U.S. patent application number 10/346379 was filed with the patent office on 2003-10-02 for sound processing unit, sound processing system, audio output unit and display device.
This patent application is currently assigned to Hitachi, Ltd.. Invention is credited to Kabuto, Nobuaki, Yoshioka, Atsushi, Yoshizawa, Kazuhiko.
Application Number | 20030185400 10/346379 |
Document ID | / |
Family ID | 28449660 |
Filed Date | 2003-10-02 |
United States Patent
Application |
20030185400 |
Kind Code |
A1 |
Yoshizawa, Kazuhiko ; et
al. |
October 2, 2003 |
Sound processing unit, sound processing system, audio output unit
and display device
Abstract
The present invention identifies practical speaker connection
using a device having a sound channel of a 5.1 channel or 7.1
channel, and provides the device that can easily reproduce the
optimum multiple channels. The present invention can identify
actual speaker arrangement by for example, measuring the impedance
of a terminal at the side of an audio amplifier. If incorrect
connection is found, a warning is issued. This information is
transmitted to a signal source with an EDID and a signal with the
optimum a number of sound channel is sent. The EDID is also used
for the connection with a display unit and the speaker connection
with which the display unit is provided uniquely. For example, a
sound through the 7.1 channel is easily reproduced using the
speaker of the display unit in the channel of the front
speaker.
Inventors: |
Yoshizawa, Kazuhiko;
(Yokohama, JP) ; Kabuto, Nobuaki; (Kunitachi,
JP) ; Yoshioka, Atsushi; (Ebina, JP) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Hitachi, Ltd.
Tokyo
JP
|
Family ID: |
28449660 |
Appl. No.: |
10/346379 |
Filed: |
January 15, 2003 |
Current U.S.
Class: |
381/58 ;
381/74 |
Current CPC
Class: |
H04R 5/02 20130101; H04N
5/607 20130101; H04R 3/12 20130101; H04R 5/04 20130101; H04N
21/43615 20130101; H04R 2205/024 20130101; H04N 21/485 20130101;
H04N 21/4882 20130101; H04R 2420/05 20130101 |
Class at
Publication: |
381/58 ;
381/74 |
International
Class: |
H04R 029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2002 |
JP |
2002-093545 |
Claims
What is claimed is:
1. A sound processing unit which receives a sound signal including
a plurality of sound channels from a sound signal source, processes
the input sound signal, and supplies the processed sound signal to
a connected speaker or headphone, comprising: a state storage unit
that stores a connected state of the speaker or headphone, and the
state storage unit storing a detection result of a detection
circuit for detecting whether the speaker or headphone is connected
or not, a user setting or any setting of their combinations; and a
control circuit for sending information dependent on the connected
state of the speaker or headphone to the sound signal source based
on the storage of the state storage unit.
2. The sound processing unit according to claim 1, wherein the
detection circuit detects the speaker connection by measuring
electrical impedance of an output terminal.
3. A sound processing system that is provided with a sound signal
source and a sound processing unit which receives a sound signal
including a plurality of sound channels from the sound signal
source, and processes the input sound signal, and supplies the
processed signal to a connected speaker or headphone, comprising: a
state storage unit that stores a connected state of the speaker or
headphone, and the state storage unit storing a detection result of
a detection circuit for detecting whether the speaker or headphone
is connected or not or, a user setting or any setting of their
combinations; and a control circuit for sending information
dependent on a number of sound channel that corresponds to a
connected number of the speaker or headphone to the sound signal
source, based on the storage of the state storage unit.
4. The sound processing system according to claim 3, wherein the
sound signal source receives the information about the number of
sound channel output from the sound processing unit and generates a
sound signal of the number of sound channel that corresponds to the
information, then supplies it to the sound processing unit.
5. The sound processing system according to claim 3, wherein the
sound signal source sends a video signal with a sound signal, and
the sound processing unit supplies the video signal to a display
device.
6. The sound processing unit according to claim 1, wherein the
sound processing unit receives a video signal with a sound signal
from the audio signal source, and is incorporated in a display
device for displaying the video signal from the audio output
unit.
7. A sound processing unit for processing a video signal and a
sound signal including a plurality of sound channels and supplying
the video signal to a display device, then supplying the sound
signal to a speaker, comprising: a sound multiplex circuit for
multiplexing the sound signal of the number of sound channel that
corresponds to the speaker number belonging to the display device,
with the video signal, then supplying the multiplexed signal to the
display device.
8. The sound processing unit according to claim 7, wherein a
headphone connection terminal and a headphone detection circuit are
provided in the sound processing unit and the transmitting a sound
signal to the display device is stopped according to a detection
result of the headphone detection circuit.
9. A sound processing unit for processing a video signal and a
sound signal of plural sound channels and supplying the video
signal to a display device, then supplying the sound signal to a
speaker, comprising: a first detection circuit for detecting
whether the speaker is connected to a speaker connection terminal
of the sound processing unit or not; a second detection circuit
that detects the speaker belonging to the display device; and a
sound multiplex circuit that performs sound processing of the sound
signal including a plurality of input sound channels in accordance
with detection results of the first and second detection circuits
and multiplex the sound signal equal or below the number of sound
channel in accordance with the detection result of the second
detection circuit, then supplies the multiplexed signal to the
display device.
10. The sound processing unit according to claim 9, wherein if it
is detected by the first detection circuit that a speaker is not
connected to a speaker connection terminal of a specific channel,
the sound multiplex circuit multiplex a sound signal of the
specific channel with the video signal and reproduces the sound
signal of the specific channel by the speaker belonging to the
display device.
11. The sound processing unit according to claim 9, wherein if it
is detected by the first detection circuit that a speaker is
connected to a speaker connection terminal of a specific channel,
the sound multiplex circuit lowers a level of a sound signal of the
specific channel rather than usual and multiplexes the sound signal
with the video signal or stops to multiplex the sound signal of the
specific channel with the video signal.
12. The sound processing unit according to claim 9, wherein the
multiplex circuit multiplex the sound signal of the front right
(FR) channel and front left (FL) channel, and/or the center (C)
channel with video signal, if the input sound signal is the 5.1
channel.
