JPH06289967A - Method and device for discriminating depressed key for keyboard - Google Patents

Abstract

PURPOSE:To convert the depression of a key into an electric signal without using a mechanical connection point. CONSTITUTION:An optical beam 28 which is frequency-shifted from a semiconductor laser oscillator 12 is divided into two optical beams 28a and 28b in a half mirror 38. The first beam 28a is defined as reference light and the second beam is defined as reflected signal light reflected on a key reflector 14. Reference light and interference signal light 40 is generated from the second beam. A beat frequency is detected and the key generating reflected signal light (depressed key) is discriminated from the electric signal corresponding to the beat frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a key input into an electric signal and discriminates the key input from the electric signal. Regarding the device.

[0002]

2. Description of the Related Art As input means for a computer such as a personal computer (personal computer) or a word processor (word processor), for example, a large number of keys such as push buttons are provided in several lines. Keyboards regularly aligned over
Do is known. In the keyboard, generally, an operator manually inputs (pushes) a key for input.

In such a keyboard, normally,
A driving key discriminating device is built in the keyboard, and the driving key discriminating device converts the driving of the key into an electric signal and discriminates the driven key from the electric signal. Then, the signal from the driving key discrimination device is
As input information from the board, it is input to a central processing unit (CPU) such as a personal computer main body and appropriately processed.

As a driving key discriminating device for converting the driving of a key into an electric signal, for example, a pair of contacts which can contact each other are provided, for each key, on the side of the key and the side of the keyboard side. A contact-type configuration provided in each of and is known.

In such a structure, the driving of the key is converted into an electric signal by the contact between the pair of contacts due to the driving of the key, and the driven key is discriminated from the electric signal.

[0006]

[Problems to be Solved by the Invention] Contact type driving key
In the discriminating device, the pair of contacts repeatedly come into contact with and separate from each other every time a key is driven, so that the pair of contacts is easily worn. Particularly, in a key that is frequently used, contact failure is likely to occur due to deformation, deterioration or the like of the contact surface. The contact failure of the contact causes a malfunction (erroneous input) such as non-input of a signal or duplicate input at the time of driving a key, which deteriorates operability.

Further, in the known structure, a pair of contacts is provided for each key. That is, in one keyboard, a pair of contacts are required in the same number as the keys on the keyboard, which is a considerable number.

Here, in order to form an output path of an electric signal generated by driving a key, the contacts on the keyboard side are mounted and fixed on a printed circuit board or the like by soldering. There is. In the process of assembling the keyboard, soldering the contacts to the printed circuit board requires the same number of working steps as the key, which complicates the process of assembling the keyboard.

Since a pair of contacts can be brought into contact with and separated from each other, and a number of constituent members for outputting an electric signal are required respectively in a number corresponding to the key. Therefore, the number of parts for constructing the keyboard increases, and the configuration becomes complicated and the keyboard becomes expensive.

It is an object of the present invention to provide a method for determining a key for driving a keyboard that generates an electric signal without contacting the contacts. Another object of the present invention is to provide a method for determining the driving key of a keyboard having a simple structure for generating an electric signal without bringing the contacts into contact with each other.

[0011]

To achieve this object, in the present invention, a frequency-shifted optical beam is divided into two optical beams (reference light and reflected signal light), and these are divided. Frequency-shifted optical heterodyne detection is performed to generate a beat signal, and the key that generated the reflected signal light, that is, the driving key is discriminated from the beat frequency.

Instead of the beat frequency, the phase difference of the amplitude-modulated signal light caused by the time shift due to the optical path difference between the amplitude-modulated reference light and the reflected signal light is detected, and the driving key is discriminated from this phase difference. May be.

The reflected signal light may be totally reflected, or the transmitted light beam may be blocked by a shutter so that the reflected signal light thereafter may be extinguished.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

As shown in FIGS. 1 and 2, a light source 12 is provided in a key board driving key discriminating apparatus 10 according to the present invention.
A key reflection plate 14 capable of reflecting the light beam from the light source is provided so as to be able to move up and down integrally with the key 16, and the light beam from the light source is reflected in a predetermined direction by driving the key. Is configured.

The keyboard 11 is generally a personal computer (personal computer), word processor (word processor).
As shown in FIG. 3, a large number of keys 16 for inputting various commands to the main body of a personal computer, etc. are arranged on the keyboard board 18 substantially regularly over several stages. Are aligned. As shown in FIG. 2, the key 16 is formed, for example, with a support rod 20 at the lower end, and the key is inserted into the insertion hole 22 by loosely inserting the support rod into the key board base 18. Installed.

For example, a key is provided by a return spring 24 wound around a support rod 20 above the keyboard base 18.
16 is biased upward, and a key 26 is prevented from being disengaged upward by a stopper 26 provided on a support rod below the keyboard board.

As the return spring 24, for example, a compression coil spring is used. However, the return spring 24 is not limited to the compression coil spring, and the return spring may be formed of, for example, a torsion spring or a leaf spring.

As described above, the key 16 is constructed so that it can be driven (pushed) from above against the biasing force of the return spring 24, and the operator can drive the key as desired.
The keyboard 11 is operated and various information is input to the body of a personal computer or the like. And after hitting key-16, key
Excluding the operating force to the key, the key is biased upward under the biasing force of the return spring 24 and automatically returns to the initial position.

The key 16 is not limited to the structure shown in the figure, as long as it can be driven into the key board base 18. Here, the configuration of the key itself is publicly known, and since the configuration itself is not the gist of the present invention, its detailed description is omitted.

