Three-dimensional measurement apparatus

• US 6,233,049 B1
• Filed: 03/22/1999
• Issued: 05/15/2001
• Est. Priority Date: 03/25/1998
• Status: Expired due to Term

• Current Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Original Assignee: Minolta Co., Ltd. (Konica Minolta Inc.)
• Inventors: Miyazaki, Makoto, Kondo, Takashi, Ide, Eiichi, Norita, Toshio, Tanabe, Hideki, Uchino, Hiroshi
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US09/273,544
• Time in Patent Office: 785 Days
• Field of Search: 356/376, 356/375, 356/372, 364/559, 250/234-236, 250/559.22, 250/559.19, 382/154, 382/266, 382/285, 382/286, 395/94, 395/119, 395/126
• US Class Current: 356/623
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object

Abstract

A three-dimensional measurement device employs a slit ray projection technique to optically determine a three-dimensional image. The device offers a choice in operating modes between high-speed measurement, high-resolution measurement and large dynamic range in the depth direction, to accommodate various situations. The different modes of operation are achieved by selectively modifying one or more of the scanning speed of a projected reference beam, the readout speed of a photosensor, the line width or line spacing of the photosensor, and the number of lines per image frame.

Claims

1. A three-dimensional measurement apparatus comprising:

an irradiation unit that irradiates and scans a measurement target with a reference beam;

a photosensor for receiving light reflected from a measurement target irradiated with said reference beam;

a reading unit that repeatedly reads out signals from said photosensor during the scanning of said reference beam;

an operation mode selector; and

a controller that switches the scanning speed of said reference beam and a readout operation of said photosensor in accordance with said selected operation mode.

2. The three-dimensional apparatus of claim 1, further including a processor which measures a three-dimensional shape of said measurement target based on the output signals from said photosensor.

3. A three-dimensional measurement apparatus comprising:

an irradiation unit that irradiates and scans a measurement target with a reference beam;

a photosensor for receiving light reflected from a measurement target irradiated with said reference beam;

a reading unit that repeatedly reads out signals from said photosensor during the scanning of said reference beam;

an operation mode selector; and

a controller that switches a line width for the readout of said photosensor in accordance with said selected operation mode.

4. The three-dimensional apparatus of claim 3, further including a processor which measures a three-dimensional shape of said measurement target based on the output signals from said photosensor.

5. A three-dimensional measurement apparatus comprising:

an irradiation unit that irradiates and scans a measurement target with a reference beam;

a photosensor for receiving light reflected from a measurement target irradiated with said reference beam;

a reading unit that repeatedly reads out signals from said photosensor during the scanning of said reference beam;

an operation mode selector; and

a controller that switches line spacing for the readout of said photosensor in accordance with said selected operation mode.

6. The three-dimensional apparatus of claim 5, further including a processor which measures a three-dimensional shape of said measurement target based on the output signals from said photosensor.

7. A three-dimensional measurement apparatus comprising:

an irradiation unit that irradiates and scans a measurement target with a reference beam;

a photosensor for receiving light reflected from a measurement target irradiated with said reference beam;

a reading unit that repeatedly reads out signals from said photosensor during the scanning of said reference beam;

a switching device that switches the scanning speed of said reference beam in accordance with said selected operation mode;

a switching device that switches a line width for the readout of said photosensor in accordance with said selected operation mode; and

a switching device that switches line spacing for the readout of said photosensor in accordance with said selected operation mode.

8. The three-dimensional apparatus of claim 7, further including a processor which measures a three-dimensional shape of said measurement target based on the output signals from said photosensor.

9. A three-dimensional measurement apparatus comprising:

an irradiation unit that irradiates and scans a measurement target with a reference beam;

a photosensor for receiving light reflected from a measurement target irradiated with said reference beam;

a reading unit that repeatedly reads out signals from said photosensor during the scanning of said reference beam and thereby reading out signals output therefrom;

a switching device that switches the line width of an effective light receiving region of said photosensor, as well as line spacing for the readout, in accordance with said selected operation mode; and

a switching device that switches the number of lines shifted per frame for the readout of said photosensor in accordance with said selected operation mode.

10. A three-dimensional measurement apparatus as set forth in claim 9, further including a switching device that switches the readout operation between (a) skipping intermediate lines, or (b) adding together the read out signals, when the number of lines shifted per frame is more than one.

11. The three-dimensional apparatus of claim 9, further including a processor which measures a three-dimensional shape of said measurement target based on the output signals from said photosensor.

