Key, input unit using such key, and control system comprising such input unit and electronic apparatus acoustically connected to such input unit

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a control system for an electronic apparatus such as an information processing unit, an input unit for inputting data into this electronic apparatus and a key for use in this input unit.

2. Description of the Related Art

Keyboards are conventionally used as data input units for entering data into information processing units (hereinafter referred to as IPUs).

In general, such a keyboard is connected to an IPU through a cable or the like. A plurality of keys are provided on the keyboard. The respective keys work as electric switches. When a user depresses a key, a predetermined signal for identifying that key is generated. This signal is transmitted to the IPU through the cable.

Since the conventional keyboard is connected to the IPU through the cable, it has the disadvantage that the distance between the IPU and the keyboard is bound by the length of the cable, that is the keyboard cannot be located at a longer distance from the IPU than the length of the cable, reducing the usability of the keyboard.

In view of the above disadvantage, a prior art system for dispensing with any such cable for connecting a keyboard to an IPU by acoustically connecting the keyboard to the IPU is disclosed in Japanese Patent Application Laid-Open No. Sho 58-132834. This prior art system is shown in FIG.

10

.

Referring to

FIG. 10

, a keyboard

80

has a plurality of keys (not shown), keyboard circuit

81

for producing a digital signal corresponding to the depressed key when each of the keys is depressed, a converter

82

for converting this digital signal into a signal of a unique frequency, an amplifier

83

for amplifying the signal converted by the converter

82

, a speaker

84

driven by the signal amplified by the amplifier

83

to generate an acoustic signal (i.e., a sound), and a battery

85

for transmitting an electrical power to these components.

An IPU

90

has a microphone

91

for receiving the acoustic signal generated by the speaker

84

and sending this acoustic signal to an amplifier

92

, which then amplifies the acoustic signal, a converter

93

for converting the acoustic signal amplified by the amplifier

92

into a digital signal on the basis oh the frequency of the amplified acoustic signal, a control circuit

94

for controlling the IPU

90

, a display unit

95

for displaying data, a power supply controller

96

for supplying electrical power to the IPU

90

and a power supply line

97

connecting the controller

96

to the commercial power supply source (not shown).

As described above, according to this prior art system, the keyboard and the IPU are acoustically connected to each other to thereby dispense with any cables for connecting the keyboard to the IPU.

However, in the prior art system, the keyboard

80

must be supplied with electrical power by the battery

85

. Where the electrical charge stored in the battery

85

has run out, the system has the disadvantage that it is necessary for the user to perform a troublesome operation of replacing the battery

85

for a new one, or recharging the battery

85

if it is rechargeable battery.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an input unit that does not require any supply of electrical power, a key used in this input unit and a controlling system using the input unit for control an electronic apparatus.

According to an aspect of the present invention, there is provided a control system including an input unit provided with a plurality of keys, and an electronic apparatus, said system comprising: said keys each including: a key top, a sound generating mechanism connected to said key top for generating a sound, proper to said key, without any electrical power supply when said key top is depressed, and an outer sleeve accommodating said sound generating mechanism and having an opening portion for outputting said sound to the outside so that said sound can be received by said electronic apparatus; and said electronic apparatus including: a receiving means for receiving said sound, and a converting means for converting said sound that has been received by said receiving means, to a string of specific digital data row corresponding to said sound.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1

is a cross-sectional view showing a keyboard provided with a plurality of keys;

FIG. 2

is a perspective view of the back side of a keyboard;

FIG. 3

is a block diagram showing an IPU;

FIG. 4

is a view showing a positional relationship between the keyboard and the IPU;

FIG. 5

is a cross-sectional view showing a first type of key;

FIG. 6

is a cross-sectional view showing a second type of key;

FIG. 7

is a cross-sectional view showing a third type of key;

FIG. 8

is a cross-sectional view showing a fourth type of key;

FIG. 9

is a cross-sectional view taken along the line A—A of

FIG. 8

; and

FIG. 10

is a view showing a prior art system disclosed in Japanese Patent Application Laid-Open No. Sho 58-132834.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will now be described referring to the accompanying drawings.

According to the present invention, an electronic apparatus (such as IPU or a household appliance) and an input unit (such as a keyboard or a remote controller) are acoustically connected to each other without electrically connecting the electronic apparatus and to input unit through any cable, to transmit data obtained by user's depression of keys provided on the input unit by to the apparatus.

An embodiment of the present invention comprises an electronic apparatus and an input unit for transmitting data to the electronic apparatus.

