Patent Publication Number: US-RE47433-E

Title: Input apparatus, control apparatus, control system, control method, and handheld apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation of prior application Ser. No. 14/656,388, filed on Mar. 12, 2015, now U.S. Pat. No. RE46,076, which is a Reissue of prior application Ser. No. 12/521,364, filed on Jun. 26, 2009, issued as U.S. Pat. No. 8,395,583, and is a Reissue of prior application Ser. No. 12/521,364, filed on Jun. 26, 2009, issued as U.S. Pat. No. 8,395,583, which is a National Stage of International Application No. PCT/JP2008/071157 filed on Nov. 20, 2008 and which claims priority to Japanese Patent Application No. 2007-304877 filed on Nov. 26, 2007, the entire contents of which are being incorporated herein by reference, and accordingly, multiple reissue applications (the present application Ser. No. 15/212,887 and the above listed application Ser. No. 14/656,388) are associated with U.S. Pat. No. 8,395,583. 
    
    
     BACKGROUND 
     The present application relates to a 3-dimensional operation input apparatus for operating a GUI (Graphical User Interface), a control apparatus for controlling the GUI in accordance with information output from the input apparatus, a control system including those apparatuses, a control method, and a handheld apparatus. 
     Pointing devices, particularly a mouse and a touchpad, are used as controllers for GUIs widely used in PCs (Personal Computers). Not just as HIs (Human Interfaces) of PCs as in related art, the GUIs are now starting to be used as an interface for AV equipment and game devices used in living rooms etc. with, for example, televisions as image media. Various pointing devices that a user is capable of operating 3-dimensionally are proposed as controllers for the GUIs of this type (see, for example, Patent Documents 1 and 2). 
     Japanese Patent Application Laid-open No. 2001-56743 (paragraphs [0030] and [0031], FIG. 3) discloses an input apparatus including angular velocity gyroscopes of two axes, that is, two angular velocity sensors. Each angular velocity sensor is a vibration-type angular velocity sensor. For example, upon application of an angular velocity with respect to a vibrating body piezoelectrically vibrating at a resonance frequency, Coriolis force is generated in a direction orthogonal to a vibration direction of the vibrating body. The Coriolis force is in proportion to the angular velocity, so detection of the Coriolis force leads to detection of the angular velocity. The input apparatus of Japanese Patent Application Laid-open No. 2001-56743 (paragraphs [0030] and [0031], FIG. 3) detects angular velocities about two orthogonal axes by the angular velocity sensors, generates, in accordance with the angular velocities, a signal as positional information of a cursor or the like displayed by a display means, and transmits it to a control apparatus. 
     Japanese Patent No. 3,748,483 (paragraphs [0033] and [0041], FIG. 1) discloses a pen-type input apparatus including three (triaxial) acceleration sensors and three (triaxial) angular velocity sensors (gyro). The pen-type input apparatus executes various operations based on signals obtained by the three acceleration sensors and the three angular velocity sensors, to thus calculate a positional angle of the pen-type input apparatus. 
     However, there is a problem that, since a user moves an input apparatus unstably in air, it becomes difficult to perform an accurate pointing operation like placing a pointer at a specific position on a screen, for example. 
     To solve this problem, a variability function for velocities or accelerations of a pointer is used in a planar-operation-type pointing system generally used in PCs and the like. As an example of the variability function, Windows (registered trademark) adopts a function capable of changing velocities or accelerations of a pointer. By applying an acceleration function to a movement of a pointer, a velocity of the pointer becomes higher as a velocity of a pointing operation (e.g., velocity of mouse) becomes higher. Therefore, since the velocity of the pointer becomes low when a velocity of a mouse is low, an accurate pointing operation becomes possible. 
     The 3-dimensional operation input apparatus, however, does not include such an acceleration variability function. In other words, a time when a velocity of the input apparatus and a velocity of the pointer become linear is more intuitional for the user than a time when an acceleration is added. Targeting a plurality of users, the inventors of the present application have conducted an experiment on sensibility of nonlinearity of velocities of the input apparatus and the pointer while making a comparison between the planar-operation-type mouse and the 3-dimensional operation input apparatus. The result showed that most users are more sensible to nonlinearity when using the 3-dimensional operation input apparatus than when using the planar-operation-type mouse. This is considered to be because, as compared to the planar-operation-type input apparatus, the 3-dimensional operation input apparatus is operated while being aimed at a screen as if to directly input to the screen information on a movement of the input apparatus, that is, as if using a laser pointer. 
     On the other hand, a result of a similar user test showed that most users had been unable to recognize the linearity when operating the input apparatus at an extremely low velocity. In this case, most users were only able to recognize a tendency of a qualitative movement, that is, a fact that the pointer moves fast when the input apparatus is moved fast or the pointer moves slowly when the input apparatus is moved slowly. 
     Moreover, irrespective of a velocity range of the input apparatus, the users as test targets had high perception sensitivity to following capability with respect to sharp acceleration and deceleration, and had been able to recognize even a 10 ms-order delay, for example. In addition, a result that an operational feeling becomes more favorable as the following capability during an operation becomes higher was also obtained. 
     SUMMARY 
     In view of the circumstances as described above, an object is to provide an input apparatus, a control apparatus, a control system including those apparatuses, and a control method therefor with which a user can feel a linearity between a movement of the input apparatus and that of a pointer and an accurate pointing operation is possible. 
     According to an embodiment, there is provided an input apparatus controlling a movement of a pointer on a screen, including a casing, a movement signal output means, a gain means, a control means, and a transmission means. 
     The movement signal output means detects a movement of the casing and outputs a signal of a velocity-related value that is related to a velocity of the casing. 
     The gain means obtains a pointer velocity value as a velocity value for moving the pointer on the screen by multiplying the output velocity-related value by a gain. 
     The control means variably controls the gain in a first range in which the output velocity-related value ranges from a first threshold value to a second threshold value larger than the first threshold value, and controls the gain to be constant in a second range in which the output velocity-related value exceeds the second threshold value. 
     The transmission means transmits information on the pointer velocity value obtained by the gain means. 
     In the embodiment, the gain is controlled variably in the first range as a relatively-low-velocity range in which the movement of the casing ranges from the first threshold value to the second threshold value and a user cannot recognize a linearity. Therefore, it becomes possible for the user to perform accurate pointing when the movement of the casing is in the relatively-low-velocity range. Moreover, the gain is controlled to be constant in the second range as a relatively-high-velocity range in which the velocity-related value from the movement signal output means exceeds the second threshold value. Accordingly, a movement of the input apparatus and a movement of the pointer correspond linearly in a range in which a velocity of the movement of the casing is relatively high, with the result that an operational feeling for the user is improved. 
     The velocity-related value is a velocity value or angular velocity value of the casing. Further, the velocity-related value is considered in an absolute value. 
     The movement signal output means includes a sensor, or a sensor and means for performing an operation based on a detection value detected by the sensor. Therefore, when the sensor is an acceleration sensor that detects an acceleration, the movement signal output means includes means for calculating a velocity value by an operation based on an acceleration value as a detection value and outputting it. When the sensor is an angular velocity sensor that detects an angular velocity, the movement signal output means obtains the velocity value based on an angular velocity value as the detection value. The detected angular velocity value can be used as the velocity value of the casing, and an angular acceleration value calculated by temporally differentiating the detected angular velocity value can be used as the acceleration value of the casing. 
     The first threshold value may be set to 0 or a value larger than 0. 
     The control means controls the gain so that the gain increases as the velocity-related value increases in the first range. The expression “so that the gain increases” refers to a case where the gain increases linear-functionally, by a multi-degree function of quadratic or more, stepwise, by a combination of at least two of the above, or various other ways to increase. The same holds true for the expression “gain increases” below. A multi-degree function of quadratic or more is not limited to a downwardly-convex function and may be an upwardly-convex function. 
