JPH03134725A - Keyboard - Google Patents

Abstract

PURPOSE:To miniaturize the keyboard and to improve its durability and sense of use by using an extremely thin touch panel on which there is no mechanical contact at all. CONSTITUTION:On a touch panel 31, the upper cover 30 is placed, and on the upper cover 30, a function of a key, etc., are printed and it is attached closely to the touch panel 31. As for the touch panel 31, there is no mechanical contact at all, its thickness is only a size of several mm and there is no restriction and the surface, therefore, the upper cover 30 can be placed in such a way. On the other hand, in the lower case 37, there are electronic parts such as a control IC 36, etc., and to the control IC 36, signal lines 32-35 from the touch panel 31 are connected, and a connecting line 38 is connected to a host computer and transmits a signal. In such a way, since the touch panel 31 whose thickness is extremely thin and in which there is no mechanical contact at all is used, the keyboard which is miniaturized, excellent in its durability and combined and provided with flexible applicability can be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a keyboard using a touch panel.

[Prior Art] A keyboard, which is generally referred to as a keyboard, has a large number of switches arranged like the keys on a typewriter, and is widely used as a computer terminal. Most of the time, mechanical contact type switches are used that have a certain amount of stroke when inputting. Additionally, some use seat type switches with a small stroke.

[Problems to be Solved by the Invention] Since general keyboards use mechanical contact type switches, the switches cannot be made very small, and the keyboard itself is large and difficult to make particularly thin. Also, the keys require a certain amount of force to press, so if you use them for a long time, you may get tired or your fingers may become weak. Since the pressing force varies depending on the type of keyboard, it may feel strange when using different types of keyboards. Especially in low-priced models, the feel of the keys when pressed is often clearly inferior to that of high-end models.

Additionally, if you use a keyboard for a long period of time, frequently used keys may have poor contact because they use mechanical contact switches. At the same time, characters and symbols printed on the key covers of frequently used keys may become thin or peel off.

Even in this case, it is not possible to replace only the defective part.

Also, since the ``-'' key corresponds to the ``-'' function, it is not possible to realize multiple key functions on one keyboard without using auxiliary keys. Basically, one type of keyboard corresponds to one host computer.

The keyboard of the present invention solves the above-mentioned problems, and its purpose is to provide a keyboard that is miniaturized by using a touch panel without any mechanical contacts, and has excellent durability and flexible applicability. There is a particular thing.

[Means for Solving the Problems] (1) The keyboard of the present invention includes a touch panel in which key functions are printed on the surface of the panel and whose resistance value changes depending on the position on which the panel surface is pressed, and a terminal of the touch panel. a position detection means that applies a base 8M pressure for position detection to the touch panel, detects the voltage generated when the touch panel is pressed, and determines the pressed position on the touch panel surface from the detected voltage value;
The key input determining means determines which key corresponds to the position determined by the position detecting means, and the communication means sends a code corresponding to the key determined by the key input determining means to a host computer or the like. It is characterized by

(2) The key input determining means is characterized in that when it is recognized that the pressed position on the touch panel is correct and that a key input has been made, the user is notified by a buzzer sound.

(3) The touch panel is characterized in that the portion on which the functions of the keys and the like on the touch panel are printed is replaceable.

(4) When replacing the part of the touch panel on which the functions of the keys, etc. are printed on the touch panel, the type of the part on which the functions of the replaced keys, etc. are printed is automatically determined and the key functions are changed. It is characterized by being able to

C Effect] The principle of detecting the pressed position on the surface of the touch panel will be explained with reference to FIG. When detecting the position of the touch panel 5 in the X-axis direction in FIG. 2, a voltage is applied in the detection direction. That is, terminal 1
1 is grounded and power supply 6 is connected to terminal 10, terminal 11
The potential becomes higher as it goes from the terminal 10 to the terminal 10. When the surface of the touch panel 5 is pressed, a potential corresponding to the pressed position is generated in the voltmeter 7. For example, if you press the edge of terminal 11, the voltage of the power supply 6 will be 0
is shown.

Conversely, if you want to know the position of the touch panel 5 in the direction perpendicular to the X-axis direction in Fig. 2, ground one of the terminals 12 and 13 of the touch panel 5 and connect the other to the power supply in the same way as in the X-axis direction. Connect terminal 10 or 11 to voltmeter 7 to detect voltage. In reality, each terminal is connected to a power source or
Detection is performed by switching alternately between ground and voltmeter.

The relationship between voltage and position is shown in the graph of FIG.

If the touch panel is connected as shown in FIG. 2 and the position in the X-axis direction is to be detected, the positions XI, X2, X2, etc. will be detected as shown in the graph in FIG.
X3. As the value of X4 increases,
The corresponding voltage value V,, v,,.