A key reflection plate 14 is fixed to the lower end of the support rod 20 and is configured to be movable up and down integrally with the key 16.
As can be seen from FIGS. 2 and 4, the key reflector 14 is formed, for example, by aluminum vapor deposition on the surface of one side of the base portion 14a fixed to the lower end of the support rod 20. The key reflector 14 is arranged on the light source side so as to reflect the light beam 28 from the light source 12 (see FIG. 2).

As shown in FIG. 1, as the light source 12, for example, a unidirectional light beam (laser beam) 28 can be irradiated in the key arrangement portion, that is, in the key row direction. A semiconductor laser oscillator is used. The output of the semiconductor laser oscillator (light source) 12 is preferably 2 mW or more.

The semiconductor laser oscillator (light source) 12 is connected to a waveform oscillator 32 via a current modulation power source 30, for example.
Thereby, the frequency-shifted optical beam 28 can be irradiated.

Optical beam 28 from semiconductor laser oscillator 12
Is irradiated onto the lens system 36 through the optical isolator 34,
The light is focused by a lens system and propagated and irradiated in the key arrangement portion (key row) direction.

In the present invention, the optical beam 28 from the semiconductor laser oscillator 12 is divided into two, one of which is the reference light (reference light) and the other of which is the reflected signal light reflected by the key reflector, and the reference light is used. light,
The reflected No. 4 light is subjected to frequency shift optical heterodyne detection to generate a beat signal, and the key input from the beat frequency is discriminated.

As shown in FIG. 1, the dividing means 38 is composed of a half mirror, and the half mirror is, for example, a pair of superposed surfaces of two prisms 38a and 38b superposed with a thin film. Is a semi-transparent reflection surface that reflects, transmits, and divides the light beam 28. The half mirror 38, which is a combination of the two prisms 38a and 38b, is usually called a half mirror tube. The half mirror may be formed from a semitransparent reflection plate in which a thin film is formed on one surface of thin transparent glass or a plastic plate.

A semiconductor laser oscillator 12 is attached to the half mirror 38.
When the light beam 28 from the above is irradiated, the first beam 28a reflected and the second beam transmitted by the half mirror 38 are transmitted.
The optical beam is divided into the beam 28b, and each optical beam is a prism.
It is propagated and irradiated in each direction via 38a and 38b. In the present invention, since the frequency-shifted optical beam 28 is used, the first beam 28 and the second beam 28b are optical beams.
It can be easily separated from the 28.

Here, aluminum is vapor-deposited on one surface of the prism 38a to form a reflector 42 as a total reflection mirror.
The light is reflected by the reflector in the direction of the half mirror without passing through the beam 28a.

In such a structure, the first beam 28a totally reflected by the reflector 42 is again radiated as the reference light to the half mirror 38 serving as a light receiver. Although it is preferable that the reflector 42 totally reflects the first beam 28a,
It may be partially transparent.

Also, as shown in FIGS. 1 and 2, the second beam 28b divided by the harmylar 38 is formed only by the key reflector 14 (14-4) of the key which is driven in. Key to be reflected
It is irradiated in the row direction (left in the figure). Then, the second beam reflected by the key reflector 14 (14-4) of the key that was driven in.
The beam 28b is again irradiated as reflected signal light to, for example, the half mirror 38 serving as a light receiving body.

Here, when the reference light 28a and the reflected signal light 38b reflected and reflected by the half mirror 38 are interfered by the half mirror, the reference light (first beam) and the reflected signal light (first beam). Two
The interference signal light 40 is generated due to the difference in the irradiation distance of the beam.

The interference signal light 40 generated by the half mirror 38 is focused by a lens system 44, for example, as shown in FIG. 1, and the beat frequency is detected by the light detecting means 46.

As the photodetecting means 46, for example, a square-law detection photodetector capable of optical heterodyne detection is used. Then, the light detection means 46, for example, via the amplifier 48,
It is connected to the output means 50 and outputs an electric signal corresponding to the beat frequency.

The output means 50 is, for example, an interference signal light which is different for each key generated and detected by driving the key 16.
It is a multi-stage bandpass filter whose center frequency is 40 beat frequencies. Then, the implantation key is determined by the presence or absence of an electric signal generated by turning on / off the corresponding bandpass filter.

The output means 50 need only output an electric signal in accordance with the detected beat frequency, and is not limited to a bandpass filter. For example, the output means may be composed of a scanning filter.

For example, a beam by optical heterodyne detection
The frequency f is calculated by f = 4ΔL · δν · fm / c.

In the above mathematical expression, f is the beat frequency, ΔL is the difference in the irradiation distance between the reference light and the reflected signal light (optical path difference), δν is the frequency shift amount, and fm is the frequency shift repetition frequency, c is the speed of light.

Here, for example, δν = 30 GHz, fm = 500H
z = ΔL = 20mm, 500mm, 1000m
For m, f = 4KHz, 100KHz, 200KHz.

That is, when the minimum key interval is 20 mm, if the bandpass filter of the output means 50 is formed every 4 KHz, it is possible to output an electric signal corresponding to the driving key.

Since the minimum distance resolution δL in this configuration is determined by δL = c / 4δν, when δν = 30GH, δL = 2.5 mm.

As shown in FIG. 1, the half mirror 38 becomes the reference point L0, and from the reference point L0 the key positions L1 to
The interference signal light 40 corresponding to the distance to Ln is generated from the superposition of the reference light 28a and the reflected signal light 28b.

