Hologram apparatus

• US 4,021,606 A
• Filed: 03/27/1975
• Issued: 05/03/1977
• Est. Priority Date: 03/27/1974
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tsunoda, Yoshito, Kataoka, Keiji, Tatsuno, Kimio, Takeda, Yasutsugu, Imagawa, Fumio
• Primary Examiner(s): Stern, Ronald J.
• Application Number:
  US05/562,394
• Time in Patent Office: 768 Days
• Field of Search: 350/3.5, 178/6.7 R, 178/6.7 A, 178/6.6 DD, 179/100.3 G, 179/100.3 V, 346/108
• US Class Current: 386/318
• CPC Class Codes: G03H 1/0236 Form or shape of the hologram when not registered to the substrate, e.g. trimming the hologram to alphanumerical shape substrates bearing a hologram G03H1/0272
• CPC Class Codes: G03H 1/16 using Fourier transform G03H1/10, G03H1/12, G03H1/14 take precedence; analogue computers G06G, e.g. G06G7/19
• CPC Class Codes: G03H 1/30 discrete holograms only
• CPC Class Codes: G03H 2001/0204 Object characteristics corresponding details, see subgroups of G03H2210/00
• CPC Class Codes: G03H 2210/20 2D object
• CPC Class Codes: G03H 2230/10 Microhologram not registered to the substrate
• CPC Class Codes: G03H 2270/22 Disc shaped
• CPC Class Codes: G11B 7/0065 Recording, reproducing or erasing by using optical interference patterns, e.g. holograms
• CPC Class Codes: H04N 5/7605 on discs or drums H04N5/781, H04N5/805, H04N5/83, H04N5/85 take precedence
• CPC Class Codes: H04N 5/90 on discs or drums

Abstract

A hologram apparatus comprises a rotary plane with a plurality of holograms concentrically or spirally arranged thereon, a light emitting source, and at least one photodetector for reading out reconstructed images of the holograms. During rotation of the rotary plane, the optical path of a light beam from the light emitting source is controlled, whereby the reconstructed images from the respective holograms are focused on the photodetector in succession. Some or all of the holograms are substantially oblong, and the long side and the short side of each oblong extend radially about the axis of the rotary plane and substantially orthogonally to the radial direction respectively.

Claims

1. A hologram apparatus comprising:

a light source;

a hologram recording medium upon which are recorded a series of oblong-shaped holograms, each of which is the hologram of an optical representation of a respective one of a plurality of discontinuous encoded signals, each encoded signal corresponding to a portion of a continuous information signal periodically converted into a series of said discontinuous encoded signals, each discontinuous encoded signal being formed of a plurality of bits corresponding to the value of a respectively converted portion of said continuous information signal;

optical detecting means;

means for causing light from said light source to be sequentially directed upon said series of oblong-shaped holograms and to thereby form a series of reconstructed images of the optical representations of the discontinuous encoded signals, sequentially formed at said optical detecting means, said optical detecting means thereby producing a series of electrical signals representative of said discontinuous encoded signals; and

means, coupled to said optical detecting means, for decoding said series of electrical signals into said continuous information signal, wherein

said continuous information signal is an audio signal and wherein said hologram recording medium further includes a plurality of holograms of video information, with each of which holograms of video information plural ones of said series of oblong-shaped holograms are associated and are disposed adjacent to their associate holograms of video information,

said light directing means includes means for causing light from said light source to be directed upon a respective hologram of video information during the sequential direction of light upon its associated plural ones of said series of oblong-shaped holograms,

said detecting means includes means for detecting a reconstructed image of video information from the holograms of video information during production of said series of electrical signals representative of said discontinuous encoded signals, and

said decoding means includes means for reproducing said video information during the decoding of said series of electrical signals into said audio signal, and wherein

the long side of each oblong-shaped hologram is arranged orthogonal to the direction of sequential direction of light from said light directing means upon said series of oblong-shaped holograms.

2. A hologram apparatus according to claim 1, wherein said hologram recording medium comprises a rotatable cylinder, with said series of oblong-shaped holograms being arranged at the surface of said cylinder in a row traversing the rotational direction of said cylinder, with the long side of each oblong-shaped hologram being arranged orthogonal to said rotational direction.

3. A hologram apparatus according to claim 2, wherein the surface of said cylinder contains a plurality of series of said oblong-shaped holograms arranged in parallel rows.

4. A hologram apparatus according to claim 1, wherein each hologram of video information is circular, adjacent to which associated plural ones of said series of oblong-shaped holograms are disposed.

5. A hologram apparatus according to claim 4, wherein said recording medium is disc-shaped, upon which said circular holograms and said oblong-shaped holograms are arranged along first and second respective spiral tracks disposed adjacent to one another, with the long side of each of said oblong-shaped holograms being disposed along a radial line of said disc and said spiral tracks being arranged so that, during traverse of a radial line of said disc, said first and second spiral tracks are alternately encountered.

6. A hologram recording comprising a hologram recording medium upon which are recorded a series of oblong-shaped holograms, each of which is the hologram of an optical representation of a respective one of a plurality of discontinuous encoded signals, each encoded signal corresponding to a portion of a continuous information signal periodically converted into a series of said discontinuous encoded signals, each discontinuous encoded signal being formed of a plurality of bits corresponding to the value of a respectively converted portion of said continuous information signal, wherein

said continuous information signal is an audio signal and wherein said hologram recording medium further includes a plurality of holograms of video information, with each of which holograms of video information plural ones of said series of oblong-shaped holograms are associated and are disposed adjacent to their associated hologram of video information, and wherein

the long side of each side oblong-shaped hologram is arranged orthogonal to the direction along which said series of oblong-shaped holograms are recorded on said hologram recording medium.

7. A hologram recording according to claim 6, wherein said hologram recording medium comprises a rotatable cylinder, with said series of oblong-shaped holograms being arranged at the surface of said cylinder in a row traversing the rotational direction of said cylinder, with the long side of each oblong-shaped hologram being arranged orthogonal to said rotational direction.

8. A hologram recording according to claim 7, wherein the surface of said cylinder contains a plurality of series of said oblong-shaped holograms arranged in parallel rows.

9. A hologram recording according to claim 6, wherein each hologram of video information is circular, adjacent to which associated plural ones of said series of oblong-shaped holograms are disposed.

10. A hologram recording according to claim 9, wherein said recording medium is disc-shaped, upon which said circular holograms and said oblong-shaped holograms are arranged along first and second respective spiral tracks disposed adjacent to one another, with the long side of each of said oblong-shaped holograms being disposed along a radial line of said disc and said spiral tracks being arranged so that, during traverse of a radial line of said disc, said first and second spiral tracks are alternately encountered.