Educational apparatus with automatic terminal identification

An educational apparatus, of the language laboratory type, includes a master control unit operated by the teacher and which is associated with a plurality of student terminal control units so that the teacher can monitor the student's responses and immediately answer any questions by the students. Each terminal control unit includes any information signal input for receiving an information signal, such as a question from a student, an information signal transmitting circuit adapted to receive the information signal from the respective input and to transmit the same to a monitoring device, such as a headphone set, at the master control unit and a call signal input for supplying a call signal, as when a student has a question, to the respective transmitting circuit and also to a respective indicating device, such as a light emitting diode, at the master control unit, for indicating that a student has a question. The master control unit includes an incoming call switch for making operative the respective transmitting circuit when a call signal is supplied thereto, whereby to pass the respective information signal through the operated transmitting circuit to the monitoring device of the master control unit. The educational apparatus also includes a mobile control unit for controlling the operation of the master control unit, in the same manner as described above, while the teacher walks among and observes the students.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an educational apparatus and, more particularly, 
is directed to an educational apparatus of the language laboratory type 
having a master console which is associated with a plurality of student 
terminals. 
2. Description of the Prior Art 
With known educational apparatus of the above type, a teacher must spend 
much time during a lesson in the operation of the apparatus, making it 
difficult to provide any effective communication between the teacher and 
the students. This is especially the case in known apparatus of the 
language laboratory type which requires continual observation of a master 
control console by the teacher during the entire lesson. This is due to 
the fact that, during the lesson, the teacher monitors the exercises of 
the students, and answers questions from and advises the students. 
In known language laboratory apparatus, a sequential scanning means is 
typically provided which is capable of automatically carrying out 
sequential monitoring of the students, and which scans all student 
terminals sequentially in the forward or reverse directions. Such systems 
usually also enable manual scanning of particular terminals through an 
added control circuit. 
Although the aforesaid educational apparatus enables automatic sequential 
monitoring, there are certain disadvantages associated therewith. For 
example, the master console typically includes an indication device, such 
as a lamp, which is adapted to blink on and off in response to the 
depression of a control button at any one of the student terminals for 
informing the teacher that a student has a question about the lesson. 
However, since only one lamp is typically provided, the teacher does not 
known which student is calling and consequently, must spend much time and 
effort determining this before responding to the call. Alternatively, some 
master consoles are provided with a plurality of lamps, each associated 
with a respective student terminal. In this case, however, the teacher 
must continually monitor the lamps, making it difficult to provide any 
effective supervision over the lesson. 
Further, it is generally desirable for the teacher to observe the students 
during the lesson, while also monitoring their responses. Since the 
teacher cannot watch the call lamps while walking among the students, it 
is necessary for an operator to remain at the master console to call the 
teacher back when there is a call from a student. In addition, a 
monitoring jack may be provided at each student terminal so that the 
teacher can plug in a headphone set thereat while walking among the 
students in order to monitor the responses of the students. This system, 
however, has serious drawbacks in that it is difficult to proceed with the 
lesson because the students are aware of the monitoring by the teacher. 
OBJECTS AND SUMMARY OF THE INVENTION 
Accordingly, it is an object of this invention to provide an educational 
apparatus that avoids the above-described difficulties encountered with 
known educational apparatus. 
More particularly, it is an object of this invention to provide an 
educational apparatus which informs the teacher when a student has a 
question and enables the teacher to instantly communicate with that 
student for responding to the question. 
It is another object of this invention to provide an educational apparatus 
which does not require continual monitoring of a plurality of indicating 
devices by the teacher to determine when a student has a question. 
It is still another object of this invention to provide an educational 
apparatus in which the teacher, while walking among the students, can be 
informed of a call from a student and instantly communicate with that 
student in response to the call. 
In accordance with an aspect of this invention, an educational apparatus 
includes a plurality of terminal control means each including information 
signal input means, information signal transmitting means for receiving an 
information signal from the respective input means, and call signal input 
means operative to provide a call signal by which the respective 
transmitting means is conditioned to be made operative for transmitting 
the information signal received from the respective input means. The 
educational apparatus further includes master control means including 
indicating means for indicating when a call signal is received from the 
call signal input means of any of the terminal control means, monitoring 
means for monitoring the information signal from any one of the terminal 
control means, and incoming call switch means actuable to cause operation 
of the transmitting means of the one of the terminal control means which 
has had its call signal input means operated to provide the call signal, 
whereby to pass the information signal through the operated transmitting 
means to the monitoring means. 