That is, as shown in FIGS. 1 and 2, the key 16
By pressing (16-4), the corresponding key reflector 14 (14-
When (4) descends and enters the optical path of the second beam 28b, the second beam is reflected by the key reflector 14-4. Then, the reflected signal light (second beam) 28b is irradiated on the half mirror 38 again with a time lag corresponding to the distance from the reference point L0 to the key position L4.

Then, the reference beam (first beam) 28a and the reflected signal beam (second beam) 28b are interfered by the half mirror 38 to generate an interference signal beam 40, and the beam is detected by the photodetector 46. -The frequency is detected, the corresponding electric signal is output by the output means 50, and the driven key is determined.

As described above, according to the key board driving key discriminating method of the present invention, the reflected signal light 28a and the reference light 28a reflected by the key reflector 14 of the driven key are detected. The interference signal light 40 is generated, and the driving key is discriminated from the beat frequency. That is, in contrast to the known configuration in which the key driving is converted into an electric signal by the contact of the pair of contacts, the driving key determining method of the present invention is a non-contact type in which the contacts are not contacted. .

Therefore, contact failure due to contact deformation, deterioration, etc. can be prevented, erroneous input (malfunction) caused by contact failure can be reliably prevented, and operability of the keyboard 11 is improved.

Further, since there is no contact, the semiconductor laser oscillator 12
Since it is sufficient to reflect and receive the light beam 28 from the
The method of the present invention can be particularly effectively utilized as a method for determining the so-called alpha-numeric key type key for frequently used English characters, numbers, symbols, etc. without being affected by the frequency of use.

In contrast to the known structure in which the key 16 is driven to the lowermost position to bring the pair of contacts into contact with each other, according to the present invention, the key reflector is moved to the position where the second beam 28b is reflected.
Since it suffices to lower 14, the driving key can be detected and determined without being affected by the driving force of the key, that is, the operating force. Therefore, the keyboard with a light touch
Operation becomes possible.

The key reflector 14 has only to reflect the second beam 28b back to the half mirror 38 so that it can be reflected by the support rod.
The machining tolerance and the assembly tolerance of the key 16, the key reflector, etc. in the axial direction of 20 can be made relatively large.

Furthermore, a key that can be raised and lowered integrally with the key 16
The reflector 14 may be provided, and the semiconductor laser oscillator 12, the half mirror 38, etc. may be provided at positions corresponding to the key rows. Therefore, the keyboard 11 and the optical system can be integrally arranged in a plane, and the configuration is simplified. Therefore, the workability at the time of assembly is high, and the overall cost reduction of the keyboard 11 can be expected sufficiently. Further, due to the simplification of the configuration, breakdowns are reduced and maintenance can be easily performed.

Further, it is not necessary to use transparent plastic or the like as a transmission medium for the optical beam or to disperse the optical beam, so that the structure can be simplified.

In the present invention, since the frequency-shifted optical heterodyne detection is performed, the driven key can be surely and quickly discriminated by the output means 50 such as a multistage bandpass filter or a scanning filter.

According to the key board driving key discriminating apparatus 10, the above-mentioned driving key discriminating method can be properly executed in spite of its simple structure.

It is preferable that a total reflection member is provided at the end of the optical path, and the signal frequency is constantly reflected to be used for monitoring the optical path because an abnormality can be easily detected.

In the embodiment, the Hafmirra 38 is used as the reference beam 28.
Since it also serves as a light receiving body for receiving the reflected signal light 28b, the structure can be further simplified. However, Hafmirah
The reference light and the reflected signal light may be received by a light receiver separate from 38.

Further, since the harmylar 38 is formed from the harmylar cube, the light beam 28 can be appropriately divided and a reflector for reflecting the first beam 28a.
42 can be easily formed by aluminum vapor deposition on one surface of the prism 38a, and a half mirror having a simple structure can be obtained. However, the half mirror 38 may be formed from a member other than the prism.

Further, in the embodiment, the key reflector 14 is
Although it is formed of a flat mirror surface, it is not limited to this and may be, for example, a concave mirror surface as shown in FIG. With such a concave reflecting mirror surface, the second beam 28b dispersed due to the vertical movement of the key reflector or long-distance irradiation is focused and folded back to the half mirror 38. Since the irradiation is performed, it is possible to sufficiently prevent the decrease in the intensity of the light beam.

Therefore, high precision is not required for molding the key reflector 14 or mounting the key itself, and the workability during assembly is improved. The concave mirror-finished key reflector 14 can be used particularly effectively in the configuration in which the distance between the half mirror 38 and the half mirror 16 is long.

The key reflector 14 is embodied as a mirror surface of which aluminum is vapor-deposited on the surface of the base, but it should be capable of reflecting the light beam, that is, the second beam 28b in the half mirror direction. It is sufficient, but not limited to this. For example, a right angle prism (see FIG. 6) or a corner cube prism (see FIG. 7) is fixed to the lower end of the supporting rod 20 of the key, and the second beam 28b is reflected by these prisms. Good.

The corner-curve prism is used as a key reflector 14.
In the above configuration, even if the light receiving surface of the corner-curve prism moves vertically or horizontally, the second light is received.
The beam 28b is reliably reflected and reflected in the direction of the half mirror. Therefore, the strength of the optical beam 28b can be surely prevented from being lowered, and the accuracy of molding the key reflector and mounting the key itself can be eased.