     The control means controls the gain to be constant in a third range in which the output velocity-related value ranges from 0 to the first threshold value. As described above, since the movement of the pointer becomes linear in accordance with an operation at a start of the movement of the input apparatus (instant the input apparatus starts moving), the pointer starts moving smoothly. 
     The movement signal output means may output an acceleration value of the casing, and the control means may control the gain so that the gain increases as the acceleration value increases in the first range. 
     When the user starts moving the input apparatus or stops moving the input apparatus, that is, when the input apparatus moves at high acceleration, no accurate pointing is required. In the embodiment, the gain becomes more constant, that is, a relationship between the movement of the input apparatus and the movement of the pointer becomes more linear as the acceleration value of the input apparatus increases. Therefore, the pointer starts moving smoothly when the user starts moving the input apparatus at a high velocity, with the result that the user does not feel poor following capability of the pointer. 
     In the case of the variable gain, at the time of acceleration in particular, there may be users who feel poorness in the following capability. This is because, in terms of appearance, a response seems slow since the velocity of the pointer is slow in the low-velocity range. In this regard, for enhancing the following capability with respect to such sharp acceleration, the gain only needs to be controlled in accordance with a level of the acceleration. In other words, it is effective to change a velocity profile so as to obtain more linearity as the acceleration of the casing increases. 
     The acceleration value may be an acceleration value detected by the acceleration sensor or an acceleration value obtained by a calculation and from which gravity components and the like have been removed. The same holds true for the following embodiments. 
     The movement signal output means outputs an acceleration value of the casing, and the control means changes a change rate of the gain in the first range in accordance with a change in the acceleration value. When the gain is linear, the change rate is a tilt thereof. When the gain is a multi-degree curve, the gain is a differential value. At least one of the first threshold value and the second threshold value may be changed. Moreover, as a result of the embodiment, it is also possible to change the change rate of the gain so that the relationship between the movement of the input apparatus and the movement of the pointer becomes more linear. 
     The input apparatus may further include a storage means for storing information on a plurality of velocity-related values that are temporally consecutive in the first range, and a sign judgment means for judging whether signs of the plurality of stored velocity-related values are the same. The control means includes a gain value storage means for storing a value of the gain in the first range and controls, when the signs of the plurality of velocity-related values are the same, the gain using a value obtained by adding a constant value to the stored gain value or multiplying the stored gain value by the constant value. When the signs of the plurality of stored velocity values are the same, a direction of the velocity has not changed during that period. Therefore, in this case, it is considered that the user is in midst of moving the pointer from a certain position on the screen to a different position relatively distant therefrom and that a coarse motion operation in which accurate pointing is not performed is being made. In the case of a coarse motion operation, by adding or multiplying the constant value, the relationship between the movement of the input apparatus and the movement of the pointer becomes more linear, with the result that an operational feeling for the user can be improved. 
     Alternatively, the control means may control the gain using the stored gain value and the acceleration value of the casing when the signs of the plurality of velocity-related values are the same. In other words, in the case of a coarse motion operation, by performing control so that the relationship between the movement of the input apparatus and the movement of the pointer becomes more linear as the acceleration value increases, an operational feeling for the user can be improved. 
     The control means may control a value of the gain to be constant when the value of the increased gain exceeds the constant gain. 
     The input apparatus may further include an adjustment means for adjusting at least one of a change rate of the gain in the first range, the first threshold value, the second threshold value, and a value of the gain in the second range. As the adjustment means, a mechanical switch or a static switch, for example, only needs to be provided to the input apparatus. Alternatively, the input apparatus only needs to include software including GUI as the adjustment means. When the input apparatus includes such software, image information or the like of that GUI only needs to be transmitted to a control apparatus communicating with the input apparatus. 
     The movement signal output means includes an acceleration sensor that detects an acceleration of the casing in a direction along a predetermined axis, and a velocity calculation means for calculating, as the velocity-related value, the velocity value of the casing in the direction along the predetermined axis of the casing by integrating the detected acceleration value. 
     Alternatively, the movement signal output means includes a first acceleration sensor that detects a first acceleration in a direction along a first axis, a second acceleration sensor that detects a second acceleration in a direction along a second axis different from the direction along the first axis, and a velocity calculation means for calculating, by an integration operation that is based on the first acceleration and the second acceleration, a first velocity value of the casing in the direction along the first axis and a second velocity value in the direction along the second axis. 
     Alternatively, the movement signal output means includes an output means for outputting an angular velocity value of the casing about the predetermined axis, and an obtainment means for obtaining the velocity value calculated based on the output angular velocity value as the velocity-related value. A case where the output means includes an angle sensor, a case where the output means includes an angular velocity sensor, or a case where the output means includes an angular acceleration sensor is conceivable. A geomagnetic sensor is used as the angle sensor, and an angular velocity value is obtained by differentiating an angle value as a detection value thereof. The output means only needs to output the angular velocity value. The angular acceleration sensor is constituted as a combination of a plurality of acceleration sensors. When the output means includes the angular acceleration sensor, an angular acceleration value as a detection value thereof is integrated for outputting an angular velocity value. 
     The movement signal output means includes a first acceleration sensor that detects a first acceleration in a direction along a first axis, a first output means for outputting a first angle-related value as a value related to a rotational angle of the casing about a second axis different from the direction along the first axis, and a first calculation means for calculating a first velocity value of the casing in the direction along the first axis as the velocity-related value based on the first acceleration value and the first angle-related value. 
     When a human being operates the input apparatus naturally, the operation is made by at least one of a rotation from a base of an arm, bending of an elbow, and a turn of a wrist. Therefore, generation of an acceleration inevitably leads to generation of an angular acceleration in the same direction as the acceleration. Moreover, the same holds true for the velocity, and generation of a velocity inevitably leads to generation of an angular velocity in the same direction. In other words, the acceleration and the angular acceleration are correlated, and the velocity and the angular velocity are correlated. In the embodiment, information on one of the acceleration value and the angle-related value is used as an adminicle of the other information. Accordingly, accuracy in calculating velocity values can be improved. Although the first velocity value regarding the first axis has been calculated in the embodiment, it is also possible to calculate a second velocity value regarding a second axis as in the next embodiment. 
     In this case, the movement signal output means may include a second acceleration sensor that detects a second acceleration in a direction along the second axis, a second output means for outputting a second angle-related value as a value related to a rotational angle of the casing about the first axis, and a second calculation means for calculating a second velocity value of the casing in the direction along the second axis as the velocity-related value based on the second acceleration value and the second angle-related value. The first axis and the second axis do not always need to be orthogonal. When the first axis and the second axis are not orthogonal, the first acceleration value and the second acceleration value can be converted into those on the two orthogonal axes by an operation that uses a trigonometric function. 
     The angle-related value (first or second angle-related value) is typically an angular velocity value, but may be an angle value or an angular acceleration value. 
     In the case of the present embodiment, the control means only needs to independently perform control using the same (or different) gain profile(s) regarding the first velocity value and the second velocity value. Alternatively, the following configuration is also possible. 
     The control means variably controls the gain in a range in which an operational value obtained based on the first velocity value and the second velocity value that have been calculated ranges from a third threshold value to a fourth threshold value larger than the third threshold value, and controls the gain to be constant in a range in which the operational value exceeds the fourth threshold value. 
     The operational value is a value obtained by a predetermined operational expression using the first velocity value and the second velocity value. The operational expression can be changed as appropriate. 
     The input apparatus further includes a comparison means for comparing the first velocity value and the second velocity value that have been calculated, and the control means controls the gain with respect to a larger one of the first velocity value and the second velocity value as a result of the comparison. Accordingly, a calculation amount can be reduced as compared to a case where the operational value is used as described above or the gain is controlled independently for the first velocity value and the second velocity value, for example. 
