Optical scanning-type touch panel

• US 20010055006A1
• Filed: 06/07/2001
• Published: 12/27/2001
• Est. Priority Date: 02/24/1999
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Iwamoto, Yasuhide, Sano, Satoshi, Nakazawa, Fumihiko, Yamaguchi, Nobuyasu
• Granted Patent: US 7,522,156 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G06F 3/0423 using sweeping light beams, e.g. using rotating or vibrating mirror

Abstract

Laser light emitted by a light emitting element is made parallel light by a collimation lens, passes through an aperture of an aperture mirror, and is then angularly scanned in a plane substantially parallel to a display screen by rotation of a polygon mirror and projected onto a recurrence reflection sheet. Then, after the reflected light from the recurrence reflection sheet is reflected by the polygon mirror and aperture mirror, the light is focused by a condenser lens to enter a light receiving element. The aperture mirror has an asymmetrical shape in the scanning direction and/or the vertical direction about the optical axis, according to a scanning surface opening width of the polygon mirror.

Claims

1. An optical scanning-type touch panel comprising:

an optical scanning unit for angularly scanning light in a plane substantially parallel to a predetermined region;

a deflecting unit for deflecting scanning light of said optical scanning unit; and

a light receiving unit for receiving the deflected scanning light, for detecting a scanning light cut-off position, which is produced in said predetermined region by an indicator, based on a light receiving output of said light receiving unit that corresponds to a scanning angle, said optical scanning-type touch panel being characterized in that said deflecting unit has an asymmetrical shape about an optical axis.

2. The optical scanning-type touch panel as set forth in claim

wherein the shape of said deflecting unit is asymmetrical in a scanning direction.

3. The optical scanning-type touch panel as set forth in claim

wherein the shape of said deflecting unit is asymmetrical in a height direction.

4. The optical scanning-type touch panel as set forth in

claim 3

,

wherein a height of said deflecting unit is substantially equal to a height of said optical scanning unit.

5. The optical scanning-type touch panel as set forth in

claim 4

,

wherein said predetermined region has a rectangular shape, and a width of said deflecting unit is substantially equal to a scanning surface opening width of said optical scanning unit in scanning a diagonal section of said predetermined region with light.

6. An optical scanning-type touch panel comprising:

an optical scanning unit for angularly scanning light in a plane substantially parallel to a predetermined region;

a deflecting unit for deflecting scanning light of said optical scanning unit; and

a light receiving unit for receiving the deflected scanning light, for detecting a scanning light cut-off position, which is produced in said predetermined region by an indicator, based on a light receiving output of said light receiving unit that corresponds to a scanning angle, said optical scanning-type touch panel being characterized by satisfying a condition

d/2+w<

D tan δ

where D is a distance from said optical scanning unit to said deflecting unit, w is a width on said deflecting unit from a path of said scanning light to an end on said predetermined region side , d is a beam width of said scanning light , and δ

is a scanning start angle.

7. An optical scanning-type touch panel comprising:

a light retro-reflector provided outside a predetermined region;

an optical scanning unit for angularly scanning light in a plane substantially parallel to said predetermined region; and

a light receiving unit for receiving reflected light of scanning light of said optical scanning unit from said light retro-reflector, for detecting a scanning light cut-off position, which is produced in said predetermined region by an indicator, based on a light receiving output of said light receiving unit that corresponds to a scanning angle, said optical scanning-type touch panel being characterized in that said optical scanning unit is provided with a protective film having a maximum reflectance at an angle of incidence corresponding to a scanning angle at which a quantity of said reflected light is minimum.