Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism – Controlling the head
Reexamination Certificate
1995-07-19
2001-01-30
Sniezek, Andrew L. (Department: 2753)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
Controlling the head
C360S051000
Reexamination Certificate
active
06181506
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tracking control device and, more particularly, to a device for causing a head to trace a track which is formed on a recording medium and on which a digital signal is recorded.
2. Description of the Related Art
Reproduction tracking systems for domestic-use video tape recorders or video cassette recorders fall into two major systems. The first system is called “CTL system”. In the CTL system, a fixed magnetic head is provided at a particular location in a tape path. During recording, a predetermined control signal (CTL signal) is recorded on a dedicated track, and, during reproduction, a reproducing head is made to trace a track by using the CTL signal reproduced from the dedicated track. The second system is called “ATF system”. In the ATF system, during recording, a plurality of (normally, four) kinds of pilot signals having comparatively low frequencies are recorded simultaneously with a main signal (normally, a video signal) in multiplexed form in such a manner that the frequencies are recurrently repeated from track to track. During reproduction, a tracking error signal (ATF error signal) is obtained by making a comparison between the frequency of the pilot signal reproduced from a track simultaneously with the main signal and the pilot signals reproduced from both adjacent tracks by crosstalk, and a reproducing head is made to trace the track on the basis of the tracking error signal.
In recent years, higher image quality and digitization have been increasingly demanded even in the field of domestic-use video tape recorders, and research and development have been conducted as to formats of narrower track pitch so that more information can be recorded and reproduced. In the case of reproduction from a narrow-pitch track, it is extremely important to increase the accuracy of the longitudinal linearity of the track. For example, in the case of a track of 10-&mgr;m pitch, the linearity must be held at 3 &mgr;m or less. This value is close to the limit of mechanical precision and offers great problems in terms of productivity and cost.
There is also a known art provided with an actuator for displacing a rotary head in a direction which intersects the rotating direction thereof. According to this art, even if a track is curved to some extent, the rotary head can be made to trace the curvature. Although the art is effective in improving tracking performance, it is necessary to use an extremely expensive rotary drum having a very complicated structure.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to solve the above-described problems.
Another object of the present invention is to provide a tracking control device having a high tracking capability with respect to the non-linearity of a track.
To achieve the above-described objects, according to one aspect of the present invention, there is provided a tracking control device which comprises reproducing means for reproducing digital information from a recording medium, detecting means for detecting an error in the reproduced digital information, and tracking control means for controlling a relative position between the recording medium and the reproducing means by using an output of the detecting means.
According to another aspect of the present invention, there is provided a tracking control device which comprises reproducing means for reproducing digital information from a recording medium, forming means for forming a plurality of tracking error signals indicative of positional deviations between the reproducing means and a plurality of divided areas into which each track formed on the recording medium is divided, and tracking control means for controlling a relative position between the recording medium and the reproducing means by selectively using the plurality of tracking error signals.
The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4486796 (1984-12-01), Sakamoto
patent: 4688109 (1987-08-01), Sangu
patent: 4977469 (1990-12-01), Yokozawa
patent: 5233487 (1993-08-01), Christensen et al.
patent: 5287225 (1994-02-01), Sukigara
patent: 5654843 (1997-08-01), Hatanaka
Shimura Yukio
Takayama Nobutoshi
Yamashita Shinichi
Canon Kabushiki Kaisha
Robin Blecker & Daley
Sniezek Andrew L.
LandOfFree
Tracking control device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tracking control device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tracking control device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441247