13. The sound processing unit according to claim 9, wherein if it
is detected by the first detection circuit that a speaker of a
first group is connected to the speaker connection terminal, the
sound multiplex circuit multiplex a sound signal of a second group
with the video signal.
14. The sound processing unit according to claim 13, wherein the
first group is the front right (FR) channel, the front left (FL)
channel, and the center (C) channel and the second group is the
front right center (FRC) channel and the front left center (FLC)
channel, if the input sound signal is the 7.1 channel.
15. The sound processing unit according to claim 9, further
comprising: an OSD (on screen display) for supplying a visual
message regarding a speaker connected state to the user using a
detection result by the first detection circuit; the OSD (on screen
display) circuit which provides the visual message about the state
of speaker connection; and an addition circuit that overlap the OSD
circuit output on an input a video signal or switches from input
video signal to the OSD circuit output and supplies it to the video
signal display device.
16. A display device in which receives a video signal and a sound
signal from a signal source processes the input video and sound
signal, displays the processed video signal on the display device
and supplies the processed sound signal to a speaker or a
headphone, comprising: a state storage unit that stores a detection
result of a detection circuit for detecting an connected state of
the speaker or headphone, a user setting about an operation of the
speaker or head phone, or their combinations; and a control circuit
for sending information about the connected state of the speaker or
headphone to the signal source based on the information of the
state storage unit.
17. A display device that processes and displays a video signal
output from an external sound processing unit to which a speaker is
connected, comprising: a headphone connection terminal and a
headphone detection circuit; and a control circuit that sends a
detection result of the headphone detection circuit to the external
sound processing unit.
18. A sound processing unit that receives a signal from a sound
signal source, processes and outputs this signal, comprising: a hot
plug function for posting that the sound processing unit is
connected to the sound signal source; a plug and play function that
transmits the configuration of the sound processing unit to the
sound signal source; and a function that allows the sound
processing unit requests the sound signal source for starting a
plug and play function as a reconnected state after the sound
processing unit disconnects the connection with the sound signal
source when the configuration of the sound processing unit changes,
wherein if the sound processing unit identifies that the sound
signal source can respond to even short-time disconnection for the
indication of the starting the hot plug function, the disconnection
state is for a short period of time in comparison with the case
where it is not identified.
19. A display device that displays an image and reproduces a sound,
comprising: a hot plug function for posting that the display device
is connected to a video signal source; a plug and play function
that transmits the configuration information of the display device
to the video signal source; and a function that allows the display
device to request the video signal source for starting a plug and
play function as a reconnected state after the display device
disconnects with the video signal source when the configuration of
the display device changes, wherein if the display device
identifies that the video signal source can respond to even
short-time disconnection for the indication of the starting the hot
plug function, the disconnection state is for a short period of
time in comparison with the case where it is not identified.
20. A device provided with a circuit that processes a sound signal,
comprising: an OSD (On Screen Display) circuit for providing the
user with a menu screen including a plurality of choices regarding
a number of a sound channel of a sound signal to be reproduced; and
a signal generation circuit that generates a control signal for
controlling the cannel number of the sound signal based on the
number of sound channel which is selected by the user from the menu
screen displayed by the OSD circuit.
21. The device according to claim 20, further comprising: a channel
number control circuit that controls a number of sound channel of a
sound signal based on a control signal from the signal generation
circuit.
22. The device according to claim 20, wherein the menu screen
includes a message to connect a speaker to the device when the
speaker is not connected to the device.
23. An apparatus that reproduces a sound by receiving a television
broadcasting signal having a video signal, a sound signal, and
program information that includes program type, comprising: a
memory that stores data of a number of sound channel of a sound to
be reproduced corresponding to a program type respectively; a read
circuit that reads the data of the channel number of the sound to
be reproduced corresponding to the data regarding the program type
included in the received program information from the memory; and a
channel number control circuit that controls the number of sound
channel of the sound signal to be reproduced corresponding to the
data of the number of sound channel of the sound read from the read
circuit.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an art for clearly
reproducing sound signals of multiple channels (for example, 5.1
channel and 7.1 channel) obtained from television broadcasting or a
storage device, such as a VCR (Video Cassete Recorder), a DVD
(Digital Versatile Disc), and a hard disc recorder. The present
invention is especially applied to a broadcasting receiving unit
(hereinafter referred to as an STB (set-top-box)) that receives the
television broadcasting and outputs a sound signal and a video
signal, a sound signal source (needless to say, the video signal
can also be output), a sound processing unit, such as a switcher,
for processing a signal from this sound signal source and
distributing the signal to multiple speakers, or a display device,
such as a television receiver.
[0003] In the television broadcasting and package media, such as
movie software products, the digitalization of video and sound
signals is advancing. The realization of multiple channels in a
digital sound signal advances. For example, in some DVD sounds,
what is called, a sound of the 5.1 channel in which five channels
of the front left (FL), the front right (FR), the center (C), the
rear left (RL), and the rear right (RR) and a sub woofer (S) for
reproducing a low-pitched sound are combined can be reproduced.
Further, a sound of the 7.1 channel including the front left center
(FLC) and the front right center (FRC) is also reproduced.
[0004] When the realization of multiple channels of a sound signal
advances in this manner, the connection of a speaker cable becomes
complicated and there is a possibility of incorrect connection. As
a first prior art for simplifying the connection work of many
speakers, for example, the art described in Japanese Patent
Laid-Open No. 2001-25085 is generally known. It is disclosed in
this literature that when a speaker of the 5.1 channel is
connected, the arrangement of the speaker is judged with a test
signal output from the speaker, and inappropriate arrangement and
connection are posted if they are found, and at the same time the
connection with the speaker is switched by an audio amplifier.
[0005] As a second prior art, for example, the art described in
Japanese Patent Laid-Open No. H10(1998)-94086 is known. It is
disclosed in this literature that a terminal not connected to a
speaker is detected and a sound signal to be supplied to the
speaker is allocated to another speaker.
SUMMARY OF THE INVENTION
[0006] In the aforementioned first prior art, however, a method of
automatically taking action only by a warning indication was not
suggested when some speakers are not connected to a sound signal
processing unit. For example, even if a switcher with an audio
amplifier that is one of sound signal processing units corresponds
to a 5.1 channel, there is a possibility of a sound effect becoming
unsatisfactory when the user does not perform appropriate
processing.
[0007] In a second prior art, processing is performed
automatically, and a manual instruction for sound processing is not
required. In the second prior art, however, sound signal allocation
processing is performed only in the audio amplifier. Accordingly,
for example, even when a sound signal source connected to an audio
amplifier cannot identify a speaker number connected to the audio
amplifier, and when multiple sound signals such as a stereophonic
sound system and the 5.1 channel can be supplied, an appropriate
sound signal cannot be supplied.
[0008] Further, it was not taken into consideration in the
aforementioned first and second prior arts that even a speaker
originally installed in a display device, such as a television
receiver, is utilized, and a display unit of a display device is
utilized when the speaker is connected.
[0009] The present invention is made in consideration of the
aforementioned problems. An object of the present invention is to
provide an art for transmitting a connected state of a speaker
connected to a sound processing unit to a sound signal source and
requesting sound data suitable for the connected state, and
enabling the reproduction of a sound suitably. Further, the present
invention provides an art that enables the reproduction of more
excellent sound by utilizing even a speaker installed in a display
device. Moreover, the present invention provides such an art that
can easily check the connection of a complicated multi-channel
speaker utilizing the display unit of the display device.
[0010] To achieve the aforementioned object, the present invention
is provided with a detection circuit that detects a connected state
of a speaker for each output terminal of a sound signal that
corresponds to multiple sound channels and a control circuit for
sending information about the connected state of the speaker, for
example, to a sound signal source, such as an STB, in a sound
signal processing unit, such as a switcher unit. The configuration
of this sound processing unit can also be provided in a display
device, such as a television receiver.
[0011] The sound signal source receives the information about the
connected state of the aforementioned speaker and controls a number
of sound channel supplied to the sound processing unit based on the
input information.
[0012] Specifically, the aforementioned sound processing unit, if
it is detected by the aforementioned detection circuit that the
speakers of specific channels (for example, the front right (FR)
channel and the front left (FL) channel, and/or the center (C)
channel) are not connected ought also be configured so that the
sound signals of these specific channels can multiplex with video
signals and reproduced by the speaker that belongs to the display
device.
[0013] Further, to connect a speaker, it is desirable that an OSD
(On Screen Display) circuit is provided, and a visual message
regarding the connected state of the speaker should be supplied to
the user through this OSD circuit using a detection result by the
detection circuit. This message ought also to include the
information that indicates the incorrect connection of a speaker
and the presence of the speaker connection, for example. Further,
to display the arrangement of the speaker by the aforementioned OSD
circuit and issue a test sound signal to each speaker, an
indication for visually judging the speaker under test ought also
to be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a device block diagram showing an embodiment of
the present invention;
[0015] FIG. 2 is a device block diagram showing another embodiment
of the present invention;
[0016] FIG. 3 is a device block diagram showing another embodiment
of the present invention;
[0017] FIG. 4 is a block diagram of a signal source and a switcher
used in the present invention;
[0018] FIG. 5 is another block diagram of the signal source and the
switcher used in the present invention;
[0019] FIG. 6 is a block diagram of a display unit used in the
present invention;
[0020] FIG. 7 is a drawing showing a display example in the display
unit used in the present invention;
[0021] FIG. 8 is another drawing showing the display example in the
display unit used in the present invention;
[0022] FIG. 9 is a device block diagram showing another embodiment
of the present invention;
[0023] FIG. 10 is a block diagram of the signal source and a
built-in signal source switcher used in the present invention;
[0024] FIG. 11 is another block diagram of the signal source and
the switcher used in the present invention; and
[0025] FIG. 12 is another block diagram of the display unit used in
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Embodiments of the present invention are described below
with reference to the drawings. FIG. 1 is a device block diagram
showing an embodiment of the present invention. The device of this
embodiment has a display device 1, a sound reproducing apparatus 2,
and a signal source 3. The display device 1 and the sound
reproducing apparatus 2 are mutually connected through an
audiovideo signal transmission line 231 including a plug and play
function. This transmission line may also be an interface with
sound transmission line and video transmission line like DVI 1.0
(Digital Visual Interface version 1.0) established by the DDWG
(Digital Display Working Group) that is the connection
specification between a PC (Personal Computer) itself and a display
device. Further, the transmission line may also be an interface for
multiplexing a digital video signal and a digital sound signal.
[0027] Besides, in the following explanation of this embodiment,
the "plug and play function" allows a signal sending unit to grasp
characteristic data of a signal receiving unit without personal
assistance and to automatically send the optimum signal to the
signal receiving unit when the signal sensing unit and the signal
receiving unit are connected with a cable.
[0028] The embodiment of the present invention is devised so that a
speaker in a state in which it can function practically can be
posted to an audiovideo signal source. Further, when a state of
speaker connection changes, the embodiment is devised so that the
audiovideo signal source can identify this state and the audio
output suitable for a new state can be obtained even in
operation.
[0029] First, a switcher 201 measures the impedance of a load in
each terminal to which speaker cables 220 to 225 are connected and
detects the presence of speaker connection. Such a strict
measurement is not necessary only for the presence, but even a
method of providing a signal source having output impedance and
roughly measuring a voltage that appears in a terminal is
acceptable. Further, for example, because a sub woofer 210 is a
special speaker that reproduces a low-pitched sound, it is designed
to be different in internal impedance from another speaker.
Otherwise, if high frequency impedance is reduced by connecting
between input terminals using a capacitor, the type of the speaker
as well as the presence of the connection can be judged and
incorrect connection can be detected.
[0030] Besides, as described later, because the system of the
present invention is characterized by having a display unit 101,
the detected speaker connection is shown in the display unit, and a
warning can be indicated if there is an incorrect connection.
