PHOTOGRAPHIC RECORD OF DIGITAL INFORMATION AND PLAYBACK SYSTEM INCLUDING OPTICAL SCANNER

• US 3,624,284 A
• Filed: 09/12/1969
• Issued: 11/30/1971
• Est. Priority Date: 09/01/1966
• Status: Expired due to Term

• Current Assignee: Optical Recording Corp.
• Original Assignee: James T. Russell
• Inventors: Russell, James T.
• Application Number:
  US04/857,474
• Time in Patent Office: 809 Days
• US Class Current: 369/44.13
• CPC Class Codes: G11B 2220/218 Write-once discs
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: G11B 7/00 Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor G11B11/00, G11B13/00 take precedence
• CPC Class Codes: G11B 7/0033 with cards or other card-like flat carriers, e.g. flat sheets of optical film
• CPC Class Codes: G11C 13/04 using optical elements ; using other beam accessed elements, e.g. electron or ion beam
• CPC Class Codes: H04N 3/08 having a moving reflector
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 5/926 by pulse code modulation H04N5/919 takes precedence

Abstract

An electrical signal-recording and playback system is described in which an analog input signal is converted to a digital signal that pulses a light source to form a single, series-recorded track of binary coded digital information including information spots arranged in groups separated by synchronizing spots recorded on a photographic film which is played back in a similar manner. The photographic film is a compact, permanent record of long, useful lifetime which may be photographically copied to provide a plurality of inexpensive copies. A spiral track photographic record is used in one embodiment which can be employed to provide a music system of high quality.

Claims

1. Playback apparatus for playing back a photographic record of digital information, comprising:

means for supporting in a fixed position a photographic record element having thereon a photographic image of a light signal correlated to a digital electrical input signal and being in the form of a plurality of spots in a single series-recorded track representing digital information recorded at a high density on said record element, said track including information spots arranged in groups separated by synchronizing spots in series with said information spots on the same track and of a different size than said information spots;

detector means including at least one light detector supported in a fixed position;

scanner means including a light-deflection means for scanning said record element along said track of spots to transmit a light signal to the detector so that said detector generates an electrical signal for each spot in the scanned portion of said track to produce an electrical output signal in the form of a digital coded signal correlated to the light signal recorded on said record element; and

output means connected to said detector means for transmitting said output signal from said detector means to a utilization device.

2. A photographic record of digital information comprising:

a record element having a photographic image of a plurality of digital information spots recorded thereon; and

said spots being recorded in series to provide a single track of spots positioned consecutively along said track with each spot located a different distance from the start of said track, said track including information spots arranged in groups separated by synchronizing spots in series with said information spots on the same track and of a different size than said information spots.

3. A record in accordance with claim 2 in which the track follows a sequential straight line path to form a rectangular raster pattern.

4. A record in accordance with claim 2 in which synchronizing spots of larger size than the word information spots are recorded between digital word groups of said information spots.

5. Optical scanner apparatus comprising:

a rotatable support;

a leaf spring fixed at one end to said support at a position spaced from the axis of rotation of said support;

a mirror attached to said leaf spring and positioned along said axis of rotation;

motor means for rotating said support;

magnetic deflection means for bending said spring to radially deflect said mirror in response to an electrical control signal to provide a spiral-shaped scan track for said mirror;

a weight attached to the free end of said spring on the opposite side of the axis of rotation from the fixed end of said spring to cause deflection of the spring by centrifugal force;

said spring moving said mirror away from the image plane being scanned as said mirror is deflected radially inward in order to maintain the optical path length substantially constant during scanning; and

control means connected to said motor means, for varying the speed of rotation of said support so that said speed increases as said mirror is deflected radially inward.

