US 7,309,855 B2Granted

Reflective encoder with light shield and electronic device using such reflective encoder

AssigneeSharp Kabushiki Kaisha

InventorsKohji Nagasaka, Kohichi Shichi, Masato Sasaki

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Abstract

A reflection encoder is disclosed having a light emitting element in a light receiving element that are separated by a light shielding body that prevents unwanted light from entering the light receiving element. In variations of the invention, the light shielding body may be integrally formed with a mold resin portion that holds the light emitting element and light receiving element, formed by a sheet or plate, or formed using an opaque liquid resin that is poured between transparent resin bodies that encapsulate the light emitter and receiver. In operation, light radiated from the light emitting element is reflected by a code wheel and then received by a light receiving element. Other variations include varying the height at which the light receiving and detecting elements are disposed relative to the code wheel and tilting these elements towards each other so as to increase light efficiency.

Claims1

Dependent claims

A reflective encoder comprising:

a light emitting portion having a light emitting element capable of irradiating light and a light emitting side transparent resin body for covering and protecting the light emitting element,
a light detecting portion having a light receiving element for detecting light that is irradiated horn the light emitting element and that is reflected by a reflecting region of a code wheel, and a light receiving side transparent resin body for covering and protecting the light receiving element, and
a light shielding body arranged between the light emitting side transparent resin body and the light receiving side transparent resin body for separating the light emitting portion and the light detecting portion,
wherein the light receiving element has a light detecting region and a signal processing circuit, the light detecting region is arranged away from the center of the reflective encoder and the signal processing circuit is arranged toward the center of the reflective encoder.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 11/181,832Filed 15 Jul 2005
Priority: JP 2004-21749526 Jul 2004
Published: US 2006/0016970 A126 Jan 2006
Granted: 18 Dec 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H10F 55/25
Wherein the electric light source controls the radiation-sensitive semiconductor devices, e.g. optocouplers: wherein the radiation-sensitive…
G01D 5/305
The beams of light being detected by photocells: controlling the movement of a following part
G01D 5/34
With attenuation or whole or partial obturation of beams of light: the beams of light being detected by photocells
H10F 77/407
Optical elements or arrangements: indirectly associated with the devices