CN102034456B - Display device and control method thereof, projection device and control method thereof - Google Patents

Abstract

The invention provides a display device and a control method thereof, and a projection device and a control method thereof. The display device comprises at least one sensor, a processing unit and a control unit. The sensor is used for detecting a human body. The processing unit is connected with the sensor and used for capturing and processing the signal from the sensor to obtain sensing data. The control unit is connected with the processing unit and used for analyzing and judging whether the human body enters or leaves the sensing range of the sensor according to the sensing data. When the control unit judges that the distance between the human body and the sensing range reaches or exceeds a first preset time, the display device is closed or is caused to enter a power-saving/sleep mode; in addition, when the control unit judges that the human body enters the sensing range and reaches or exceeds a second preset time, the display device is started.

Description

Display device and control method thereof, projection device and control method thereof

technical field

The present invention relates to a detection control technology, and in particular to an electronic device with a sensor and its control method, especially to a display device, a control method for controlling the display device, a projection device and A control method for controlling a projection device.

Background technique

At present, there are roughly two power-saving mechanisms for display devices. One is to analyze the intensity of ambient light or the characteristics of image content when the user is using it, so as to adjust the brightness of the display module of the entire display device, so as to achieve The purpose of saving power; and the other is that when the user is not in use, the timer inside the display device is counted, and when no operation or use is found after a period of time, the display device is automatically turned off or the display is turned off. The device enters sleep/power saving mode to save power.

In addition, some display devices will detect whether there is signal input from the image signal input source or whether the image content has been updated. When the display device finds that there is no signal input from the image signal input source, invalid signal input, or no update of the image content within a certain period of time, the display device will automatically turn off or enter the sleep/power saving mode to achieve power saving. Purpose.

However, although the power saving mechanism mentioned above is effective, it often encounters the following problems in use, such as:

1. Some users will read information through a display device (may be equipped with a computer or other electronic circuit device). When the user is reading and thinking, he may not perform any operations on the computer or other electronic circuit devices connected to the display device, so the screen may be fixed on that screen. Therefore, since there is no operation or update of the screen content for a period of time, the user will see half of the screen, and the display device will automatically turn off or enter the power saving/sleep mode.

2. Some users watch animations or movies through a display device (may be equipped with a computer or other electronic circuit devices). Usually there will be a long period of time during viewing and will not carry out any operations on the computer or other electronic circuit devices connected to the display device. In this way, the display device often directly enters the power saving/sleep mode.

Based on the above, most manufacturers or users will set the detection time (usually several minutes or even several hours) to overcome the above problems. However, if the setting is too short, the user may often encounter the display device automatically shutting down or entering the power saving/sleep mode due to this power saving mechanism when viewing the display device. The benefit of electricity doesn't help much.

Contents of the invention

In view of this, the present invention provides a display device and a control method for controlling the display device, a projection device and a control method for controlling the projection device.

The invention provides a display device, which includes at least one sensor, a processing unit, and a control unit. The sensor is used for detecting a human body. The processing unit is connected to the sensor for capturing and processing signals from the sensor to obtain sensing data. The control unit is coupled to the processing unit for analyzing and judging whether the human body enters or leaves the sensing range of the sensor according to the sensing data. When the control unit determines that the human body is away from the sensing range for or exceeds the first preset time length, then turn off the display device or cause the display device to enter a power saving/sleep mode; and when the control unit determines that the human body enters the sensing range When the measurement range reaches or exceeds the second preset time length, the display device is turned on. Wherein, the sensing distance can be customized by the user or set by the manufacturer, or even determined by the predetermined software and hardware architecture of the product itself.

