Slim optical pickup

• US 20050094534A1
• Filed: 10/12/2004
• Published: 05/05/2005
• Est. Priority Date: 11/04/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Choi, Hyung, You, Jae-ho, Yoon, Eung-yeoul, Hwang, Woong-lin
• Granted Patent: US 7,471,595 B2
• Time in Patent Office: Days
• US Class Current: 369/112.01
• CPC Class Codes: G11B 7/08576 Swinging-arm positioners
• CPC Class Codes: G11B 7/12 Heads, e.g. forming of the optical beam spot or modulation of the optical beam disposition or mounting of head elements within housing or with provision for moving of light source, optical beam or detector, irrelevant to the transducing method G11B7/08 ; modulating lasers H01S3/10; controlling the intensity, colour, phase, polarisation or direction of light beams arriving from an independent light source, e.g. switching gating or modulating G02F1/00
• CPC Class Codes: G11B 7/123 Integrated head arrangements, e.g. with source and detectors mounted on the same substrate
• CPC Class Codes: G11B 7/1263 Power control during transducing, e.g. by monitoring
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: G11B 7/131 Arrangement of detectors in a multiple array
• CPC Class Codes: G11B 7/22 Apparatus or processes for the manufacture of optical heads, e.g. assembly

Abstract

A slim optical pickup in which a leaf spring is combined with an upper surface of a semiconductor substrate, which is a silicon optical bench (SiOB) monolithically manufactured with a photodetector. The slim optical pickup has a substrate including a light source for generating a light beam, an optical element to irradiate light to an optical disc, a photodetector for receiving a light beam reflected by the optical disc, and a plurality of first bonding pads; a heat sink attached to the surface of the substrate; and a supporting means having a plurality of second bonding pads formed on an inner side of an array of the plurality of the first bonding pads on the substrate.

Claims

1. A slim optical pickup for recording and reproducing data to and from an optical disc, the slim optical pickup comprising:

a substrate including a light source that generates light, an optical device that irradiates light onto the optical disc, a photodetector that receives a light beam reflected by the optical disc, and a plurality of bonding pads;

a heat sink attached to a surface of the substrate; and

a supporting unit that includes a plurality of second bonding pads and is disposed on an opposite surface of the substrate to which the heat sink is attached.

2. The slim optical pickup of claim 1, wherein the second bonding pads formed on the supporting unit are located at an inner side of the first bonding pads formed on the substrate.

3. The slim optical pickup of claim 2, wherein the second bonding pads formed on the supporting unit are electrically connected to the first bonding pads formed on the substrate by wire bonding.

4. The slim optical pickup of claim 1, wherein the substrate is formed of silicon having a {100} plane.

5. The slim optical pickup of claim 4, wherein the optical device formed on the substrate is a slope mirror formed of silicon having a {111} plane.

6. The slim optical pickup of claim 5, wherein the photodetector includes an eight-partitioned photodetector and a monitoring photodetector.

7. The slim optical pickup of claim 6, further comprising:

a polarizing device disposed facing the photodetector, said polarizing device including first and second reflection surfaces and a polarized beam splitter;

a spacer disposed between the substrate and the polarizing device;

a hologram optical element; and

an objective lens.

8. The slim optical pickup of claim 7, wherein the hologram optical element is formed on said polarizing device.

9. The slim optical pickup of claim 8, further comprising a λ

/4 plate arranged between the polarized beam splitter and the optical disc, wherein λ

is a wavelength of incident light.

10. The slim optical pickup of claim 9, wherein the supporting means comprises a leaf spring.

11. The slim optical pickup of claim 10, wherein the leaf spring includes an opening through which the photodetector can receive a light beam generated from the light source and reflected by the optical disc.

12. The slim optical pickup of claim 11, wherein the spacer further includes a monitoring mirror to reflect light generated from the light source having a radiation angle greater than that of light incident to the slope mirror towards the monitoring photodetector.

13. The slim optical pickup of claim 12, wherein the amount of light received by the monitoring photodetector is converted to an electrical signal for controlling the intensity of the light source.

14. The slim optical pickup of claim 1, wherein the heat sink is located in a direction toward the optical disc.

15. The slim optical pickup of claim 1, wherein the supporting unit has a structure on which a plurality of bonding pads are formed to match the bonding pads formed on the substrate.

16. The slim optical pickup of claim 15, wherein the supporting unit includes a leaf spring, an insulating film formed on the leaf spring, and a plurality of bonding pads formed on the insulating film.

17. The slim optical pickup of claim 16, wherein the bonding pads formed on the supporting unit are electrically connected to the boning pads formed on the substrate by a BGA method.

18. The slim optical pickup of claim 16, wherein an adhesive is applied to a predetermined portion of a contact surface between the substrate and the leaf spring, except for the bonding pads, to thereby bond the substrate and the leaf spring.

19. The slim optical pickup of claim 18, wherein the leaf spring is formed of stainless steel.

20. The slim optical pickup of claim 1, wherein the supporting unit has an opening through which the photodetector receives a light beam generated from the light source and reflected by the optical disc, and the bonding pads formed on the supporting unit are formed on regions in which the opening is not formed.