INFORMATION DEVICE

1 . An information device comprising:

a head including a first element, a second element, and an inter-element distance varying unit configured to vary a distance between the first element and the second element in a direction orthogonal to a track direction on a surface of an information carrier, and

a head moving unit configured to move the head in parallel to the surface of the information carrier, wherein

the head moving unit and the inter-element distance varying unit cause the first element and the second element to respectively follow corresponding target tracks.

2 . The information device according to claim 1 , wherein the head moving unit and the inter-element distance varying unit cause the first element and the second element to follow tracks in different radial positions.

3 . The information device according to claim 2 , wherein the head moving unit and the inter-element distance varying unit cause the first element and the second element to follow tracks adjacent to each other in the direction orthogonal to the track direction.

4 . The information device according to claim 1 , wherein the head moving unit and the inter-element distance varying unit cause the first element and the second element to follow a same track.

5 . The information device according to claim 1 , wherein

the first element includes a recording element for recording information on the information carrier, and

the second element includes a reproducing element for reproducing the information from the information carrier.

6 . The information device according to claim 5 , wherein

the recording element irradiates a recording target area of the information carrier with near field light generated by Plasmon resonance with the recording target area to record information on the information carrier, and

the reproducing element reproduces the information from the information carrier by utilizing Plasmon resonance with a reproduction target area of the information carrier.

7 . The information device according to claim 5 , wherein the recording element and the reproducing element are arranged such that, when a recording operation or a reproducing operation is performed, the recording element reaches a position where information on the information carrier is recorded or reproduced and then the reproducing element reaches the position.

8 . The information device according to claim 7 , wherein the recording element and the reproducing element are arranged apart from each other by a distance equal to or larger than a distance determined on the basis of the number of revolutions of the information carrier and time from start to end of a change of a recording film of the information carrier at the time when the recording operation is performed.

9 . The information device according to claim 5 , further comprising a checking unit configured to reproduce, with the reproducing element, information recorded by the recording element in parallel to the recording operation to thereby check whether the recording by the recording element has been correctly performed.

10 . The information device according to claim 5 , wherein the recording element and the reproducing element are arranged such that, when a recording operation or a reproducing operation is performed, the reproducing element reaches a position where information on the information carrier is recorded or reproduced and then the recording element reaches the position.

11 . The information device according to claim 10 , wherein the recording element and the reproducing element are arranged apart from each other by a distance equal to or larger than a distance determined on the basis of the number of revolutions of the information carrier, and a total time of a reproduction delay time required for a reproducing signal to pass a reproducing signal transmission line through which the reproducing signal is transmitted, a circuit delay time required for processing the reproducing signal, and a recording delay time required for a recording signal to pass a recording signal transmission line through which the recording signal is transmitted.

12 . The information device according to claim 10 , further comprising an overwrite processing unit configured to record, with the recording element, information reproduced by the reproducing element in parallel to the reproducing operation to thereby overwrite information recorded on the information carrier.

13 . The information device according to claim 12 , further comprising:

a reproducing signal quality measuring unit configured to measure signal quality of a reproducing signal obtained when the information recorded on the information carrier is reproduced; and

a recording quality determining unit configured to reproduce, with the reproducing element, the information recorded on the information carrier, and determine recording quality of the information recorded on the information carrier on the basis of a measurement result from the reproducing signal quality measuring unit, wherein

when it is determined by the recording quality determining unit that the recording quality is poor, the overwrite processing unit records, with the recording element and in parallel to the reproducing operation, the information reproduced by the reproducing element in a position where the information is recorded on the information carrier to thereby overwrite the information recorded on the information carrier.

14 . The information device according to claim 5 , further comprising:

a recording track positional deviation detecting unit configured to detect a positional deviation between the recording element and the track; and

a reproducing track positional deviation detecting unit configured to detect a positional deviation between the reproducing element and the track.

15 . The information device according to claim 5 , further comprising:

a reproducing track positional deviation detecting unit configured to detect a positional deviation between the reproducing element and the track; and

a recording track positional deviation estimating unit configured to estimate a positional deviation between the recording element and the track on the basis of a signal from the reproducing track positional deviation detecting unit.

16 . The information device according to claim 15 , wherein the recording track positional deviation estimating unit estimates the positional deviation between the recording element and the track on the basis of a radial position of the information carrier where the head is located.

17 . The information device according to claim 5 , wherein

the head further includes an element for tracking arranged on a track same as the track of the recording element and near the recording element, and

the information device further comprises:

a recording track positional deviation detecting unit configured to detect a positional deviation between the element for tracking and the track; and

a reproducing track positional deviation detecting unit configured to detect a positional deviation between the reproducing element and the track.

18 . The information device according to claim 5 , further comprising:

a recording track positional deviation detecting unit configured to detect a positional deviation between the recording element and the track;

a recording abnormality detecting unit configured to detect whether an abnormality has occurred during a recording operation on the basis of a signal from the recording track positional deviation detecting unit during the recording operation; and

a following stopping unit configured to stop the reproducing element from following the target track when it is detected by the recording abnormality detecting unit that an abnormality has occurred during the recording operation.

19 . The information device according to claim 1 , wherein

the head further includes a magnetic recording element for magnetically recording information on the information carrier,

the first element includes an element for tracking,

the second element includes a heating element for heating a recording target area of the information carrier,

the element for tracking is arranged on a track same as the track of the magnetic recording element and near the magnetic recording element, and

the head moving unit and the inter-element distance varying unit cause the element for tracking and the heating element to follow a same track to thereby cause the magnetic recording element and the heating element to follow a same track.