Abstract:
An information processing apparatus including an interface that receives a wireless signal, a power supply that converts an input direct current (DC) power supply into a predetermined voltage by switching the input DC power supply at a switching frequency to generate a driving power supply, and a controller that controls the switching frequency based on a condition of the interface.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of the earlier filing date of U.S. Provisional Patent Application Ser. No. 61/525,471 filed on Aug. 19, 2011, the entire contents of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field of the Disclosure 
     The present disclosure relates to a terminal device such as a mobile phone terminal device, to a terminal control method of controlling the terminal device, and to a program that executes the terminal control method. In particular, the present disclosure relates to a technology that is applied to a terminal device having a function of receiving a radio signal, such as a television broadcast signal. 
     2. Description of Related Art 
     As display panels provided in portable small terminal devices, such as mobile phone terminal devices, display panels having a touch panel have become popular. Touch panels are input devices through which input is possible by touching the display surface thereof with fingers or a pen, and thus, various input operations become possible in coordination with display on a display panel. 
     Additionally, small terminal devices, such as mobile phone terminal devices, are formed into multi-functional terminal devices by incorporating a function differing from the original function, such as a wireless phone call function. For example, mobile phone terminal devices having a function of receiving a television broadcast signal and performing display and audio output of a video by using the received broadcast signal have been developed. 
     SUMMARY 
     In the case where a small terminal device is to receive a television broadcast signal, it is necessary to receive a broadcast signal by using an antenna incorporated or connected in the terminal device, and it is necessary to efficiently receive the broadcast signal by using a comparatively small antenna. A television broadcast signal transmitted from a terrestrial transmitting station is transmitted at, for example, approximately several tens of MHz to several hundreds of MHz, and an antenna provided in the terminal device receives a radio signal at a frequency of several tens of MHz to several hundreds of MHz. 
     Here, in the case where a terminal device that receives a television broadcast signal has a touch panel incorporated therein, harmonics of the signal that is used to drive the touch panel are generated up to approximately several hundreds of MHz, and become interference waves in the case where a television broadcast signal is being received. The reason for this is that since the touch panel is driven with a signal of a comparatively high frequency, harmonics of approximately several hundreds of MHz are generated. 
     Furthermore, the touch panel has a configuration that is integral with a display panel, and it is difficult to prevent interference waves by using a shielding mechanism or the like. Consequently, interference waves are received by an antenna for transmitting/receiving a television broadcast, which is provided in the terminal device. Therefore, in the terminal device including a touch panel, a problem arises in that the reception performance of a television broadcast is deteriorated. 
     It is also considered that while a television broadcast is being received, the operation of the touch panel is stopped, thereby eliminating generation of interference waves by the touch panel and preventing the deterioration of the reception performance of the television broadcast. However, if touch panel operation is stopped, of course, operation of the touch panel cannot be performed while a television broadcast is being received. For example, it is not possible to perform a channel switching operation while a television broadcast is being viewed by using the touch panel. That is, it becomes not possible to perform a simple operation using a touch panel. 
     Here, as the influence of a touch panel operation, the influence on reception of a television broadcast has been described. Interference waves generated at the time of a touch panel operation exert an influence on a signal processing unit, other than a broadcast reception processing unit, inside the terminal device. 
     The present disclosure has been made in view of such points. An object of the present disclosure is to provide a terminal device, a terminal control method, and a program that are capable of reducing the influence of interference waves generated by a touch panel. 
     According to a first embodiment, the disclosure is directed to an information processing apparatus including an interface that receives a wireless signal, a power supply that converts an input direct current (DC) power supply into a predetermined voltage by switching the input DC power supply at a switching frequency to generate a driving power supply, and a controller that controls the switching frequency based on a condition of the interface. 
     According to another embodiment, the disclosure is directed to a power supply method performed by an information processing apparatus. The method includes converting, at a power supply of the information processing apparatus, an input direct current (DC) power supply into a predetermined voltage by switching the input DC power supply at a switching frequency to generate a driving power supply, and controlling, by a controller of the information processing apparatus, the switching frequency based on a condition of a interface of the information processing apparatus that receives a wireless signal. 
     According to another embodiment, the disclosure is directed to a non-transitory computer-readable medium including computer program instructions, which when executed by an information processing apparatus, cause the information processing apparatus to perform a method. The method includes converting an input direct current (DC) power supply into a predetermined voltage by switching the input DC power supply at a switching frequency to generate a driving power supply, and controlling the switching frequency based on a condition of a interface of the information processing apparatus that receives a wireless signal. 
     According to the present disclosure, when a television broadcast is to be received, it is possible to reduce harmonic components contained in the power supply that drives the touch-panel unit, thereby effectively reducing noise from the touch-panel unit to the tuner, and improving the reception situation of the television broadcast. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a block diagram illustrating an example of the configuration of a terminal device according to a first embodiment of the present disclosure. 
         FIG. 2  is a perspective view illustrating an example of the shape of the terminal device of the present disclosure. 
         FIG. 3  is a circuit diagram illustrating an example of the configuration of a power supply circuit of the terminal device according to the first embodiment of the present disclosure. 
         FIG. 4  is an illustration illustrating an example of the operation of the power supply circuit in the example of  FIG. 3 . 
         FIG. 5  is a flowchart illustrating an example of touch-panel control of the terminal device according to the first embodiment of the present disclosure. 
         FIG. 6  is a frequency characteristic view illustrating an example of a receiving state according to the first embodiment of the present disclosure. 
         FIG. 7  is a flowchart illustrating an example of the touch-panel control of a terminal device according to a second embodiment of the present disclosure. 
         FIG. 8  is a frequency characteristic view illustrating an example of a receiving state according to the second embodiment of the present disclosure. 
         FIG. 9  is a flowchart illustrating an example of the touch-panel control of a terminal device according to a third embodiment of the present disclosure. 
         FIG. 10  is a frequency characteristic view illustrating an example of a receiving state according to the third embodiment of the present disclosure. 
         FIG. 11  is a flowchart illustrating a modification of touch-panel control of the terminal device according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Examples of embodiments of the present disclosure will be described in the following order.
