Information retrieval system and apparatus

An electro-optical data retrieval system for retrieving data from a storage medium and of the type wherein relative motion is imparted between the recording medium and a pickup means for causing said data to be scanned for retrieval thereof, the position of the data being capable of variation relative to the pickup means, comprising:

• means for receiving a data-bearing storage medium having a relatively high density of data tracks thereon,
• illuminance means for illuminating at least an area of interest of said storage medium,
• focusing means,
• a matrix array of photosensitive elements, disposed relative to said storage medium such that said focusing means may focus an image of said area of interest onto said array of photosensitive elements, the image of a data track being no smaller than a single photosensitive element, said array being dimensioned such that the area of interest does not extend beyond the array even in the event the position of data in the area of interest varies relative to the array,
• current-sensing preamplifier means and select circuit means associated with said photosensitive elements, said select circuit means being for selecting at least one of the photosensitive elements through said preamplifier means to provide an output signal responsive to said image impinging upon said photosensitive elements,
• tracking means for detecting variations in the position of the data and thereby selecting the photosensitive element which provides the output signal in response to such variation,
• velocity detection means including external clock means responsive to signals from at least one of said photosensitive elements for determining increases and decreases in the rotational velocity of said storage medium, and
• switching means responsive to said velocity detection means for selecting from said photosensitive elements at least one of said elements positioned so that the information to be retrieved is present at that element at the proper time as determined by said velocity detection means.

An electro-optical data retrieval system for retrieving data from a relatively high density data storage medium and of the type wherein relative motion is imparted between the recording medium and a pickup means for causing said data to be scanned for the retrieval thereof, comprising:

• illuminance means for illuminating an area of said storage medium,
• detector means including a matrix array of photosensitive elements disposed in rows and columns, a plurality of said photosensitive elements in at least one of said rows being continually biased,
• focusing means for focusing an image of an area of interest within said illuminated area of said storage medium onto said detector means, said array being dimensioned such that the area of interest does not extend beyond such array,
• amplifier means for amplifying signals produced by a plurality of elements of said photosensitive array,
• select circuit means for selecting at least one of said amplified signals to be provided as an output signal, said select circuit including register means,
• velocity detecting means including external clock means responsive to signals from at least one of said photosensitive elements for determining increases and decreases in the rotational velocity of said storage medium, and
• switching means responsive to said velocity detection means for selecting from said photosensitive elements at least one of said elements positioned so that the information to be retrieved is present at that element at the proper time as determined by said velocity detection means.

An electro-optical data retrieval system for retrieving data from a storage disc wherein relative rotational motion is imparted between the storage disc and a pickup means for causing the disc to be scanned for retrieval of the stored data therefrom comprising:

• means for receiving a storage disc having data stored thereon in data tracks,
• illuminace means on one side of the storage disc for flooding with radiation an area of the storage disc greater than a primary area of interest of at least one data track,
• detector means adapted for connection to processing circuitry including a matrix array of photodiodes located on the other side of the storage disc,
• focusing means between the storage medium receiving plane and the detector means for focusing an image of at least a primary area of interest of the storage medium caused by the illuminance means onto the detector means, the array size being greater than permissible eccentricities in data track position,
• monitor circuit means for monitoring a plurality of photodiodes in the matrix array which receive the image of the primary area of interest and selecting, in accordance with a predetermined criteria, one of the plurality to provide an output signal, the monitoring circuit means including means for causing the photodiodes included in the monitored plurality of photodiodes to be reselected in the event an eccentricity in data track position causes the primary area of interest to extend beyond the monitored plurality of photodiodes,
• velocity detection means including external clock means responsive to signals from at least one of said photosensitive elements for determining increases and decreases in the rotational velocity of said storage medium, and
• switching means responsive to said velocity detection means for selecting from said photosensitive elements at least one of said elements positioned so that the information to be retrieved is present at that element at the proper time as determined by said velocity detection means.

An electro-optical data retrieval system for retrieving data from a storage medium and of the type wherein relative motion is imparted between the recording medium and pickup means for causing said data to be scanned for retrieval thereof, comprising:

• means for receiving a data-bearing storage medium having a relatively high density of data tracks thereon,
• illuminance means for illuminating an area of said storage medium,
• detector means including a matrix array of photosensitive elements, said array having predetermined dimensions,
• focusing means for focusing an image of an area of interest within said illuminate area of said storage medium onto said detector means, the image of a data track being no smaller than a single photosensitive element, said array being dimensioned such that the area of interest does not extend beyond said array despite variations in the position of the area of interest with respect to the array due to variations in the location of the data relative to the detector means,
• select circuit means including means for selecting at least one of said photosensitive elements of said array to provide an output signal of the system, said means for selecting including register means for selecting at least one of said photosensitive elements,
• delay meams for delaying a signal representative of the same information from each of said photosensitive elements by a predetermined amount, said signal being provided at different times, and
• summing means for summing together the signals from each of said photosensitive elements, the amount of said delay being determined to cause each of said signals from said photosensitive elements to present at said summing means at substantially the same time, thereby increasing signal-to-noise ratio.

An electro-optical data retrieval system for retreiving data from a storage medium and of the type wherein relative motion is imparted between the recording medium and a pickup means for causing said data to be scanned for retrieval thereof, the position of the data being capable of variation relative to the pickup means, comprising:

• means for receiving a data-bearing storage medium having a relatively high density of data tracks thereon,
• illuminance means for illuminating at least an area of interest of said storage medium,
• focusing means,
• a matrix array of photosensitive elements, disposed relative to said storage medium such that said focusing means may focus an image of said area of interest onto said array of photosensitive elements, the image of a data track being no smaller than a single photosensitive element, said array being dimensioned such that the area of interest does not extend beyond the array even in the event the position of data in the area of interest varies relative to the array,
• current-sensing preamplifier means and select circuit means associated with said photosensitive elements, said select circuit means being for selecting at least one of the photosensitive elements through said preamplifier means to provide an output signal responsive to said image impinging upon said photosensitive elements,
• tracking means for detecting variations in the position of the data and thereby selecting the photosensitive element which provides the output signal in response to such variation,
• delay means for delaying a signal representative of the same information from each of said photosensitive elements by a predetermined amount, said signal being provided at different times, and
• summing means for summing together the signals from each of said photosensitive elements, the amount of said delay being determined to cause each of said signals from said photosensitive elements to present at said summing means at substantially the same time, thereby increasing signal-to-noise ratio.

An electro-optical data retrieval system for retrieving data from a relatively high density data storage medium and of the type wherein relative motion is imparted between the recording medium and a pickup means for causing said data to be scanned for the retrieval thereof, comprising:

• illuminance means for illuminating an area of said storage medium,
• detector means including a matrix array of photosensitive elements disposed in rows and columns, a plurality of said photosensitive elements in at least one of said rows being continually biased,
• focusing means for focusing an image of an area of interest within said illuminated area of said storage medium onto said detector means, said array being dimensioned such that the area of interest does not extend beyond such array,
• amplifier means for amplifying signals produced by a plurality of elements of said photosensitive array,
• select circuit means for selecting at least one of said amplified signals to be provided as an output signal, said select circuit including register means,
• delay means for delaying a signal representative of the same information from each of said photosensitive elements by a predetermined amount, said signal being provided at different times, and
• summing means for summing together the signals from each of said photosensitive elements, the amount of said delay being determined to cause each of said signals from said photosensitive elements to present at said summing means at substantially the same time, thereby increasing signal-to-noise ratio.

An electro-optical data retrieval system for retrieving data from a storage disc wherein relative rotational motion is imparted between the storage disc and a pickup means for causing the disc to be scanned for retrieval of the stored data therefrom comprising:

• means for receiving a storage disc having data stored thereon in data tracks,
• illuminance means on one side of the storage disc for flooding with radiation an area of the storage disc greater than a primary area of interest of at least one data track,
• detector means adapted for connection to processing circuitry including a matrix array of photodiodes located on the other side of the storage disc,
• focusing means between the storage medium receiving plane and the detector means for focusing an image of at least a primary area of interest of the storage medium caused by the illuminance means onto the detector means, the array size being greater than permissible eccentricities in data track position,
• monitor circuit means for monitoring a plurality of photodiodes in the matrix array which receive the image of the primary area of interest and selecting, in accordance with a predetermined criteria, one of the plurality to provide an output signal, the monitoring circuit means including means for causing the photodiodes included in the monitored plurality of photodiodes to be reselected in the event an eccentricity in data track position causes the primary area of interest to extend beyond the monitored plurality of photodiodes,
• delay means for delaying a signal representative of the same information from each of said photosensitive elements by a predetermined amount, said signal being provided at different times,
• summing means for summing together the signals from each of said photosensitive elements, the amount of said delay being determined to cause each of said signals from said photosensitive elements to present at said summing means at substantially the same time, thereby increasing signal-to-noise ratio.