Patent Description:
In recent years, a pen-type position indicating device (hereinafter referred to as an "electronic pen") that is used in combination with a tablet-type computer has attracted attention. This type of electronic pen is usually provided with a pen pressure sensor that detects a pressure (pen pressure) applied to a pen tip. When the computer detects the position of the electronic pen in a touch surface, the computer receives a pen pressure value from the electronic pen. Then, when the computer draws a line image according to the detected position, the computer controls a line width and transparency of the line image according to the received pen pressure value. This configuration can produce the feel of writing similar to that of an existing pen that ejects ink, for example, draw a thicker line as the force with which the pen tip is pressed against the touch surface is greater.

Further, Patent Document <NUM> discloses a pen-type input device that does not require a touch surface. This pen-type input device includes a pressure sensor on its side surface and is capable of detecting a gripping force of the user. According to the view of Patent Document <NUM>, when the user draws a character or a figure by holding a pen, a characteristic corresponding to the character or the figure to be drawn appears in a change in the gripping force. The technique of Patent Document <NUM> recognizes this characteristic as the character or the figure, thereby enabling an input of the character or the figure without detecting the position of a pen tip in the touch surface.

<CIT> discloses a method for communication between a host processor and an active stylus via a sensor controller, wherein the sensor controller is coupled to a sensor configured to interact with the active stylus.

<CIT> discloses detection of a stylus at a large distance from a surface of a device, such as a tablet, by increasing the stylus' transmitted signal strength.

<CIT> discloses a multi-touch orientation sensing input device including a device body that is partially enclosed or completely enclosed by a multi-touch sensor.

<CIT> discloses systems and methods for optical transmission of haptic display parameters.

<CIT> and <CIT> disclose styli usable for three-dimensional input in a virtual reality space.

Incidentally, the inventors of the present application consider how to make it possible to write a character and draw a picture on a virtual plane in a virtual reality (including VR: Virtual Reality, AR: Augmented Reality, and MR: Mixed Reality) space using the electronic pen described above. In this case, since there is no actual touch surface, the pen pressure value cannot be detected by the above-described pen pressure sensor. Without the pen pressure value, it is not possible to control the line width and the transparency according to the pen pressure value, and therefore, it is not possible to produce the feel of writing similar to that of an existing pen. Accordingly, there has been a need for another method that can control the line width and the transparency in a preferable manner.

Therefore, one of objects of the present invention is to provide a position indicating device and an information processing device capable of controlling the line width and the transparency in a preferable manner even when there is no actual touch surface.

A position indicating device according to the present invention includes a housing, a position indicating portion configured to indicate a position, a first sensor configured to detect a first pressure applied to the position indicating portion, a second sensor configured to detect a second pressure applied to the housing, a first communication unit configured to transmit a data signal including the first pressure detected by the first sensor to a first device for applying the first pressure to the position indicating portion, wherein the first device is a position sensor including an input surface and a plurality of electrodes arranged so as to cover the input surface, wherein the first communication unit is configured to transmit the data signal such that the first device can receive the data signal by using the plurality of electrodes, and a second communication unit configured to transmit the second pressure detected by the second sensor to a second device for controlling generation of a three-dimensiona object in a virtual reality space.

It is noted that the position indicating device according to the present invention may be a position indicating device including a cylindrical external housing accommodating a position indicating portion for indicating a position in an input surface of a plane position sensor, a spatial position detection unit configured to detect spatial position information for indicating a position of the position indicating device in a space through interaction with an external device, a pressure sensor configured to detect a force on the external housing, and a processing unit configured to output the spatial position information detected by the spatial position detection unit, plane position information for indicating the position of the position indicating portion in the input surface, and pressure information regarding the force detected by the pressure sensor.

When the user writes a character or draws a picture on a virtual plane, a force (=gripping force) detected by a pressure sensor has a certain correlation relation with a pen pressure detected when the user writes a character or draws a picture on an actual touch surface. Therefore, the position indicating device according to the present invention capable of transmitting a pressure detected by a pressure sensor and the information processing device according to the present invention capable of performing 3D drawing based on the pressure detected by the pressure sensor can control the line width and the transparency in a preferable manner even when there is no actual touch surface.

<FIG> is a diagram illustrating a configuration of a spatial position indicating system <NUM> according to an embodiment of the present invention. As illustrated in the figure, the spatial position indicating system <NUM> according to the present embodiment includes a computer <NUM>, a virtual reality display <NUM>, a plane position sensor <NUM>, an electronic pen <NUM>, position detection devices 7a and 7b, and spatial position sensors 8a to 8c. The spatial position sensors 8a to 8c are provided in the plane position sensor <NUM>, the virtual reality display <NUM>, and the electronic pen <NUM>, respectively.

In principle, each device illustrated in <FIG> is provided in a room. In the spatial position indicating system <NUM>, almost the entire room can be used as a virtual reality space.

The computer <NUM> includes a control unit 2a and a memory 2b. Each processing performed by the computer <NUM> described below is performed by the control unit 2a reading and executing a program stored in the memory 2b.

The computer <NUM> is connected to each of the virtual reality display <NUM>, the position detection devices 7a and 7b, and the plane position sensor <NUM> by wire or wirelessly. In the case of wired communication, it is preferable to use a USB (Universal Serial Bus), for example. In the case of wireless communication, it is preferable to use a wireless LAN (Local Area Network) such as Wi-Fi (Wireless Fidelity) (registered trademark) or near-field communication such as Bluetooth (registered trademark), for example. It is noted that when the plane position sensor <NUM> and the virtual reality display <NUM> have a function as a computer, this computer may constitute a part of or the entire computer <NUM>.

The computer <NUM> has a function of displaying a virtual reality space on the virtual reality display <NUM>. This virtual reality space may be a VR (Virtual Reality) space, an AR (Augmented Reality) space, or an MR (Mixed Reality) space. When the VR space is displayed, the user wearing the virtual reality display <NUM> recognizes a virtual reality and is disconnected from the real world. By contrast, when the AR space or the MR space is displayed, the user wearing the virtual reality display <NUM> recognizes a space in which the virtual reality and the real world are mixed.

