Karaoke system and method of managing playing time of karaoke songs

A karaoke system includes: reproduction unit for reproducing a MIDI sound source control information for karaoke song from a karaoke data recording medium, the MIDI sound source control information including playing time data of the karaoke songs; operation unit for inputting request of at least one desired karaoke song and karaoke playing time; calculation unit for obtaining playing time data of the requested karaoke songs and for calculating total playing time required for playing all of the requested karaoke songs; determination unit for comparing the total playing time with remaining playing time calculated on the basis of the karaoke playing time and for determining whether all of the requested songs can be played within the remaining playing time or not; and display unit for displaying a notice related to the result of the determination of the determination unit.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to so-called karaoke system, and more particularly 
to karaoke system capable of managing playing time of karaoke songs 
utilizing data recorded according to MIDI (Musical Instrument Digital 
Interface) standard. 
2. Description of the Prior Art 
Conventionally, there are known karaoke systems constructed as illustrated 
in FIGS. 1 and 2. FIG. 1 illustrates construction of system called "LVD 
karaoke system". This LVD karaoke system K.sub.1 includes an LVD 
auto-changer PL.sub.1, a commander CM.sub.1, an operation unit CB.sub.1, 
an amplifier AM.sub.1, speakers SP.sub.1 and SP.sub.2, an image display 
device GD.sub.1 and a microphone MC.sub.1. The LVD auto-changer PL.sub.1 
reproduces information from a plurality of laser video disks D.sub.1, 
serving as karaoke information recording media, housed therein. The 
commander CM.sub.1 controls the LVD auto-changer PL.sub.1 to select a 
laser video disk D.sub.1 in the LVD auto-changer PL.sub.1 in response to 
request of songs input via the operation unit CB.sub.1. The image display 
unit GD.sub.1 displays image of reproduced image signal. The microphone 
MC.sub.1 converts singing voice into an audio signal and outputs it to the 
amplifier AM.sub.1. The amplifier AM.sub.1 mixes audio signal, serving as 
karaoke signal, from the LVD auto-changer PL.sub.1 with the audio signal 
of singing voice supplied from the microphone MC.sub.1, and outputs the 
mixed audio signal to the speakers SP.sub.1 and SP.sub.2. The speakers 
SP.sub.1 and SP.sub.2 output the mixed audio signal as acoustic sound. The 
commander CM.sub.1 may includes the operation unit CB.sub.1 in it. 
FIG. 2 illustrates construction of system called "CD karaoke system". This 
CD karaoke system K.sub.2 includes a CD auto-changer PL.sub.2, a commander 
CM.sub.2, an operation unit CB.sub.2, an amplifier AM.sub.2, speakers 
SP.sub.3 and SP.sub.4, a graphic decoder DE, an image display device 
GD.sub.2 and a microphone MC.sub.2. The CD auto-changer PL.sub.2 
reproduces information from a plurality of compact disks D.sub.2, serving 
as karaoke information recording media, housed therein. The commander 
CM.sub.2 controls the CD auto-changer PL.sub.2 to select a compact disk 
D.sub.2 in the CD auto-changer PL.sub.2 in response to a request of songs 
input via the operation unit CB.sub.2. The graphic decoder DE converts 
graphic data obtained from subcode data in the compact disk D.sub.2 into 
image signal, and the image display unit GD.sub.2 displays image of the 
image signal. The microphone MC.sub.2 converts singing voice into an audio 
signal and outputs it to the amplifier AM.sub.2. The amplifier AM.sub.2 
mixes audio signal, serving as karaoke signal, from the CD auto-changer 
PL.sub.2 with the audio signal of singing voice supplied from the 
microphone MC.sub.2, and outputs the mixed audio signal to the speakers 
SP.sub.3 and SP.sub.4. The speakers SP.sub.3 and SP.sub.4 output the mixed 
audio signal as acoustic sound. The commander CM.sub.2 may includes the 
operation unit CB.sub.2 and the graphic decoder DE in it. Using the 
systems described above, user can sing a song with accompaniment of 
karaoke music and enjoy images displayed simultaneously. The 
above-described karaoke system obtains playing time data of songs from 
data recorded in laser video disk D.sub.1 or compact disk D.sub.2, and 
simply displays playing time of each songs and total playing time. 