The present invention further provides a control method for controlling a display device, which includes: judging whether a human body enters or leaves the sensing range of the display device. When it is judged that the human body is far away from the sensing range and has reached or exceeded the first preset time, then turn off the display device, cause the display device to enter a power saving/sleep mode or adjust the brightness of the display device to be lower; and when it is judged When the human body enters the sensing range for or exceeds the second preset time, the display device is turned on. Wherein, the sensing distance can be customized by the user or set by the manufacturer, or even determined by the predetermined software and hardware architecture of the product itself.

The present invention also provides a projection device, which includes a projection light source, at least one sensor, a processing unit, and a control unit. The sensor is used for detecting a projection surface when the projection device is in a power-on state. The processing unit is connected to the sensor for capturing and processing signals from the sensor to obtain sensing data. The control unit is connected to the processing unit and the projection light source for analyzing and judging the distance between the projection device and the projection surface according to the sensing data. When the control unit judges that the distance between the projection device and the projection surface falls within the preset distance range for the first preset time, it controls the brightness of the projection light source according to the distance between the projection device and the projection surface; and when the control unit When the unit determines that the distance between the projection device and the projection surface exceeds or is less than the preset distance range for a second preset time, it causes the projection device to be turned off, enters power saving/sleep mode, enters standby mode, and turns off the projection The light source or the projection light source is set to a specific brightness. Wherein, the sensing distance can be customized by the user or set by the manufacturer, or even determined by the predetermined software and hardware architecture of the product itself.

The present invention further provides a control method for controlling a projection device, wherein the projection device includes a projection light source, and the control includes: when the projection device is in the power-on state, judging the distance between the projection device and the projection surface; When the distance between the projection device and the projection surface falls into the preset distance range and has reached the first preset time, the brightness of the projection light source of the projection device is controlled according to the distance between the projection device and the projection surface; and when it is judged that the projection device When the distance from the projection surface exceeds or falls short of the preset distance range for a second preset time, the projection device is turned off, enters power saving/sleep mode, enters standby mode, turns off the projection light source or sets the projection light source to fixed at a certain brightness. Wherein, the sensing distance can be customized by the user or set by the manufacturer, or even determined by the predetermined software and hardware architecture of the product itself.

The invention also provides an electronic device, which includes an image device, at least one sensor, a processing unit, and a control unit. The image device is used to display an image. The sensor is used for sensing an object. The processing unit is connected to the sensor for capturing and processing signals from the sensor to obtain sensing data. The control unit is connected to the processing unit for analyzing and judging the relative distance between the electronic device and the object according to the sensing data, so as to control the brightness of the image displayed by the image device.

It should be understood that the above general description and the following specific embodiments are only illustrative and explanatory, and cannot limit the scope of the present invention.

Description of drawings

FIG. 1 is a schematic view of the front appearance of a display device according to an embodiment of the present invention;

2 is a schematic diagram of the relative relationship between the display device and the user according to an embodiment of the present invention;

FIG. 3 is a block diagram of the interior of a display device according to an embodiment of the present invention;

FIG. 4 is a control method for controlling a display device according to an embodiment of the present invention;

FIG. 5 is a schematic view of the front appearance of a projection device according to an embodiment of the present invention;

6 is a schematic diagram of the relative relationship between the projection device and the projection surface according to an embodiment of the present invention;

FIG. 7 is a block diagram of the interior of a projection device according to an embodiment of the present invention;

FIG. 8 is a control method for controlling a projection device according to an embodiment of the present invention.

Explanation of reference signs

100-display device; 201-human body (user); 301, 701-sensor;

303, 703-processing unit; 305, 705-control unit; 307-display module;

500-projection device; 707-projection light source; F-frame;

AA-display area; d-distance; SR-sensing range;

SS-signal from sensor; SD-sensing data; 501-projection surface;

S401-S409: steps in the flow chart of a control method for controlling a display device according to an embodiment of the present invention;

S801-S809: steps in the flow chart of a control method for controlling a projection device according to an embodiment of the present invention.

Detailed ways

Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. In addition, wherever possible, elements/components using the same reference numerals in the drawings and embodiments represent the same or similar parts.