Further, for example, although the RL (rear left) speaker is
connected in the speakers at the rear side, the RR (rear right)
speaker is not connected. At this occasion, this indication warns
that RR speaker is not connected. Moreover, a message indicating
that a signal in which the RL and RR speakers are added is output
from the RL speaker side can also be posted.
[0031] Further, for example, when a speaker is connected to the 5.1
channel, the layout drawing of a typical speaker is displayed on
the display unit 101 and a test signal is sent to every speaker.
Simultaneously, even the layout error of the speaker can simply be
identified by having a function that displays the speaker on the
display unit, such as blinking, and lets the user to check whether
there is a conflict with a direction where a sound comes
practically.
[0032] Subsequently, after a speaker to which the switcher 201 is
connected practically is detected, the configuration for posting
this speaker to audiovideo signal sources 301, 302 is described.
This is performed to implement the plug and play function by adding
information about speaker connection to an EDID (Extended Display
Identification Data) established by the VESA (Video Electronics
Standards Association) as an identifier, for example. This EDID
shows the specifications (a supportable horizontal frequency range
and a pixel number) of a display device. That information about the
connected state of the speaker is added to this EDID signal and
posted to the audiovideo signal sources 301, 302.
[0033] A switcher sends an EDID according to a request of an
audiovideo signal source. If the switcher have detected a speaker
previously, it sends the EDID which have been rewritten from the
initial speaker arrangement to the practically connected speaker.
Further, if the EDID has already been sent before the speaker is
detected, the connection between the switcher 201 and the
audiovideo signal sources 301, 302 are disconnected once using a
hot plug function and a new EDID is resent after the speaker is
detected. For this purpose, the information whether the EDID has
already been sent or not, may be also stored in a RAM (Random
Access Memory) or such. Besides, the hot plug function originally
indicates whether a sound reproducing apparatus and an audiovideo
signal source are connected with a cable. Because short
disconnection time, such as dozens of milliseconds, may fail to
detect desirably, the disconnection time should be approximately
0.5 to 2 seconds if accurate operation is taken into consideration.
A device function is interrupted in this disconnection time. IF a
hot plug line is prepared independently, a virtual disconnection
which only hot plug line is disconnected and an audiovideo
transmission line keep to connect, is available. This virtual
disconnection technique provides seamless transmission of video and
sound signals can also continue.
[0034] Against the case where there is no hot plug function, it is
still more convenient that an audiovideo signal source should be
provided with a function of cyclically reading EDID every
predetermined time, for example, approximately 0.5 to 2
seconds.
[0035] Subsequently, the audiovideo transmission line 231 with a
plug and play function is described. The case where neither FR
speaker 211 or FL speaker 212 is connected nor found is taken into
consideration with reference to the device block diagram of FIG. 2.
The speaker marked by oblique lines in the diagram is connected by
a speaker cable. The speaker cables 221, 222 are drawn by a dashed
line in the diagram, and not connected as marked by an X mark.
These two speakers 211, 212 are indispensable for obtaining a sound
field with a correct ambience. Accordingly, when the aforementioned
switcher 201 with an audio amplifier detects that these speakers
are not connected, the switcher 201 sends sound signals for the FR
and FL channels to the display unit 101, thereby to reproduce a
sound by a front-right speaker 111 and a front-left speaker 112 of
the display unit.
[0036] This can eliminate defects caused by missing the front main
speakers. The switcher 201 can identify whether a speaker is
connected to the display unit 101 or not by reading an EDID
transmitted via the audiovideo transmission line 231. For that
purpose, The display unit 101 should have a function of detecting
whether the aforementioned speaker is connected practically or not.
Besides, when the FR speaker 211 and the FL speaker 212 are
connected, the front-right speaker 111 and the front-left speaker
112 of the display unit need not be used. In this case, the
switcher 201 should send mute data or the sound signal whose level
lowers rather than usual ought to be sent, or stop to send a sound
signal to the display unit 101.
[0037] Further, as described previously, it is easily understood
for the user to display the layout drawing of the speaker shown in
FIG. 2 in the display unit 101 at device startup and display the
presence of each speaker connection. For this purpose, an OSD (On
Screen Display) circuit for displaying a drawing and a character
ought to be provided in the switcher 201.
[0038] In the example of FIG. 2, if a sound of the 5.1 channel is
generated from the audiovideo signal source 301 or 302, the sound
of the 5.1 channel can be reproduced using the speakers 111, 112 of
the display unit. Accordingly, when it is detected that the
speakers 211, 212 are not connected, the guidance as shown
typically in FIG. 7, on the display unit 101 may be useful.
[0039] Even if the speakers 211, 212 of the FR and FL channels are
connected as a modification of the aforementioned item, when the
central speaker 210 of the C channel is not connected, the switcher
201 sends a sound signal of the C channel and ought also to be able
to reproduce a sound by the front-right speaker 111 and the
front-left speaker 112 of the display unit or either of them.
Accordingly, a sound field with an ample ambience can be obtained
using the speaker of the display unit 101.
[0040] At present, the sound of the 5.1 channel that uses the FR,
FL, C, RR, RL, and S channels can be reproduced using a DVD. In the
future, however, to increase the ambience, the sound of the 7.1
channel to which the two channels of the front right center (FRC)
channel and the front left center (FLC) channel are added are
assumed to be used. If the speakers of the FR and FL channels are
connected, the sound of the 7.1 channel ought to be reproduced by
using the speaker of the display unit that is easily located nearer
to the center than these speakers in the FRC and FLC channels. The
switcher 201 detects using the aforementioned method that the
speaker of the 5.1 channel is connected. Further, the switcher 201
detects an EDID transmitted via the audiovideo transmission line
231 and identifies that the speaker is connected to the display
unit 101. Further, when the sound signal of the 7.1 channel is sent
from the audiovideo signal source 301 or 302, the sound signals of
the FRC and FLC channels among them are sent to the display unit
101 via the audiovideo transmission line 231. Besides, when the
signal of the 7.1 channel can be reproduced in the aforementioned
manner, if the sound signal from the audiovideo signal source 301
or 302 belongs to the 5.1 channel, for example, the switcher 201
ought also to perform matrix operation and artificially produce the
signals of the FRC and FLC channels, then send them to the display
unit 101.
