Optical Fiber Sensor

• US 20080310792A1
• Filed: 03/07/2006
• Published: 12/18/2008
• Est. Priority Date: 03/14/2005
• Status: Abandoned Application

• Current Assignee: DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Iyoda, Motomi, Takahashi, Hiroyuki, Miyata, Yujiro, Kachu, Ryotaro, Ohtaka, Koji
• Application Number:
  US11/886,186
• Publication Number:
  US 20080310792A1
• Time in Patent Office: Days
• US Class Current: 385/13
• CPC Class Codes: G01D 5/353 influencing the transmission properties of an optical fibre
• CPC Class Codes: G01L 1/242 the material being an optical fibre

Abstract

An optical fiber sensor (8) has an optical fiber (2) and, a light emitting member (3) connected to a first end (20) of the optical fiber (2), a light receiving member (4) connected to a second end (21) of the optical fiber (2). The light emitting member (3) has a light emitting portion (300) through which light is radiated to the first end (20) of the optical fiber (2). The light receiving member (4) has a light receiving portion (400) for receiving light radiated from the second end (21) of the optical fiber (2). The light emitting portion (300) is smaller than a sectional area of a core portion (25) of the optical fiber (2).

Claims

1. An optical fiber sensor comprising:

an optical fiber having a core portion and a clad portion covering the core portion;

a light emitting member connected to a first end of the optical fiber, the light emitting member having a light emitting portion for emitting light to the first end of the optical fiber; and

a light receiving member connected to a second end of the optical fiber, the light receiving member having a light receiving portion for receiving light radiated from the second end of the optical fiber, wherein the light emitting portion is smaller than a sectional area of the core portion,

the light emitting portion is disposed such that a center thereof is aligned with an axis of the optical fiber, and

the light receiving portion is disposed such that a center thereof is aligned with the axis of the optical fiber.

2. The optical fiber sensor according to claim 1, wherein the light receiving portion is larger than the sectional area of the core portion.

3. The optical fiber sensor according to claim 1, wherein the light emitting portion has an outer diameter that is smaller than a diameter of the core portion.

4. The optical fiber sensor according to claim 1, wherein the light emitting portion is disposed to oppose an end surface of the first end of the optical fiber so that a diameter of the light radiated to the first end of the optical fiber is smaller than a diameter of the core portion at the end surface of the optical fiber.

5. The optical fiber sensor according to claim 1, wherein the light emitting portion is embedded in the first end of the optical fiber.

6. The optical fiber sensor according to claim 1, further comprising a calculating part connected to the light emitting member and the light receiving member, wherein the calculating part detects a stress applied to the optical fiber based on a characteristic of the light emitted from the light emitting portion and a characteristic of the light received in the light receiving portion.

7. A collision detecting sensor for a vehicle, having the optical fiber sensor as in claim 1, wherein the optical fiber sensor detects a collision of a pedestrian to the vehicle.