     According to an embodiment, there is provided a control apparatus controlling a movement of a pointer on a screen based on information on a detection value transmitted from an input apparatus including a casing, a detection means for detecting a movement of the casing, and a transmission means for transmitting the information on the detection value obtained by the detection means, the control apparatus including a reception means, a movement signal output means, a gain means, a control means, and a coordinate information generation means. 
     The reception means receives the information on the detection value. 
     The movement signal output means outputs a signal corresponding to a velocity-related value that is related to a velocity of the casing. 
     The gain means obtains a pointer velocity value as a velocity value for moving the pointer on the screen by multiplying the output velocity-related value by a gain. 
     The control means variably controls the gain in a first range in which the output velocity-related value ranges from a first threshold value to a second threshold value larger than the first threshold value, and controls the gain to be constant in a second range in which the output velocity-related value exceeds the second threshold value. 
     The coordinate information generation means generates coordinate information of the pointer on the screen that corresponds to the pointer velocity value obtained by the gain means. 
     The control apparatus may further include a determination means for determining a size of an icon on the screen and an adjustment means for adjusting, in accordance with the size of an icon determined by the determination means, at least one of a change rate of the gain in the first range, the first threshold value, the second threshold value, and a value of the gain in the second range. The icon used herein is an image on the screen  3  representing a function of a program, a program content, an execution command, a file content, and the like of a computer. In this case, a processor of the control apparatus mainly assumes the function of the adjustment means. 
     According to an embodiment, there is provided a control system controlling a movement of a pointer on a screen, including an input apparatus and a control apparatus. 
     The input apparatus includes a casing, a movement signal output means, a gain means, a control means, and a transmission means. The movement signal output means outputs a signal corresponding to a velocity-related value that is related to a velocity of the casing. The gain means obtains a pointer velocity value as a velocity value for moving the pointer by multiplying the output velocity-related value by a gain. The control means variably controls the gain in a first range in which the output velocity-related value ranges from a first threshold value to a second threshold value larger than the first threshold value, and controls the gain to be constant in a second range in which the output velocity-related value exceeds the second threshold value. The transmission means transmits information on the pointer velocity value obtained by the gain means. 
     The control apparatus includes a reception means and a coordinate information generation means. The reception means receives the transmitted information on the pointer velocity value. The coordinate information generation means generates coordinate information of the pointer on the screen that corresponds to the received pointer velocity value. 
     According to another embodiment, there is provided a control system in which an input apparatus includes a casing, a detection means for detecting a movement of the casing, and a transmission means for transmitting information on a detection value obtained by the detection means. A control apparatus includes a reception means for receiving the transmitted information on the detection value, a movement signal output means for outputting a signal corresponding to a velocity-related value that is related to a velocity of the casing based on the received information on the detection value, a gain means for obtaining a pointer velocity value as a velocity value for moving the pointer by multiplying the output velocity-related value by a gain, a control means for variably controlling the gain in a first range in which the output velocity-related value ranges from a first threshold value to a second threshold value larger than the first threshold value, and controlling the gain to be constant in a second range in which the output velocity-related value exceeds the second threshold value, and a coordinate information generation means for generating coordinate information of the pointer on the screen that corresponds to the pointer velocity value obtained by the gain means. 
     According to an embodiment, there is provided a control method including: detecting a movement of an input apparatus; outputting a signal corresponding to a velocity-related value that is related to a velocity of the input apparatus; variably controlling a gain for determining a pointer velocity value as a velocity value for moving a pointer on a screen, in a first range in which the output velocity-related value ranges from a first threshold value to a second threshold value larger than the first threshold value; controlling the gain to be constant in a second range in which the output velocity-related value exceeds the second threshold value; outputting the pointer velocity value by multiplying the output velocity-related value by the controlled gain; and generating coordinate information of the pointer on the screen that corresponds to the pointer velocity value. 
     According to an embodiment, there is provided a handheld apparatus controlling a movement of a pointer on a screen, including a casing, a display section, a movement signal output means, a gain means, and a control means. 
     The display section displays the screen. The movement signal output means detects a movement of the casing and outputs a signal of a velocity-related value that is related to a velocity of the casing. The gain means obtains a pointer velocity value as a velocity value for moving the pointer on the screen by multiplying the output velocity-related value by a gain. The control means variably controls the gain in a first range in which the output velocity-related value ranges from a first threshold value to a second threshold value larger than the first threshold value, and controls the gain to be constant in a second range in which the output velocity-related value exceeds the second threshold value. 
     Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  A diagram showing a control system according to an embodiment. 
         FIG. 2  A perspective diagram showing an input apparatus. 
         FIG. 3  A diagram schematically showing an internal structure of the input apparatus. 
         FIG. 4  A block diagram showing an electrical structure of the input apparatus. 
         FIG. 5  A diagram showing an example of a screen displayed on a display apparatus. 
         FIG. 6  A diagram showing a state where a user is holding the input apparatus  1 . 
         FIG. 7  Explanatory diagrams showing typical examples of ways of moving the input apparatus and ways a pointer moves on the screen accordingly. 
         FIG. 8  A perspective diagram showing a sensor unit. 
         FIG. 9  A flowchart showing an operation of the control system according to the embodiment. 
         FIG. 10  Graphs showing profiles of gain value(s) K x  and/or K y  of Equation (1) or (2). 
         FIG. 11  (A) is a graph showing a gain profile according to another embodiment. (B) is a graph showing a velocity profile obtained by the gain profile shown in (A). 
         FIG. 12  (A) is a graph showing a gain profile according to still another embodiment. (B) is a graph showing a velocity profile obtained by the gain profile shown in (A). 
         FIG. 13  (A) is a gain profile that increases linear-functionally from a 0 velocity value of the input apparatus to a high-velocity range. (B) is a pointer velocity profile obtained by the gain profile of (A). 
         FIG. 14  (A) is a graph showing a gain profile that is constant from the 0 velocity value of the input apparatus to the high-velocity range.  FIG. 14(B)  is a pointer velocity profile obtained by the gain profile of  FIG. 14(A) . 
         FIG. 15  A flowchart showing an operation of the control system in a case where the gain profile shown in  FIG. 12(A)  is used. 
         FIG. 16  A flowchart showing an operation of the control system in a case where a control apparatus carries out main operations. 
         FIG. 17  A flowchart showing an operation of the control system according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     As described above, according to the embodiments, a user can feel a linearity between a movement of an input apparatus and that of a pointer, and an accurate pointing operation becomes possible. 
     Hereinafter, embodiments will be described with reference to the drawings. 
       FIG. 1  is a diagram showing a control system according to an embodiment. A control system  100  includes a display apparatus  5 , a control apparatus  40 , and an input apparatus  1 . 
       FIG. 2  is a perspective diagram showing the input apparatus  1 . The input apparatus  1  is of a size that a user is capable of holding. The input apparatus  1  includes a casing  10  and operation sections including two buttons  11  and  12  provided at an upper portion of the casing  10 , a rotary wheel button  13 , and the like, for example. The button  11  disposed closer to the center of the upper portion of the casing  10  functions as a left button of a mouse as an input device for a PC, for example, and the button  12  adjacent to the button  11  functions as a right button of a mouse. 
     For example, a “drag and drop” operation may be executed by moving the input apparatus  1  while pressing the button  11 , a file may be opened by double-clicking the button  11 , and a screen  3  may be scrolled by the wheel button  13 . Locations of the buttons  11  and  12  and the wheel button  13 , a content of a command issued, and the like can arbitrarily be changed. 
       FIG. 3  is a diagram schematically showing an internal structure of the input apparatus  1 .  FIG. 4  is a block diagram showing an electrical structure of the input apparatus  1 . 
     The input apparatus  1  includes a sensor unit  17 , a control unit  30 , and batteries  14 . 
       FIG. 8  is a perspective diagram showing the sensor unit  17 . 
     The sensor unit  17  includes an acceleration sensor unit  16  for detecting accelerations in different angles such as along two orthogonal axes (X′ axis and Y′ axis). Specifically, the acceleration sensor unit  16  includes two sensors, that is, an acceleration sensor  16  for a yaw direction and an acceleration sensor  162  for a pitch direction. 
     The sensor unit  17  further includes an angular velocity sensor unit  15  for detecting angular accelerations about the two orthogonal axes. Specifically, the angular velocity sensor unit  15  includes two sensors, that is, an angular velocity sensor  151  for a yaw direction and an angular velocity sensor  152  for a pitch direction. The acceleration sensor unit  16  and the angular velocity sensor unit  15  are packaged and mounted on a circuit board  25 . 
     As each of the angular velocity sensors  151  and  152  for the yaw and pitch directions, respectively, a vibration gyro sensor for detecting Coriolis force in proportion to an angular velocity is used. As each of the acceleration sensors  161  and  162  for the X- and Y-axis directions, respectively, any sensor such as a piezoresistive sensor, a piezoelectric sensor, or a capacitance sensor may be used. The angular velocity sensor  151  or  152  is not limited to the vibration gyro sensor, and a rotary top gyro sensor, a ring laser gyro sensor, a gas rate gyro sensor, and the like may also be used. 
     In descriptions on  FIGS. 2 and 3 , a longitudinal direction of the casing  10  is referred to as Z′ direction, a thickness direction of the casing  10  is referred to as X′ direction, and a width direction of the casing  10  is referred to as Y′ direction for convenience. In this case, the sensor unit  17  is incorporated into the casing  10  such that a surface of the circuit board  25  on which the acceleration sensor unit  16  and the angular velocity sensor unit  15  are mounted becomes substantially parallel to an X′-Y′ plane. As described above, the sensor units  16  and  15  each detect physical amounts with respect to the two axes, that is, the X axis and the Y axis. In the specification, a coordinate system that moves along with the input apparatus  1 , that is, a coordinate system fixed to the input apparatus  1  is expressed using the X′ axis, Y′ axis, and Z′ axis, whereas a coordinate system stationary on earth, that is, an inertial coordinate system is expressed using the X axis, Y axis, and Z axis. Further, in descriptions below, with regard to a movement of the input apparatus  1 , a rotational direction about the X′ axis is sometimes referred to as pitch direction, a rotational direction about the Y′ axis is sometimes referred to as yaw direction, and a rotational direction about the Z′ axis (roll axis) direction is sometimes referred to as roll direction. 
     The control unit  30  includes a main substrate  18 , an MPU  19  (Micro Processing Unit) (or CPU) mounted on the main substrate  18 , a crystal oscillator  20 , a transceiver  21 , and an antenna  22  printed on the main substrate  18 . 
     The MPU  19  includes a built-in volatile or nonvolatile memory requisite therefor. The MPU  19  is input with a detection signal from the sensor unit  17 , an operation signal from the operation sections, and the like, and executes various kinds of operational processing in order to generate predetermined control signals in response to those input signals. The memory may be provided separate from the MPU  19 . 
     Typically, the sensor unit  17  outputs analog signals. In this case, the MPU  19  includes an A/D (Analog/Digital) converter. Alternatively, the sensor unit  17  may be a unit that includes the A/D converter. 
     The MPU  19  alone or the MPU  19  and the crystal oscillator  20  constitutes/constitute a processing unit. 
     The transceiver  21  (transmission means) transmits, as RF radio signals, a control signal generated in the MPU  19  to the control apparatus  40  via the antenna  22 . The transceiver  21  is also capable of receiving various signals transmitted from the control apparatus  40 . 
     The crystal oscillator  20  generates clocks and supplies them to the MPU  19 . As the batteries  14 , dry cell batteries, rechargeable batteries, and the like are used. 
     The control apparatus  40  includes an MPU  35  (or CPU), a RAM  36 , a ROM  37 , a video RAM  41 , a display control section  42 , an antenna  39 , and a transceiver  38 . 
     The transceiver  38  receives the control signal transmitted from the input apparatus  1  via the antenna  39  (reception means). The transceiver  38  is also capable of transmitting various predetermined signals to the input apparatus  1 . The MPU  35  analyzes the control signal and executes various kinds of operational processing. The display control section  42  mainly generates screen data to be displayed on the screen  3  of the display apparatus  5  under control of the MPU  35 . The video RAM  41  as a working area of the display control section  42  temporarily stores the generated screen data. 
     The control apparatus  40  may be an apparatus dedicated to the input apparatus  1 , or may be a PC or the like. The control apparatus  40  is not limited to the apparatus dedicated to the input apparatus  1 , and may be a computer integrally formed with the display apparatus  5 , audiovisual equipment, a projector, a game device, a car navigation system, or the like. 
     Examples of the display apparatus  5  include a liquid crystal display and an EL (Electro-Luminescence) display, but are not limited thereto. The display apparatus  5  may alternatively be an apparatus integrally formed with a display and capable of receiving television broadcasts and the like, or an apparatus in which such a display and the control apparatus  40  are integrated. 
       FIG. 5  is a diagram showing an example of the screen  3  displayed on the display apparatus  5 . UIs such as icons  4  and a pointer  2  are displayed on the screen  3 . The icons are images on the screen  3  representing functions of programs, program contents, execution commands, file contents, and the like of the computer. It should be noted that on the screen  3 , the horizontal direction is referred to as X-axis direction and the vertical direction is referred to as Y-axis direction. 
       FIG. 6  is a diagram showing a state where a user is holding the input apparatus  1 . As shown in  FIG. 6 , the input apparatus  1  may include, in addition to the buttons  11 ,  12 , and  13 , various operation buttons such as those provided to a remote controller for operating a television or the like and a power supply switch, for example. When the user moves the input apparatus  1  in the air or operates the operation sections while holding the input apparatus  1  as shown in the figure, input information thereof is output to the control apparatus  40 , and the control apparatus  40  controls the UI. 
     Next, a description will be given on typical examples of ways of moving the input apparatus  1  and ways the pointer  2  moves on the screen  3  accordingly.  FIG. 7  are explanatory diagrams therefor. 
     As shown in  FIGS. 7(A) and 7(B) , the user holds the input apparatus  1  so as to aim the buttons  11  and  12  side of the input apparatus  1  at the display apparatus  5  side. The user holds the input apparatus  1  so that a thumb is located on an upper side and a pinky is located on a lower side as in handshakes. In this state, the circuit board  25  of the sensor unit  17  (see  FIG. 8 ) is close to being in parallel with the screen  3  of the display apparatus  5 , and the two axes as detection axes of the sensor unit  17  respectively correspond to the horizontal axis (X axis) and the vertical axis (Y axis) on the screen  3 . Hereinafter, the position of the input apparatus  1  as shown in  FIGS. 7(A) and 7(B)  will be referred to as reference position. 
     As shown in  FIG. 7(A) , in the reference position, the user swings a wrist or an arm in the vertical direction, that is, the pitch direction. At this time, the acceleration sensor  162  for the Y′-axis direction detects an acceleration a y  in the Y′-axis direction, and the angular velocity sensor  152  for the pitch direction detects an angular velocity ω θ  about the X′ axis. Based on those detection values, the control apparatus  40  controls display of the pointer  2  so that the pointer  2  moves in the Y-axis direction. 