     1. First Embodiment   1-1. Configuration of Terminal Device ( FIG. 1 ,  FIG. 2 )   1-2. Configuration of Touch-Panel Power-Supply Unit ( FIG. 3 ,  FIG. 4 )   1-3. Control Operation at Television Broadcast Receiving Time ( FIG. 5 ,  FIG. 6 )   2. Second Embodiment   2-1. Control Operation at Television Broadcast Receiving Time ( FIG. 7 ,  FIG. 8 )   3. Third Embodiment   3-1. Control Operation at Television Broadcast Receiving Time ( FIG. 9 ,  FIG. 10 )   4. Modification ( FIG. 11 )
 
1-1. Configuration of Terminal Device
   

       FIG. 1  illustrates the configuration of a terminal device according to a first embodiment of the present disclosure.  FIG. 2  illustrates an example of the exterior of the terminal device. A terminal device  100  shown in  FIG. 2  is an example in which the terminal device  100  is applied to a multi-functional mobile phone terminal device called a smartphone. As shown in  FIG. 2 , on the surface of the terminal device  100 , a comparatively large (for example, the diagonal line is approximately 4 inches) display panel  121 , and a touch panel  131  that detects the touch of the display surface of the display panel  121  are arranged. The display panel  121  and the touch panel  131  may be configured to be integrated with each other. 
     Furthermore, in the terminal device  100 , a speaker  114  for a phone call is arranged in the upper end of the surface thereof, and a microphone  115  for a phone call and a plurality of operation keys  118  are arranged in the low end of the surface thereof. The operation keys  118  may be arranged at a position (not shown), for example, on the side surface. 
     Next, a description will be given, with reference to  FIG. 1 , of the configuration of the terminal device  100 . The terminal device  100  includes a wireless communication unit  111  for performing wireless communication with a base station for wireless telephone, and an antenna  112  is connected to the wireless communication unit  111 . The wireless communication unit  111  performs radio signal transmission and receiving processing under the control of a central control unit (hereinafter referred to as a “control unit”)  116  through a bus line  101 . 
     When the wireless communication unit  111  receives audio data for a phone call at the time of a voice phone call, the audio data is supplied to the audio processing unit  113  through the bus line  101 , and the audio processing unit  113  performs a demodulation process so as to obtain an analog audio signal. The analog audio signal obtained by the audio processing unit  113  is supplied to the speaker  114 , and audio is output from the speaker  114 . Furthermore, the audio signal output by the microphone  115  is converted into audio data of the transmission format by the audio processing unit  113 , and the converted audio data is supplied to the wireless communication unit  111  through the bus line  101 , whereby the data is transmitted in a wireless manner. The speaker  114  and the microphone  115 , in addition to being incorporated in the terminal device  100 , may be externally provided in the terminal device  100 . For example, a speaker and a microphone of a head set, which are connected to the terminals of the terminal device  100 , may be used. Furthermore, there is a case in which a speaker and a microphone of a head set, which are wirelessly connected to the terminal device, are used. 
     In a case where transmission and reception of data for mail, and data communication that goes through a network, such as the Internet, are to be performed by the wireless communication unit  111 , the wireless communication unit  111  performs transmission and reception processing under the control of the control unit  116 . For example, the data received by the wireless communication unit  111  is stored in a memory  117 , and processing, such as display, based on the stored data, is performed under the control of the control unit  116 . Furthermore, the data stored by the memory  117  is supplied to the wireless communication unit  111 , whereby the data is transmitted in a wireless manner. In the memory  117 , a program necessary to control the terminal device  100  is also stored. For example, a program (to be described later) for executing a process for controlling a power-supply unit  136  of a touch-panel unit  130  is also stored in the memory  117 . 
     Furthermore, an operation instruction from the operation keys  118  and an operation instruction from the touch-panel unit  130  reach the control unit  116  through the bus line  101 , and the control unit  116 , in response to the operation instruction, performs instructions and processing of various operations. 
     The display unit  120  includes a display panel  121 , and a display driving unit  122  for driving the display on the display panel  121 . For the display panel  121 , for example, a liquid-crystal display panel or an organic EL (Electro Luminescence) display panel is used. The display process on the display unit  120  is performed under the control of the control unit  116 . For example, display of a phone call state as the wireless telephone terminal, a telephone directory, and the like, display of electronic mail, display of images obtained from a server that has been accessed through the Internet, and the like are performed under the control of the control unit  116 . Furthermore, the terminal device  100  has a function of receiving and displaying a television broadcast as will be described later, and the received video of the television broadcast is also displayed on the display unit  120 . 
     On the surface of the display panel  121  of the display unit  120 , a touch panel  131  forming the touch-panel unit  130  is arranged. The touch-panel unit  130  performs a touch detection process for detecting that the surface of the touch panel  131  has been touched with fingers or a pen. For the touch-panel unit  130 , for example, touch panels using various methods, such as an electrostatic capacitance method and a resistance film method, can be applied. For example, in the touch-panel unit  130  of the electrostatic capacitance method, many electrodes formed of a transparent conductive film are arranged in the horizontal direction and are also arranged in the vertical direction on the touch panel  131  arranged on the surface of the display panel  121 , so that a change in the electrostatic capacitance of the electrode at the position that a finger has touched (approached) is detected. 
     In order to detect a change in the electrostatic capacitance in the touch panel  131 , the touch-panel control unit  133  performs driving of each electrode through a driving unit  134 . Then, the touch-panel control unit  133  judges the change of the electrostatic capacitance in the detection unit  135  so as to detect which place on the touch panel  131  has been touched. This detection data is sent from the input/output unit  132  to the bus line  101 , and is supplied to the control unit  116 . 
     The terminal device  100  includes a power-supply unit  152  that extracts a DC low-voltage power supply from a battery  151  incorporated in the terminal device  100 , and operates each unit inside the terminal device  100  by using the power supply from the power-supply unit  152 . Furthermore, the touch-panel unit  130  includes a power-supply unit  136  for a touch panel, and performs a process for stepping up the voltage of the DC power supply supplied from the power-supply unit  152 , and generating a power supply for driving the touch panel. By using the power supply of a comparatively high voltage obtained by the power-supply unit  136  for the touch panel, the driving of the electrodes is performed by the driving unit  134 . 
     For the touch-panel power-supply unit  136 , a switching regulator that repeats switching at a set switching frequency is used. The switching frequency can be set at plural steps. The setting of the switching frequency is performed by the touch-panel control unit  133  on the basis of the instructions from the control unit  116 . The configuration of the power-supply unit  136  using the switching regulator and the control operation of the switching frequency will be described later. 
     Furthermore, the terminal device  100  includes a tuner unit  140  that receives a television broadcast. The tuner unit  140  includes an RF front-end unit  141  to which an antenna  146  is connected, and receives an indicated channel among television broadcasts of terrestrial digital broadcasts that are transmitted, for example, from a 400 MHz band to a 700 MHz band. The antenna  146  may be any of an antenna incorporated in the terminal device  100  and an external antenna that is connected through a cable. 
     The signal of the channel, which is received by the RF front-end unit  141  inside the tuner unit  140 , is supplied to a demodulation/correction unit  142 , whereby demodulation/correction is performed thereon by the demodulation/correction unit  142 . The demodulation/correction unit  142  performs, for example, a demodulation process for extracting transmission data that is modulated in each carrier from the signal transmitted as a multi-carrier signal. In addition, the demodulation/correction unit  142  performs a process for correcting the received broadcast data by using correction code attached to the data extracted in the demodulation process. 
