Information presentation device using tactile stimulus with vibrator

An information presentation device transmits information of a car navigation system, installed in a vehicle, to a driver in form of tactile stimuli, wherein a controller controls a plurality of vibrators attached to a steering wheel. The vibrators are arranged in proximity to vibration transmitters, corresponding to holding parts of a steering wheel, so that they are controlled with desired vibration intensity and vibration start timing in response to drive signals from the controller. Two vibrators are arranged in the holding parts of a steering wheel which come in contact with driver's hands and are controlled to generate a virtual vibrating source, thus rendering a driver feeling a sensation as if a vibrating source is moving in upward-downward directions, left-right directions, and far-near directions in the front side of a driver. Thus, it is possible to present accurate information with a small amount of energy consumption in driving vibrators.

TECHNICAL FIELD

The present invention relates to an information presentation device using a tactile stimulus with a vibrator.

The present application claims priorities on Japanese Patent Application No. 2009-278925 (filing date: Dec. 8, 2009) and Japanese Patent Application No. 2010-147629 (filing date: Jun. 29, 2010), the entire contents of which are incorporated herein by reference.

BACKGROUND ART

Conventionally, information presentation devices presenting operators of vehicles with vehicle information using tactile stimuli have been known. PLT 1 disclosed an information presentation device including a plurality of vibrators attached to a vehicle's seat and a detector for detecting a moving direction of a moving body that exists in the periphery of a vehicle. Among a plurality of vibrators, the information presentation device sequentially drives at least two vibrators, which are related to the moving direction of a moving body detected by the detector, so as to present an operator with information of a moving body.

PLT 2 disclosed an information presentation device including a plurality of vibrators attached to a vehicle's seat and a detector for detecting a hazardous situation of a vehicle. Among a plurality of vibrators, the information presentation device selects two or more vibrators in response to a hazardous situation of a vehicle detected by the detector so as to drive those vibrators differently with respect to at least one of a vibration frequency, time, amplitude, and a vibration interval. Herein, it adjusts a vibration frequency, time, amplitude, and a vibration interval to tactile sensation characteristics of a human body such that a vehicle's operator can sense an apparent movement phenomenon, thus presenting the operator with alert information using a pattern representing a hazardous situation detected by the detector.

Additionally, the information presentation devices of PLT 1 and PLT 2 are each designed to arrange vibrators on the surface of a vehicle's seat and drive them so that tactile stimuli will be transmitted to the thigh and the back of a vehicle's operator.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

The thigh and the back of a human body are regarded as areas with a relatively rarefactional distribution of organoleptic cells so that they exhibit a relatively low sensitivity to tactile stimuli in comparison with the palm of the hand and fingertips with a relatively dense distribution of organoleptic cells reacting to tactile stimuli. For this reason, the information presentation devices of PLT 1 and PLT 2 need to increase stimulus intensity to an operator by increasing vibrating intensity of vibrators in order to securely transmit information to a vehicle's operator, so that they are likely to increase the amount of energy consumed for driving vibrators.

Solution to Problem

The present invention is made in consideration of the foregoing circumstances, wherein the object thereof is to provide an information presentation device that is able to accurately transmit information to an operator with weak stimulus intensity transmitted to a vehicle's operator.

An information presentation device of the present invention presents an operator with externally provided information in form of vibration, wherein it includes a manual control part (e.g. a steering wheel) having a shape held by an operator's hand; at least one vibrator attached to the manual operation part; a controller that generates a driver signal to control the vibrator based on the externally provided information; and a vibration transmitter that transmits vibration of the vibrator, applied to the manual control part, as a tactile stimulus to an operator's hand.

It is possible to arrange a plurality of vibrators in the manual control part, wherein the controller is able to sequentially drive a plurality of vibrators with a time difference between their vibration start timings. In this case, the controller may generate a drive signal, based on a vibration transmission function established between the vibrator and the vibration transmitter in the manual control part, so as to control the vibrator. The controller may generate a drive signal rendering a frequency-modulated control waveform subjected to frequency sweep over a lapse of time. The controller may generate a drive signal rendering a control waveform multiplexing a plurality of frequency components and changing its mixing ratio with respect to time. The controller may control a plurality of vibrators with different values of vibration intensity. The controller may generate drive signals rendering amplitude-modulated control waveforms with a time-phase difference therebetween. The controller may generate drive signals rendering control waveforms with a discrete time difference, a time-phase difference, and an amplitude difference therebetween.

Advantageous Effects of Invention

An information presentation device of the present invention is designed to convert externally provided information into vibration using vibrators, thus transmitting tactile stimuli to an operator's hand holding a vibration transmitter. It is possible to accurately present information with weak tactile stimuli transmitted to an operator. Thus, it is possible to reduce the amount of energy consumed by the information presentation device.

DESCRIPTION OF EMBODIMENTS

The present invention will be described by way of embodiments with reference to the accompanying drawings. Herein, the same constituent elements are denoted using the same reference signs.

First Embodiment

FIG. 1is a schematic illustration of an information presentation device10according to a first embodiment of the present invention.FIG. 2is a block diagram showing the constitution of the information presentation device10.

The information presentation device10includes a steering wheel11, seven vibrators12(i.e. vibrators12ato12g), switches13a,13b, and a controller14. As shown inFIG. 2, the information presentation device10is connected to an information generator15installed in a car navigation system N.

The steering wheel11is attached to a driver's seat of a vehicle such as an automobile and driven by an operator to steer the vehicle. The external shape of the steering wheel11is a ring shape (or an oval shape) such that the ringed portion thereof is fixed to a steering center11adisposed at a center position. The steering center11ais fixed to a rotary shaft member O equipped with a steering mechanism for steering a vehicle. As a material for use in the steering wheel11, for example, it is possible to employ a resin material, a metal, wood, and a carbon material. Alternatively, it is possible to produce the steering wheel11adequately combining a plurality of materials.

It is preferable that a vibration transmission function inherently ascribed to the material of the steering wheel11can be found by way of measurement or simulation; hence, it is preferable to employ the steering wheel11whose vibration transmission characteristic can be predicted in advance.

The steering wheel11includes two holding parts A1, A2that can be held by an operator. It is preferable that the holding parts A1, A2be positioned at opposite ends in left/right directions in view of an operator situated in front of the steering wheel11which is set to a neutral position (i.e. the position at which the steering wheel11is not steered in either direction about the rotary shaft member O). Additionally, it is preferable that the holding members A1, A2be each shaped with a predetermined length L (e.g. an average of the maximum width of an adult's hand), measuring the maximum width of an operator's hand, extended in a circumferential direction of the steering wheel11.

The holding parts A1, A2of the steering wheel11are equipped with vibration transmitters B1, B2which are able to transmit vibration, caused by the vibrators12ato12g, to an operator who is holding the holding parts A1, A2. In the first embodiment, the vibration transmitters B1, B2are integrally formed with the steering wheel11by use of the same material as the material of the steering wheel11.

In this connection, the vibration transmitters B1, B2may form a part of the steering wheel11; alternatively, they may be formed using material different from the material of the steering wheel11.

The vibrators12ato12gare arranged in one arc portion, sandwiched between the holding parts A1, A2, in the ringed portion of the steering wheel11, wherein they are disposed with equal intervals therebetween in the order of the vibrators12a,12b,12c,12d,12e,12f, and12g.

When observing the steering wheel11in a front view from an operator, the first embodiment arranges the vibrators12ato12gin the upper arc portion of the steering wheel11. Additionally, the vibrators12ato12gare embedded inside the upper arc portion of the steering wheel11. Moreover, it is possible to employ an appropriate shape as the shape of the vibrators12ato12gas long as they can be embedded inside the steering wheel11without projecting from its external surface.

The vibrators12ato12gare connected to a signal wire W1embedded inside the steering wheel11. The signal wire W1is connected to a controller14. The controller14sends drive signals to the vibrators12ato12gvia the signal wire W1.

The vibrators12ato12gare ones that vibrate themselves upon receiving drive signals from the controller14; specifically, it is possible to employ vibration motors which are driven to rotate when a DC voltage is applied to them. Since vibrators12ato12gare embedded in the steering wheel11, vibration caused by the vibrators12ato12gvibrating themselves is transmitted to the steering wheel11so that vibration is further transmitted to the vibration transmitters B1, B2of the steering wheel11.

The switches13a,13bare input parts which allow an operator (e.g. a driver) of a vehicle to operate predetermined devices; for example, it is possible to employ momentary switches. In the first embodiment, the switches13a,13bare positioned at the holding parts A1, A2of the steering wheel11such that they are positioned oppositely to face each other across the rotary shaft member O. The switches13a,13bmay be necessarily arranged within the reachable range in which a driver holding the holding parts A1, A2of the steering wheel11can reach with his/her fingers. Thus, it is possible to arrange the switches13A,13B in proximity to the holding parts A1, A2.

The switches13a,13bare fixed to the steering wheel11such that they are projected inwardly from the inner circumference on the external surface of the steering wheel11. This makes it possible for a driver to easily grope and hold the positions of the switches13a,13b. Additionally, the projecting direction of the switches13a,13bis an inward direction from the ringed portion of the steering wheel11. Thus, an operator is able to easily press and operate the switches13a,13bwhile holding the holding parts A1, A2of the steering wheel11.

