Arrangement for reading an information carrier

• US 7,505,391 B2
• Filed: 12/03/2003
• Issued: 03/17/2009
• Est. Priority Date: 12/20/2002
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Bakx, Johannus Leopoldus
• Primary Examiner(s): Pwu; Jeffrey
• Assistant Examiner(s): Ali; Farhad
• Application Number:
  US10/537,128
• Publication Number:
  US 20060044989A1
• Time in Patent Office: 1,931 Days
• Field of Search: 709/224, 702/188, 369/124.01, 379/398, 379/124.12
• US Class Current: 369/124.12
• CPC Class Codes: G11B 20/00 Signal processing not specific to the method of recording or reproducing; Circuits therefor
• 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

Abstract

Disclosed is an arrangement for reading an information carrier, comprising a read head for scanning the information carrier along a scanning path and thereby generating one or more electrical signals in response to a pattern recorded along the scanning path; a signal processing unit for processing the one or more electrical signals; electrical conductors for conveying the one or more electrical signals to the signal processing unit; characterized in that the arrangement further comprises controllable termination means for terminating at least one electrical conductor with a selectable impedance, the controllable termination means comprising at least two impedances and selecting means for selecting an impedance to terminate the at least one electrical conductor. The controllable termination means can select one of the at least two impedances. This makes the arrangement according to the invention capable of tuning to varying circumstances. If for certain circumstances a high impedance is needed, then a high impedance is selected. The varying circumstances can, for instance, be the speed at which the information carrier is rotated or the type of read head that is used.

Claims

1. An arrangement for reading an information carrier, said arrangement comprising:

a read head for scanning the information carrier along a scanning path and thereby generating one or more electrical signals in response to a pattern recorded along the scanning path;

a signal processing unit for processing the one or more electrical signals; and

electrical conductors for conveying the one or more electrical signals to the signal processing unit,

wherein the arrangement further comprises controllable termination means for terminating at least one electrical conductor with a selectable impedance, the controllable termination means comprising at least two impedances and selecting means for selecting an impedance to terminate the at least one electrical conductor,

wherein the read head performs the scanning by transmitting a radiation beam to the information carrier and receiving a reflected radiation beam from the information carrier,

wherein the arrangement further comprises measuring means for measuring the reflectance of the radiation beam,

and wherein the controllable termination means selects an impedance dependent on the measured reflectance of the radiation beam.

2. The arrangement as claimed in claim 1, characterized in that the signal processing unit comprises the controllable termination means.

3. The arrangement as claimed in claim 1, characterized in that the selectable impedance comprises a characteristic impedance of the electrical conductors.

4. The arrangement as claimed in claim 1, characterized in that the controllable termination means is able to terminate two or more electrical conductors with different selectable impedances.

5. The arrangement as claimed in claim 3, characterized in that the controllable termination means selects the characteristic impedance when reading the information carrier at a relatively high speed, and selects a higher impedance when reading the information carrier at a relatively low speed.

6. The arrangement as claimed in claim 1, characterized in that one or more of the electrical signals are current outputs and in that the selectable impedance functions as a current to voltage converter.

7. An arrangement for reading an information carrier, said arrangement comprising:

a read head for scanning the information carrier along a scanning path and thereby generating one or more electrical signals in response to a pattern recorded along the scanning path;

a signal processing unit for processing the one or more electrical signals; and

electrical conductors for conveying the one or more electrical signals to the signal processing unit,

wherein the arrangement further comprises controllable termination means for terminating at least one electrical conductor with a selectable impedance, the controllable termination means comprising at least two impedances and selecting means for selecting an impedance to terminate the at least one electrical conductor,

characterized in that at least one electrical conductor is terminated with a selectable impedance which is selected by optimizing one or more parameters of the electrical signal conveyed by the at least one electrical conductor.

8. The arrangement as claimed in claim 7, characterized in that the one or more parameters comprise jitter of one or more electrical signals.

9. The arrangement as claimed in claim 7, characterized in that the one or more parameters comprise an amplitude of one or more electrical signals.

10. The arrangement as claimed in claim 7, characterized in that the one or more parameters comprise an overshoot of one or more electrical signals.