JPS6319886B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides that even if multiple keys are pressed at the same time,
The present invention relates to a key input device that detects a newly input key.

Currently, a wide variety of key input devices are used, such as personal computers, cash registers, and familiar calculators and typewriters. These key input devices may require a multiple press function depending on the type of product in which they are used. Here, the multiple press function is a function that detects the newly pressed key even if two or more keys are pressed.For example, calculators do not need this multiple press function, but typewriters etc. The multi-press feature is needed to speed up the process and improve ease of use. This is because if the key input device prohibits multiple presses, once a key is pressed, the next key will not be input until the key is released, so the puncher must release his finger from the key once and then press the next key. This slows down the input speed and makes it very difficult to use. However, if the key input device has a multiple press function, the next key can be input without taking the trouble of removing the finger from the key, thereby improving input speed and ease of use. In order to realize the multiple press function, it is necessary to distinguish between the previous key input and the new key input. Traditionally, mechanical devices have been configured to combine gears, cams, etc., and are configured to ignore the fact that a key has been pressed as soon as the previous key input has been printed, and prepare to accept the next key. . However, with this method, it was difficult to make the product smaller, lighter, and simpler. Then came the electronic key input device.
This is a method that outputs a signal corresponding to the pressed key, and can be made small, lightweight, and simple. The biggest problem in realizing the multiple press function with this type of key input device is how to distinguish the signal of a new key from the duplicate signals that appear when two or more keys are pressed. be. In other words, when you press only one key, only the signal corresponding to that key is output, so there is no problem, but when you press two or more keys, the signals corresponding to each key overlap and become one. Since it comes out as a signal, we need to extract only the signal that corresponds to the newly pressed key. If this detection is not performed well, the circuit becomes complicated and costs increase.

The present invention solves such problems,
It is an effective means for making products smaller, lighter, simpler, and lowering costs. Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows a specific embodiment of an electronic circuit for implementing the invention. Microprocessor 1, read-only memory (ROM) with built-in programs 2, read/write memory (RAM) that can read and write data 3, decoder circuit 4
Mainly the DATA bus, ADDRESS bus,
CONTROL bus input/output ports 5, 6, 7, 9
are combined and connected to a 4 x 16 matrix type keyboard 8. Output port 5 performs key input control by driving rows of the keyboard, and input ports 6 and 7 each perform 8-bit column key detection. Key input control is from COM1 to COM4.
This is done by sequentially outputting signals to the keys, and key detection is performed for each sequence. At this time, each wire is grounded through a resistor to ensure that COM and the rows where no keys are pressed are LOW when no signal is flowing. In addition, a diode is inserted in each COM to prevent signals from flowing backward through COMs other than the one outputting the signal to output port 5 when keys in the same row are pressed at the same time.
Furthermore, rows with shift keys and repeat keys are input directly to the microprocessor 1 without passing through input ports 6 and 7, so that when only the key is pressed, it is not judged as a new key input. The processor makes the decision. The results of key detection in this manner are sequentially stored in the RAM 3. The output port 9 is provided for outputting the key input code converted by the microprocessor 1 to the outside. In addition, the ROM of 2 stores a program for detecting key inputs and identifying new key inputs, as well as other necessary programs. The method is very effective.

FIG. 2 shows how detected keystrokes are stored in RAM. First, a signal is output to COM1, and the 8-bit segment signal detected at input port 6 is stored in the first column, and then the 8-bit segment signal detected at input port 7 is stored in the second column. This operation
This is performed sequentially for COM1 to COM4 to obtain the memory contents as shown in Figure 2.

FIG. 3 is a general flowchart of an embodiment of the present invention. In this example, three or more presses are not allowed. This is a problem with the structure of the keyboard, and will be explained later with an example shown in FIG. Now, in FIG. 3, when the circuit is first powered on, the output ports, registers, and other counters are initialized at 31. Next, at 32, a row of the keyboard is driven through the output port 5 (FIG. 1), and along with this, a column of the keyboard is detected through the input ports 6 and 7, and the results are stored in the RAM 3. Next, at 34, the key input data detected at 32 is read from the RAM 3, and it is determined whether the number of input keys is three or more. the result,
If the number of inputs is not three or more, it is determined in step 35 whether or not the input is a new input. Since this method is the object of the present invention, a specific example will be shown in FIG. 6 and a separate explanation will be added. If the key is determined to be a new key, the code is converted for output and output. Further, a location is prepared in the RAM 3 to store the previous key input, and at 38, the current key input and the previous key input are exchanged and the current key input is stored in that location. The storage format is the same as that shown in FIG. 2, and the old and new data are exchanged using data before code conversion. 39 timers are
It is provided for timing purposes.