[0041] Besides, when the speakers 111, 112 of the aforementioned
display unit 101 are utilized, the sound signals supplied to these
speakers can be sent by the audiovideo transmission line 231
together with video signals through this single transmission line.
Accordingly, a speaker cable need not be drawn around every speaker
and wiring is simplified.
[0042] Subsequently, the case where only the speaker 211 of the FR
channel is not connected is taken into consideration with reference
to the device block diagram of FIG. 3. Needless to say, a sound
field with a normal ambience is not obtained as it is. At this
occasion, after the switcher 201 detects that the speaker 211 is
not connected, the menu shown typically in FIG. 8 ought also to be
displayed. The user selects a number in the drawing, using a remote
controller, for example. In FIG. 8, when 1 is selected, a sound is
reproduced by a 2-channel stereophonic sound system using the
speakers 111, 112 connected to the display unit (monitor). When 2
is selected, the sound is reproduced through the 5.1 channel using
the speakers 111, 112 as the main speakers together with the
speakers 210, 213, 214, 215 without using the speakers 211, 212.
When 3 is selected, the sound is reproduced through the 5.1 channel
using the speakers 211 to 215 assuming that the user connects the
speaker 211. Further, when 4 is selected, the sound is reproduced
through the 7.1 channel using the speakers 111, 112, 211 to 215
assuming that the user connects the speaker 211. The sound can be
reproduced in accordance with the selection of the user.
[0043] These menu display and menu selection are convenient because
they also work as countermeasures for incorrect operation of a
speaker connection detection circuit when they can start at an
optional timing according to a user instruction, for example, using
a remote controller as well as when the speaker connection
detection circuit detects a change of speaker arrangement. Further,
they ought also to be performed according to only the user
instruction without providing a speaker connection detection
circuit in a switcher.
[0044] If a gain for a sound signal differs between the display
unit 101 and the switcher 201 with an audio amplifier, a correct
ambience cannot be reproduced. For this purpose, it is assumed that
the gain value is standardized and adjusted. In the present
circumstances, however, this standard is not available, and this
standardization is not easy especially between the devices of
different manufacturers. Because a remote controller is usually
placed near by the user, a method of incorporating a microphone in
this remote controller, generating a sound by every speaker,
detecting this sound, and controlling a gain so that an optimum
balance can be obtained is assumed. Further, there is also a method
of requesting the user for the optimum adjustment by generating a
sound, such as by issuing an instruction that indicates speaker
arrangement in the display unit 101 and making the relevant speaker
blink. Further, there is also a method of estimating the speaker
arrangement by operating the speaker other than a speaker to be
tested as microphone.
[0045] For example, when the sound of the 7.1 channel is reproduced
using the speakers 111, 112, as described previously, it is also
assumed that the power of the display unit 101 is disconnected
halfway in a program consisted of only music. In this case, a a
number of sound channel to be output ought to be switched so that
the sound of the 7.1 channel can be reproduced when the power of
the display unit 101 turns on and the sound of the 5.1 channel can
be reproduced when the power turns off. As to whether the power of
the display unit 101 turns on or not, there is a method of
detecting the retransmission of an EDID signal indicating speaker
non-connection via the audiovideo transmission line 231 using a hot
plug function and of detecting an operating state of an audiovideo
input circuit of the display unit 101 by the switcher 201 via the
audiovideo transmission line 231. When the switcher 201 identifies
that the power of the display unit is or was disconnected, the
switcher 201 ought also to convert a sound to the 5.1 channel by
matrix operation and send it to the respective speakers 210 to 215.
Further, after the connection between the audiovideo signal source
301 or 302 and the switcher 201 is disconnected once using the
aforementioned hot plug function, a new EDID ought also to be sent
and received. The audiovideo signal source 301 or 302 sends a
sounds which is converted to the 5.1 channel. As a result, a sound
that is always suitable for a speaker state can be reproduced.
[0046] Besides, desirably, the switching that uses a hot plug
function should estimate the time of approximately 0.5 to 2 seconds
if the compatibility when a device of a different manufacturer is
used is taken into consideration, and the device cannot function in
the meantime. If both of the devices are machine types of the same
manufacturer, the switching in a shorter time can be performed when
it is confirmed that the devices are of the machine types
corresponding to the hot plug operation in a short time. Because a
internal control signal is sometimes sent in the vertical blanking
period of a video signal, the disconnection time by the hot plug
operation can be set below the conventional three frames
(approximately 200 ms) by interlace scan even if an operation
margin is taken into consideration. Accordingly, an effect that the
disconnected time can be reduced is gained.
[0047] Further, when a speaker is connected after starting to
reproduce sounds, a sound cannot be reproduced from the relevant
speaker as is. A newly connected speaker can also function by
operating the hot plug function according to a user instruction,
loading a result from which the aforementioned speaker connection
was detected newly on an EDID, and sending and receiving it between
devices.
[0048] The block diagram of each component for realizing the
aforementioned item is described with reference to FIG. 4, FIG. 5,
and FIG. 6. FIG. 4 and FIG. 5 show the switcher 201 with an audio
amplifier and the audiovideo signal source 301 (or 302)
respectively, and FIG. 6 shows the display unit 101.
[0049] First, the details are described with reference to FIG. 4.
The audiovideo signal source 301 is composed of a video signal
source 30101, a sound signal source 30102, a sound multiplex
circuit 30103, a transmitter 30104, and a channel number control
circuit 30105. Besides, an audiovideo transmission line 331 with a
plug and play function for connection with the switcher 201 is
practically a single bundle cable, but divided into 331A and 331B
and shown for convenience sake of explanation.
[0050] The video signal source 30101 sends video signal obtained
from television broadcasting or a device, such as a DVD, to the
sound multiplex circuit 30103. The sound signal source 30102 sends
sound signal accompanied by this video signal to the sound
multiplex circuit 30103 in the same manner. A number of sound
channel from the sound signal source 30102 is determined according
to the instruction of the channel number control circuit 30105.