     Then, the broadcast data obtained by performing demodulation/correction by the demodulation/correction unit  142  is supplied to the video/audio processing unit  143 . The video/audio processing unit  143  performs a process for extracting video data and extracting audio data, which are contained in the broadcast data. For example, video data and audio data that are coded and transmitted by an MPEG (Moving Picture Experts Group) 2 method, which are contained in the broadcast data, are extracted, and by performing decoding from the MPEG2 coding, video data and audio data are obtained. 
     Then, the video data obtained by the video/audio processing unit  143  is supplied to the display unit  120  from an input/output unit  144  through the bus line  101 , and the video is displayed on the display panel  121 . Furthermore, the audio data obtained by the video/audio processing unit  143  is supplied to the audio processing unit  113  from the input/output unit  144  through the bus line  101 , and audio is output from the speaker  114 . 
     The setting of the receiving channel in the RF front-end unit  141  of the tuner unit  140  is determined and controlled by the tuner control unit  145 . The processing in the demodulation/correction unit  142  and the video/audio processing unit  143  is also performed under the control of the tuner control unit  145 . Furthermore, the demodulation/correction unit  142  obtains values regarding reception sensitivity and reception quality of the received broadcast signal and supplies the values to the tuner control unit  145 . Examples of values regarding reception sensitivity and reception quality include an MER value (Modulation Error Ratio) and a BER value (Bit Error Rate). The MER value is such that a difference between the amplitude and the phase of the received signal and the specified amplitude and phase is converted into a numerical value. The BER value is such that an error rate of the received signal is converted into a numerical value. 
     The tuner control unit  145  receives a television broadcast signal in response to the instructions from the control unit  116  of the terminal device  100 . Furthermore, the tuner control unit  145  supplies data on reception quality, such as an MER value, which are obtained during reception, to the control unit  116 . When the control unit  116  issues an instruction of setting a receiving channel in the tuner control unit  145 , the control unit  116  issues, in driving association with the reception, an instruction of changing the switching frequency of the power-supply unit  136  for the touch panel to the touch-panel control unit  133 . The details of the switching frequency changing process of the power-supply unit  136 , which is drivingly associated with the receiving channel setting of the television broadcast, will be described later. 
     1-2. Configuration of Touch-Panel Power-Supply Unit 
     Next, a description will be given, with reference to  FIGS. 3 and 4 , of the configuration of the power-supply unit  136  for the touch panel. 
       FIG. 3  illustrates the configuration of the power-supply unit  136  for the touch panel. The power-supply unit  136  for the touch panel is a circuit that steps up a power-supply voltage V DD  supplied from the power-supply unit  152  and generates a power-supply voltage V EE  for driving the touch panel. The power-supply voltage V DD  is, for example, a DC voltage of approximately 3 V, and the power-supply voltage V EE  for driving the touch panel is, for example, a DC voltage higher than the power-supply voltage V DD , such as, for example, 6V. 
     A description will be given of the configuration of the power-supply unit  136  shown in  FIG. 3 . An input terminal  11  at which the power-supply voltage V DD  is obtained from the power-supply unit  152  is connected to one end of a capacitor C 1  through a switch S 1 , and the other end of the capacitor C 1  is connected to an output terminal  13  (the other end of the capacitor C 2 ) through a switch S 4  (first state, see  FIG. 4A ). After that, the input terminal  11  is connected to the other end of the capacitor C 1  through a switch S 2 , and one end of the capacitor C 1  is connected to an output terminal  12  (one end of the capacitor C 2 ) through a switch S 3  (second state, see  FIG. 4B ). By performing on/off control of the first state and the second state at high speed, as will be described later, the power-supply voltage V EE  for driving the touch panel is obtained at the output terminals  12  and  13 . 
     The on/off control of each of the switches S 1  to S 4  is performed by the power-supply control unit  14 . A clock CLK is supplied to the power-supply control unit  14  from a clock generation circuit (not shown) inside the terminal device  100  through a clock input terminal  15 . The clock CLK is set as, for example, a clock of a frequency of 24 MHz. The supplied clock CLK is frequency-divided by a frequency-division unit  14   a  inside the power-supply control unit  14 , and a signal of a switching frequency at which the switches Si to S 4  are switched is generated. 
     In this case, the frequency division ratio at which frequency division is performed by the frequency-division unit  14   a  is set using control data Da that is supplied through a control data input terminal  16 , and the switching frequency is varied at plural steps. The control data Da that is obtained in the control data input terminal  16  is supplied from the control unit  116  through the bus line  101 . 
       FIGS. 4A-4B  illustrate the states of the switches Si to S 4  when the power-supply unit  136  operates. 
     At a certain time, as shown in  FIG. 4A , the switch Si and the switch S 4  are turned on, and the switch S 2  and the switch S 3  are turned off. In the state shown in  FIG. 4A , electric charge is stored in the capacitor C 1  at the power-supply voltage V DD  obtained in the input terminal  11 . 
     After that, as shown in  FIG. 4B , the switch Si and the switch S 4  are turned off, and the switch S 2  and the switch S 3  are turned on. In the state shown in  FIG. 4B , the power-supply voltage V DD  obtained in the input terminal  11  is applied to the other end side (in the lower side in the figure) of the capacitor C 1 , and the electrical potential of one end side (+side) of the capacitor C 1  becomes ( 2  V DD ). 
     In the state shown in  FIG. 4B , since the switch S 3  is in an on state, electric charge is stored in the capacitor C 2  at a voltage twice the power-supply voltage V DD . Then, as a result of returning from the state of the switch shown in  FIG. 4B  to the state of the switch shown in  FIG. 4A , the voltage of ( 2  V DD ) stored in the capacitor C 2  is obtained as a power-supply voltage V EE  in the output terminals  12  and  13 . However, the time period during which the voltage V EE  twice the input voltage is output from the capacitor C 2  is a short time period corresponding to the capacitances of the capacitors C 1  and C 2 . In order to maintain the output voltage V EE  at a stabilized fixed voltage value, it is necessary to alternately switch between the switch state shown in  FIG. 4A  and the switch state shown in  FIG. 4B . In the example of the present embodiment, at the time of the normal state, by setting, to 24 MHz, the switching frequency at which a switch is switched, the state shown in  FIG. 4A  and the state shown in  FIG. 4B  are repeated. When the switching frequency is 24 MHz, the power-supply voltage V EE  obtained in the output terminals  12  and  13  becomes a stabilized voltage value with small variations, and a satisfactory power supply for driving the touch panel is obtained. 