     Meanwhile, as shown in  FIG. 7(B) , in the reference position, the user swings the wrist or the arm in the lateral direction, that is, the yaw direction. At this time, the acceleration sensor  161  for the X′-axis direction detects an acceleration a x  in the X′-axis direction, and the angular velocity sensor  151  for the yaw direction detects an angular velocity ω ψ  about the Y′ axis. Based on those detection values, the control apparatus  40  controls display of the pointer  2  so that the pointer  2  moves in the X-axis direction. 
     Next, an operation of the control system  100  structured as described above will be described.  FIG. 9  is a flowchart showing the operation. 
     Power of the input apparatus  1  is turned on. By the user pressing the power supply switch or the like provided to the input apparatus  1  or the control apparatus  40 , for example, the power of the input apparatus  1  is turned on. When the power is turned on, biaxial angular velocity signals are output from the angular velocity sensor unit  15 . The MPU  19  obtains a first angular velocity value ω ψ  and a second angular velocity value ω θ  from the biaxial angular velocity signals (Step  101 ). 
     Further, upon turning on the power of the input apparatus  1 , biaxial acceleration signals are output from the acceleration sensor unit  16 . The MPU  19  obtains a first acceleration value a x  and a second acceleration value a y  from the biaxial acceleration signals (Step  102 ). The signals on the acceleration values are signals corresponding to the position of the input apparatus  1  at a point when the power is turned on (hereinafter, referred to as initial position). Hereinafter, the initial position will be described as being the reference position unless stated otherwise as will be described later. It should be noted that the MPU  19  typically carries out Steps  101  and  102  in sync every predetermined clock cycle. 
     It should be noted that in  FIG. 9  and the like, the acceleration signals are obtained by the acceleration sensor unit after the angular velocity signals are obtained by the angular velocity sensor unit. However, the order is not limited thereto, and the angular velocity signals may be obtained after the acceleration signals are obtained, or the acceleration signals and the angular velocity signals may be obtained in parallel (at the same time) (the same holds true for  FIGS. 15, 16, and 17  below). 
     Based on the acceleration values (a x , a y ) and the angular velocity values (ω ψ , ω θ ), the MPU  19  calculates velocity values (first velocity value V x , second velocity value V y ) by a predetermined operation (Step  103 ). The first velocity value V x  is a velocity value in a direction along the X axis and the second velocity value V y  is a velocity value in a direction along the Y axis. A velocity value calculation method will be described later in detail. In this point, at least the sensor unit  17  alone or the MPU  19  and the sensor unit  17  functions/function as a movement signal output means for outputting a velocity-related value as a movement signal of the input apparatus  1 . In this embodiment, the velocity value will be exemplified as the velocity-related value. 
     As the method of calculating the velocity values (V x , V y ), in this embodiment, the MPU  19  divides the acceleration values (a x , a y ) by angular acceleration values (Δω ψ , Δω θ ) to thus obtain radius gyrations (R ψ , R θ ) of the movement of the input apparatus  1 . In this case, the velocity values (V x , V y ) can be calculated by multiplying the radius gyrations (R ψ , R θ ) by the angular velocity values (ω ψ , ω θ ). The radius gyrations (R ψ , R θ ) may also be obtained by dividing acceleration change rates (Δa x , Δa y ) by angular acceleration change rates (Δ(Δω ψ ), Δ(Δω θ )). 
     By calculating the velocity values by the calculation method described above, an operational feeling of the input apparatus  1  that matches an intuition of the user can be obtained, and moreover, the movement of the pointer  2  on the screen  3  also accurately matches the movement of the input apparatus  1 . 
     It should be noted that the velocity values (V x , V y ) do not always need to be calculated by the calculation method above. For example, the MPU  19  may calculate the velocity values by, for example, integrating the acceleration values (a x , a y ) while using the angular velocity values (ω ψ , ω θ ) as an adminicle for the integration operation. Alternatively, it is also possible for the velocity values (V x , V y ) to be calculated by simply integrating the acceleration values (a x , a y ). Alternatively, the detected angular velocity values (ω ψ , ω θ ) may be used as they are as the velocity values (V x , V y ) of the casing. It is also possible to obtain angular acceleration values (Δω ψ , Δω θ ) by temporally differentiating the detected angular velocity values (ω ψ , ω θ ), and use them as the acceleration values of the casing. 
     As expressed in Equations (1) and (2) below, the MPU  19  multiplies the calculated velocity values (V x , V y ) by predetermined gain values (K x , K y ) to thus obtain velocity values (V x ′, V y ′) (pointer velocity values) for moving the pointer on the screen (Step  104 ).
 
V x ′=K x *V x    (1)
 
V y ′=K y *V y    (2)
 
     The MPU  19  transmits information on the obtained pointer velocity values (V x ′, V y ′) to the control apparatus  40  via the transceiver  21  and the antenna  22  (Step  105 ). 
     The MPU  35  of the control apparatus  40  receives the information on the pointer velocity values (V x ′, V y ′) via the antenna  39  and the transceiver  38  (Step  106 ). The input apparatus  1  transmits the pointer velocity values (V x ′, V y ′) every predetermined clocks, that is, per unit time, so the control apparatus  40  can receive this and obtain displacement amounts in the X- and Y-axis directions per unit time. 
     The MPU  35  generates coordinate values (X(t), Y(t)) of the pointer  2  on the screen  3  that correspond to the obtained displacement amounts in the X- and Y-axis directions per unit time by Equations (3) and (4) below (Step  107 ). Based on the generated coordinate values, the MPU  35  controls display so that the pointer  2  moves on the screen  3  (Step  108 ) (coordinate information generation means).
 
X(t)=X(t−1)+V x ′  (3)
 
Y(t)=Y(t−1)+V y ′  (4)
 
       FIG. 10(A)  is a graph showing a profile of the gain value(s) K x  and/or K y  of Equation (s) (1) and/or (2) above. In  FIG. 10(A) , an abscissa axis represents the velocity value(s) V x  and/or V y  of the input apparatus  1  obtained in Step  103 , and an ordinate axis represents the gain value(s) K x  and/or K y . In other words, the gain value(s) K x  and/or K y  are functions of the velocity value(s) V x  and/or V y , respectively. 
     In descriptions below, unless limitedly stated otherwise, the abscissa axis represents one of the velocity values V x  and V y  and the ordinate axis represents the gain value K with respect to that one of the velocity values V x  and V y  in the gain profile as shown in  FIG. 10(A) . 
     In the example shown in  FIG. 10(A) , the MPU  19  functions as a controls means for variably controlling the gain value K in a range from a threshold value v 1  (first threshold value) to a threshold value v 2  (second threshold value) (first range) in which the input apparatus  1  is in a low-velocity range, and controlling the gain value K to be constant in a range exceeding the second threshold value v 2  (second range). 
     When resolution performance of the velocity value on the abscissa axis is expressed by an absolute value of ±128 (8 bits), the threshold value v 1  is set to be 4 to 12 or 6 to 10, typically 8. Moreover, the threshold value v 2  is set to be 10 to 20 or 12 to 16, typically 14. However, the threshold values v 1  and v 2  are not limited to those ranges and can be changed as appropriate. The resolution performance of the velocity value on the abscissa axis may be 8 bits or less or larger than 8 bits. 
     A velocity equal to or smaller than the threshold value v 2  typically becomes 5 cm/s or less when converted into an actual velocity of the input apparatus  1 , but settings can be changed as appropriate to 10 cm/s or less, 3 cm/s or less, or other ranges (e.g., 2 go 4 cm/s). A relatively-high-velocity range of the input apparatus  1  refers to a case exceeding 10 cm/s or a case exceeding 20 cm/s, for example, but settings thereof can also be changed as appropriate. 
