Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1996-10-08
2001-01-23
Chevalier, Robert (Department: 2715)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C386S349000
Reexamination Certificate
active
06178288
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a reproduction apparatus, and in particular to a VCR (video cassette recorder) for reproducing a digital signal or an analog signal.
2. Description of the Related Art
In recent years, VCRs for reproducing analog signals (such as VHS-VCRs and 8 mm-VCRs) have been made into commercial products. In addition, VCRs for reproducing digital signals have also been developed. Hereinafter, examples of such conventional reproduction apparatuses are described.
In a conventional reproduction apparatus for reproducing analog signals, a frequency multiplexed video signal recorded on a magnetic tape, which includes an FM (frequency modulated) luminance signal and a low-frequency conversion carrier chrominance signal, is reproduced by a magnetic head and then amplified by a video preamplifier. The output of the video preamplifier is separated into the FM luminance signal and the low-frequency conversion carrier chrominance signal components through a high pass filter and a low pass filter, respectively. A reproduced luminance process circuit subjects the FM luminance signal to a limiter process, a dropout compensation, an FM demodulation process, a de-emphasis, a deviation adjustment, a low-frequency filtering, and a noise cancellation process, thereby obtaining a reproduced luminance signal. On the other hand, a reproduced chrominance process circuit subjects the low-frequency conversion carrier chrominance signal to an AGC (automatic gain control) process, a burst de-emphasis, a frequency high-range conversion, and a color killer process, thereby restoring a reproduced carrier chrominance signal. Then, the reproduced luminance signal and the reproduced carrier chrominance signal are added by an adder so as to be output via an output terminal as a reproduced video signal.
On the other hand, an FM audio signal which is recorded on the magnetic tape by a multi-layer recording method is reproduced by a magnetic head, amplified by an audio preamplifier, and separated into a left FM audio signal and a right FM audio signal through band-pass filters. A reproduced FM audio signal process circuit subjects the left and right FM audio signals to a demodulation process, a dropout compensation, a low-frequency filtering, and a noise reduction process, so as to be output via an output terminal as a reproduced audio signal.
Thus, an analog video signal and an analog audio signal can be reproduced.
In a conventional digital signal reproduction apparatus, a signal recorded on a magnetic tape is reproduced by a magnetic head, amplified by a playback amplifier, and then input to a reproduced digital signal process circuit. The reproduced digital signal process circuit subjects the signal to a playback equalization, an AGC process, a channel decoding, a decoding for error correction codes, and an error correction process, thereby outputting a reproduced digital signal via an output terminal. The reproduced digital signal is, for example, an MPEG (Moving Picture Experts Group) signal which is obtained by compressing video image data and audio data in accordance with the MPEG standards. By processing the signal with an MPEG decoder, video and audio output signals can be obtained.
Thus, a digital signal can be reproduced.
In the field of home-use VCRs, the recording/reproduction of analog signals (e.g., by the VHS method) is currently predominant. However, once digital broadcasting or the like is commenced in the future, it will require a VCR which is capable of recording digital signals. Therefore, by accommodating both the above-mentioned analog signal process circuitry and the above-mentioned digital signal process circuitry, it becomes possible for one VCR to reproduce both analog signals and digital signals. Moreover, for simplifying mechanical components and for improved usefulness, the cassette tape for recording digital signals can be adapted to have substantially the same shape and size as those of the cassette tape for recording analog signals, thereby making it possible to reproduce both analog signals and digital signals from one cassette tape.
However, such conventional reproduction apparatuses typically record or reproduce digital signals and analog signals in a mingled manner in the same (or same kind of) cassette tape. As a result, when reproducing a recorded signal, it is impossible to determine whether a digital signal or an analog signal is recorded, so that it cannot be determined whether to operate the digital signal process circuitry or the analog signal process circuitry of the reproduction apparatus.
SUMMARY OF THE INVENTION
A reproduction apparatus according to the present invention includes: a signal reading section for reading a signal recorded on a recording medium, the signal including a digital signal and an analog signal; a control signal reading section for reading a control signal recorded on the recording medium and including information representing a time mode indicating a run speed of the recording medium; a first determination section for determining the time mode based on an output of the control signal reading section; and a second determination section for determining whether the signal read by the signal reading section is a digital signal or an analog signal after the time mode is determined by the first determination section.
In one embodiment of the invention, the reproduction apparatus further includes an unrecorded mode determination section for determining whether or not the signal is recorded on the recording medium based on the output of the control signal reading section.
In another embodiment of the invention, the second determination section includes a digital signal detection section for outputting a digital signal detection signal when detecting that the signal read by the signal reading section is a digital signal.
In still another embodiment of the invention, the digital signal detection section keeps operating regardless of whether the signal read by the signal reading section is a digital signal or an analog signal.
In still another embodiment of the invention, the second determination section includes an analog signal detection section for outputting an analog signal detection signal when detecting that the signal read by the signal reading section is an analog signal.
In still another embodiment of the invention, the analog signal detection section keeps operating regardless of whether the signal read by the signal reading section is a digital signal or an analog signal.
In still another embodiment of the invention, the second determination section includes: a digital signal detection section for outputting a digital signal detection signal when detecting that the signal read by the signal reading section is a digital signal; and an analog signal detection section for outputting an analog signal detection signal when detecting that the signal read by the signal reading section is an analog signal.
In still another embodiment of the invention, the recording medium includes a digital signal recorded region in which the digital signal is recorded, an analog signal recorded region in which the analog signal is recorded, and an unrecorded region in which the signal is not recorded, the control signal including information representing only one time mode for the digital signal, and the second determination section determines, when a region read by the control signal reading section proceeds from a first region to a second region, whether or not the signal read by the signal reading section is the analog signal based on the control signal read in the second region, the first region being the digital signal recorded region and the second region being different from the first region.
In still another embodiment of the invention, the recording medium includes a digital signal recorded region in which the digital signal is recorded, an analog signal recorded region in which the analog signal is recorded, and an unrecorded region in which the signal is not recorded, the control s
Kunihira Tadashi
Yanagawa Yoshifumi
Chevalier Robert
Kelly Michael K.
Matsushita Electric - Industrial Co., Ltd.
Snell & Wilmer LLP
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