     Furthermore, in the example of the present embodiment, by switching the frequency division ratio of the frequency-division unit  14   a  inside the power-supply control unit  14  shown in  FIG. 3 , the switching frequency can be set to 12 MHz and 6 MHz in addition to 24 MHz at a normal time. The switching of the switching frequency is performed using the control data Da that is supplied from the control unit  116  through the control data input terminal  16 . In the case where the switching frequency is set to 12 MHz or 6 MHz, the stability of the power-supply voltage V EE  becomes worse, and a ripple voltage at which the voltage varies is generated at the switching frequency. The lower the switching frequency becomes, the larger the ripple voltage becomes. 
     The power-supply voltage V EE  that is generated in the power-supply unit  136  shown in  FIGS. 3 and 4  is a voltage for driving the touch-panel unit  130 . From the viewpoint of the stabilized operation of the touch-panel unit  130 , it is preferable that, originally, the power-supply voltage V EE  is a power supply with a small ripple voltage. Therefore, in a situation (at normal operation time) in which the switching frequency does not need to be limited, the switching frequency is set to 24 MHz. 
     However, even with the power-supply voltage V EE  in which a ripple voltage is generated at a comparatively high voltage with the switching frequency being set to 12 MHz or 6 MHz, it is possible to drive the touch-panel unit  130 . For this reason, in the case of a situation in which a high switching frequency like 24 MHz is undesirable for the terminal device  100 , the switching frequency is set to 12 MHz or 6 MHz under the control of the control unit  116 . A process for switching the switching frequency will be described with reference to the flowchart of  FIG. 5  below. In the case where the switching frequency in the power-supply unit  136  is low, response of detecting the touch of the panel surface by the touch-panel unit  130  becomes slightly slow due to the influence of the ripple voltage. 
     1-3. Control Operation at Television Broadcast Receiving Time 
     Next, with reference to the flowchart of  FIG. 5  and the frequency characteristic view of  FIG. 6 , a description will be given of processing in a case where a television broadcast is received by the terminal device  100 . 
     The tuner unit  140  inside the terminal device  100  receives a terrestrial digital broadcast S ISDB  of the band of several hundreds of MHz. In the case where a terrestrial digital broadcast S ISDB  is received, harmonics at a step-up switching frequency in the power-supply unit  136  provided in the touch-panel unit  130  become interference waves S NOISE  overlapping the reception frequency, and may cause interference to the reception of the television broadcast. If there are interference waves S NOISE  overlapping the reception frequency, the reception of the television broadcast in the tuner unit  140  is obstructed, the receiving state becomes poor, and in the worst case, a state in which a television broadcast cannot be received is assumed. In particular, in the case where a comparatively large display panel  121  and touch panel  131  are arranged in the small terminal device  100  shown in  FIG. 2 , such a problem appears noticeably. That is, inside the terminal device  100 , it is difficult to greatly separate the arrangement positions of the touch panel  131  on which detection electrodes are arranged and an antenna  146  for broadcast reception, and there is a high probability that harmonics of the power supply that drives the touch panel cause interference to the broadcast signal received by the antenna. 
     In the present embodiment, in order to prevent such generation of harmonics that cause interference to the reception in the tuner unit  140 , the control unit  116  performs control of the switching frequency corresponding to the operating state of the tuner unit  140 . 
     The flowchart of  FIG. 5  illustrates an example of a control process of the control unit  116  for the purpose of preventing generation of harmonics. 
     Initially, the control unit  116  determines whether or not there is a user operation for receiving a television broadcast (step S 11 ). The user operation is, for example, an operation based on touch detection in the touch-panel unit  130 , or an operation using the operation keys  118 . In this determination, when it is determined that there is no user operation for receiving a television broadcast, the control unit  116  waits until there is a user operation for receiving a television broadcast. 
     Then, when it is determined in step S 11  that there is a user operation for receiving a television broadcast, the control unit  116  instructs the tuner control unit  145  to receive a television broadcast of a channel indicated by the user operation, and the tuner unit  140  starts reception (step S 12 ). Then, following the reception start in the tuner unit  140 , an instruction of lowering the switching frequency of the power-supply unit  136  is sent from the control unit  116  to the touch-panel control unit  133  so as to lower the switching frequency of the power-supply unit  136  for the touch-panel unit  130  (step S 13 ). The lowering of the switching frequency is performed by changing the frequency division ratio of the frequency-division unit  14   a  shown in  FIG. 3 , for example, the switching frequency is changed from 24 MHz at a normal time to 12 MHz. 
     Then, video data that is received and obtained by the tuner unit  140  is supplied to the display unit  120 , whereby the video data is displayed (step S 14 ). After the display of the broadcast video has started, the control unit  116  determines whether or not a user operation for stopping the reception of the television broadcast has been performed (step S 15 ). As long as no operation for stopping the reception of the television broadcast has been performed, the state in which the switching frequency has been lowered is maintained. 
     When it is determined in step S 15  that there is a user operation for stopping the reception of the television broadcast, an instruction of returning the switching frequency of the power-supply unit  136  to the original frequency is sent from the control unit  116  to the touch-panel control unit  133  (step S 16 ). As a result of this instruction, the switching frequency of the power-supply unit  136  for the touch-panel unit  130  becomes the original frequency. 
     Then, in response to the instruction from the control unit  116 , the reception of the television broadcast signal in the tuner unit  140  is stopped, and the display of the received video on the display unit  120  is stopped (step S 17 ). 
     A description will be given, with reference to  FIG. 6 , of the effect obtained by performing the control process of the flowchart of  FIG. 5 . 
       FIGS. 6A and 6B  illustrate an overview of a situation in which interference waves that are emitted by the power-supply unit  136  in a switching operation in the band of the television broadcast signal received by the tuner unit  140  are generated. Channels C 1 , C 2 , and C 3  shown in  FIGS. 6A and 6B  are portions of channels of a terrestrial digital broadcast S ISDB  received by the tuner unit  140 . The channels C 1 , C 2 , and C 3  are channels of a comparatively low frequency band of, for example, approximately 400 MHz. Noise N T  shown in  FIGS. 6A and 6B  is thermal noise. This thermal noise N T  is contained at a fixed level at any frequency. 
       FIG. 6A  illustrates an example in which the switching frequency of the power-supply unit  136  for the touch-panel unit  130  is 24 MHz at a normal time.  FIG. 6B  illustrates an example in which the switching frequency of the power-supply unit  136  for the touch-panel unit  130  is set at 12 MHz. 