FIG. 1 is a schematic view of the front appearance of a display device according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a relative relationship between a display device and a user according to an embodiment of the present invention. FIG. 3 is a block diagram of an internal display device according to an embodiment of the present invention. Please refer to FIGS. 1 to 3 together. The display device 100 includes at least one sensor 301 , a processing unit 303 , a control unit 305 and a display module 307 .

The sensor 301 may be installed above (but not limited to) the front frame F of the display device 100 to detect a human body 201 (ie, a user). In this embodiment, the sensor 301 can be an optical sensor, a photoelectric sensor, an ultrasonic sensor, an electromagnetic wave sensor, a mechanical wave sensor, a temperature sensor or an image sensor, but both Not limited to this. In addition, the number and position of the sensors 301 installed on the front frame F of the display device 100 can be determined according to actual design requirements.

The processing unit 303 is connected to the sensor 301 for capturing and processing the signal SS from the sensor 301 to obtain the sensing data SD. The control unit 305 is connected between the processing unit 303 and the display module 307, and is used for analyzing and judging whether the human body 201 enters or leaves the sensing range SR of the sensor 301 according to the sensing data SD obtained by the processing unit 303, wherein The size of the sensing range SR of the sensor 301 can be known according to the characteristics of the sensor 301, and can be customized by the user or set by the manufacturer, or even determined by the predetermined software and hardware architecture of the product itself.

In this embodiment, when the control unit 305 judges that the human body 201 is away from the sensing range SR of the sensor 301 for a first preset time or more according to the sensing data SD obtained by the processing unit 303 (the first The preset time can be a fixed time, or a variable time that can be adjusted by the user), the control unit 305 will turn off the display device 100 or cause the display device 100 to enter the power saving/sleep mode.

On the other hand, when the control unit 305 determines according to the sensing data SD obtained by the processing unit 303 that the human body 201 has entered the sensing range SR of the sensor 301 for or over a second preset time (the second preset Assuming that the time can also be a fixed time, or a variable time that can be adjusted by the user), the control unit 305 will turn on the display device 100, and cause the display module 307 to display images in the display area AA to the user watch.

It can be known from this that once the user enters the sensing range SR of the sensor 301 for or exceeds a second predetermined period of time, the control unit 305 will turn on the display device 100 . In this way, if the user uses the display device 100 (possibly with a computer or other electronic circuit device) to read information, watch animation or watch movies, as long as the user remains within the sensing range SR of the entry sensor 301 And under the condition of reaching or exceeding a second preset time, the control unit 305 will cause the display device 100 to remain in the normal operation mode, so that the display device 100 will not turn itself off or enter the power saving/sleep mode, thereby improving the performance of the display device 100. Problems mentioned in the prior art.

In addition, once the user stays away from the sensing range SR of the sensor 301 for or over a first preset period of time, the control unit 305 will turn off the display device 100 or lower the brightness of the display module 307 so that the display device 100 enters the Power saving/sleep mode. In this way, if the user uses the display device 100 (possibly with a computer or other electronic circuit device) to read information, watch animation or watch a movie, and suddenly something happens, he leaves the sensing range SR of the sensor 301 for a period of time. When the preset time exceeds, the control unit 305 will turn off the display device 100 or cause the display device 100 to enter a power saving/sleep mode, so as to save power.

In another embodiment of the present invention, the control unit 305 can also analyze and judge the distance d between the human body 201 and the sensor 301 according to the sensing data SD obtained by the processing unit 303, and then control the display module 307 to adjust the brightness. In this embodiment, the display module 307 is generally composed of a display panel, a backlight module and a plurality of drivers. Also because of this, when the control unit 305 judges that the distance d between the human body 201 and the sensor 301 falls within the sensing range SR of the sensor 301 or falls within a distance d according to the sensing data SD obtained by the processing unit 303 For a specific distance range, according to the distance d, through image processing, gamma (Gamma) voltage adjustment, gray level (gray level) voltage adjustment, or backlight module brightness adjustment, to dynamically The brightness of the display module 307 is adjusted, for example, the brightness of the display module 307 is gradually increased (eg, linearly or non-linearly, but not limited thereto).

