# US 5,349,735 A · Information detection apparatus and displacement information measurement apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,735 A - Document ID: US5349735A - Status: Granted - Kind: A - Application number: 08/132,161 - Filed: 1993-10-05 - Granted: 1994-09-27 - Earliest claimed: 1990-07-09 - Assignees: Canon Kabushiki Kaisha - Inventors: Toshimitsu Kawase; Akihiko Yamano; Ryo Kuroda; Hiroyasu Nose; Toshihiko Miyazaki - Web page: https://patentgrep.com/patent/US5349735A ## CPC - G01B 7/003: {for measuring position, not involving coordinate determination (coordinate measuring G01B7/004)} - G11B 9/14: using microscopic probe means {, i.e. recording or reproducing by means directly associated with the tip of a microscopic electrical probe as used in Scanning Tunneling Microscopy [STM] or Atomic Force Microscopy [AFM] for inducing physical or electrical perturbations in a recording medium; Record carriers or media specially adapted for such transducing of information (marking using electrical current B41M5/20; measuring roughness or irregularity of surfaces G01B7/34; details of scanning-probe microscopes G01Q)} - G11B 9/1409: {Heads} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - G01Q 70/06: Probe tip arrays - G01Q 80/00: Applications, other than SPM, of scanning-probe techniques (manufacture or treatment of nanostructures B82B3/00; recording or reproducing information using near-field interaction G11B9/12, G11B11/24, G11B13/08) - Y10S 977/874: Probe tip array - Y10T 29/49764: with testing or indicating - Y10T 29/49771: Quantitative measuring or gauging - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - G01Q: SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM] - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An information detection apparatus is disclosed. A plurality of probes are arranged in the apparatus so as to face a medium which carries an information, Each of the plurality of probes produces a detection signal from the medium. A performance testing device is provided in the apparatus for testing the performance of each of the plurality of probes. A detection device in the apparatus selects the signal from at least one normal probe on the basis of the test result of the testing device and detects the information in accordance with the selected signal. By such the construction in the apparatus, the detection of the information can be continuously effected even if one of the probes is broken. ## Claims ### Claim 1 An apparatus for detecting information from an information bearing medium, comprising: a plurality of probes arranged to face the medium, each of said probes producing a detection signal from the medium; performance test means for testing a signal producing condition of each of said probes; and detection means for selecting a detection signal from at least one of the probes having a predetermined signal producing condition based on a test by said performance test means and detecting the information in response to the selected detection signal. ### Claim 2 (depends on 1) An apparatus for detecting information from an information bearing medium according to claim 1, wherein said probes are arranged to face scale means of the medium for imparting information on a length of the medium, and said detection means detects relative displacement information of said probes with respect to said scale means as said information. ### Claim 3 (depends on 2) An apparatus for detecting information from an information bearing medium according to claim 2, wherein said probes are arranged to face a plurality of identical scale means formed for respective probes. ### Claim 4 (depends on 1) An apparatus for detecting information from an information bearing medium according to claim 1, wherein said performance test means tests the signal producing condition of respective ones of the plurality of probes based on the signals produced from the respective ones of the plurality of probes. ### Claim 5 (depends on 1) An apparatus for detecting information form an information bearing medium according to claim 1, wherein said probes produce signals due to tunneling currents flowing between said probes and the medium as the detection signals. ### Claim 6 (depends on 1) An apparatus for detecting information from an information bearing medium according to claim 1, wherein said detection means detects the information in response to a signal from the at least one of said probes having the predetermined signal producing condition when a physical defect is detected in one of said probes by said performance test means. ### Claim 7 (depends on 1) An apparatus for detecting information from an information bearing medium according to claim 1, wherein said detection means detects the information in response to a signal from a predetermined one of said probes when a physical defect is not detected in any of said probes by said performance test means. ### Claim 8 (depends on 1) An apparatus for detecting information from an information bearing medium according to claim 1, wherein said detection means detects the information in response to a mean value of the signals produced by said probes when a physical defect is not detected in any of said probes by said performance test means. ### Claim 9 (depends on 1) An apparatus for detecting information from an information bearing medium according to claim 1, further comprising repairing means for repairing a probe having a physical defect detected by said performance test means. ### Claim 10 (depends on 9) An apparatus for detecting information from an information bearing medium according to claim 9, wherein said repairing means includes position control means for bringing the probe having the physical defect detected to face a probe reproducing station and reproducing means for repairing the probe brought to face the probe reproducing station, and said position control means controls the position of the probe repaired by said reproducing means to face the medium. ### Claim 11 An apparatus for detecting displacement information between two objects based on information from a scale imparting a positional reference, comprising: a plurality of probes formed on one of said two objects other than an object having scales formed thereon, said probes being arranged to face respective scales and said probes producing detection signals from the scales; a performance test circuit for testing a signal producing condition of said probes; and a signal processing circuit for selecting a detection signal from at least one of said probes having a predetermined signal producing condition based on the test by said performance test circuit and detecting the displacement information of the two objects in response to the selected detection signal. ### Claim 12 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, wherein said performance test circuit tests the signal producing condition of respective ones of the plurality of probes based on signals produced from the respective ones of the plurality of probes. ### Claim 13 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, wherein said probes produce signals due to tunneling currents flowing between said and a medium as the detection signals. ### Claim 14 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, further comprising an actuator for vibrating said probes laterally with respect to the scales; said performance test circuit testing the signal producing condition of said probes based on the signals from said probes vibrated by said actuator. ### Claim 15 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, further comprising an actuator for vibrating said probes laterally with respect to the scales; said signal processing circuit detecting the displacement information of the two objects based on a signal produced by a probe having the predetermined signal produced condition vibrated by said actuator. ### Claim 16 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, wherein said signal processing circuit detects the displacement information of the two objects in response to a signal from a probe having the predetermined signal producing condition when a physical defect is detected in one of the probes by said performance test circuit. ### Claim 17 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, wherein said signal processing circuit detects the displacement information of the two objects in accordance with a signal from a predetermined one of said probes when a physical defect is not detected in any of said probes by said performance test circuit. ### Claim 18 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, wherein said signal processing circuit detects the displacement information of the two objects in response to a mean value of the signals produced by said probes when a physical defect is not detected in any of said probes by said performance test circuit. ### Claim 19 (depends on 11) An apparatus for detecting displacement information between two objects according to claim 11, further comprising a repairing mechanism for repairing a probe having a physical defect detected by said performance test circuit. ### Claim 20 A method for detecting information from an information bearing medium, comprising the steps of: arranging a plurality of probes to face the medium; detecting signals from the medium by the probes; testing a signal producing condition of each probe; selecting a detected medium signal from at least one of the probes having a predetermined signal producing condition based on the testing of the signal producing condition of the probes; and detecting the information in response to the selected detected medium signal. ### Claim 21 (depends on 20) A method for detecting information from an information bearing medium according to claim 20, wherein the step of arranging the plurality of probes includes arranging the plurality of probes to face scale means of the medium to impart information on length of the medium, and the step of detecting information includes detecting relative displacement information of the probes with respect to the scale. ### Claim 22 (depends on 20) A method for detecting information from an information bearing medium according to claim 20, further comprising the step of repairing a probe having a physical defect based on the testing of the signal producing condition of the probes. ### Claim 23 An apparatus for transferring information between a medium and a probe, comprising: performance test means for testing a signal producing condition of a plurality of probes arranged to face the medium; and transfer means for selecting at least one of the probes having a predetermined signal producing condition based on the test by said performance test means and transferring the information int he medium with the selected probe. ### Claim 24 (depends on 23) An apparatus for transferring information between a medium and a probe according to claim 23, wherein said transfer means detects information on a length from the medium by the at least one of said probes having the predetermined signal producing condition. ### Claim 25 (depends on 23) An apparatus for transferring information between a medium and a probe according to claim 23, further comprising means for repairing a probe having a physical defect based on the test by said performance test means.