In a preferred embodiment, the educational apparatus also includes a mobile 
control means through which the teacher can control the operation of the 
master control means while walking among the students. 
The above, and other objects, features and advantages of the invention, 
will be apparent in the following detailed description of preferred 
embodiments which is to be read in connection with the accompanying 
drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to the drawings in detail, and initially to FIG. 1, there is 
shown therein a known educational apparatus, such as an audio language 
laboratory, in which a student listens to a phrase from a tape, for 
example, in a foreign language, and then either repeats the phrase or 
supplies an answer thereto. In order for the teacher to observe the 
progress of any student, a monitoring system is provided which 
sequentially monitors the students' responses and transmits the same to a 
master console. At this time, it should be recognized that, although the 
following discussion is primarily directed to an audio educational 
apparatus, any other sensory operation may be utilized which is capable of 
performing an educational function. 
As shown in FIG. 1, the language laboratory is comprised of a plurality of 
student terminal control units 2, for example, as indicated at 2-1-2-n, 
and a master control unit 4 connected to and adapted to control the 
operation of each terminal control unit 2. Each terminal control unit 2 
includes an amplifier 6 which receives and amplifies an audio information 
signal S from the student, and a control circuit 8 connected to amplifier 
6 and adapted to transmit the amplified information signal to master 
control unit 4. 
Master control unit 4 is operated by the teacher and includes a monitor 
console 10 adapted to receive the amplified information signals from 
selective ones of terminal control units 8 so that the teacher can observe 
the progress of each student. In this regard, master control unit 4 
includes a terminal selection circuit 12 for selecting particular terminal 
control units 2 which are to be sequentially monitored by the teacher. 
Selection circuit 12 is connected to each control circuit 8 for 
controlling the transmission therefrom of the amplified information 
signals to monitor console 10. A selection switch circuit 14 is connected 
to terminal selection circuit 12 in order to allow passage of the 
amplified information signals to monitor console 10 from only a 
preselected number of terminal control units 2. In like manner, a blocking 
switch circuit 16 is connected to terminal selection circuit 12 for 
allowing transmission of the amplified information signals to monitor 
console 10 from the remaining blocked terminal control units 2 that were 
not preselected. Also, where the terminal control units 2 are divided into 
groups, that is, for different student levels or the like, a group 
selection circuit 18 is connected to each control circuit 8 to allow 
transmission of the amplified information signals from a preselected 
group. A program selection circuit 20 is also connected to each control 
circuit 8 so that the teacher is able to monitor only those terminal 
control units 2 that are implementing the same language program. 
Master control unit 4 further includes a scanning circuit 22 for 
sequentially scanning terminal control units 8 that have been preselected 
by circuits 12, 18 and 20. Scanning circuit 22 includes a shift register 
24 connected to each control circuit 8, and an automatic scan switch 
circuit 26 is connected to shift register 24 through a selector circuit 28 
for actuating shift register 24 to sequentially scan, in the reverse or 
forward direction, the preselected terminal control units 2. A manual scan 
switch circuit 30 is connected directly, and through an oscillator 32, to 
selector circuit 28. Oscillator 32 normally supplies an output signal to 
selector circuit 28 when automatic scan switch circuit 26 is actuated. 
When manual scan switch circuit 30 is actuated, for example, by the 
depression of a momentary contact, push-button switch (not shown), the 
output of oscillator 32 is momentarily suspended and a sequential scanning 
signal is supplied from selector circuit 28 to shift register 24 to enable 
scanning of the terminal control unit 2 succeeding the one presently being 
scanned. If the push button is retained in a depressed condition, shift 
register 24 is caused to sequentially scan terminal control units 2 at a 
faster rate than normally occurs under the control of automatic scan 
switch circuit 26. Thus, the teacher is able to observe the progress of 
any student when desired. If a terminal control unit 2 being scanned is 
blocked, that is, not preselected, a high-speed oscillator 34 is driven by 
the output of the control circuit 8 of the scanned terminal control unit 
to supply a high-speed pulse to selector circuit 28 for bypassing, at a 
rapid rate, that terminal control unit 2. 