On the other hand, when the control unit 305 judges that the distance d between the human body 201 and the sensor 301 exceeds the sensing range SR of the sensor 301 according to the sensing data SD obtained by the processing unit 303, the distance d d and dynamically adjust the brightness of the display module 307 through image processing, gamma voltage adjustment, grayscale voltage adjustment, or backlight module brightness adjustment (but not limited thereto). , such as gradually decreasing (eg linearly or non-linearly decreasing, but not limited to) the brightness of the display module 307 .

Based on the contents disclosed in the above embodiments, FIG. 4 is a control method for controlling a display device according to an embodiment of the present invention. Referring to FIG. 4 , the control method for controlling the display device in this embodiment includes: determining whether the human body enters or leaves the sensing range of the display device (step S401 ). When it is determined in step S401 that the human body is far away from the sensing range of the display device, continue to judge whether the human body is far away from the sensing range of the display device for a first preset time (step S403), and the first preset time may be a fixed period of time , or a variable amount of time that can be adjusted by the user. When it is determined in step S403 that the human body is away from the sensing range of the display device for more than/has reached the first preset time, then turn off the display device or reduce the brightness of the display device to cause the display device to enter the power saving/sleep mode (step S405). In addition, when it is determined in step S403 that the human body is far away from the sensing range of the display device for less than the first preset time, return to step S401.

On the other hand, when it is judged in step S405 that the human body enters the sensing range of the display device, then continue to judge whether the human body enters the sensing range of the display device for a second preset time (step S407), the second preset time is also It can be a fixed amount of time, or a variable amount of time that can be adjusted by the user. When it is determined in step S407 that the sensing range of the human body entering the display device exceeds/has reached the second preset time, the display device is turned on, and the distance between the human body and the display device is analyzed to determine when the distance falls within the range of the display device. When the sensing range is within a specific distance range, the display brightness of the display device is dynamically adjusted (step S409 ). In addition, when it is determined in step S407 that the human body has not entered the sensing range of the sensor for a second preset time, the process returns to step S401. In this embodiment, when the distance between the human body and the display device falls within the sensing range of the display device or a specific distance range, for example, the brightness of the display device can be gradually increased; in addition, when the distance between the human body and the display device exceeds When displaying the sensing range of the display device or a specific distance range, for example, the brightness of the display device can be gradually reduced, but it is not limited thereto.

FIG. 5 is a schematic front view of a projection device according to an embodiment of the present invention. FIG. 6 is a schematic diagram of the relative relationship between the projection device and the projection surface according to an embodiment of the present invention. FIG. 7 is a block diagram of the interior of a projection device according to an embodiment of the present invention. Please refer to FIGS. 5 to 7 together. The projection device 500 can be, for example, a projector, a single-shot projector, a slide show player or a cinema movie player, and includes at least one sensor 701, a processing unit 703, and a control unit 705. and a projection light source 707 .

The sensor 701 can be installed above the front frame F of the projection device 500 (but not limited thereto), and is used to detect a projection surface 501 (such as a curtain, but not limited to) when the projection device 500 is turned on without limitation). In this embodiment, the sensor 701 can be an optical sensor, a photoelectric sensor, an ultrasonic sensor, an electromagnetic wave sensor, a mechanical wave sensor, a temperature sensor or an image sensor, but neither limited to this. In addition, the number and position of the sensors 701 installed on the front frame F of the projection device 500 can be determined according to actual design requirements.