6. Playback apparatus for playing back a photographic record of digital information, comprising:

means for supporting in a fixed position a photographic record element having thereon a photographic image of a light signal correlated to a digital electrical input signal and being in the form of a plurality of spots in a single series-recorded track representing digital information recorded at a high density on said record element, said track including information spots arranged in groups separated by synchronizing spots in series with said information spots on the same track and distinguishable from said information spots;

detector means including at least one light detector supported in a fixed position;

scanner means including a light-deflection means for scanning said record element along said track of spots to transmit a light signal to the detector so that said detector generates an electrical signal for each spot in the scanned portion of said track to produce an electrical output signal in the form of a digital coded signal correlated to the light signal recorded on said record element; and

output means connected to said detector means for transmitting said output signal from said detector means to a utilization device.

7. Playback apparatus in accordance with claim 6 in which the light-deflection means includes a rotating mirror supported on a leaf spring fixed at One end to a rotatable support at a position spaced from the axis of rotation of said support, motor means for rotating said support about said axis, and magnetic deflection means for bending said spring to radially deflect said mirror in response to an electrical control signal to provide a spiral-shaped scan track for said mirror.

8. Playback apparatus in accordance with claim 7 in which the record element is a sheet of photographic film and said mirror is supported to move away from said photographic element as said mirror is deflected radially inward in order to maintain substantially the same optical path length during scanning.

9. Playback apparatus in accordance with claim 8 in which a weight is secured to the free end of the spring on the opposite side of the axis of rotation from the fixed end of said spring to cause deflection of the spring by centrifugal force, and said motor means includes means for varying the speed of rotation of the mirror support so that said speed increases as said mirror is deflected radially inward.

10. Playback apparatus in accordance with claim 6 in which the output means includes a converter means for converting the digital electrical output signal into an analog output signal.

11. Playback apparatus in accordance with claim 10 in which the light-deflection means includes a rotating mirror means and a means for deflecting said mirror means to enable it to scan the entire length of the track of spots, and which also includes a tracking means connected between the detector means and the scanner means for following said track.

12. Playback apparatus in accordance with claim 11 in which the tracking means oscillates said mirror means to cause the detected portion of the record to move back and forth across the track to produce an electrical control signal which is transmitted to the scanner means to maintain said detected portion on said track.

13. Playback apparatus in accordance with claim 11 in which the detector means includes a pair of light detectors positioned on the opposite sides of said track, and the tracking means is connected to the outputs of said detectors for producing an electrical control signal corresponding to the difference between the two signals generated by said pair of detectors and for applying said control signal to said scanner means to maintain the viewing fields of said detectors on said track.

14. Playback apparatus for playing back a photographic record of digital information, comprising:

means for supporting in a fixed position a photographic record element having thereon a photographic image of a light signal correlated to a digital electrical input signal and being in the form of a plurality of spots in a single series-recorded track representing digital information recorded at a high density on said record element, said track including information spots arranged in groups separated by synchronizing spots in series with said information spots on the same track and distinguishable from said information spots;

detector means including at least one light detector supported in a fixed position;

scanner means including a fixed light source and a light deflection means for scanning said record element along said track of spots to transmit a light signal to the detector so that said detector generates an electrical signal for each spot in the scanned portion of said track to produce an electrical output signal in the form of a digital coded signal correlated to the light signal recorded on said record element; and

output means connected to said detector means for transmitting said output signal from said detector means to a utilization device.

15. A photographic record of digital information comprising:

a record element having a photographic image of a plurality of digital information spots and synchronizing spots recorded thereon; and

said spots being recorded in a series track of spots in which the information spots are arranged in groups separated by said sYnchronizing spots in series with said information spots on the same track and distinguishable from said information spots.

16. A record in accordance with claim 15 in which the record element is a photographic film while the spots are less than about 0.01 millimeter in diameter and the spot density is greater than about 10 6 spots per square inch.

17. A record in accordance with claim 15 in which the track has a spiral shape.

18. A record in accordance with claim 15 in which the record element is a flat glass plate having a layer of photosensitive material thereon.