Although the aforesaid educational apparatus enables automatic sequential 
monitoring, there are certain disadvantages associated therewith. For 
example, master control unit 4 typically includes an indication device 
(not shown), such as a lamp, which is adapted to blink on and off in 
response to the depression of a control button at each student's terminal 
for informing the teacher that a student has a question about the lesson. 
However, since only one lamp is typically provided, the teacher does not 
known which student is calling and consequently, must spend much time and 
effort determining this before being able to respond to the call. 
Alternatively, some master control units are provided with a plurality of 
lamps, each associated with a respective student terminal. In this case, 
however, the teacher must continually monitor the lamps, making it 
difficult to provide any effective supervision over the lesson. 
Further, it is generally desirable for the teacher to observe the students 
during the lesson, while also monitoring their responses. Since the 
teacher cannot watch the call lamps while walking among the students, it 
is necessary for an operator to remain at the master control unit to call 
the teacher back when there is a call from a student. Alternatively, a 
monitoring jack may be provided at each terminal control unit so that the 
teacher can plug in a headphone set thereat while walking among the 
students in order to monitor the responses of the students. This system, 
however, has serious drawbacks in that it is difficult to proceed with the 
lesson because the students are aware of the monitoring by the teacher. 
Referring now to FIG. 2, it will be seen that, in one embodiment of an 
educational apparatus according to this invention, elements corresponding 
to those described above with reference to the known educational apparatus 
of FIG. 1 are identified by the same reference numerals with primes 
appended thereto. Thus, in the educational apparatus of FIG. 2, a master 
control unit 4' is connected to and controls the operation of a plurality 
of student terminal control units 2'-1-2'-n. 
The following discussion will be directed to the relation between master 
control unit 4' and terminal control unit 2'-1, although it is to be 
realized that the same relation exists between master control unit 4' and 
all the other terminal control units 2'-1-2'-n which are similar to each 
other. Terminal control unit 2'-1 is shown to include an information 
signal input terminal V.sub.1 which is supplied with the amplified 
information signal from an amplifier (not shown). The information signal 
may be, for example, a question by the student or merely the student's 
response to the lesson. The information signal is supplied in unit 2'-1 to 
an information signal transmitting circuit 36.sub.1, which is adapted to 
transmit the signal to monitor console 10' of master control unit 4'. 
Monitor console 10' is shown to include an amplifier 10a and an 
electro-audio transducer 10b, such as, a headphone set or the like. As 
shown, transmitting circuit 36.sub.1 may include a gate G.sub.1 which is 
connected between input terminal V.sub.1 and monitor console 10' and which 
is adapted to transmit the information signal when a logic level "1" 
signal is supplied to its control input. Gate G.sub.1 has its control 
input connected to the output of a NAND circuit 38.sub.1 of transmitting 
circuit 36.sub.1. Thus, when a logic level "1" signal is produced by NAND 
circuit 38.sub.1, that is, when a logic level "0" signal is supplied to 
any input thereof, the information signal from terminal V.sub.1 is 
transmitted to monitor console 10'. 
NAND circuit 38.sub.1 has one of its inputs connected, through an inverter 
I.sub.1, to a shift register 24' of master control unit 4'. When the 
output Y.sub.1 from shift register 24' is at logic level "1," one input to 
NAND circuit 38.sub.1 is at logic level "0" and the information signal 
from terminal V.sub.1 is transmitted to monitor console 10'. 
Master control unit 4' includes an automatic scan switch 40 and a manual 
scan switch 42 which are connected between ground and the reset and set 
terminals, respectively, of a flip-flop circuit 44. An oscillator 46 is 
connected to the output of flip-flop circuit 44 and to shift register 24' 
through an AND circuit 48. Manual scan switch 42 is also connected between 
another input of AND circuit 48 and ground. When automatic scan switch 40 
is closed, oscillator 46 produces sequential pulses which are applied to 
shift register 24' through AND circuit 48 for causing master control unit 
4' to sequentially scan terminal control units 2'. However, at this time, 
shift register 24' only produces a logic level "0" output which, when 
inverted by inverter I.sub.1, is supplied to NAND circuit 38.sub.1 as a 
logic level "1" signal. Thus, unless the other input to NAND circuit 
38.sub.1 is at logic level "0," no transmission of the amplified 
information signal from terminal V.sub.1 occurs. 
