Method of stabilizing resonant frequency and resonant scanner using the same
First Claim
1. A resonant scanner which comprises an oscillating reflective mirror that reflects incident light so that it is deflected in a one-dimensional direction to perform optical scanning, a resonant drive means that causes said reflective mirror to oscillate at an inherent resonant frequency, a control means for controlling said resonant drive means, a signal generator means which generates a signal having a frequency different from said resonant frequency and a signal switching means that allows said signal to flow into said resonant drive means when said reflective mirror is in a non-scanning mode.
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Abstract
A method of the present invention for stabilizing the resonant frequency of a resonant scanner is that thermal energy of the same amount as the heat generated in an optical scanning mode is applied to the scanner section in a non-scanning mode to insure that the variation of the temperature of the resonant light deflector will lie within a predetermined range, whereby the resonant frequency of the oscillation of the reflecting mirror is stabilized. The resonant scanner of the present invention in which the scanner section is heated in the non-scanning mode by supplying the drive coil with an electric current that has a non-resonant frequency or with the heater is constructed. The resonant scanner using the method is capable of achieving precise optical scanning that has an improved dimensional precision in the sub-scanning direction.
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Citations
4 Claims
- 1. A resonant scanner which comprises an oscillating reflective mirror that reflects incident light so that it is deflected in a one-dimensional direction to perform optical scanning, a resonant drive means that causes said reflective mirror to oscillate at an inherent resonant frequency, a control means for controlling said resonant drive means, a signal generator means which generates a signal having a frequency different from said resonant frequency and a signal switching means that allows said signal to flow into said resonant drive means when said reflective mirror is in a non-scanning mode.
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