       FIG. 10(B)  is a graph showing a profile of the velocity value for moving the pointer  2  on the screen  3 , that is obtained by the gain profile shown in  FIG. 10(A)  (hereinafter, referred to as velocity profile). As in  FIG. 10(A) , the abscissa axis represents the velocity value(s) V x  and/or V y  of the input apparatus  1  obtained in Step  103 . A graph obtained by temporally differentiating the velocity profile of  FIG. 10(B)  becomes the graph of the gain profile of  FIG. 10(A) . The gain is a value with the velocity value V x  or V y  of the input apparatus  1  as an input and the pointer velocity value (V x ′, V y ′) as an output. 
     As shown in  FIG. 10(B) , when the velocity value V x  or V y  of the input apparatus  1  is 0, a gain value K 1  is, for example, 0.2 to 0.4, that is, an output/input is set to be 0.2 to 0.4, though not limited to this range. A constant gain value K 2  is set to 1 but may be other values. This is because as long as the gain value K 2  is a constant value, the velocity value of the input apparatus  1  and the pointer velocity value correspond linearly. 
     The MPU  19  only needs to store functions expressing the gain profile in the memory and use the functions to dynamically calculate the pointer velocity values. Alternatively, a lookup table generated based on the gain profile, that shows a correspondence between the velocity value V x  or V y  of the input apparatus  1  and the pointer velocity value, may be stored in the memory in advance. The same holds true for other gain profiles to be described later ( FIGS. 11(A) and 12(A) ). 
     As described above, the gain value K is controlled variably in a relatively-low-velocity range in which the velocity value V x  or V y  of the input apparatus  1  is equal to or smaller than the threshold value v 2 . For example, in this embodiment, the gain value K is set to increase as the velocity value V x  or V y  of the input apparatus  1  increases in the range in which the velocity value of the input apparatus  1  ranges from v 1  to v 2 . Therefore, it becomes possible for the user to perform accurate pointing in the range in which the velocity of the movement of the input apparatus is relatively low. Moreover, the gain value K is controlled to be constant in the relatively-high-velocity range in which the velocity value V x  or V y  of the input apparatus  1  exceeds the threshold value v 2 . Therefore, the movement of the input apparatus  1  and that of the pointer  2  correspond linearly in the range in which the velocity value V x  or V y  of the input apparatus  1  is relatively high, with the result that an operational feeling for the user is improved. 
     To put is the other way around, the range in which the velocity value V x  or V y  of the input apparatus  1  is relatively low is a range in which, even when the velocity profile is not linear, the user cannot judge whether it is linear or not. Specifically, that range is typically 5 cm/s or less as described above. 
     Further, the MPU  19  controls the gain to be constant in a range in which the velocity value of the input apparatus  1  ranges from 0 to the threshold value v 1  (third range). Since the movement of the pointer  2  becomes linear in accordance with an operation at a start of the movement of the input apparatus  1  (instant the input apparatus starts moving) as described above, the pointer  2  starts moving smoothly. 
     Here, in the typical example of  FIG. 10(A) , the gain value K in the range from the threshold value v 1  to the threshold value v 2  increases linear-functionally. Instead, a case of an increase by a multi-degree function of quadratic or more, a case of a stepwise increase, an increase by a combination of at least two of the above, or other ways to increase is also possible. The multi-degree function of quadratic or more is of course not limited to a downwardly-convex function, and may be an upwardly-convex function or a combination of those. The same holds true for the case of the multi-degree function of quadratic or more hereinbelow. 
       FIG. 11(A)  is a graph showing a gain profile according to another embodiment. In this gain profile, the threshold value v 1  shown in  FIG. 10(A)  is set to 0. Due to such a gain profile, a velocity profile shown in  FIG. 11(B)  increases smoothly from a 0 velocity value of the input apparatus  1 . Accordingly, the user does not feel a stress in the low-velocity range. 
     Moreover, in the gain profile shown in  FIG. 11(A) , a function from v 1  (=0) to v 2  is a multi-degree function of quadratic or more. However, this part may be a straight line as shown in  FIG. 10(A) . 
       FIG. 12(A)  is a graph showing a gain profile according to still another embodiment.  FIG. 12(B)  is a graph showing a velocity profile obtained by the gain profile shown in  FIG. 12(A) . 
     In this example, the gain profile is set based on the acceleration value of the input apparatus  1 , and in a range from the threshold value v 1  (=0) to the threshold value v 2 , the gain profile moves farther away from a gain profile that is located at the very bottom and indicated by a thick line F to come closer to 1 (or vicinity of 1) as indicated by broken lines as the acceleration value of the input apparatus increases. In other words, the threshold value v 2  shifts more to the low-velocity side as the acceleration value increases. 
     The threshold value v 1  may be a value other than 0. Although the gain in the range from the threshold value v 1  (=0) to the threshold value v 2  is a multi-degree function of quadratic or more, it may instead be a straight line. 
     The MPU  19  sets an operational value obtained based on the gain value K corresponding to the velocity values (V x , V y ) (previous gain value K) (first gain value) and functions (f(a xi ), f(a yi )) of acceleration values (a xi , a yi ) obtained by differentiating the velocity values V x , V y , as a new gain value K (second gain value) in place of the previous gain value K. 
     Hereinafter, the acceleration value a xi  or a yi  may simply be referred to as acceleration value a i , and the function f(a xi ) or f(a yi ) may simply be referred to as f(a i ). 
     The function f(a i ) can be made a function that increases as the acceleration value a i  increases. The way it increases is linear-functionally, by a multi-degree function of quadratic or more, stepwise, by a combination of at least two of the above, or by various other ways. The function f(a i ) only needs to be set while considering a balance between awkwardness of a user in operating the input apparatus  1  at a high acceleration and operability of accurate pointing through a user test, for example. 
     The operational value is a value obtained by adding the function f(a i ) to the previous gain value K or multiplying the previous gain value K by the function f(a i ).  FIG. 12(A)  shows a case where the operation value is obtained by adding the function f(a i ) to the previous gain value K. Accordingly, the gain profile as shown in  FIG. 12(A)  can be obtained. In other words, as indicated by broken lines, the gain value K approaches 1 (or vicinity of 1) from a gain value indicated by a thick line F as the acceleration value a i  increases. In other words, the threshold value v 2  shifts more to the low-velocity side as the acceleration value increases. 
     The function f(a i ) may be a function that decreases as the acceleration value a i  increases. In this case, the operational value can be obtained by dividing the previous gain value K by the function f(a i ). 
     Moreover, it is also possible to adopt a method of registering relationships among velocity values, acceleration values, and gain values in a table in advance and obtaining a corresponding gain value based on a velocity value and an acceleration value that have been detected. 
       FIG. 15  is a flowchart showing an operation of the control system  100  in a case where the gain profile shown in  FIG. 12(A)  is used. 
     Processes of Steps  201  to  203 a are the same as those of Steps  101  to  103  of  FIG. 9 . In Step  203 b, the MPU  19  obtains gain values (K x , K y ) that correspond to the velocity values (V x , V y ) calculated in Step  203 a. 
     In Step  204 , the MPU  19  differentiates the velocity values (V x , V y ) to obtain acceleration values (a xi , a yi ) of the input apparatus  1  in the X- and Y-axis directions. By using the acceleration values (a xi , a yi ) obtained by the differentiation operation, the control system  100  can recognize the movement of the input apparatus  1  more accurately than in the case where the detection values (a x , a y ) of the acceleration sensor unit  16  are used. This is because, as described above, the velocity values (V x , V y ) obtained based on the acceleration values (a x , a y ) and the angular velocity values (ω ψ , ω θ ) are differentiated. 
     The MPU  19  calculates a function f(a i ) (=f(a xi ), f(a yi )) from the obtained acceleration value a i  (=(a xi , a yi )) (Step  205 ). Upon calculating the function f(a i ), the MPU  19  calculates a new gain value (operational value) based on the gain K and the function f(a i ) (Step  206 ). Here, the new gain value K′ is K′=K+f(a i ) as described above, or may be K′=K*f(a i ). 
