Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
2000-09-21
2004-05-18
Nguyen, Huy (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C386S349000
Reexamination Certificate
active
06738562
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to optical disc playback apparatuses and, more specifically, to an optical disc playback apparatus for displaying, on a television screen, an on-screen message in the predetermined number of lines changeable to an image display format of data recorded on an optical disc being played back.
2. Description of the Background Art
Recently, video CD players which are CD players incorporated with MPEG1 (Moving Picture Coding Experts Group1) decoding feature are widely available. Such video CD players are capable of reproducing images and sounds for maximum of 74 minutes from moving picture data and audio data recorded on video CDs and Karaoke CDs, wherein such data is digitally compressed by MPEG1 technique. Further,CVDs (China Video CDs) and SVCDs (Super Video CDs) with higher quality of image and audio data are commercialized especially focusing on the Chinese market. The CVDs and the SVCDs are realized with MPEG2 (Moving Picture Coding Experts Group2) decoding featureinstead of MPEGI, and can be played back without any modification on mechanism such as optical pickup, servo technique, and signal processing technique for the MPEG1.
Mainly in the Japanese and US markets, DVD players incorporated with the MPEG2 decoding feature are commercialized. The DVD players are capable of reproducing maximum of 133 minutes of high-quality moving pictures with high-resolution defined by horizontally 702 dots and vertically 480 lines, together with high-quality sound. In addition to the higher quality of reproduced images and sounds, advanced features are achieved in these video CD players and DVD players. Such advanced features are quite convenient for sophisticated users who are familiar with such features to enjoy various functions. On the other hand, it is difficult for ordinary users due to complicated operation required to utilize the functions. To ease the user's inconvenience caused by the complicated operability, the video CD players and DVD players recently adopt an OSD (On-Screen Display) function. The function is for displaying information for user's easy operation on a monitor for reproduced pictures. Such information indicates input information corresponding to user's operation, an elapsed time after start of reproduction, a status of the player during reproduction, special reproduction function, and a type of optical disc. The information is referred to as an on-screen message (OSM).
Hereinafter, by referring to
FIGS. 10
,
11
, and
12
, examples of conventional optical disc playback apparatuses are described. In
FIG. 10
, a first example of the conventional optical disc playback apparatus is shown. In a conventional optical disc playback apparatus OPC
1
of this example, an optical disc Od, typically a music CD, is fixedly placed on a spindle motor
72
for rotation. An optical pickup
73
applies a laser beam Lb onto the recording surface of the rotating optical disc Od to read out data therefrom as digital signals.
An optical servo controller
74
executes a servo-control of the spindle motor
72
and the optical pickup
73
. A digital signal processor
75
demodulates the digital signals from the optical pickup
73
to convert the signals into sub-code information, control information, a sequence of CD-DA signals unique to the music CD, and a sequence of other signals. Based on the sub-code information and the control information supplied from the digital signal processor
75
, a system controller
76
determines the type of the optical disc being played back and detects system errors such as track jumps and focus errors of the laser beam Lb.
An information signal sequence separator
79
separates the digital signal sequences supplied from the digital signal processor
75
into the CD-DA signal sequence and the other signal sequence.
An MPEG1 decoder
78
receives the CD-DA signal sequence and the other signal sequence from the information signal sequence separator
79
. If the CD-DA signal sequence is received, the MPEG1 decoder
78
outputs the received signal sequence as it is by using memory
77
as buffer memory. On the other hand, if the signal sequence other than the CD-DA signal sequence is received, the MPEG1 decoder
78
reads disc information on the optical disc Od to determine whether the image display format of the video recorded thereon (signal sequence other than the CD-DA signal sequence) is the PAL or the NTSC.
Further, by using the memory
77
as buffer memory, the MPEG1 decoder
78
converts the video signal sequence (signal sequence other than the CD-DA signal sequence) in real time into a decoded digital signal sequence. Note that if the video is in the PAL format, the video signal sequence is converted into a decoded digital signal sequence in the PAL format. If the video is in the NTSC format, the video signal sequence is converted into a decoded digital signal sequence in the NTSC format.
An on-screen display controller
7
A converts character data and character display information from the system controller
76
into a digital character signal sequence.
A video signal D/A converter
7
B converts the decoded digital signal sequence from the MPEG1 decoder
78
and the digital character signal sequence from the on-screen display controller
7
A into analog video signals.
An audio signal D/A converter
7
C converts the CD-DA signal sequence from the MPEG1 decoder
78
into analog audio signals.
The playback operations of the optical disc playback apparatus OPC
1
are described with respect to a music CD and other type of optical disc, respectively. For playing back the music CD, the digital signal processor
75
starts demodulation of the digital signals and then outputs the control information and the sub-code information.
When the system controller
76
determines that the signal sequence is the CD-DA signal sequence based on the control information and the sub-code information, the system controller
76
judges that no video signal sequence is recorded on the optical disc Od. In such case, the system controller
76
transmits a control instruction instructing the digital signal processor
75
to output border color signals (normally blue-back) in the NTSC format instead of the video signals. The system controller
76
further outputs the character display information and the character data to the on-screen display controller
7
A.
The system controller
76
monitors the system errors such as track lumps and focus errors. Whenever such error occurs, the system controller
76
instructs the optical servo controller
74
so that the optical pickup
73
and the spindle motor
72
return to initial states thereof.
The MPEG1 decoder
78
receives the CD-DA signal sequence from the digital signal processor
75
and outputs the same by using the memory
77
as buffer memory. The MPEG1 decoder
78
also converts the border color signals in the NTSC format from the digital signal processor
75
into the decoded digital signal sequence.
The on-screen display controller
7
A receives the character display information from the system controller
76
, and sets the number of character display lines of an on-screen message to 10. The on-screen display controller
7
A further receives and converts the character data into the digital character signal sequence.
The video signal D/A converter
7
B converts the decoded digital signal sequence from the MPEG1 decoder
78
and the digital character signal sequence from the on-screen display controller
7
A into the analog video signals.
The audio signal D/A converter
7
C converts the CD-DA signal sequence from the MPEG1 decoder
78
into the analog audio signals.
Described next is the operation of the optical disc playback apparatus OPC
1
for playing back the optical disc Od other than the music CD. For playing back the optical disc Od, the digital signal processor
75
starts demodulation of the digital signals and then outputs the control information and the sub-code information as well as the signal sequence other than th
Matsushita Electric - Industrial Co., Ltd.
Nguyen Huy
Wenderoth , Lind & Ponack, L.L.P.
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