FIG. 4 shows a portion of a matrix type keyboard. A black circle indicates that a key is pressed. The reason why triple pressing or more is not allowed in the embodiment shown in FIG. 3 will be explained below. for example,
Suppose that three keys are pressed as shown in a to cause a current (signal) to flow through COM1. Tracing the path of the signal at this time, first a signal is detected at A because the 1A key is pressed, and then a signal is detected at C because the 1c key is pressed. Also, since 3c is pressed, the signal tries to flow into COM3, but since a diode is inserted as shown in Figure 1, the signal is stopped here. Therefore, when sending a signal to COM1, A,
There is no problem because the signal is detected in C and the key that is actually being pressed is detected. However,
If the signal comes from COM3, 3C,
Since the 1C and 1A keys are pressed, the signal is
The signal flows along the route COM3→3C→C1C→COM1→1A→A, and signals are detected at A and C as well. Therefore, it appears as if the 3A key is being pressed. Therefore, in this type of keyboard, triple pressing or more must be prohibited. However, if the keyboard itself is modified to some extent, such as by inserting a diode between each row as shown in b, this problem can be solved and multiple presses can be made.

That is, although the present invention has been described using diodes, for example in FIG. It is assumed that the key input device is a type that cannot be used.

Here, I will explain it in a little more detail.
The n-bit key information obtained by scanning multiple keys is K (b ₀ , b ₁ , ..., b _o ) {b _o is a bit element: bo = ₀
or 1}.

Further, the key information when key a, key b, and key c are pressed individually is as follows.

Key a...K _a (b _i ) Key b...K _b (b _j ) Key c... K _c (b _k ) i, j, and k are subscripts of the bit elements and are arbitrary numbers in the range of 0 to n. For example, assume that K _a (b _i ) represents key information where b _i is logic "1". Next, the first
Assume that the key information of the second key information is x, and the second key information is y.

(1) x=K _a (b _i ): Only key a is pressed y=k _a+b (b _i , b _j ): Keys a and b are pressed simultaneously x○+y=K _a (b _i )○+K _{a +b} (b _i , b _j ) (...calculate the exclusive OR of x and y) = K (b _j ) K (b _j )・y=K (b _j )・K _a+b (b _i , b _j )=K(b _j
) =K _b Therefore, only the new key b has been detected.

(2) x=K _a+b (b _i , b _j ): Pressing keys a and b simultaneously y=K _a+b+c (b _i , b _j , b _k ): Pressing keys a, b, and c simultaneously Simultaneous press x○+y=K(b _k ) K(b _k )·y=K(b _k )=K _c Therefore, only the new key c is detected.

(3) x=K _a+b (b _i , b _j ): Keys a and b are pressed simultaneously y=K _a (b _i ): Key b is off +○+y=K(b _j ) K(b _j )・y=K(b _p ) Therefore, since the bit element is 0, it is detected that there is no new key.

As described above, the present invention has a simple circuit and very good operability in a multiple-press input device.

FIG. 5 shows an example of the code conversion of FIG. 36. The first and second bits contain repeats detected by the microprocessor itself, respectively.
Insert the shift code, and the third and fourth bits are used for the four COM conversion codes. The remaining 4 bits are used as a conversion code for key segment input data. If code conversion is performed in this way, all key inputs can be covered with 8 bits, which is very convenient and improves efficiency.

