Detection device for detecting conditions at a target position

• US 7,605,909 B2
• Filed: 04/18/2006
• Issued: 10/20/2009
• Est. Priority Date: 04/28/2005
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamaguchi, Atsushi, Yamada, Masato, Suzuki, Yoshihisa, Ichiura, Shuichi
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Brainard; Timothy A
• Application Number:
  US11/405,450
• Publication Number:
  US 20060265147A1
• Time in Patent Office: 1,281 Days
• Field of Search: 356/5.11, 356/3.09, 356/5.01
• US Class Current: 356/5.01
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

An object of the present invention is to provide a detection device which does not cause the false detection by receiving laser light from an oncoming car.

The pulse laser light modulated with a modulation pattern set every target position is irradiated at the target position from a laser irradiation portion. DSP (Digital Signal Processor) decides that there is an obstacle at the target position only when the modulation pattern of the pulse laser light emitted from the laser emitting portion matches with the modulation pattern of the pulse laser light received by the laser receiving portion. It is suppressed that the detection device misdetects the conditions of the target position when receiving laser light from an oncoming car or the like because modulation pattern of laser light from own does not match with modulation pattern of laser light from the oncoming car or the like.

Claims

1. A detection device for detecting conditions at a target position by irradiating a laser light to the target position, comprising:

irradiation means for irradiating the laser light having a unique modulation pattern to the target position;

light reception means for receiving a laser light from the target position;

modulation means for modulating the laser light irradiated from the irradiation means, wherein a modulation pattern of the laser light irradiated from the irradiation means is chosen among a plurality of different modulation pattern;

distinction means for distinguishing whether the modulation pattern of the laser light irradiated from the irradiation means matches with a modulation pattern of the laser light received by the light reception means, whereby identifying the laser light received by the light reception means is the laser light that is irradiated from the irradiation means and reflected by an object at the target position when the modulation pattern of the laser light received by the light reception means is the unique modulation pattern of the light irradiated to the target position;

detection means for detecting conditions of the target position based on a light reception state in the light reception means when the modulation pattern of the laser light irradiated from the irradiation means matches with the modulation pattern of the laser light received by the light reception means; and

means for adjusting an irradiation direction of the laser light from the irradiation means so as to change the target position irradiated by the laser light,

wherein the modulation means sets a modulation pattern of the laser light for every target position,

wherein the detection device is mounted on a moving vehicle such that conditions of a moving object at the target position are detected, and

wherein the modulation means modulates the laser light such that the laser light irradiated to the target position is distinguishable with a state of a group of laser pulses and changes the state of the group of the laser pulses every shift of the target position.

2. The detection device according to claim 1, wherein

the modulation means changes the number of times of irradiation of the laser light every shift of the target position.

3. The detection device according to claim 1, wherein

the modulation means changes a period of irradiation of the laser light every shift of the target position.

4. The detection device according to claim 1, wherein

the modulation means irradiates multiple times the laser light at the target position and changes irradiation strength of the laser light of each time, according to a modulation rule, every shift of the target position.

5. A detection device for detecting conditions at a target position by irradiating a laser light to the target position, comprising:

an irradiation portion for irradiating the laser light having a unique modulation pattern to the target position;

a light reception portion for receiving a laser light from the target position;

a modulation circuit for modulating the laser light irradiated from the irradiation portion, wherein a modulation pattern of the laser light irradiated from the irradiation portion is chosen among a plurality of different modulation patterns;

a distinction circuit for distinguishing whether a modulation pattern of the laser light irradiated from the irradiation portion matches with a modulation pattern of the laser light received by the light reception portion, whereby identifying the laser light received by the light reception portion is the laser light that is irradiated from the irradiation portion and reflected by an object at the target position when the modulation pattern of the laser light received by the light reception portion is the unique modulation pattern of the light irradiated to the target position;

a detection circuit for detecting conditions of the target position based on a light reception state in the light reception portion when the modulation pattern of the laser light irradiated from the irradiation portion matches with the modulation pattern of the laser light received by the light reception portion; and

an actuator for adjusting an irradiation direction of the laser light from the irradiation means so as to change the target position irradiated by the laser light; and

an actuator drive circuit for driving the actuator;

wherein the modulation circuit sets a modulation pattern of the laser light for every target position,

wherein the detection device is mounted on a moving vehicle such that conditions of a moving object at the target position are detected, and

wherein the modulation circuit modulates the laser light such that the laser light irradiated to the target position is distinguishable with a state of a group of laser pulses and changes the state of the group of the laser pulses every shift of the target position.

6. The detection device according to claim 5, wherein

the modulation circuit changes the number of times of irradiation of the laser light every shift of the target position.

7. The detection device according to claim 5, wherein

the modulation circuit changes a period of irradiation of the laser light every shift of the target position.

8. The detection device according to claim 5, wherein

the modulation circuit irradiates multiple times the laser light at the target position and changes irradiation strength of the laser light of each time, according to a modulation rule, every shift of the target position.