The computer <NUM> functions as a rendering device that renders various 3D objects in the virtual reality space set with the positions of the position detection devices 7a and 7b as a reference. The computer <NUM> also updates the display of the virtual reality display <NUM> according to the result of the rendering. Accordingly, various 3D objects appear in the virtual reality space displayed on the virtual reality display <NUM>. The computer <NUM> performs rendering based on 3D object information stored in the memory 2b. The 3D object information indicates the shape, position, and orientation of the corresponding 3D object in the virtual reality space indicating the virtual reality space set by the computer <NUM> and is stored in the memory 2b for each 3D object to be rendered.

The 3D objects rendered by the computer <NUM> include 3D objects such as the plane position sensor <NUM> and the electronic pen <NUM> illustrated in <FIG> that also exist in reality (hereinafter referred to as "first 3D objects") and 3D objects such as a virtual tablet (not illustrated) that do not exist in reality (hereinafter referred to as "second 3D objects"). When rendering these 3D objects, the computer <NUM> first detects the position and orientation of the spatial position sensor 8b in the real space and acquires viewpoint information indicating the viewpoint of the user based on the result of the detection.

When rendering first 3D objects, the computer <NUM> further detects the positions and orientations of the spatial position sensors (e.g., the spatial position sensors 8a and 8c) in the real space, which are mounted in the respective objects, and stores the result of the detection in the memory 2b. Then, the computer <NUM> renders the first 3D objects in the virtual reality space based on the stored positions and orientations, the above-described viewpoint information, and the shapes stored for the first 3D objects. In addition, for the electronic pen <NUM> in particular, the computer <NUM> performs processes of detecting the position of the spatial position sensor 8c to detect an operation performed by the user in the virtual reality space, and based on the result, newly creating a second 3D object (that is, newly storing 3D object information in the memory 2b) or moving or updating a second 3D object that is already held (that is, updating 3D object information that is already stored in the memory 2b).

By contrast, when rendering a second 3D object, the computer <NUM> renders the second 3D object in the virtual reality space based on the corresponding 3D object information stored in the memory 2b and the above-described viewpoint information.

The virtual reality display <NUM> is a VR display (head-mounted display) that is worn on the head of a human when used. While there are various types of commercially available virtual reality displays such as "a transmissive type" or "a non-transmissive type" or "a glasses type" or "a hat type," any of these virtual reality displays can be used as the virtual reality display <NUM>.

The virtual reality display <NUM> is connected to each of the spatial position sensors 8a and the electronic pen <NUM> (including the spatial position sensor 8c) by wire or wirelessly. Through this connection, each of the spatial position sensors 8a and 8c notifies the virtual reality display <NUM> of light reception level information described later. The virtual reality display <NUM> notifies the computer <NUM> of the light reception level information notified by each of the spatial position sensors 8a and 8c, together with light reception level information of the spatial position sensor 8b incorporated in the virtual reality display <NUM>. The computer <NUM> detects the position and orientation of each of the spatial position sensors 8a to 8c in the real space based on the corresponding light reception level information notified in this manner.

The plane position sensor <NUM> is a device including an input surface 4a and a plurality of electrodes (not illustrated) arranged so as to cover the entire input surface 4a. The input surface 4a is preferably a flat surface and can be made of a material suitable for a pen tip of the electronic pen <NUM> to slide thereon. The plurality of electrodes plays a role of detecting a pen signal (described later) transmitted by the electronic pen <NUM>. The pen signal detected by each electrode is supplied to the computer <NUM>. Based on the supplied pen signal, the computer <NUM> acquires the position indicated by the electronic pen <NUM> in the input surface 4a and various kinds of data transmitted by the electronic pen <NUM>. The plane position sensor <NUM> may be incorporated in a tablet terminal having a display function and a processor, for example. In this case, the processor of the tablet terminal can constitute a part of or the entire computer <NUM>.

The spatial position sensors 8a are fixedly installed on a surface of the plane position sensor <NUM>. Therefore, the positions and orientations of the spatial position sensors 8a detected by the computer <NUM> indicate the position and orientation of the input surface 4a in a virtual reality space coordinate system.

The electronic pen <NUM> is a position indicating device having a pen shape. The electronic pen <NUM> has a function as an input device for the plane position sensor <NUM> (hereinafter referred to as a "tablet input function") and a function as an input device for the computer <NUM> (hereinafter referred to as a "virtual reality space input function"). The tablet input function includes a function of indicating a position in the input surface 4a of the plane position sensor <NUM>. Meanwhile, the virtual reality space input function includes a function of indicating a position in the virtual reality space. Details of each function will be described later.

The position detection devices 7a and 7b are base station devices that are included in a position detection system for detecting the positions of the spatial position sensors 8a to 8c. Each of the position detection devices 7a and 7b is capable of emitting a laser signal while changing its direction under the control of the computer <NUM>. Each of the spatial position sensors 8a to 8c includes a plurality of light receiving sensors. The light receiving sensors receive laser signals emitted by the respective position detection devices 7a and 7b to acquire light reception level information including their respective light reception levels. Each light reception level information acquired in this manner is supplied to the computer <NUM> via the virtual reality display <NUM> as described above. It is noted that while, in the present embodiment, the position detection devices 7a and 7b have the configuration in which laser signals can be emitted, the configuration is not limited thereto. Another possible configuration may be, for example, to use other non-visible light sensors, visible light sensors, or a combination thereof.

<FIG> is a perspective view of the external appearance of the electronic pen <NUM>. As illustrated in the figure, the electronic pen <NUM> includes a cylindrical external housing 5a. The external housing 5a accommodates a pen tip 5b (position indicating portion) for indicating a position in the input surface 4a of the plane position sensor <NUM>. It is noted that although a gripping force sensor <NUM> described later and various members included in various switches are attached to a surface of the actual electronic pen <NUM>, drawing of these members is omitted in <FIG>.

