Title:
SURFACE INSPECTING DEVICE
Document Type and Number:
Japanese Patent JP3019552
Kind Code:
B2
Abstract:
PURPOSE: To make high speed surface inspection with high precision without using mechanical scan by providing a frequency segregation part for producing and emitting the DC component, and providing a processing part to perform length measuring computation for each modulation frequency on the basis of this DC component.
CONSTITUTION: A laser beam is modulated with different pulse frequency in this circuit configuration that is, this device is equipped with an oscillator 40 with frequency of 5, 6, 7kHz... and a driver circuit 44 to drive a laser diode(LD) 42 with these oscillation output. The laser beam generated by driving this LD 42 is received by a one-dimensional position sensing device(PSD) 28. When the reflected light is converged on the PSD 28, it emits currents i1 and i2. For example, the components of modulation frequency of 5, 6, 7kHx... are segregated from the total current value for each frequency. Thus the length measuring is conducted with segregating by the modulation frequencies. This eliminates mechanical scan to allow preventing drop of the accuracy due to rattles, etc., which enables performing the operation at a high speed.
Inventors:
Katsunori Ozawa
Youji Yamada
Nuio Tsuchida
Koji Imai
Youji Yamada
Nuio Tsuchida
Koji Imai
Application Number:
JP29445891A
Publication Date:
March 13, 2000
Filing Date:
November 11, 1991
Export Citation:
Assignee:
TOYOTA JIDOSHA KABUSHIKI KAISHA
International Classes:
G01B11/30; G01N21/88; (IPC1-7): G01B11/30
Domestic Patent References:
| JP63222202A | ||||
| JP63195774A | ||||
| JP62228902A |
Attorney, Agent or Firm:
Kenji Yoshida (2 outside)