In the following description, a keyboard and an IPU are taken as examples of the input unit and the electronic apparatus, respectively.

First of all, a keyboard will be described referring to

FIGS. 1 and 2

.

FIG. 1

is a cross-sectional view showing a keyboard

10

provided with a plurality of keys.

FIG. 2

is a perspective view of the back side of the keyboard

10

.

Referring to

FIGS. 1 and 2

, each of the keys includes a key top

11

having a top surface on which its function is indicated, a sound generating mechanism

12

for generating a sound having a unique frequency associated with one of the keys, and an opening portion which is formed in the bottom of the sound generating mechanism

12

and through which the sound generated by the sound generating mechanism

12

emitted into a resonating box

14

. The opening portions

13

of the keys are in communication with the single resonating box

14

.

The sound emitted into the box by the sound generating mechanism

12

is in turn emitted outside of the keyboard

10

through an opening portion

15

formed in the back side of the keyboard

10

.

An IPU will next be described referring to FIG.

3

.

Referring to

FIG. 3

, an IPU

30

includes a microphone

31

for detecting the above-described sound emitted from the opening portion

15

of the keyboard

10

and converting the sound into an electric signal, an amplifier

32

for amplifying the electric signal, a band-pass filter

33

for removing noise from the amplified electric signal, a frequency counter

34

for measuring the frequency of the sound emitted from the keyboard

10

based on the electric signal from which the noise has been removed, and a control unit

35

for converting the frequency measured by the frequency counter

34

into a predetermined key code (a string of digital data). For this purpose, the control unit

35

includes a table in which the frequencies of the sounds generated from the keys and key codes associated with those frequencies are registered.

Here, when the key top of a plurality of key are simultaneously depressed, a combined sound of a plurality of sounds is emitted from the keyboard

10

.

In this case, it is necessary to register the frequency of this combined sound and a key code associated with that frequency in the table in advance.

Otherwise, it is also possible to provide a mechanism for analyzing the combined sound in the IPU

30

, identify the frequencies which constitute the combined sound, and make the control unit

35

convert the combined sound into a key code associated with the combination of those identified frequencies.

Further, in the case where after the key top of a certain key (for example, corresponding to a “SHIFT” key of a well-known ordinary keyboard) has been depressed and a sound generated by the depression of this key top (hereinafter referred to as a specifies sound) has been received by the IPU

30

, another key top is depressed and a sound generated by the depression of this key top (hereinafter referred to as a regular sound) is received by the IPU

30

, the control unit

35

may produce a specific key code on the basis of the sequential reception of the frequencies of the specific sound and the regular sound.

In this case, after the IPU

30

has received the specific sound, if it does not receive any the regular sound (i.e., no key top is depressed) during a predetermined period of time, the control unit

35

may operate as if the IPU

30

had not received the specific sound.

Alternatively, if the IPU

30

receives a sound generated by the depression of the key top of a cancellation key after it has received the specific sound, the control unit

35

may operate as if the IPU

30

has not receive the specific sound.

The installation relationship between the keyboard

10

and the IPU

30

will next be described referring to FIG.

4

.

Referring to

FIG. 4

, the opening portion

15

of the keyboard

10

is directed toward the microphone

31

.

Here, if a microphone having a strong orientation is used as the microphone

31

, the voices of people around the IPU and sounds generated from peripheral units which are in operation can be prevented from being picked up by the microphone, i.e., undesired data can be prevented from being entered into the IPU

30

.

Also, by applying a sound absorbing material over the casing of the keyboard

10

so that sounds are emitted only from the opening portion

15

of the keyboard

10

, not the casing of the keyboard

10

, the picking-up of the such sounds by the microphone of another near-by IPU being used by another user can be prevented.

The construction of various keys used as the keys in the keyboard

10

will next be described.

First of all, a first type of key will be described referring to

FIG. 5

showing a cross sectional view illustrating the first type of key.

Referring to

FIG. 5

, the first type of key includes a key top

11

to be depressed by a user, a pump

112

fixed to the key top

11

, a whistle

113

in communication with the pump

112

and an outer sleeve

114

accommodating the pump

112

and the witstle

113

.

The air within Pump

112

is compressed upon the depression of the key top

11

to bring part of the air into the whistle

113

. As a result, the whistle

113

generates a sound with the air sent in.

The sound generated by the whistle

113

can be changed the shape, the material or the like of the whistle

113

. thus, a plurality of keys can generate different sounds, respectively, to send different data to the IPU

30

.

