Television – Two-way video and voice communication – Conferencing
Reexamination Certificate
1999-12-02
2002-04-09
Kuntz, Curtis (Department: 2643)
Television
Two-way video and voice communication
Conferencing
C348S014080, C348S014100
Reexamination Certificate
active
06369846
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multipoint television conference system having conference terminals disposed at a plurality of locations and a multipoint controlling unit (hereinafter, referred to as MCU) that mixes audio signals of the individual locations that are received from the individual conference terminals, distributes the mixed audio signal to the individual conference terminals, combines a video signal from the individual video signals that are received from the individual conference terminals corresponding to a selection signal, and distributes a combined video signal to the individual conference terminals.
2. Description of the Prior Art
A conventional multipoint television conference system is composed of one MCU and a plurality of conference terminals. When a conference attendee speaks to an assigned conference terminal, the speech is transmitted as an audio signal to the MCU.
Each conference terminal has an audio/video signal transmitting/receiving/transferring function, a video displaying function, and an audio outputting function. The MCU mixes audio signals received from conference terminals with each other and distributes the mixed audio signal to conference terminals. When each conference terminal transmits a video signal to the MCU, the MCU selects a video signal of one conference terminal. Alternatively, the MCU may combine video signals received from two or more conference terminals, distribute the combined video signal to each conference terminal and cause each conference terminal to display the combined video signal.
Next, with reference to
FIG. 1
, a conventional television conference system will be described.
FIG. 1
is a block diagram showing the structure of the conventional television conference system. Referring to
FIG. 1
, the television conference system has a plurality of conference terminals
16
a
to
16
c
and one MCU
17
. In this example, it is assumed that three people have a conference using respective conference terminals
16
a
to
16
c.
The conference terminals
16
a
to
16
c
convert video signals and audio signals of respective locations (A) to (C) into transmission signals and transmit the transmission signals to the MCU
17
through communication lines
1671
a
to
1671
c,
respectively. The MCU
17
processes the video signals and audio signals in a particular manner that will be described later and distributes the resultant signals to the conference terminals
16
a
to
16
c.
The MCU
17
comprises a line interface portion
171
, an audio processing portion
172
, a controlling portion
173
, a video processing portion
174
, and a speaking attendee determination processing portion
175
.
The line interface portion
171
is connected to a plurality of conference terminals
16
a
to
16
c.
The line interface portion
171
transmits and receives video signals and audio signals as transmission signals. The audio processing portion
172
and the video processing portion
174
are connected to the line interface position
171
through connection lines
7172
and
7174
, respectively.
The audio processing portion
172
decodes audio signals received from the conference terminals
16
a
to
16
c
and supplies the decoded signals to the speaking attendee determination processing portion
175
through a connection line
7275
. The speaking attendee determination processing portion
175
determines a speaking attendee corresponding to the received audio signal and supplies the determined result as speaking attendee information to the controlling portion
173
through a connection line
7573
.
The controlling portion
173
generates a video control signal for an image switching process and an image combining process with the input speaking attendee information and supplies the video control signal to the video processing portion
174
through a connection line
7374
. In addition to the video control signal, video signals of individual conference terminals are supplied from the line interface portion
171
to the video processing portion
174
through the connection line
7174
. The video processing portion
174
performs the image switching process, the image combining process, and so forth for the video signals corresponding to the video control signal. The video processing portion
174
encodes video signals and supplies the encoded video signals to the line interface portion
171
through the connection line
7174
.
The audio processing portion
172
mixes the audio signals received from the conference terminals
16
a
to
16
c,
encodes the mixed signal, and supplies the encoded signal to the line interface portion
171
. The line interface portion
171
multiplexes the processed audio signals and the processed video signals and distributes the multiplexed signal to all the conference terminals
16
a
to
16
c
through the connection lines
1671
a
to
1671
c.
Next, with reference to
FIG. 2
, the internal structure of the speaking attendee determination processing portion
175
will be described. Referring to
FIG. 2
, the speaking attendee determination processing portion
175
has audio volume detecting portions
175
a
to
175
c.
The audio volume detecting portions
175
a
to
175
c
receive audio signals from the audio processing portion
172
through connection lines
110
a
to
110
c,
respectively. The audio volume detecting portions
175
a
to
175
c
compare the audio volumes of the audio signals with a predetermined threshold value and transmits the comparison results as speaking attendee determination information to a speaking attendee determining portion
14
through connection lines
7114
a
to
7114
c,
respectively.
When an audio volume is equal to or higher than the predetermined threshold value in any of audio volume detecting portions
175
a
to
175
c,
the speaking attendee determining portion
14
determines that the conference terminal corresponding to the volume detecting portion has a speaking attendee. When the audio volume is lower than the predetermined threshold value in all of audio volume detecting portions
175
a
to
175
c,
the speaking attendee determining portion
14
determines that the conference terminals have no speaking attendees.
When a plurality of conference terminals have speaking attendees, the speaking attendee determining portion
14
determines that the conference terminal which has the longest time period in which an audio volume is equal to or larger than the predetermined threshold has a speaking attendee. The determined result is output as speaking attendee information to the controlling portion
173
through a connection line
7573
.
In the conventional television conference system, the speaking attendee determination information is detected from audio signals received from the conference terminals. Generally, in addition to a voice of a conference attendee, an audio signal contains noise such as a page turning noise, a desk knocking noise, and a breathing noise. Moreover, when a conference is held at a place where there are many people, their voices may be contained in an audio signal. In this case, voices of other than conference attendees become noises.
Thus, the speaking attendee determination signal detected from audio signals may include errors. Consequently, it was difficult to accurately determine a conference terminal that has a speaking attendee in the prior art. If a conference terminal that has a speaking attendee is incorrectly determined, it is difficult to smoothly manage a television conference system.
SUMMARY OF THE INVENTION
In order to overcome the aforementioned disadvantages, the present invention has been made and accordingly, has an object to provide a television conference system which accurately determines conference terminals each having a speaking attendee without being disturbed by noises.
According to an aspect of the present invention, there is provided a multipoint television conference system, comprising: terminals, and a multipoint control unit for controlling the terminals, wherei
Kuntz Curtis
NEC Corporation
Ostrolenk, Faber, Gerb & Soffen, LL
Ramakrishnaiah Melur
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