Abstract: The present inventions relates to electrophoretic displays that are switchable between a grayscale updating mode (502) and a monochrome updating mode (501). The monochrome updating mode (501) provides for extreme pixel states only (e.g. black and white), whereas the grayscale updating mode (501) provides for intermediate grayscale pixels states as well. According to the present invention, a suitably selected transition signal (504) is applied when switching from the grayscale updating mode (502) to the monochrome updating mode (501). The transition signal (504) involves a drive pulse that serves to reduce the level of remnant DC voltage otherwise occurring in each pixel due to differences in the grayscale updating mode (502) and the monochrome updating mode (501).

Abstract: A portable display device includes a flexible electrophoretic display, a circuit board electrically connected to the display, and a base receiving and securing the display and the circuit board therein. The display includes a pair of electrodes for providing an electric field therebetween, and a microcapsule layer positioned between the electrodes. The circuit board is electrically connected to the electrodes of the display for providing power to the electrodes and controlling the electric field generated between the electrodes. The base comprises at least two portion foldable to each other to thereby allow the display to be foldable with the at least two portions.

Abstract: An addressable brush contact array comprising oriented conductive fibers attached to addressing electrodes to transfer imagewise charge to or from an array of individual electrodes on a two dimensional surface. The two dimensional surface receiving this charge can be, for example, the writing surface of an electronic paper display or the drum of a xerographic printer. The addressing electrodes generally consist of one or more linear rows of electrodes on a narrow wand or addressing bar. More than one row of electrodes the electrodes of each row may be staggered with respect to the electrodes of adjacent rows to enable a high fill of charge transfer without creating fabrication problems by spacing the fibers too close on adjacent electrodes.

Abstract: An electrophoretic display device includes a display element including a pair of first and second substrates which are opposed to each other, and a microcapsule enclosing a display material changed in optical characteristics in response to an electric impulse, the microcapsule being sandwiched between the first and second substrates; and a protective film sealing the display element. In the display device, a first electrode is provided on the surface of the first substrate which faces the second substrate, a second electrode is provided on the surface of the second substrate which faces the first substrate, and a spacer is provided in the space between the periphery of the facing surface of the first substrate and the first electrode.

Abstract: The image stability of electrophoretic media, comprising a plurality of particles disposed in a fluid and capable of moving through the fluid upon application of an electric field to the medium, can be improved by including in the fluid either a polystyrene or an aggregating diblock copolymer which forms micelle-like structures in the fluid, the diblock copolymer having a first block soluble in the fluid and a second block not swellable by the fluid. In variable transmission electrophoretic media, haze can be reduced by using as the fluid a mixture of a partially hydrogenated aromatic hydrocarbon and a terpene.

Abstract: A roller apparatus for a computer input device, such as a mouse, that has a sturdier support than prior art supports. A scrolling wheel carriage is supported by a PCB for greater stability. An open hook support for the hinge of a wheel carriage angles outward below a retaining point for the hinge. This combines with the hinge being hollowed out, so that upward forces due to variations in PCB thickness cause the hinge to compress while retained by the hook support. The design also provides long side arms for activating microswitches for lateral scrolling, and stoppers for preventing forward and backward slippage.

Abstract: The present invention relates to a system for enabling a platform to interact with a user. In a preferred embodiment, data corresponding to body motions of the user is first being detected and recorded by the use of a plural inertial sensing modules, and then the recorded data of body motions is processed and converted into a control signal to be transmitted to the platform by a communication module for controlling the platform to perform movements identical or corresponding to the recorded data of body motions while enabling an image display module to emulate the recorded body motions and display the emulated images on a monitor. By the interactive control system of the invention, not only a platform can be controlled to synchronize and interact with body motions of a user in a high-precision and high-mobility fashion, but also it can provide an instant visual feedback to the user of the platform so as to enhance the interactive effect of the platform.

Abstract: Apparatus for covering a portable computer of the type provided with a touch screen as an alternative to a keyboard. A rectangular fabric bag has an opening at one of the smaller ends of the rectangle for receiving the portable computer. The bag includes a fabric surface sensitive to the manual application of pressure, key positions defined on the fabric surface and a control circuit for identifying mechanical interactions to generate output data. The portable computer includes an interface and executable instructions for interpreting said output data. The interface may be a mechanical interface or a radio interface.

Abstract: A system and method for mixing a data file in a portable electronic device (100), to modify the output of the data file, are provided. The portable electronic device includes a user interface (102), a filtering module (202), and a processing module (204). The user interface is configured to receive inputs through a physical motion. The filtering module is configured to provide at least one filter effect to the output of the data file. The processing module is configured to interpret the physical motion and to modify the output of the data file. The processing module is operatively linked with the user interface and the filtering module.

Abstract: According to one embodiment, a key input device and a key input method thereof are disclosed. A key input device 1 is provided which sets a plurality of meanings by the operation with one input key. There are provided both or one of a guard section Gk after a judgment section Hk for selecting the meaning where the meaning corresponding to the preceding judgment section Hk is output by a setting operation for performing the selection, and a subsequent cancel section Ck where the transition procedure of the judgment sections Hk can be canceled halfway. The setting of undesired information is avoided even if there is caused a delay in the setting operation. The setting operation of the plurality of judgment sections Hk transiting in a time-series manner can be canceled in the middle of the transition.

Abstract: A haptic display includes at least one haptic device that can give tactile feedback instead of visible feedback. Each of the haptic devices converts a signal from a signal producing unit into force or tactile pattern. The haptic device does not require a large mass, so that it can be provided on almost any portion or part within the body of a mobile apparatus. For example, the haptic device can be embedded under a touch panel display that constitutes both input and output device. By providing the haptic devices under respective menu/function button areas displayed on the touch panel display, it is possible to stimulate the specific button in response to the user-input-operation, thereby directly providing the tactile feedback to the user's finger touching the corresponding button.

Abstract: Haptic feedback interface devices using electroactive polymer (EAP) actuators to provide haptic sensations and/or sensing capabilities. A haptic feedback interface device is in communication with a host computer and includes a sensor device that detects the manipulation of the interface device by the user and an electroactive polymer actuator responsive to input signals and operative to output a force to the user caused by motion of the actuator. The output force provides a haptic sensation to the user. Various embodiments of interface devices employing EAP actuators are described, including embodiments providing direct forces, inertial forces, and braking forces.

Abstract: The present invention relates to a micro-optical pointing device suitable for mobile terminals such as a cellular phone and PDA. A disclosed pointing device includes a light source emitting light rays to a subject; a contact member comprising a lattice type or perceivable pattern, which reflects an image of the moving subject; and an automatic transfer device restoring the contact member moved by a finger. The pointing device may further include a flip chip containing an image sensor, which converts the acquired image into an electronic signal, and a circuit for signal processing. The pointing device may include an integrated optical structure comprising a condensing lens, a specular surface, a light output part, and an image-formation lens. The pointing device may include a light guide structure that a parallel light prism lens, an image-formation lens, and a mask for blocking disturbance ray are formed into a single part.

Abstract: A computer system includes a computer, a calibration module, an event detection module, and an application interface module. The computer executes one or more applications and receives pointing device events generated by a pointing device connected to the computer. The calibration module modifies a rate of movement of a cursor displayed by the computer in response to the pointing device events. The event detection module detects a less-than-optimal calibration indicator from the pointing device events and modifies the rate of movement of the cursor. The application interface module communicates with the application being performed on the computer. A storage module for storing calibration information may also be included.

Abstract: An information input system includes a projector capable of projecting an operation screen image for making an input operation of information to a computer, and an image pickup device capable of sending picked-up image data acquired by picking up the operation screen image to the computer, wherein, as a predetermined position on the operation screen image is designated with a designating unit as the input operation, the designated position is detected as an input operation position on the basis of the picked-up image data, and a pointer is displayed at the detected input operation position by the projector.

Abstract: A method, apparatus, and medium for suspending repeated signal input using a slope variation in a tilting interface are provided. In the method of suspending a repeated signal input using a slope variation of a hand-held device in implementing a tilting interface of controlling a predetermined signal based on tilting of the hand-held device, the method includes measuring a slope of the hand-held device, calculating a slope difference between the measured slope and the previous slope, modifying the value of a determining factor that is used to determine whether to generate or to input the predetermined signal, according to changes in the measured slope and the calculated slope difference, and generating or inputting the predetermined signal or suspending the generating the predetermined signal based on the modified value of the determining factor.

Abstract: A method of enabling a user to initiate an action via a printed substrate, said substrate comprising user information and coded data, said coded data being indicative of a region identity associated with the substrate and of a plurality of locations on the substrate, said method comprising the steps of: receiving, in a computer system and from a sensing device, mode data and interaction data, the sensing device being operable in a plurality of modes and the mode data being indicative of one of said modes, the interaction data being indicative of the region identity and at least one position of the sensing device relative to the substrate, the sensing device generating the interaction data, when operatively positioned or moved relative to the substrate, by reading at least some of the coded data; identifying and retrieving at least part of a page description corresponding to the printed substrate using the region identity; determining a mode of the sensing device using the mode data; identifying an action usin

Abstract: Acceleration and attitude angles are measured by sensors mounted on a moving object and the measurement results are collected (step S21, step S22). The measurement results of acceleration are separated into low-frequency acceleration components and high-frequency acceleration components (step S24), and a time-rate-of-changes of attitude angles are calculated based on the measurement results of the attitude angles (step S25A). After finishing extraction of the high-frequency acceleration components and the low-frequency acceleration components, and finishing calculation of the time-rate-of-changes of attitude angles, the rotation contributing acceleration and translation contributing acceleration are estimated based on the high-frequency acceleration components, the low-frequency acceleration components, the attitude angles and the time-rate-of-change of attitude angles (step S26A).

Abstract: A roller for a control device includes a roller wheel having an outer portion formed of metal and a corrugated surface; a pivot arm configured to pivot in a first direction to contact the corrugated surface and to pivot in a second direction to move away from the corrugated surface; and energy driven means configured to pivot the pivot arm.

Abstract: Disclosed herein are a system and method for simultaneously reporting changes in location and orientation of an object moving over a planar surface and forming part of a computer input device, interoperably with a conventional mouse where reporting only location is in question. Further the present invention provides improved ways of user interaction with computer displays of two and three dimensional data and structures.

Abstract: The present invention includes a silent mouse with tactile feel for use in association with a computer. The mouse comprises a housing having a lower surface and an upper surface with walls therebetween, to define a chamber for housing the electronic components, and left and right buttons on the upper surface. Silent non-snap micro switches are located within the housing beneath the mouse buttons, to eliminate noise associated with conventional mouse snap micro switches, and also to provide the tactile feel of conventional mouse snap micro switches. The left and right buttons are either of transparent or translucent material and contain a left and right light associated with the left and right buttons. Depressing the left and rights buttons simultaneously actuates the associated lights, thereby providing a further indication that the appropriate mouse button has been selected and depressed.

Abstract: An optical mouse and an optical structure of the optical mouse, wherein the optical mouse comprises a casing, an optical structure and a circuit board. The optical structure is mounted inside the casing. The optical structure includes a lens set, an LED luminous element, a laser luminous element and an image-detecting element. The laser luminous element and the LED luminous element are mounted on the lens set and are opposite to each other or perpendicular and adjacent to each other and have an included angle with the horizontal plane. The circuit board is disposed inside the casing and is electrically connected to the LED luminous element, the laser luminous element, and the image-detecting element respectively for driving the optical structure; whereby the optical mouse is suitable for operating on any kind of surface.

Abstract: A dustfree and waterproof rolling-ball optical mouse comprising: a concave housing (1); a rolling ball (3) movably engaged with said concave housing; a dustproof gasket (2) fixed on the concave surface of the concave housing; a leakage hole (22) of a conduit (4) defined in a center of said concave surface of said concave housing; an aperture (21) for allowing light through which is eccentrically defined in the bottom of said concave surface of said concave housing; and a waterproof tab (28) formed around the edge of said aperture.

Abstract: A touch keyboard is provided, which mainly includes a touch panel to be sensed and actuated by touching with fingers and other objects, so as to execute instructions. A light-emitting display interface is mounted and integrated with the touch panel corresponding to a position sensed on the touch panel, and the corresponding position sensed on the touch panel is displayed through a light-emitting diode of the light-emitting display interface, such that the touch keyboard has the same function of inputting characters as that of an ordinary keyboard, and the output data sensed is then transmitted to the microprocessors, cell phones, or other products requiring an electronic key-in interface through a transmission device connected to both the touch panel and the light-emitting display interface, wherein the transmission device acts as a transmission interface between the touch keyboard and microprocessors, cell phones, or products requiring a key-in interface.

Abstract: A handheld data processing device having three functional components assembled in a sliding configuration. A processor module is mechanically coupled to two sliding covers. The processor module houses circuits for performing the functions of data processing and may also include a display and input/output functionality. The two sliding covers provide protection for the processor module and may include input/output transducers such as a keypad, speaker or microphone. Embodiments of the handheld data processing device include a handheld computer, wireless telephone and handheld video display. Used as a telephone, the sliders may house a speaker and a microphone.

Abstract: A remote controller device includes a transmitter; a pair of increasing and decreasing keys to increase and decrease a channel by a predetermined width; a switching key which switches the predetermined width corresponding to the pair of increasing and decreasing keys; and a controller which increases or decreases the channel by the predetermined width if the increasing key or the decreasing key is pressed, and transmits an increasing or decreasing signal to increase or decrease the channel by a wider width than the predetermined width if the increasing key or decreasing key is pressed when the switching key is selected.

Abstract: A function of emitting a color depending on a state of a mobile communication terminal is implemented. To do this, a keypad of the mobile communication terminal is illuminated with a color corresponding to a sensed result when a predetermined operation or event occurs. In order to illuminate the keypad according to a state of the mobile communication terminal using different colors, a keypad illumination unit includes a light source for generating a plurality of colors and a waveguide layer for diffusing light generated by the light source. Accordingly, a user can easily recognize a state of the mobile communication terminal through a color emitted through the keypad, and interest and convenience of the user can be satisfied with the mobile communication terminal emitting various colors.

Abstract: The number of operation keys is normally on the order of 12 to 20, corresponding to numeral keys and specialized keys, even for a portable telephone device capable of sending signals to, and receiving signals from, the Internet. In order to input Japanese language characters, including kanji, and specialized characters as data, a complex operation is necessary for switching the input mode. With the present invention, display devices are formed in operation keys for inputting information to electronic devices such as portable information terminals, typically portable telephone devices, and information terminals, typically personal computer or stationary telephone devices. A user is able to recognize the operation keys by characters, symbols, and numerals displayed in the operation keys by the display devices. The user is able to recognize the operation keys even in a dark location in accordance with the present invention.

Abstract: An input apparatus 100 has a sensor section 101 that detects whether a pressing operation or a touching operation is being performed on the front surface of a panel with a detected data value that varies when the pressing operation or the touching operation is performed, a position determination process section 102 that generates a control signal corresponding to the detected data value, and a control section 103 that generates a signal waveform of a drive voltage supplied to a drive section 104 to deform the panel with the control signal. When the operator performs an input operation, after the pressing operation or the touching operation is performed until the pressing operation or the touching operation is confirmed, the panel is deformed corresponding to a signal waveform having a small amplitude. After the pressing operation or the touching operation is confirmed, the panel is deformed with a signal waveform having a large amplitude.

Abstract: An electronic device and method providing a touch-based interface for a display control is provided. The electronic device includes a display, and a processing unit. The display includes a screen installed with a cursor thereon and a frame attached to the screen. The frame further has a first touch sensitive region and a second touch sensitive region for generating sensing signals in response to an input operation. Each sensing signal is assigned a coordinate for identification. The processing unit identifies the sensing signals according to the coordinates assigned therewith, controls a movement of the cursor displayed on the screen if the identified sensing signals from the first touch sensitive region, and controls a movement of pages displayed on the screen if the identified sensing signals from the second touch sensitive region. A related method is also provided.

Abstract: An indication of interaction with a touch-sensitive display is provided. A soft key is displayed on the touch-sensitive display. Contact with the touch-sensitive display corresponding to interaction with the soft key is detected. The periphery of the soft key smoothly changes in optical intensity in response to detecting the contact.

Abstract: Movement of a point of contact by a user of a touch-sensitive display is determined. In response to the movement, a list of items on the touch-sensitive display is scrolled through. The scroll through is accelerated in response to an accelerated movement of the point of contact. The scroll through and acceleration of the scroll through may be in accordance with a simulation of a physical device having friction.

Abstract: A game apparatus includes a first LCD and a second LCD, and a touch panel is provided on the second LCD. A question screen is displayed on the first LCD, and an operation screen for answering the question is displayed on the second LCD. On the question screen, a plurality of points are connected by a connecting line to display figures, characters, symbols (figure, etc). The operation screen displays a figure, etc. displayed on the question screen with a part of the connecting line thereof erased. A player performs an operation on a touch panel so as to display a figure, etc. the same as the figure, etc. displayed on the question screen. The player touches the touch panel to determine a drawing start point, the determination area of a point to be connected with thereto is set to become large while the determination area of the point not to be connected thereto is set to become small.

Abstract: A mobile apparatus for providing a user interface and method and medium for executing functions using the user interface are provided. The mobile apparatus includes a user interface module sensing a user's touch and providing information regarding the user's touch, and a control module determining a type of mode and function selected by a user based on the provided information regarding the user's touch, wherein the user interface module provides a user interface pad by which mode items and function items corresponding to the mode items are simultaneously formed, and the user interface module includes a first area for selecting mode items corresponding to the type of mode and function determined by the control module, a second area for selecting the function items, and a common area of the first and second areas, and the control module executes a function positioned at the common area.

Abstract: A system and method for changing data displayed on a touch-sensitive display screen. The present system and method recognize handwritten strokes made with a stylus on the touch-sensitive display screen of a PDA or palmtop computer in order to alter or correct displayed data. In one mode of operation, computer controlled association of the location of the handwritten strokes on the display screen with one or more of the displayed characters will result in automatic replacement of those characters by the handwritten strokes. In a second mode of operation, matching at least one of the handwritten strokes with one character of the displayed data will result in replacement of one or more characters of the displayed data with the handwritten characters. With the present system and method, the number of steps required to alter displayed data is reduced to the number of handwritten strokes. A significant reduction in time and effort as well as simplification in application is therefore offered.

Abstract: An input device, e.g., for a motor vehicle, includes: a display for the visual representation of an operating element; a touch screen disposed above the display for detecting a touching contact of the touch screen in the region of the operating element; and a control system for displacing the operating element, represented with the aid of the display, according to a touching motion across the touch screen, and the input device including an actuator for deflecting the touch screen when the operating element attains a predefined position or is moved a predefined distance.

Abstract: An input device, e.g., for a motor vehicle, includes a display for displaying variable information, and a touch screen, disposed above the display, for inputting instructions by touching the touch screen, and the input device including a control system for generating a selection marking displayable on the display, and for displacing the selection marking displayed by the display according to a touching motion across the touch screen.

Abstract: The invention relates to an input device, especially for a motor vehicle, wherein the input device comprises a display, a touch screen arranged above the display and having an operating surface, an actuator for moving the touch screen in at least one direction, and a control unit for visually representing changeable operating information and operating elements on the display for detecting a position of a touching of the operating surface and for the haptic feedback by controlling the actuator, wherein a file or a data set is stored in the control unit or in a memory assigned to the control unit, said file or data set comprising graphical information for representing at least operating information or at least one operating element and also control information for a haptic feedback assigned to the operating information or to the operating element.

Abstract: A display module comprising a display screen; a controller, said controller having an input for receiving information, and an output coupled to said display screen for outputting display information to said display screen; said controller including a component for determining an area of interest on said display screen; and said controller having a component for dimming at least a portion of said display screen outside of said area of interest.

