Projection device with automatic focusing function and automatic focusing method thereof

Abstract

The invention relates to a projection device with an automatic focusing function and an automatic focusing method thereof. The steps are as follows: imaging an image which is projected on a screen by a first imaging lens by utilizing a second imaging lens on an image sensing unit; moving the second imaging lens, stating the image sensing unit to capture an image produced by the second imaging lens each time after the second imaging lens is moved, and calculating the definitions of the captured image; and comparing the definitions and obtain a largest value of all, and the position of the second imaging lens which corresponds to the largest value is a focusing position of the second imaging lens. Sequentially, moving the first imaging lens, each time after the first imaging lens is moved, capturing an image produced by the second imaging lens and calculating the definitions of the images; comparing the definitions of the images so as to obtain the largest value of all, and the positionof the first imaging lens which corresponds to the largest value is a focusing position of the first imaging lens.

Description

technical field [0001] The present invention relates to a projection device, in particular to a projection device with an automatic focus function and an automatic focus method thereof. Background technique [0002] Projectors have been widely used in business, education, and life. Especially for the convenience of portability, many miniaturized projectors have appeared on the market in recent years. Among them, there are still photography functions, dynamic photography functions or mobile phones in one. machine. [0003] In the use of the projector, in order to project a clear image on the screen, the user must manually adjust the position of the projection lens of the projector on its optical axis so that the image surface of the projection lens is on the same plane as the screen , which is commonly referred to as focus. Most of the projectors currently sold on the market require the user to manually control the focus. [0004] As far as larger projectors are generally ...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a projection device with an automatic focus function and an automatic focus method for the defects that the projection device in the prior art cannot automatically focus, or can not detect whether the image is clear or not although it can automatically focus , to ensure that the image projected on the screen is correct and clear after the focusing action is completed

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