As a fixing method of the switches13a,13bto the steering wheel11, it is preferable to employ a screw method or an integral molding method which prevents the switches13a,13bfrom being easily detached from the steering wheel11. As another fixing method of the switches13a,13bto the steering wheel11, for example, it is possible to fix them in a freely detachable manner using a plane fastener.

The switches13a,13bare connected to a signal wire W2embedded inside the steering wheel11. The signal wire W2is connected to the controller14, so that an input signal produced by the switches13a,13bis transmitted to the controller14via the signal wire W2.

Upon receiving information transmitted from the information generator15, the controller14generates drive signals, used for driving the vibrators12ato12g, to the vibrators12ato12g. The controller14is connected to the information generator15and the vibrators12ato12gas well. In this connection, the information generator15may perform wireless communication with the controller14.

In the first embodiment, the controller applies a DC current (or a drive signal), which is used to drive vibration motors, configuring the vibrators12ato12g, to rotate, to the vibrators12ato12gvia the signal wire W1. The controller14generates a drive signal such that a driver can recognize vibration intensity and vibration time via his/her hands and fingers touching the vibration transmitters B1, B2. Additionally, the controller14sets a time duration to its drive signal such that the vibrators12ato12gare individually driven to vibrate for a certain time or they are sequentially driven to vibrate.

The information generator15includes a detector15athat monitors and detects the operating states of devices installed in a vehicle and a transmitter15bthat transmits information, which needs to be presented to a driver among the operating states of devices detected by the detector15a, to the controller14.

Next, the operation of the information presentation device10of the first embodiment, which is installed in a vehicle such as an automobile, will be described. Herein, the following description refers to Usage1to Usage3of the information presentation device10.

The information presentation device10of the first embodiment will be described in terms of Usage1with reference toFIGS. 1 and 2. In Usage1, the information presentation device10is installed in a vehicle in connection with the car navigation device N that guides a vehicle to its destination.

First, it is assumed that a driver drives a vehicle while holding the holding parts A1, A2of the steering wheel11with his/her both hands. A driver holding the holding parts A1, A2may as well touches the vibration transmitters B1, B2with his/her hands since the vibration transmitters B1, B2are positioned at the holding parts A1, A2of the steering wheel11.

For the sake of safety steering of a vehicle, it is not preferable for an operator to disengage his/her hands from the steering wheel11. Additionally, an operator needs to focus his/her sight and audition on driving a vehicle in order to confirm the external circumstances regarding the front view, the left/right views, and the rear view in a running direction of a vehicle.

It is possible to assume various situations in which information is presented to an operator while driving a vehicle. For example, there is a situation in which a running direction of a vehicle is presented to an operator in order to guide a vehicle to its destination in connection with the operation of the car navigation system N. The first embodiment incorporates the function of the information generator15into the car navigation system N to cope with this situation, so that the information generator15transmits information, which is used to present a running direction of a vehicle to an operator, to the controller14. For example, this information is data indicating one of two directions, i.e. leftward and rightward directions dividing a running direction of a vehicle.

The controller14selects a vibrator, which needs to be driven, from among the vibrators12ato12gin response to information presented to a driver, so that it sends a drive signal to a single vibrator12which is selected. When a leftward direction is presented to an operator as a running direction of a vehicle, for example, the controller14selects a left-side vibrator12adisposed close to the left-side holding part A1, thus sending a drive signal, which has a predetermined applied time in response to a vibrating time and an applied voltage for driving its vibration motor, to the vibrator12a. That is, a relatively intense tactile stimulus is transmitted to a driver's left hand while a relatively weak tactile stimulus is transmitted to a driver's right hand. Thus, it is possible to present a driver with information indicating a leftward direction as a direction in which a vehicle should be running.

As described above, it is possible to present a driver with information directing a running direction of a vehicle via a tactile stimulus applied to a driver's hand holding the steering wheel11as well as visual information such as a map displayed on a screen of the car navigation system N and audio information such as audio guidance. As a result, a driver is able to recognize information of the car navigation system N without turning his/her eyes away from the front direction of a vehicle.

Next, Usage2for presenting a driver with information of the car navigation system N will be described with reference toFIGS. 1 and 2.

In Usage2, the vibrators12ato12gare sequentially driven with different vibration start times applied to the vibrators12ato12gso as to present a running direction of a vehicle to a driver. In this case, the controller14receives data, indicating a running direction of a vehicle, from the car navigation system N so as to generate and send drive signals to the vibrators12ato12gsuch that their vibration start times are delayed in the order of the vibrators12a,12b,12c,12d,12e,12f, and12g.

In the above case, the vibration transmitters B1, B2transmit tactile stimuli to driver's hands holding the holding parts A1, A2of the steering wheel11such that a driver may sense a vibrating source moving in a rightward direction from the holding part A1to the holding part A2in a driver's view. Thus, it is possible to present a driver with information indicating a rightward direction as a running direction of a vehicle by way of tactile stimuli.

Contrary to the above case, when the controller14sends drive signals indicating the vibration start times which are delayed in the order of the vibrators12g,12f,12e,12d,12c,12b, and12a, the vibration transmitters B1, B2transmit tactile stimuli to driver's hands holding the holding parts A1, A2of the steering wheel11such that a driver may sense a vibrating source moving in a leftward direction from the holding part A2to the holding part A1in a driver's view. Thus, it is possible to present a driver with information indicating a leftward direction as a running direction of a vehicle by way of tactile stimuli.

Next, Usage3of the information presentation device of the first embodiment will be described with reference toFIGS. 1 to 3.FIG. 3is a block diagram of the constitution of the information presentation device10according to Usage3. Herein, Usage3differs from Usage1and Usage2in that it presents a driver with information from another device other than the car navigation device N. Herein, it presents an open/close position to a driver who operates a window W, at a driver's seat of a vehicle, to open or close by use of the switches13a,13b.

As shown inFIG. 3, the switch13ais assigned as a close switch for closing the window W while the switch13bis assigned as an open switch for opening the window W in Usage3. That is, a power window device PW is driven using the switches13a,13bto open or close the window W.

The window W is closing when a driver presses the switch13a. To the contrary, the window W is opening when a driver presses the switch13b. The window W stops its movement when a driver disengages his/her fingers from the switches13a,13b.

In the information generator15, the detector15adetects an open/close position of the window W so that the transmitter15bsends data, representing the open/close position of the window W, to the controller14.

In Usage3, the open/close position of the window W is digitized so that its opening degree increases in an order from “0” to “6”. That is, “0” is set to the fully closed state of the window W while “6” is set to the fully opened state of the window W. Among seven values “0” to “6”, one value is selectively set to data representing the open/close position of the window W.

The controller14receives data transmitted from the information generator15so as to select one of the seven vibrators12ato12g, thus sending a drive signal to the selected vibrator12. In the controller14, data values 0, 1, 2, 3, 4, 5, 6 are respectively correlated to the vibrators12a,12b,12c,12d,12e,12f,12gin turn.

The vibrator12asolely vibrating itself indicates the fully closed state of the window W whilst the vibrator12gsolely vibrating itself indicates the full opened state of the window W. The vibrator12dsolely vibrating itself indicates a half closed (or half opened) state of the window W. Additionally, the vibrator12bor12csolely vibrating itself indicates the state of the window W which is closed halfway or more but not fully closed. Moreover, the vibrator12eor12fsolely vibrating itself indicates the state of the window W which is opened halfway or more but not fully opened.

In the half opened state (or the half closed state) of the window W, for example, the information generator15selects “3” from among data values 0 to 6 so as to send it to the controller14. In response to the received data value “3”, the controller14generates a drive signal, used for driving the vibrator12dto vibrate, and send it to the vibrator12d. Thus, the vibrator12dis driven to vibrate so that its vibration propagates through the steering wheel11to reach the vibration transmitters B1, B2, from which it is transmitted to a driver's hands.

Due to vibration transmitted by the vibration transmitters B1, B2, a driver is able to sense vibration which occurs around the center of the upper arc portion of the steering wheel11. Thus, a driver is able to recognize the half opened state of the window W with his/her tactile stimuli. A driver does not need to disengage his/her hands from the steering wheel11while driving a vehicle since the steering wheel11is equipped with both the vibrators12ato12gand the switches13a,13b.

In this connection, engine vibration and running vibration of a vehicle concurrently propagate to the steering wheel11. However, human's hands have a relatively dense distribution of organoleptic cells reacting to tactile stimuli so as to exhibit a relatively high sensitivity to tactile stimuli, so that a driver is able to discriminate vibration of the vibrators12ato12gfrom normal vibration such as engine vibration and running vibration of a vehicle.

When a driver presses the switch13bso as to further open the window W which has been already opened halfway, the information generator15sequentially send data values 4, 5, 6 to the controller14, so that the controller14sends drive signals to sequentially vibrate the vibrators12e,12f,12gin response to the received data values. The controller14sets time durations to its driver signals to individually vibrate the vibrators12e,12f,12g, so that a vibrating position is changed in order among the vibrators12eto12gin connection with an open/closed position of the window W.

Due to the vibration position which is changing, a driver is able to sense an apparent movement phenomenon in which a vibrating source may move from the center of the upper arc portion of the steering wheel11toward the holding part A2. Thus, the information presentation device10transmits information, indicating an opening operation of the window W, to a driver's hands with tactile stimuli via the vibration transmitters B1, B2.

In this connection, when a driver presses the switch13ato further close the window W which has been already opened halfway, the vibrators12c,12b,12aare sequentially driven to vibrate. Thus, a driver is able to sense an apparent movement phenomenon in which a vibrating source may move from the center of the upper arc of the steering wheel11toward the holding part A1. That is, the information presentation device10transmits information, indicating a closing direction of the window W, to driver's hands with tactile stimuli via the vibration transmitters B1, B2.

The information presentation device of the first embodiment selectively drives a single vibrator to vibrate among a plurality of vibrators12ato12g, disposed along the ringed portion of the steering wheel11, thus transmitting information, generated by the information generator15, to driver's hands. Compared to the conventional art which transmits tactile stimuli to the thigh and the back of a driver, the information presentation device10of the first embodiment is able to accurately present information to a driver with weak stimulus intensity. Thus, it is possible to reduce the amount of energy consumed by the information presentation device10.

Additionally, it is possible to apply vibration of the vibrators12ato12gto a driver who is holding the holding parts A1, A2with his/her hands because the vibration transmitters B1, B2are positioned at the holding parts A1, A2of the steering wheel11. Therefore, a driver is able to sense information without disengaging his/her hands from the steering wheel11and without turning his/her eyes off from the front direction of a vehicle.

Moreover, the steering wheel11is equipped with the holding parts A1, A2at two positions while the steering wheel11is equipped with the seven vibrators12ato12gembedded therein, so that a driver is able to sense an apparent movement phenomenon in which a vibrating source may be moving when a plurality of vibrators12is sequentially driven to vibrate with time differences among their vibration start timings.

The steering wheel11is equipped with the switches13a,13bto open or close the window W, so that a driver is able to operate the window W without disengaging his/her hands from the steering wheel11. At this time, a driver is informed of an open/close position of the window W by means of the vibration transmitters B1, B2installed in the steering wheel11, so that a driver is able to sense the operating state and the open/close position of the window W without disengaging his/her hands from the steering wheel11and without turning his/her eyes to the window W.

Since the vibrators12ato12gare embedded inside the steering wheel11, a driver does not need to recognize the presence of the vibrators12ato12gunless the vibrators12ato12gare driven to vibrate even when driver's hands are touching the steering wheel11. That is, a driver does not feel a sense of incongruity with his/her hands which are currently holding certain positions, other than the holding parts A1, A2, in the steering wheel11embedding the vibrators12ato12gtherein.

Second Embodiment

Next, an information presentation device20according to a second embodiment of the present invention will be described.FIG. 4is a schematic illustration of the information presentation device20.FIG. 5is a block diagram showing the constitution of the information presentation device20.

As shown inFIGS. 4 and 5, the information presentation device20of the second embodiment differs from the information presentation device10of the first embodiment in terms of the number and the positions of vibrators as well as the positions of switches.

The first embodiment furnishes the steering wheel11with the vibrators12ato12gand the switches13a,13b. In contrast, the second embodiment furnishes a steering wheel21with vibrators22a,22band switches23a,23b.

Similar to the steering wheel11of the first embodiment, the steering wheel21has a ring-shaped external configuration, with which a vehicle is steered depending on a driver's operation. Additionally, in view of a driver who sits in front of the steering wheel21, holding parts A21, A22are formed at left and right positions in the upper side of the steering wheel21just above its center portion. The positions of the holding parts A21, A22of the steering wheel21match with ideal positions for a driver holding the steering wheel21, i.e. 10 o'clock 10 minutes of a twelve-hour clock.

Additionally, the holding parts A21, A22are furnished with vibration transmitters B21, B22that transmit vibration, propagating from the vibrators22a,22b, to a driver's hands.

The vibrators22a,22bare respectively attached to the left and right positions in the upper side of the steering wheel21just above its center portion, in view of a driver who sits in front of the steering wheel21, wherein these positions should preferably match with 10 o'clock 10 minutes of a twelve-hour clock.

Similar to the vibrators12ato12gembedded in the steering wheel11of the first embodiment, the vibrators22a,22bare embedded in the steering wheel21of the second embodiment and connected to a controller24via a signal wire W1. Similar to the vibrators12ato12gof the first embodiment, it is possible to employ vibration motors as the vibrators22a,22b.

The switches23a,23bare not entirely embedded in the steering wheel21, but as similar to the switches13a,13bof the first embodiment, the switches23a,23bare fixed to the steering wheel21such that they are projecting inwardly from the internal circumference of the ringed portion of the steering wheel21.

Additionally, the switches23a,23bare positioned at the right and left positions in the upper side of the steering wheel21just above its center portion, in view of a drive situated in front of the steering wheel21, in proximity to the vibrators22a,22b, wherein these positions should preferably match with 10 o'clock 10 minutes of a twelve-hour clock. Similar to the switches13a,13bof the first embodiment, it is possible to employ momentary switches as the switches23a,23b.

Next, the operation and the usage of the information presentation device20of the second embodiment will be described.FIG. 6is a schematic illustration illustrating the operation of the information presentation device20.

The information presentation device20of the second embodiment drives vibrators22a,22bto vary their vibration intensity so as to generate a virtual vibrating source24(i.e. virtual vibrating sources24a,24b,24c,24d,24e), thus transmitting vibration to driver's hands holding the steering wheel21. When the vibrators22a,22bare driven with the same vibration intensity, for example, a drive will be able to sense vibration of the vibrator24c, corresponding to an intermediate position between the vibrators22aand22b, with his/her hands. Alternatively, when either the vibrator22aor22bis varied in its vibration intensity so as to cause a difference of vibration intensity therebetween, a driver will be able to sense a vibrating source moving toward a vibration with higher vibration intensity.

As the vibration intensity of the vibrator22ais gradually increased to be higher than the vibration intensity of the vibrator22bin the initial condition where the vibrators22a,22bare vibrating with the same vibration intensity, a driver will be able to sense a vibrating source whose position is moving from the holding part A22to the holding part A21in the order of the virtual vibrating sources24c,24b, and24a. Contrarily, as the vibration intensity of the vibrator22bis gradually increased to be higher than the vibration intensity of the vibrator22ain the initial condition where the vibrators22a,22bare vibrating with the same vibration intensity, a driver will be able to sense a vibrating source whose position is moving from the holding part A21to the holding part A22in the order of the virtual vibrating sources24c,24d, and24e.

The information presentation device20of the second embodiment will be described in terms of Usage1.

As shown inFIG. 5, the information presentation device20of the second embodiment exhibits a directivity presentation guiding a vehicle to its destination in connection with the car navigation system N.

When the information generator15of the car navigation system N transmits information to the controller24, the controller24generates drive signals with vibration intensities selected for the vibrators22a,22b. The controller24sends drive signals to the vibrators22a,22bso as to concurrently drive the vibrators22a,22bto vibrate. This causes vibration with any one of the virtual vibrating sources24ato24e, interposed between the vibrators22a,22b, so that vibration will propagate toward the vibration transmitters B21, B22.

Next, the information presentation device20of the second embodiment will be described in terms of Usage2with reference toFIGS. 5 and 7.FIG. 7is a block diagram showing the constitution of the information presentation device20according to Usage2.

As shown inFIGS. 5 and 7, the information presentation device20using the switches23a,23bcan be used to present an open/close position of the window W at a driver's seat of a vehicle. Similar to the first embodiment, the switch23ais assigned as a close switch of the window W while the switch23bis assigned as an open switch of the window W. A driver is able to press the switch23aor23bso as to stop the window W at an appropriate position while holding the steering wheel21and gazing the front direction in driving a vehicle. At this time, the left and right vibrators22a,22bare varied in their vibration intensities depending on the open/close position of the window W.

In the second embodiment, the virtual vibrating sources24ato24ematch with discrete open/closes positions of the window W, for example, wherein a driver is able to sense the position of the virtual vibrating source24aindicating the fully closed state of the window W. A driver is able to sense the position of the virtual vibrating source24eindicating the fully opened state of the window W. A driver is able to sense the position of the virtual vibrating source24bindicating that the window W is not completely closed but is closed halfway or more. A driver is able to sense the position of the virtual vibrating source24dindicating that the window W is not completely opened but opened halfway or more.

To present a driver with the half closed state (or the half opened state) of the window W, the controller24sends drive signals to drive the vibrators22a,22bwith the same vibration intensity.

When the vibration intensity of the vibrator22ais increased to be higher than the vibration intensity of the vibrator22b, a driver will be able to sense a vibrating source whose position is close to the virtual vibrating source24arather than the virtual vibration source24c, indicating the state of the window W which is closed halfway or more. Alternatively, when the vibration intensity of the vibrator22bis increased to be higher than the vibration intensity of the vibrator22a, a driver will be able to sense a vibrating source whose position is close to the virtual vibrating source24erather than the virtual vibrating source24c, indicating the state of the window W which is opened halfway or more.

Thus, the information presentation device20of the second embodiment implements a method of presenting tactile information via driver's hands holding the steering wheel21in addition to a method of presenting visual information, displaying a map and a running direction on a display, and a method of presenting audio information using audio guidance, thus allowing a driver to adequately sense information without turning his/her eyes away from the front direction of a vehicle.

Additionally, a driver is able to sense the actual presence of a vibrating source at five positions corresponding to the virtual vibrating source24ato24ewhen the vibrators22a,22bare adequately varied in their vibration intensities. That is, it is possible to present a driver with the detailed information by using two vibrators, realizing two or more vibrating sources.

Next, variations of the information presentation device20of the second embodiment will be described.

A first variation, in which vibration transmission characteristics of the steering wheel21are measured in advance, does not cause a difference of vibration intensity between the vibrators22aand22bbut implements the controller24to supply drive signals to the vibrators22a,22bin accordance with a transmission function of vibration propagating through the steering wheel21, so that a driver will be able to sense the actual presence of a vibrating source at one position among the positions of the virtual vibrating sources24ato24e. At this time, it is possible to drive the vibrators22a,22bwith driver signals whose phases differ from each other.

According to the configuration of the first variation, a driver is able to sense a plurality of vibrating sources which is localized using two vibrators22a,22binstalled in the information presentation device20; hence, it is possible to present a driver with information using tactile stimuli.

A second variation does not drive the vibrators22a,22bin accordance with a transmission function inherently ascribed to the material of the steering wheel21but implements the controller24to supply drive signals to the vibrators22a,22brealizing the actual presence of a vibrating source at one position among the positions of the virtual vibrating sources24ato24edepending on a transmission function of an arbitrary virtual object, so that a driver will be able to sense the position of a vibrating source. At this time, it is possible to drive the vibrators22a,22bwith drive signals whose phases differ from each other.

That is, the second variation is able to transmit tactile stimuli, which may seemingly propagate through a different material than the steering wheel21and the vibration transmitters B21, B22, to a driver's hands which are touching the vibration transmitters B21, B22of the steering wheel21.

Third Embodiment

Next, an information presentation device30according to a third embodiment of the present invention will be described.FIG. 8is a schematic illustration of the information presentation device30.FIG. 9is a block diagram showing the constitution of the information presentation device30.

The information presentation device10of the first embodiment furnishes the steering wheel11with the seven vibrators12ato12g. In contrast, the information presentation device30of the third embodiment, as shown inFIGS. 8 and 9, includes a steering wheel31, eight vibrators32(i.e. vibrators32a,32b,32c,32d,32e,32f,32g, and32h), a switch33a, and a pointing device33b.

Similar to the steering wheel11of the first embodiment, the steering wheel31has a ring-shaped external configuration, wherein a steering center31ais arranged at the center of a ringed portion. In the third embodiment, the steering wheel31is furnished with holding parts A31, A32at the right and left ends thereof in a view of a vehicle's driver situated in front of the steering wheel31. Similar to the holding parts A1, A2of the first embodiment, the holding parts A31, A32of the third embodiment have a length L. Similar to the vibration transmitters B1, B2of the first embodiment, vibration transmitters B31, B32are arranged at the positions of the holding parts A31, A32of the third embodiment.

The vibrators32ato32hare embedded in the steering center31a. The vibrators32ato32hare arranged in a rectangular shape encompassing the center of the steering wheel31. Similar to the vibrators12ato12gof the first embodiment, it is possible to employ vibration motors as the vibrators32ato32h.

Similar to the switches13a,13bof the first embodiment, it is possible to employ a momentary switch as the switch33aof the third embodiment. The steering wheel31is furnished with the switch33aat the left holding part A31thereof in view of a driver situated in front of the steering wheel31. Similar to the first and second embodiments, the switch33aof the third embodiment is not entirely embedded in the steering wheel31but fixed to the steering wheel31such that it projects inwardly from the internal circumference of the ringed portion.

The pointing device33bis a joy stick which is operable in four directions, wherein the pointing device33bis able to input a desired position when it is turned down from its center position. The pointing device33bis positioned at the right holding part A32in a view of a driver situated in front of the steering wheel31.

Next, the operation and the usage of the information presentation device30of the third embodiment will be described.

A controller34selects one of the vibrators32ato32h, which needs to be driven, based on data supplied thereto from the information generator15, thus sending a drive signal to the selected vibrator.

When the controller34sends a drive signal to the vibrator32a, which is selected from among the vibrators32ato32h, the vibrator32ais driven to vibrate so that vibration thereof propagates through the steering wheel31and reaches the vibration transmitters B31, B32. Thus, vibration is transmitted to driver's hands which are touching the vibration transmitters B31, B32. At this time, the vibration transmitters B31and B32differ from each other in terms of vibration intensity because a path from the vibrator32ato the vibration transmitter B31differs from a path from the vibrator32ato the vibration transmitter B32. A driver is able to sense vibration of the vibration transmitter B31with his/her left hand while sensing vibration of the vibration transmitter B32with his/her right hand.

Next, the usage of the information presentation device30of the third embodiment will be described.

First, the information presentation device30will be described in terms of Usage1with reference toFIGS. 8 and 9. Similar to Usage1of the first embodiment, the information presentation device30cooperates with the car navigation system N to present a drive with information for guiding a vehicle to its destination.

In Usage1, the switch33ais assigned as a trigger for presenting indicating a running direction of a vehicle destined to its destination whose coordinates are set to the car navigation system N. The pointing device33bis assigned as an input device for inputting a direction of scrolling a map displayed on the screen of the car navigation system N.

The controller34sends a drive signal to the vibrators32ato32hbased on information generated by the information generator15. Herein, the position of a vehicle is indicated by the center position of a rectangular shape arranging the vibrators32ato32h, wherein the vibrator32bindicates a front direction; the vibrator32dindicates a leftward direction; the vibrator32eindicates a rightward direction; and the vibrator32gindicates a rear direction.

In order to operate the car navigation device N and scroll a map towards a destination on the display, for example, a driver needs to press the switch33awith his/her left hand so that the information generator15will transmit two-dimensional information, representing a direction toward the destination relative to the current position of a vehicle, to the controller34.

Based on two-dimensional information transmitted by the information generator15of the car navigation system N, the controller34selects one of the vibrators32ato32hand sends a drive signal to a single vibrator which needs to vibrate. In response to the drive signal, a single vibrator, selected from among the vibrators32ato32h, is driven to vibrate so that vibration propagates through the steering wheel31and reaches the vibration transmitters B31, B32, whereby vibration is transmitted to driver's hands.

Thus, it is possible to present a driver with information indicating a direction toward a destination relative to the current running direction of a vehicle. Based on tactile stimuli transmitted via the vibration transmitters B31, B32, a driver32operates the pointing device33bwith his/her right thumb so as to scroll a map toward the destination.

As another method utilizing the information presentation device30in connection with the car navigation system N, a driver may operate the pointing device33bwith his/her right hand to scroll a map and then confirm the current direction of a vehicle toward a point on the map displayed on the screen. Specifically, since the center position among the vibrators32ato32hmatches a point on a map displayed on the screen, the controller34sends drive signals to the vibrators32ato32hto vibrate based on information of the information generator15such that the vibrator32bindicates a front direction of a vehicle; the vibrator32dindicates a leftward direction of a vehicle; the vibrator32eindicates a rightward direction of a vehicle; and the vibrator32gindicates a rear direction of a vehicle.

After a driver operates the car navigation system N and operates the pointing device33bwith his/her right hand so as to scroll a map, the driver presses the switch33awith his/her left hand. In this case, the information generator15of the car navigation system N generates two-dimensional information, representing a direction toward the position of a vehicle from a point on a map displayed on the screen, and sends it to the controller34.

Based on two-dimensional information, the controller34sends a drive signal to thereby vibrate a single vibrator which is selected from among the vibrators32ato32h. Thus, a driver is able to sense the position at which one of the vibrators32ato32hvibrates. That is, it is possible to present a driver with information, representing a direction toward the position of a vehicle from a point on a map displayed on the screen, as tactile stimuli via the vibration transmitters B31, B32of the steering wheel31.

Next, the information presentation device30of the third embodiment will be described in terms of Usage2with reference toFIGS. 8 and 9.

In Usage2, the information presentation device30is connected to sensors, installed in the car navigation system N, so as to present a driver with external information of a vehicle. A distance sensor having a detection area in an external space outside the exterior surface of a vehicle can be named as one example of sensors installed in the car navigation system N. Additionally, it is possible to name a sensor that detects another vehicle or obstacles (e.g. walls, sidewalks, traffic signs, electrical poles, etc.) which may exist in the surrounding area in the lateral and rear sides of a vehicle, and a sensor that detects a preceding vehicle which may exist in the front side of a vehicle.

Since the center position among the vibrators32ato32hindicates the position of a vehicle, the controller34sends drive signals to drive the vibrators32ato32hbased on information of the information generator15so that the vibrator32bindicates the front direction of a vehicle; the vibrator32dindicates the leftward direction of a vehicle; the vibrator32eindicates the rightward direction of a vehicle; and the vibrator32gindicates the rear direction of a vehicle.

In Usage2, the foregoing sensors may transmit detection signals to the information generator15when a distance between a vehicle and its peripheral vehicle or a distance between a vehicle and an obstacle is smaller than a predetermined distance. The detector15aof the information generator15receives a detection signal from the foregoing sensor so as to determine which sensor having its detection area in a specific direction outputs the detection signal. Based on the determination result, the information generator15generates two-dimensional information, representing a direction from a vehicle to an obstacle or its peripheral vehicle, and sends it to the controller34via the transmitter15b.

Based on two-dimensional information of the information generator15, the controller34sends a drive signal to vibrate a single vibrator selected from among the vibrators32ato32h.

Thus, it is possible to present a driver with information, representing the position of an obstacle or a peripheral vehicle relative to the current position of a vehicle, as tactile stimuli. This Usage2demonstrates an effect of assisting an unskilled driver who is not good at stopping and parking a vehicle in a garage or placing it in a tandem parking manner.

In this connection, it is possible to furnish a vehicle with a sensor for detecting a relative traveling direction established between a vehicle and its peripheral vehicle. In this case, it is possible to present a driver with information, representing a relative traveling direction established between a vehicle and its peripheral vehicle other than a direction from a vehicle to an obstacle or a peripheral vehicle, by way of tactile stimuli. Additionally, it is possible to alert a driver that a peripheral vehicle is moving toward a vehicle.

Next, the information presentation device30will be described in terms of Usage3with reference toFIGS. 8 and 10.FIG. 10is a block diagram showing the constitution of the information presentation device30.

In Usage3, the information presentation device30presents a driver with external information of a vehicle in connection with sensors S1installed in a vehicle. For example, a traffic system, which installs an image sensor having sight in the front direction of a running vehicle so as to identify division lines (e.g. traffic division lanes), drawn on the opposite sides of each traffic lane, has been known. In Usage3in which the sensor S1such as an image sensor sends image information to the information generator15, the information generator15sends two-dimensional information, representing a deviating direction, to the controller34when a vehicle deviates from a traffic lane. The controller34drives the vibrators32ato32hbased on two-dimensional information transmitted from the information generator15. Herein, since the center position among the vibrators32ato32hindicates the current position of a vehicle, the controller34vibrates at least a single vibrator, selected from among the vibrators32ato32h, so as to indicate a deviating direction of a vehicle. Thus, the information presentation device30is able to alert a driver of a vehicle.

Next, the information presentation device30will be described in terms of Usage4with reference toFIGS. 8 and 10. Herein, the information presentation device30present a driver with external information of a vehicle in connection with sensors S2installed in a vehicle. For example, it presents a driver with weather conditions, such as wind speed, affecting driving by way of another method not using visual and auditory sensations. That is, a wind direction/speed sensor for detecting a wind direction and wind speed in the external environment of a vehicle is installed as the sensor S2, thus sending its detection signal to the information generator15.

The information generator15generates two-dimensional information, representing a wind direction, and sends it to the controller34when a detection signal of the wind direction/speed sensor S2indicates wind speed higher than wind speed which is determined by a driver in advance or when it indicates that wind is blowing at wind speed higher than wind speed which is determined in advance in a design stage of a vehicle as wind speed affecting a steering operation of a vehicle.

Based on two-dimensional information of the information generator15, the controller34drives and vibrates a single vibrator selected from among the vibrators32ato32h. Vibration of the selected vibrator is transmitted to driver's hands as tactile stimuli. Thus, the information presentation device30is able to present a drive with information representing a wind direction in the external environment of a vehicle.

As described above, the information presentation device30of the third embodiment demonstrates the same effect as the information presentation device10of the first embodiment.

Additionally, the information presentation device30of the third embodiment provides an easy operation for a driver to input a desired direction by use of the pointing device33b, which is coupled with the controller34and attached to the steering wheel31.

Moreover, it is possible to inform a driver of a direction from a vehicle to an obstacle or a peripheral vehicle on the center portion of the steering wheel31by way of tactile stimuli because the vibrators32ato32hare arranged in a two-dimensional manner encompassing the center of the ringed portion of the steering wheel31.

It is possible to further apply design changes to the first to third embodiments.

As the information which the information presentation devices10,20,30present to a driver of a vehicle, it is possible to employ running condition variations due to a driving operation of a vehicle. For example, it is possible to provide information indicating an operating condition of a vehicle, information informing a driver of a hazard against a vehicle, and information informing a driver of an external condition of a vehicle. Specifically, it is possible to provide information indicating occurrence of a trouble or failure in a vehicle, information indicating the presence of another vehicle approaching a vehicle from its external area, information indicating weather (e.g. a wind direction and wind speed) external to a vehicle, and guidance information indicating a running speed by way of the car navigation system N. In this connection, the information which the information generator15sends to the controllers14,24,34is not necessarily limited to the foregoing information.

The first to third embodiments employ a steering wheel having a ring-shaped external configuration, but the shape of a steering wheel is not limited to this configuration; hence, it is possible to employ a steering wheel having a rectangular shape. Additionally, the information presentation devices10,20,30according to the first to third embodiments can be applied to a lever instead of a steering wheel. In this case, it is possible to demonstrate the same effect described above.

Additionally, it is possible to reshape a holding part of a steering wheel such that a vibration transmitter projects from the external surface of a steering wheel, thus achieving a close contact state between the vibration transmitter and a driver's hand. That is, it is possible to appropriately shape a vibration transmitter to an extent that the vibration transmitter will not cause a sense of incongruity and inconvenience for a driver who is operating a steering wheel.

The first to third embodiments employ vibration motors as vibrators; but this is not a restriction. As vibrators, for example, it is possible to employ piezoelectric vibrators; alternatively, it is possible to use other materials for vibrators.

The first to third embodiments employ momentary switches as switches; but this is not a restriction. As switches, for example, it is possible to employ micro switches, slide switches, or pressure switches; or alternatively, it is possible to use other materials for switches.

The information presentation device20of the second embodiment realizes five virtual vibrating sources24ato24eby use of two vibrators22a,22b, wherein it is possible to change vibration intensity ratios to drive signals input to the vibrators22a,22bin response to a threshold of human's audio perception, thus appropriately increase or decrease the number of virtual vibrating sources.

The information presentation device30of the third embodiment includes the pointing device33bcapable of inputting four directions, wherein it is possible to appropriately increase or decrease the number of inputted directions. For example, it is possible to employ a pointing device which is able to input eight directions.

Additionally, the information presentation device30of the third embodiment arranges the switch33aon the left-hand side of a driver while arranging the pointing device33bon the right-hand side of a driver, wherein it is possible to reverse the positional relationship between them. That is, it is possible to arrange the pointing device33bon the left-hand side of a driver while arranging the switch33aon the right-hand side of a driver.

The first to third embodiments are not necessarily limited in terms of the number of vibrators; hence, it is possible to appropriately increase or decrease the number of vibrators.

Additionally, it is possible to appropriately combine the constituent elements described in conjunction with the first to third embodiments and their variations. For example, the third embodiment may be reconfigured in a similar manner as the first embodiment, wherein a plurality of vibrators is selected from among the vibrators32ato32hso that the selected vibrators are sequentially driven with a time different applied to their vibration start timings. In this case, it is possible to present directive information indicative of the direction of a vehicle which a driver is able to sense by intuition.

Fourth Embodiment

Next, an information presentation device according to a fourth embodiment of the present invention will be described with reference toFIGS. 4,5, and11.

FIG. 11includes graphs showing control waveforms generated by an information presentation device40of the fourth embodiment, wherein the horizontal axis represents time while the vertical axis represents amplitude. The information presentation device40arranges a vibrator42aon the left-hand side and a vibrator42bon the right-hand side in view of a driver situated in front of the steering wheel21.FIG. 11(A)shows a control waveform102of the vibrator42apositioned on the left-hand side of the steering wheel21, whileFIG. 11(B)shows a control waveform112of the vibrator42bpositioned on the right-hand side of the steering wheel21.

The external configuration of the information presentation device40of the fourth embodiment is identical to that of the information presentation device20of the second embodiment (seeFIG. 4). As shown inFIG. 5, the information presentation device40includes the vibrators42a,42binstead of the vibrators22a,22bas well as a controller44instead of the controller24.

The information presentation device40includes the vibrators42,42bwhich include piezoelectric vibrators. Using piezoelectric vibrators, the information presentation device40is able to control vibration frequencies in addition to vibration intensity with the vibrators42a,42b.

In general, it is known that humans are able to perceive vibration frequencies, ranging from 150 Hz to 200 Hz. When eccentric motors are used as the vibrators42a,42b, however, the vibration intensity of the vibrators42a,42bdepends on the rotation speed of eccentric motors with the same amount of eccentricity. For this reason, it may not be possible to set the vibration frequency of the vibrators42a,42bto the perceptible vibration frequency even when the vibration intensity is controlled to match a desired intensity. Contrarily, when the vibrators42a,42binclude piezoelectric vibrators which can be easily controlled in the vibration intensity and the vibration frequency independently, it is possible to easily control the vibration intensity of the vibrators42a,42bat a desired value while confining the vibration frequency of the vibrators42a,42bwithin the perceptible vibration frequency.

As shown inFIG. 5, the controller44is connected to the vibrators42a,42b. The controller44of the fourth embodiment differs from the controller24of the second embodiment in that it is able to control the vibrators42a,42bso as to cause an apparent movement phenomenon sensed by a driver who is holding the steering wheel21with the holding parts A21, A22. That is, the controller44generates control waveforms causing a vibrating source which moves in left-right directions in view of a driver situated in front of the steering wheel21.

To present a driver with sensation as if a vibrating source moves from the left to the right in view of a driver situated in front of the steering wheel21, for example, the controller44starts the vibrator42ato vibrate at time TL(seeFIG. 11(A)) and then starts the vibrator42bto vibrate at time TRwhich is delayed from time TLby a certain time interval ΔT (seeFIG. 11(B)). That is, the controller44generates the control waveform102causing the vibrator42ato vibrate and the control waveform112causing the vibrator42bto vibrate, thus generating vibration with a phase shift corresponding to the time interval ΔT.

The controller44generates the control waveform102which causes the vibrator42ato start vibration at time TL, gradually increases its amplitude, and then gradually decreases its amplitude, thus stopping the vibrator42ato vibrate. Similarly, the controller44generates the control waveform112which causes the vibrator42bto start vibration at time TR, gradually increases its amplitude, and then gradually decreases its amplitude, thus stopping the vibrator42bfrom vibrating.

After the controller44starts the vibrator42ato vibrate in accordance with the control waveform102, the vibrator42agradually increases its vibration intensity while the control waveform102is increased in amplitude. At this time, the controller44causes a driver, who senses vibration of the vibrator42a, to feel as if a vibrating source will be approaching the vibrator42a. The vibrator42agradually decreases its vibration intensity while the control waveform102is decreased in amplitude. At this time, the controller44causes a driver, who senses vibration of the vibrator42a, to feel as if a vibrating source is leaving off from the vibrator42a.

After the controller44starts the vibrator42bto vibrate in accordance with the control waveform112, the vibrator42bgradually increases its vibration intensity while the control waveform112is increased in amplitude. At this time, the controller44causes a driver, who senses vibration of the vibrator42b, to feel as if a vibrating source is approaching the vibrator42b. The vibrator42bgradually decreases in vibration intensity while the control waveform112is decreased in amplitude. At this time, the controller causes a driver, who senses vibration of the vibrator42b, to feel as if a vibrating source is leaving off from the vibrator42b.

When the vibrators42a,42bvibrate in accordance with the control waveforms102,112, a driver may feel as if a vibrating source is approaching the vibrator42adue to a phase difference corresponding to the time interval ΔT between the control waveforms102,112, and then the vibrating source is moving toward the vibrator42bafter the time interval ΔT elapses from time TL. The fourth embodiment is able to present a driver with a sensation as if a vibrating source is moving until the control waveforms102,112are terminated in amplitude after they start to increase in amplitude.

Contrarily, to present a driver with a sensation as if a vibrating source is moving from the right to the left in a driver's view, the controller44firstly starts the vibrator42bto vibrate and then starts the vibrator42ato vibrate with a delay of the time interval ΔT.

The controller44generates the control waveforms102,112, causing the vibrators42a,42bto vibrate, in accordance with Equation 1 and Equation 2.

Equation 1 represents the control waveform102of the vibrator42a(seeFIG. 11(A)) positioned on the left-hand side in a driver's view, while Equation 2 represents the control waveform112of the vibrator42b(seeFIG. 11(B)) positioned on the right-hand side in a driver's view. The control waveforms102,112are expressed as functions AL(t), AR(t) which vary with respect to time.

The control waveform102expressed in Equation 1 is a waveform modulating the amplitude of a carrier wave, i.e. a sine wave with frequency f and amplitude A, with a modulation wave101expressed as sin(2πfm(T−TL)). The control waveform112expressed in Equation 2 is a waveform modulating the amplitude of a carrier wave, i.e. a sine wave with frequency f and amplitude A, with a modulation wave111expressed as sin(2πfm(T−TR)). Equations 1, 2 include fm representing the number of times in repeating the modulation waves101,111in a unit time, i.e. the number of repetition times per one second in the fourth embodiment. In this connection, the fourth embodiment sets frequency f of 150 Hz to the control waveforms102and112.

The controller44generates the modulation waves101,111have chevron waveforms which are started at time TL, TR, wherein a time until a vibrating source stops moving after it starts moving is represented using a time until the modulation waves101,111are terminated in amplitude after they start to increase in amplitude.

The modulation waves101and111are each regarded as a half-period waveform corresponding to a sine wave with a low frequency, e.g. 0.5 Hz. This allows a driver to sense one second as a period of time until a vibrating source stops moving after it starts moving. Since a sine wave has a low frequency of 0.5 Hz which is lower than human's perceptible vibration frequency, it is difficult for a driver to sense vibration by use of tactile stimuli solely depending on the modulation waves101,111each configured of a half-period waveform corresponding to a sine wave of 0.5 Hz. For this reason, amplitude modulation is performed according to Equations 1, 2 such that the modulation waves101,111are each multiplied by a sine wave with the frequency f. In this connection, the fourth embodiment involves the setting where TL<TR, ΔT=0.2 seconds.

The vibrators42a,42bare driven to vibrate in response to the control waveforms102,112, which are varied in amplitude with respect to time t according to Equations 1, 2, input thereto from the controller44.

As described above, the controller44modulates the amplitudes of the modulation waves101,111, which allow a driver to sense an apparent movement phenomenon, by use of a carrier wave with a perceptible vibration frequency, thus producing the control waveforms102,112, whereby it supplies the control waveforms102,112to the vibrators42a,42b, thus driving the vibrators42a,42bto vibrate. In the information presentation device40of the fourth embodiment, the controller44individually drives the vibrators42a,42bto vibrate so as to transmit vibration of modulation waves to a driver, thus presenting a driver with a sensation as if a vibrating source is moving in left-right directions on the steering wheel21.

The fourth embodiment adopts the setting in which the modulation waves101,111have frequency fm of 0.5 Hz; the control waveforms102,112have frequency f of 150 Hz; and a time interval between the vibrator42astarting its vibration and the vibrator42bstarting its vibration is set to 0.2 seconds; but they are not necessarily limited to these values. That is, it is possible to appropriately change the frequency and the time interval regarding a control waveform driving a vibrator in such a way that a driver may easily sense vibration as tactile stimuli.

Additionally, the fourth embodiment defines the control waveforms102,112according to Equations 1, 2; but the control waveforms102,112are not necessarily limited to Equations 1, 2. For example, the value of amplitude A in Equations 1, 2 is not necessarily set to the same value with respect to both the control waveforms102,112.

In the fourth embodiment, the controller44may repeat the control waveforms102,112, with the foregoing phase difference, multiple times. That is, it is possible to repeat the control waveform102with one period corresponding to a period of time ranging from time TLto time TL+½fm, while it is possible to repeat the control waveform112with one period corresponding to a period of time ranging from time TRto time TR+½fm. Alternatively, it is possible to repeat each of the control waveforms102,112with one period corresponding to a period of time ranging from time TLto time TR+½fm. Except for these settings, it is possible to repeat the control waveform102,112, with a certain time interval or an arbitrary time interval therebetween, multiple times.

Although the fourth embodiment employs piezoelectric vibrators as the vibrators42a,42b, it is possible to employ voice coil motors (VCM) as vibrators which can be controlled in frequency and vibration intensity independently. As devices used for the vibrators42a,42bother than piezoelectric vibrators and VCM, it is possible to appropriately employ any other devices which can be controlled in frequency and vibration intensity independently.

Fifth Embodiment

Next, an information presentation device50according to a fifth embodiment of the present invention will be described with reference toFIGS. 4,5, and12.

The information presentation device50of the fifth embodiment is designed such that a controller54controls the vibrators42a,42battached to the steering wheel21.FIG. 12includes graphs showing control waveforms which the controller54of the information presentation device50generates to drive the vibrators42a,42bto vibrate, wherein the horizontal axis represents time while the vertical axis represents amplitude. That is,FIG. 12(A)shows a control waveform for driving the vibrator42a, whileFIG. 12(B)shows a control waveform for driving the vibrator42b.

The external configuration of the information presentation device50of the fifth embodiment is identical to that of the information presentation device20of the second embodiment, whereas it includes the vibrators42a,42binstead of the vibrators22a,22band the controller54instead of the controller24. The controller54of the fifth embodiment differs from the controller24of the second embodiment and the controller44of the fourth embodiment in that it presents a driver with a sensation as if a vibrating source is moving in a discrete manner.

The phrase “a sensation as if a vibrating source is moving in a discrete manner” conveys the meaning of presenting a driver with tactile stimuli as if the virtual vibrating sources24a,24b,24c,24d, and24e, which are mutually separated from each other as shown inFIG. 6, may actually exist by means of the vibrators42a,42b. For example, it is possible to present a driver with a sensation as if a vibrating source is sequentially moving toward positions with spacing of a predetermined distance by way of a sequence in which after a driver senses the virtual vibrating source24aas an actual vibrating source, the virtual vibrating source24astops vibrating, thereafter, a driver senses the virtual vibrating source24bas an actual vibrating source.

The controller54generates control waveforms to sequentially drive the virtual vibrating sources24a,24b,24c,24d, and24ewithin the distance between the vibrators42a,42b, thus presenting a driver with a sensation in which a vibrating source is moving in a discrete manner in their order.

Compared with the controller24of the second embodiment which changes a ratio of vibration intensity between the vibrators22a,22b, the controller54of the fourth embodiment produces and changes a time difference between the timings at which the vibrators42a,42bstart to vibrate.

The operation for presenting a driver with a sensation as if a vibrating source is moving in a discrete manner from the virtual vibrating source24ato the virtual vibrating source24ewill be described. First, the controller54sends a rectangular wave with amplitude A1L(seeFIG. 12(A)) to the vibrator42ain order to render a driver feeling a sensation as if a vibrating source is localized at the virtual vibrating source24a. Additionally, it sends a rectangular wave with amplitude A1R(see FIG.12(B)), which is smaller than amplitude A1L, to the vibrator42bat a timing delayed from the rectangular wave of amplitude A1Lby a time interval ΔT1.

Next, the controller54sends a rectangular wave with amplitude A2L(see FIG.12(A)), which is smaller than amplitude A1L, to the vibrator42ain order to render a driver feeling a sensation that a vibrating source has been changed in position from the virtual vibrating source42ato the virtual vibrating source24b. Additionally, it sends a rectangular wave with amplitude A2R, which is smaller than amplitude A2Lbut larger than amplitude A1R, to the vibrator42bat a timing delayed from the rectangular wave of amplitude A2Lby a time interval ΔT2. In this connection, the time interval ΔT2is shorter than the time interval ΔT1. Compared to the situation in which the vibrators42a,42bare driven to vibrate such that a vibrating source is localized at the virtual vibrating source24a, it is possible to decrease the vibration intensity of the vibrator42abut to increase the vibration intensity of the vibrator42bwhile reducing a time interval between the timing of a driver sensing vibration of the vibrator42aand the timing of a driver sensing vibration of the vibrator42b, thus causing a driver to feel a sensation as if a vibrating source is moving from the virtual vibrating source24ato the virtual vibrating source24b.

Thus, the controller54decreases the amplitude of the vibrator42ain a stepwise manner while delaying the vibration start timing of the vibrator42ain a stepwise manner as a vibrating source is moving in a direction of aligning the virtual vibrating sources24a,24b,24c,24d, and24e(i.e. a direction from the vibrator42ato the vibrator42b). Additionally, the controller54increases the vibrating amplitude of the vibrator42bin a stepwise manner while advancing the vibration start timing of the vibrator42bin a stepwise manner.

As shown inFIG. 12, the controller54of the fifth embodiment subdivides a time period into times T1to T5with a time interval of 0.25 seconds therebetween in correspondence with the virtual vibrating sources24ato24e. As shown inFIG. 12(A), the controller54produces rectangular waves to advance or delay the vibration start timing of the vibrator42arelative to each time. As shown inFIG. 12(B), it sets time intervals ΔT1to ΔT5between the vibration start timing of the vibrator42aand the vibration start timing of the vibrator42as follows.

As described above, the controller54of the fifth embodiment controls the vibrators42a,42bto vibrate multiple times with a time difference between the vibration start timing of the vibrator42aand the vibration start timing of the vibrator42b. Additionally, the controller54gradually decreases the time difference between the vibration start timing of the vibrator42aand the vibration start timing of the vibrator42b.

Moreover, the time difference of zero seconds is set between the vibration start timings of the vibrators42aand42bat the virtual vibrating source24ccorresponding to the center position between the vibrators42aand42b. The controller54increases a time difference between vibration start timings as a vibrating source approaches the vibrator42aor the vibrator42b.

The fifth embodiment is able to render a driver feeling a sensation that a vibrating source is moving in a discrete manner because the controller54controls the vibration start timings of the vibrators42a,42bin addition to the vibration intensity of the vibrators42a,42b. That is, it is possible to render a driver feeling a sensation as if a vibrating source is actually vibrating while being localized at each of the virtual vibrating sources24ato24ewith a good accuracy.

InFIG. 12, the controller54drives the vibrators42a,42bto consecutively vibrate five times; however, it is possible to drive the vibrators42a,42bto vibrate five times with different time intervals. The number of times regarding the occurrence of vibration with the vibrators42a,42bis not necessarily limited to five times, wherein two or more times may suffice the need to render a driver feeling a sensation as if a vibrating source is moving; hence, it is unnecessary to limit the number of times causing vibration. Additionally, it is possible to solely change the vibration start timing without changing the vibration intensity of the vibrators42a,42b. Thus, it is possible to render a driver feeling a sensation as if a vibrating source is moving in left-right directions. Moreover, it is unnecessary to the vibration start timing and the amplitude of rectangular waves to the foregoing values when generating control waveforms driving the vibrators42a,42b.

Sixth Embodiment

Next, an information presentation device according to a sixth embodiment of the present invention will be described with reference toFIGS. 4,5, and13. The information presentation device60of the sixth embodiment is designed such that a controller64controls the vibrators42a,42battached to the steering wheel21.FIG. 13includes graphs showing control waveforms which the controller64produces in order to drive the vibrators42a,42b, wherein the horizontal axis represents time while the vertical axis represents amplitude.

The controller64of the sixth embodiment controls the vibrators42a,42bto render a driver feeling a sensation as if a vibrating source is moving in upward-downward directions, perpendicular to a line segment drawn between the two vibrators42aand42b, in a view of a driver situated in front of the steering wheel21. As shown inFIG. 13, the controller64produces a control waveform103, multiplying a modulation wave101by a carrier wave corresponding to a sine wave with human's perceptive vibration frequency. The control waveform103of the sixth embodiment differs from the control waveform102of the fourth embodiment in that it may change its frequency.

The controller64produces the control waveform having a waveform whose frequency is monotonously decreasing. As shown inFIG. 13, the controller64performs frequency sweep in such a way that a relatively high frequency ft1is set to a vibration starting stage while a relatively low frequency ft2is set to a vibration terminating stage. The controller64produces the control waveform103expressed in Equation 3.
A(t)=Asin(2πfmt)·sin(2πf(t)t)
f(t)=−at+b[Equation 3]

In Equation 3, f(t) denotes a function defining the frequency of a sine wave which is multiplied by the modulation wave101. According to Equation 3 when a=450 Hz, b=500 Hz, the controller64produces the control waveform103whose frequency is swept from 500 Hz to 50 Hz by way of a function A(t). In this connection, it is not necessary to perform frequency sweep in an order from a high frequency to a low frequency, but it is possible to perform frequency sweep in an order from a low frequency to a high frequency.

The sixth embodiment is able to render a driver feeling a sensation, via tactile stimuli, as if a vibrating source is moving from a high position to a low position or as if a vibrating source is moving from a low position to a high position because the controller64vibrates the vibrators42a,42bin response to the control waveform103subjected to frequency sweep in a lapse of time.

Although the sixth embodiment employs a single control waveform shown inFIG. 13in order to render a driver feeling a sensation as if a vibrating source is moving in upward-downward directions, it is possible to combine the control waveform with the foregoing control waveform, as described in the fourth embodiment, which causes a driver to feel a sensation as if a vibrating source is moving in left-right directions. That is, it is possible to multiplex the control waveform shown inFIG. 13with the control waveform of the fourth embodiment involving a certain time interval, thus causing a driver to feel a sensation as if a vibrating source is moving in slanted directions combining upward-downward directions with left-right directions.

Additionally, the information presentation device60of the sixth embodiment can be modified to render a driver feeling a sensation as if a vibrating source is moving two-dimensionally on a two-dimensional plane combining upward-downward directions with left-right directions. For example, it is possible to render a driver feeling a sensation as if a vibrating source is moving along a virtual circumference on a two-dimensional plane or a sensation as if a vibrating source is looping back in its moving direction while turning its running direction on a two-dimensional plane.

Alternatively, it is possible to independently drive the two vibrators42a,42b. By independently driving the vibrators42a,42b, it is possible to realize a vibrating source which is able to move in upward-downward directions on the right side or in upward-downward directions on the left side, thus presenting a driver with information differently on the right side and on the left side.

In the sixth embodiment, the modulation wave101has a period of one second while the control waveform103is subjected to frequency sweep from 500 Hz to 50 Hz; but they are not necessarily limited to these values. Additionally, the controller64does not necessarily employ Equation 3 as an equation for calculating the control waveform103.

Seventh Embodiment

Next, an information presentation device70according to a seventh embodiment of the present invention will be described with reference toFIGS. 4,5, and14. The information presentation device70of the seventh embodiment is designed such that a controller74controls the vibrators42a,42battached to the steering wheel21.FIGS. 14(A), (B), and (C) show control waveforms generated by the controller75. Herein, the upper graphs inFIGS. 14(A), (B), (C) show frequency components included in control waveforms, wherein the horizontal axis represents frequency while the vertical axis represents amplitude. The lower graphs inFIGS. 14(A), (B), (C) show superposition of waveforms having different frequencies, wherein the horizontal axis represents time while the vertical axis represents amplitude.

In this connection, the controller74of the seventh embodiment operates differently in comparison with the controller64of the sixth embodiment, wherein the seventh embodiment operates similar to the sixth embodiment to render a driver feeling a sensation as if a vibrating source is moving in upward-downward directions.

The controller64of the sixth embodiment produces the control waveform103subjected to frequency sweep over time, thus causing a driver to feel a sensation as if a vibrating source is moving in upward-downward directions. Contrarily, the controller74of the seventh embodiment superimposes sine waves having different frequencies so as to produce a control waveform. The controller74produces a control waveform as defined in Equation 4. In this connection, Equation 4 superimposes sine waves with frequency fi (where i=1 to 5).

The controller74combines sine waves with five frequencies f1to f5, ranging from a low frequency to a high frequency, according to Equation 4, and then performs amplitude modulation using the modulation wave101, thus producing a control waveform.

As shown inFIG. 14(A), the controller74produces a control waveform including plenty of low frequency components, among sine waves of frequencies f1to f5, at a vibration start time t=0.0 second. Additionally, it produces a control waveform including plenty of high frequency components, among sine waves of frequencies f1to f5, at time t=tx (e.g. tx=0.1 seconds).

In the seventh embodiment, the controller74adopts five frequencies, i.e. f1=100 Hz, f2=200 Hz, f3=300 Hz, f4=400 Hz, and f5=500 Hz, as frequencies of sine waves forming control waveforms generated therein. At the vibration start time t=0.0 seconds shown inFIG. 14(A), a control waveform is formed by way of superimposition of sine waves having relatively low frequencies, i.e. f1=100 Hz and f2=200 Hz, wherein an amplitude Af100of a sine wave f1is larger than an amplitude Af200of a sine wave f2.

The controller74changes a ratio of mixing frequency components over time. Additionally, it gradually decreases the mixing ratio of low frequency components over time as shown inFIGS. 14(B), (C) after it starts presenting a driver with information via vibration. At time t=0.5 seconds shown inFIG. 14(B), an amplitude Af300of a sine wave f3is the highest amplitude while frequency components lower than or higher than the frequency f3are reduced in amplitude. At time t=1.0 second shown inFIG. 14(C), a control waveform is formed using sine waves f4and f5having relatively high frequencies, wherein an amplitude Af500of the sine wave f5is larger than an amplitude Af400of the sine wave f4.

Thus, the controller74changes its mixing ratio of frequency components over time so as to drive the vibrators42a,42bwith control waveforms which are shifted from low frequency components to high frequency components. Thus, it is possible to render a driver feeling a sensation as if a vibrating source is moving from a downward direction to an upward direction in view of a driver situated in front of the steering wheel21.

Contrary to the above, the controller74changes its mixing ratio of frequency components over time so as to drive the vibrators42a,42bwith control waveforms which are shifted from high frequency components to low frequency components. In this case, it is possible to render a driver feeling a sensation as if a vibrating source is moving from an upward direction to a downward direction in view of a driver situated in front of the steering wheel21.

Additionally, it is possible to combine a control waveform of the seventh embodiment, causing a driver to feel a sensation as if a vibrating source is moving in upward-downward directions, and a control waveform of the fourth embodiment, causing a driver to feel a sensation as if a vibrating source is moving in left-right directions. Thus, it is possible to render a driver feeling a sensation as if a vibrating source is moving in a slanted direction, a circumferential direction, and a loop-back direction on a two-dimensional plane in view of a driver situated in front of the steering wheel21.

The seventh embodiment forms control waveforms each combining the modulation wave101with sine waves having five frequencies, i.e. f1=100 Hz, f2=200 Hz, f3=300 Hz, f4=400 Hz, and f5=500 Hz, with a predetermined mixing ratio; but sine waves forming control waveforms are not necessarily limited to five types of frequencies. Additionally, the mixing ratio of sine waves having different frequencies is not necessarily limited to the foregoing value.

Moreover, an equation defining a control waveform generated by the controller74is not necessarily limited to Equation 4, wherein frequency components forming control waveforms are not necessarily limited to five types of frequencies. It is possible to analogously determine a mixing ratio of sine waves forming control waveforms, thus generating control waveform having a plurality of vibration frequencies by way of inverse frequency conversion. For example, it is possible to set a sequentially varying frequency spectrum, which is subjected to inverse Fourier transform to generate a control waveform.

Eighth Embodiment

Next, an information presentation device80according to an eight embodiment of the present invention will be described with reference toFIGS. 4,5, and15. The information presentation device80of the eighth embodiment is designed such that a controller84controls the vibrators42a,42battached to the steering wheel21.FIG. 15shows a control waveform105generated by the controller84, wherein the horizontal axis represents time while the vertical axis represents amplitude.

In the eighth embodiment, the controller84drives the vibrators42a,42bin accordance with the control waveform105so as to render a driver feeling a sensation as if a vibrating source is moving in near-far directions in the front direction in view of a driver situated in front of the steering wheel21.

To render a driver feeling a sensation as if a vibrating source is moving in near-far directions, the controller84produces the control waveform105simulating Doppler effect, thus driving the vibrators42a,42bto vibrate in accordance with the control waveform105.

That is, the controller84produces the control waveform105representing an amplitude-modulated wave multiplying the modulation wave101by a sine wave of a human's perceptible vibration frequency. Additionally, a vibrating source is assumed to be localized at an intermediate point, which is determined in near-far directions in the front direction of a driver, at a boundary time tc, wherein the control waveform105is changed in frequency in a former part TAand a latter part TBbefore and after the boundary time tc.

Specifically, in order to realize an observation that a vibrating source is approaching a driver with the former part of the control waveform105, the controller84produces the control waveform105multiplying the modulation wave101by a carrier wave in which the frequency of the former part TAbecomes higher than the frequency of the latter part TBwith respect to the boundary time tc or a carrier wave in which the frequency of the latter part TBbecomes lower than the frequency of the former part TA.

Equation 5 represents the control waveform105involving a carrier wave whose frequency is changed over at time tc. Herein, fa≠fb.

According to Equation 5, the controller84produces the control waveform105whose frequency is changed from the frequency fa to the frequency fb at the boundary time t=tc. That is, the controller84produces the control waveform105, simulating the Doppler effect, causing a driver to feel a sensation as if a vibrating source is reversing its traveling direction relative to a driver before and after time t=tc.

When the lower column of Equation 5 adopts fa=300 Hz and fb=50 Hz, for example, it is possible to cause a drive to feel a sensation as if a vibrating source temporarily approaches to a driver and then departs from a driver. Alternatively, when fa=50 Hz and fb=300 Hz, it is possible to realize the reverse of the traveling direction in which a vibrating source travels relative to a driver.

When the frequency is changed at time t=tc while the vibration of the vibrators42a,42bis transmitted as tactile stimuli, it is possible to render a driver feeling a sensation as if a vibrating source moves toward a driver from his/her far side and then departs from the driver or a sensation as if a vibrating source temporarily departs from a driver and then approaches the driver.

Thus, as described in Usage2of the third embodiment, it is possible to present a driver with relative movement information between a vehicle and a peripheral vehicle because the information presentation device80of the eighth embodiment is able to render a driver feeling a sensation as if a vibrating source is traveling in far-near directions.

With the control waveform105generated by the controller84of the eighth embodiment, it is possible to render a driver feeling a sensation as if a vibrating source is moving in upward-downward directions. The control waveform of the eighth embodiment can be combined with the foregoing control waveforms of the other embodiments. Thus, it is possible to render a driver feeling a sensation as if a vibrating source is moving in far-near directions relative to a driver in addition to a sensation as if a vibrating source is moving in a slanted direction, a circumferential direction, or a loop-back direction on a two-dimensional plane in a driver's view.

The eighth embodiment produces the control waveform105combining the modulation wave101, described in the fourth embodiment, with a carrier wave of 50 Hz or 300 Hz and sets a frequency switching time tc=0.5 seconds to the control waveform105; however, they are not necessarily limited to these values.

As described heretofore, information presentation devices of the present invention are described by way of the first to eighth embodiments with reference to the accompanying drawings; however, the constitution and the operation of the present invention are not necessarily limited to the embodiments, and therefore the present invention may embrace any design choices within the scope of the invention defined in the appended claims.

For example, the fourth embodiment adopts half-period waveforms of sine waves as the modulation waves101,111; however, modulation waves are not necessarily limited to these waveforms. As the modulation waves101,111, for example, it is possible to employ a triangular wave whose amplitude increases at a constant rate and then decreases at a constant rate. At this time, it is possible to appropriately determine a rate for increasing amplitude and a rate for decreasing amplitude; for example, it is possible to employ a sawtooth wave as a modulation wave.

INDUSTRIAL APPLICABILITY

The information presentation device of the present invention is installed in a vehicle such as an automobile and designed to present various types of information via vibration applied to driver's hands, wherein it is possible to present information, representing the running condition of a vehicle, and external environmental information without causing a driver turning his/her eyes off from the front side in the running direction of a vehicle. Additionally, the information presentation device of the present invention can be installed in any type of machines other than vehicles, for example, wherein it is possible to present various types of information via vibration applied to operators who operate displays such as information terminals, game devices, and virtual reality devices.

REFERENCE SIGNS LIST