When the user performs an input using the tablet input function, the user holds the external housing 5a with one hand and brings the pen tip 5b into contact with the input surface 4a of the plane position sensor <NUM>. Subsequently, the user moves the pen tip 5b on the input surface 4a while maintaining the contact. In this manner, the user performs the input operation with the electronic pen <NUM>. By contrast, when the user performs an input using the virtual reality space input function, the user holds the external housing 5a with one hand and moves the electronic pen <NUM> in the air. In this manner, the user performs the input operation with the electronic pen <NUM>. The input using the virtual reality space input function includes an input to the virtual tablet described above.

<FIG> is a schematic block diagram illustrating functional blocks of the electronic pen <NUM>. As illustrated in the figure, the electronic pen <NUM> includes a processing unit <NUM>, a plane communication unit <NUM>, a spatial communication unit <NUM>, a spatial position detection unit <NUM>, a pen pressure sensor <NUM>, the gripping force sensor <NUM> (pressure sensor), and a force sense generation unit <NUM>. It is noted that the electronic pen <NUM> may include only one of the pen pressure sensor <NUM> and the gripping force sensor <NUM>, and the following description also includes such a case.

The processing unit <NUM> includes a processor that is connected to each of the other units in the electronic pen <NUM> and controls these units while performing various processes described later. The processing unit <NUM> reads and executes a program stored in an internal memory, not illustrated, to control each of the other units in the electronic pen <NUM> and perform various processes described later.

The plane communication unit <NUM> is a functional unit that transmits and receives signals to and from the computer <NUM> via the plane position sensor <NUM> under the control of the processing unit <NUM>. In this transmission/reception, the plurality of electrodes arranged in the input surface 4a of the plane position sensor <NUM> and a pen tip electrode (not illustrated) provided in the vicinity of the pen tip 5b of the electronic pen <NUM> are used as antennas. Further, this transmission/reception includes a case where signals are unidirectionally transmitted from the electronic pen <NUM> to the plane position sensor <NUM> and a case where signals are bidirectionally transmitted and received between the electronic pen <NUM> and the plane position sensor <NUM>. The following description continues on the assumption of the latter case. A signal transmitted from the plane position sensor <NUM> to the electronic pen <NUM> will be referred to as a "beacon signal" while a signal transmitted from the electronic pen <NUM> to the plane position sensor <NUM> will be referred to as a "pen signal. " For example, an electromagnetic induction method or an active capacitive method can be used as a concrete method of the signal transmission/reception for this case.

The beacon signal is a signal transmitted by the computer <NUM> at predetermined time intervals, for example, and includes a command for controlling the electronic pen <NUM> from the computer <NUM>. The pen signal includes a burst signal (plane position information for indicating the position of the pen tip 5b in the input surface 4a) and a data signal. The burst signal is an unmodulated carrier wave. The data signal is obtained by modulating a carrier wave using data requested to be transmitted by the command.

The spatial communication unit <NUM> has a function of transmitting and receiving signals to and from the computer <NUM> via the virtual reality display <NUM> under the control of the processing unit <NUM>. These signals are transmitted and received by wire or wirelessly as described above. The plane position sensor <NUM> does not intervene in transmission and reception of the signals between the spatial communication unit <NUM> and the computer <NUM>.

The spatial position detection unit <NUM> is a functional unit including the spatial position sensor 8c illustrated in <FIG> and plays a role of detecting the above-described light reception level information (spatial position information for indicating the position of the electronic pen <NUM> in the space) through interaction with external devices (specifically, the position detection devices 7a and 7b). Specifically, the spatial position detection unit <NUM> performs processes of periodically or continuously performing an operation of detecting laser signals transmitted by the position detection devices 7a and 7b, generating light reception level information corresponding to the detected laser signals, and supplying the light reception level information to the processing unit <NUM> each time.

The pen pressure sensor <NUM> is a sensor capable of detecting a force (pen pressure) applied to the pen tip 5b and includes, for example, a capacitance sensor (not illustrated) whose capacitance value changes according to the pen pressure. The processing unit <NUM> has functions of acquiring the pen pressure detected by the pen pressure sensor <NUM> and generating pen pressure information regarding the acquired pen pressure. The pen pressure information is, for example, a digital value obtained by performing analog-digital conversion on the pen pressure that is analog information.

The gripping force sensor <NUM> is a sensor capable of detecting a force (=a gripping force) on the surface of the external housing 5a of the electronic pen <NUM>. A specific configuration of the gripping force sensor <NUM> will be described later in detail with reference to the drawings. The processing unit <NUM> has functions of acquiring the gripping force detected by the gripping force sensor <NUM> and generating pressure information regarding the acquired gripping force. The pressure information is, for example, a digital value obtained by performing analog-digital conversion on the gripping force that is analog information.

The force sense generation unit <NUM> has a function of generating a force sense according to a control signal supplied from the computer <NUM>. The force sense here is, for example, the vibration of the external housing 5a. For example, when the pen tip 5b is in contact with a surface of the virtual tablet (more accurately, when the pen tip 5b is present within a predetermined distance from the surface of the virtual tablet), the computer <NUM> supplies the control signal to the electronic pen <NUM> via the spatial communication unit <NUM>. This causes the force sense generation unit <NUM> to generate a force sense. Accordingly, the user can gain a feeling that the pen tip 5b collides with the surface of the virtual tablet that does not exist in reality.

When an input is performed using the tablet input function, the processing unit <NUM> first performs an operation of detecting a beacon signal transmitted from the computer <NUM> via the plane communication unit <NUM>. As a result, when the beacon signal has been detected, the processing unit <NUM> sequentially outputs the above-described burst signal and data signal to the plane communication unit <NUM> as a response to the beacon signal. The data signal output in this manner can include the above-described pen pressure information or pressure information. The plane communication unit <NUM> transmits the burst signal and the data signal input in this manner to the computer <NUM> via the plane position sensor <NUM>.

When the computer <NUM> receives the burst signal via the plane position sensor <NUM>, the computer <NUM> detects a plane position indicating the position of the pen tip 5b in the input surface 4a based on the reception intensity of the burst signal in each of the plurality of electrodes arranged in the input surface 4a. Further, the computer <NUM> acquires data transmitted by the electronic pen <NUM> by receiving the data signal using the electrode closest to the detected plane position among the plurality of electrodes arranged in the input surface 4a. Then, the computer <NUM> performs 2D drawing based on the detected plane position and the received data. Details of 2D drawing will be described later. The tablet input function is realized in this manner.

