JPS5522268A - Record disk detecting device - Google Patents

Record disk detecting device

Info

Publication number
JPS5522268A
JPS5522268A JP9485078A JP9485078A JPS5522268A JP S5522268 A JPS5522268 A JP S5522268A JP 9485078 A JP9485078 A JP 9485078A JP 9485078 A JP9485078 A JP 9485078A JP S5522268 A JPS5522268 A JP S5522268A
Authority
JP
Japan
Prior art keywords
record disk
ambient light
pulses
detecting device
turntable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP9485078A
Other languages
Japanese (ja)
Inventor
Akira Oinuma
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP9485078A priority Critical patent/JPS5522268A/en
Publication of JPS5522268A publication Critical patent/JPS5522268A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
    • G11B19/12—Control of operating function, e.g. switching from recording to reproducing by sensing distinguishing features of or on records, e.g. diameter end mark
    • G11B19/124—Control of operating function, e.g. switching from recording to reproducing by sensing distinguishing features of or on records, e.g. diameter end mark involving the detection of diameter of disks

Landscapes

  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To eliminate the effect of the ambient light and thus to obtain an economical detecting device which is free from malfunction by using in time division one unit of the photoelectric conversion element to detect optically the record disk on the turntable and thus detecting the level of the ambient light. CONSTITUTION:Three units of through-holes 2a, 2b and 2c are provided on turntable 1 to identify the size of the record disk, and the light given from light emitting diodes 4a, 4b and 4c provided on substrate 3 are transmitted through the three through-holes to be put into photoelectric conversion element 5. Then the pulse of frequency of about 1KHz from oscillator 7 of logic arithmetic circuit 6 is converted into four-phase pulses A, B, C and K. Thus diodes 4a, 4b and 4c are emitted in time division and sequentially via pulses A, B and C each, and at the same time the output voltage of element 5 is memorized and held in analog memory element 15 in the generation period of pulse K. This held voltage value M is compared with output voltage L of element 5 at comparator 16, and the effect of the ambient light is subtracted. This output N then undergoes a logic operation with pulses A, B and C to obtain signals G, H and I to identify the size of the record disk.
JP9485078A 1978-08-02 1978-08-02 Record disk detecting device Pending JPS5522268A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9485078A JPS5522268A (en) 1978-08-02 1978-08-02 Record disk detecting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9485078A JPS5522268A (en) 1978-08-02 1978-08-02 Record disk detecting device

Publications (1)

Publication Number Publication Date
JPS5522268A true JPS5522268A (en) 1980-02-16

Family

ID=14121497

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9485078A Pending JPS5522268A (en) 1978-08-02 1978-08-02 Record disk detecting device

Country Status (1)

Country Link
JP (1) JPS5522268A (en)

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