Patent ID: 7969559

Claim:
A laser distance measuring apparatus for measuring a distance from a target comprising: an emitter, to emit measuring light; a first liquid crystal display module, comprising a second state and a first state; a second liquid crystal display module, comprising a second state and a first state; a receiver, to receive the reference light passing through the second liquid crystal display module by the measuring light, and a reflected light reflected from the target by the measuring light, and outputting a reference signal and a reflected signal based on intensity of the reference light and the reflected light; and a control unit, to set the first liquid crystal display module to the first state and the second liquid crystal display module to the second state, set the first liquid crystal display module to the second state and the second liquid crystal display module to the first state in order to receive the reference signal, compare the reflected signal and a predetermined value, and decrease a transmittance of the first liquid crystal display module when the reflected signal is larger than the predetermined value.