OPTICAL INFORMATION RECORDING MEDIUM AND RECORDING AND REPRODUCING METHOD THEREFOR

Title:

OPTICAL INFORMATION RECORDING MEDIUM AND RECORDING AND REPRODUCING METHOD THEREFOR

Document Type and Number:

Japanese Patent JPH0512717

Kind Code:

A

Abstract:

PURPOSE: To increase the quantity of the light reflected from an optical card and to improve S/N.

CONSTITUTION: The direction A of the optical axis of the double refractions in the transparent protective layer of the optical card 1 is set in the direction parallel or perpendicular to the long side 1a of the optical card 1. The optical card 1 is irradiated via a collimator lens 32, a polarization beam splitter 25 and an objective lens 26 with the LED light outputted from an LED 31. The LED light reflected by the optical card 1 i made incident on a photodetector 35 via the objective lens 26, the polarization beam splitter 25, a half prism 33, and a condenser lens 34.

Inventors:

OTSUKI SHINYA
TSUBOI KAZUO
TAKAHASHI TATSUMI

Application Number:

JP18549091A

Publication Date:

January 22, 1993

Filing Date:

June 28, 1991

Export Citation:

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Assignee:

OMRON TATEISI ELECTRONICS CO
DAINIPPON PRINTING CO LTD

International Classes:

G11B7/00; G11B7/0033; G11B7/135; G11B7/24; (IPC1-7): G11B7/00; G11B7/135; G11B7/24

Attorney, Agent or Firm:

Yoshio Inamoto

Next Patent: JPS512718