Mirror and angle detection apparatus

• US 20060029376A1
• Filed: 08/03/2005
• Published: 02/09/2006
• Est. Priority Date: 08/05/2004
• Status: Active Grant

• Current Assignee: Murakami Corporation
• Original Assignee: Murakami Corporation
• Inventors: Sato, Hidenori, Yamada, Ayako
• Granted Patent: US 7,270,432 B2
• Time in Patent Office: Days
• US Class Current: 396/20
• CPC Class Codes: B60R 1/072 for adjusting the mirror relative to its housing

Abstract

A mirror (18) having a specular surface changeable in orientation using an actuator (16) is provided with an angle detection capability at reduced cost. A plate pivot (10) can change its orientation together with the specular surface so as to orient in a direction in which the specular surface is orienting. A slide block (20) is stressed toward the plate pivot (10) so that rotation of the plate pivot (10) causes the slide block (20) to move in a direction substantially perpendicular to the specular surface by an amount proportional to an amount of the rotation of the plate pivot (10). A magnet (26) moves in the direction of movement of the slide block (20) by an amount proportional to an amount of the movement of the slide block (20), and a magnetism sensing element (202) detects magnetism derived from the magnet (26) and outputs a signal corresponding to the amount of movement of the magnet (26).

Claims

1. A mirror having a specular surface changeable in orientation, the mirror comprising:

an actuator adapted to rotate the specular surface about an axis parallel with the specular surface to change the orientation of the specular surface;

an interlocking member adapted to change orientation thereof together with the specular surface so as to orient in a direction in which the specular surface is orienting;

a slide block stressed toward the interlocking member so that rotation of the interlocking member causes the slide block to move in a direction of movement substantially perpendicular to the specular surface by an amount proportional to an amount of the rotation of the interlocking member;

a movable member adapted to move in the direction of movement of the slide block by an amount proportional to an amount of the movement of the slide block; and

a moving amount detection unit adapted to detect the amount of movement of the movable member.

2. A mirror according to claim 1, wherein the interlocking member comprises a plate pivot adapted to rotate about the axis parallel with the specular surface so as to tilt the specular surface.

3. A mirror according to claim 1, further comprising:

a first elastic member provided between the movable member and the slide block to stress the slide block toward the interlocking member; and

a second elastic member adapted to stress the movable member toward the first elastic member,

wherein movement of the slide block causes the movable member to move in the direction of the movement of the slide block by an amount smaller than the amount of the movement of the slide block.

4. A mirror according to claim 2, further comprising:

a first elastic member provided between the movable member and the slide block to stress the slide block toward the interlocking member; and

a second elastic member adapted to stress the movable member toward the first elastic member,

wherein movement of the slide block causes the movable member to move in the direction of the movement of the slide block by an amount smaller than the amount of the movement of the slide block.

5. A mirror according to claim 1, wherein the movable member comprises a magnet;

and

wherein the moving amount detection unit comprises a magnetism sensing element adapted to detect magnetism derived from the magnet to output a signal corresponding to the amount of the movement of the movable member.

6. A mirror according to claim 5, further comprising a circuit board opposed to the interlocking member with the slide block and the magnet disposed between the circuit board and the interlocking member,

wherein the magnetism sensing element is mounted on the circuit board.

7. A mirror according to claim 5, wherein the magnet has a length shorter in a direction substantially perpendicular to the specular surface than a maximum distance covered by the movement of the slide block corresponding to a maximum range of rotation of the specular surface.

8. A mirror according to claim 6, wherein the magnet has a length shorter in a direction substantially perpendicular to the specular surface than a maximum distance covered by the movement of the slide block corresponding to a maximum range of rotation of the specular surface.

9. A mirror according to claim 5, wherein the magnetism sensing element comprises a Hall element applying a Hall voltage between first and second voltage output terminals;

and

wherein the mirror further comprises;

first and second temperature-compensating elements having a resistance decreasing or increasing according to increase in temperature, the first and second temperature-compensating elements connected to the first and second voltage output terminals respectively; and

an operational amplifier adapted to amplify the Hall voltage received from the Hall element through the first and second temperature-compensating elements.

10. A mirror according to claim 6, wherein the magnetism sensing element comprises a Hall element applying a Hall voltage between first and second voltage output terminals;

and

wherein the mirror further comprises;

first and second temperature-compensating elements having a resistance decreasing or increasing according to increase in temperature, the first and second temperature-compensating elements connected to the first and second voltage output terminals respectively; and

an operational amplifier adapted to amplify the Hall voltage received from the Hall element through the first and second temperature-compensating elements.

11. An angle detection apparatus for detecting an angle of a specular surface, comprising:

a slide block stressed toward an interlocking member so that rotation of the interlocking member causes the slide block to move in a direction of movement substantially perpendicular to the specular surface by an amount proportional to an amount of the rotation of the interlocking member adapted to change orientation thereof together with the specular surface so as to orient in a direction in which the specular surface is orienting;

a movable member adapted to move in the direction of movement of the slide block by an amount proportional to an amount of the movement of the slide block; and

a moving amount detection unit adapted to detect the amount of movement of the movable member.