     In the case of 24 MHz at a normal time shown in  FIG. 6A , noise N Fa  due to harmonics of the switching frequency of 24 MHz has reached the transmission frequencies of the channels C 1 , C 2 , and C 3 . That is, the received signal of the channel C 1  contains noise N C1 , the received signal of the channel C 2  contains noise N C2 , and the received signal of the channel C 3  contains noise N C3 . Noise N Fa  due to harmonics of the switching frequency decreases with an increase in the frequency of the receiving channel, as shown in  FIG. 6A . 
     In comparison, in a case where the switching frequency of the power-supply unit  136  is set to 12 MHz, as shown in  FIG. 6B , noise N C2  due to harmonics of the switching frequency of 12 MHz does not reach the transmission frequencies of the channels C 1 , C 2 , and C 3 . Therefore, when the transmission frequencies of the channels C 1 , C 2 , and C 3  are received, noise from the power-supply unit  136  is not contained. 
     At the time of the television broadcast reception shown in the flowchart of  FIG. 5 , reception is performed in the state shown in  FIG. 6B . Since a broadcast signal is received by the tuner unit  140  in a state in which there is no influence of power-supply noise, reception becomes possible in a satisfactory situation in which there is no influence of noise. 
     In the case where the switching frequency of the power-supply unit  136  of the touch-panel unit  130  is set to 12 MHz, which is a lower frequency, a comparatively large ripple voltage is contained in the power-supply voltage. For this reason, the detection situation of the touch-panel unit  130  that is driven by the power supply becomes worse than that at a normal time, and the response of detecting the touch of the panel surface becomes slower than in the case in which the touch-panel unit  130  is driven at the normal switching frequency. 
     However, in the situation in which the received video of the television broadcast is being displayed on the display unit  120 , only limited operations are performed regarding a touch panel operation, and there is no need for high-speed touch detection. Specifically, the operations are a touch operation for channel switching, a touch operation for stopping broadcast reception, a touch operation for sound volume up/down, and the like. Most of them are operations that do not demand a high-speed operation, and inconvenience due to the response of the touch detection becoming slow does not occur. 
     Therefore, according to the terminal device  100  in accordance with an example of the present embodiment, while a television broadcast is being received by the terminal device  100 , generation of an interference wave from the power-supply unit  136  for the touch panel is reduced, and satisfactory reception of a television broadcast with no influence from an interference wave can be performed. Moreover, the operation of lowering the switching frequency is performed while a television broadcast is being received. Consequently, the response of the touch detection of the touch panel is fast other than while a television broadcast is being received and displayed, and the ease of use of the terminal device does not become worse. 
     2. Second Embodiment 
     Next, a description will be given, with reference to  FIGS. 7 and 8 , of an example of a second embodiment of the present disclosure. 
     In the example of the present embodiment, for the configuration of the terminal device, the configuration of the terminal device  100 , which is described with reference to  FIGS. 1 and 2  in the example of the first embodiment, is applied. 
     Then, in the example of the present embodiment, the control operation performed by the control unit  116  when a television broadcast is received by the tuner unit  140  of the terminal device  100  and displayed on the display unit  120  differs from the example of the first embodiment. 
     Furthermore, the power-supply unit  136  provided in the touch-panel unit  130  of the terminal device  100  of the example of the present embodiment can set the switching frequency at three steps under the control of the touch-panel control unit  133 . That is, a switching frequency F 1  at a normal time, a switching frequency F 2  that is decreased one step from the normal state, and a switching frequency F 3  that is decreased further one step can be set under the control of the touch-panel control unit  133 . Specifically, the switching frequencies F 1 , F 2 , and F 3  are set at 24 MHz, 12 MHz, and 6 MHz in this example, respectively. 
     2-1. Control Operation at Television Broadcast Receiving Time 
     A description will be given, with reference to the flowchart of  FIG. 7 , of control operation performed by the control unit  116  when a television broadcast is received in the example of the present embodiment. 
     As shown in the flowchart of  FIG. 7 , initially, the control unit  116  determines whether or not there is a user operation for receiving a television broadcast (step S 21 ). In this determination, when it is determined that there is no user operation for receiving a television broadcast, the control unit  116  waits until when there is a user operation for receiving a television broadcast. 
     Then, when it is determined in step S 21  that there is a user operation for receiving a television broadcast, the control unit  116  instructs the tuner control unit  145  to receive a television broadcast of the channel indicated by the user operation, and reception by the tuner unit  140  is started (step S 22 ). Then, the control unit  116  judges which one of the channels C 1  and C 2  of a first group, the channels C 3  and C 4  of a second group, and the channel C 5  (or frequency higher than that of channel C 5 ) of a third group the receiving channel is (step S 23 ). The transmission frequencies of the channels of the groups are such that the channel of the first group is a channel of the lowest frequency, and the frequency relationship: the first group &lt;the second group &lt;the third group holds. 
     When it is determined in step S 23  that the receiving channel is to receive the channel C 1  or C 2  of the first group, an instruction of setting the switching frequency of the power-supply unit  136  to F 3  is sent from the control unit  116  to the touch-panel control unit  133 . The touch-panel control unit  133  receiving this instruction sets the switching frequency of the power-supply unit  136  for the touch-panel unit  130  to a frequency F 3  (6 MHz) (step S 24 ). 
     Furthermore, when it is determined in step S 23  that the receiving channel is to receive the channel C 3  or C 4  of the second group, an instruction of setting the switching frequency of the power-supply unit  136  to F 2  is sent from the control unit  116  to the touch-panel control unit  133 . The touch-panel control unit  133  receiving this instruction sets the switching frequency of the power-supply unit  136  for the touch-panel unit  130  to a frequency F 2  (12 MHz) (step S 25 ). 
     In addition, when it is determined in step S 23  that the receiving channel is to receive the channel C 5  of the third group, the control unit  116  sets the switching frequency of the power-supply unit  136  to F 1  (24 MHz) (step S 26 ). The switching frequency F 1  (24 MHz) is a switching frequency at a normal time. 
     Then, in a state in which the switching frequency is set at each of steps S 24 , S 25 , and S 26  in correspondence with the receiving channel, the video data that is received and obtained by the tuner unit  140  is supplied to the display unit  120  and displayed thereon (step S 27 ). After the display of the broadcast video is started, it is determined whether or not there is an operation of changing the receiving channel of the television broadcast (step S 28 ). When it is determined that there is a changing operation, the process returns to the determination of step S 23 . Then, in the processing of steps S 23  to S 26 , the switching frequency is set as a switching frequency corresponding to the channel group after being changed. 
     When it is determined in step S 28  that there is no changing operation of the receiving channel of the television broadcast, next, it is determined whether or not there is a user operation of stopping the reception of the television broadcast (step S 29 ). In a case where there is no stopping operation, the display of the received video in step S 27  is continued. 