The pump

112

may be formed of plastic, rubber or the like, and the whistle

113

may be formed of plastic, metal or the like.

Incidentally, the generated sound is emitted to the outside of the keyboard

10

through the above-described resonating box

14

and received by the microphone

31

of the IPU

30

. This also applies the types of key-s to be described below.

description will be next given of a second type of key referring to FIG.

6

.

Referring to

FIG. 6

, the second type of key includes a key top

11

to be depressed by a user, a hammer

222

secured to the key top

11

, a tuning fork

223

, a spring

225

, a support member

226

and an outer sleeve

224

for receiving these components.

Incidentally, the above-described opening portion

13

is formed in the outer sleeve

224

. This also applies to the type of key-s to be described bellow.

The tuning fork

223

is fixed to the outer sleeve

224

and generates a sound upon the collision with the hammer

222

which comes down upon the depression of the key top

11

by the user.

One end of the spring

225

is fixed to the bottom of the outer sleeve

224

, and the other end is connected to the lower end of the support member

226

. The spring

226

is made of a material which can be compressed and restored. This also applies to the types of keys to be described bellow.

The upper end of the support member

226

is connected to the key top

11

.

With such a construction, the hammer

222

comes down on the depression of the key top

11

by the user and collides with the tuning fork

223

so that the tuning fork

223

generates a sound. At this time, the spring

225

is compressed by the support member

226

in response to the user's depression of the key top

11

. Thereafter, the key top

11

goes up to the original position due to the returning force of the spring

225

when the user stops the depression of the key top

11

.

The sound generated by the key can be changed by changing the shape, the material or the like of the hammer

222

and those of the tuning fork

223

. The hammer

222

may be formed of wood, hard rubber, metal or the like and the tuning fork

223

may be formed of metal.

A third type of key will next be described referring to FIG.

7

.

Referring to

FIG. 7

, the third type of key includes a key top

11

to be depressed by a user, an inner sleeve

332

directly connected to the key top

11

, in intimate contact with the side wall of an outer sleeve

334

, generating a frictional sound as a result of the frictional contact with the side wall, and a spring

335

.

One end of the spring

335

is fixed to the bottom of the outer sleeve

334

, and the other end is connected to the bottom of the inner sleeve

332

. Further, an air vent hole

333

through which part of the inner air compressed by the inner sleeve

332

coming down goes out is formed in the outer sleeve

334

.

With such a construction, the inner sleeve

332

comes down upon the depression of the key top

11

by the user. At this time, the inner sleeve

332

is brought into frictional contact with the side wall of the outer sleeve

334

to generate a frictional sound.

The sound generated by the key can be changed by changing the shape, the material or the like of the inner sleeve

332

and those of the outer sleeve

334

.

A fourth type of key will next be described referring to

FIGS. 8 and 9

.

Referring to

FIG. 8

, the fourth type of key includes a key top

11

to be depressed by a user, a support member

441

, a spring

445

, a tensional arc

446

, and an outer sleeve

444

accommodating these components.

One end of the support member

441

is connected to the key top

11

, and the other end is fixed to the spring

445

. The support member

441

has a hollow portion

442

in the middle. A projection

443

protrudes from the member

441

into the hollow portion

442

.

Also, referring to

FIG. 9

, the tensional arc

446

is provided in the hollow portion

442

so that a string

447

may come into contact with the projection

443

. The tensional arc

446

is fixed to the outer sleeve

444

. Incidentally, before the key top

11

is depressed, the projection

443

is located above the tensional arc

446

.

With such a construction, the projection

443

of the support member

441

comes down upon the depression of the key top

11

by the user to flick the string

447

to thereby generate the sound.

The sound generated by the key can be changed by changing the diameter and the tension of the string

447

, and the shape, the material or the like of the projection

443

.

As described above, the present invention has the effect that an electronic apparatus, such as an IPU or a household appliance, and an input unit such as a keyboard or a remote controller can be acoustically connected to each other without electrically connecting the electronic apparatus and the input unit.

In addition, the present invention also has another effect. In a prior art input unit (such as a well-known ordinary keyboard) having an electrical circuit provided with electrical contacts detecting depressed keys when they are depressed by a user, since a positional relationship between each of the keys and corresponding electrical contact is fixed, not changeable, the input unit does not allow the user to change the key layout on the input unit.

On the other hand, since the input unit of present invention need not and does not have such an electrical circuit, and each key is electrically and functionally independent of the other keys, it is possible to flexibly change the layout of the keys on the input unit.