Flying optical recording/playback head and method for controlling the flying height
AssigneeTosoh Corporation
InventorKoji Katayama
Life of this patent
Estimating the term…
Abstract
A flying optical recording/playback head for near-field optical recording/playback, which is capable of keeping the flying height of an optical lens to be constant and obtaining a stable playback signal, is provided. In the flying optical recording/playback head, a device for controlling the relative position between a slider and the optical lens based on a thermal expansion or a piezoelectric effect of an optical lens supporting member for holding the optical lens on the slider, or a thermal expansion of a portion of the optical lens.
Claims22
A near-field optical recording/playback system having a flying optical recording/playback head, said flying optical recording/playback head comprising:
- a slider for producing buoyancy by a movement of an optical recording medium,
- an optical element for irradiating light for information-recording and/or playback to the optical recording medium, and
- a controlling device for controlling the relative position between the slider and a nearest surface of the optical element, which is nearest to the optical recording medium,
- wherein the relative position is controlled by said controlling device so that the returning light intensity as the sum total of a returning light quantity from the lowest portion of the optical element and a reflection light quantity from the optical recording medium is constant, so that the flying height of the flying optical recording/play back head is controlled to be constant.
A near-field optical recording/playback system having a flying optical recording/playback head, said flying optical recording/playback head comprising:
- a slider for producing buoyancy by a movement of an optical recording medium,
- an optical element for irradiating light for information-recording and/or playback to the optical recording medium, said optical element having a photo-coupling portion having a flat plane substantially parallel to the surface of the optical recording medium at a side opposing to the optical recording medium, and
- a controlling device for controlling the relative position between the slider and the photo-coupling portion,
- wherein the relative position is controlled by said controlling device so that the returning light intensity as the sum total of a returning light quantity from the photo-coupling portion and a reflection light quantity from the optical recording medium is constant, so that the flying height of the flying optical recording/play back head is controlled to be constant.
A near-field optical recording/playback system having a flying optical recording/playback head, said flying optical recording/playback head comprising:
- a slider for producing buoyancy by a movement of an optical recording medium,
- an optical element attached to the slider to irradiate light for information-recording and/or playback to the optical recording medium,
- said optical element attached to the slider having a flat plane at a light emitting side, a cylindrical projection projecting in a cylindrical form formed in a portion of the flat plane, and a thin layer having an electric resistance formed on the side surface of the cylindrical projection, and
- a controlling device for controlling the distance between the photo-coupling portion comprising the end plane of the cylindrical projection and the optical recording medium by utilizing a change of the shape of the cylindrical projection due to a thermal expansion, which is caused by supplying power to the thin layer having an electric resistance,
- wherein the relative position is controlled by said controlling device so that the returning light intensity as the sum total of a returning light quantity from the photo-coupling portion and a reflection light quantity from the optical recording medium is constant, so that the flying height of the flying optical recording/playback head is controlled to be constant.
A method for controlling the flying height of a flying optical recording/playback head used in a near-field optical recording/playback system, characterized by using:
- a flying optical recording/playback head comprising a slider for producing buoyancy by a movement of an optical recording medium,
- an optical element for irradiating light for information-recording and/or playback to the optical recording medium, and
- a controlling device for controlling the relative position between the slider and a nearest surface of the optical element, which is nearest to the optical recording medium,
- wherein the relative position is controlled by said controlling device so that the returning light intensity as the sum total of a returning light quantity from the lowest portion of the optical element and a reflection light quantity from the optical recording medium is constant.
A method for controlling the flying height of a flying optical recording/playback head used in a near-field optical recording/playback system, characterized by using:
- a flying optical recording/playback head comprising a slider for producing buoyancy by a movement of an optical recording medium,
- an optical element for irradiating light for information-recording and/or playback to the optical recording medium, said optical element having a photo-coupling portion having a flat plane substantially parallel to the surface of the optical recording medium at a side opposing to the optical recording medium, and
- a controlling device for controlling the relative position between the slider and the photo-coupling portion,
- wherein the relative position is controlled by said controlling device so that the returning light intensity as the sum total of a returning light quantity from the photo-coupling portion and a reflection light quantity from the optical recording medium is constant.
A method for controlling the flying height of a flying optical recording/playback head used in a near-field optical recording/playback system, characterized by using:
- a flying optical recording/playback head comprising a slider for producing buoyancy by a movement of an optical recording medium;
- an optical element attached to the slider to irradiate light for information-recording and/or playback to the optical recording medium,
- said optical element attached to the slider having a flat plane at a light emitting side, a cylindrical projection projecting in a cylindrical form formed in a portion of the flat plane, and a thin layer having an electric resistance formed on the side surface of the cylindrical projection;
- and
- a controlling device for controlling the distance between the photo-coupling portion comprising the end plane of the cylindrical projection and the optical recording medium by utilizing a change of the shape of the cylindrical projection due to a thermal expansion, which is caused by supplying power to the thin layer having an electric resistance,
- wherein the relative position is controlled by said controlling device so that the returning light intensity as the sum total of a returning light quantity from the photo-coupling portion and a reflection light quantity from the optical recording medium is constant.
Dependencies are inferred from the claim text.