This number of sound channel may also be controlled by extracting
the necessary number of sound channel from sound data contained in
the television broadcasting or a device such as a DVD. Further,
conversion of decreasing a number of sound channel as the need
arises or conversion of increasing the mumber of sound channel by
producing a signal artificially may also be performed. The
instruction of this number of sound channel is determined with an
EDID sent from the switcher 201 as described later. The video
signal and sound signal multiplexed through the sound multiplex
circuit 30103 are sent to the switcher 201 via the transmitter
30104.
[0051] Subsequently, the switcher 201 with an audio amplifier is
composed of a switch 20101, a receiving circuit 20102, a sound
separator 20103, an adding circuit 20104, an audio output circuit
20105, a speaker connection detector 20106, a controller 20107, an
OSD circuit 20108, a first EDID generation circuit 20109, a second
EDID generation circuit 20110, a switch 20111, and a sound
multiplex circuit 20112. Further, the audiovideo transmission line
231 with a plug and play function for connection with the display
device 1 is practically a single bundle cable, but divided into two
lines and shown for convenience sake of explanation. The speaker
cables 220 to 225 are independent in the same manner as FIG. 1
respectively.
[0052] The signal sent from the audiovideo transmission line 331A
with a plug and play function to the switcher 201 with an audio
amplifier is first assigned to the switch 20101. This switch is
used for the aforementioned plug and play function. For example,
when an EDID is sent to post its own state between the devices at
device power startup or when speaker connection is detected in
operation and it is detected that the connection was changed, then
the EDID is sent, the switch 20101 is opened once (approximately up
to 2 seconds). The opening and closing timing is assigned from the
controller 20107. The switch is closed at normal use and an
audiovideo signal is assigned to the receiving circuit 20102.
Besides, the open circuit of the switch 20101 is shown typically.
If at least there is an open circuit or a level change in a hot
plug terminal, the sending and receiving operation of the
audiovideo signal can continue. A hot plug function may be realized
a hot plug line independent from an audiovideo transmission
line.
[0053] Subsequently, a video signal and a sound signal are
separated through the sound separator 20103. The former is assigned
to the adding circuit 20104 and the latter is assigned to the audio
output circuit 20105. Further, a number of sound channel of the
sound signal received practically is posted to the controller
20107. The audio output circuit 20105 ought also to correspond to
the 7.1 channel, for example, but, here, corresponds to the 5.1
channel in the same manner as FIG. 1.
[0054] The speaker connection detector 20106 according to the
present invention is provided in the output of each channel and
detects the presence of connection by measuring the impedance of a
speaker connection terminal. In accordance with the result, the
controller 20107 judges the number of sound channel of a sound most
suitable for being reproduced and gives an instruction to the
switch 20111. An EDID that can specify the optimum sound channel is
selected from the first EDID generation circuit 20109 and the
second EDID generation circuit 20110 and sent to the audiovideo
signal source 301. Needless to say, EDID are not limited to 2
types, but multiple EDID ought also be selected. Multiple whole
EDID data need not be provided, but only multiple EDID data
regarding a a number of sound channel ought also be prepared and
switched.
[0055] Further, to display the characters as shown previously in
FIG. 7 and FIG. 8 and display the connection drawing as shown in
FIG. 2 and FIG. 3, the controller 20107 sends an instruction to the
OSD circuit 20108 and generates a necessary display signal, then
assigns the signal to the addition circuit 20104. The signal is
here added to or substituted for a video signal from the sound
separator 20103. Besides, while display is being performed through
the OSD circuit 20108, if information that is currently being
broadcast is received, this information ought also be overlapped
and displayed as a background image. When a reproduction image,
such as an image obtained from a DVD is transmitted, however, this
reproduction operation ought also to stop temporarily. The output
of the addition circuit 20104 is assigned to the sound multiplex
circuit 20112.
[0056] To reproduce a sound using the speakers 111, 112 of the
display device 1 as shown in the embodiments of FIG. 2 and FIG. 3,
the aforementioned controller 20107 gives an instruction to the
sound multiplex circuit 20112 and multiplex a necessary 1- or
2-channel sound signal with a video signal, then sends it to the
display device 1. A sound signal selects only the C channel or the
FR and FL channels in accordance with the connected speaker number
of the display device 1. Further, in the case of the 7.1 channel,
the FRC and FLC channels may also be selected or the FRC and FLC
channels may artificially be produced and sent from the sound
signal of the 5.1 channel.
[0057] FIG. 4 shows an example in which a signal is fetched in
parallel from a part of speaker connection terminals and input to
the sound multiplex circuit 20112, but the output of the sound
separator 20103 ought also be input directly to the sound multiplex
circuit 20112. The speaker connection terminal is mostly an analog
signal, and, therefore, this terminal is advantageous when the
sound separator 20103 and the sound multiplex circuit 20112 handle
digital data. In FIG. 10 described later, the output of the sound
separator 20103 ought also to be input to the sound multiplex
circuit 20112 via the sound selector 20205.
[0058] Besides, whether the speaker of the display device 1 is
connected practically or not is transmitted to the controller 20107
as EDID by similar means on the side of the display device 1 as
described later. The controller 20107 determines an instruction to
the aforementioned sound multiplex circuit 20112 based on these
means.
[0059] FIG. 5 shows a block diagram in which the practical speaker
connection is detected in the present invention, but a function of
positively utilizing the speaker of the display device 1 is
omitted. The sound multiplex circuit 20112 is omitted (from FIG. 5)
in comparison with FIG. 4.
[0060] FIG. 6 is a block diagram showing an embodiment of the
display unit 101 in the present invention. Because the
configuration of FIG. 6 is the same as the switcher 201 of FIG. 4
and. FIG. 5 except that a display portion 10112 is provided and a
sound signal is assigned to two speakers 111, 112, a detailed
explanation is omitted. FIG. 6 is characterized by having a speaker
connection detection circuit 10106 for detecting whether the
speaker having the display unit 101 is connected practically and
being capable of receiving the optimum sound signal as described
previously by sending the result to a control circuit and
generating an EDID that posts a practically connected state to the
switcher 201. The configuration of FIG. 6 is the same as the
aforementioned switcher 201 regarding that a switch 10101 for a
plug and play function is provided and the EDID signal generation
circuit is not limited to two.
