Patent
Optical information processing apparatus and optical pickup therefor
| العنوان: | Optical information processing apparatus and optical pickup therefor |
|---|---|
| Patent Number: | 5,195,070 |
| تاريخ النشر: | March 16, 1993 |
| Appl. No: | 07/551,794 |
| Application Filed: | July 12, 1990 |
| مستخلص: | Using an optical pickup, recording/reproducing of information is performed by irradiating light beams to an optical recording medium to form light spots. The optical pickup includes means for generating plural light beams, an optical waveguide for guiding the plural light beams in a row into a flat space, and a light deflecting element for deflecting the light beams, which run in the optical waveguide, within a plane formed by a vector perpendicular to a plane of the optical waveguide and a directional vector of the light beams. The light deflecting element deflects the plural light spots, which are to be arranged in a row, in a direction perpendicular to the light spot row to perform micro seek. |
| Inventors: | Shiba, Masataka (Yokohama, JPX); Kawamoto, Kazumi (Yokohama, JPX); Hira, Yasuo (Yokohama, JPX); Inagaki, Akira (Yokohama, JPX); Sato, Hidemi (Yokohama, JPX); Ito, Kenchi (Yokohama, JPX); Fukushima, Atsuko (Yokohama, JPX); Funatsu, Ryuichi (Yokohama, JPX) |
| Assignees: | Hitachi, Ltd. (Tokyo, JPX) |
| Claim: | What is claimed is |
| Claim: | 1. An optical information processing apparatus for performing information process on an optical recording medium having tracks on which information is to be recorded, said apparatus comprising |
| Claim: | (a) an optical pickup for irradiating plural light beams to the recording medium and for detecting reflected light of the light beams; |
| Claim: | (b) a recording medium drive means for moving the recording medium relative to said optical pickup; and |
| Claim: | (c) a signal processing means for controlling the light beams of said optical pickup and for performing information process on the recording medium; |
| Claim: | (d) said optical pickup including at least one light source, an optical waveguide for guiding the light beams from said light source, a light deflecting element disposed in said optical waveguide for controllaby deflecting the light beams running in said optical waveguide, within a plane formed by a vector in that running direction and a vector perpendicular to a plane of said optical waveguide, based on a control signal from said signal processing means, an optical system for focusing the light beams, which are outputted from said light deflecting element, on the recording medium to form light spots, and sensor elements for detecting the reflected light from the recording medium. |
| Claim: | 2. An optical information processing apparatus according to claim 1, wherein said optical pickup includes means for generating the plural light beams. |
| Claim: | 3. An optical information processing apparatus according to claim 2, wherein said light beam generating means is composed of plural light emitting elements as said light source. |
| Claim: | 4. An optical information processing apparatus according to claim 2, wherein said light beam generating means includes means for dividing one light beam, which is emitted from said light source, into plural light beams. |
| Claim: | 5. An optical information processing apparatus according to claim 4, wherein said light source is a semiconductor laser as a light emitting element. |
| Claim: | 6. An optical information processing apparatus according to claim 4, wherein said light deflecting element includes means for forming a linear grating coupler from said optical waveguide by propagating a surface acoustic wave to said optical waveguide. |
| Claim: | 7. An optical information processing apparatus according to claim 6, wherein said linear grating coupler forming means is located so as to propagate the surface acoustic wave substantially in parallel to the running direction of the light beams. |
| Claim: | 8. An optical information processing apparatus according to claim 4, wherein said light deflecting element includes a linear grating coupler disposed on said optical waveguide, and means for generating an electric field in said optical waveguide to control an emitting angle of the light beams from the linear grating coupler. |
| Claim: | 9. An optical information processing apparatus according to claim 3, wherein said plural light emitting elements are arranged in such a manner that the light beams to be emitted to the recording medium form light spots in a row on the recording medium. |
| Claim: | 10. An optical information processing apparatus according to claim 9, wherein said optical pickup is located in such manner that the individual light spots are formed on adjacent tracks and that the row of the light spots is disposed at an angle to the track. |
| Claim: | 11. An optical information processing apparatus according to claim 9, wherein each of said plural light emitting elements is a semiconductor laser. |
| Claim: | 12. An optical information processing apparatus according to claim 10, wherein said light deflecting element includes means for forming a linear grating coupler from said optical waveguide by propagating a surface acoustic wave to said optical waveguide. |
| Claim: | 13. An optical information processing apparatus according to claim 12, wherein said linear grating coupler forming means is located so as to propagate the surface acoustic wave substantially in parallel to the running direction of the light beams. |
