam according to the enable control signal EN1 of a high voltage level provided by the second AND gate 304. The image beam is prevented from being provided when the working state of the projection module 102 is abnormal. Since in the present embodiment, the light source of the projection module 102 is turned off via a hardware (the logic circuit 202 and the light source driving circuit 204), the sensing result of the sensor does not need to be determined via the software or program of the processing circuit 308 (e.g., a scaling control chip or a microcontroller). Therefore, when the projection system 3 of the present embodiment senses that the object enters the sensing range, the response time for turning off the light source is very short, and the light source may be turned off within 200 ms.
For example, as shown in
Since the sensing distance of the mmWave sensor 104 is positively correlated with the magnitude of the transmission power, the mmWave sensor 104 may include, for example, a comparison table between the sensing distance and the transmission power, and the mmWave sensor 104 may adjust the transmission power according to the distance signal SD1, so that the mmWave sensor 104 may adjust the sensing range according to the transmission power. In other embodiments, instead of adjusting the transmission power of the mmWave sensor 104 to adjust the sensing range, the mmWave sensor 104 may choose to ignore the sensing results 51 outside the predetermined sensing range. For example, the sensing distance between the projection module 102 and the projection surface F1 is 1 meter. Even if the sensing distance of the mmWave sensor 104 is greater than 1 meter, the mmWave sensor 104 may still exclude the sensing result 51 having a sensing distance greater than 1 meter via an internal algorithm. That is, the mmWave sensor 104 does not send the logic signal SL1 of a low voltage level to the first AND gate 302 according to the sensing result 51 having a sensing distance greater than 1 meter. This prevents the projection system 5 from unnecessarily stopping providing the image beam. With the setting of the distance sensor 402, the distance sensor 402 may detect the sensing distance between the projection module 102 and the projection surface F1 in real time, so that the mmWave sensor 104 may dynamically adjust the sensing range.
Returning to
Further, the projection system 2 may include the logic circuit 202 and the light source driving circuit 204, and the logic circuit 202 may have the first AND gate 302 and the second AND gate 304. The control method of the projection system may be shown in
In some embodiments, the projection system 4 may also include a distance sensor 402. The control method of the projection system is shown in
In some embodiments, as shown in
In addition, in some embodiments, as shown in
Based on the above, the control circuit 106 of the invention may control the projection module 102 to provide the image beam according to the sensing result Si of the mmWave sensor 104. When a person or an animal enters the sensing range of the mmWave sensor 104, the control circuit 106 may control the projection module 102 to stop providing the image beam, so as to prevent the image beam from causing damage to the eyes of humans or animals, thereby improving the use safety of the projection system.
The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. Moreover, these claims may refer to use “first”, “second”, etc. following with noun or element. Such terms should be understood as a nomenclature and should not be construed as giving the limitation on the number of the elements modified by such nomenclature unless specific number has been given. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210778477.7 | Jun 2022 | CN | national |
