US 7,126,733 B2 · Optical deflector

Abstract

An optical deflector comprises a control means for controlling at least either a light source or a deflection means adapted to gauge the distance between the position of a deflected beam of light moving on a light receiving element in one direction and the position of another deflected beam of light moving on the light receiving element in the opposite direction and control the distance so as to make it agree with a predetermined value. Thus, the optical deflector can very accurately control the operation of the deflection means in such a way that it is not affected by changes of environmental temperature of the deflection means and the detection circuit, because a detection means for detecting the time when a beam of light passes by a predetermined angle of deflection of the deflection means is not used.

Claims4

Dependent claims

A method of controlling an optical deflector adapted to deflect light from a light source so as to make deflected beams of light scan, said method comprising:

a position detecting step of detecting a position of a deflected beam of light moving on a light receiving element in one direction and a position of another deflected beam of light moving on the light receiving element in the opposite direction;
a sensing step of sensing a phase difference between a phase as detected in said detecting step and a predefined phase;
and
a controlling step of controlling either a drive frequency being applied to said optical deflector or a modulation timing for reciprocative drawing according to an outcome of said sensing step.

1 more element

Dependencies are inferred from the claim text.

Optical deflector

Life of this patent

Optical deflector

Life of this patent

Abstract

Claims4