JPS61134828A - Key input device - Google Patents

Abstract

PURPOSE:To attain easily many functions with the same key by changing the function of the same key according to the push time duration of the key. CONSTITUTION:A key input device contains a keyboard 1 and a microprocessor MPU2, and the MPU2 has a primary memory 3 consisting of an RAM and an ROM. the ROM stores a control program and the RAM stores temporarily the processing data. Furthermore the RAM is used as a counter area CE where the push time width of a eky is shown. Then the key data are sent to a host computer via a circuit interface 4, and the key input is confirmed via a display device 5. The push of an optional key on the keyboard 1 is discriminated by the MPU2. Then the key data is read again when a fixed period of time passed for decision whether the same key is pushed or not. Thus the key data is decided. In such a way, the key function can e changed according to the push time width of a key. This attains many functions with the same key.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an input device, and more particularly to a key input device in which the function of a key changes depending on how long the key is pressed down.

[Prior Art] In recent years, with the advancement of semiconductor technology, the development of compact and multifunctional electronic devices has increased.

Input devices such as keyboards are also becoming smaller.

However, in the key input device of electronic equipment with multiple functions,
Since the number of keys tends to increase, efforts are being made to reduce the size of the keys by making the shapes smaller. However, the shape of the key is inevitably determined to be the minimum size considering the size of the human finger, so to avoid increasing the number of keys, it is necessary to use it in conjunction with other keys to It is designed to be functional.

For example, simply inputting the key will produce the uppercase letter AH, and inputting m+i will produce the lowercase letter a"'.

However, this method has many disadvantages, such as the number of operations required, and the need to check the current mode with shift-lock keyboards.

[Objective] The present invention was made in view of the above-mentioned drawbacks, and an object of the present invention is to provide a key input device in which the function of a key changes depending on the time the key is pressed.

[Embodiment] FIG. 1 is a block diagram of a key input device of the present invention. In the figure, l is the keyboard, 2 is the microprocessor (
(hereinafter referred to as MPU). Microprocessor 2 includes main memory 3 . The main memory 3 consists of two types of memories, RAM and ROM, and the ROM stores a control program shown in FIG. 2. On the other hand, the RAM is used not only to temporarily store processing data but also as a counter area CE that indicates the length of time the key is pressed. 4 is a line interface for transmitting key data to the host computer, and 5 is a display for confirming key input.

Now, if any key on keyboard 1 is pressed, I
Then, the M
PU2 is informed that there is a key signal. MPU2
determines which key is pressed, reads the key data again through the bus after a certain period of time, determines the key data by determining whether the same key is still in the pressed state, and then reads the key data through the 1-line interface 4. Send key data to the host computer.

More detailed operations will be explained using the flowchart of FIG. 2 showing the control flow executed by the microcomputer MPU.

In step 1 of FIG. 2, the MPU 2 uses the keyboard l.
periodically reads information from the bus through the bus. If it is determined here that there is a key input, it is determined in step 2 which key it is. Then, a specific value M is set as a count value in the counter area CE of the RAM (step 3).
, in step 4, the value in the counter area CE is decreased by 1, and it is determined whether the value has become zero (step 5).
), and in step 6, it is checked through the bus whether the same key is being pressed continuously. If it is not held down, press the first key (e.g.

For example, it is interpreted that a capital letter of the alphabet) has been input.
The key data is displayed on the display 5 (step 7), and the corresponding key data is transmitted to the host computer through the line interface 4 (step 8).

However, if it is determined in step 6 that the same key is still being pressed, the process returns to step 4, the content of the counter area CE is again subtracted by 1, and the same loop as above is repeated.

When the contents of the memory become zero in step 5, it is treated as a second key, and the process moves to step 9, where it is interpreted that the second key (for example, a lowercase letter of the alphabet) has been input and is displayed on the display 5. In step 7, the corresponding key data is sent to the host computer. - Figure 3 shows a timing chart during key input, and shows the concept of determining the key function based on the length of time the key is pressed. The example shown in the figure focuses on the alphabet “A” and the lowercase letter “a”, and the time relationship is now T1≦T2.
This is the case. If the time width is about Tl, it is processed as an uppercase letter "A", and if the time width exceeds TI and is about T2 or more, it is processed as a lowercase letter 11aH.

On the other hand, determining the key function according to the pressing time can also be realized using a circuit as shown in FIGS. 4 and 5. To summarize the configuration, FIG. 4 is a configuration diagram in which a key discrimination circuit 6 is added between the keyboard 1 and the MPU 2, and FIG.
This figure shows a detailed configuration example. In the figure, 10
corresponds to one key switch on the keyboard, 11 is an inverter circuit, 12 is an AND gate circuit, 13 is a clock generator, 14 is a 4-bit counter,
15 is a 4-bit decoder, 16 is a latch circuit that latches at a falling clock, and the output of this is connected to the input port of MPU2. To explain the operation, when the switch 10 is pressed down, the output of the inverter circuit 11 becomes HIGH, the AND gate 12 is opened, and the oscillator 1
3 is input to the clock terminal of the counter 14.

On the other hand, the output of the inverter circuit 11 is
Since it is connected to the clear terminal of 114, the switch l
When O is not pressed down, the counter 14 is cleared, and when the switch 10 is pressed down, the counter 14 starts counting. The output of the counter 14 is decoded by a decoder 15, and its output is connected to a latch circuit 16. The latch circuit is the OFF signal of the switch 10,
That is, input data is latched by a falling signal.

An example of a timing chart is shown in FIG. 6. In this example, the switch is turned off when the value of the counter 14 reaches 5, so a signal of 5 is latched in the latch circuit 16. The MPU 2 reads this signal and determines the key function based on, for example, whether the decoder output is smaller than 5, between 5 and 10, or larger than 10, etc., and displays the key data on the display 5, and also displays the key data on the line interface 4. to the host computer through.

Although the embodiments have referred to changing the key functions of character keys, there is no limitation to the types of keys to which the present invention can be applied, and it goes without saying that the present invention can also be applied to function keys.

[Effects] As is clear from the above description, according to the present invention, the function of the same key is changed depending on the length of time the key is pressed, so that the same key can be provided with multiple functions. Furthermore, since this function does not need to be realized in cooperation with other keys, a large key space can be taken up for each key.

[Brief explanation of the drawing]

Fig. ts1 is a block diagram showing an embodiment of the key input device of the present invention, Fig. 2 is a flowchart showing control of key function judgment, and Fig. 3 shows changes in key function and pressing time during key input. Timing Chart FIG. 4 is a block diagram showing an embodiment in which the present invention is implemented using a discrimination circuit, FIG. 5 is a circuit diagram showing details of the discrimination circuit, and FIG. 6 is a timing chart for key input.

Claims (1)

[Claims] A key input device comprising: a determining means for determining a key press time; and a means for determining a key function based on the time determined by the determining means.