JP5177033B2 - Input device and electronic device - Google Patents

Description

  The present invention relates to an input device and an electronic device.

  Conventionally, an ultrasonic sensor that transmits ultrasonic waves and receives ultrasonic waves reflected by an obstacle is known. As such an ultrasonic sensor, an obstacle sensor mounted on an automobile is disclosed (for example, see Patent Document 1). The ultrasonic sensor of Patent Document 1 transmits ultrasonic waves from an element capable of transmitting and receiving ultrasonic waves, and receives the ultrasonic waves reflected by the object to be detected by this element. Thereby, position measurement or distance measurement of an object around the automobile, measurement of the two-dimensional shape or three-dimensional shape of the object, and the like are performed.

JP 2008-99103 A

  In recent years, the use of an ultrasonic sensor for an input device of an electronic device such as a PDA (Personal Data Assistance) or a PC (Personal Computer) has been studied, but no specific configuration has been proposed yet. However, even if the conventional ultrasonic sensor is used as an input device, there are the following problems.

The ultrasonic sensor of Patent Document 1 is used for in-vehicle use, and is for detecting the position, distance, shape, and the like of a large obstacle existing at a relatively long distance. In order to measure an obstacle at a long distance using an ultrasonic sensor, it is necessary to set the frequency low and lengthen the wavelength in order to avoid attenuation of the ultrasonic wave.
However, when the wavelength of the ultrasonic wave becomes longer, the resolution for detecting the measurement and operation of the three-dimensional position of the detection target decreases. Therefore, in such an ultrasonic sensor, as a support for performing an input operation, for example, a three-dimensional object of a relatively small detection target existing at a short distance, such as the movement of a human hand or the operation of an input pen or the like. There is a problem that the position, shape, and speed cannot be detected accurately.

  The present invention has been made to solve the above-described problem, and an object thereof is to provide an input device and an electronic apparatus that can accurately detect the position of an indicator.

  The input device of the present invention is an input device for inputting information by an indicator having a plurality of regions having different ultrasonic reflectivities, the plurality of transmitting elements for transmitting the ultrasonic waves, and the indication of the ultrasonic waves A receiving element that receives a reflected wave from the body; and an electric signal is supplied to the transmitting element, and an ultrasonic wave is transmitted to a region where the indicator is disposed, and then the first reflectance of the indicator is set. The position coordinates of the first reflection area are detected on the basis of the difference between the intensity of the reflected wave from the first reflection area and the intensity of the reflected wave from the second reflection area having the second reflectance. And a control unit that determines this as the input information.

  According to this configuration, the control unit can discriminate between the first reflection area and the second reflection area of the indicator based on the difference in the reflectance of the ultrasonic wave. Instead of detecting, it is possible to provide an input device that can detect the position of a specific part in the indicator and accurately detect the position coordinates of the first reflection region as input information.

It is preferable that the control unit detects an extending direction of the indicator by detecting a position coordinate of the second reflection area with reference to the first reflection area.
According to this, since the schematic shape of the indicator near the first reflection region can be recognized by detecting the extending direction of the indicator, not only the position coordinates of the first reflection region, The extending direction of the support can be used as input information. Therefore, it is possible to provide an input device capable of increasing input information and realizing a more complicated input operation.

Preferably, the control unit includes a plurality of the transmitting elements, and the control unit outputs the signal that causes the plurality of transmitting elements to transmit the ultrasonic wave having the same phase toward one direction of the region.
According to this, since an ultrasonic wave with improved directivity can be transmitted, an input device with improved resolution can be provided.

It is preferable that the control unit divides a scanning region facing the transmitting element into a plurality of partial regions and intermittently sequentially transmits the ultrasonic waves toward the partial regions.
According to this, since it is possible to scan the scanning region while suppressing the number of times of transmitting ultrasonic waves, it is possible to provide an input device that can detect the position coordinates of the indicator in a short time.

The control unit normalizes an amplitude of the reflected wave according to a distance between the receiving element and the indicator, and the first reflected wave having a normalized amplitude of the reflected wave is equal to or greater than a predetermined amplitude. It is preferable to detect the position coordinates of the region.
According to this, since the amplitude of the reflected wave that fluctuates due to a change in the distance from the receiving element can be corrected, it is possible to reliably determine the first reflection area and the second reflection area of the indicator. An input device that can be provided can be provided.

The control unit detects a position coordinate of the first reflection area where the normalized reflected wave has an amplitude greater than or equal to a predetermined amplitude, and then detects a position in a local area near the position coordinate of the first reflection area. It is preferable to scan with the ultrasonic wave to detect the detailed position coordinates of the first and second reflection regions of the indicator and the detailed extending direction.
According to this, after detecting the approximate position coordinates of the first reflecting area of the indicator by scanning the entire scanning area, only a narrow area including the first reflecting area is scanned in detail with ultrasound. Therefore, it is possible to detect the detailed position coordinates of the first and second reflection areas of the indicator. Further, it is possible to provide an input device that can easily detect the schematic shape of the indicator near the first reflection region.

The control unit determines the validity of the detected position coordinates of the first reflection area and the extension direction of the indicator, and the position coordinates of the first reflection area and the extension direction of the indicator are valid. If it is determined that the position coordinates of the indicator are re-detected by scanning the inside of the local region with the ultrasonic waves.
The “effectiveness of the position coordinates of the first reflection area and the direction in which the indicator extends” here refers to input information (position coordinates of the first reflection area, the indication of the indicator that matches the information required by the input device). This means that the extending direction) has been detected.
Therefore, when valid input information is detected, it is only necessary to detect the movement of the indicator by scanning only the local area set immediately before, so that the movement of the indicator can be tracked in a short time. An input device can be provided.

The control unit determines the validity of the detected coordinates of the first reflection area and the extension direction of the indicator, and the position coordinates of the first reflection area and the extension direction of the indicator are not valid. If it is determined that the position coordinates of the indicator are redetected by scanning the entire scanning area.
According to this, since the movement of the indicator can be detected even when the indicator moves to a position coordinate deviating from the previously set local area, the movement of the indicator can be reliably tracked. An input device can be provided.

It is preferable that a plurality of the indicators are arranged to face the transmitting element, and the control unit detects the position coordinates of the first reflection area of each of the indicators and determines these as the information. .
According to this, since it is possible to detect input information of a plurality of indicators, it is possible to provide an input device that can realize a more complicated input operation such as a positional relationship between the indicators.

Preferably, the control unit detects a finger as the indicator, detects a nail as the first reflection region, and skin as the second reflection region.
According to this, since the input operation can be executed by detecting the position coordinates of the nail having high hardness and high reflectance, that is, the position coordinates of the fingertip, an input operation indicator is not required separately, and the input operation can be performed. Operation is simplified.

An electronic apparatus according to the present invention includes the input device described above.
According to this, since the input device can execute the input operation by detecting the position coordinates of the indicator, it is possible to provide an electronic device that simplifies the input operation.

It is a perspective view of PDA. It is a perspective view of an input device. It is a top view which shows the example of arrangement | positioning of a transmitting element and a receiving element. It is A-A 'sectional drawing in FIG. It is a circuit block diagram of a control part. It is a figure which shows an example of the pulse input into a transmission element. It is explanatory drawing of the coordinate system of an area | region. It is a flowchart figure which concerns on the position detection of a finger | toe. It is a figure which shows an example of the method of dividing | segmenting an area | region into several partial area | regions. It is a figure which shows an example of the normalized reflected wave. It is an enlarged view of a local region. It is a figure which shows an example of the normalized reflected wave. It is a figure which shows the reflected wave in a circumferential area | region.

Hereinafter, an input device according to the present invention will be described with reference to the drawings.
The following embodiments show one aspect of the present invention and do not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structural member easy to understand, the scale and number of each structural member are different from the actual configuration.

FIG. 1 is a perspective view schematically showing a PDA 100 which is an example of an electronic apparatus including the input device of the present invention. As shown in FIG. 1, the PDA 100 includes a main body 30, a display unit 20, and an input device 10.
The display unit 20 is an area for displaying an image, and is configured integrally with the main body 30.
The input device 10 is disposed on the main body 30 around the display unit 20. The input device 10 detects the coordinates of the finger F by transmitting an ultrasonic wave to the scanning region R above the display unit 20 and receiving a reflected wave from the finger (indicator) F arranged in the scanning region R. .
Therefore, for example, when a plurality of selection buttons are displayed on the display unit 20, the user can select an arbitrary button by holding the fingertip above the button to be selected. Further, by detecting the fingertip coordinates and the finger skin coordinates, an arbitrary button can be selected by detecting the extending direction of the finger F. Furthermore, any button can be selected by detecting the movement of the finger.

Next, the input device 10 will be described in detail.
FIG. 2 is a perspective view schematically showing a detailed configuration of the input device 10. FIG. 3 is a plan view schematically showing an arrangement example of the transmitting element 1 a and the receiving element 1 b in the ultrasonic sensor 1. FIG. 4 is a diagram schematically showing a cross-sectional shape along AA ′ in FIG. 2. FIG. 5 is a circuit block diagram of the control unit 40A. FIG. 6 is a diagram illustrating an example of pulses input to the transmitting element 1a.

As shown in FIG. 2, the input device 10 includes an ultrasonic sensor unit 1A and a control unit 40A. The ultrasonic sensor unit 1 </ b> A includes a substrate 11 and the ultrasonic sensor 1.
As shown in FIG. 3, the ultrasonic sensor 1 has a configuration in which a plurality of transmitting elements 1a and a plurality of receiving elements 1b are arranged in a matrix on a surface 11A of a substrate 11.
In the present embodiment, as shown in FIG. 3, the receiving elements 1b are arranged at four corners and four central parts of the ultrasonic sensor 1, and the transmitting elements 1a are arranged at other positions. It is a configuration.

As shown in FIG. 4, the transmitting element 1 a and the receiving element 1 b in a cross-sectional view have the same configuration, and include a diaphragm 2, a lower electrode 4, a piezoelectric body 3, and an upper electrode 5. Yes.
The substrate 11 is made of rectangular single crystal silicon. An opening 11a is formed in a portion of the entire surface of the substrate 11 corresponding to the transmitting element 1a and the receiving element 1b.
A laminated film in which a first oxide film 2a made of SiO ₂ (silicon dioxide) and a second oxide film 2b made of ZrO ₂ (zirconia) are laminated on almost the entire surface 11A of the substrate 11 is formed. Has been. A portion of the laminated film corresponding to the upper portion of the opening 11 a functions as the diaphragm 2.
The first oxide film 2a is formed by thermally oxidizing the surface of the single crystal silicon substrate and has a film thickness of about 3 μm. The second oxide film 2b is formed by a CVD method (chemical vapor deposition method) or the like and has a thickness of about 400 nm.

  The lower electrode 4 is formed on the diaphragm 2. More specifically, the film of the lower electrode 4 is formed on almost the entire surface of the second oxide film 2b, and serves as a common electrode for all the transmitting elements 1a and the receiving elements 1b constituting the ultrasonic sensor 1. The lower electrode 4 is made of a conductive metal material such as Ir (iridium) and has a thickness of about 200 nm.

The piezoelectric body 3 is formed only in a region of the entire surface of the lower electrode 4 that is above the opening 11a. The piezoelectric body 3 is formed of PZT (lead zirconate titanate), BaTiO ₃ (barium titanate) or the like, and has a film thickness of about 1.4 μm.
The upper electrode 5 is formed on the piezoelectric body 3. The upper electrode 5 is made of a conductive metal material such as Ir (iridium) and has a film thickness of about 50 nm.

  As shown in FIG. 2, the flexible printed circuit board 12 connects the ultrasonic sensor unit 1A and the control unit 40A. Specifically, the terminal part 11T of the ultrasonic sensor unit 1 and the terminal part 13T formed on the surface 13a of the control board 13 of the control part 40A are electrically connected.

The control unit 40A includes a control board 13 and a control circuit 40 as shown in FIG.
The control circuit 40 is mounted on the surface 13 a of the control board 13 and controls the ultrasonic sensor 1.
Here, the control circuit 40 will be described in detail. As illustrated in FIG. 5, the control circuit 40 includes a control calculation unit 41, a storage unit 42, an ultrasonic wave generation unit 43, and an ultrasonic wave detection unit 44.

  The control calculation unit 41 outputs a signal for driving each transmission element 1 a to the ultrasonic wave generation unit 43 and is also received by the reception element 1 b and input via the storage unit 42 as a reflected wave signal (hereinafter, reflected). The position and extension direction of the finger F are detected based on the signal). And based on the detected information, the input information with the finger | toe F is acquired and it outputs to the main body 30 of FIG.

The ultrasonic generator 43 includes a sine wave generator 43a, a phase unit 43b, and a driver 43c, and outputs an electric signal for generating ultrasonic waves to the transmitting element 1a.
The sine wave generation unit 43a generates a sine wave-like pulse (electric signal) and outputs it to the phase unit 43b.
The phase unit 43b shifts the phase of the pulse based on the transmission signal input from the control calculation unit 43b. Then, after the amplitude of the pulse whose phase has been shifted is amplified by the driver 43c, the pulse is output to the transmitting element 1a.

The ultrasonic receiving unit 44 receives the reflected wave reflected by the finger F and outputs it to the control calculation unit 41. The ultrasonic receiving unit 44 includes an amplification unit 44a and an A / D conversion unit 44b.
The amplifier 44a amplifies the amplitude of the reflected signal received by the receiving element 1b and outputs the amplified signal to the A / D converter 44b.
The A / D converter 44b converts the reflected signal input from the amplifier 44a into a digital signal and outputs the digital signal to the A / D converter 44b.

  The storage unit 42 stores various data such as the reflection signal of the receiving element 1b digitally converted by the A / D conversion unit 44b, the transmission direction and transmission time of the ultrasonic wave, and the reception time of the reflected wave. The storage unit 42 stores a program for controlling the input device 10, a set value, and the like.

Hereinafter, the operation of the control circuit 40 will be described.
When the pulse shown in FIG. 6 is input to the transmitting element 1a, a potential difference is generated between the lower electrode 4 and the upper electrode 5 in accordance with the amplitude of the pulse. As a result, the piezoelectric body 3 expands and contracts in the normal direction of the surface 11 </ b> A of the substrate 11 to vibrate the diaphragm 2. Then, the air in the opening 11a vibrates, and ultrasonic waves are transmitted to the scanning region R above the display unit 20 in FIG.
On the other hand, when the reflected wave reflected by the finger F is received by the receiving element 1 b, the diaphragm 2 vibrates and the piezoelectric body 3 expands and contracts in the normal direction of the surface 11 A of the substrate 11. Then, a potential difference is generated between the lower electrode 4 and the upper electrode 5, and a pulsed electric signal is output to the ultrasonic receiver 44.

Here, a coordinate system for defining the coordinates of the finger F arranged in the scanning region R will be described. FIG. 7 is an explanatory diagram of the coordinate system of the scanning region R.
First, with the center point O of the ultrasonic sensor unit 1A as a reference point, the distance of a line segment OT connecting the point O and the point T in the scanning region R is defined as a d coordinate.
Next, as shown in FIG. 7, the intersection of the normal drawn from the point O and the scanning region R is defined as O1. A line segment connecting the point O and the point O1 is referred to as a reference axis O-O1.
The angle formed by the line segment OT1 projected onto the x-axis and the reference axis O-O1 is defined as the θ coordinate, and the line segment OT2 obtained by projecting the line segment OT onto the y-axis is defined as the reference axis O-O1. Let the angle be the Φ coordinate. Thus, the coordinates (d, θ, Φ) of the scanning region R are defined.

Next, an operation related to the coordinate detection of the finger F in the input device 10 having such a configuration will be described.
FIG. 8 is a flowchart for detecting the position of the finger F. The coordinate detection of the finger F includes steps S10 for scanning the entire surface of the scanning region R with ultrasonic waves, step S20 for normalizing the reflected signal of the reflected wave reflected by the finger F according to the distance from the receiving element 1b, Step S30 for detecting the fingertip coordinates from the standardized reflected wave, Step S40 for scanning only a narrow region including the fingertip in detail with ultrasonic waves, and detecting the detailed coordinates of the nail from the reflected wave data near the fingertip Step S50, step S60 for detecting the detailed coordinates of the fingertip skin and the extending direction of the finger, step S70 for determining the effectiveness of the detected nail coordinates and the extending direction of the finger, and Step S80 for outputting information on the coordinates of the nail determined to be present and the extending direction of the finger to the main body 30 is executed.

First, in step S10, the entire surface of the scanning region R is scanned with ultrasonic waves to obtain reflected wave data. In the present embodiment, the scanning region R is divided into a plurality of partial regions along the θ direction and the Φ direction, and the scanning region R is scanned by transmitting ultrasonic waves toward each partial region.
FIG. 9 is a diagram illustrating an example of a method for dividing the scanning region R into a plurality of partial regions. The scanning region R shown in FIG. 9 is divided into eight (θ1,..., Θm,..., Θ8) in the θ direction and eight (Φ1,..., Φn,. These partial areas are represented as r (m, n) using a column number m in the θ direction and a row number n in the Φ direction.

  The control circuit unit 41 outputs a transmission signal to the phase unit 43 b of the ultrasonic wave generation unit 43. The control circuit unit 41 forms a transmission signal having a different phase for each transmission element 1a so that the ultrasonic waves that reach the partial region r (m, n) have the same phase. In this way, the scanning region R is scanned by forming ultrasonic waves with improved directivity.

  The reflected wave reflected by the finger F is received by the receiving element 1b. Then, after the reflected wave is converted into a pulsed electric signal (reflected signal) in the receiving element 1 b, it is output to the ultrasonic detector 44. The reflected signal is digitally converted by the A / D conversion unit 44 b of the ultrasonic detection unit 44 and output to the control circuit unit 41 via the storage unit 42.

  Next, the process proceeds to step S20. In step S20, the amplitude of the received reflected signal is normalized. Normalization means that the amplitude of the reflected wave is corrected according to the distance between the receiving element 1b and the finger F. The energy density of ultrasonic waves is inversely proportional to the square of the distance from the ultrasonic sensor unit 1A. That is, as the distance from the ultrasonic sensor unit 1A to the finger F increases, the ultrasonic amplitude decreases. Therefore, the amplitude is normalized by correcting the attenuated amplitude.

In order to perform normalization, first, information such as the transmission time of each ultrasonic wave, the transmission direction, and the reception time of the reflected wave is read from the storage unit 42.
Then, the distance d (θ, Φ) from the ultrasonic wave transmission time, the reflected wave reception time, and the ultrasonic sound velocity to the finger F reflecting the ultrasonic wave is detected. If the amplitude of the reflected signal is I (θ, Φ) and the normalized amplitude is I _nrm (θ, Φ), then I _nrm (θ, Φ) = I (θ, Φ) / d (θ, Φ) The amplitude of the reflected wave is normalized by the equation ( ² ).
Thus, when the amplitude of the reflected wave is normalized, the process proceeds to step S30.

In step S30, the coordinates of the fingertip including the nail are detected from the _normalized amplitude I _nrm (θ, Φ).
Here, FIG. 10 is a diagram illustrating an example of a normalized reflected wave waveform. In FIG. 10, the reflected wave of the fingertip including the nail is displayed with a broken line, and the reflected wave from the skin of the finger not including the nail is displayed with a solid line. Since the nail has a higher hardness than the skin and the reflectance of the nail (first reflectance) is higher than the reflectance of the skin (second reflectance), as shown in FIG. 10, the reflected wave from the fingertip Has a larger amplitude than the reflected wave from the skin.

Therefore, an amplitude larger than the amplitude of the reflected wave of the skin and smaller than the amplitude of the reflected wave of the nail is set as the reference amplitude Vs, and the control circuit unit 41 has a partial region (first region) showing an amplitude larger than the reference amplitude Vs. The coordinates of the reflection area) and the partial area (second reflection area) showing an amplitude smaller than the reference amplitude Vs are detected. Then, the coordinates of the partial region r (m, n), which is the first reflection region, are detected as fingertip coordinates P01 (θ, Φ),..., P05 (θ, Φ). The fingertip coordinates P01 to P05 shown here correspond to five fingers, respectively.
In the present embodiment, the following steps will be described by taking as an example the case where a fingertip is detected in the partial region r (4, 5), that is, θ4 in the θ direction and φ5 in the φ direction.

  The fingertip coordinates P01 (θ, Φ) detected in step S30 are detected by scanning the entire scanning region R, and are not a detailed determination of the nail position and the fingertip skin position. The approximate position is detected. Therefore, in the subsequent steps, only a narrow area near the fingertip is scanned in detail with ultrasound to detect accurate nail coordinates and skin coordinates.

When the process proceeds to step S40, the local region R1 including only the narrow region including the fingertip coordinates P01 (θ, Φ) detected in step S30 is scanned with ultrasonic waves, and detailed reflected waves from the local region near the fingertip are scanned. Get information.
Here, as shown in FIG. 9, the local region R1 is divided into a partial region r (4, 5) including the fingertip coordinates P01 (θ, Φ) and a partial region surrounding the partial region r (4, 5). A region to be configured is defined as a local region R1. That is, the local region R1 is composed of nine partial regions.

FIG. 11 is an enlarged plan view showing the local region R1. As shown in FIG. 11, the local region R1 is divided into a plurality of minute regions r1 along the θ direction and the Φ direction, and each partial region r (m, n) is further divided into smaller regions.
Then, ultrasonic waves are sequentially transmitted toward each minute region r1, and the entire region of the local region R1 is scanned in detail. At this time, the ultrasonic wave transmission direction and the transmission time are stored in the storage unit 42 as in step S10.
On the other hand, the reflected wave from the finger F is received by the receiving element 1 b, and the reflected signal digitally converted by the ultrasonic wave receiving unit 44 is input to the control circuit unit 41 via the storage unit 42. In addition, the reception time of the reflected wave is stored in the storage unit 42.
Thus, when the scanning of the local region R1 is completed, the process proceeds to step S50.

In step S50, detailed nail coordinates are detected based on the reflection signal from the local region R1 acquired in step S40.
The control circuit unit 41 reads information such as the transmission time of each ultrasonic wave, the coordinate information of the minute region R, the reflected signal and the reception time of the reflected wave from the storage unit 42, and normalizes the amplitude of the received signal.

FIG. 12 is a diagram illustrating an example of a reflected wave from the normalized local region R1. In FIG. 12, the vertical axis represents the normalized amplitude I _nrm (θ, Φ) of the reflected wave, and the horizontal axis represents the angle θ. That is, FIG. 12 shows the amplitude of the reflected wave from the minute region r1 arranged in a certain Φ direction.
As shown in FIG. 12, the amplitude of the reflected wave is classified into a region Z1 that is a reflected wave from the nail having a large amplitude and a region Z2 that is a reflected wave from the skin having a small amplitude. In FIG. 12, the display of the plurality of regions Z1 indicates that a plurality of fingers are detected in the local region R1. The control circuit unit 41 detects the coordinates indicating the maximum amplitude in the region Z1 as the claw coordinates P11 (θ, Φ).
As described above, when the nail coordinate P11 (θ, Φ) is detected, the process proceeds to step S60.

In step S60, the extending direction of the finger F is detected based on the reflection signal from the local region R1 acquired in step S40.
In order to detect the extending direction of the finger F, first, as shown in FIG. 11, an annular region Circle that is separated from the nail coordinates P11 (θ, Φ) by a certain distance is set. And the direction which shows the maximum amplitude among the reflected signals of the micro area | region r1 on the area | region Circle is made into the extending direction of the finger | toe F. FIG.

  FIG. 13 is a diagram illustrating the amplitude of the reflected wave in the circumferential region Circle. In FIG. 13, the vertical axis represents the normalized reflected wave amplitude, and the horizontal axis represents the angle ρ illustrated in FIG. 11. Here, the angle ρ is defined by an angle formed by the line segment P11Q1 with the θ axis with respect to the θ axis direction. As shown in FIG. 13, the reflected wave in the circumferential region Circle has the maximum amplitude in a minute region in the direction of the angle ρ1. Therefore, it can be seen from FIG. 13 that the finger F extends in the direction of the angle ρ1 with reference to the nail coordinates P1 (θ, Φ). Therefore, a vector V1 (θ, Φ) indicating the extending direction of the finger F is defined by V1 (θ, Φ) = Q1 (θ, Φ) −P11 (θ, Φ).

As described above, when the nail coordinates P11 (θ, Φ) and the vector V1 (θ, Φ) are detected by one finger F, the steps S40 to S60 are repeated, and the nail coordinates P21 (θ, Φ) corresponding to each finger are repeated. ˜P51 (θ, Φ) and vectors V2 (θ, Φ) to V5 (θ, Φ) are detected.
Thus, nail coordinates P1 (θ, Φ) (P11 (θ, Φ) to P15 (θ, Φ)) and vectors V (θ, Φ) (V1 (θ, Φ) to V5 corresponding to all fingers are obtained. If (θ, Φ)) is detected, the process proceeds to step S70.

In step S70, the validity of the nail coordinates P (θ, Φ) and the vector V (θ, Φ) detected in steps S50 and S60 is determined.
Here, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are determined to be valid because the detected nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are appropriate. This is a case where it is determined that the input information is correct.
Specifically, this is a case where a button displayed on the display unit 20 is selected based on input information detected by the input device, and an input operation is executed.
As described above, when it is determined that the nail coordinates P (θ, Φ) and the vector V (θ, Φ) are appropriate input information (valid), the process proceeds to step S80.

On the other hand, when it is determined that the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are not appropriate input information (invalid), the process returns to step S10, and the entire scanning region R is rescanned. Then, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are detected again.
Specifically, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are determined to be invalid because the button displayed on the display unit 20 cannot be selected based on the detected input information. When the operation is not executed or when the fingertip is scanned in detail in step S40, the finger F moves to a region outside the local region R1, and the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) ) Is not detected.
As a result of the re-detection, when appropriate nail coordinates P1 (θ, Φ) and vector V (θ, Φ) are detected, the process proceeds to step S80.

In step S80, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are output to the main body 30. In the main body 30, processing based on the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) output from the input device 10 is performed.
Then, if necessary, the process proceeds to step S40, the fingertip is tracked, and the position detection operation is continuously performed to detect the movement of the finger. In step S40, only the local region R1 defined immediately before is rescanned to detect new nail coordinates P1 (θ, Φ) and vector V (θ, Φ). Even if the fingertip deviates from the local region R1, it is determined that the detected nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are invalid in step S70, and the process proceeds to step S10 to move to the scanning region. The fingertip is tracked by rescanning the entire area of R, and the movement of the finger is detected.

The input device 10 having such a configuration can obtain the following effects.
First, the input device 10 according to the present invention includes an ultrasonic reflectance (first reflectance) in the nail (first reflective region) and an ultrasonic reflectance (second reflectance) in the skin (second reflective region). The nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are detected by discriminating the difference from the reflectance. Thereby, since the position of the fingertip that is a relatively small detection target can be detected also by ultrasonic waves, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) can be used as input information. Further, by determining not only the nail coordinates P1 (θ, Φ) but also the vector V (θ, Φ) as input information, the input information detected by the input device 10 can be increased.

  In the present embodiment, the extending direction of the finger is defined by the vector V (θ, Φ), and the approximate shape of the finger is recognized. According to this, it is possible to easily recognize the approximate shape of the finger rather than recognizing the detailed shape of the three-dimensional finger. Therefore, it is possible to easily acquire data on the extending direction of the finger as input information.

In the present embodiment, in step S10, the scanning region R is divided into a plurality of partial regions r (m, n), and each partial region r (m, n) is scanned, so that the entire scanning region R is scanned. Scanning. In step S40, the nail coordinates P1 (θ, Φ) and the skin coordinates Q (() are scanned in detail by scanning only the local area in the vicinity of the fingertip coordinates P0 (θ, Φ) detected by the full scan of the scanning area R. θ, Φ) are detected.
According to this, the nail coordinates P1 (θ, Φ) and the skin coordinates Q (θ, Φ) can be detected in a shorter time than when the entire scanning region R is scanned in detail.

  In this embodiment, the effectiveness of the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) detected in step S70 is determined, and the nail coordinates P1 (θ, Φ) determined as appropriate input information. ) And the vector V (θ, Φ) are output to the main body 30. When inappropriate input information is detected, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) are re-detected. According to this, since only appropriate input information is output from the input device 10 to the main body 30, the detection accuracy of the input device 10 can be improved.

  In this embodiment, after the input information is output to the main body 30, only the local region R1 set immediately before is rescanned in detail to track the position of the finger F. According to this, since the detailed position of the finger F can be detected without scanning the entire scanning region R again, the finger F can be tracked in a short time.

  Further, in the present embodiment, the nail coordinates P1 (θ, Φ) and the vector V (θ, Φ) indicating the extending direction of the finger are detected. Φ) may be input information. In this case, since it is not necessary to perform detailed scanning of the fingertip after step S40, detection of input information can be performed in a shorter time.

  In the present embodiment, the finger F is exemplified as the indicator, but a thing other than the finger F can be used as the indicator. For example, a bar-shaped member such as a pen or a bar, which is made of a material having a different tip, is preferable. If it has such a structure, the reflectance in a front-end | tip and another area | region will differ, and the position of a front-end | tip can be detected correctly.

  In this embodiment, after the entire scanning region R is scanned in step S10, the vicinity of the fingertip is scanned in detail in step S40. However, only the entire scanning region R is scanned to detect input information. You may do it. In this case, the validity of the input information may be determined based on the fingertip coordinates P0 (θ, Φ).

  In the present embodiment, a plurality of transmitting elements 1a and receiving elements 1b are arranged, but each may be a single element. Even in this case, the position of the finger F can be detected.

  In addition, said electronic device is an example of the electronic device of this invention, Comprising: The technical scope of this invention is not limited. For example, the input device of the present invention can be suitably used for display units such as PCs, mobile phones, portable audio devices, and display devices.

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic sensor, 2 ... Diaphragm, 3 ... Piezoelectric body, 4 ... Lower electrode, 5 ... Upper electrode, 1A ... Ultrasonic sensor unit, 1a ... Transmitting element, 1b ... Receiving element, 10 ... Input device, 11 ... Base: 12 ... Flexible printed circuit board, 13 ... Control board, 14 ... Control part, 40 ... Control circuit, 41 ... Control operation part, 42 ... Storage part, 43 ... Ultrasonic wave generation part, 43a ... Sine wave generation part, 43b ... Phase unit 44 ... Ultrasonic detection unit 44b A / D conversion unit 100 PDA (electronic device) R Scan region R1 Local region

Claims (11)

An input device for inputting information by an indicator having a plurality of regions having different ultrasonic reflectivities,
A plurality of transmitting elements for transmitting the ultrasonic waves;
A receiving element for receiving a reflected wave of the ultrasonic wave from the indicator;
After supplying an electrical signal to the transmitting element and transmitting an ultrasonic wave to a region where the indicator is disposed, a reflected wave from a first reflecting region having a first reflectance of the indicator is transmitted. A control unit that detects the position coordinates of the first reflection area based on the difference between the intensity and the intensity of the reflected wave from the second reflection area having the second reflectance, and determines this as the input information When,
An input device comprising:   The control unit detects an extending direction of the indicator by detecting a position coordinate of the second reflection area with reference to a position coordinate of the first reflection area. The input device described. Comprising a plurality of the transmitting elements;
The input device according to claim 1, wherein the control unit outputs the electrical signal that causes the plurality of transmitting elements to transmit the ultrasonic wave having the same phase in one direction of the region. .   The control unit divides a scanning region facing the transmitting element into a plurality of partial regions, and outputs the electrical signal that sequentially and sequentially transmits the ultrasonic waves toward the partial regions. The input device according to any one of claims 1 to 3.   The control unit normalizes an amplitude of the reflected wave according to a distance between the receiving element and the indicator, and the first reflected wave having a normalized amplitude of the reflected wave is equal to or greater than a predetermined amplitude. The input device according to claim 1, wherein position coordinates of the region are detected.   The control unit, after detecting the position coordinates of the first reflection area, scans the ultrasonic wave in a local area near the position coordinates of the first reflection area, and thereby performs the first and first of the indicator. 6. The input device according to claim 2, wherein detailed coordinates of the two reflection areas and the detailed extending direction are detected.   The control unit determines the validity of the detected position coordinates of the first reflection area and the extension direction of the indicator, and the position coordinates of the first reflection area and the extension direction of the indicator are valid. The input device according to claim 6, wherein when it is determined that the position coordinates of the indicator are redetected by scanning the ultrasonic wave only in the local region.   The control unit determines the validity of the detected position coordinates of the first reflection area and the extension direction of the indicator, and the position coordinates of the first reflection area and the extension direction of the indicator are valid. The input device according to claim 6, wherein if it is determined that the position of the indicator is not, the position coordinates of the indicator are redetected by scanning the entire scanning region. When a plurality of the indicators are arranged facing the transmitting element,
The said control part detects the position coordinate of the said 1st reflective area | region of each said indicator, and judges these as the said input information, The any one of Claim 1 to 8 characterized by the above-mentioned. Input device.   10. The control unit according to claim 1, wherein the control unit detects a finger as the indicator, detects a nail as the first reflection region, and skin as the second reflection region. 11. The input device described in 1.   An electronic apparatus comprising the input device according to claim 1.

Images