Optical detection device and electronic equipment for detecting at least one of an X-coordinate and a Y-coordinate of an object

• US 8,384,011 B2
• Filed: 08/31/2010
• Issued: 02/26/2013
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Wada, Hideo, Yamaguchi, Akifumi, Kubo, Masaru
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US12/872,007
• Publication Number:
  US 20110141486A1
• Time in Patent Office: 910 Days
• Field of Search: 250/221, 250/216, 250/551, 250/214.R, 356/4.01, 356/11, 356/4.03, 356/614, 396 98-121
• US Class Current: 250/221
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042

Abstract

An optical detection device includes a light emitting element, which is an area sensor, a light emitting lens part for irradiating an object to be measured with a bundle of emission rays emitted from the light emitting element, a light receiving lens part for condensing reflected light from the object, a light receiving element for detecting reflected light from the object condensed by the light receiving lens part, and a signal processing section for processing a light-reception signal from the light receiving element. Based on the light-reception signal from the light receiving element, the signal processing section detects at least one of an x-coordinate or a y-coordinate of the object on an x-y coordinate plane from at least one of a light-spot position or a light-spot shape on the light receiving element.

Claims

1. An optical detection device comprising:

a light emitting element;

an irradiation optical system for applying a bundle of emission rays emitted from the light emitting element to an object to be measured;

a reflected light optical system for condensing reflected light from the object to be measured;

a light receiving element for detecting reflected light from the object to be measured condensed by the reflected light optical system; and

a signal processing section for processing a light-reception signal from the light receiving element, wherein

the light receiving element is a line sensor or area sensor for detecting an intensity distribution of reflected light from the object to be measured, and

given a z-axis that is an optical axis of a bundle of emission rays emitted from the light emitting element, an x-axis that is a straight line perpendicular to the z-axis and extending along a line direction interconnecting the light emitting element and the light receiving element, a y-axis that is a straight line passing through an intersection point of the z-axis and the x-axis and perpendicular to the z-axis and the x-axis, and given an x-y coordinate plane that is a plane containing the x-axis and the y-axis, then the signal processing section detects at least one of an x-coordinate and a y-coordinate of the object to be measured on the x-y coordinate plane from at least one of a light-spot position on the light receiving element or a light-spot shape on the light receiving element based on the light-reception signal received from the light receiving element.

2. The optical detection device as claimed in claim 1, wherein

the signal processing section computes a differential waveform of the light-spot shape on the light receiving element based on the light-reception signal from the light receiving element, and detects at least one of the x-coordinate and the y-coordinate of the object to be measured from positive and negative peak intensities of the differential waveform.

3. The optical detection device as claimed in claim 2, wherein

the light-spot position on the light receiving element is a zero-crossing position of the differential waveform of the light-spot shape on the light receiving element, and

at least one of the x-coordinate and the y-coordinate of the object to be measured is detected from the zero-crossing position of the differential waveform.

4. The optical detection device as claimed in claim 1, wherein

the light-spot position on the light receiving element is a barycentric position of a light spot on the light receiving element, and

at least one of the x-coordinate and the y-coordinate of the object to be measured is detected from the barycentric position of the light spot.

5. The optical detection device as claimed in claim 1, wherein

the light receiving element is an area sensor in which a plurality of pixels are arrayed in lines and rows in a grating form, and

the lines of the plurality of pixels arrayed in the area sensor are parallel to the x-axis and the rows of the plurality of pixels arrayed in the area sensor are parallel to the y-axis, and wherein

the signal processing section:

performs, for each of the rows parallel to the x-axis, at least one of a differential waveform computation for computing a differential waveform of a light-spot shape on pixels of the row, to detect an x-coordinate of the object to be measured from positive and negative peak intensities of the differential waveform and a barycentric position computation for detecting an x-coordinate of the object to be measured from a barycentric position of a light spot on the pixels of the line, and

performs, for each of the rows parallel to the y-axis, at least one of a differential waveform computation for computing a differential waveform of a light-spot shape on pixels of the row to detect a y-coordinate of the object to be measured from positive and negative peak intensities of the differential waveform and a barycentric position computation for detecting a y-coordinate of the object to be measured from a barycentric position of a light spot on the pixels of the line.

6. The optical detection device as claimed in claim 1, wherein

the signal processing section detects a z-coordinate in the z-axis direction of the object to be measured from the light-spot position on the light receiving element by using a triangulation method.

7. The optical detection device as claimed in claim 6, wherein

the signal processing section detects the z-coordinate in the z-axis direction of the object to be measured when the object to be measured is irradiated with the entire bundle of emission rays emitted from the light emitting element or when the positive and negative peak intensities of the light-spot shape on the light receiving element are roughly equal to each other.

8. The optical detection device as claimed in claim 1, wherein

the signal processing section detects one of a moving direction and a moving speed of the object to be measured based on a difference in at least one of the x-coordinate and the y-coordinate of the object to be measured on the x-y coordinate plane between start and end of a specified time duration.