Proximity detector

• US 20070127039A1
• Filed: 11/12/2004
• Published: 06/07/2007
• Est. Priority Date: 11/19/2003
• Status: Active Grant

• Current Assignee: New Index AS (Seiko Group)
• Original Assignee: New Index AS (Seiko Group)
• Inventors: Njølstad, Tormod
• Granted Patent: US 7,339,684 B2
• Time in Patent Office: Days
• US Class Current: 356/624
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G01C 3/06 Use of electric means to obtain final indication
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver

Abstract

Apparatus for detecting proximity between a first object (target object) and a second object (reference object), comprising a light source and a light detector adapted to receive resulting back-scattered light from the reference object when illuminated from the light source, whereby the intensity of back-scattered light to the light detector is utilized as a measure of said proximity. The target object comprises an optical device having a focal plane and being adapted to be illuminated by the light source. The axes of the light rays from the light source and the back-scattering to the light detector have mutually closely adjacent and substantially parallel or coincident portions. Said proximity corresponds to a distance (relative position) between the target object and the reference object wherein the reference object is located substantially at the focal plane.

Claims

1. Apparatus for detecting proximity between a first object (target object) and a second object (reference object), comprising a light source (1) and a light detector (3) adapted to receive resulting back-scattered light from the reference object when illuminated from the light source (1), whereby the intensity of back-scattered light to the light detector (3) is utilized as a measure of said proximity, characterized in that the target object (2) comprises an optical device (4) having a focal plane (7) and being adapted to be illuminated by the light source (1), that the axes of the light rays from the light source (1) and the back-scattering to the light detector (3) have mutually closely adjacent and substantially parallel or coincident portions, and

that said proximity corresponds to a spacing (relative position) between the target object (2) and the reference object (6,8) wherein the reference object is located substantially at the focal plane.

2. Apparatus according to claim 1, wherein the light source (1) and/or the light detector (3) are/is located on the target object (2).

3. Apparatus according to claim 1, wherein said axes outside said portions have deviating directions, such as by using mirrors, optical fibres or light conductors.

4. Apparatus according to claim 1, wherein the light source (1) is adapted to emit modulated or possibly pulsed light, and the light detector (3) is synchronized with such modulation or pulsing.

5. Apparatus according to claim 1, wherein the light detector comprises a camera (3).

6. Apparatus according to claim 1, wherein the optical device (4) has at least two focal planes for determination of said proximity in at least two relative positions of the target object (2) and the reference object (6,8).

7. Apparatus according to claim 1, wherein the intensity of back-scattered light to the light detector (3) is compared with a predetermined and preferably adjustable level, for detection of said proximity.

8. Apparatus according to claim 1, wherein the light source (1) and the light detector (3) are located separately in relation to one another.

9. Apparatus according to claim 1, wherein the light source consists of a data projector (FIG. 2).

10. Drawing, writing and/or pointing tool for data presentation, computer-supported work or interactive operations with a computer, wherein an apparatus according to claim 1 is incorporated in the tool.

11. Apparatus for detecting proximity between a first object (target object) and a second object (reference object), comprising a light source (1) and a receiver for resulting back-scattered light from the reference object when illuminated from the light source (1), whereby the intensity of back-scattered light to the receiver is utilized as a measure of said proximity,

characterized in

that the target object (2) comprises an optical device (4) having a focal plane (7) and being adapted to be illuminated by the light source (1),

that the axes of the light rays from the light source (1) and back-scattering to the receiver have mutually closely adjacent and substantially parallel or coincident portions, that said proximity corresponds to a distance (relative position) between the target object (2) and the reference object (6,8) wherein the reference object is located substantially at the focal plane, and that the receiver is adapted to cooperate with an eye belonging to a user of the apparatus.

12. Apparatus according to claim 11, wherein the light source consists of a data projector.