The processing unit 703 is connected to the sensor 701 for capturing and processing the signal SS from the sensor 701 to obtain the sensing data SD. The control unit 705 is connected to the processing unit 703 and the projection light source 707 for analyzing and judging the distance d between the projection device 500 and the projection surface 501 according to the sensing data SD obtained by the processing unit 703 . In this embodiment, when the control unit 705 determines that the distance d between the projection device 500 and the projection surface 501 falls within a preset distance range for a first preset time according to the sensing data SD obtained by the processing unit 303 (The first preset time can be a fixed time, or a variable time that can be adjusted by the user, and the preset distance range can be determined according to the actual situation), then the control unit 705 will determine according to the projection device 500 The brightness of the projection light source 707 is controlled by the length of the distance d from the projection surface 501 .

Therefore, when the control unit 705 determines that the distance d between the projection device 500 and the projection surface 501 falls within the aforementioned preset distance range and the longer the distance d is, the control unit 705 will gradually increase (such as a linear or non-linear increase, but not limited thereto) the brightness of the projection light source 707 . In addition, when the control unit 705 determines that the distance d between the projection device 500 and the projection surface 501 falls within the aforementioned preset distance range and the shorter the distance d is, the control unit 705 will gradually decrease (for example, linearly or nonlinearly, but not limited thereto) the brightness of the projection light source 707 .

In this embodiment, the control unit 705 can control the brightness of the projection light source 707 through image processing, gamma voltage adjustment, grayscale voltage adjustment, projection light source brightness adjustment, or the lens of the projection device. Focus adjustment can be used to control, but it is not limited to this.

On the other hand, when the control unit 705 determines according to the sensing data SD obtained by the processing unit 703 that the distance d between the projection device 500 and the projection surface 501 exceeds or is less than the aforementioned preset distance range for a second preset time (The second preset time can also be a fixed time, or a variable time that can be adjusted by the user), then the control unit 705 will turn off the projection device 500, enter the power saving/sleep mode, and enter the standby mode . Turn off the projection light source 707 or set the projection light source 707 to a specific brightness.

It can be seen from this that once the distance d between the projection device 500 and the projection surface 501 falls within the aforementioned preset distance range for a first preset time, the control unit 705 will d to adjust the brightness of the projection light source 707 adaptively. In this way, if the user uses the projection device 500 (possibly with a computer or other electronic circuit device) to read information, watch animation or watch movies, as long as the distance d between the projection device 500 and the projection surface 501 is kept at Under the condition that the projection device 500 stays in the normal operation mode after entering the preset distance range for a first preset period of time, the control unit 705 will prevent the projection device 500 from shutting itself down or entering power saving/sleep/standby mode. model.

In addition, once the distance d between the projection device 500 and the projection surface 501 exceeds or falls short of the aforementioned preset distance range for a second preset time, the control unit 705 will shut down the projection device 500, enter the power saving/sleep mode, Entering the standby mode, turning off the projection light source 707 or setting the projection light source 707 at a specific brightness can avoid the possibility of the projection light source 707 being burned, and can also achieve the purpose of saving power.

Based on the contents disclosed in the above embodiments, FIG. 8 is a control method for controlling a projection device according to an embodiment of the present invention. Referring to FIG. 8 , the control method for controlling the projection device in this embodiment includes: determining whether the distance between the projection device (with a projection light source) and the projection surface falls within a preset distance range (step S801 ). When it is determined in step S801 that the distance between the projection device and the projection surface falls within the preset distance range, continue to determine whether the distance between the projection device and the projection surface falls within the preset distance range for a first preset time ( Step S803), the first preset time can be a fixed time, or a variable time that can be adjusted by the user, and the preset distance range can be determined according to the actual situation.