In the embodiment, as shown in FIG. 1, the driving key discriminating apparatus 10 has a structure in which one horizontal row of keys is one block and the driving key is discriminated for each block.
Is illustrated. However, the configuration is not limited to this, and the optical beam 28 from the semiconductor laser oscillator 12 may be shared by the multi-stage key row 56.

For example, as shown in FIG.
The optical beam 28 from the oscillator 12 is connected to the multi-stage key row 56 (56-1 ~
All the key reflectors in (56-3) can be continuously illuminated,
The rows 56 may be arranged.

In FIG. 8, the second beam from the harf mirror 38 is shown.
The corner reflector 58 (5
8-1 to 58-5) are arranged in the respective corners of the multi-stage key row 56 (56-1 to 56-3), and the second beam 28b is connected to the next row of key rows. It propagates and irradiates in the direction.

When the optical beam 28 from the semiconductor laser oscillator 12 is divided into two by the half mirror 38, the half mirror 38
The second beam 28b that has passed through is transmitted straight to the key row 56-1 in the same row and is propagated and irradiated. Then, the second beam 28b passing through the key row 56-1 is reflected by the corner reflectors 58-1 and 58-2 and propagates to the next key row 58-2, Is irradiated. Similarly, the second beam 28b passing through the key row 56-2 is
Key rows 56-3 adjacent to each other via corner reflectors 58-3 and 58-4
Is reflected on the final corner reflector 58-5.

In this structure, the second beam 28b is continuously propagated and irradiated to all the key rows in a substantially S-shaped one-stroke writing pattern. Then key 16 is typed in arbitrarily and the corresponding key
When the reflector 14 descends, the second beam 28b is reflected by the key reflector, travels in the direction opposite to the propagation from the half mirror 38, and irradiates the half mirror again as reflected signal light. To be done.

Therefore, it is possible to irradiate the second beam 28b to the key row 56 (56-1 to 56-3) without providing the semiconductor laser oscillator 12 for each key row, and The points are reduced,
The driving key discrimination device 10 can be structurally further simplified.

Further, instead of continuously irradiating in a single-stroke form, as shown in FIG. 9, the optical beam 28 from the semiconductor laser oscillator 12 is branched so as to be divided into each multi-stage key row. It may be propagated or irradiated.

For example, the branching means 60 (60-1, 60-2) and the reflecting means 61 are arranged in a multi-stage key row 56 (56-1 to 56-3), and the reflecting means 61 is the final key. -To the corner of the row 56-3, the branching means 60 is arranged in the same row as the half mirror 38 in the corners of the key rows (56-1, 56-2) excluding the final key row. It is provided in. For example, the branching means is a semitransparent reflecting surface (Half-Miller-Cube) capable of reflecting and transmitting the light beam, and the reflecting means 61 is a total reflection surface for reflecting the light beam. .

Therefore, when the optical beam 28 from the semiconductor laser oscillator 12 is split into two by the half mirror (splitting means) 38, the second beam 28b transmitted through the half mirror is First,
In the branching means 60-1, the direction of the key row 56-1 and the branching means 60-2 in the next stage
Direction and branched into. The second beam 28b emitted to the branching means 60-2 is reflected by the reflecting means 61 in the direction of the key row 56-2.
The second direction, which is further branched to
Beams illuminate key row 56-3.

Then, the second beam 28b irradiated on the key rows 56-1 to 56-3 is reflected by the key reflector 14 of the driven key 16 and travels in the opposite direction to give a reflected signal. The half mirror is irradiated again as light.

Also in this configuration, the irradiation of the second beam 28b for each key column can be obtained without providing the semiconductor laser oscillator 12 for each key column, and the configuration can be simplified.

In this configuration, the branching means 60 (60-1, 60-1,
60-2) and the reflection means 61 are arranged, the irradiation distance of the second beam 28b for each key row is suppressed, and the key reflector 14 is provided.
The reduction of the intensity of the reflected signal light due to the blurring of the second beam 28b and the dispersion of the second beam 28b is prevented.

The branching means 60 (60-1, 60-2) and the reflecting means 61 cause the second beam 28b to be optically beamed to the key row 56 (56-1 to 56-3).
However, the present invention is not limited to this, and for example, the semi-transparent reflection plate and the total reflection plate may be combined to form the key board driving key determination device 10.

In the embodiment, the key row 56 has three stages, but needless to say, it is not limited to three stages.

In the embodiment, the key reflector 14 is exemplified as a structure for totally reflecting the second beam 28b.
The present invention is not limited to this, and, for example, partially transmitting the second
The beam may be blocked by a shutter.

For example, in a keyboard key deciding device 10-2 of another embodiment of the present invention shown in FIG. 10, a shutter 62 is integrally provided on a key 16 via a supporting rod 20. In addition, the key reflectors 64 are arranged between the adjacent keys.

The key reflector 64 is, for example, a reflector capable of transmitting and reflecting the light beam, that is, the second beam 28b, and is fixed to the fixed plate 66 of the keyboard 11. Has been done.
Then, the second beam divided by the half mirror 38
28b is a reflector on the half mirror side (right side in the figure) 64-1
The second beam can be blocked by descending the shutter 62 as the key 16 is driven.

