Zooming method and apparatus for portable projection system

Abstract

The invention provides a zooming method of portable projection system and zooming device. The zooming device comprises: object lens behind the DMD of projection system, torquer with bearing object lens and zooming control system for controlling the movement of the torquer, wherein the zooming control system comprises a displacement detecting module, error servo algorithm module and error compensation instruction module. The zooming method comprises: (1) measuring the distance between the object lens and projection screen by displacement detecting module; (2) calculating the corresponding deviation compensation driving voltage required by the position error using error servo algorithm module; (3) the error compensation instruction module sending command to control the movement of torquer at optimal space position, to implement the automatically zooming. The focus can be changed at real time and the displacement accuracy of object lens can be 0.23-0.40um. The invention can quickly and effectively perform automatic zooming in portable projection system and satisfy the requirement of automatic zooming of portable projection system using device such as cellphone, pocket PC.

Description

technical field [0001] The invention relates to zooming of a projection system, in particular to a zooming method and a zooming device of a portable projection system. Background technique [0002] Using projection imaging technology that combines mobile phones, palmtop computers and other portable devices with digital light processing chips, it can project video images close to DVD quality. In order to obtain a clear projection imaging effect, the optical components are required to have a good zoom capability. The traditional zoom system uses a mechanical zoom device, such as a cam mechanism and a rail chute mechanism, which needs manual adjustment to achieve the best effect. This mechanism is difficult to achieve fast and high-precision positioning, cannot perform adaptive automatic zoom, and is too large , It is difficult to install on portable devices such as mobile phones and PDAs. Existing typical portable projection devices using mobile phones and other equipment ar...

AI Technical Summary

Problems solved by technology

The traditional zoom system uses a mechanical zoom device, such as a cam mechanism and a rail chute mechanism, which needs manual adjustment to achieve the best effect. This mechanism is difficult to achieve fast and high-precision positioning, cannot perform adaptive automatic zoom, and is too large , difficult to install on portable devices such as mobile phones and PDAs

Existing typical portable projection devices using mobile phones and other equipment are mainly composed of a light source modulated by information, a color wheel, an optical element group and a digital micromirror device (Digital Micromirror Device, DMD for short), and do not have the function of automatic zooming.

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