     When it is determined in step S 29  that there is a user operation for stopping the reception of the television broadcast, an instruction of returning the switching frequency of the power-supply unit  136  to the frequency F 1  at a normal time is sent from the control unit  116  to the touch-panel control unit  133  (step S 30 ). In response to this instruction, the switching frequency of the power-supply unit  136  for the touch-panel unit  130  becomes the original frequency F 1 . In a situation in which the frequency F 1  corresponding to the channel C 5  is set in step S 26 , the switching frequency that is set in step S 30  is the same, and thus, an instruction, such as a change of the frequency, is not necessary. 
     Then, in response to the instruction from the control unit  116 , the reception of the television broadcast signal by the tuner unit  140  is stopped, and the display of the received video on the display unit  120  is stopped (step S 31 ). 
     A description will be given, with reference to  FIG. 8 , of the effect obtained by performing the control process of the flowchart of  FIG. 7 . 
       FIGS. 8A-8C  illustrate an overview of a situation in which an interference wave emitted by the power-supply unit  136  in a switching operation in the band of the television broadcast signal that is received by the tuner unit  140  is generated. Channels C 1 , C 2 , C 3 , C 4 , and C 5  shown in  FIGS. 8A-8C  are portions of the channel of the terrestrial digital broadcast S ISDB  that is received by the tuner unit  140 . A broadcast channel does not exist at a frequency lower than that of the channel C 1 . Noise N T  shown in  FIGS. 8A ,  8 B and  8 C is thermal noise. This thermal noise N T  is contained at a fixed level at any frequency.  FIG. 8A  illustrates an example when the switching frequency of the power-supply unit  136  for the touch-panel unit  130  is a frequency F 1  (24 MHz).  FIG. 8B  illustrates an example of the switching frequency F 2  (12 MHz) of the power-supply unit  136  for the touch-panel unit  130 .  FIG. 8C  illustrates an example of the switching frequency F 3  (6 MHz) of the power-supply unit  136  for the touch-panel unit  130 . 
     In the case of 24 MHz at a normal time shown in  FIG. 8A , noise N F1  due to harmonics at the switching frequency of 24 MHz has reached the transmission frequencies of the channels (channel C 1  to channel C 4 ) of the first group and the second group. That is, the received signal of the channel C 1  contains noise N C1 , the received signal of the channel C 2  contains noise N C2 , the received signal of the channel C 3  contains noise N C3 , and the received signal of the channel C 4  contains noise N C4 . Noise N C1  to noise N C4  at each channel due to harmonics of the switching frequency are at a lower level with an increase in the frequency of the channel. 
     In the state of  FIG. 8A , in the channel C 5  (and channel at a frequency higher than that) of the third group, noise N F1  due to harmonics of the switching frequency does not become an interference wave. For this reason, as shown in the flowchart of  FIG. 8 , when the channel C 5  of the third group and a channel at a frequency higher than that are to be received, the channel C 5  can be satisfactorily received while the switching frequency of the power-supply unit  136  is maintained at the frequency F 1  (24 MHz) F 1  at a normal time. 
     In a case where the switching frequency of the power-supply unit  136  is set at 12 MHz, as shown in  FIG. 8B , noise N F2  due to harmonics at the switching frequency of 12 MHz has reached only the transmission frequencies of the channels C 1  and C 2  of the first group. The noise N F2  due to harmonics of the switching frequency of 12 MHz has not reached the channel C 3  and a channel at a frequency higher than that. Therefore, as shown in the flowchart of  FIG. 7 , when the channels C 3  and C 4  of the second group are to be received, by setting the switching frequency of the power-supply unit  136  to the frequency F 2  (12 MHz) lower one step than that at a normal time, it is possible to satisfactorily receive these channels. 
     In a case where the switching frequency of the power-supply unit  136  is set to 6 MHz, as shown in  FIG. 8C , noise N F3  due to harmonics of the switching frequency of 6 MHz is at a frequency lower than that of the channel C 1 . 
     Therefore, as shown in the flowchart of  FIG. 7 , when the channels C 1  and C 2  of the first group are to be received, by setting the switching frequency of the power-supply unit  136  to the frequency F 3  (6 MHz) that is two steps lower than that at a normal time, it is possible to satisfactorily receive these channels. 
     As described above, in the case of the example of the present embodiment, the switching frequency of the power-supply unit  136  for the touch panel is set at plural steps in correspondence with the receiving channel so that an interference wave is not generated, and thus, television broadcasts of individual channels can be satisfactorily received. 
     Moreover, since the switching frequency is set in correspondence with each channel, it is possible to minimize an influence of decrease of the touch detection operation of the touch panel due to a decrease in the switching frequency. As in the channel C 5  shown in  FIG. 8A , regarding a channel at a comparatively high frequency, the switching frequency is maintained at that at a normal time. When the channel is to be received, the touch detection operation of the touch panel can be performed at a speed and accuracy similar to those at a normal time. 
     3. Third Embodiment 
     Next, an example of a third embodiment of the present disclosure will be described with reference to FIGS.  9  and  10 A- 10 C. 
     In the example of the present embodiment, for the configuration of the terminal device, the configuration of the terminal device  100  described with reference to  FIGS. 1 and 2  in the example of the first embodiment is applied. 
     Then, in the example of the present embodiment, the control operation performed by the control unit  116  when the tuner unit  140  of the terminal device  100  receives a television broadcast and the display unit  120  displays the television broadcast differs from the examples of the first and second embodiments. 
     Furthermore, in the example of the present embodiment, the tuner unit  140  obtains a value for the reception sensitivity of the television broadcast signal, and the control unit  116  judges the value regarding this reception sensitivity. For the value regarding reception quality, in this example, an MER value (Modulation Error Ratio) corresponding to a CN ratio is used. The better the reception sensitivity becomes, the higher value the MER value becomes. In place of the MER value, a BER value (Bit Error Rate) may be used. Alternatively, both the MER value and the BER value may be used. 
     3-1. Control Operation At Television Broadcast Receiving Time 
     With reference to the flowchart of  FIG. 9 , a description will be given of control operation performed by the control unit  116  when a television broadcast is to be received in the example of the present embodiment. 
     As shown in the flowchart of  FIG. 9 , first, the control unit  116  determines whether or not there is a user operation for receiving a television broadcast (step S 41 ). In this determination, when it is determined that there is no user operation for receiving a television broadcast, the control unit  116  waits until there is a user operation for receiving a television broadcast. 
     Then, when it is determined in step S 41  that there is a user operation for receiving a television broadcast, the control unit  116  instructs the tuner control unit  145  to receive the television broadcast of the channel indicated by the user operation, and causes reception in the tuner unit  140  to start (step S 42 ). Then, at this time, the control unit  116  judges the MER value obtained by the tuner unit  140  so as to determine whether or not the MER value is a value which is less than a threshold value serving as a reference or a value which is greater than or equal to the threshold value (step S 43 ). The control unit  116  determines whether or not, for example, the MER value is less than  15 . Here, in a case where the MER value is less than  15 , the reception sensitivity is in a comparatively low state. An instruction of lowering the switching frequency of the power-supply unit  136  is sent from the control unit  116  to the touch-panel control unit  133 . The touch-panel control unit  133  receiving this instruction sets the switching frequency of the power-supply unit  136  for the touch-panel unit  130  to a frequency (12 MHz) that is lowered one step from the frequency (24 MHz) at a normal time (step S 44 ). 
     In a case where the MER value is 15 or is greater than or equal to 15 in step S 43 , the switching frequency of the power-supply unit  136  is maintained at the frequency at a normal time (that is, 24 MHz). 
     Then, the touch-panel control unit  133  supplies the video data received and obtained by the tuner unit  140  to the display unit  120 , whereby the video data is displayed (step S 45 ). After the display of the broadcast video is started, it is determined whether or not there is a change in the receiving state at a certain or higher level in the tuner unit  140  (step S 46 ). The change at a certain or higher level at this point refers to, for example, a case in which the reception level of a broadcast signal has greatly changed or a case in which the receiving channel has changed to another channel. In a case where there is such a change, the process returns to the determination of step S 43 . 
     If it is determined in step S 46  that there is no change in the receiving state at a certain or higher level, next, it is determined whether or not there is a user operation for stopping the reception of the television broadcast (step S 47 ). In the case where there is no operation for stopping the reception of the television broadcast, the display of the received video in step S 45  is continued. 
     When it is determined in step S 47  that there is a user operation for stopping the reception of the television broadcast, an instruction of returning the switching frequency of the power-supply unit  136  to the frequency at a normal time is sent from the control unit  116  to the touch-panel control unit  133  (step S 48 ). In response to this instruction, the switching frequency of the power-supply unit  136  for the touch-panel unit  130  becomes the original frequency. When it is determined in step S 43  that the MER value is an MER value of greater than or equal to the threshold value, an instruction, such as a change of the frequency, is not necessary in step S 48 . 
     Then, in response to the instruction from the control unit  116 , the reception of the television broadcast signal in the tuner unit  140  is stopped, and the display of the received video on the display unit  120  is stopped (step S 49 ). 
     The effect obtained by performing the control process of the flowchart of  FIG. 9  will be described with reference to  FIG. 10 .  FIGS. 10A-10C  illustrate an overview of a situation in which an interference wave that is emitted by a switching operation in a specific channel C 0  while the tuner unit  140  is performing reception is generated. Noise N T  shown in  FIGS. 10A ,  10 B, and  10 C is thermal noise. The thermal noise N T  is contained at a fixed level at any frequency. 
       FIG. 10A  illustrates an example in a case in which noise N Fa  of a switching frequency due to harmonics is contained at the frequency of the channel C 0  that is performing reception. In the case of  FIG. 10A , it is assumed that the reception level of the channel CO that is performing reception is sufficiently high, and reception quality CN 1  is set at a CN ratio corresponding to a state in which the MER value is greater than or equal to 15. At this time, even if noise N Fa  due to harmonics of the switching frequency is not reduced, satisfactory reception in the tuner unit  140  is possible, and the switching frequency is not changed. 
       FIG. 10B  illustrates an example of a CN ratio in a case where the reception level of the channel CO that is performing reception is lower than that in the case of  FIG. 10A , the reception sensitivity of the receiving channel C 0  is lower than that, and reception quality CN 2  is set at an MER value of less than 15. In this case, a process for reducing noise N Fa  due to harmonics by changing the switching frequency is performed. 
       FIG. 10C  illustrates a case in which, in the detection of the state shown in  FIG. 10B , the switching frequency is changed to a lower frequency, and noise N Fb  due to harmonics is reduced. As shown in  FIG. 10C , the noise N Fa  is reduced as a result of the change of the switching frequency, no influence is received in the reception of the channel C 0 , and the MER value is increased. Therefore, it becomes possible for the tuner unit  140  to perform satisfactory reception. In step S 43  of the flowchart of  FIG. 9 , by using only the determination as to whether or not the MER value is less than a fixed threshold value in step S 43 , the switching frequency of the power-supply unit  136  of the touch-panel unit  130  is controlled. The switching frequency may be controlled on the basis of finer determination. 
     For example, when the MER value that is received and obtained by the tuner unit  140  becomes 12, which is slightly higher than 7, which is the value of a sensitivity point, the switching frequency of the power-supply unit  136  is decreased to a frequency lower than that at a normal time. Then, when the MER value becomes greater than or equal to 5, a process for returning the switching frequency of the power-supply unit  136  to that at a normal time is performed. 
     In the manner described above, by controlling the switching frequency of the power-supply unit  136 , the influence of the power-supply noise in the tuner unit  140  is limited to the receiving state in the vicinity of the sensitivity point, and reception can be stably performed without being affected by power-supply noise. 
     Furthermore, in the example of FIGS.  9  and  10 A- 10 C, an example has been described in which the switching frequency of the power-supply unit is switched at two steps. Alternatively, the switching frequency may be switched at three steps or more finely than that. For example, as described in the example of the second embodiment, the switching frequency is set at three steps. In a case where the MER value is low, control may be performed such that the switching frequency is gradually lowered until a fixed or higher MER value at which satisfactory reception is possible is obtained. 
     4. Modification 
     In the examples of the embodiments up to this point, a description has been given of processing in which an interference wave from a touch panel is reduced in a case where the terminal device  100  receives a television broadcast signal. The interference wave from the touch panel can exert an adverse influence on the signal processing unit inside the terminal device  100 . Therefore, the switching frequency of the touch-panel power supply may be switched in accordance with the operating situation of the signal processing unit inside the terminal device  100 . 
       FIG. 11  is a flowchart illustrating an example of a process for switching the switching frequency of the touch-panel power supply in correspondence with a wireless communication channel (frequency) when the wireless communication unit  111  of the terminal device  100  performs a wireless communication process with a wireless base station. 
     As shown in  FIG. 11 , first, the control unit  116  determines whether or not there is a user operation for starting a phone call by wireless communication with the wireless base station. In this determination, when it is determined that the there is no user operation for starting a phone call, the control unit  116  waits until there is a user operation for starting a phone call. 
     Then, when it is determined in step S 51  that there is a user operation for starting a phone call, the control unit  116  determines whether or not the communication channel (frequency) that is used in wireless transmission of phone call audio at this time is a frequency that causes interference in the touch-panel power supply (step S 52 ). The phone call channel is a channel that is assigned from the wireless base station subject to availability of the wireless communication channel. To which degree the frequency used in each communication channel causes interference at the switching frequency of the touch-panel power supply can be determined by performing measurements in advance. 