When the shutter 62 is not descending, the second
The beam 28 is reflected by all the reflection plates 62, the respective reflected signal lights are applied to the half mirror 38, and the beat frequencies corresponding to the respective reflected signal lights are detected. Then, when the key 16 is driven and the corresponding shutter 62-3 descends to the optical path of the second beam 28b, the second beam is released.
The reflected signal lights from the key reflectors 64-4 and 64-5 located on the left side of the shutter 62-3 in the figure are blocked by the shutter 62-3, respectively.

That is, in this configuration, the disappearance of the interference signal light 40 corresponding to the reflected signal light from the reflection plates 64-4 and 64-5 in the photodetector 46 and the output means 50 is detected and injected. The key is determined.

According to the key board driving key discriminating apparatus 10-2 of this construction, the key reflector 6 having the second beam 28b fixed thereto.
Since the light is reflected at 4, the key reflection plate is not shaken, and the reflected reflection of the reflected signal light to the half mirror 38 can be reliably obtained.

Further, the shutter 62 only needs to block the second beam 28b, and the shutter itself is not required to have high accuracy.

In each of the above embodiments, the first beam 28a and the second beam 28b divided by the harmylar 38 are harbored.
The humming mirror is used for interference, and the driving key can be discriminated from the beat frequency generated by the interference. However, regardless of the beat frequency, the driving key can be discriminated from the phase difference caused by the optical path difference between the first beam and the second beam.

As shown in FIG. 11, in the key board driving key discriminating apparatus 110, the first beam 28a and the second beam 28b are capable of detecting the phases of the amplitude modulation signals respectively. First and second photodetectors 68 and 70 are provided.

For example, the waveform oscillator 32 is the amplitude modulation power supply 13
The optical beam 28, which is connected to the semiconductor laser oscillator 12 via 0 and is obtained by modulating the semiconductor laser with a sine wave signal of about 1 MHz, uses a half mirror 38 as a reference beam 28a and a reflected signal. Light 28b
When divided into, the output Ir of the reference light detected by the photodetector 68 is obtained from the following equation, where the modulation frequency of the semiconductor laser is fm. Ir = I · sin (2πfm · t)

On the other hand, the phase of the reflected signal light 28b is
As shown in FIG. 12, if the photodetectors 68, 70 are equidistant from the half mirror 38 by delaying by an amount equivalent to the optical path difference (2Ln), the output In of the reflected signal light 28b at the photodetector 70 is as follows. (C: speed of light). In = I · sin (2πfm (t-2Ln / c)

Therefore, the phase difference φ obtained by comparing the phases of the reference light 28a and the reflected signal light 28b, and the distance Ln obtained therefrom are as follows. φ = 2πfm (2Ln / c) Ln = φ · c / 4πfm In this way, if the phase difference φ between the amplitude-modulated lights of the reference light 28a and the reflected signal light 28b is detected, the distance Ln can be obtained and the key entered − Is determined.

In the embodiment, the first and second photodetectors 68, 70
The phases of the amplitude-modulated lights of the reference light 28a and the reflected signal light 28b detected in 1 are compared by the phase comparator 72 connected to each photodetector. The phase comparator 72 has, for example, a well-known configuration shown in FIG. 13, outputs a voltage value corresponding to the phase difference between the amplitude modulated lights of the reference light 28a and the reflected signal light 28b, and outputs the voltage connected to the phase comparator. An electric signal corresponding to the voltage value is output by the means 74 and the driven key 14 is discriminated.

As described above, the driving key can be discriminated by detecting the phase difference between the amplitude-modulated reference light 28a and the reflected signal light 28b. Also in this configuration, the same effect as that of the above embodiment by the beat frequency can be obtained. can get.

FIG. 14 shows another embodiment. In this example,
Instead of outputting the reference light, the phase is compared with the modulation signal from the waveform oscillator 32 or the amplitude modulation power supply 130,
The driving key is determined in the same manner as in the above embodiment. This configuration has the advantage that one photodetector is sufficient and the number of parts can be reduced.

In the embodiment shown in FIG. 15, the linearly polarized light beam 28 (optical field vector is parallel to the paper surface) output from the semiconductor laser oscillator 12 is a polarization beam splitter 75 on the optical path. The circularly polarized light passes through the quarter corrugated plate 76 and is reflected by the reflector 14. The reflected circularly polarized light beam
Returning to the quarter corrugated plate 76, it becomes a linearly polarized light which is perpendicular to the paper surface, and the linearly polarized light is a polarized beam splitter which is a light receiving body.
It becomes reflected signal light 28b which is reflected without going straight through 75 and is incident on the photodetector 68.

In this embodiment, no light returns to the semiconductor laser oscillator 12. Further, the reflected signal light 28b can be received by the photodetector 68 without being lost by the half mirror.

In the embodiments shown in FIGS. 14 and 15, only the second beam is used without the need for the first beam, and in other embodiments, these embodiments are also used. The technical idea of can be applied.

It goes without saying that the semiconductor laser oscillator also includes an oscillator using a light emitting diode or a super luminescent diode having a high light beam brightness and good light-collecting property. Nor.

The method and apparatus for discriminating the driving key of the keyboard according to the present invention are suitable for the keyboards of personal computers, word processors, etc., but are not limited thereto. Instead, it can be applied to a keyboard for musical instruments such as an electronic piano, an electon, and a synthesizer.

The above-mentioned embodiments are for explaining the present invention, and do not limit the present invention in any way.
It goes without saying that the present invention includes all those which are modified or modified within the technical scope of the present invention.

