Optical system for accessing a storage medium

• US 20030090988A1
• Filed: 07/03/2002
• Published: 05/15/2003
• Est. Priority Date: 12/11/2001
• Status: Active Grant

• Current Assignee: Discovision Associates (Pioneer Corporation)
• Original Assignee: Discovision Associates (Pioneer Corporation)
• Inventors: Chen, Darren, Sun, Vincent
• Granted Patent: US 7,050,381 B2
• Time in Patent Office: Days
• US Class Current: 369/112.28
• CPC Class Codes: G11B 2007/0006 adapted for scanning different types of carrier, e.g. CD & DVD
• CPC Class Codes: G11B 7/123 Integrated head arrangements, e.g. with source and detectors mounted on the same substrate
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: G11B 7/1356 Double or multiple prisms, i.e. having two or more prisms in cooperation
• CPC Class Codes: G11B 7/1359 Single prisms

Abstract

An optical system for accessing a storage medium. The system combines two kinds of laser diode, abandons some unnecessary optical elements used in the prior art, and further uses a Penta prism to fold the optical path. Moreover, the optical system uses a CZBO prism to locate the two laser diodes abreast of each other. Thus, the space of the optical system is reduced, and the optical system is more compact.

Claims

1. An optical system for accessing a storage medium, comprising:

a beam splitter selectively transmitting a beam of a first wavelength and reflecting a beam of a second wavelength;

a right-angle prism having a convex surface for constructing the right angle thereof, wherein the right-angle prism receives the beam from the beam splitter and emits a collimated beam toward the storage medium, or redirects a beam from the storage medium to the beam splitter; and

an objective lens for projecting the collimated beam on the storage medium and redirecting the beam from the storage medium to the right-angle prism.

2. An optical system for accessing a storage medium as claimed in claim 1, wherein the convex surface is provided with a spherical convex surface.

3. An optical system for accessing a storage medium as claimed in claim 1, wherein the convex surface is provided with an aspherical convex surface.

4. An optical system for accessing a storage medium comprising:

a CZBO prism for transmitting a beam of first wavelength and a beam of second wavelength by two reflections;

a Penta prism reflecting the beam from the CZBO prism twice and deviating the beam by 90°

, and reflecting the beam from the storage medium and deviating the beam by 90°

;

a right-angle prism including a convex surface for constructing the right angle thereof, wherein the right-angle prism receives the beam from the Penta prism and emits a collimated beam toward the storage medium, or redirects a beam from the storage medium to the Penta prism; and

an objective lens for projecting the collimated beam on the storage medium and redirecting the beam from the storage medium to the right-angle prism.

5. An optical system for accessing a storage medium as claimed in claim 4, wherein the convex surface is provided with a spherical convex surface.

6. An optical system for accessing a storage medium as claimed in claim 4, wherein the convex surface is provided with an aspherical convex surface.

7. An optical system for accessing a storage medium as claimed in claim 4, further comprising two laser diodes, which are positioned abreast by utilizing the CZBO prism and packaged with the CZBO prism.

8. An optical system for accessing a storage medium comprising:

a CZBO prism for transmitting a beam of first wavelength and a beam of second wavelength by two reflections;

a Penta prism having a convex surface for emitting a collimated beam, wherein the Penta prism reflects the beam from the CZBO prism twice and deviating the beam by 90°

, and reflecting the beam from the storage medium and deviating the beam by 90°

; and

an objective lens for projecting the collimated beam on the storage medium and redirecting the beam from the storage medium to the Penta prism.

9. An optical system for accessing a storage medium as claimed in claim 8, wherein the convex surface is provided with a spherical convex surface.

10. An optical system for accessing a storage medium as claimed in claim 8, wherein the convex surface is provided with an aspherical convex surface.

11. An optical system for accessing a storage medium as claimed in claim 8, further comprising two laser diodes, which are positioned abreast by utilizing the CZBO prism and packaged with the CZBO prism.