V3. V4 will also be proportional to X. When the range of area 9 is pressed, the voltage generated is v1 to v2, and when the range of area 8 is pressed, the voltage generated is v3 to V4.

The pressed position can be estimated from the voltage generated in this way.

[Example] Hereinafter, the keyboard of the present invention will be described in detail based on an example.

FIG. 1 is a diagram clearly showing the basic structure of the keyboard of the present invention.

The touch panel 1 displays key functions etc. on its surface.
It is printed and the resistance value changes continuously depending on where you press the surface.

The position detecting hand 82 alternately applies a reference voltage for position detection to the touch panel 1, detects the voltage generated depending on the pressed position on the surface of the touch panel 1, and estimates the pressed position from the voltage value.

Based on the position estimated by the position detecting means 2, the key input determining means 3 determines which key corresponds to that position.

The communication means 4 encodes the key content determined by the key input determination means 3 and sends the coded content to the host computer.

FIG. 4 is a block diagram showing an example of a power supply detection circuit.

The direction from the terminal 11 to the terminal 10 is determined to be the Y direction, and the direction perpendicular thereto (the direction from the terminal 12 to the terminal 13) is determined to be the X direction.

First, the voltage supplied to the four terminals of the touch panel 5 is switched depending on the direction of detection. Terminal 10.11.12
．． 13 are switching circuits 20(7)A, respectively.

Connected to B, D, and C.

When detecting the position in the Y direction, terminal 1o is connected to the power supply, terminal 11 is grounded, terminals 12 and 13 are disconnected from the power supply system, and voltage changes are detected at terminal 13. On the other hand, when detecting the position in the X direction, terminal 13 is connected to the power supply, terminal 12 is connected to ground, and terminal 10
and 11 are separated from the power supply system and detect voltage changes at terminal 11. The terminals are switched by determining whether the CPU 25 detects the X or Y direction and instructing the switching circuit 20 to switch the terminals.

A multiplexer 21 selects either the X or Y voltage to be detected, and the A/D converter 22 converts it into a digital value. A sampling clock for conversion is provided by a clock control section 23, and a reference voltage is provided by a reference voltage circuit 24. In this way, the CPU 25 can switch to the desired direction and perform A/D conversion on the voltage value corresponding to the position in that direction.

FIG. 5 is a diagram showing an example of the structure of the keyboard of the present invention.

It consists of three main parts. First, the touch panel 31 and signal lines 32, 33, 34 for position detection.
It is 35. An upper cover 30 is placed on top of the touch panel 31. The functions of the keys, etc. are printed on the upper cover 30, and this is attached exactly to the touch panel 31. However, depending on the situation, it may be possible to remove it or replace it with another top cover. The touch panel has no mechanical contacts, is only a few millimeters thick, and has no restrictions on its surface, so the top cover 30 can be placed on it in this way.

On the other hand, the lower case 37 includes electronic components such as a control IC 36 that performs position detection, signal transfer, etc.
are the signal lines 32, 33, 34 . of the touch panel 31 .
35 are connected. Further, the connection line 38 connects to the host computer and transmits signals.

Since the thickness of the touch panel that serves as the key is extremely thin, it is possible to achieve an overall shape that is much thinner than the method using a mechanical contact switch with a large stroke.

FIG. 6 is a diagram illustrating an example of a mechanism for detecting replacement of the upper cover.

In this example, an example will be described in which replacement of the top cover is detected in a non-contact manner.

A hole is made in a part of the upper cover 30 as shown in FIG. 6(a). The touch panel 31 is made of a transparent material. A plurality of phototransistors 44 to 47 are installed on a substrate 43 behind the touch panel 31. Of the light beams such as external light, only light beams 1JA 40 and 41 pass through the hole and reach the phototransistors 44 and 46, respectively, and the phototransistors are turned on. FIG. 6(b) shows an example of the circuit, in which only the phototransistor located in the holed part of the upper cover 30 is turned on.

Therefore, by determining the position of the hole for each top cover and detecting the position of the hole, it is possible to determine which type of top cover is currently in use. However, when replacing the top cover, it is necessary to ensure that the relative positions of the top cover and touch panel do not shift.

FIG. 7 is a block diagram showing an example of the entire circuit of the keyboard of the present invention.

A switching circuit 50 connects and disconnects the four terminals of the touch panel 30 with a power source, a detection signal, and the like.

The voltage of the touch panel is digitized by an A/D converter 51 and taken in by the CPU 25.

Further, the type of the top cover 30 is determined by detecting a hole made in the top cover 30 by the top cover determination circuit 52, and sending the detection to the CPU 25 and checking with the contents of the ROM 56 to determine which top cover it is.