[0095]

As described above, the keyboard according to the present invention is used.
According to the method of discriminating the driving of the contact, the contact is made non-contact without contact, contact failure due to contact deformation, deterioration, etc. can be prevented, and erroneous input caused by contact failure can be reliably prevented.

Whether the entered key is determined from the beat frequency or the phase difference can be structurally simplified, and the key board driving key determination method is as follows. This can be performed by a key board driving key discriminating device having a simple structure.

Since the frequency-shifted optical beam is used, the first beam and the second beam can be easily separated from the optical beam.

Frequency shift optical heterodyne detection,
The beat frequency depends on the distance to the key reflector and the frequency shift amount of the semiconductor laser, and the base band frequency can be arbitrarily selected and designed.

By means of the corner reflectors arranged in the respective corners of the key row, the light beam (second beam) is continuously applied to all the keys in a one-stroke form. If it is possible to irradiate each key row, it is possible to irradiate each key row with an optical beam without providing a laser oscillator or the like.

If the second beam is branched for each key row by the branching means provided in the corner, the irradiation distance of the optical beam for each key row is sufficiently suppressed and the key reflection is performed. It is possible to sufficiently prevent the decrease in the intensity of the reflected signal light due to the blurring of the body or the dispersion of the light beam.

Further, instead of totally reflecting by the key reflector which is integral with the key, the reflected signal light from the key reflector which is fixed between the adjacent keys and which can transmit the second beam is transmitted. Even if the shutter is shut down by lowering the shutter as the key is driven, the driven key can be identified.

If the reflecting plate is formed of a corner-curve prism, even if the light-receiving surface of the corner-curve prism is vertically or horizontally deviated, the second beam that has received the light will be reflected. -Because it is reliably reflected and reflected in the direction of Fumira,
The decrease in the intensity of the light beam can be prevented more reliably.

Further, the harf mirror is used as a dividing means, and
If the mullar mirror is a half mirror cuvette, the light beam can be appropriately divided, and a reflector for reflecting the first beam can be easily formed by vapor-depositing aluminum on one surface of the prism. , The configuration can be simplified.

If the half mirror also serves as a light receiving body, an increase in the number of parts can be prevented and the structure can be further simplified.

Further, if the key reflecting plate is made concave, the light beams dispersed by the blurring of the key reflecting plate and the irradiation of a long distance are focused, so that the intensity of the light beam is lowered. Can be fully prevented.

If the key reflector is a corner-curve prism, even if the light receiving surface is vertically or horizontally deviated, the received second beam is reliably reflected and reflected, and the intensity of the optical beam is reduced. Can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a key board driving key determining device according to the present invention.

FIG. 2 is a partial vertical cross-sectional view of a key of the key board driving key determining device.

FIG. 3 is a schematic perspective view of a keyboard.

FIG. 4 is a schematic perspective view of a key reflector.

FIG. 5 is a modification of the key reflector.

FIG. 6 is a modification of the key reflector.

FIG. 7 is a modification of the key reflector.

FIG. 8 is a schematic layout diagram of a key row in which a second beam is continuously irradiated in a one-stroke writing pattern.

FIG. 9: Keys in which a second beam is irradiated in parallel for each key row
It is a schematic layout drawing of a row.

FIG. 10 is a key of a key board driving key discriminating device according to a modification of the present invention, which can be shut off by a shutter.
FIG.

FIG. 11 is a schematic block diagram of a key board driving key discriminating apparatus in another embodiment of the present invention for discriminating a driving key from a phase difference.

FIG. 12 is a diagram showing a phase difference between outputs of reference light and reflected signal light.

FIG. 13 is a block diagram of a phase comparator.

FIG. 14 is a schematic block diagram of a keyboard key driving key determining device for determining a driving key based on a phase difference in another embodiment of the present invention.

FIG. 15 is a schematic block diagram of a key board driving key judging device for judging a driving key based on a phase difference in another embodiment of the present invention.

[Explanation of symbols]

 10, 110 Key board driving key discrimination device 11 Key board 12 Light source (semiconductor laser oscillator) 14 Key reflector 16 key 28 Optical beam (laser beam) 28a First beam (reference light) 28b Second beam (reflected signal light) 30 Current modulation power supply 32 Waveform oscillator 38 Dividing means (Half mirror) 46 Optical detecting means 50 Output means (Multi-stage bandpass filter) ) 58 Corner reflector 60 Branching means 61 Reflecting means 62 Shutter-64 Key reflecting plate 68 First photodetector 70 Second photodetector 72 Phase comparator 74 Output means 130 Amplitude modulation power supply

Claims (25)