When it is determined in step S803 that the distance between the projection device and the projection surface falls within the preset distance range and has reached the first preset time, the brightness of the projection light source of the projection device is controlled according to the distance between the projection device and the projection surface (S805). Therefore, when it is judged that the distance between the projection device and the projection surface falls within the preset distance range and the distance is longer, the brightness of the projection light source is gradually increased; and when it is judged that the distance between the projection device and the projection surface falls within When the distance is preset and the distance is shorter, the brightness of the projection light source is gradually reduced. In addition, when it is determined in step S803 that the distance between the projection device and the projection surface falls within the preset distance range for less than the first preset time, then return to step S801.

On the other hand, when it is determined in step S801 that the distance between the projection device and the projection surface does not fall within (that is, exceeds or is less than) the preset distance range, continue to determine that the distance between the projection device and the projection surface exceeds or is less than the preset distance range. It is determined whether the distance range reaches a second preset time (step S807). The second preset time can also be a fixed time or a variable time that can be adjusted by the user. When it is determined in step S807 that the distance between the projection device and the projection surface exceeds or is less than the preset distance range for a second preset time, the projection device is turned off, enters power saving/sleep mode, enters standby mode, and turns off projection light source or set the projection light source at a specific brightness (S809). In addition, when it is determined in step S807 that the distance between the projection device and the projection surface exceeds or is less than the preset distance range but has not reached the second preset time, then return to step S801.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (23)