Recently there is a business known as "Karaoke Box" or "Karaoke Room". In 
such a business, user rents a room in which karaoke system is installed, 
enjoys singing karaoke songs, and pays for use of the room by the hour. 
User decides playing time of karaoke system (i.e., how long user enjoys 
karaoke in the room) in advance and clerks of the karaoke room notifies 
ending of the time to the user. However, in use of the above-described 
karaoke system, user sometimes makes reservation of karaoke songs without 
considering how long the playing time remains. Therefore, user is 
difficult to know how many songs he can sing within the remaining playing 
time. Sometimes, all reserved songs cannot played within the remaining 
playing time and user leaves the karaoke room with some reserved songs 
remained unsung. This is not preferable in view of management of karaoke 
box and service to users. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a karaoke system with 
which user can comfortably enjoy karaoke play until the end of the playing 
time in karaoke box. 
According to one aspect of the present invention, there is provided a 
karaoke system including: reproduction unit for reproducing a MIDI sound 
source control information for karaoke song from a karaoke data recording 
medium, the MIDI sound source control information including playing time 
data of the karaoke songs; operation unit for inputting request of at 
least one desired karaoke song and karaoke playing time; calculation unit 
for obtaining playing time data of the requested karaoke songs and for 
calculating total playing time required for playing all of the requested 
karaoke songs; determination unit for comparing the total playing time 
with remaining playing time calculated on the basis of the karaoke playing 
time and for determining whether all of the requested songs can be played 
within the remaining playing time or not; and display unit for displaying 
a notice related to the result of the determination of the determination 
unit. 
According to another aspect of the present invention, there is provided a 
method of managing playing time of karaoke songs including the steps of: 
inputting karaoke playing time in which karaoke system is played; 
inputting at least one request of desired karaoke song; calculating 
remaining playing time from present time and the karaoke playing time; 
reproducing playing time data for the requested karaoke songs from a 
karaoke data recording medium and calculating total playing time of all of 
the requested karaoke songs; comparing the remaining playing time with the 
total playing time to determine whether all of the requested karaoke songs 
can be played within the remaining playing time or not; and displaying a 
notice related to the result of the determination to notify it to the user 
.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Prior to description of a preferred embodiment of the present invention, 
details of MIDI standard, MIDI sound source and karaoke information 
recording medium according to MIDI standard will be described with 
reference to FIGS. 3A-3D and 4. 
MIDI standard and MIDI sound source: 
MIDI (Musical Instrument Digital Interface) is a standard established for 
exchanging music play information between musical instruments such as 
synthesizer or electronic piano connected with each other. Electronic 
instruments incorporating hardware according to MIDI standard and having 
functions of transmitting and receiving MIDI signal, serving as musical 
instruments control signal for defining various musical information 
according to MIDI standard, are generally called as "MIDI equipments". 
On disks such as Compact Disk (CD), Compact Disk Video (CD-V) or laser 
Video Disk (LVD) including digital audio signal of CD-format and Digital 
Audio Tape (DAT), subcode is recorded in addition to main data. Subcode is 
comprised of 8 bits data of P, Q, R, S, T, U, V and W channels, and P and 
Q channels are used for control of disk player and display. R-W channels 
are empty (blank) channels called as "user's bit". Various applications of 
the user's bit to graphic, audio or visual fields have been discussed, and 
a standard for graphic format have been already proposed. In addition, it 
is possible to record MIDI format signal in user's bit, and a standard 
thereof has been proposed. According to this application, it is possible 
to supply audio/video signal reproduced by disk player to AV system so 
that user can view a program recorded on a disk player. Further, it is 
also possible to supply play program recorded on disk to MIDI equipments. 
In this view, it has been proposed many applications of such recording 
media to AV system with MIDI equipments which gives user feeling of 
concert hall presence or studio presence, or applications to production of 
educational software. 