[Claims] 1. A method for determining a key board driven key in which a key driving is converted into an electric signal and the key driven is discriminated from the electric signal. The beam is divided into a first beam and a second beam, the first beam is reflected to serve as a reference beam, and the second beam is propagated and irradiated in the direction of the arrangement of the keys to form a key.
The reflected light is reflected by a reflector to generate reflected signal light, and the reference light and reflected signal light are frequency-shifted by optical heterodyne detection to generate a beat signal. A method for discriminating a key board driving key, characterized by discriminating. 2. A key board driving key discrimination method for converting a key driving to an electric signal and discriminating a driven key from the electric signal, wherein an amplitude-modulated optical beam is used as a second signal. The beam is divided into a first beam and a second beam, the first beam is reflected to serve as a reference beam, and the second beam is propagated and irradiated in the direction of the arrangement of the keys to form a key.
The reflected light is reflected by a reflector to compare the phases of the reference light and the reflected signal light, and the driven key is discriminated from the output corresponding to the phase difference. Driving key identification method. 3. A key board driving key discrimination method for converting a key driving to an electric signal and discriminating the driven key from the electric signal, wherein an amplitude-modulated optical beam is scanned. -Propagate and irradiate in the array direction, and reflect it with a key reflector as reflected signal light.Compare the phases of the amplitude-modulated electric signal and the electric signal of the reflected signal light, and input from the output corresponding to the phase difference. A key board driving key discrimination method, which is characterized by discriminating a stored key. 4. A second beam is continuously applied to the key reflectors of all the keys in a one-stroke form via the corner reflectors of the key rows arranged in multiple stages. The method for discriminating a key board driven key according to claim 1, wherein the irradiation is performed. 5. A key board driving key discrimination according to any one of claims 1 to 4, wherein the second beam is branched and radiated in parallel to the key rows arranged in multiple stages. Method. 6. The method of discriminating a key board driving key according to any one of claims 1 to 5, wherein the second beam is totally reflected by the key reflecting plate of the key pressed. 7. The second beam which is reflected by the key reflector between the keys to be reflected signal light and which is transmitted through the key reflector and transmitted through the key reflector. 7. The keyboard according to any one of claims 1 to 6, wherein the shutter of the key that is driven in is used to block the reflected signal light after the key.
How to determine the key to drive the key. 8. A semiconductor laser oscillator for irradiating a frequency-shifted optical beam, and an optical beam from the semiconductor laser oscillator is divided into a first beam and a second beam, The dividing means for propagating each light beam in a specific direction, the reflector for reflecting the first beam and irradiating the light receiver as a reference light, and the key are provided integrally with the key. Second, due to the
As the beam descends into the optical path, it reflects the second beam,
A frequency-shiftable heterodyne-detectable light that detects a beat frequency from a key reflector that illuminates a photoreceptor to generate reflected signal light and the interference signal light between the reference light and the reflected signal light that are superimposed and interfered by the photoreceptor The detection means and the output means for processing the input signal from the light detection means and outputting the electric signal corresponding to the beat frequency are provided, and the driven key is discriminated from the electric signal from the output means. A key board driving key discriminating device. 9. A semiconductor laser oscillator for irradiating an amplitude-modulated optical beam, and an optical beam from the semiconductor laser oscillator for a first beam and a second beam.
Splitting means for splitting the light beam into each beam and propagating each light beam in a specific direction, a reflector for reflecting the first beam and irradiating it as a reference light to a light receiving body, and between adjacent keys. And a key reflector which is respectively disposed in the optical path of the second beam, transmits and reflects the second beam, and irradiates the reflected second beam as a reflected signal light to the light receiver, and a key. The second, which is provided integrally with the
The beat frequency is detected from the interference signal light of the reference light and the reflected signal light which are overlapped by the light receiver and interfered by the reflected signal light after the key when the beam descends to the optical path. And a means for processing an input signal from the light detecting means to output an electric signal corresponding to the beat frequency, the electric signal from the output means , A key board driving key discriminating device for discriminating the driven key. 10. A semiconductor laser oscillator for irradiating an amplitude-modulated optical beam, and an optical beam from the semiconductor laser oscillator for a first beam and a second beam.
A dividing means for dividing the beam into beams and propagating each of the optical beams in a specific direction, a reflector for reflecting the first beam and irradiating the photoreceptor as a reference beam, and a key. Second, which is provided in the
As the beam descends into the optical path, it reflects the second beam,
A key reflector for irradiating a photoreceptor as reflected signal light, first and second photodetectors for detecting reference light and amplitude-modulated light of reflected signal light, respectively, and a first and second photodetector. A phase comparator that compares the phases of the amplitude-modulated signals of the detected reference light and reflected signal light, and output means that outputs an electrical signal corresponding to the phase difference detected by the phase comparator, are provided. A key board driving key discriminating device for discriminating a driven key from an electric signal. 11. A semiconductor laser oscillator for irradiating an amplitude-modulated optical beam, and an optical beam from the semiconductor laser oscillator for a first beam and a second beam.
Splitting means for splitting the light beam into each beam and propagating each light beam in a specific direction, a reflector for reflecting the first beam and irradiating it as a reference light to a light receiving body, and between adjacent keys. And a key reflector which is respectively disposed in the optical path of the second beam, transmits and reflects the second beam, and irradiates the reflected second beam as a reflected signal light to the light receiver, and a key. The second, which is provided integrally with the