[0061] In the aforementioned explanation, as illustrated as an
EDID-RAM 20206 in FIG. 10 described later, if the EDID signal
generation circuit consists of a RAM (random access memory) or a
flash RAM and the contents are rewritten by a control circuit
composed of a CPU and such, a single generation circuit can further
generate many types of signals.
[0062] Subsequently, another embodiment of the present invention is
described with reference to the device block diagram of FIG. 9. The
point that differs from FIG. 1 is that the switcher 201 with an
audio amplifier of FIG. 1 is divided into another component, such
as an audio amplifier 202 and a switcher 203, in FIG. 9. In this
case, regarding the audiovideo transmission line 231 with a plug
and play that supplies a signal to the display unit 101, if this
line is connected to the switcher 203, the same operation as FIG. 1
is enabled. Further, the speakers 210 to 215 are connected to the
audio amplifier 202 via the speaker cables 220 to 225 in the same
manner as FIG. 1. Accordingly, the switcher 203 has a function of
allocating a signal from the audiovideo signal sources 301, 302.
The switcher not only sends a video signal to the display unit 101,
but also, as shown in the embodiment in which each channel of a
sound signal is described previously, is divided into the audio
amplifier 202 and the display unit 101 and sent in accordance with
the practically connected state of the speaker.
[0063] Operation varies with whether a sound transmission line 232
to which the audio amplifier 202 and the switcher 203 are connected
has a plug and play function or not. First, when a function is
provided, this function is newly implemented between the audio
amplifier 202 and the switcher 203. Another function is the same as
FIG. 1. On the other hand, if the function is not provided, the
user posts the speaker connected to the audio amplifier 202
practically to a device. For example, a method of inputting a
channel that is connected using a remote controller or changing a
display unit into a touch panel type one, issuing an indication as
shown in FIG. 2, and entering data by touching the mark of the
connected speaker is assumed.
[0064] Besides, in each embodiment, the case where there are two
speakers having the display unit 101 is described as an example.
Even if one or three speakers are provided, the present invention
can apply to them, and multiple-channel sound reproduction can be
realized using these speakers in the same concept as the
description of the present invention.
[0065] Subsequently, another embodiment of the present invention is
described with reference of the device block diagram of FIG. 10.
The case where an audiovideo signal source, such as a DVD, an STB
and so on, are incorporated in the switcher 201 with an audio
amplifier of FIG. 1 is assumed. In FIG. 10, 20201 is a video signal
source, 20202 is a sound signal source, 20203 is a video signal
selector, 20204 is a sound signal selector, 20205 is a sound
selector, and 20106 is an EDID-RAM. The same component as shown in
FIG. 4 is shown assigning the same number to it.
[0066] In FIG. 10, the EDID-RAM 20206 is used, but, as described in
the explanation of FIG. 4, the same operation as the case where the
multiple EDIDs of FIG. 4 are switched is performed. Further, the
sound selector 20205 is provided. A sound signal transmitted from
the output of the sound separator 20103 to the display device 1 is
extracted and sent to the sound multiplex circuit 20112. Basically,
however, the operation is the same operation as FIG. 4. Because the
same operation as FIG. 4 is performed to the external signal source
301 in particular, an explanation of operation is omitted.
[0067] When the switches 20203 and 20204 select the video output of
the internal video signal source 20201 and the audio output of the
internal sound signal source 20202, EDID data need not be sent and
received. A controller 20107 directly controls (not shown) the
sound signal source 20202 and sets the optimum a number of sound
channel of a sound to be reproduced. Because another operation is
the same operation as the external signal source 301, it is
omitted.
[0068] Subsequently, another embodiment of the present invention is
described with reference to the device block diagram of FIG. 11. In
the diagram, a headphone terminal is provided in the switcher 201
with an audio amplifier of FIG. 1. In FIG. 11, 226 is a headphone
cable that connects the headphone terminal (not shown) and the
headphone of the switcher 201 and 20207 is a headphone detector.
The same component as shown in FIG. 10 is shown assigning the same
number to it. The basic operation is omitted because it is the same
as FIG. 10, and only the headphone connection operation is
described below.
[0069] When a headphone is connected to a headphone terminal, the
headphone detector 20207 detects the connection of the headphone by
opening and closing a mechanical contact or detecting the impedance
detection of the headphone. A headphone detection signal is input
to the audio output circuit 20105 and the sound selector 20205 and
stops (mutes) the audio output to the speaker cables 220 to 225 and
the audio output to the sound multiplex circuit 20112.
Consequently, the audio output of the speaker connected to the
switcher 201 and all the speakers connected to the display device 1
can be stopped. To stop the sound connected to a display device,
there is also a method of sending a control signal to the display
device so that the sound volume of the display device 1 can be
reduced except that the input of the aforementioned sound multiplex
circuit 20112 is muted.
[0070] Hereupon, for example, if it is assumed that the speaker
arrangement of the 5.1 channel is used before a headphone is
connected, a number of sound channel of a sound to be reproduced,
such as the connected headphone is stereophonic or monaural, is
decreased. The change of this number of sound channel rewrites the
speaker arrangement information of the EDID-RAM 20206 via the
controller 20107 and is posted to the signal source 301 using the
hot plug function of the switch 20101. Simultaneously, the signal
source 301 outputs sound data suitable for a headphone.
[0071] Subsequently, another embodiment of the present invention is
described with reference of the block diagram of the display unit
of FIG. 12. In the drawing, a headphone terminal is provided in the
display unit 101 of FIG. 1. In FIG. 12, 123 is a headphone cable to
which the headphone terminal (not shown) and the headphone of the
display unit 101 are connected. Numeral 10113 is a headphone
detection circuit and 10114 is an EDID-RAM. The part in which the
EDID-1 and EDID-2 of FIG. 6 are switched by the switch 10111 is
substituted for the EDID-RAM in the same manner as the example of
FIG. 10. In addition, even the same component as shown in FIG. 6 is
shown assigning the same number to it. The basic operation is
omitted because it is the same as FIG. 6, and only the headphone
connection operation is described below.
