Title:
VARIABLE FOCAL LENGTH LENS SYSTEM USING QUASI-SINUSOIDAL PERIODIC INTENSITY MODULATED LIGHT
Document Type and Number:
Japanese Patent JP2019191180
Kind Code:
A
Abstract:
To provide a vision system that can obtain a uniform image exposure.SOLUTION: A vision system includes: a variable focal length (VFL) lens system; a light source; an exposure time control unit; and a camera. The VFL lens system includes a tunable acoustic gradient (TAG) lens that is controlled so as to conduct a nominally sinusoidal focus position modulation. The light source includes a continuous illumination source connected to a light source drive unit giving corresponding quasi-sinusoidal periodic intensity modulated light by driving the continuous illumination source based on a quasi-sinusoidal periodic drive function. The camera is configured to provide a workpiece image based on an image exposure inputting workpiece image light arising from illuminating a workpiece with the quasi-sinusoidal periodic intensity modulated light. By using the quasi-sinusoidal periodic intensity modulated light in combination with the nominally sinusoidal focus position modulation, uniform image exposures and other advantages (that is, by avoiding over-exposure at a focus extreme of the TAG lens, and the like) can be obtained.SELECTED DRAWING: Figure 1
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Inventors:
TED STATON COOK
Application Number:
JP2019085170A
Publication Date:
October 31, 2019
Filing Date:
April 26, 2019
Export Citation:
Assignee:
MITUTOYO CORP
International Classes:
G01B11/24; G02B3/14; G02B7/28; G02B7/36; G03B7/083; G03B9/08; G03B13/36; H04N5/225; H04N5/232; H04N5/235
Attorney, Agent or Firm:
Yoshiyuki Inaba
Toshifumi Onuki
Akihiko Eguchi
Kazuhiko Naito
Toshifumi Onuki
Akihiko Eguchi
Kazuhiko Naito