A shutter that blocks the reflected signal light after the key by the descending of the beam to the optical path, first and second photodetectors that respectively detect the reference light and the amplitude-modulated light of the reflected signal light, A phase comparator for comparing the amplitude modulation signals of the reference light and the reflected signal light detected by the first and second photodetectors, and output means for outputting an electric signal corresponding to the phase difference detected by the phase comparator, And a key board driving key discriminating apparatus for discriminating the driven key from the electric signal from the output means. 12. A semiconductor laser oscillator for irradiating an optical beam amplitude-modulated by an amplitude-modulating power supply, a semiconductor laser oscillator, a half mirror arranged in an optical path between the keys, and a key. And a key reflector that reflects the light beam as it descends to the optical path when the key is driven, and is reflected by the half mirror as reflected signal light to irradiate the photoreceptor. A photodetector that detects the amplitude-modulated light of the signal light, a phase comparator that compares the phases of the modulated electrical signal from the amplitude-modulated power supply and the modulated electrical signal from the photodetector, and the phase difference detected by the phase comparator. And an output means for outputting an electric signal corresponding to the above, and a key board driving key discriminating apparatus for discriminating a driven key from the electric signal from the output means. 13. A semiconductor laser oscillator for irradiating an optical beam amplitude-modulated by an amplitude-modulating power source, a semiconductor laser oscillator, and a half mirror arranged in an optical path between the keys are adjacent to each other. Key reflectors which are respectively arranged in the optical path between the keys to transmit and reflect the light beam, and the reflected light beam is reflected by the half mirror as reflected signal light to irradiate the light receiver, A shutter that is also provided integrally with the key and that shuts off the reflected signal light after the key when the key is driven down into the optical path, and a photodetector that detects the amplitude-modulated light of the reflected signal light. A phase comparator for comparing the phases of the modulated electric signal from the amplitude modulation power source and the modulated electric signal from the photodetector, and an output means for outputting an electric signal corresponding to the phase difference detected by the phase comparator, Equipped with, from the electrical signal from the output means, Key - to determine the key - board - de implantation key - discriminating device. 14. A semiconductor laser oscillator for irradiating a linearly polarized light beam amplitude-modulated by an amplitude modulation power source, and a polarization beam arranged in the optical path between the semiconductor laser oscillator and the key.
Optical beam which is provided integrally with the key splitter and the quarter wavelength plate disposed in the optical path between the key splitter and the variable beam splitter. Of the reflected signal light, which reflects the optical beam as it descends to the optical path of the reflected beam, passes through the quarter-wave plate as reflected signal light and is reflected by the polarizing beam splitter to irradiate the photoreceptor. Corresponds to the photodetector that detects the amplitude-modulated light, the phase comparator that compares the phase of the modulated electrical signal from the amplitude-modulated power supply with the phase of the modulated electrical signal from the photodetector, and the phase difference detected by the phase comparator. An input key discriminating device for a keyboard, which comprises an output means for outputting an electric signal, and discriminates a driven key from an electric signal from the output means. 15. A semiconductor laser oscillator for irradiating a linearly polarized light beam amplitude-modulated by an amplitude-modulating power source, and a polarization beam arranged in the optical path between the semiconductor laser oscillator and the key.
1/4 wavelength plate disposed in the optical path between the beam splitter and the key / polarization beam splitter, and in the optical path between the adjacent keys, respectively transmitting and reflecting the optical beam. And a key reflector for reflecting the reflected light beam as a reflected signal light through a quarter-wave plate through a quarter-wave plate and irradiating the photoreceptor with the key, and is also provided integrally with the key. , A shutter that blocks the reflected signal light after the key due to the descent to the optical path due to the input of the key, a photodetector that detects the amplitude modulated light of the reflected signal light, and a semiconductor laser oscillator. A phase comparator for comparing the phases of the modulated electric signal and the modulated electric signal from the photodetector, and an output means for outputting an electric signal corresponding to the phase difference detected by the phase comparator are provided. Of the keyboard that identifies the key that was driven in from the electrical signal of Driving key discrimination device. 16. The keyboard according to claim 8 or 9, wherein the semiconductor laser oscillator irradiates an optical beam whose amplitude is modulated under current modulation, and the dividing means is a half mirror. Drive key discrimination device. 17. A keyboard according to claim 10 or 11, wherein the semiconductor laser oscillator irradiates an optical beam whose amplitude is modulated under current modulation, and the dividing means is a half mirror. Drive key discrimination device. 18. A semiconductor laser oscillator irradiates a frequency-shifted optical beam under current modulation, and the dividing means is a hum mirror, and the hum mirah emits the optical beam. The keyboard according to claim 8 or 9, which is formed by combining prisms so as to be dispersible in a specific direction, and wherein the reflector for reflecting the first beam is formed by aluminum vapor deposition on one surface of the prism.
A device for driving key input. 19. The driving key discriminating apparatus for a keyboard according to claim 18, wherein the half mirror also serves as a light receiving body for the reference light and the reflected signal light. 20. The output means is formed of a multi-stage bandpass filter having a center frequency of each beat frequency generated and detected by key input, and is input depending on the presence or absence of an output signal from each filter. 20. The key board driving key discriminating device according to claim 18, wherein the key is discriminated. 21. The phase comparator outputs a voltage value corresponding to the phase difference between the amplitude modulation signals of the reference light and the reflected signal light, and the output means outputs an electric signal corresponding to the voltage value. 15. The key board driving key discriminating apparatus according to any one of items 1 to 15. 22. An optical beam is provided to each corner of the multi-stage key row.
A corner reflector that totally reflects the beams in the key row direction is provided, and all the key rows are continuously illuminated in a single stroke through the corner reflectors of each key row. 22. The key board driving key discriminating device according to claim 8, wherein the beam is irradiated. 23. An optical beam is provided to each corner of the multi-stage key row.
A branching means for branching the beam in the key row direction and reflecting it and transmitting it in the next key row direction is provided respectively, and an optical beam is applied to the final stage corner of the multi-row key row. 23. A reflecting means for totally reflecting in the key row direction is provided, and an optical beam is irradiated to each key row via the branching means and the reflector means. Key board driving key discriminating device. 24. The key board driving key discriminating apparatus according to claim 8, wherein the key reflecting plate is a concave reflecting mirror surface. 25. The keyboard according to claim 8, wherein the key reflector is a corner-curve prism.
A device for driving key input.