On the other hand, when manual scan switch 42 is closed, flip-flop 44 is 
set, stopping oscillator 46 from producing an output signal. The outputs 
of AND circuit 48 and shift register 24' are then at logic level "1" and a 
logic level "0" signal is supplied to an input of NAND circuit 38.sub.1. 
This means that, regardless of the signal applied to the other input of 
NAND circuit 38.sub.1, a logic level "1" signal is supplied to gate 
G.sub.1 to allow transmission of the amplified information signal from 
terminal V.sub.1 to monitor console 10'. The teacher can thus monitor any 
student's terminal in the same manner as the apparatus of FIG. 1. 
Terminal control unit 2'-1 also includes a monitor switch SW.sub.1, 
connected between ground and the other input of NAND circuit 38.sub.1, 
through a non-inverting amplifier 50.sub.1. When switch SW.sub.1 is open, 
a logic level "1" signal is supplied to NAND circuit 38.sub.1, and when 
closed, a logic level "0" signal is supplied thereto to enable 
transmission of the amplified information signal to monitor console 10'. 
This enables the teacher to listen to, for example, the entire class if 
all monitor switches SW.sub.1 -SW.sub.n are closed, although normally, 
such switches are retained in an open position. 
Terminal control unit 2'-1 is provided with a call signal input terminal 
C.sub.1 which is supplied with a call signal when a call switch (not 
shown) is closed by the student, for example, when the student has a 
question concerning the lesson. A student indicating device is connected 
between terminal C.sub.1 and ground for indicating when the respective 
call switch has been closed, and is comprised of a resistor 52.sub.1 and a 
light emitting diode (LED) 54.sub.1, although any other indicating device, 
such as an audible buzzer 53.sub.1, can be utilized. A similar indicating 
device is provided on master control unit 4'. This latter indicating 
device is connected to terminal C.sub.1 through a capacitor 55.sub.1 and a 
diode D.sub.1 and is comprised of a light emitting diode (LED) 56 and 
resistor 58 connected, in series, to the collector of a transistor 60, 
which has its emitter connected to ground and its base connected to diode 
D.sub.1 through an input resistor 62. In like manner, an audible buzzer 61 
may be provided at master control unit 4'. Thus, when the student has a 
question and closes the respective call switch, LEDs 54.sub.1 and 56 are 
activated so as to blink on and off. In this manner, the teacher is 
informed that a student has a question, although the identity of the 
student is still unknown. 
As shown in FIG. 2, information signal transmitting circuit 36.sub.1 also 
includes a transistor T.sub.1 which has its base connected to terminal 
C.sub.1 through a resistor 64.sub.1 and capacitor 55.sub.1. The collector 
of transistor T.sub.1 is connected to one input of NAND circuit 38.sub.1 
through a resistor 66.sub.1 and through amplifier 50.sub.1, and transistor 
T.sub.1 has its emitter connected to ground through an incoming call 
switch 68 at master control unit 4'. When no call signal is supplied to 
terminal C.sub.1, light emitting diodes 54.sub.1 and 56 and transistor 
T.sub.1 are in their OFF states, so that a logic level "1" signal is 
supplied to NAND circuit 38.sub.1 from transistor T.sub.1. When a call 
signal is supplied to terminal C.sub.1, diode 56 blinks on and off, 
indicating to the teacher that a student has a question. However, 
transistor T.sub.1 is still retained in its OFF state until incoming call 
switch 68 is closed by the teacher, completing the circuit for transistor 
T.sub.1. Once this switch is closed, transistor T.sub.1 turns ON and a 
logic level "0" signal is supplied to NAND circuit 38.sub.1. This permits 
transmission of the information input signal, in the form of a question 
from the student, to monitor console 10'. Thus, the teacher is then able 
to instantly determine which student is asking the question and can 
respond to it. 