12. A three-dimensional measurement apparatus, comprising:

an optical scanning system which scans a target object with a reference beam;

a measuring sensor that is operable in a plurality of different operating modes to repeatedly sense an image of the target object as it is being scanned by the reference beam;

a mode selector which selects one of said operating modes; and

a controller which varies at least one of (a) the number of lines in an image which are sensed in a sensing operation, (b) the width of the image that is sensed in a sensing operation, and (c) the spacing between images in successive sensing operations, in dependence upon the selected operating mode.

13. The three-dimensional measurement system of claim 12, wherein one of said operating modes is a standard operating mode and another of said modes is a high-speed mode, and said controller decreases the number of lines which are sensed in a sensing operation during said high-speed mode, relative to said standard mode.

14. The three-dimensional measurement system of claim 13, wherein said controller also decreases the width of an image that is sensed during said high-speed mode.

15. The three-dimensional measurement system of claim 13, wherein said controller also increases the spacing between images in successive sensing operations during said high-speed mode.

16. The three-dimensional measurement system of claim 12, wherein one of said operating modes is a standard operating mode and another of said modes is a high-speed mode, and said controller increases the spacing between images in successive sensing operations during said high-speed mode, relative to said standard mode.

17. The three-dimensional measurement system of claim 12, wherein one of said operating modes is a standard operating mode and another of said modes is a high-range mode, and said controller increases the width of an image that is sensed during said high-range mode, relative to said standard mode.

18. The three-dimensional measurement system of claim 12, wherein one of said operating modes is a standard operating mode and another of said modes is a high-sensitivity mode, and said controller increases the width of said reference beam during said high-sensitivity mode, relative to said standard mode.

19. The three-dimensional measurement system of claim 12, wherein one of said operating modes is a standard operating mode and another of said modes is a high-resolution mode, and said controller decreases the spacing between images in successive sensing operating during said high-resolution mode, relative to said standard mode.

20. The three-dimensional measurement apparatus of claim 12, further including a processor which determines the three-dimensional shape of the target object on the basis of the images sensed by said measuring sensor.

28. The method of claim 18, further including the step of switching the readout operation between (a) skipping intermediate lines, or (b) adding together the readout output signals, when the number of lines shifted per frame is more than one.

21. A method for measuring the three-dimensional shape of an object, comprising the steps of:

scanning a target object with a reference beam;

receiving light reflected from a target by means of a photosensor as it is being scanned with said reference beam;

repeatedly driving said photosensor during the scanning of said reference beam to thereby read output signals therefrom;

selecting an operation mode; and

switching the scanning speed of said reference beam and a readout operation of said photosensor in accordance with said selected operation mode.

22. The method of claim 21, further including the step of measuring a three-dimensional shape of said measurement target object based on the output signals from said photosensor.

23. A method for measuring the three-dimensional shape of an object, comprising the steps of:

scanning a target object with a reference beam;

receiving light reflected from a target by means of a photosensor as it is being scanned with said reference beam;

repeatedly driving said photosensor during the scanning of said reference beam to thereby read output signals therefrom;

selecting an operation mode; and

switching a line width for the readout of said photosensor in accordance with said selected operation mode.

24. The method of claim 23, further including the step of measuring a three-dimensional shape of said measurement target objet based on the output signals from said photosensor.

25. A method for measuring the three-dimensional shape of an object, comprising the steps of:

scanning a target object with a reference beam;

receiving light reflected from a target by means of a photosensor as it is being scanned with said reference beam;

repeatedly driving said photosensor during the scanning of said reference beam to thereby read output signals therefrom;

selecting an operation mode; and

switching line spacing for the readout of said photosensor in accordance with said selected operation mode.

26. The method of claim 25, further including the step of measuring a three-dimensional shape of said measurement target objet based on the output signals from said photosensor.

27. A method for measuring the three-dimensional shape of an object, comprising the steps of:

scanning a target object with a reference beam;

receiving light reflected from a target by means of a photosensor as it is being scanned with said reference beam;

repeatedly driving said photosensor during the scanning of said reference beam to thereby read output signals therefrom;

selecting an operation mode; and

switching the number of lines shifted per frame for the readout of said photosensor in accordance with said selected operation mode.

29. The method of claim 27 further including the step of measuring a three-dimensional shape of said measurement target objet based on the output signals from said photosensor.

30. A three-dimensional measurement apparatus comprising:

an irradiator for irradiating and scanning a measurement target with a reference beam;

a photosensor for receiving light reflected from a measurement target irradiated with said reference beam;

a driver for repeatedly driving said photosensor during the scanning of said reference beam and thereby reading out signals output therefrom; and

a selector for selecting an operation mode from a plurality of operation modes, the plurality of operation modes being different from each other with respect to at least one factor of measurement time, depth of measurement, resolution, sensitivity, and measurement area.