Lens cap device and projection machine

Abstract

The invention discloses a lens cap device, which is applied to a projection machine and comprises a lens cap, a locating column, an elastic part, a sensitive film and a metal hook, wherein one end of the elastic part is fixed at a shell of the projection machine and the other end of the elastic part is connected with one end of the lens cap; the locating column and the sensitive film are arrangedat the inner side of the lens cap; and the metal hook consists of two metal strips with different coefficients of thermal expansion, and comprises a body and a clamping part. When the projection machine is not turned on, the metal hook can be contacted with the sensitive film and the locating column can be clamped by the clamping part; and when the projection machine is turned on, the metal hook is heated and the temperature of the metal hook is raised, then the metal hook bends towards the metal strip with smaller coefficient of thermal expansion, and the locating column is released by the clamping part. The lens cap device can automatically open the lens cap and has a simple structure and a low manufacture cost; and moreover, the process of opening the lens cover does not consume energy, thereby reducing the use cost. The invention also discloses the projection machine.

Description

technical field [0001] The invention belongs to the technical field of lens covers, in particular to a lens cover device and a projector. Background technique [0002] Projector is a video equipment commonly used by modern people. It is widely used in presentations, conferences or education and training. The projector can project data on a larger plane or screen. During the use of the projector, the image must be transmitted to the outside world through the lens. If the surface of the lens is scratched or covered with dust, the image projected by the projector through the lens will be blurred. Therefore, it is necessary to keep the lens clean and prevent external dust from adhering to the lens surface. [0003] The projector at least includes: a casing; a lens arranged in the casing; a projection opening opened on the casing corresponding to the position of the lens; an exhaust pipeline for heat dissipation; and an air outlet opened on the casing. The current lens cover ma...

AI Technical Summary

Problems solved by technology

[0004] But above-mentioned first kind of lens cover can't be opened automatically when projector starts to work, and although second kind of lens cover can be opened automatically, will configure power part for lens cover in a...

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