Call incoming switch 68 is also connected to the set terminal of a 
flip-flop circuit 70 of master control unit 4'. A reset switch 72 is 
connected between the reset terminal of flip-flop circuit 70 and ground. 
The output of flip-flop circuit 70 is connected to the emitter terminal of 
a transistor T.sub.1 ', which has its base connected to the output of NAND 
circuit 38.sub.1 through a resistor 74.sub.1, and its collector connected 
to a break-in or interrupt terminal B.sub.1 of terminal control unit 2'-1. 
When a logic level "1" signal is supplied to transistor T.sub.1 ' from 
NAND circuit 38.sub.1, and call incoming switch 68 is closed to receive 
the question by the student, transistor T.sub.1 ' is in its ON state (with 
its emitter grounded through flip-flop 70) so as to supply an output logic 
level "0" signal to break-in terminal B.sub.1 which, for example, controls 
the output of a tape recorder 77 in respect to that student. For example, 
the output of tape recorder 77 to terminal control unit 2'-1 may be 
interrupted in response to the logic level "0" at terminal B.sub.1 so that 
the teacher and student may freely communicate with each other without any 
disturbance from the lesson tape. When the communication with the student 
is at an end, reset switch 72 is closed to reset flip-flop to its original 
state, resulting in the output of tape recorder 77 once again being 
supplied to terminal control unit 2'-1. 
Master control unit 4' also includes an interrupt switch 76 which is 
connected to ground and to the collectors of transistors T.sub.1 '-T.sub.n 
' through respective diodes D.sub.1 '-D.sub.n ' of terminal control units 
2'-1-2'-n. Thus, when desired, the teacher can interrupt the output of 
tape recorder 77 to all terminal control units 2'-1-2'-n. 
It can readily be seen from the above discussion that only one light 
emitting device 56 is required to inform the teacher that a student has a 
question, although the identity of the student is unknown at that time. 
Further, by merely closing switch 68, the teacher is immediately placed in 
communication with that student and can respond to the question without 
incurring any great effort in determining the student's identity 
beforehand. 
Referring now to FIG. 3, there is shown a second embodiment of this 
invention, in which elements corresponding to those described above with 
reference to the embodiment of FIG. 2, are identified by the same 
reference numerals and operate in the same manner. In the embodiment of 
FIG. 3, a mobile control unit 78 is adapted to communicate with, and 
control master control unit 4" while the teacher is walking among and 
observing the students. In this regard, master control unit 4" includes a 
console transmitter 80 which is adapted to receive an indicating signal 
from transistor 60 and an amplified information signal from amplifier 10a 
and transmit the same to a corresponding mobile receiver 82 of mobile 
control unit 78. Thus, when an incoming call signal is supplied to 
terminal C.sub.1, a buzzer (not shown) on mobile control unit 78 can be 
activated to inform the teacher that a student has a question. In like 
manner, mobile control unit 78 includes a mobile transmitter 84 which is 
adapted to transmit appropriate signals to a corresponding console 
receiver 86 of master control unit 4". Mobile transmitter 84 is shown to 
have switches 40, 42, 68, 72 and 76 associated therewith and which 
correspond to respective terminals 88-92 of console receiver 86. It will 
be appreciated that switches 40, 42, 68, 72 and 76 associated with mobile 
transmitter 84 operate in the same manner as the correspondingly numbered 
switches in the embodiment of FIG. 2. 
As shown on FIG. 4, the NAND circuit 38.sub.1 in the embodiment of FIG. 2 
or FIG. 3 can be replaced by an inverter circuit 39.sub.1, with the 
signals from inverter I.sub.1, transistor T.sub.1, and switch SW.sub.1 all 
being applied to one input of inverter 39.sub.1. Thus, when an output 
signal from any one of these elements I.sub.1, T.sub.1, and SW.sub.1 is at 
a logic level "0," gate G.sub.1 would have supplied thereto the necessary 
logic level "1" signal for transmission of the amplified information 
signal. 
Having described specific preferred embodiments of the invention with 
reference to the accompanying drawings, it is to be understood that the 
invention is not limited to those precise embodiments, and that various 
changes and modifications in addition to those specified above may be 
effected therein by one skilled in the art without departing from the 
scope or the spirit of the invention as defined in the appended claims.