Title of Invention

" AN OPTICAL DISC REPRODUCING APPARATUS AND METHOD"

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)
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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.

Documents:

2101-del-1995-abstract.pdf

2101-del-1995-claims.pdf

2101-del-1995-correspondence-others.pdf

2101-del-1995-correspondence-po.pdf

2101-del-1995-description (complete).pdf

2101-del-1995-drawings.pdf

2101-del-1995-form-1.pdf

2101-del-1995-form-13.pdf

2101-del-1995-form-2.pdf

2101-del-1995-form-3.pdf

2101-del-1995-form-4.pdf

2101-del-1995-gpa.pdf

2101-del-1995-petition-138.pdf

abstract.jpg


Patent Number 194317
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:
# Inventor's Name Inventor's Address
1 MASANOBU NISHIKATA C/O. SONY CORPORATION, 7-35, KITASHINAGWA, 6-CHOME, SHINAGAWA-KU, TOKYO,JAPAN.
PCT International Classification Number G11B 7/09
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA