An apparatus and method for recording and/or reproducing information onto/from a medium through a probe electrode. A voltage is applied between the medium and the probe electrode and a distance between the medium and the probe electrode is adjusted in such a manner that current becomes a predetermined current value, the current flowing to the probe when the voltage is applied between the medium and the probe electrode. The predetermined current value is changed in accordance with the voltage being applied.

An image reader uses a film having a magnetic information recording section. An image entry section reads a photographic image captured on a film and digitizes it. A setting section sets at least one imaging condition selected from the integration time, gradation conversion characteristic, and resolution of the image entry section as control information. A magnetic writing section writes the control information set by the setting section onto the magnetic information recording section of the film. A magnetic reading section reads the control information from the magnetic information recording section. A control section is responsive to the control information read by the reading section to control the image entry section.

A tracking mechanism for an apparatus which records and/or reproduces data on and/or from a medium through a relative scan of the medium with probes, the medium being formed with a plurality of tracking bit trains disposed in parallel at a predetermined distance between trains, the tracking mechanism having: a plurality of probes disposed at a predetermined distance between probes; and a tracking controller for performing a tracking control in accordance with outputs from the plurality of probes, the outputs being obtained when the plurality of tracking bit trains are scanned with the plurality of probes. A tracking method for such an apparatus includes the steps of: scanning the plurality of tracking bit trains with a plurality of probes disposed at a predetermined distance between probes; and performing a tracking control in accordance with outputs from the plurality of probes, the outputs being obtained when the plurality of tracking bit trains are scanned with the plurality of probes.

Electrical data is recorded and retrieved by producing and detecting impedance change. A layer of high resistivity material on a conductive substrate is used as the recording layer. A conductive probe pressing on it is used for sending writing or reading electrical current flowing in a direction normal to its surface. A large enough electrical voltage pulse is applied on this probe, causing electro-forming in a data spot in the recording layer under the probe, turning the local resistance of this data spot from high to low. This change in resistance or more generally, change in impedance, is utilized to write data. Several kinds of impedance detecting circuits, utilizing the principle of voltage divider circuit or field effect transistors are employed in data reading. A large number of writing/reading units can be integrated compactly.

An information recording and/or reproducing apparatus for recording and/or reproducing information to/from a recording medium in a scanning probe microscope comprises a circuit to reproduce recording bits formed on the recording medium on the basis of a physical amount such as tunnel current, interatomic force, electrostatic force, or magnetic force which occurs between the probe and the recording medium, a sensor to detect a state such as film thickness or film quality of the recording medium on the basis of the physical amount before the recording bits are reproduced, and a correcting circuit to correct reproducing conditions such as a magnitude of a voltage which is applied between the probe and the medium on the basis of the detected state of the medium.