By contrast, when an input is performed using the virtual reality space input function, the processing unit <NUM> sequentially outputs the light reception level information supplied from the spatial position detection unit <NUM> to the spatial communication unit <NUM>. Further, the processing unit <NUM> also outputs the pen pressure information or the pressure information generated as described above to the spatial communication unit <NUM>, together with the light reception level information. The spatial communication unit <NUM> transmits each information input in this manner to the computer <NUM>.

When the computer <NUM> receives each information described above from the spatial communication unit <NUM>, the computer <NUM> detects a spatial position indicating the position of the electronic pen <NUM> in the space based on the received light reception level information. In this case, information indicating the shape of the electronic pen <NUM> and a relative positional relation between the spatial position detection unit <NUM> and the pen tip 5b may be stored in the computer <NUM> in advance, and the computer <NUM> may convert the position obtained directly from the light reception level information into the position of the pen tip 5b based on this information and detect the position obtained by the conversion as a spatial position. The computer <NUM> performs 3D drawing based on the detected spatial position and the received pen pressure information or pressure information. Details of 3D drawing will also be described later. The virtual reality space input function is realized in this manner.

<FIG> is a processing flow diagram illustrating processing performed by the processing unit <NUM> of the electronic pen <NUM>. Further, <FIG> is a processing flow diagram illustrating details of a tablet input process (step S1) illustrated in <FIG>. <FIG> is a processing flow diagram illustrating details of a virtual reality space input process (step S2) illustrated in <FIG>. Hereinafter, the operation of the electronic pen <NUM> will be described in detail with reference to these <FIG>.

First, as illustrated in <FIG>, the processing unit <NUM> performs the tablet input process (step S1) and the virtual reality space input process (step S2) in a time division manner.

Next, referring to <FIG>, the processing unit <NUM>, which performs the tablet input process, first performs an operation of detecting a beacon signal using the plane communication unit <NUM> (steps S10 and S11). In this detection operation, the plane communication unit <NUM> attempts to detect a beacon signal by demodulating a signal that has reached the pen tip electrode described above. As a result, when the beacon signal has not been detected, the processing unit <NUM> ends the tablet input process. On the other hand, when the beacon signal has been detected, the processing unit <NUM> outputs a burst signal to the plane communication unit <NUM>, causing the plane communication unit <NUM> to transmit the burst signal (step S12).

The subsequent process differs depending on whether or not the electronic pen <NUM> includes the pen pressure sensor <NUM>. In the former case, the processing unit <NUM> acquires a pen pressure from the output of the pen pressure sensor <NUM> (step S13), and transmits, from the plane communication unit <NUM>, a data signal including pen pressure information regarding the acquired pen pressure (step S14). By contrast, in the latter case, the processing unit <NUM> acquires a gripping force from the output of the gripping force sensor <NUM> (step S15), and transmits, from the plane communication unit <NUM>, a data signal including pressure information regarding the acquired gripping force (step S16). After the transmission in step S14 or step S16, the processing unit <NUM> ends the tablet input process and starts the next virtual reality space input process (step S2), as can be understood from <FIG>.

Next, referring to <FIG>, the processing unit <NUM>, which performs the virtual reality space input process, first performs an operation of detecting laser signals using the spatial position detection unit <NUM> (steps S20 and S21). As a result, when no laser signal has been detected, the processing unit <NUM> ends the virtual reality space input process. By contrast, when laser signals have been detected, the processing unit <NUM> acquires light reception level information corresponding to the laser signals from the spatial position detection unit <NUM> and causes the spatial communication unit <NUM> to transmit the light reception level information (step S22).

The subsequent process differs depending on whether or not the electronic pen <NUM> includes the pen pressure sensor <NUM>. In the latter case, the processing unit <NUM> acquires a gripping force from the output of the gripping force sensor <NUM> (step S26), and transmits, from the spatial communication unit <NUM>, pressure information regarding the acquired gripping force (step S27). By contrast, in the former case, the processing unit <NUM> acquires a pen pressure from the output of the pen pressure sensor <NUM> (step S23) and determines whether or not the acquired pen pressure exceeds a predetermined value (step S24). This determination is to determine whether or not the pen tip 5b is in contact with an actual surface and is performed so as not to use the pen pressure when the pen tip 5b is not in contact therewith. It is noted that the actual surface here corresponds to a surface such as a simple plate. Accordingly, for example, arranging the actual plate so as to match the display position of the virtual tablet makes it possible to use the pen pressure sensor <NUM> for the virtual tablet.

When it is determined in step S24 that the pen pressure exceeds the predetermined value, the processing unit <NUM> transmits, from the spatial communication unit <NUM>, pen pressure information regarding the acquired pen pressure (step S25). On the other hand, when it is determined in step S24 that the pen pressure does not exceed the predetermined value, the processing unit <NUM> advances the process to step S26 and transmits the pressure information (steps S26 and S27). After the transmission in step S25 or step S27, the processing unit <NUM> ends the virtual reality space input process and starts the next tablet input process (step S1), as can be understood from <FIG>.

<FIG> is a processing flow diagram illustrating processing performed by the control unit 2a of the computer <NUM>. Further, <FIG> is a processing flow diagram illustrating details of a correlation acquisition process (step S30) illustrated in <FIG>. <FIG> is a processing flow diagram illustrating details of a tablet drawing process (step S35) illustrated in <FIG>. <FIG> is a processing flow diagram illustrating details of a virtual reality space drawing process (step S41) illustrated in <FIG>. Hereinafter, the operation of the computer <NUM> will be described in detail with reference to these figures.

As illustrated in <FIG>, the control unit 2a first performs the correlation acquisition process (step S30).