[0072] When a headphone is connected to a headphone terminal, the
headphone detection circuit 10113 detects the connection of the
headphone by opening and closing a mechanical contact or detecting
the impedance of the headphone. A headphone detection signal is
input to the audio output circuit 20105 and the sound selection
circuit 10105 and stops (mutes) the audio output to the speaker
cables 121, 122. Consequently, the audio output of the speaker
connected to the display unit 101 can be stopped.
[0073] Hereupon, for example, when it is assumed that a speaker is
not connected before a headphone is connected, a sound reproduction
function is added by connecting the headphone This change rewrites
the speaker arrangement information of the EDID-RAM 10114 via
control 10107 and is posted to a sound processing unit (not shown),
such as an audio output unit and a switcher, using the hot plug
function of the switch 20101. A display unit receives sound data
suitable for a headphone and a sound is reproduced by the
headphone. Further, if the sound processing unit connected to the
audiovideo transmission line 231 with a plug and play function is
an audio amplifier to which speakers are connected, the audio
output of these speakers need to be stopped at the same time.
Accordingly, the speaker arrangement information of the
aforementioned EDID-RAM can be posted to the audio amplifier when
it is rewritten.
[0074] Further, if the dedicated control line and remote controller
are used jointly though they are not shown, a speaker can be muted
by directly controlling an audio amplifier. The method of jointly
using the control line and the remote controller is effective when
a stereophonic speaker cannot be distinguished from a stereophonic
headphone. In this case, if the stereophonic headphone is
connected, the speaker arrangement of the EDID-RAM is identical
when the stereophonic speaker is connected to the display unit
101.
[0075] In the explanation of the aforementioned embodiment, the
switcher 201 is separated from the audiovideo signal source 301 or
302 or the display device 1, but even the configuration in which
the audiovideo signal source 301 or 302 or the display device 1 is
incorporated in the switcher 201 ought to be acceptable. In this
case, the configuration in which connection information is sent
from the switcher 201 to the audiovideo signal source 301 or 302 is
omitted, but the configuration of number of sound channel control
that corresponds to the detected connected state is identical with
that of the aforementioned embodiment.
[0076] Further, when a television broadcasting signal has program
information, a number of sound channel ought also be controlled
based on the program information. Program information is used to
display an electronic program guide on a display. This program
usually indicates a schedule of a program in the future of each
channel. Further, program information includes a program title, a
name (number of sound channel) of a broadcasting station,
broadcasting start and end times of a program, types (movie, news,
and drama) of the program, and data regarding the number of sound
channel of a sound reproduced in the program.
[0077] The broadcasting signal of news program usually has the
sound signal of the 2 channel. The broadcasting signal of movie and
music program often have the sound signal of the 5.1 channel or 7.1
channel. Accordingly, the data indicating that the number of sound
channel is the 2 channel may be added to the broadcasting signal of
news, and the data indicating that the number of sound channel is
5.1 channel or 7.1 channel may be added to the broadcasting signals
of movie and music programs.
[0078] Accordingly, as another embodiment of the present invention,
the sound signal source 30102 ought also be controlled in a channel
number control circuit by extracting program information from the
broadcasting signal of the program selected by the user in
accordance with the data of the number of sound channel contained
in the extracted program information. Accordingly, when a news
program is selected and the data indicating that the number of
sound channel is the 2 channel is added to the broadcasting signal,
a sound is reproduced through the 2 channel even if a device is
provided with the speaker of the 5.1 channel. On the other hand,
when a movie program is selected and the data indicating that the
number of sound channel is the 2 channel is added to the
broadcasting signal, and the device is provided with the speaker of
the 5.1 channel, the sound is reproduced by utilizing all speakers.
Such configuration can realize automatic control of the number of
sound channel in accordance with the contents of the program.
[0079] Moreover, in the present invention, if the program with 2
channel audio signal is indicated as a "movie" program information
which the program contains, the program can be reproduced
artificially through the 5.1 channel. Further, if the program with
7.1 channel audio signal is Indicated as "news" in a program
information in which the program contains, the program can be
reproduced artificially through the 2 channel. That is, this
embodiment is characterized by using the data of the program type
more preferentially than the number of sound channel data contained
in program information as data for determining a number of sound
channel of a sound to be reproduced.
[0080] More specifically, the audiovideo signal source 301
including a receiver of a television broadcasting signal reproduces
a sound through the 5.1 channel or 7.1 channel when the program
information indicates a "movie". The source 301 reproduces a sound
through the 2 channel when the program information indicates
"news". For these function, a table is constructed by presetting
the data of the appropriate number of sound channel of a sound to
be reproduced every program type. The data table is used to set the
number of sound channel of a sound to be reproduced. The
aforementioned table can be stored in a microcomputer memory or
another memory that is not shown. The audiovideo signal source 301
(built-in microcomputer) extracts program information from the
received television broadcasting signal and judges the contents of
the data of a program type contained in the program information.
The judgment result is referred to with the table stored in the
aforementioned memory and the microcomputer reads the data of a
number of sound channel of a sound to be reproduced that
corresponds to the judged program type from the aforementioned
memory. Using this data of the number of sound channel of the sound
to be reproduced, the program sound number of sound channel control
circuit controls the sound signal source 30102 and controls the
number of sound channel of the sound to be reproduced. Such
configuration can reproduce a sound in appropriate number of sound
channel in accordance with a program type. Regarding the number of
reproduced sound channel control that uses the aforementioned
table, the user ought to be able to select permission/prohibition.
At that time, desirably, using an OSD circuit, a message regarding
the selection ought to be displayed on a display and processed
interactively with the user.
[0081] According to the present invention, a multiple-channel sound
signal can suitably be reproduced in accordance with a connected
state of a speaker. Further, besides the speaker connected to a
switcher and such, the speaker of a display device can be used
jointly and a higher sound effect can be obtained. Further, because
the connected state of the speakers are displayed on the display
device, an user would easily and accurately connects the
speakers.
* * * * *