This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-134498, filed Apr. 28, 2004, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an information input apparatus, which enables key input to an information processing apparatus without key touch, and to an information input method of the information input apparatus.
2. Description of the Related Art
In recent years, battery-drivable and portable information processing apparatuses such as notebook type personal computers and PDAs (Personal Digital Assistant) have come into wide use. This kind of information processing apparatus is usable anywhere. Therefore, this serves to greatly improve work efficiency of salespersons, for example.
If this kind of information processing apparatus is used in a train during business transfer, a keyboard is not necessarily usable, unlike indoors. For this reason, information input apparatuses for enabling various inputs in place of the keyboard have been recently researched and developed. An information input apparatus enabling input using hand action exists as one of the forgoing apparatuses (for example, see JPN. PAT. APPLN. KOKAI Publication No. 6-59805).
The information input apparatus disclosed in the foregoing Publication No. 6-59805 detects only two-dimensional coordinates of each finger. For example, considering a keyboard operation, it is determined on which key each finger is placed; however, it is not determined whether or not each finger makes an action depressing a key. In other words, the foregoing apparatus is not suitable to an information input apparatus for the information processing apparatus. The same problem as above arises in handling electronic appliances having several operation buttons without being limited to the keyboard operation of the information input apparatus.
According to an embodiment of the present invention, an information input apparatus comprises: first and second signal sending units attached to right and left end portions of a wrist with a distance therebetween; at least one signal receiving unit, attached to a tip portion of each finger of a hand, configured to receive a signal outputted from the first or second signal sending unit; an acceleration sensors attached to at least one fingertips of fingers attached with the signal receiving unit; a fingertip position detecting unit configured to detect a relative position of a tip portion of each finger attached with the signal receiving unit in a two-dimensional space with its origin at the attached position of either the first or second signal sending unit based on an elapsed time period from a time when the first signal sending unit outputs a signal to a time when each signal receiving unit receives the signal, and an elapsed time period from a time when the second signal sending unit outputs a signal to a time when each signal receiving unit receives the signal; and an action detecting unit configured to detect an action of each finger attached with the acceleration sensor based on acceleration information outputted from each of the acceleration sensors.
According to an another embodiment of the present invention, an information input apparatus comprises: at least one signal sending unit attached to a tip portion of each finger of a hand; first and second signal receiving units, attached to right and left end portions of a wrist with a distance therebetween, configured to receive a signal outputted from the signal sending unit; an acceleration sensors attached to at least one fingertips of fingers attached with the signal sending unit; a fingertip position detecting unit configured to detect a relative position of a tip portion of each finger attached with the signal sending unit in a two-dimensional space with its origin at the attached position of either the first or second signal receiving unit based on an elapsed time period from a time when each signal sending unit outputs a signal to a time when the first signal receiving unit receives the signal, and an elapsed time period from a time when each signal sending unit outputs a signal to a time when the second signal receiving unit receives the signal; and an action detecting unit configured to detect an action of each finger attached with the acceleration sensor based on acceleration information outputted from each of the acceleration sensors.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.
An embodiments of the present will be described below with reference to the accompanying drawings.
A signal processor 10 attached to the wrist controls the entirety of the information input apparatus 1. The signal processor 10 is connected with ultrasonic speakers 11R, 11L, ultrasonic microphones 12a to 12e, and acceleration sensors 13a to 13e. The signal processor 10 is further connected with a correction ultrasonic speaker 14 and correction ultrasonic speaker microphone 15. The ultrasonic speakers 11R and 11L are attached to both end portions of the wrist, respectively. The ultrasonic microphones 12a to 12e and acceleration sensors 13a to 13e are respectively attached to tip portions of five fingers. The correction ultrasonic speaker 14 and correction ultrasonic microphone 15 are respectively attached to both end portions of the palm. In the foregoing end portions of the palm, a change of the relative position from the wrist is small even if a hand action is made.
The method of detecting the fingertip position by the two-dimensional position detecting unit 101 will be described below with reference to
The unit 101 generates an ultrasonic wave from ultrasonic speakers 11R and 11L attached to both end portions of the wrist so that ultrasonic microphones 12a to 12e attached to fingertips detect it. Then, the unit 101 detects a relative position of each fingertip from the wrist based on the principle given below.
First, the unit 101 calculates distances DR and DL of
x2+y2=dR2 (1)
(x−dRL)2+y2=DL2 (2)
Thus, using the foregoing equations (1) and (2), the unit 101 detects the position (x, y) of the ultrasonic microphones 12a to 12e, that is, the relative position of each fingertip from the wrist.
Incidentally, the ultrasonic speakers 11R and 11L generate ultrasonic waves having a frequency different from each other, thus, the ultrasonic microphones 12a to 12e or the two-dimensional position detecting unit 101 may make frequency analysis to determine a signal sending source. The ultrasonic speakers 11R and 11L may generate the ultrasonic wave at regular intervals so that the ultrasonic microphones 12a to 12e or the unit 101 determines the signal sending source.
The method of detecting an action by the action detecting unit 102 will be described below with reference to
The unit 102 detects a predetermined series of changes occurring in acceleration outputted by accel-eration sensors 13a to 13e attached to fingertips, thereby recognizing an action of just like hitting a keyboard. In this case, the acceleration sensors 13a to 13e have sensitivity in the direction vertical to the palm of the hand (x-y plane). The finger position when hitting action by finger produces changes as shown in
(1) Acceleration is less than negative threshold value ATHM (2) Acceleration is more than positive threshold value ATHP (3) Acceleration is less than negative threshold value ATHM Incidentally, a bend angle of a joint may be detected using a bend sensor in order to improve accuracy.
As described above, the two-dimensional position detecting unit 101 detects the fingertip position while the action detecting unit 102 detects the action. Further, the information input apparatus 1 of the embodiment performs an error reduction procedure using the foregoing correction ultrasonic speaker 14 and correction ultrasonic microphone 15.
The unit 101 corrects a position detection error by a two-dimensional change in speed of sound resulting from the hand action, wind, etc. using the foregoing speaker 14 and microphone 15. The distance between the ultrasonic speaker 11R and the microphone 15 and the distance between the microphone 15 and the speaker 14 are approximately constant even if a hand action is made. In addition, the foregoing speaker 11R, microphone 15 and speaker 14 make a right angle. The unit 101 makes an inverse operation with respect to a two-dimensional change in speed of sound resulting from the hand action, wind, etc., and then, corrects it to achieve a reduction in fingertip position detection error. In this case, the foregoing inverse operation and correction are carried out based on two distances predetermined above and ultrasonic wave propagation time from speakers 14 and 11R to the microphone 15.
For example, the whole hand has a velocity (vx, vy) to air resulting from the hand action, wind, etc. As depicted in
(dx−vx tx)2+(vy tx)2=(Vtx)2 (3)
On the other hand, as shown in
(vx tx)2+(dy+vy tx)2=(Vty)2 (4)
The two-dimensional position detecting unit 101 solves the simultaneous equations (3) and (4) to calculate vx and vy. Then, the unit 101 applies correction based on the calculated vx and vy to the fingertip position detecting method described referring to
The operation procedures of the foregoing units 101 and 102 included in the information input apparatus 1 will be described below with reference to
The unit 101 performs the procedure so that the ultrasonic speaker 11R outputs an ultrasonic wave (step A1), and the ultrasonic microphones 12a to 12e detect the ultrasonic wave (step A2). The unit 101 measures the time difference (lag) from the output to detection of the ultrasonic wave (step A3).
Then, unit 101 performs the procedure so that the ultrasonic speaker 11L outputs an ultrasonic wave (step A4), and the ultrasonic microphones 12a to 12e detect the ultrasonic wave (step A5). The unit 101 measures the time difference from the output to detection of the ultrasonic wave (step A6).
The unit 101 calculates each position of the ultrasonic microphones 12a to 12e, that is, the two-dimensional position of each fingertip from two time differences calculated above (step A7).
The unit 101 performs the procedure so that the correction ultrasonic speaker 14 outputs an ultrasonic wave (step B1), and the correction ultrasonic microphone 15 detects the ultrasonic wave (step B2). The unit 101 measures the time difference (lag) from the output to detection of the ultrasonic wave (step B3).
Then, unit 101 performs the procedure so that the ultrasonic speaker 11R outputs an ultrasonic wave (step B4), and the correction ultrasonic microphone 15 detects the ultrasonic wave (step B5). The unit 101 measures the time difference from the output to detection of the ultrasonic wave (step B6).
The unit 101 calculates a position detection error by a two-dimensional change in speed of sound resulting from the hand action, wind, etc. from two time differences calculated above, and thereafter, corrects it (step B7).
The action detecting unit 102 determines whether or not the acceleration value outputted from the acceleration sensors 13a to 13e is less than a negative threshold value (step C1, step C2). If the outputted acceleration value is less than the negative threshold value (YES in step C2), the unit 102 determines whether or not the outputted acceleration value is more than a positive threshold value (step C3, step C4).
If the acceleration value is more than a positive threshold value (YES in step C4), the unit 102 again determines whether or not the outputted acceleration value is less than the negative threshold value (step C5, step C6). If the acceleration value is again less than the negative threshold value (YES in step C6), the unit 102 determines whether or not a series of changes confirmed according to the checks from step C1 to step C6 occurs within a predetermined time (step C7). If the change occurs within the predetermined time (YES in step C7), the unit 102 detects an operation by a finger attached with the acceleration sensor (step C8).
The information input apparatus 1 of the embodi-ment having the configuration described above uses ultrasonic speakers, ultrasonic microphones and acceleration sensors. Therefore, the information input apparatus 1 has low power consumption and is excellent in portability. In addition, each fingertip portion of each of the five fingers is attached with the foregoing ultrasonic microphone and acceleration sensor, and the fingertip position and action of the freely acting finger are detected. Therefore, information input speed is improved as well as keyboard input, and input contents becomes difficult to be guessed at by other persons. Moreover, it is possible to correct an error caused by a change in speed of sound resulting from hand action, wind, etc.
In the foregoing embodiment, ultrasonic speakers 11R and 11L are attached to both ends of the wrist while ultrasonic microphones 12a to 12e are attached to fingertips. Alternatively, for example, as shown in
In the foregoing embodiment, the ultrasonic microphone and acceleration sensor are attached to all five fingers. Alternatively, they may be attached to a predetermined finger only. The number of attached ultrasonic microphones and acceleration sensors may be mutually different. The present invention is not limited to key input, and is applicable to the operation of various electronic appliances.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
---|---|---|---|
2004-134498 | Apr 2004 | JP | national |