The correlation acquisition process is a process of acquiring a correlation f between a pen pressure detected by the pen pressure sensor <NUM> and a gripping force detected by the gripping force sensor <NUM>. In this process, as illustrated in <FIG>, the control unit 2a first causes the electronic pen <NUM> to perform a pen pressure detection operation by the pen pressure sensor <NUM> and a gripping force detection operation by the gripping force sensor <NUM> at the same time over a predetermined number of times, and receives pen pressure information and pressure information from the electronic pen <NUM> each time (steps S50 to S52).

After repeating the predetermined number of times, the control unit 2a acquires the correlation f between the pen pressure and the gripping force based on multiple combinations of the pen pressure and the gripping force that have been acquired (step S53) and ends the correlation acquisition process. The correlation f acquired in this manner is, for example, a correlation function representing a correlation between the pen pressure and the gripping force. In one example, the correlation f is expressed in the form of a pen pressure=f(gripping force). The following description continues on the assumption that the correlation f is used.

<FIG> are diagrams for describing the correlation f between a pen pressure and a gripping force. In these figures, P represents a pen pressure, G represents a gripping force, and F represents a frictional force between the user's hand and the surface of the electronic pen <NUM>.

First, referring to <FIG>, when the user attempts to draw a line while holding the electronic pen <NUM> perpendicularly to the input surface 4a, P≈F holds. Further, a relation of F≈µG holds between the gripping force G and the friction force F. It is noted that µ is a friction coefficient between the user's hand and the surface of the electronic pen <NUM>. Therefore, P≈µG holds.

Next, referring to <FIG>, when the user attempts to draw a line while holding the electronic pen <NUM> so as to incline the electronic pen <NUM> by an angle θ relative to a normal direction of the input surface 4a, F≈P'=Pcosθ holds. It is noted that P' is a component of force of the pen pressure P in a pen axis direction. Therefore, in this case, Pcosθ=µG holds from the relation of F≈µG described above.

The relation of Pcosθ=µG also includes the case illustrated in <FIG>. Therefore, the correlation f can be universally expressed when f(G)=µG/cosθ holds. However, since the friction coefficient µ and the angle θ appearing therein are amounts that can vary from user to user, it is necessary to obtain a pen pressure=f(gripping force) for each user after all. Therefore, it is necessary to perform the correlation acquisition process as described with reference to <FIG>.

Returning to <FIG>, the control unit 2a, which has completed the correlation acquisition process, subsequently sets a drawing region in the virtual reality space (step S31). The drawing region is a region in which 3D drawing is performed by the electronic pen <NUM>.

<FIG> are diagrams each illustrating a specific example of the drawing region. <FIG> illustrates an example in which a region within a predetermined distance from a display surface of a virtual tablet B is set as a drawing region A. The drawing region A according to this example is a region in which an input to the virtual tablet B is possible. When a detected spatial position is within this type of drawing region A, the control unit 2a performs 3D drawing after replacing the detected spatial position with a spatial position obtained by projecting the detected spatial position on the display surface of the virtual tablet B during the virtual reality space drawing process illustrated in step S35 described later. This allows the user to draw a plane figure on the display surface of the virtual tablet B. It is noted that the above-described predetermined distance is preferably set to a value greater than <NUM>. This is because when the user attempts to make an input to the display surface of the virtual tablet B with the electronic pen <NUM>, it is difficult to keep the electronic pen <NUM> in contact with the display surface that does not physically exist.

<FIG> illustrates an example in which any three-dimensional space is set as the drawing region A. When a detected spatial position is within the drawing region A, the control unit 2a performs 3D drawing without performing the replacement as in the example of <FIG>. This allows the user to draw a three-dimensional figure in the drawing region A.

Returning to <FIG>, the control unit 2a subsequently performs an operation of detecting light reception level information and a burst signal (step S32). Specifically, this process includes a process of receiving light reception level information from the electronic pen <NUM> by wire or wirelessly and a process of receiving a burst signal from the electronic pen <NUM> via the plane position sensor <NUM>. The control unit 2a performs step S32, and when, as a result, the burst signal has been detected (determination is positive in step S33), the control unit 2a advances the process to step S34. When the burst signal has not been detected (determination is negative in step S33), the control unit 2a advances the process to step S36.

The control unit 2a, which has advanced the process to step S34, detects the above-described plane position (the position of the pen tip 5b in the input surface 4a) based on the detected burst signal (step S34). After that, for example, the control unit 2a performs the tablet drawing process for performing 2D drawing on the display of the tablet terminal including the plane position sensor <NUM> (step S35).

In the tablet drawing process, as illustrated in <FIG>, the control unit 2a first performs an operation of detecting a data signal transmitted by the electronic pen <NUM> via the plane position sensor <NUM> (step S60). Then, the control unit 2a determines which of the pen pressure information and the pressure information is included in the data signal (step S61).

When the pen pressure information is determined to be included in step S61, the control unit 2a further determines whether or not the pen pressure indicated by the pen pressure information is equal to or less than a predetermined normal ON load (e.g., <NUM>) (step S68). As a result, when the pen pressure is determined to be equal to or less than the normal ON load, the control unit 2a ends the process without performing 2D drawing. This is a process when it is considered that the pen tip 5b of the electronic pen <NUM> is not in contact with the input surface 4a (what is generally called hover state). On the other hand, when the pen pressure is determined to be greater than the normal ON load in step S68, the control unit 2a performs 2D drawing on the display of the tablet terminal that is the plane position sensor <NUM>, for example, based on the plane position detected in step S34 and the pen pressure indicated by the pen pressure information (step S69).

The 2D drawing performed in step S69 will be specifically described here. The 2D drawing includes a rendering process and a display process. In the rendering process, the control unit 2a arranges a circle having a radius matching the corresponding pen pressure at each of a series of plane positions that are sequentially detected. Then, smoothly connecting the circumferences of the respective circles generates two-dimensional curve data (ink data) having a width corresponding to the pen pressure. The display process is a process of displaying the curve data generated in this manner on the display of the tablet terminal that is the plane position sensor <NUM>, for example.

When the pressure information is determined to be included in step S61, the control unit 2a performs a process for converting the gripping force indicated by the pressure information into a pen pressure (steps S62 to S67). Specifically, the control unit 2a first determines whether a reset flag A is true or false (step S62). The reset flag A is a flag that indicates whether or not the electronic pen <NUM> has just entered a range in which the burst signal reaches the plane position sensor <NUM>. When the electronic pen <NUM> has just entered the range, the determination result in step S62 is false.

The control unit 2a, which has made the false determination in step S62, further determines whether or not the gripping force indicated by the pressure information is equal to or greater than a predetermined value (step S63). Then, when the gripping force is determined to be less than the predetermined value, the gripping force indicated by the pressure information is set as an initial gripping force (step S64). When the gripping force is determined to be equal to or greater than the predetermined value, the predetermined value is set as the initial gripping force (step S65). It is noted that the initial gripping force is a variable that is used to treat the gripping force when the electronic pen <NUM> enters the range in which the burst signal reaches the plane position sensor <NUM> (at the time of pen down) as <NUM>. Further, step S65 defines the upper limit of the initial gripping force and is used, for example, to prevent the gripping force necessary for increasing the line width from becoming too large, preventing the user from being unable to exert a sufficient pen pressure.

<FIG> is a diagram for describing the meaning of the initial gripping force. In a graph illustrated in this figure, the horizontal axis represents a force on the surface of the external housing 5a, while the vertical axis represents a gripping force detected by the gripping force sensor <NUM>. As a gripping force, the control unit 2a does not use the gripping force itself detected by the gripping force sensor <NUM> but uses a value obtained by subtracting the initial gripping force from the gripping force. With this configuration, the user can input a pen pressure using the gripping force by increasing or decreasing the gripping force with the gripping force at the time of pen down as a reference.

Returning to <FIG>, when the control unit 2a performs step S64 or step S65, the control unit 2a sets the reset flag A to true (step S66). After that, the control unit 2a performs the process of converting the gripping force into a pen pressure using the correlation f (step S67). The step S67 is also performed when true determination is made in step S62. In step S67, the control unit 2a substitutes a value obtained by subtracting the initial gripping force from the gripping force indicated by the pressure information into the correlation f as a gripping force. Accordingly, as described with reference to <FIG>, the user can input a pen pressure using the gripping force by increasing or decreasing the gripping force with the gripping force at the time of pen down as a reference.

The control unit 2a, which has obtained the pen pressure in step S67, performs steps S68 and S69 using this pen pressure. These steps realize 2D drawing similar to the case where the pen pressure information is included in the data signal.

The control unit 2a, which has performed step S69, ends the tablet drawing process. Then, the control unit 2a returns to step S32 of <FIG> to perform the operation of detecting the next light reception level information and burst signal.

The control unit 2a, which has advanced the process to step S36 of <FIG>, first sets the reset flag A to false (step S36). This makes it possible to return the reset flag A to false when the electronic pen <NUM> is moved out of the range in which the burst signal reaches the plane position sensor <NUM>.

Subsequently, the control unit 2a determines whether or not light reception level information has been detected by the detection operation in step S32 (step S37). Then, when the light reception level information is determined to have been detected, the control unit 2a detects the above-described spatial position (the position of the electronic pen <NUM> (or its pen tip 5b) in the space) based on the detected light reception level information (step S38). Subsequently, the control unit 2a determines whether or not the detected spatial position is the position within the drawing region set in step S31 (step S39).

The control unit 2a, which has determined in step S39 that the detected spatial position is the position within the drawing region, performs the virtual reality space drawing process for performing 3D drawing in the virtual reality space (step S41). Here, as indicated by a broken line in <FIG>, the process of replacing the detected spatial position with a spatial position obtained by projecting the detected spatial position on the display surface of the virtual tablet may be inserted between step S39 and step S41 (step S40). The step S40 is a process that can be performed only when the drawing region including the detected spatial position is a region set on the display surface of the virtual tablet B as illustrated in <FIG>. This allows the user to draw a plane figure on the display surface of the virtual tablet, as described above.

In the virtual reality space drawing process, as illustrated in <FIG>, the control unit 2a first performs an operation of receiving pen pressure information or pressure information (step S70). Then, the control unit 2a determines which of the pen pressure information and the pressure information has been received (step S71).

When the pen pressure information is determined to have been received in step S71, the control unit 2a further determines whether or not the pen pressure indicated by the pen pressure information is equal to or less than the predetermined normal ON load (e.g., <NUM>) (step S80). As a result, when the pen pressure is determined to be equal to or less than the normal ON load, the control unit 2a ends the process without performing 3D drawing. This is a process when it is considered that the pen tip 5b of the electronic pen <NUM> is not in contact with the above-described actual plate (for example, the one that is arranged so as to match the display position of the virtual tablet). On the other hand, when the pen pressure is determined to be greater than the normal ON load in step S80, the control unit 2a performs 3D drawing in the virtual reality space based on the spatial position detected in step S38 (or the spatial position acquired in step S40) and the pen pressure indicated by the pen pressure information (step S81).

As in the case of 2D drawing, the 3D drawing performed in step S79 also includes a rendering process and a display process. In the rendering process, the control unit 2a arranges a sphere having a radius matching the corresponding pen pressure at each of a series of spatial positions that are sequentially detected. Then, smoothly connecting the surfaces of the respective spheres generates three-dimensional curve data having a cross-sectional diameter corresponding to the pen pressure. The display process is a process of displaying the curve data generated in this manner in the virtual reality space. It is noted that when the control unit 2a fixes the spatial position to a position in the display surface of the virtual tablet by performing step S40, the control unit 2a may perform 2D drawing in the display surface, instead of 3D drawing.

When the pressure information is determined to have been received in step S71, the control unit 2a performs a process for converting the gripping force indicated by the pressure information into a pen pressure (steps S72 to S77). The details of this process are similar to the processes in steps S62 to S67 illustrated in <FIG>. In step S77, the pen pressure as the result of the conversion is acquired. It is noted that, in steps S72 to S77, a reset flag B is used instead of the reset flag A. The reset flag B is a flag that indicates whether or not the electronic pen <NUM> has just entered the drawing region. When the electronic pen <NUM> has just entered the drawing region, the determination result in step S72 is false.

The control unit 2a, which has obtained the pen pressure in step S77, performs steps S78 and S79 using this pen pressure. These steps S78 and S79 are processes similar to steps S80 and S81, except that instead of the normal ON load, the control unit 2a uses a value different from the normal ON load, preferably a space ON load that is set to a value greater than the normal ON load (that is, the control unit 2a determines in step S78 whether or not the pen pressure indicated by the pressure information is equal to or less than the predetermined space ON load (> normal ON load)). These steps realize 3D drawing similar to the case where the pen pressure information is received.

Compared to the case where the electronic pen <NUM> is operated while in contact with a fixed surface such as the input surface 4a, a gripping force increases as much as necessary to support the weight of the electronic pen <NUM> when the electronic pen <NUM> is operated while being floated in the air. To deal with such a greater gripping force, the space ON load is used in step S78, instead of the normal ON load. By using the space ON load greater than the normal ON load in step S78, it is possible to appropriately perform 3D drawing despite such an increase in the gripping force.

The control unit 2a, which has performed step S79, ends the virtual reality space drawing process. Then, the control unit 2a returns to step S32 of <FIG> to perform the operation of detecting the next light reception level information and burst signal. In addition, when the control unit 2a determines in step S37 of <FIG> that the light reception level information has not been detected and when the control unit 2a determines in step S39 of <FIG> that the spatial position is not within the drawing region, the control unit 2a sets the reset flag B to false (step S42). After that, the control unit 2a returns to step S32 to perform the operation of detecting the next light reception level information and burst signal. Performing step S42 can return the reset flag B to false when the electronic pen <NUM> is moved out of the drawing region (including a case where the electronic pen <NUM> is moved out of the virtual reality space).

As described above, according to the present embodiment, the electronic pen <NUM> is capable of outputting pressure information regarding a gripping force, and the computer <NUM> is capable of performing 3D drawing and 2D drawing based on the pressure information regarding the gripping force. With this configuration, even when there is no actual touch surface, the line width and the transparency can be controlled in a preferable manner.

Hereinafter, a specific configuration of the gripping force sensor <NUM> will be described in detail with reference to the drawings.

<FIG> is a diagram illustrating a structure of the gripping force sensor <NUM> according to a first example. The gripping force sensor <NUM> according to the present example includes a touch sensor capable of sensing a depressing force using a pressure-sensitive method, for example, and is provided on a side surface of the external housing 5a. The processing unit <NUM> for this case acquires the depressing force detected by the gripping force sensor <NUM> as a gripping force.

<FIG> is a diagram illustrating a structure of the gripping force sensor <NUM> according to a second example. The gripping force sensor <NUM> according to the present example includes a button mechanism capable of detecting an amount of depression in a stepwise or continuous manner and is provided on the side surface of the external housing 5a. The processing unit <NUM> for this case acquires the amount of depression detected by the gripping force sensor <NUM> as a gripping force. Specific examples of the button mechanism include an actuator, a Hall effect device, a strain gauge, and the like.

<FIG> depicts diagrams illustrating a structure of the gripping force sensor <NUM> according to a third example. The gripping force sensor <NUM> according to the present example also serves as the pen pressure sensor <NUM> and includes a capacitor having a structure in which a dielectric <NUM> is provided between two electrode plates <NUM> and <NUM>. One end of a core body <NUM> is included in the pen tip 5b while another end of the core body <NUM> is connected to the electrode plate <NUM>. Further, the electrode plate <NUM> is connected to a button mechanism <NUM>, which is provided on the side surface of the external housing 5a.

The capacitor according to the present example is configured such that the distance between the electrode plate <NUM> and the electrode plate <NUM> changes according to a force applied to the pen tip 5b and, as a result, the capacitance also changes. Further, the capacitor according to the present example is configured such that, as can be understood by comparing <FIG> with <FIG>, the electrode plate <NUM> moves laterally according to an amount of depression of the button mechanism <NUM> and as a result, the capacitance changes. In the tablet input process illustrated in <FIG>, the processing unit <NUM> according to the present example regards the capacitor according to the present example as the pen pressure sensor <NUM> and acquires a pen pressure from the capacitance thereof. By contrast, in the virtual reality space input process illustrated in <FIG>, the processing unit <NUM> according to the present example regards the capacitor according to the present example as the gripping force sensor <NUM> and acquires a gripping force from the capacitance thereof. According to the present example, both the gripping force sensor <NUM> and the pen pressure sensor <NUM> can be implemented by one capacitor.

It is noted that although description has been given of the example of using the capacitor in <FIG>, a load cell can also serve as both the gripping force sensor <NUM> and the pen pressure sensor <NUM>. Since the load cell can measure a stress in each of an X direction, a Y direction, and a Z direction individually, a pen pressure that is a force in the pen axis direction and a gripping force that is a force perpendicular to the pen axis direction can be individually measured based on the measured individual stresses.

<FIG> is a diagram illustrating a structure of the gripping force sensor <NUM> according to a fourth example. The gripping force sensor <NUM> according to the present example has a structure in which a pressure-sensitive sensor <NUM>, a substrate <NUM>, and a dome button <NUM> are stacked, and is provided on the side surface of the external housing 5a such that the surface on the dome button <NUM> side is exposed. The pressure-sensitive sensor <NUM> is a sensor capable of sensing a depressing force applied to the surface of the external housing 5a. The dome button <NUM> is a button mechanism capable of being turned on and off by the user.

<FIG> depicts processing flow diagrams illustrating processing performed by the processing unit <NUM> of the electronic pen <NUM> when the gripping force sensor <NUM> according to the fourth example is used. <FIG> is a processing flow diagram in which steps S90 to S95 are added to the processing flow diagram illustrated in <FIG>. Further, <FIG> is a processing flow diagram in which step S96 is added to the processing flow diagram illustrated in <FIG> or <FIG>. Hereinafter, an operation of the electronic pen <NUM> including the gripping force sensor <NUM> according to the fourth example will be described with reference to <FIG>.

First, as illustrated in <FIG>, the processing unit <NUM> first determines whether the dome button <NUM> is on or off (step S90). As a result, when the dome button <NUM> is determined to be off, the processing unit <NUM> sets a reset flag C to false (step S95) and starts the tablet input process of step S1. The reset flag C is a flag that indicates whether or not the dome button <NUM> has been just pressed. When the dome button <NUM> has been just pressed, the determination result in step S91 described later is false.

Next, the processing unit <NUM>, which has determined that the dome button <NUM> is on in step S90, determines whether the reset flag C is true or false (step S91). The processing unit <NUM>, which has determined that the reset flag C is true here, starts the tablet input process of step S1 immediately. On the other hand, when the reset flag C is determined to be false, the processing unit <NUM> acquires a gripping force from the gripping force sensor <NUM> (step S92) and sets the acquired gripping force as an initial gripping force (step S93). The initial gripping force here is a variable used for treating the gripping force when the dome button <NUM> is pressed as <NUM>, and is independent of the initial gripping force used in the computer <NUM> (the one used in the processing flow illustrated in <FIG> or <FIG>). The processing unit <NUM>, which has performed step S93, sets the reset flag C to true (step S94) and starts the tablet input process of step S1.

Next, as illustrated in <FIG>, the processing unit <NUM> uses a gripping force obtained by subtracting the initial gripping force from each of the gripping force acquired in step S15 of <FIG> and the gripping force acquired in step S26 of <FIG> as a gripping force (step S96). That is, the processing unit <NUM> transmits, to the computer <NUM>, pressure information regarding the gripping force obtained by subtraction in step S96, not the gripping force itself acquired in the corresponding step S15 or S26.

Since the processing unit <NUM> performs the above-described processing, the user of the electronic pen <NUM> according to the present example can input a pen pressure using a gripping force by increasing or decreasing the gripping force with a gripping force at the timing when the user turns on the dome button <NUM> on the user's own will as a reference.

<FIG> depicts diagrams illustrating a structure of the gripping force sensor <NUM> according to a fifth example. The gripping force sensor <NUM> according to the present example includes a capacitor and is provided on the side surface of the external housing 5a. The capacitor has a structure in which a dielectric <NUM> and a rubber <NUM> are provided between two electrode plates <NUM> and <NUM>. The processing unit <NUM> according to the present example acquires the capacitance of the capacitor, which is the gripping force sensor <NUM>, as a gripping force.

With the capacitor according to the present example, when the user depresses the electrode plate <NUM> located on the outer side, the rubber <NUM> is crushed according to its depressing force, decreasing the distance between the electrode plate <NUM> and the electrode plate <NUM> accordingly. This, as a result, increases the capacitance. In addition, when the user applies a force in the pen axis direction to the electrode plate <NUM> located on the outer side, the rubber <NUM> is deformed, causing the electrode plate <NUM> to slide in the pen axis direction as illustrated in <FIG>. This, as a result, decreases the capacitance. Therefore, with the gripping force sensor <NUM> according to the present example, not only a depressing force but also a force in the pen axis direction can be detected as a gripping force. It is noted that when the distance between the electrode plate <NUM> and the electrode plate <NUM> is d, an overlap area of the electrode plates <NUM> and <NUM> when no slide occurs is S, an amount of change of the overlap area due to a slide is ΔS, and the permittivity of members including the dielectric <NUM> and the rubber <NUM> is ε, the capacitance of the capacitor according to the present example is expressed by the following equation (<NUM>).

<FIG> depicts diagrams illustrating a structure of the gripping force sensor <NUM> according to a sixth example. As illustrated in the figure, the electronic pen <NUM> according to the present example includes a grip member <NUM>, which is attached to the external housing 5a. The gripping force sensor <NUM> according to the present example is incorporated in the grip member <NUM>. <FIG> illustrates the side surface of the electronic pen <NUM> with the grip member <NUM> attached. <FIG> illustrates an upper surface of the electronic pen <NUM> with the grip member <NUM> attached. <FIG> illustrates the electronic pen <NUM> being used with the grip member <NUM> attached.

As illustrated in <FIG>, the grip member <NUM> includes a cylindrical base 22a and a finger rest 22b. The base 22a is engaged with the external housing 5a. The finger rest 22b extends in an arch shape from one end of the base 22a. As illustrated in <FIG>, the user uses the electronic pen <NUM> with the index finger placed on the finger rest 22b. It is noted that although <FIG> illustrates an example in which the grip member <NUM> is a separate body from the external housing 5a, the grip member <NUM> and the external housing 5a may be integrally formed.

The gripping force sensor <NUM> is, for example, a strain gauge embedded in the finger rest 22b and is capable of detecting a force in the index finger of the user (a depressing force of the finger rest 22b). The processing unit <NUM> according to the present example acquires the force detected in this manner as a gripping force.

Here, incorporating an acceleration sensor in the electronic pen <NUM> or the grip member <NUM> allows the processing unit <NUM> to detect a user's operation of shaking the electronic pen <NUM>. By combining this with the detection of a depressing force of the finger rest 22b using the gripping force sensor <NUM>, an operation of tapping the touch surface can be simulated.

Claim 1:
A pen-type position indicating device (<NUM>) comprising:
a housing (5a);
a position indicating portion (5b) configured to indicate a position;
a first sensor (<NUM>) configured to detect a first pressure applied to the position indicating portion (5b);
a second sensor (<NUM>) configured to detect a second pressure applied to the housing (5a);
a first communication unit (<NUM>) configured to transmit the first pressure detected by the first sensor (<NUM>);
a second communication unit (<NUM>) configured to transmit the second pressure detected by the second sensor (<NUM>),
wherein the first communication unit (<NUM>) is a communication unit configured to transmit a data signal including the first pressure to a first device for applying the first pressure to the position indicating portion (5b), wherein the first device is a position sensor (<NUM>) including an input surface (4a) and a plurality of electrodes arranged so as to cover the input surface (4a), wherein the first communication unit (<NUM>) is further configured to transmit the data signal such that the first device can receive the data signal by using the plurality of electrodes, and
the second communication unit (<NUM>) is a communication unit further configured to transmit the second pressure to a second device for controlling generation of a three-dimensional object in a virtual reality space.