Subject state detecting apparatus for detecting dynamically moving subject

• US 6,649,904 B2
• Filed: 06/12/2002
• Issued: 11/18/2003
• Est. Priority Date: 12/25/2001
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hashimoto, Manabu, Hayashi, Kentaro, Sumi, Kazuhiko
• Primary Examiner(s): Pyo, Kevin
• Assistant Examiner(s): Sohn, Seung C.
• Application Number:
  US10/166,694
• Publication Number:
  US 20030116698A1
• Time in Patent Office: 524 Days
• Field of Search: 250/221, 250/559.38, 250/559.07, 250/559.08, 250/559.22, 250/201.6, 356/3.01, 356/3.02, 356/3.04, 356/3.06, 356/623, 356/138, 356/614, 356/622
• US Class Current: 250/221
• CPC Class Codes: B60R 21/01538 for image processing, e.g. cameras or sensor arrays
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 21/01552 detecting position of specific human body parts, e.g. face, eyes or hands

Abstract

A subject-state detecting apparatus has an active distance measuring sensor including projectors for targeting measurement regions independently, and a photodetector for detecting reflection light reflected from a subject that receives light projected by the light projectors. A measurement parameter decision section decides in advance a body parameter to be measured. In response to the parameter, a distance measuring sensor setting section sets a measurement region of the active distance measuring sensor and an additional distance measuring sensor. A state decision section decides state of the subject from the outputs of these sensors.

Claims

1. A subject-state detecting apparatus comprising:

a distance measuring section that has an active distance measuring sensor including a plurality of light projectors controlled independently in targeting respective measurement regions, and a photodetector for detecting reflection light reflected from a subject that receives light projected by said plurality of light projectors;

a measurement parameter decision section for selecting, body parameters measured by said distance measuring section based on states of the subject and surroundings of the subject;

a distance measuring sensor setting section for setting a measurement regions of said active distance measuring sensor, in response to the body parameters selected; and

a state decision section for analyzing a detection output of said active distance measuring sensor from the measurement regions, and for determining a state of the subject with reference to prescribed judgment criteria.

2. The subject-state detecting apparatus according to claim 1, further comprising a measuring timing control section for generating a timing control signal in response to a setting of said active distance measuring sensor, obtained by said distance measuring sensor setting section, and for controlling said distance measuring section such that said active distance measuring sensor illuminates the subject in response to the timing control signal.

3. The subject-state detecting apparatus according to claim 1, further comprising a time direction measurement section for triggering said measurement parameter decision section such that said distance measuring section iterates a measuring operation already carried out once, a predetermined number of times in a time direction, wherein said state decision section stores time series measurement data captured in the measuring operation iterated, and carries out smoothing processing and deviation value processing of stored measurement data to obtain a decision result.

4. The subject-state detecting apparatus according to claim 2, wherein said subject-state detecting apparatus is mounted on a vehicle, and further comprising:

an additional sensor; and

a distance measuring sensor drive decision section for making a decision as to whether said subject-state detecting apparatus is to be driven in response to a detection output of said additional sensor mounted on said vehicle, and for activating said measurement parameter decision section to start operation of said subject-state detecting apparatus.

5. The subject-state detecting apparatus according to claim 4, wherein, when said additional sensor is a vehicle speed sensor, said distance measuring sensor drive decision section commands said measuring timing control section to generate the timing control signal corresponding to a vehicle speed in response to a detection output of said vehicle speed sensor.

6. The subject-state detecting apparatus according to claim 1, further comprising a sensor usage selection section for a user to specify whether said subject-state detecting apparatus is to be driven.

7. The subject-state detecting apparatus according to claim 1, further comprising a detection result display section for displaying a decision result supplied from said state decision section, wherein said state decision section supplies said detection result display section with information including a comment and a display drawing said state decision section produces by evaluating the decision result with reference to predetermined evaluation criteria, with the information contained in the decision result.

8. The subject-state detecting apparatus according to claim 1, further comprising a state instruction/registration section for updating and registering the judgment criteria said state decision section uses for deciding the subject state in accordance with a need of a user.

9. The subject-state detecting apparatus according to claim 1, wherein said light projectors comprise a surface emitting laser for outputting a plurality of laser beams, and a lens system for collimating and spreading the laser beams, and wherein said photodetector is placed next to the lens system.

10. The subject-state detecting apparatus according to claim 1, wherein said light projectors comprise a laser diode (LD) module consisting of a plurality of LDs placed in a line, and a semicircular cylindrical lens for spreading light of the laser beams from said LD module, and wherein said photodetector is disposed next to the LD module.

11. The subject-state detecting apparatus according to claim 1, further comprising an additional distance measuring sensor, wherein said distance measuring sensor setting section sets said additional distance measuring sensor, and said state decision section analyzes a detection output of said additional distance measuring sensor to determine the state of the subject.