MIDI equipment plays music according to instrument play program of MIDI 
signal which is obtained by converting MIDI format signal obtained from 
disk player into serial signal. MIDI signal is serial data of transfer 
rate 31.25 [Kbaud (=1000 bps)]. One byte data of MIDI signal consists of 
10 bits data including 8 bits for data, 1 bit for start bit and 1 bit for 
stop bit. Status byte indicating kinds of transferred data and MIDI 
channels, and one or more data bytes introduced by the status are used in 
combination to form a message serving as musical information. Accordingly, 
one message generally consists of 1 to 3 bytes, and transfer time of one 
message ranges from 320 to 960 [.mu.sec]. These successive messages 
constitute instrument play program. 
MIDI karaoke information recording medium: 
Next, an example of information recording medium according to MIDI standard 
will be described with reference to FIGS. 3A-3D and 4. FIGS. 3A-3D 
illustrate data format of MIDI karaoke file stored in Optical Memory Disk 
(OMD) serving as karaoke information recording medium. OMD is recordable 
optical disk used as memory. As illustrated, MIDI karaoke file format 
includes note file NF which is area for storing MIDI sound source control 
information, expansion file EF which is area for storing equipment control 
information, lyrics file LF which is area for storing lyrics 
(words-of-song) information and PCM file PF which is area for recording 
supplemental accompaniment information. The lyrics file LF includes quick 
reference data serving as retrieval information. The lyrics file LF, the 
PCM file PF and the expansion file EF constitute karaoke-related 
information recording area. The note file NF stores actual play data, and 
includes data areas NF.sub.1 -NF.sub.15. The lyrics file LF stores data of 
lyrics telop displayed on a monitor TV, and includes data areas LF.sub.1 
-LF.sub.9. The data areas LF.sub.1 -LF.sub.3 also includes quick reference 
data. 
FIG. 4 illustrates an example of file-header LF.sub.1 in the lyrics file 
LF. In this area, total playing time data of standard playing mode is 
recorded in the areas of (W+12)th-(W+13)th bytes, and total playing time 
of short playing mode (2 chorus playing)is recorded in the areas of 
(W+15)th-(W+16)th bytes. Playing time of omnibus playing mode is recorded 
in the areas of (W+18)th-(W+19)th bytes. 
Karaoke system: 
Next, MIDI karaoke system according to the present invention will be 
described below with reference to the accompanying drawings. As 
illustrated in FIG. 5, MIDI karaoke system 110A roughly includes a MIDI 
control device 1, a sound output system 2, an image display system 3, a 
microphone 4, a lighting system 10 and a quick reference system 14. 
Additionally, a data transmission system 11 and a data transmission system 
12 connected to the data transmission system 11 via telephone line 13 may 
be provided. 
The MIDI control device 1 includes an Optical Memory Disk Drive (OMDD) 5 
for recording and/or reproducing karaoke information, a MIDI sound source 
module 6, a board computer 8, an operation unit 15, a storage unit 21 
which may be a hard disk for storing control program of the board computer 
8, a D/A converter 22, a key-controller 23, a mixer 24, a superimposition 
circuit 25, a video processing circuit 26, a power supply 27, a power 
supply switch 28, interfaces 29-35 and a volume control block 36. The 
sound output system 2 includes an amplifier 41, a sound effector 42, 
speakers 43 and 44. The image display system 3 includes a LVD player 7, an 
image effector 51, a video camera 52, a user display 53, a reservation 
display 54 and a singer display 57. The quick reference system 14 includes 
a user terminal 9, a MIDI sound source module 55 and a headphone 56. The 
lighting system 10 includes a lighting controller 61, a driver 62 and a 
lighting device 63. The data transmission system 11 includes a 
microcomputer 71, a storage unit 72 and a modem 73. The data transmission 
system 12 includes a central computer 74, a modem 75 and a storage unit 
76. 