     Alternatively, in a case where a plurality of frequency bands, that is, a several hundreds of MHz band, and a several GHz band, are provided as frequency bands used for wireless communication, the entire channel of the several hundreds of MHz band, which is a lower frequency band, may be set as a channel in which there is interference. 
     When it is determined in step S 52  that the communication channel is at a frequency at which interference is not received from the touch-panel power supply, an instruction of setting the switching frequency of the power-supply unit  136  to F 2  is sent from the control unit  116  to the touch-panel control unit  133 . The touch-panel control unit  133  receiving this instruction sets the switching frequency of the power-supply unit  136  for the touch-panel unit  130  to a frequency F 2  (12 MHz) (step S 53 ). 
     Furthermore, when it is determined in step S 52  that the communication channel is at a frequency at which no interference is received from the touch-panel power supply, the control unit  116  sets the switching frequency of the power-supply unit  136  to F 1  (24 MHz) (step S 54 ). The switching frequency F 1  (24 MHz) is a switching frequency at a normal time. 
     Then, the control unit  116  causes a voice phone call to be started in a state in which the switching frequency is set in each of steps S 53  and S 54  in correspondence with a phone call channel (step S 55 ). After this voice phone call is started, it is determined whether or not there is an instruction of changing the communication channel (step S 56 ). The change of the communication channel is performed one after another at the time of a change in the wireless communication environment even during the phone call. Furthermore, the change of the communication channel occurs when the wireless base station of another party with which wireless communication is performed is switched. 
     When there is a channel change in this determination, the process returns to the determination of step S 52 . Then, in the processing of steps S 52  to S 54 , the switching frequency is set as a switching frequency corresponding to the communication channel after being changed. 
     When it is determined in step S 56  that there is no change of the communication channel, next, it is determined whether or not there is a user operation for ending the phone call (step S 57 ). When there is no operation for stopping the phone call, the phone call process in step S 55  is continued. 
     When it is determined in step S 57  that there is a user operation for ending the phone call, an instruction of returning the switching frequency of the power-supply unit  136  to the frequency F 1  at a normal time is sent from the control unit  116  to the touch-panel control unit  133  (step S 58 ). Under this instruction, the switching frequency of the power-supply unit  136  for the touch-panel unit  130  becomes the original frequency F 1 . In a situation where the frequency F 1  has been set in step S 54 , the switching frequency that is set in step S 30  is the same, and an instruction, such as a change of frequency, is not necessary. 
     Then, in response to the instruction from the control unit  116 , the wireless communication for a voice phone call is stopped (step S 59 ). 
     In a case where, as described above, while the voice phone call is being performed, the wireless communication channel (frequency) that performs wireless communication with the wireless base station is interfered by harmonics of the switching frequency of the touch-panel power supply, the switching frequency is changed to a lower frequency. Therefore, choices of the optimal wireless communication channel increase, and the communication state is improved. 
     In particular, in a weak electric-field state in which wireless communication is performed in a situation comparatively far from the wireless base station, better wireless communication becomes possible. 
     In the processing of the flowchart of  FIG. 11 , the switching frequency is changed in accordance with the wireless communication channel during a phone call. However, during the phone call, the switching frequency may be always set to be low. Alternatively, similarly to the processing described in the flowchart of  FIG. 7 , the switching frequency may be changed at three steps or at steps more than that in accordance with the interference situation in the wireless communication channel. 
     Furthermore, here, wireless communication time for a voice phone call is assumed. Alternatively, similar control may be performed also when another wireless communication is performed between the terminal device and the wireless base station. Furthermore, the control of the switching frequency in accordance with these wireless communication channels can be performed in combination with the control at the time of the reception of a television broadcast signal by the above-mentioned tuner. That is, it is sufficient that the control unit  116  performs processing described in the example of each embodiment when a television broadcast is received, and performs processing described in the flowchart of  FIG. 11  at the time of wireless communication, such as during a phone call. Alternatively, the control unit  116  may singly perform only the processing at the time of wireless communication shown in the flowchart of  FIG. 11 . 
     The terminal device  100  described in the example of the first embodiment is configured as a mobile phone terminal. In addition, the terminal device  100  may be applied to a terminal device of another configuration. That is, the terminal device  100  can be applied to various terminal devices having a function of receiving a television broadcast signal, and a touch panel. For example, the terminal device  100  may be applied to a car navigation device including a touch panel and to a terminal device having a television broadcast receiving function incorporated therein. 
     Furthermore, in the example of each embodiment, the touch-panel unit is configured to include a step-up power-supply unit and control a switching frequency in a power-supply unit inside the touch-panel unit. In contrast, the power-supply unit (the power-supply unit  152  in  FIG. 1 ) that is connected to a battery inside the terminal device may be configured to include a circuit that performs a similar stepping-up operation, and the power-supply unit may be configured to directly supply the stepped-up power supply to the touch-panel unit, so that the frequency in the power-supply unit is controlled. 
     Furthermore, the configuration of the power-supply unit that performs stepping up, which is shown in  FIG. 3 , shows only an example, and another configuration may also be employed. The values of 24 MHz and 12 MHz shown as the switching frequencies of the power-supply unit show only examples, and another switching frequency may be used. The transmission bands of the television broadcast signal to be received show only examples, and may be applied to a case in which a broadcast signal of another band is to be received. 
     Furthermore, the control unit (central control unit) that controls the operation of the entire terminal device is configured to perform a process for controlling the switching frequency of the power-supply unit. Alternatively, the tuner control unit or the touch-panel control unit may issue an instruction of controlling the switching frequency. 
     Furthermore, in the example of each embodiment, after the switching frequency of the power-supply unit is lowered when the reception of the television broadcast is started, the switching frequency is maintained until the reception of the television broadcast is stopped. In comparison, for example, even in a state in which the reception of the television broadcast in the tuner is continued, when a touch is detected in the touch-panel unit, the switching frequency may be temporarily returned to the original frequency, and touch detection accuracy may be temporarily returned to the original. In this case, for example, after the switching frequency is returned to the original frequency, when touch detection does not occur for a certain time period, the switching frequency may be returned to the lowered switching frequency once more. 
     Furthermore, in the examples of the embodiments, the terminal device  100  in which a control program executed by the control unit  116  is incorporated in advance so that an operation of controlling the switching frequency of the touch-panel unit is performed has been used. In comparison, by implementing a program (software) including steps for performing a control processing method of the present disclosure in the existing terminal device including a touch panel and a television broadcast reception tuner, a terminal device that performs corresponding operations may be obtained. For the terminal device implementing programs, various information processing terminals, such as a computer device into which a program can be installed, can be applied.