Apparatus for controlling an operational panel

An apparatus for controlling an operational panel on which keyboards or change over switches are randomly arranged. Wherein the electrical circuit constitution is simple and each switch can be freely selected corresponding to whether a buzzer should be sounded or not when operating the switches. The constitution of the apparatus for controlling an operational panel includes a switch matrix (21) including n number of rows of data lines (231-23n), and m number of columns of common lines (241-24m). These data lines (231-23N) and common lines (241-24m) intersect each other. At each intersection, switches (S11-Snm) are respectively provided. Data lines (231-23n) and the common lines are connected to the receiving circuit (8), and a driving circuit (9) . Switch discriminating elements (251-25m) are connected to the receiving circuit (8) via switch discriminating data lines (26) on each of the common lines (241-24m).

TECHNICAL FIELD 
The present invention relates to an apparatus for controlling an 
operational panel on which keyboards or change over switches are arranged, 
and relates more particularly to an apparatus for controlling an 
operational panel that has a signaling function that indicates switching 
operations by a buzzer. 
BACKGROUND ART 
Recently, an apparatus for controlling an operational panel on which 
keyboards, rotary switches or other switches are arranged, is utilized for 
machine tools, etc., and has a signaling function using a buzzer when 
switching so as to provide an operator with audible feedback. This 
function is quite useful when operating switches having very little 
tactile feedback such as flat key switches. However, it can be irritating 
when operating switches that clearly provide sufficient tactile feedback, 
such as rotary switches, change over switches, etc. Therefore, in the 
prior art, it is previously determined whether the buzzer should be 
sounded for each switch or not. 
In general, a matrix circuit is used for discriminating the ON/OFF state of 
each switch on an operational panel. The matrix circuit is arranged such 
that a switch is provided for each intersection of the matrix, and the 
ON/OFF state of each switch is discriminated by driving signals sent 
through each of the common lines. 
The discrimination of whether the buzzer should be sounded or not when a 
switch is the ON state, is accomplished by providing 2 groups of common 
lines. Namely, intersections of the matrix for sounding the buzzer are 
located in a group No. 1 of common lines, while intersections of the 
matrix for not sounding the buzzer are located in a group No. 2 of common 
lines. 
Thereby the apparatus for controlling an operational panel is controlled so 
as to sound the buzzer if any of the intersections are in the ON state 
when the No. 1 group of common lines is driven, and the apparatus is 
controlled so as not to sound the buzzer if any of the intersections are 
in the ON state when the No. 2 group of common lines is driven. 
However in the prior art, there is a problem that the operational panel 
cannot be freely manufactured because the number of switches that sound 
the buzzer and the number of switches that do not sound the buzzer, have 
to be determined during the switch layout design stage of the operational 
panel. 
DISCLOSURE OF THE INVENTION 
Accordingly, it is an object of the present invention to provide an 
apparatus for controlling an operational panel comprised of a simple 
electric circuit, in the light of the above mentioned problem. A further 
object of the present invention is to provide an operational panel in 
which the switch layout on the operational panel, can be more freely 
determined. 
According to the present invention, to solve the above described problems, 
an apparatus for controlling an operational panel on which keyboards or 
change over switches are arranged, is characterized in that it comprises, 
switches arranged at each intersection of a switch matrix, a driving 
circuit for transferring drive signals to common lines of the switch 
matrix, a receiving circuit for receiving switch input signals via data 
lines of the switch matrix, switch discriminating elements for 
transferring switch discriminating signals to the receiving circuit via 
switch discriminating data lines, the signals indicating whether the 
switches should sound a buzzer or not when receiving the driving signals 
arranged on each of the common lines, an ON/OFF state discriminating means 
for discriminating the ON/OFF state of the switches after reading the 
states of the driving signals and the switch input signals, a buzzer 
driving discriminating means for discriminating whether the buzzer should 
be sounded or not by reading the switch discriminating signals via the 
switch discriminating elements when any of the switches are determined to 
be in an ON state by the ON/OFF state discriminating means, a buzzer 
driving means for sounding the buzzer when the buzzer driving 
discriminating means determines that the buzzer should be sounded. 
Each of the switch discriminating signal for discriminating whether to 
sound the buzzer or not, and which come from switch discriminating 
elements connected to the common lines transferring the driving signal 
from the driving circuit, is sent to the receiving circuit via switch 
discriminating data lines. 
If the ON/OFF state discriminating means determines that any of switches 
are in the ON state, then the buzzer driving discriminating means 
determines whether to sound the buzzer or not by reading the switch 
discriminating signal from the switch discriminating element, and the 
buzzer driving discriminating means drives the buzzer to be sounded when 
it determines to sound the buzzer. 
Therefore it is not necessary to provide the driving circuit for 
discriminating whether to sound the buzzer or not, and as a result the 
electrical circuit becomes simplified. 
Furthermore, switches can be more freely selected because the number of 
combinations of switches for which the buzzer is to be sounded or not, can 
be determined when manufacturing the operational panel.

BEST MODE FOR CARRYING OUT THE INVENTION 
An embodiment of the present invention will be explained hereinafter, 
referring to the attached drawings. 
FIG. 1 is a block diagram showing a structure of an apparatus for 
controlling an operational panel in an embodiment of the present 
invention. The apparatus for controlling an operational panel can be 
applied to a machine tool controlled by a computerized numerical 
controller (CNC). The apparatus for controlling an operational panel 
constitutes a main control unit 1 and an operational panel 2. The main 
control unit 1 mainly consists of a processor 3. The processor 3 is 
connected to an interface (INT) 5, a ROM 6 and a RAM 7 via a bus 4. The 
INT 5 receives signals from the CNC or outputs signals to the CNC. The ROM 
6 is a memory for storing a system program for controlling signals that 
are transferred through a switch matrix 21 and a LED matrix 22 in the 
operational panel 2. The RAM 7 is a memory for temporarily storing data 
during the system program execution. 
The main control unit 1 is electrically connected to the operational panel 
2. The switch matrix 21 and the LED matrix 22 are provided in the 
operational panel 2. The switch matrix 21 is connected to a receiving 
circuit (RV) 8 and a driving circuit (DV) 9 in the control unit 1. On the 
other hand, the LED matrix 22 is connected to a receiving circuit (RV) 10 
and a driving circuit (DV) 11 in the main control unit 1. In the FIG. 1, 
lines connected between the main control unit 1 and the operational panel 
2 are simply shown only as single lines, but a number of lines 
corresponding to the actual number of each matrix points are connected 
therebetween. 
A buzzer 12 is connected to the bus 4 via the buzzer driving circuit 13. 
The buzzer 12 sounds at the time when a command signal is supplied by the 
processor 3 by means of a system hereinafter explained. Next, the 
structure of the switch matrix 21 will be explained. 
FIG. 2 is a circuit drawing briefly showing the structure of a switch 
matrix circuit. The switch matrix 21 includes n rows of data lines 
231-23n, m columns of common lines 241-24m, each of the data lines 231-23n 
intersecting each of the common lines 241-24m, and switches S11 to Snm 
provided at each of the respective intersections. The data lines 231-23n 
are connected to the receiving circuit 8 and the common lines 241-24m are 
connected to the driving circuit 9. 
FIG. 3 is a drawing showing the structure of a switch S11. The switch S11 
constitutes a diode S11a for blocking reverse current, and an intersection 
switch S11b directly coupled to a flat key switch, a rotary switch or 
other type of switch on the operational panel which are not shown in the 
drawing. When the intersection switch S11b is closed while the driving 
signal DS is transferred to the common line 241 from the driving circuit 
9, the driving signal DS is being transferred to the data line 231 via the 
diode S11a. This driving signal DS is transferred to the receiving circuit 
8 as a high level switch input signal NS. 
The switches from S12 to Snm have the same constitution as the switch S11, 
so the explanation is omitted. 
Referring back to FIG. 2, switch discriminating elements 251-25m are 
provided in the common lines 241-24m. The switch discriminating elements 
251-25m are connected to a switch discriminating data line 26 which is 
connected to the receiving circuit 8. From the switch discriminating 
elements 251-25m, the switch discriminating signals HS which indicate 
whether switches arranged on each of the common lines are to sound the 
buzzer 12 or not, are output. The switch discriminating signals HS are 
high level when the buzzer 12 should be sounded, and low level when the 
buzzer 12 should not be sounded. 
FIG. 6 is a circuit drawing showing a brief structure of a switch matrix 
circuit 21' according to a prior art. The points that are different from 
FIG. 2 are that there are no switch discriminating elements 251-25m, so 
that the switch discriminating signals HS are not output to the main 
control unit 1. Therefore the operations such as dividing the common lines 
into 2 groups, providing driving circuits corresponding to each of the 
common lines, and assigning 2 groups, for example, one group for sounding 
the buzzer, the other group for not sounding the buzzer, are necessary. 
In the present embodiment, among the switch discriminating elements 251-25m 
shown in FIG. 2, the switch discriminating element 251 is predetermined as 
an output element of a high level signal, while the switch discriminating 
element 25m is predetermined as an output element of a low level signal. 
Namely the switches S11 to Sn1 on the same common line 241 as the common 
line of the switch discriminating element 251 are assigned as flat key 
switches having less tactile or audible feedback and requiring sounding by 
the buzzer 12. On the other hand, the switches S1m to Snm on the same 
common line 24m as the common line of the switch discriminating element 
25m are assigned as rotary switches or change over switches having 
adequate tactile or audible feedback and not requiring sounding by the 
buzzer 12. 
FIG. 4 is a drawing showing an example of a structure of a switch 
discriminating element 251, and a circuit for outputting the switch 
discriminating signals HS as a high level signal to the receiving circuit 
8. As shown in FIG. 4, the common line 241 is connected to the switch 
discriminating data line 26 via the diode 251a. Accordingly when a driving 
signal DS is sent to the common line 241, the driving signal DS is also 
sent to the switch discriminating line 26 via the diode 251a, and to the 
receiving circuit 8 as a high level switch discriminating signal HS. 
FIG. 5 is a drawing showing another example of a structure of a switch 
discriminating element 25m, and a circuit for outputting the switch 
discriminating signal HS as a low level signal to the receiving circuit 8. 
In this case, the anode terminal of the diode 25ma is open as shown in 
FIG. 5. The anode terminals can be left open when manufacturing the 
operational panel 2, or there could simply be nothing provided between the 
common line 24m and the switch discriminating data line 26. In this way, 
the switch discriminating signal HS is transferred to the receiving 
circuit 8 as a low level signal. 
Again referring to FIG. 2, if the driving signal DS is transferred to the 
common line 241, the switch discriminating element 251 transfers the high 
level switch discriminating signal HS to the receiving circuit 8. In this 
case, if any of the switches S11-Sn1 are on, a high level switch input 
signal NS is transferred to the receiving circuit 8. The receiving circuit 
8 transfers the signals of the switch discriminating signal HS and the 
switch input signal NS to the processor 3. The processor 3 determines 
whether the buzzer 12 should be sounded after reading the states of the 
switch discriminating signal HS, the switch input signal NS and the 
driving signal DS. The processor 3 then transfers the command signal to 
sound the buzzer 12 to the driving circuit 13, and the buzzer driving 
circuit 13 sounds by the buzzer 12. 
On the other hand, if the driving signal DS is transferred to the common 
line 24m, the switch discriminating element 25m transfers the low level 
switch discriminating signal HS to the receiving circuit 8. In this case, 
even if any of the switches S1m-Snm are on, the processor 3 judges that it 
is not necessary to sound the buzzer 12, so the command signal to sound 
the buzzer 12 is not transferred to the buzzer driving circuit 13. 
In this way, by providing the switch discriminating elements 251-25m on the 
common lines 241-24m, it is possible to preset the buzzer 12 to sound or 
not corresponding to the group of switches on each of the common lines. 
Accordingly, the constitution of the circuit of the main control unit 1 is 
simplified. 
Since it is possible to preset the number of combinations of the switches 
that sound or not when manufacturing the operational panel 2, switch 
arrangement on the operational panel can be more freely carried out. 
As heretofore explained, according to the present invention, the 
constitution of the circuit becomes simple because the apparatus for 
controlling an operational panel is constituted such that switch 
discriminating elements are provided on the common lines, and because the 
driving circuit is no longer required for discriminating whether to sound 
the buzzer or not. 
Since it is possible to preset the number of combinations of switches that 
sound or not when manufacturing the operational panel corresponding to the 
group of switches on each of the common lines, the switch arrangement on 
the operational panel can be more freely carried out.