Patent EP0162702A1 successfully refreshed from Google Patents.
EP0162702A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Tracking control arrangements for use in optical disc players
Assignee: Sony Corp
•
Filing: 1985-05-21
•
Granted: —
•
Expires: 2005-05-21
Abstract
Abstract A tracking control arrangement for use in an optical disc player comprises a photodetector (13) for receiving a light beam reflected at an optical disc on which an information signal is recorded in a record track, signal generating circuit (14) for generating a reproduced information signal and a tracking error signal from the output of the photodetector (13), a modifier (23, 24) for modifying the tracking error signal in response to variations in the total quantity of light of the light beam received by the photodetector (13), driving means (10,25,26) for driving an optical device to maintain the light beam in a proper tracking relation to the record track in response to the modified tracking error signal, a detector (31, 32,33) for detecting a variation in the reproduced information signal resulting from the condition in which the light beam reflected at a blank area in the record track is received by the photodetector (13), and a gain controller (30) for varying the gain of transmission of the modified tracking error signal from the modifier to the driving means in response to a predetermined detection output of the detector (31, 32, 33).
Inventors
- 👤 Mitsutoshi C/O Sony Corporation Shinkai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 07:13
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0938; G11B7/0901; G11B7/0941
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
274 words
- - A tracking control arrangement for use in an optical disc player having an optical device for causing a light beam to impinge on an optical disc on which an information signal is recorded in a record track containing a recorded area and a blank area, the tracking control arrangement comprising; photodetecting means (13) for receiving a light beam reflected at the optical disc to produce an output in response to the light beam received thereby, signal generating means (14) for generating a first signal corresponding to the information signal recorded on the optical disc and a second signal representing tracking error of the light beam impinging on the optical disc from the output of said photodetecting means (13), signal modifying means (23, 24) for modifying said second signal in response to variations in the total quantity of light of the light beam received by said photodetecting means (13) to produce a modified signal, driving means (10, 25, 26) for driving the optical device to maintain the light beam impinging on the optical disc in a predetermined tracking relation to the record track on the optical disc in response to said modified signal, detecting means (31, 32, 33) for detecting a variation in said first signal resulting from the condition in which the light beam reflected at the blank area in the record track is received by said photodetecting means (13), and gain control means (30) for transmitting said modified signal to said driving means (10, 25, 26) and verying the gain for transmission of said modified signal in response to a predetermined detection output obtained from said detecting means (31, 32, 33).
Claim 2
Dependent Claim
274 words
- - A tracking control arrangement for use in an optical disc player having an optical device for causing a light beam to impinge on an optical disc on which an information signal is recorded in a record track containing a recorded area and a blank area, the tracking control arrangement comprising; photodetecting means (13) for receiving a light beam reflected at the optical disc to produce an output in response to the light beam received thereby, signal generating means (14) for generating a first signal corresponding to the information signal recorded on the optical disc and a second signal representing tracking error of the light beam impinging on the optical disc from the output of said photodetecting means (13), signal modifying means (23, 24) for modifying said second signal in response to variations in the total quantity of light of the light beam received by said photodetecting means (13) to produce a modified signal, driving means (10, 25, 26) for driving the optical device to maintain the light beam impinging on the optical disc in a predetermined tracking relation to the record track on the optical disc in response to said modified signal, detecting means (31, 32, 33) for detecting a variation in said first signal resulting from the condition in which the light beam reflected at the blank area in the record track is received by said photodetecting means (13), and gain control means (30) for transmitting said modified signal to said driving means (10, 25, 26) and verying the gain for transmission of said modified signal in response to a predetermined detection output obtained from said detecting means (31, 32, 33).
Claim 3
Dependent Claim
75 words
A tracking control arrangement according to claim 1, wherein said photodetecting means (13) comprises a first light receiving portion (16) for producing a first component of said output from which said first signal is generated and a second light receiving portion (15) including a pair of light detecting elements (15A, 15B) for producing respectively first and second light detection output signals forming a second component of said output from which said second signal is generated.
Claim 4
Dependent Claim
58 words
A tracking control arrangement according to claim 2, wherein said signal generating means (14) comprises a first signal processing portion (19, 20, 21) for processing said first component to produce said first signal and a second signal processing portion (18) for making the difference between said first and second light detection output signals to produce said second signal.
Claim 5
Dependent Claim
98 words
A tracking control arrangement according to claim 1, wherein said signal modifying means (23, 24) comprises control signal producing means (23) for producing a control signal having the amplitude varying in response to variations in the amplitude of said first signal resulting from the variations in the total quantity of light of the light beam received by said photodetecting means (13) and a dividing circuit (24) operative to perform the operation equivalent to a division for dividing a value corresponding to the amplitude of said second signal by a value corresponding to the amplitude of said control signal.
Claim 6
Dependent Claim
25 words
A tracking control arrangement according to claim 4, wherein said control signal producing means comprises a low pass filter (23) supplied with said first signal.
Claim 7
Dependent Claim
74 words
A tracking control arrangement according to claim 1, wherein said detecting,means (31, 32, 33) comprises a capacitor (31) for eliminating a DC component of said first signal to produce thereby a level shifted signal and an envelope detecting circuit (32) for detecting the envelope of said level shifted signal and producing an envelope detection output having a level varying in response to the detected envelope to be supplied to said gain control means (30).
Claim 8
Dependent Claim
62 words
A tracking control arrangement according to claim 6, wherein said gain control means comprises a gain control circuit (30) having an input terminal supplied with said modified signal, a control terminal supplied with said envelope detection output and an output terminal at which said modified signal is obtained with the level controlled in response to the level of said envelope detection output.
Claim 9
Dependent Claim
61 words
A tracking control arrangement according to claim 6, wherein said detecting means (31, 32, 33) further comprises a OR gate circuit (33) connected between said enveloge detecting circuit (32) and said gain control means (30) to be supplied with said envelope detection output and an additional signal obtained in connection with a track jump operation performed in the optical disc player.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.