A buzzer 54 is provided to notify the user that a key input has been made by pressing the touch panel.

When the CPU 25 confirms the key input, the signal is sent to the amplifier 5.
3 and the buzzer 54 sounds.

The detected voltage values, intermediate calculation results, etc. are temporarily stored in the RAM 55. In addition, the ROM 56 contains the entire program, data regarding the relationship between voltage values and positions on the touch panel, and a correspondence table between pressed positions and keys.
Contains identification data for each top cover.

For the host computer, the confirmed key is coded for transmission, converted into a signal that can be transmitted by the I/F section 57, and the signal level is adjusted by the driver 58 before being sent to the connection line 3.
Send via 8.

Figure 8 is a flowchart showing an example of a series of processes from turning on the IT power to detecting and transmitting key inputs. investigate.

(Step 60) This allows it to be determined which of the tables in the ROM 56 showing the relationships between positions and keys is to be used. In other words, even if you use a different type of top cover, you can change the keyboard to have completely different functions by changing the internal data.

Subsequently, voltage values are detected in each of the X and Y directions.

(Step 61) Then, the voltage value continues to be detected until the pressed position is within the area where the key is printed (Step 62) and a corresponding key exists (Step 63).

When a corresponding key is found, a buzzer sounds to notify the user that the key input has been completed. (Step 64) Next, the corresponding key is encoded for transmission.Step 65) The host computer is interrupted and the contents are sent.

(Step 66) This process is repeated until the power is turned off.

[Effects of the Invention] As described above, the keyboard of the present invention uses a very thin touch panel without any mechanical contacts, so that
There are no problems such as poor contact, and input can be made by simply pressing lightly on the touch panel, making it possible to obtain an extremely thin keyboard with excellent durability and usability.

By notifying the user with a buzzer each time a key input is confirmed, reliable input can be achieved at all times.

By replacing the top cover that describes the functions of the keys on the touch panel, you can prevent dirt and wear from long-term use. Furthermore, if you use a top cover with different printed key functions, it will automatically detect which top cover you are using and change the detection position and key correspondence according to the top cover you are using. By doing so, it is possible to realize multiple functions with one keyboard simply by replacing the top cover.

[Brief explanation of the drawing]

Figure 1 is a diagram clearly showing the basic configuration of the keyboard of the present invention, Figure 2 is a diagram explaining the principle of position detection on the touch panel, and Figure 3 is a diagram showing the voltage generated at the terminal of the touch panel and the position on the touch panel. FIG. 4 is a block diagram showing an example of a power supply detection circuit. FIG. 5 is a diagram showing an example of the structure of the keyboard of the present invention. FIG. 6 is a diagram showing the replacement of the top cover. FIG. 7 is a block diagram showing an example of the entire circuit of the keyboard of the present invention. FIG. 8 is an example of a series of processes from power-on to detecting and transmitting key inputs. FIG. 1, 5, 3 ・ ・ 6 ・ ・ 8, 9 10. 20. 21 ・22. 23 ・ 24 ・ 25 ・ 30 ・ 32. 36 ・ 37 ・ ・ 38 ・ ・ 40, 4 11, 0 1 33. 1. 31...Touch panel, position detection means, key input discrimination means, communication means, power supply, voltmeter...Area 12.13...Terminal...Switching circuit multiplexer...A/D converter clock control section Reference voltage circuit PU Upper cover 34, 35... Signal line control IC Lower case connection line 42... Light beam 43 ・ ・ Board 44, 45, 46, 47 Phototransistor 52 ・ 53 ・ 54 ・ 55 ・ 56 ・ 57 ・58 ・・Top cover judgment circuit・amplifier・buzzer・RAM・ROM・I/F section・driver and above

Claims (4)

[Claims] (1) A reference voltage for position detection is applied between a touch panel whose key functions are printed on the panel surface and whose resistance value changes depending on the position on which the panel surface is pressed, and the terminals of the touch panel, and the touch panel is pressed. position detecting means for detecting the voltage generated when the touch panel surface is pressed from the detected voltage value; key input determining means for determining which key corresponds to the position determined by the position detecting means; A keyboard comprising a communication means for transmitting a code corresponding to a key determined by a key input determination means to a host computer or the like. (2) The keyboard according to claim 1, wherein the key input determining means notifies the user with a buzzer when it is recognized that the pressed position on the touch panel is correct and a key input has been made. (3) The keyboard according to claim 1, wherein in the touch panel, a portion on which key functions and the like are printed is replaceable. (4) When replacing the part of the touch panel on which the functions of the keys, etc. are printed on the touch panel, the type of the part on which the functions of the replaced keys, etc. are printed is automatically determined and the key functions are changed. 4. The keyboard according to claim 3, wherein the keyboard is capable of