FIG. 6 is a detailed view of FIG. 35 and is a specific example of the present invention. First, in 61, the corresponding bytes of the previous key input data and the current key input data stored in the memory are read out, and 6
In step 2, take the exclusive OR of both. The result of the exclusive OR is determined at step 63, and if the value is all 0, there is no change in the 8 bits between the current key input and the previous key input. In other words, it indicates that no new key has been pressed within those 8 bits. Next, in step 64, it is determined whether all bytes, in this case 8 bytes, have been processed. Here, if the determination is YES, it goes without saying that the current key input is the same as the previous key input. If the judgment is NO, in order to proceed to the next byte check, the counters indicating the addresses containing the new and old key data are incremented by one at 65, and the process returns to 61 to repeat the above-described operation. Also, if it is determined NO in 63, it is 8.
Indicates that a new key has been pressed within the bit. The result of exclusive OR is only the bits that differ between the previous keystroke and the current keystroke.
Since the result is HI, a new key input can be detected by logically ANDing the result with the current key input at 66. Also, by releasing one of the double-pressed keys, the previous key input and current key input will be different.
By performing a logical product, the current key input is canceled out and the current key input is not determined to be a new key input.

The invention will now be described in more detail. First, in Figure 4a, key a corresponding to the intersection of COMI and A is pressed, and with key a pressed,
The method for determining that key b is a new key input when key b corresponding to the intersection of COMI and C is pressed is as follows.

After calculating the exclusive OR (0010) of key a (1000) and key a + b (1010), calculating the logical AND of the exclusive OR (0010) and the current key, that is, key a + b (1010), (0010 ), and this logical product (0010) indicates key b (0010). Even if key b is pressed while key a is pressed, the judgment of key input is the same as when key a is pressed and then key b is pressed.

FIG. 7 is a diagram corresponding to claims of the present invention. In FIG. 7, 101 is a first key scanning signal generation circuit that generates a signal when the first key is scanned;
02 is a second key scanning signal generation circuit that generates a signal when the second key is scanned; 103 is a first key information storage circuit that stores the output signal from the first key scanning signal generation circuit 101; and 104 is a a second key information storage circuit that stores an input signal when the second key is scanned while the first key is being scanned; 105 is the first key information storage circuit 103;
output signal from and the second key information storage circuit 1
106 is the exclusive OR circuit 1 which performs an exclusive OR with the output signal from 04;
107 is a new input key that detects a new input key from the output signal from the AND circuit 106; This is a detection circuit.

As described above, the present invention relates to a key input device in which the same bit element of the key information does not simultaneously become the first logic state, for example, logic "1" in different individual key inputs. and,
According to the present invention, it is possible to easily detect a new key input in the multiple press function using only a software method, so the circuit does not become complicated, and various operations can be performed simply by adding a program, so the range of application is wide. In addition to having advantages such as a wide space, it is also possible to reduce the size and weight. Furthermore, the present invention can also be implemented in terms of hardware using logic circuits and the like. The present invention can be particularly effective for electronic typewriters. In addition, as in the present invention, even if keys are pressed simultaneously, that is, even if a new key is input over the previous key, it is determined that a new key input has been made at the time the new key input is performed. This also has the effect of allowing the user to input keys in a very natural way.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention. 1...Microprocessor, 2...Read-only memory (ROM), 3...Read/write memory (RAM), 4...Decoder circuit, 5, 9...Output port, 6,7...Input port, 8...4x16 matrix method keyboard. FIG. 2 shows a method for storing key inputs in memory in an embodiment of the present invention. FIG. 3 is a schematic overall flowchart of an embodiment of the present invention.
FIG. 4 shows a portion of a matrix type keyboard. FIG. 5 is an example of code conversion of FIG. 36. FIG. 6 is a detailed view of FIG. 35 and is a specific example of the present invention. FIG. 7 is a diagram corresponding to claims of the present invention.

Claims (1)

[Claims] 1 Among the same bit elements of the key information of the individual key due to the input of different individual keys, only the bit corresponding to the key information of the individual key is independently
a first key information storage circuit for storing first key information obtained by scanning a first key; a second key information storage circuit that stores second key information obtained by scanning a second key while the key is being scanned; and the first key information output from the first key information storage circuit. and the second key information output from the second key information storage circuit; an output signal from the first means and the second key information storage circuit; and a detection circuit for detecting the second key as a newly input key based on the output signal from the second means. A key input device characterized by: