JPS6235131B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compact keyboard, and more particularly to a micro-compact flat keyboard.

In general, keyboards can be roughly divided into two types depending on the key structure: button-type keyboards, in which each key has a button, and keyboard-type keyboards, in which each key has a button, and keyboards do not have buttons, but key identification symbols are displayed on a flat surface to indicate the key position. There is a flat type, but in both types, the spacing between each key is ergonomically designed to prevent so-called double touch, which occurs when pressing two or more keys at the same time when pressing a key with a finger. It has been expanded to a certain extent. Therefore, it has been impossible to reduce the size of a keyboard with keys arranged at such intervals below a certain level. As a solution to this problem with small keyboards, keyboards with small keys have been made in which the keys are pressed with the tip of a pencil, but such keyboards have the disadvantage that they are extremely difficult to use. Ta.

An object of the present invention is to solve the above-mentioned conventional problems and eliminate their drawbacks, and to press each key directly with a human finger without causing double-touch failure as in the conventional method. It is an object of the present invention to provide a compact keyboard using a completely new method in which the distance between them can be made extremely narrow.

The invention will be explained in detail below by way of example embodiments with reference to the drawings.

FIGS. 1A to 1E each illustrate each component of an example of a small flat keyboard according to the present invention. The front plate MP shown in FIG. 1A is a board in which identification symbols KPR for each key are closely arranged in a matrix and printed on a flexible thin plate made of an insulating material. It shows the position of the keys, and should be slightly smaller than the area that your fingertips touch. The Y-pattern plate YP shown in FIG. It is printed on the bottom surface of a flexible thin plate of insulating material, and is divided into individual wires and connected to output terminals Y ₀ , Y ₁ , Y ₂ and Y ₃ in common. At the end where the resistor array RAY is inserted, as shown in an enlarged view in FIG. 1C, resistive elements each having the same resistance value R ohm are connected in series to each conductor line. The pressure-sensitive conductive rubber sheet GP shown in FIG. 1D is designed so that when a pressing force is applied, only the portion to which the pressure is applied exhibits conductivity in the thickness direction. The X-pattern plate XP shown in FIG. 1E extends in the direction of each row in which each key is arranged in a matrix, that is, in the direction orthogonal to the conductor strip pattern YPTN on the Y-pattern board YP shown in FIG. 1B. The existing comb-shaped parallel conductor wire pattern XPTN, in which a resistor array RAX is inserted at one end, is divided into a plurality of identical wires corresponding to each column, and each has a common output terminal X ₀ , _X1 ,
It is connected to X ₂ , X _{3 and} The same shall apply.

The thin plates of each component shown in Fig. 1 A, B, D, and E are assembled in the order MP→YP→GP→XP shown in Fig. 2.
They are overlapped and brought into close contact to form a keyboard KB as shown in Fig. 3.

The keyboard KB configured as described above is
As shown in the figure, when pressed with the fingertip F, only the part of the pressure-sensitive conductive rubber sheet GP shown in black in the figure where pressure is applied becomes conductive, and the conductor on the bottom surface of the Y-pattern plate YP in contact with that part becomes conductive. Each conductor filament of the filament pattern YPTN and each conductor filament of the conductor filament pattern XPTN on the top surface of the X pattern XP are
They will be electrically connected to each other at each intersection.

FIG. 5 shows an example of the configuration of the keyboard drive circuit of the present invention for determining the position of a pressed key by the conduction between the crossed conductor lines as described above. In the drive circuit having the configuration shown in FIG.
Signal applied to the base of TRY via resistor R2
YON is a control signal for applying a voltage to the conductor strip pattern YPTN in the row direction, and when this control signal YON becomes the ground potential, the applied voltage +V is divided by resistors R1 and R2, and the transistor
Since the base potential approaches the collector potential, the transistor TRY becomes conductive and is connected to each output terminal Y0 to Y3 of the row direction conductor strip pattern YPTN on the keyboard KB via each diode DY0 to DY3. A voltage +V is applied. On the other hand, the signal XON applied to the base of the transistor TRX via the resistor R4 is a control signal for applying a voltage to the conductor strip pattern XPTN in the column direction, and when this control signal XON reaches the ground potential, the applied voltage +V is divided by resistors R3 and R4 and applied to the base of the transistor TRX, and the base potential approaches the collector potential, so the transistor TRX becomes conductive and the keyboard voltage is applied via each diode DX0 to DX4.
A voltage +V is applied to each output terminal X0 to X4 of the column direction conductor strip pattern XPTN in KB.

Therefore, each output terminal Y0~Y3 and X0~
X4 is grounded through resistors RY0 to RY3 and RX0 to RX4, which have the same resistance value R' ohms, respectively, and is connected to each input terminal Z0 to Z8 of the analog data selector DSL, respectively. Analog data selector DSL
The selected output signal selected as described later by the selection control signal CSL is output from the output terminal OUT of
XYNV is supplied to an analog-to-digital converter ADC, and a conversion output signal NV is taken out. Note that the selection control signal CSL is the analog data selector DSL.
The selection of which of the conductor wire output terminal voltages applied to each of the input terminals Z0 to Z8 is guided to the output terminal OUT is controlled as will be described later.

However, in the small keyboard of the present invention,
As mentioned above with reference to Figure 1, for example, the keys, which are slightly smaller in size than the area that the fingertips touch, are closely arranged in a matrix, so when pressing each key, the keys shown in Figure 6 are colored black. As shown, at the same time as the desired key, a portion of the adjacent key is also pressed. In this way, when the operator presses the key □5 and also presses some of the keys □2, □3, and □6 at the same time, in the present invention, the pressed several keys Among them, the key with the largest area of the blacked part, in the example of FIG. 6, the key □5, is determined to be the key desired to be pressed.

That is, for example, when a key is pressed as shown in FIG.
The conductor line pattern XPTN in the column direction means that each intersection of these conductor line patterns in the pressed part is in a conductive state via the pressure-sensitive conductive rubber sheet GP, as shown with black dots in Figure 7. becomes. That is, for example, most of the conductor wires connected to the output terminal Y1 in the row direction, a part of the conductor wires connected to the output terminal Y2, and the output terminal X2 in the column direction.
Most of the conductor wires connected to the output terminal
Each intersection with a portion of the conductor wire connected to 3 becomes electrically conductive.

In such a conductive state, in accordance with the timing chart for determining whether a pressed key is pressed as shown in FIG. When the direction control signal XON is set to a high level potential, that is, "1", the power supply voltage +V is applied to the row direction output terminals Y0 to Y3 of the keyboard KB, and the voltage +V applied to these terminals increases the resistance in the row direction. The array RAY, each intersection in the conductive state shown by the black dots in Figure 7, and the resistor array in the column direction.
RAX and output terminal X0 in the column direction.
~X4. Since the column direction output terminals X0 to X4 are grounded via the resistors RX0 to RX4, respectively, the voltage appearing at each output terminal X0 to X4 is equal to the applied voltage +V connected to the conduction intersection. Ratio of the resistance value obtained by dividing the series resistance value 2R of the row direction resistance array RAY and the column direction resistance array RAX by the number of conduction intersections belonging to each X terminal and the resistance value R' of the column direction grounding resistance RX0 to RX4. Therefore, each column direction output terminal X0 to X4 has a voltage value divided by
, a voltage value corresponding to the number of conductive intersections belonging to each output terminal appears, that is, the larger the number of conductive intersections, the closer the voltage value appears to the applied voltage +V. Since the X terminal output voltage is supplied to each input terminal Z4 to Z8 of the data selector DSL, the selection control signal CSL of the data selector DSL is applied to each X output terminal as shown in the timing chart of FIG. The analog voltage value of the output signal are compared with each other by conventional means to determine the highest X terminal output voltage. That is, among the column-direction output terminals X0 to X4, the output terminal with the largest number of connected conductive intersections, for example, the column-direction output terminal X2 in the example shown in FIG. 7, is determined.

Next, in the second half of the test cycle in the timing chart shown in FIG. 8, when the row direction control signal YON is set to a high level potential "1" and the column direction control signal XON is set to the ground potential "0", the test cycle begins. Contrary to what was mentioned above regarding the first half,
A power supply voltage +V is applied to each of the column direction output terminals X0 to X4 of the keyboard KB, and the output terminal at which the highest voltage appears among the row direction output terminals Y0 to Y3 is determined in the same manner as described above. . For example, the row direction output terminal Y1 in the example shown in FIG. 7 is determined.

As described above, based on the fact that the highest voltage has appeared at the row direction output terminal Y1 and the example direction output terminal X2, for example, the 6. It can be determined that the key □5 in the example shown in FIG. 6 has been pressed.

As is clear from the above description, in the small keyboard of the present invention, even if multiple keys are pressed at the same time, the key on which the operator's fingertip presses the widest area is determined to be the desired pressed key. Therefore, it is possible to realize a keyboard that is much smaller than the conventional keyboard, in which keys having a size smaller than the area in contact with the fingertips are closely arranged in a matrix.

[Brief explanation of the drawing]

1A to 1E are diagrams showing each component of the keyboard of the present invention, FIG. 2 is a perspective view showing how these components are superimposed, and FIG. 3 is a diagram showing the appearance after completion. FIG. 4 is a sectional view showing the manner in which the key is pressed, FIG. 5 is a block diagram showing an example of the structure of the drive circuit of the keyboard of the present invention, and FIG. 6 is a sectional view showing the manner in which the key is pressed in the keyboard. A top view showing an example, FIG. 7 is a diagram showing an example of the mode of operation when a key of the keyboard is pressed, and FIG. 8 is a timing diagram of the operation of the drive circuit shown in FIG. 5 when a key of the keyboard is pressed. It is a diagram showing an example of a chart. MP...Front plate, KPR...Key identification symbol, XP,
YP...pattern board, XPTN, YPTN...conductor strip pattern, RAX, RAY...resistance array, X0~
X4, Y0 to Y3...output terminal, GP...pressure-sensitive conductive rubber sheet, KB...keyboard, F...fingertip, XON, YON...control signal, TRX, TRY...
Transistor, DSL...Analog data selector, ADC...Analog-to-digital converter, NV...
...Discrimination output signal.

Claims (1)

[Scope of Claims] 1. In a small keyboard in which a plurality of key switches are arranged in a matrix, a plurality of key contact points are assigned to each of the plurality of key switches, and when the key switch is pressed, a short circuit among the key switches pressed is A small keyboard characterized in that the key switch with the largest number of pressed key contacts is determined to be the key switch that was pressed. 2. The small keyboard according to claim 1, in which the plurality of key contacts are connected to a first conductor line in which a plurality of first conductor wires extending parallel to each other are arranged.
an insulating sheet, a second insulating sheet on which a plurality of second conductor filaments are arranged that intersect with the plurality of first conductor filaments and extend parallel to each other;
A compact device comprising a conductor line and a pressure-sensitive conductive sheet interposed between the first insulating sheet and the second insulating sheet so as to be in contact with the first conductor line. keyboard.