Next, time management operation of MIDI karaoke system according to the 
present invention will be described with reference to FIG. 6. Quick 
reference data IF, which is a part of MIDI karaoke data, is supplied to 
RAM 8M in the board computer 8 at starting time of the system. Then, user 
retrieves quick reference data IF and requests desired songs using the 
operation unit 15 (Step 100). It is noted that ending time of using 
karaoke room has been input to the board computer 8 in advance. Then, in 
response to the request, the board computer 8 reads out data of the 
requested songs (i.e., note file NF, lyrics file LF and PCM file PF) from 
the OMDD 5, and stores it in the RAM 8M. Subsequently, the board computer 
8 reads out playing time data of standard playing mode for the requested 
songs from the portions of (W+12)th-(W+13)th bytes of the file header 
portion LF.sub.1 in lyrics file LF stored in the RAM 8M (Step 101), and 
calculates total playing time required for playing all requested songs 
(Step 102). Then, the board computer 8 compares remaining playing time 
(time length from the present time until the ending time of using the 
karaoke box) with the calculated total playing time (Step 103), and 
determines whether the remaining time is shorter than the total playing 
time or not (Step 104). If the remaining time is longer than the total 
playing time (Step 104:NO), user actually makes reservation of the 
requested songs using the operation unit 15 (Step 115) and then the 
process ends. On the other hand, if the remaining playing time is shorter 
than the total playing time (Step 104:YES), the board computer 8 reads out 
playing time data of short playing mode for the requested songs from the 
portions of (W+15)th-(W+16)th bytes of the file header portion LF.sub.1 in 
lyrics file LF stored in the RAM 8M (Step 105). Then, the board computer 
calculates total playing time of the requested songs for a case where last 
song of the requested songs is played by the short playing mode and the 
other requested songs are played by the standard playing mode (Step 106). 
Then, the board computer 8 compares the remaining playing time with the 
total playing time newly calculated (Step 107), and determines whether the 
remaining time is shorter than the total playing time or not (Step 108). 
If the remaining time is longer than the total playing time (Step 108:NO), 
user actually makes reservation of the requested songs using the operation 
unit 15 (Step 115) and then the process ends. 
On the other hand, if the remaining time is still shorter than the total 
playing time (Step 108:YES), the board computer determines whether there 
exists a song previous (requested prior) to the last song (Step 109). If 
there exists no requested song previous to the last song (Step 109:NO), 
the display 54 displays a notice that "REMAINING TIME IS NOT ENOUGH" (Step 
110) and the process ends. If there exist requested song previous to the 
last song (Step 109:YES), the board computer 8 newly calculates total 
playing time for a case where the song requested just before the last song 
is also played by the short playing mode (Step 111). Subsequently, the 
board computer 8 compares the remaining time with the total playing time 
newly calculated and determines whether the remaining time is longer than 
the total playing time or not (Step 112). If the remaining time is still 
shorter (Step 112:NO), Steps 109, 111 and 112 are repeated. Namely, the 
board computer 8 calculates total playing time for a case where last three 
requested songs are played by the short playing mode and the other 
requested songs are played by the standard playing mode, and compares the 
total playing time newly calculated with the remaining time. On the other 
hand, if the remaining time is longer than the total playing time (Step 
112:YES), the display 54 displays a notice that "ALL SONGS CAN BE RESERVED 
IF nTH THRU LAST SONGS ARE PLAYED BY SHORT PLAYING MODE" (Step 113). Then, 
the board computer 8 asks user whether he wishes to reserve the requested 
songs in that manner or not (Step 114). If user wishes to reserve the 
songs (Step 114:YES), he instructs reservation of the requested songs in 
that manner via the operation unit 15 (Step 115), and the process ends. On 
the other hand, if user does not wish to reserve the songs in that manner 
(Step 114:NO), the process ends without making reservation. 
As described above, according to the present invention, the system extracts 
playing time of requested songs, calculates total playing time of the 
songs and compares it with the remaining time to determine whether all 
requested songs can be played within the remaining time or not. Therefore, 
karaoke play of all requested songs are completed before the ending time 
of using the karaoke room. Clerks of the karaoke room does not have to 
notify ending time of the karaoke room to user. Further, since playing 
time data of short playing mode is also prepared and recorded, user can 
reserve and sing many karaoke songs utilizing short play mode. 
The invention may be embodied on other specific forms without departing 
from the spirit or essential characteristics thereof. The present 
embodiments are therefore to be considered in all respects as illustrative 
and not restrictive, the scope of the invention being indicated by the 
appended claims rather than by the foregoing description and all changes 
which come within the meaning an range of equivalency of the claims are 
therefore intended to be embraced therein.