JPS62251917A - Keyboard device - Google Patents

Abstract

PURPOSE:To recognize which key is depressed without unnecessary scanning by monitoring the first contacts of plural keys arranged as prescribed and discriminating states of the second contacts interlocking with said contacts in accordance with monitor results. CONSTITUTION:The first contacts 11-19 corresponding to 9 keys of a keyboard part 10 are connected in parallel, and a monitor voltage, for example, 0V is outputted and depression of any key is monitored by a monitor means 20 when the contact corresponding to said key is turned on. The second contacts 1-9 which interlock with contacts 11-19 respectively and are arranged in a matrix are scanned by signals (e), (i), and (g) in accordance with the monitor result, and the depressed key is discriminated in a discriminating means 21 by one of output signal lines (b)-(d). Contacts are scanned only when any key is depressed, and the depressed key is recognized without scanning always contacts unnecessarily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a keyboard device, and more particularly to a keyboard device that can be used as an input means for a wide range of devices such as computers and word processors.

[Conventional technology]

In devices such as computers and word processors, keyboard devices are used as the most common input means. This keyboard device has a plurality of keys arranged at predetermined positions, and when any key is pressed, the pressed key is identified.

FIG. 1B shows an example of the configuration of a keyboard section of a conventional general keyboard device. Here, for convenience of explanation, a keyboard having nine keys from the first key to the ninth key will be described. Contacts 1 to 9 correspond to each key, and contacts 1 to 9 are normally open contacts that close when the corresponding key is pressed. Contacts 1 to 9 are arranged in a 3×3 matrix as shown in the figure, and signal lines b to g are wired as shown in the figure.

To find out the state of each key, for example, it is sufficient to sequentially apply a signal to the signal lines e, f, and g, and check whether or not this signal is detected on the signal lines b1c and d. If no signal is detected, it means that no key is pressed. For example, if a signal is detected on signal line C when a signal is applied to signal line e, the key corresponding to contact 4 is pressed. This will show that it is being done. Therefore, if a scanning operation is performed to give a signal to the signal lines e-H and a signal is detected on the signal lines b-d, it is possible to know that any key has been pressed and which key has been pressed. be able to.

[Problem that the invention seeks to solve]

The above-mentioned conventional device has the disadvantage that scanning operations must be performed at all times. That is, unless the operation of sequentially applying signals to the signal line e-4 is continued, it is not possible to recognize that a key has been pressed. Even if no key is pressed for a certain period of time, the scanning operation continues continuously during this period. Generally, in a keyboard device, there are various processes that must be performed in parallel with the key scanning operation, such as generating a ΔSCM code based on a pressed key and transmitting the generated code to a host device. However, with conventional devices, scanning operations must be performed constantly.
A problem has arisen in that the processing speed of various parallel processes other than the scanning operation is reduced, resulting in the processing speed of the keyboard device as a whole becoming slower.

SUMMARY OF THE INVENTION An object of the present invention is to provide a keyboard device that can eliminate unnecessary scanning operations for key states and improve processing speed.

[Means for solving problems]

The present invention provides a keyboard device in which two contacts are provided that open and close depending on whether or not each key is pressed, and each key is arranged at a predetermined position. is detected to be in the pressed state, and only when this detection occurs, the identification means checks the state of the other suspect key to identify which key is in the pressed state. This eliminates unnecessary scanning operations and improves processing speed.

〔Example〕

The present invention will be described below based on illustrated embodiments.

FIG. 2 is a block diagram of an embodiment of the keyboard device according to the present invention. This device has a keyboard section lO5 monitoring means 20 and an identification means 21. Keyboard part 1
In this example, 0 represents nine keys, first contacts 11 to 19 and second contacts 1 to 9 corresponding to each of the nine keys, and signal lines a to g wired between these contacts. It consists of

These configurations are shown in detail in FIG.

FIG. 1 Δ is a circuit diagram showing the configuration of the first contact. The first contacts 11 to 19 are normally open contacts connected in parallel with each other, and the +5■ power supply and the 0■ power supply are connected via a resistor 22. connected between. In addition, the first contacts 11 to 19 and the resistor 2
A signal line a is connected to the connection point with 2. on the other hand,
FIG. 1B is a circuit diagram showing the configuration of the second contact. Second
Contacts 1 to 9 are normally open contacts arranged in a 3.times.3 matrix, and are connected to signal lines b to g in exactly the same way as the contacts in the conventional device described above.

Here, the first contacts 11 to 19 and the second contacts j to 9 are normally open contacts that are simultaneously closed by pressing the first to ninth keys, respectively. For example, if the second key is pressed, contacts 12 and 2 will be closed simultaneously. Focusing on the first contact, all contacts 11 to 19 are connected in parallel, so when any one of them is closed, the potential of the signal line a drops from +5■ to 0■. In other words, if signal line a is +5■, no key is pressed, and signal line a is 0■.
If so, it indicates that one of the keys is pressed. Therefore, by monitoring the state of the signal line a, it is possible to determine whether any key has been pressed.

As shown in FIG. 2, this signal line a is connected to monitoring means 20. The monitoring means 20 monitors the state of this signal line a, and when the potential drops to QV, that is,
When any key is pressed, a scan start signal is given to the identification means 21. The identification means 21 normally does not perform any operation, but upon receiving a scan start signal, it starts a scan operation. This scanning operation may be the same as that of the conventional device. That is, detect the state of the signal line bScSd when signals are sequentially applied to the signal lines c, f, g,
It identifies which key is being pressed. This corresponds to the operation of detecting the states of the second contacts 1 to 9 shown on the first father's day, and is similar to the principle in the conventional device. The identification means 21 stops the scanning operation when the identification of the pressed key is completed.

As described above, the identification means 21 performs a key scanning operation only when a key is pressed. Therefore, as long as no key is pressed, the scanning operation of the identifying means 21 will not cause a delay in other processing.

In the above-mentioned embodiment, normally open contacts connected in parallel to each other are used as the first contacts, but the present invention is not limited to such a configuration. Any structure that can detect that a key has been pressed may be used. Furthermore, the second contact is not limited to the configuration shown in this embodiment, and may be of any configuration as long as it allows identification of the pressed key.

〔Effect of the invention〕

As described above, according to the present invention, in the keyboard device,
The first one to monitor whether any keys are pressed.
contacts and a second one to identify which key was pressed.
Since each key is provided with a contact point, it is possible to eliminate unnecessary scanning operations for key states and improve processing speed.

[Brief explanation of drawings]

1A and 1B are block diagrams of a first contact and a second contact, respectively, of a keyboard device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a keyboard device according to an embodiment of the present invention. It is. 1-9...second contact, 10...keyboard section, 11-19...first contact, 20...monitoring means, 21. ...Identification means, 22...Resistance. Applicant: NEC Co., Ltd. NEC Engineering Co., Ltd. Agent

Claims (1)

[Claims] 1. A plurality of keys arranged at predetermined positions, and a first contact and a second contact provided for each of the keys, which open and close depending on whether or not the key is pressed; monitoring means for monitoring the state of the first contact and generating a signal when any one of the keys is pressed; 1. A keyboard device comprising: identification means for checking the state of two contacts and identifying which key is in a pressed state. 2. The keyboard device according to claim 1, wherein the first contacts for each key are normally open contacts connected in parallel.