| Claim: | 14. An optical information processing apparatus according to claim 10, wherein said light deflecting element includes a linear grating coupler disposed on said optical waveguide, means for generating an electric field in said optical waveguide to control an emitting angle of the light beams from the linear grating coupler. |
| Claim: | 15. An optical information processing apparatus according to claim 9, wherein said light deflecting element is an acousto-optical element. |
| Claim: | 16. An optical information processing apparatus according to claim 9, wherein said optical pickup is capable of generating, in addition to the light beams for inputting and outputting information, two auxiliary light beams, the distance between light spots formed by the auxiliary light beams and the light spots formed by the light beams for inputting and outputting information being different a quarter from the distance between the light beams for inputting and outputting information. |
| Claim: | 17. An optical information processing apparatus according to claim 1, wherein the light deflecting element is a single light deflecting element, the optical system enabling formation of plural light spots extending in a row direction on the recording medium, the single light deflecting element being controlled so as to control the deflection of the light beams and enable movement of the plural light spots in a direction transverse to the row extension direction thereof. |
| Claim: | 18. An optical information processing apparatus according to claim 17, wherein at least three light beams form at least three light spots extending in the row direction on the recording medium, the at least three light spots being adjacent one another and being positionable on at least three adjacent tracks of the recording medium. |
| Claim: | 19. An optical information processing apparatus according to claim 17, wherein the optical pickup includes plural light generating elements as the light source for generating respective ones of the plural light beams. |
| Claim: | 20. An optical pickup for an optical information processing apparatus for performing information process on an optical recording medium having tracks on which information is to be recorded, said optical pickup comprising |
| Claim: | (a) at least one light source; |
| Claim: | (b) an optical waveguide for guiding plural light beams from said light source; |
| Claim: | (c) a transparent substrate for supporting said optical waveguide; |
| Claim: | (d) a light deflecting element for controllably deflecting the light beams, which run in said optical waveguide, so as to strike on said transparent substrate, based on a control signal from the information processing apparatus; |
| Claim: | (e) an optical system for focusing the deflected light beams as light spots on the recording medium; and |
| Claim: | (f) sensor elements for detecting reflected light of the light beams from the recording medium. |
| Claim: | 21. An optical pickup according to claim 20, wherein said optical waveguide is in the form of a layer on said tranparent substrate |
| Claim: | said light deflecting element including an exciter circuit for generating an exciting voltage having a frequency commensurate with the control signal, and an electrode disposed in said layer for generating a surface acoustic wave upon application of the exciting voltage and for propagating the surface acoustic wave in the running direction of the light beams, whereby an emitting angle of the light beams to transparent substrate is controlled according to the frequency of the exciting voltage applied to said electrode. |
| Claim: | 22. An optical pickup according to claim 20, wherein said optical waveguide is in the form of a layer on said transparent substrate |
| Claim: | said light deflecting element including a linear grating coupler disposed on said optical waveguide, an electrode for generating an electric field in said optical waveguide, and a voltage application circuit for applying an voltage to said electrode, whereby an emitting angle of the light beams to said transparent substrate is controlled according to the voltage applied to said electrode. |
| Claim: | 23. An optical pickup according to claim 21, wherein said light source includes plural light emitting elements which are able to be driven independently, whereby the plural light beams from said light emitting elements are introduced into said optical waveguide. |
| Claim: | 24. An optical pickup according to claim 22, wherein said light source includes plural light emitting elements which are able to be driven independently, whereby the plural light beams from said light emitting elements are introduced into said optical waveguide. |
| Claim: | 25. An optical information processing apparatus according to claim 20, wherein the light deflecting element is a single light deflecting element, the optical system enabling formation of plural light spots extending in a row direction on the recording medium, the single light deflecting element being controlled so as to control the deflection of the light beams and enable movement of the plural light spots in a direction transverse to the row extension direction thereof. |
| Claim: | 26. An optical information processing apparatus according to claim 20, wherein at least three light beams form at least three light spots extending in the row direction on the recording medium, the at least three being adjacent one another and light spots being positionable on at least three adjacent tracks of the recording medium. |
| Claim: | 27. An optical information processing apparatus according to claim 20, wherein the optical pickup includes plural light generating elements as the light source for generating respective ones of the plural light beams. |
| Claim: | 28. A method of tracking in an optical information processing apparatus, comprising |
| Claim: | (a) generating at least one first light beam for inputting and outputting information, and one or more second light beams for tracking; |
| Claim: | (b) introducing the first and second light beams into a light waveguide; |
| Claim: | (c) deflecting by a light deflecting element the first and second light beams, which run in said optical waveguide, within a plane formed by a running direction of the first and second light beams and a normal to a plane of said optical waveguide; |
| Claim: | (d) irradiating the deflected first and second light beams to the recording medium via an optical system to form light spots on the recording medium; |
| Claim: | (e) branching, from the optical system, the light beams struck on the optical system as reflected from the light spot; |
| Claim: | (f) detecting the branched light beam by sensor elements; |
| Claim: | (g) obtaining a tracking error signal from a detection signal concerning the second light beams; and |
| Claim: | (h) varying a deflection angle of the light deflecting element according to the tracking error signal in such a manner that the tracking error signal is zero. |
| Claim: | 29. A tracking method according to claim 28, wherein said deflecting is performed by propagating a surface acoustic wave to the optical waveguide in parallel to the running direction of the light beams, and the deflection angle is determined by varying the frequency of the surface acoustic wave according to the tracking error signal. |
| Claim: | 30. A tracking method according to claim 28, wherein said deflecting is performed by irradiating the light beams to the transparent substrate through a linear grating coupler disposed on the optical waveguide, and the deflection angle is determined by generating an electric field in the running direction of the light beams in the optical waveguide and by varying the intensity of the field according to the tracking error signal. |
| Claim: | 31. A tracking method according to claim 28, wherein the light deflecting element is a single light deflecting element, the optical system enabling the formation of plural light spots extending in a row direction on the recording medium, and varying a deflection angle of the light deflecting element controls the deflection of the light beams and enable movement of the light spots in a direction transverse to the row extension direction thereof. |
| Claim: | 32. A tracking method according to claim 28, wherein the at least one of the first and second light beams include at least three light beams forming at least three light spots extending in the row direction on the recording medium and being adjacent one another, the at least three adjacent light spots being positionable on at least three adjacent tracks of the recording medium. |
| Claim: | 33. A tracking method according to claim 28, wherein the step of generating includes utilizing plural light generating elements for generating respective ones of the first and second light beams. |
| Claim: | 34. A method of forming light spots in an optical information processing apparatus for performing information process on an optical recording medium having tracks on which information is to be recorded, said method comprising |
| Claim: | (a) emitting plural light beams from a light source in response to recordation or reproduction of information; |
| Claim: | (b) introducing the light beams from the light source into a flat optical waveguide; |
| Claim: | (c) deflecting by a deflecting element the light beams, which run in the optical waveguide, within a plane formed by a vector of the running direction of the light beams and a plane vector of the optical waveguide; and |
| Claim: | (d) irradiating the deflected light beams to the recording medium via an optical system. |
| Claim: | 35. A light spot forming method according to claim 34, wherein said deflecting is performed by propagating a surface acoustic wave to the optical waveguide in parallel to the running direction of the light beams, and the deflection angle is determined by varying the frequency of the surface acoustic wave according to the tracking error signal. |
| Claim: | 36. A light spot forming method according to claim 34, wherein said deflecting is performed by irradiating the light beams to the transparent substrate through a linear grating coupler disposed in the optical waveguide, and the deflection angle is determined by generating an electric field in the running direction of the light beams in the optical waveguide and by varying the intensity of the field according to the tracking error signal. |
| Claim: | 37. A method according to claim 34, wherein the light deflecting element is a single light deflecting element, the deflected light beams enabling the formation of plural light spots extending in a row direction on the recording medium, and varying a deflection angle of the light deflecting element to control the deflection of the light beams and enable movement of the light spots in a direction transverse to the row extension direction thereof. |
| Claim: | 38. A method according to claim 34, wherein the plural light beams include at least three light beams forming at least three light spots extending in the row direction on the recording medium and being adjacent one another, the at least three adjacent light spots being positionable on at least three adjacent tracks of the recording medium. |
| Claim: | 39. A method according to claim 34, wherein the step of emitting includes utilizing plural light generating elements for emitting respective ones of the plural light beams. |
| Claim: | 40. An optical information processing apparatus for performing information process on an optical recording medium having tracks on which information is to be recorded, said apparatus comprising |
| Claim: | (a) means for generating plural light beams; |
| Claim: | (b) means for guiding the plural light beams in a row into a flat space; |
| Claim: | (c) means including a light deflecting element for deflecting all of the light beams, which run in the flat space, within a plane formed by a directional vector of the light beams and a vector of a plane in which the light beams are arranged in a row; |
| Claim: | (d) an optical system for irradiating reflected light beams on the recording medium to form light spots thereon; |
| Claim: | (e) means for detecting the deflected light beams from the recording medium; |
| Claim: | (f) means for obtaining a tracking error from a detection signal from said detecting means; |
| Claim: | (g) means for controlling a deflection angle of the light beams in such a manner that the tracking error is zero; and |
| Claim: | (h) a reproducing means for reading, from the detection signal, information recorded on the tracks of the recording medium. |
| Claim: | 41. An optical information processing apparatus according to claim 40, further comprising |
| Claim: | (a) information recording means for recording information on the recording medium; |
| Claim: | (b) said plural light beam generating means being composed of plural light emitting elements which are able to be driven independently; and |
| Claim: | (c) said information recording means having a function of coding a signal including data to be recorded and a function of driving, of the light emitting elements, those to be used for recordation of information. |
| Claim: | 42. An optical information processing apparatus according to claim 40, wherein the light deflecting element is a single light deflecting element, the optical system enabling formation of plural light spots extending in a row direction on the recording medium, the single light deflecting element being controlled so as to control the deflection of the light beams and enable movement of the plural light spots in a direction transverse to the row extension direction thereof. |
| Claim: | 43. An optical information processing apparatus according to claim 40, wherein at least three light beams forming at least three light spots extending in the row direction on the recording medium and being adjacent one another, the at least three adjacent light spots being positionable on at least three adjacent tracks of the recording medium. |
| Claim: | 44. An optical information processing apparatus according to claim 40, wherein the optical pickup includes plural light generating elements as the light source for generating respective ones of the plural light beams. |
| Claim: | 45. A method of optically processing information on an optical recording medium having tracks, comprising |
| Claim: | (a) forming plural laser light spots for inputting and outputting information, on the recording medium via an optical system having an optical waveguide with a light deflecting element; |
| Claim: | (b) arranging the plural laser light spots in a row; |
| Claim: | (c) irradiating the laser light spots respectively to the adjacent tracks in such a manner that the row of the laser light spots is disposed at an angle to the tracks on the recording medium; |
| Claim: | (d) detecting reflected light beams from the laser light spots on the recording medium respectively by plural sensors; and |
| Claim: | (e) scanning the row of the laser light spots, at the same time, in a direction substantially perpendicular to the tracks by controlling the light deflecting elements of the optical system to perform a tracking control of the row of the laser light spots collectively. |
| Claim: | 46. A method according to claim 45, wherein the light deflecting element is a single light deflecting element, and varying a deflection angle of the light deflecting element to enable movement of the light spots in the direction perpendicular to the tracks. |
| Claim: | 47. A method according to claim 45, wherein at least three light beams forming at least three light spots extending in the row direction on the recording medium and being adjacent one another are formed, the at least three adjacent light spots being positionable on at least three adjacent tracks of the recording medium. |
| Claim: | 48. A method according to claim 45, further including utilizing plural light generating elements for generating respective ones of the plural light spots. |
| Current U.S. Class: | 369/4412; 369/112 |
| Current International Class: | G11B 1114 |
| Patent References Cited: | 3655261 April 1972 Chang 4737946 April 1988 Yamashita et al. 4887255 December 1989 Handa et al. 4910723 March 1990 Yamamoto 4991160 February 1991 Premji |
| Other References: | Efficient Accousto Optical Coupling of Guided to Substrate Modes in a Combined Acoustical/Optical Channel Guide, V. Hinkov, U. Nolte and W. Sohler, pp. 138-141. |
| Primary Examiner: | Chin, Tommy P. |
| Assistant Examiner: | Chevalier, Robert |
| Attorney, Agent or Firm: | Antonelli, Terry, Stout & Kraus |
| رقم الانضمام: | edspgr.05195070 |
| قاعدة البيانات: | USPTO Patent Grants |
| الوصف غير متاح. |