Title of Invention | " AN OPTICAL DISC REPRODUCING APPARATUS AND METHOD" |
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Abstract | When an optical disk having a plurality of recording layers is loaded, in which layer-number data is recorded on the recording layer nearest to the signal reading plane and layer I.D. data is recorded on each recording layer, a pickup reads the data recorded on each recording layer. A focus error signal is produced by a quartered detector by using return light from the pickup. A focus search drive Circuit generates a focus drive signal. When focalization on a desired recording layer is' established during focus search by the focus search drive circuit, the focus search drive circuit is stopped. |
Full Text | DESCRIPTION (COMPLETE) OCR NOT PREPARE DUE TO PRINT PROBLEM CLAIM: 1. An optical disk reproducing apparatus comprising: a pickup for reading recorded data from an optical disk; focus error signal generating means for generating a focus error signal from light read out by said pickup; focus search means for supplying a focus drive signal to said pickup to perform a focus search; characterized by detector means for detecting a desired recording layer in response to said focus error signal; and control means for stopping the supply of said focus signal in response to a detection signal from said detector means. 2. The optical disk reproducing apparatus as claimed in claim 1, wherein said detector means have: zero-cross detector means for detecting the zero-cross of said focus error signal; and counter means for counting the occurrences of detection of said zero-cross. 3. An optical disk reproducing apparatus as claimed in claim 1 having: designator means for designating a desired recording layer number; comparator means for comparing said layer number designated by said designator means with the occurrences of detection of the zero-cross of said focus error signal during focus search; and control means for stopping the supply of said focus signal when the result of said comparison exhibits coincidence. 4. An optical disk reproducing apparatus as claimed in claim 1 having: storage means for storing the layer number of a layer currently reproduced; first comparator means for comparing a layer number reproduced after a focus jump with said layer number stored in said storage means; second comparator means for performing said focus search when the result of said comparison exhibits non-coincidence and for comparing said layer number stored in said storage means with the occurrences of detection of the zero-cross of the focus error signal; control means for stopping the supply of said focus signal when the result of said comparison by said second comparator means exhibits coincidence. 5. An optical disk reproducing method comprising the steps of: supplying a focus drive signal to said pick up to perform a focus search; in response to a focus error signal, detecting a recording layer number; and stopping the supply of said focus drive signal when the result of the detection coincides with a desired layer number. 6. The optical disk reproducing method as claimed in claim 6, including the step of reproducing layer number data from one of the layers nearest to a signal reading plane of said optical disk to discriminate the type of said optical disk when said reproducing apparatus is activated. 7. The optical disk reproducing method as claimed in claim 6, wherein said step of detecting a recording layer number includes the steps of: detecting the zero-cross of said focus error signal; and counting the occurrences of detection of said zero-cross. 8. An optical disk reproducing method as claimed in claim 6 including the steps of: designating a desired recording layer number; supplying a focus drive signal to a pickup to perform a focus search; comparing the designated layer number with the occurrences of detection of the zero-cross of a focus error signal; and stopping the supply of said focus drive signal when the result of the comparison exhibits coincidence. 9. An optical disk reproducing method as claimed in claim 6 including the steps of: storing a layer number of a layer currently reproduced; comparing a layer number reproduced after a focus jump with the stored layer number; supplying a focus drive signal to a pickup to perform a focus jump when the result of the comparison exhibits non-coincidence; comparing the stored layer number with the occurrences of detection of the zero-cross of a focus error signal; and stopping the supply of the focus drive signal when the result of the comparison exhibits coincidence. 10. An optical disk reproducing apparatus substantially as herein described with reference to the accompanying drawings. 11. An optical disk reproducing method substantially as herein described with reference to the accompanying drawings. |
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2101-del-1995-correspondence-others.pdf
2101-del-1995-correspondence-po.pdf
2101-del-1995-description (complete).pdf
2101-del-1995-petition-138.pdf
Patent Number | 194317 | ||||||||
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Indian Patent Application Number | 2101/DEL/1995 | ||||||||
PG Journal Number | 46/2012 | ||||||||
Publication Date | 16-Nov-2012 | ||||||||
Grant Date | 03-Feb-2006 | ||||||||
Date of Filing | 16-Nov-1995 | ||||||||
Name of Patentee | SONY CORPORATION | ||||||||
Applicant Address | 7-35, KITASHINAGWA, 6-CHOME, SHINAGAWA-KU, TOKYO,JAPAN. | ||||||||
Inventors:
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PCT International Classification Number | G11B 7/09 | ||||||||
PCT International Application Number | N/A | ||||||||
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PCT Conventions:
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