     Here, when the gain value K (=K′) obtained by the operation above exceeds the constant gain value K 2 , the MPU  19  only needs to set a maximum value of the gain value K to K 2 . 
     When the user starts moving the input apparatus  1  or stops moving the input apparatus  1 , that is, when the input apparatus  1  moves at a high acceleration, no accurate pointing is required. According to the gain profile as shown in  FIG. 12(A) , the gain value K becomes more constant, that is, a relationship between the movement of the input apparatus  1  and the movement of the pointer  2  becomes more linear as the acceleration value a i  of the input apparatus increases. For example, the threshold values v 1  and v 2  do not exist when the acceleration value a i  has become a certain value or more, and the gain profile becomes linear like the gain value K 2 . Therefore, the pointer  2  starts moving smoothly when the user starts moving the input apparatus  1  at a high velocity, with the result that the user does not feel poor following capability of the pointer. 
     In the case of the gain profiles as shown in  FIGS. 10(A) and 11(A) , at the time of acceleration in particular, there may be users who feel poorness in the following capability. This is because, in terms of appearance, a response seems slow since the velocity of the pointer  2  is slow in the low-velocity range. In this regard, for enhancing the following capability with respect to such sharp acceleration, the gain only needs to be controlled in accordance with a level of the acceleration. In other words, it is effective to change a velocity profile so as to obtain more linearity as the acceleration of the casing increases. 
     Processes of Steps  207  to  211  are the same as those of Steps  104  to  108  of  FIG. 9 . 
     The following configuration is also possible as another embodiment of the gain profiles described above. 
     For example, in  FIG. 10(A), 11(A) , or  12 (A), the MPU  19  may change a change rate of the gain value K in the range from the threshold value v 1  to the threshold value v 2  in accordance with the acceleration value a i . When the gain is linear, the change rate is a tilt thereof. When the gain is a multi-degree curve, the gain is a differential value. At least one of the threshold values v 1  and v 2  may be changed. It is also possible to change, by changing at least one of the threshold values v 1  and v 2 , the change rate of the gain so that the relationship between the movement of the input apparatus  1  and the movement of the pointer becomes more linear. 
     Alternatively, the MPU  19  may change the constant gain value K in the range in which the velocity value of the input apparatus  1  exceeds the threshold value v 2  in accordance with the acceleration value a i . For example, it is also possible for the gain value K to approach, from a first value as a constant value, a second value as a constant value larger than the first value as the acceleration value a i  increases. The first value and the second value may be 1 or values other than 1. 
     Here, regarding the gain profile shown in  FIG. 10(A), 11(A) , or  12 (A), the MPU  19  only needs to control the gain with respect to the velocity values (V x , V y ) in the X- and Y-axis directions based on the gain profile. In this case, the gain profile may differ between the X- and Y-axis directions. For example, one of the gain profiles shown in  FIGS. 10(A) to 12(A)  may be used for the X axis whereas a gain profile different from that for the X axis out of those shown in  FIGS. 10(A) to 12(A)  may be used for the Y axis. 
     Alternatively, the MPU  19  may variably control the gain in a range in which an operational value obtained based on the velocity values (V x , V y ) calculated in Step  103  or  203  ranges from a third threshold value to a fourth threshold value larger than the third threshold value, and control the gain to be constant in a range in which the operational value exceeds the fourth threshold value. In this case, the third threshold value may either be v 1  (first threshold value) or different from v 1 . Moreover, the fourth threshold value may either be v 2  (second threshold value) or different from v 2 . 
     The operational value obtained based on the velocity values (V x , V y ) is a value obtained by, for example, V x +V y  or (V x   2 +V y   2 ) 1/2 . The operational value may alternatively be a value obtained by an expression other than those operational expressions. 
     Alternatively, the MPU  19  may compare (absolute values of) the velocity values V x  and V y  calculated in Step  103  or  203  (comparison means) and use a larger one of the values as a representative value. Accordingly, a calculation amount can be reduced as compared to the case of using the operational value as described above or the case where the gain is controlled independently for the X axis and the Y axis. 
     In  FIG. 9 , the input apparatus  1  has carried out main operations to calculate the pointer velocity values (V x ′, V y ′). In an embodiment shown in  FIG. 16 , the control apparatus  40  carries out the main operations. 
     As shown in  FIG. 16 , processes of Steps  301  and  302  are the same as those of Steps  101  and  102 . The input apparatus  1  transmits to the control apparatus  40  information on detection values that are biaxial acceleration values and biaxial angular velocity values output from the sensor unit  17 , for example (Step  303 ). The MPU  35  of the control apparatus  40  receives the information on the detection values (Step  304 ) and executes processes the same as those of Steps  103 ,  104 ,  107 , and  108  (Steps  305  to  308 ). 
     Also in the flowchart shown in  FIG. 15 , it is possible for the control apparatus  40  to execute the main calculations in the same manner as the processing of  FIG. 16 . In this case, it is only necessary that, in  FIG. 16 , the input apparatus  1  execute Steps  201  and  202  and the control apparatus  40  execute Steps  203  to  207 ,  210 , and  211 . 
       FIG. 17  is a flowchart showing an operation of the control system  100  according to another embodiment. 
     Processes of Steps  401 ,  402 ,  403 a,  403 b, and  404  are the same as those of Steps  201 ,  202 ,  203 a,  204 b, and  204 . 
     In Step  405 , the MPU  19  stores a plurality of temporally-consecutive velocity values (V x , V y ) in the memory. In this case, a ring buffer or a FIFO (First In First Out) is used as the memory, but is not limited thereto. The number of samples of the velocity values (V x , V y ) is typically about 5 to 10, but since it varies depending on a clock frequency of the MPU  19 , it only needs to be set as appropriate. 
     Processes of Steps  406  and  407  are the same as those of Steps  205  and  206 . 
     In Step  408 , the MPU  19  judges whether signs of the plurality of consecutive velocity values (V x , V y ) stored in the memory are the same (sign judgment means). If the signs are the same, a direction of the velocity of the input apparatus  1  has not changed during that period. In this case, it is considered that the user is in midst of moving the pointer  2  from a certain position on the screen  3  to a different position relatively distant therefrom, that is, a coarse motion operation in which accurate pointing is not performed is being made. Therefore, in this case, for the pointer velocity values to become more linear, the MPU  19  adds a constant C to the gain value K (=(K x , K y )) calculated in Step  407  to thus calculate a new gain value K (Step  409 ). The constant C can be set as appropriate. 
     By adding a constant value in the processing as described above, the relationship between the movement of the input apparatus and the movement of the pointer becomes more linear, with the result that an operational feeling for the user can be improved. 
     However, for preventing the gain value K from exceeding K 2  even when added with the constant C, the MPU  19  monitors whether the gain value K exceeds K 2  (Steps  410  and  412 ). When the gain value K exceeds K 2 , the latest gain value K is assumed to be K 2  as the constant value (Steps  411  and  413 ). 
     On the other hand, when at least one of the consecutive velocity values (V x , V y ) has a sign different from those of other velocity values in Step  408 , it is considered that a micromotion operation in which accurate pointing is performed is being made. In this case, the constant C is not added to the gain value K. 
     Processes of Steps  414  to  418  are the same as those of Steps  207  to  211 . 
     It should be noted that in the judgment processing of Step  408 , the MPU  19  typically advances to Step  409  when the signs of V x  and V y  are the same. However, it is also possible for the MPU  19  to apply, when the sign of one of V x  and V y  is the same, Step  409  to only the velocity value with the same sign out of the velocities on the X axis and the Y axis. 