1. A display device, comprising: At least one sensor is used to generate a sensing signal corresponding to the distance between the display device and a human body; a processing unit connected to the sensor for processing the sensing signal to obtain sensing data; as well as, A control unit, connected to the processing unit, for analyzing and judging whether the human body enters or leaves a sensing range of the sensor according to the sensing data, and when it is judged that the human body is far away from the sensing range has reached or When a first preset time is exceeded, turn off the display device or cause the display device to enter a power saving/sleep mode, Wherein, when the control unit judges that the human body enters the sensing range and has reached or exceeded a second preset time, the display device is turned on, and as long as the human body continues to enter the sensing range and reaches or exceeds the Under the condition of the second preset time, the control unit will cause the display device to remain in a normal operation mode, so that the display device will not turn itself off or enter the power saving/sleep mode. 2. The display device according to claim 1, further comprising: A display module is connected to the control unit, wherein the control unit is also used to control the brightness of the display module. 3. The display device according to claim 2, wherein the control unit lowers the brightness of the display module, thereby making the display device enter the power saving/sleep mode. 4. The display device according to claim 1, wherein the control unit further analyzes a distance between the human body and the sensor according to the sensing data, and adjusts the brightness of the display module accordingly. 5. The display device according to claim 4, wherein when the control unit determines that the distance falls within a specific distance range or falls within the sensing range, it dynamically adjusts the display module's position according to the distance brightness. 6. The display device according to claim 1, wherein the first preset time and the second preset time are a fixed time or a variable time. 7. The display device according to claim 1, wherein the sensor comprises an optical sensor, a photoelectric sensor, an ultrasonic sensor, an electromagnetic wave sensor, a mechanical wave sensor, a temperature sensor or an image sensor. 8. A control method for controlling a display device, the control method comprising: Judging whether a human body enters or leaves a sensing range of the display device, wherein: When it is determined that the human body is far away from the sensing range for or over a first preset time, then turn off the display device or cause the display device to enter a power saving/sleep mode; and, When it is judged that the human body enters the sensing range and has reached or exceeded a second preset time, the display device is turned on, and as long as the human body continues to enter the sensing range and reaches or exceeds the second preset time Under the condition of time, the display device is kept in a normal operation mode, so that the display device does not turn itself off or enter the power saving/sleep mode. 9. The control method for controlling the display device according to claim 8, wherein the step of causing the display device to enter the power saving/sleep mode comprises: reducing the brightness of the display device, so that the display device enters the power saving/sleep mode. 10. The control method for controlling the display device according to claim 9, further comprising: A distance between the human body and the display device is analyzed, and the display brightness of the display device is adjusted accordingly. 11. The control method for controlling the display device according to claim 10, wherein when it is determined that the distance falls within the sensing range or a specific distance range, the display brightness of the display device is dynamically adjusted. 12. The method for controlling the display device according to claim 8, wherein the first preset time and the second preset time are a fixed time or a variable time. 13. A projection device comprising: a projection light source; At least one sensor is used to generate a sensing signal when the projection device is turned on, and the sensing signal corresponds to the distance between the projection device and a projection surface; a processing unit connected to the sensor for capturing and processing the sensing signal to obtain sensing data; and, A control unit, connected to the processing unit and the projection light source, for analyzing and judging a distance between the projection device and the projection surface according to the sensing data, so that when the distance falls within a preset distance range interval When a first preset time is reached, the projection brightness is adjusted according to the length of the distance; and when the control unit determines that the distance exceeds the preset distance range for a second preset time, the projection device turn off, enter a power saving/sleep mode, enter a standby mode, turn off the projection light source or set the projection light source at a specific brightness, Wherein, as long as the distance between the projection device and the projection surface remains within the aforementioned preset distance range and reaches the first preset time, the control unit will cause the projection device to remain at a normal operation mode, so that the projection device cannot be turned off by itself or enter the power saving/sleep mode and the standby mode. 14. The projection device according to claim 13, wherein when the control unit determines that the distance falls within the preset distance range and the distance is longer, the brightness of the projection light source is increased. 15. The projection device according to claim 13, wherein when the control unit determines that the distance falls within the preset distance range and the distance is shorter, the brightness of the projection light source is reduced. 16. The projection device according to claim 13, wherein the first preset time and the second preset time are a fixed time or a variable time. 17. The projection device according to claim 13, wherein the sensor comprises an optical sensor, a photoelectric sensor, an ultrasonic sensor, an electromagnetic sensor, a mechanical sensor, a temperature sensor or an image sensor. 18. The projection device according to claim 13, wherein the projection device comprises a projector, a single shot projector, a slide show player or a cinema movie player. 19. A control method for controlling a projection device, the projection device comprising a projection light source, the control method comprising: When the projection device is turned on, determine a distance between the projection device and a projection surface; When it is determined that the distance falls within a preset distance range for a first preset time, then controlling the brightness of a projection light source of the projection device according to the length of the distance; and, When it is determined that the distance exceeds or is less than the preset distance range and has reached a second preset time, the projection device is turned off, enters a power saving/sleep mode, enters a standby mode, turns off the projection light source, or turns off the projection device. The projection light source is set at a specific brightness, Wherein, as long as the distance between the projection device and the projection surface remains within the aforementioned preset distance range and reaches the first preset time, the projection device remains in a normal operation mode, thereby The projection device cannot be turned off by itself or enter the power saving/sleep mode and the standby mode. 20. The control method for controlling the projection device according to claim 19, wherein when it is determined that the distance falls within the preset distance range and the distance is longer, the brightness of the projection light source is gradually increased. 21. The control method for controlling the projection device according to claim 19, wherein when it is determined that the distance falls within the preset distance range and the distance is shorter, the brightness of the projection light source is gradually reduced. 22. The control method for controlling the projection device according to claim 19, wherein the first preset time and the second preset time are a fixed time or a variable time. 23. An electronic device comprising: an image device for displaying an image; At least one sensor is used to generate a sensing signal corresponding to the distance between an object and the electronic device; a processing unit connected to the sensor for capturing and processing signals from the sensor to obtain sensing data; and, a control unit, connected to the processing unit, for analyzing and judging a relative distance between the electronic device and the object according to the sensing data, so as to control the brightness of the image displayed by the imaging device, Wherein, when the control unit judges that the object enters a sensing range of the sensor for a preset time or exceeds a preset time, the imaging device is turned on, and as long as the object continues to enter the sensing range to reach Or when the preset time is exceeded, the control unit will cause the imaging device to remain in a normal operation mode, so that the imaging device will not shut itself down or enter a power saving/sleep mode.

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