Method for measuring distance to object

• US 20080030711A1
• Filed: 08/03/2007
• Published: 02/07/2008
• Est. Priority Date: 08/03/2006
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: IIZUKA, Nobuo
• Granted Patent: US 7,724,353 B2
• Time in Patent Office: Days
• US Class Current: 356/4.03
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves

Abstract

A method for calculating a distance to an object is provided. In this method, whether luminances received by at least one light receiving elements of a plurality of light receiving elements are equal to or higher than a predetermined value is determined. When luminances received by at least one light receiving elements are equal to or higher than a predetermined value, whether the luminances change in a time-series manner or not is determined. When the luminances change in a time-series manner, information is acquired from the time-series change. Then, a size of a light receiving region is detected based on a ratio of a light receiving element having received luminance with a predetermined value or more to the plurality of light receiving element. Based on the size of the light receiving region and the acquired information, the distance to the object is calculated.

Claims

1. A method, comprising the steps of:

determining whether luminances received by at least one light receiving elements of a plurality of light receiving elements are equal to or higher than a predetermined value;

determining whether the luminances change in a time-series manner or not when luminances received by at least one light receiving elements are equal to or higher than a predetermined value;

acquiring information from the time-series change when the luminances change in a time-series manner;

detecting a size of a light receiving region based on a ratio of a light receiving element having received luminance with a predetermined value or more to the plurality of light receiving elements; and

calculating a distance to an object based on the size of the light receiving region and the acquired information.

2. The method according to claim 1, further comprising the steps of:

determining a shape of the light receiving region, wherein the distance to the object is calculated based on the size of the light receiving region, the acquired information, and the shape of the light receiving region.

3. The method according to claim 1, further comprising the steps of:

controlling imaging operation-related processings based on the calculated distance.

4. The method according to claim 3, wherein the imaging operation-related processings include processings of reproduction or storage of the acquired information based on the calculated distance.

5. The method according to claim 3, wherein the imaging operation-related processings include a processing for displaying imaging-related auxiliary information based on the calculated distance.

6. The method according to claim 3, wherein the imaging operation-related processings include a processing for controlling a focusing section based on the calculated distance.

7. The method according to claim 3, wherein the imaging operation-related processings include a processing for processing an imaged image based on the calculated distance.

8. The method according to claim 3, wherein the imaging operation-related processings include a processing for controlling an optical system mechanism based on the calculated distance.

9. The method according to claim 1, further comprising the steps of:

controlling a display mode of the acquired information to a display section.

10. The method according to claim 9, wherein the step of controlling the display mode includes a step of displaying the acquired information with images imaged by a plurality of light receiving elements.

11. The method according to claim 9, wherein the step of controlling the display mode includes a step of displaying the acquired information in association with the image of the object included in the images imaged by a plurality of light receiving elements.

12. An apparatus, comprising:

a light receiving section including a plurality of light receiving elements;

a first determination section to determine whether luminances received by at least one light receiving elements of a plurality of light receiving elements are equal to or higher than a predetermined value;

a second determination section to determine whether the luminances change in a time-series manner or not when luminances received by at least one light receiving elements are equal to or higher than a predetermined value;

an acquisition section to acquire information from the time-series change when the luminances change in a time-series manner;

a detection section to detect a size of a light receiving region based on a ratio of a light receiving element having received luminance with a predetermined value or more to the plurality of light receiving elements;

a calculation section to calculate a distance to an object based on the size of the light receiving region and the acquired information.

13. A program product causes a computer to function as:

a first determination section to determine whether luminances received by at least one light receiving elements of a plurality of light receiving elements are equal to or higher than a predetermined value;

a second determination section to determine whether the luminances change in a time-series manner or not when luminances received by at least one light receiving elements are equal to or higher than a predetermined value;

an acquisition section to acquire information from the time-series change when the luminances change in a time-series manner;

a detection section to detect a size of a light receiving region based on a ratio of a light receiving element having received luminance with a predetermined value or more to the plurality of light receiving elements;

a calculation section to calculate a distance to an object based on the size of the light receiving region and the acquired information.

14. A system comprising:

a light source including;

a modulation section to modulate size-related information to a time-series luminance change; and

a luminance section emitting light with luminance modulated by this modulation section, and

a light receiving apparatus including;

a light receiving section in which a plurality of light receiving elements are arranged regularly and that receives light from the light source;

a demodulation section to demodulate a luminance change of the light received by this light receiving section to the size-related information;

a detection section to detect a size of a light receiving region based on a ratio of a light receiving element having received the light to the plurality of light receiving elements; and

a measurement section to measure, based on the size of the region detected by the detection section and the size-related information demodulated by the demodulation section, a distance between the light source and a position of the light receiving apparatus.

15. An apparatus, comprising:

a modulation section to modulate information for an area having luminance with a predetermined value or more to time-series luminance change; and

a luminance section that emits light with luminance modulated by this modulation section.