CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serial no. 201910783200.1, filed on Aug. 23, 2019. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

The disclosure relates to an optical device and a parameter adjusting method thereof, and in particular, to a projection device and a brightness adjusting method thereof.

Description of Related Art

Existing projection devices adjust brightness of a projection image by utilizing ambient light sensing feedback, and for such a mechanism, a photosensitive element needs to be additionally disposed on the projection device. The projection device detects intensity of ambient light according to the photosensitive element to adjust brightness of a light source in the projection device, so as to avoid discomfort of human eyes caused by excessive projection brightness in a relatively dark environment, and meanwhile reduce the brightness to achieve the effect of energy saving. Generally, the photosensitive element built in the projection device is disposed on a back side opposite to the projection picture. When lamps in a meeting room are turned on, the photosensitive element senses that the brightness of ambient light is increased. The projection device increases the brightness of the light source according to the ambient light sensing feedback, so as to meet the requirement of users. When the lamps in the meeting room are turned off, the photosensitive element senses that the brightness of the ambient light is reduced, and the projection device reduces the brightness of the light source according to the ambient light sensing feedback, so as to protect the human eyes. However, if only a front row of the lamps in the meeting room are turned off, because the disposition position of the photosensitive element is on the back side of the projection device, the photosensitive element cannot sense the accurate ambient light at a position where the users are located, and therefore, the brightness of the light source of the projection device cannot be changed, causing discomfort of the eyes of the users, and as for the users closer to the projection image, intensive discomfort of the eyes will be caused. Moreover, for such a manner in which the photosensitive element is additionally installed on the projection device, the installation position on the projection device is very important. If the photosensitive element is installed on an upper cover of the projection device, and the projection device is hung on a ceiling, such a disposing manner causes the photosensitive element to face and get close to the ceiling, then the photosensitive element cannot sense the real ambient brightness, misjudgment is easily caused. As a result, the brightness adjustment effect is poor.

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 disclosure are acknowledged by a person of ordinary skill in the art.

SUMMARY OF THE DISCLOSURE

The disclosure provides a projection device and a brightness adjusting method thereof, which may cause brightness of a light source of the projection device to be properly adjusted according to environmental factors.

Other objectives and advantages of the disclosure may be more comprehensible from technical features disclosed in the disclosure.

In order to achieve one or some of or all the foregoing objectives or other objectives, an embodiment of the disclosure provides a projection device, including a projection unit, an image capture device and a control unit. The projection unit includes a light source. The projection unit is configured to project an image picture to a projection area. The image capture device is configured to obtain an image capture picture including the image picture in an image capture range. The image capture range is larger than the projection area. The control unit is coupled to the image capture device. The control unit is configured to determine, according to a picture variation value of the image capture picture, whether to adjust brightness of the light source.

In order to achieve one or some of or all the foregoing objectives or other objectives, an embodiment of the disclosure provides a brightness adjusting method used for the projection device. The projection device includes a light source. The brightness adjusting method includes: projecting an image picture to a projection area; obtaining an image capture picture including the image picture in an image capture range; and determining, according to a picture variation value of the image capture picture, whether to adjust brightness of the light source. The image capture range is larger than the projection area.

Based on the above, embodiments of the disclosure at least have one of the following advantages or effects. The projection device determines an environmental change by utilizing the image capture device to obtain the image capture picture, so that the brightness of the light source of the projection device is properly adjusted according to ambient brightness.

Other objectives, features and advantages of the disclosure will be further understood from the further technological features disclosed by the embodiments of the disclosure wherein there are shown and described exemplary embodiments of this disclosure, simply by way of illustration of modes best suited to carry out the disclosure.