     Moreover, in Step  409 , it is also possible to calculate a new gain value K by multiplying the gain value K (=(K x , K y )) calculated in Step  407  by a certain constant. The processing as described above also bears the same effect as that described above. 
     It is also possible for the MPU  19  not to execute Step  407  and execute the judgment processing of Step  408  after Step  406 . In this case, the MPU  19  may execute Step  407  when judged YES in Step  408  and use the fixed gain profile shown in  FIG. 10(A) or 11(A)  when judged NO. Accordingly, in the case of a coarse motion operation, the relationship between the movement of the input apparatus  1  and the movement of the pointer  2  becomes more linear as the acceleration value increases, with the result that an operational feeling for the user can be improved. 
     Processes of Steps  403  to  414 ,  417 , and  418  shown in  FIG. 17  may also be executed by the control apparatus  40  in the same manner as the processing shown in  FIG. 16 , for example. 
       FIGS. 13 and 14  show reference examples of a gain profile. 
     A gain profile shown in  FIG. 13(A)  is a profile that increases linear-functionally from a 0 velocity value of the input apparatus to a high-velocity range.  FIG. 13(B)  shows a pointer velocity value obtained by the gain profile of  FIG. 13(A) . In this case, since the velocity value of the input apparatus and the pointer velocity value are nonlinear, the user feels awkward when using the 3-dimensional operation input apparatus. 
     A gain profile shown in  FIG. 14(A)  is constant from the 0 velocity value of the input apparatus to the high-velocity range. In this case,  FIG. 14(B)  shows a pointer velocity value obtained by the gain profile of  FIG. 14(A) . In this case, since the velocity profile becomes linear throughout all ranges, it becomes difficult to perform accurate pointing in the low-velocity range. 
     A function of adjusting at least one of the change rate of the gain (tilt etc.), the threshold value v 1 , the threshold value v 2 , and the constant gain value K 2  (adjustment means) regarding the gain profile described with reference to  FIG. 10(A), 11(A) or 12(A)  described above may be provided to the input apparatus  1 . For example, it is only necessary that information on the plurality of different gain profiles be stored in the memory or the like of the input apparatus  1  and the gain profile be switched by a mechanical switch, a static switch, or the like. Alternatively, the mechanical switch, the static switch, and the like may be provided to the control apparatus  40 . 
     Alternatively, the input apparatus  1  or the control apparatus  40  only needs to include software including GUI as the adjustment means. 
     An embodiment is not limited to the above embodiments, and various other embodiments are also possible. 
     A configuration in which the input apparatus  1  includes the acceleration sensor unit  16  but not the angular velocity sensor unit  15  is also conceivable. In this case, the velocity values (V x , V y ) are obtained by integrating the acceleration values (a x , a y ) detected by the acceleration sensor unit  16  in Step  103  (provided that in this case, the angular velocities (ω ψ , ω θ ) about the Y axis and the X axis cannot be obtained). It is also possible to calculate accelerations using an image sensor instead of the acceleration sensor unit  16 . 
     An angle sensor or an angular acceleration sensor may be used instead of the angular velocity sensor unit  15 . As the angle sensor, there are a geomagnetic sensor, an image sensor, and the like. When using the geomagnetic sensor, angle values are detected. Therefore, in this case, the angular velocity values can be obtained by differentiating the angle values. The angular acceleration sensor is constituted of a combination of a plurality of acceleration sensors, and the angular velocity values can be obtained by integrating the angular acceleration values obtained by the angular acceleration sensor. 
     For example, the angular acceleration sensor for detecting angular accelerations about the Y axis and the X axis or a sensor for detecting angles may be used in calculating radius gyrations R(t) as described above. In this case, the angular velocity values (ω ψ , ω θ ) are obtained by integrating the angular acceleration values detected by the angular acceleration sensor. Alternatively, the angular velocity values (ω ψ , ω θ ) are obtained by differentiating the angle values detected by the angle sensor. 
     As a uniaxial angular acceleration sensor as the angular acceleration sensor above, two uniaxial acceleration sensors disposed on the radius gyrations R(t) are typically used. A difference between two acceleration values obtained by the two acceleration sensors is divided by a distance between the two acceleration sensors to thus calculate an angular velocity value of the input apparatus  1 . Similar to the detection principle of the two uniaxial acceleration sensors described above, two biaxial acceleration sensors only need to be used as the biaxial angular acceleration sensor. In this case, in addition to the geomagnetic sensor and the image sensor, the biaxial acceleration sensors only need to be used as the angle sensor so as to realize a principle of obtaining, for example, a roll angle ϕ (angle about Z axis in  FIG. 8 ). Therefore, the two biaxial acceleration sensors only need to be used for detecting biaxial angles about the Y axis and the X axis. 
     The control apparatus  40  may store software for determining a size of the icons  4  displayed on the screen  3  (determination means) in the ROM  37  or other storage devices. The software may be structured so that the user can customize the size of the icons  4 . In this case, the MPU  35  of the control apparatus  40  may adjust at least one of the change rate or tilt of the gain in the range from the threshold value v 1  to the threshold value v 2 , the gain value K 1 , the threshold value v 1 , the threshold value v 2 , and the gain value K 2  in accordance with the determined size of the icons  4  (adjustment means). 
     For example, since accurate pointing may become less necessary as the size of the icons  4  increases, it is only necessary to use a gain profile with which the velocity value of the input apparatus  1  and the like and the pointer velocity value become more linear. In this case, the MPU  35  may store a plurality of gain profiles in advance and extract and use the plurality of gain profiles in accordance with the determined size of the icons  4 . Alternatively, according to the determined size of the icons  4 , the MPU  35  may create a gain profile by an operation and use it. 
     In addition to the gain profiles shown in  FIGS. 10(A), 11(A) , and  12 (A), a configuration in which gain profiles differ (have different hysteresis) between a time of acceleration and a time of deceleration of the input apparatus  1  is also conceivable. 
     In the input apparatus of the above embodiments, input information has been transmitted to the control apparatus wirelessly. However, the input information may be transmitted by wire. 
     The embodiments may be applied to, for example, a handheld-type information processing apparatus (handheld apparatus) including a display section. In this case, by the user moving a main body of the handheld apparatus, a pointer displayed on the display section is moved. Examples of the handheld apparatus include a PDA (Personal Digital Assistance), a cellular phone, a portable music player, and a digital camera. 
     In the above embodiments, the pointer  2  that moves on the screen in accordance with the movement of the input apparatus  1  has been represented as an image of an arrow. However, the image of the pointer  2  is not limited to the arrow and may be a simple circle, square, or the like, or a character image or any other images. 
     The detection axes of each of the angular velocity sensor unit  15  and the acceleration sensor unit  16  of the sensor unit  17  do not necessarily need to be mutually orthogonal like the X′ axis and the Y′ axis described above. In this case, the accelerations respectively projected in the mutually-orthogonal axial directions can be obtained by a calculation that uses a trigonometric function. Similarly, the angular velocities about the mutually-orthogonal axes can be obtained by a calculation that uses the trigonometric function. 
     Descriptions have been given on the case where the X′ and Y′ detection axes of the angular velocity sensor unit  15  and the X′ and Y′ detection axes of the acceleration sensor unit  16  of the sensor unit  17  described in the above embodiments match. However, those detection axes do not necessarily need to match. For example, in a case where the angular velocity sensor unit  15  and the acceleration sensor unit  16  are mounted on a substrate, the angular velocity sensor unit  15  and the acceleration sensor unit  16  may be mounted while being deviated a predetermined rotation angle within a main surface of the substrate so that the detection axes of the angular velocity sensor unit  15  and the acceleration sensor unit  16  do not match. In this case, the accelerations and angular velocities with respect to the respective axes can be obtained by a calculation that uses the trigonometric function. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.