Abstract: A portable electronic device. The portable electronic device includes a body, an input module, a display device, and a solar charging system. The input module movably connects with the body and comprises an opening. The display device is disposed on the body. When the display device is partially covered by the input module, the display device is for displaying a first image through the opening, and when the display device is not covered by the input module, the display device is for displaying a second image. The solar charging system includes a solar panel, surrounding the opening, disposed on the input module on a side between the input module and the display device.

Abstract: A mobile terminal unit that includes: a display section that displays thereon content data; a manipulation section that is provided close to the display section for being in charge of manipulation related to the content data; a pad section that detects the movement of an object on the display section and the manipulation section; anda control section that goes through a predetermined process with respect to the content data based on the movement of the object detected by the pad section.

Abstract: A system is provided for wirelessly transferring at least one data file in response to a detection of a flick gesture performed by a user. An electronic device to receive at least one data file from a handheld computing device. The handheld computing device includes (a) a display to display an icon corresponding to the at least one data file; (b) a touch screen to detect that an area of the display associated with the icon corresponding to the at least one data file is touched by a finger of a user; (c) a processor to determine whether the flick gesture is performed by the user; and (d) a communication element to transfer the at least one data file from the handheld computing device to the electronic device in response to the detected flick gesture. The flick gesture comprises the user touching the icon with a finger and then sliding the finger quickly across the display in a motion that feels to the user as if he or she is flicking the icon off the screen and to the electronic device.

Abstract: The invention proposes a touch-sensitive faceplate (18) comprising: a horizontal upper panel (32); means (34) for locating the point (P) of contact of a pointing element (30) on the upper face (32s) of the upper panel (32); and means for detecting at least one control action, independently of the location of the point of contact (P) on the upper face (32s) of the upper panel (32), characterized in that it comprises means (48, 52) for producing a mechanical impulse of a vertical principal orientation on the upper panel (32), when the value of the pressure (F2) is greater than or equal to the threshold value and that is transmitted to the pointing element (30) to generate a tactile sensation in response to the control action.

Abstract: A touch input device includes two or more interleaved scroll sensors. A common area is interposed between two of the scroll sensors. A sense line snakes through the common area. Scrolling pressure applied to a sense layer causes the sense layer to contact and electrically connect the sense line to the scroll sensors thereby permitting the scrolling pressure position to be determined by measuring a voltage on the sense line. The scroll sensors are potentiometric and may be linear strip scroll sensors or rotary ring scroll sensors. The interleaved scroll sensors with the common area allow smooth scrolling action from one major leg to another major leg.

Abstract: Embodiments include a method, a manual device, a handheld manual device, a handheld writing device, a system, and an apparatus. An embodiment provides a system. The system includes a manual device that includes a writing element operable to discharge a marking substance on a surface in response to a movement of the writing element upon the surface. The system also includes a sensor operable to acquire information corresponding to an environment of the manual device. The system further includes a verification module operable to determine a correspondence between a first aspect of the environment of the manual device and a second aspect of the environment of the manual device.

Abstract: A position input device is provided in which signals are transmitted from a position indicator, and signals transmitted from the position indicator are received by a position detector device. According to certain embodiments, an electrical double-layer capacitor, a charging circuit which charges the electrical double-layer capacitor, and a power transmission unit which relays and supplies to the charging circuit power supplied from a power supply unit external to the position indicator, are provided in the position indicator. In other embodiments the position input device has a built-in power supply unit, transmitting units, and a control unit for switching the transmitting units between energized and de-energized states. Also provided are position input systems and computer systems including the position input device, and methods of operating the position input device and the systems.

Abstract: A portable device having rotatable input buttons and a method of operating the portable device are provided. The portable device includes a button rotation detecting unit, a User Interface (UI) generating unit and a mode setting unit. The button rotation detecting unit detects the rotation of the input buttons. The UI generating unit generates desired objects. The mode setting unit changes a current mode of the portable device to a mode of operating on the objects corresponding to the positions of the rotated input buttons when the rotation of the input buttons is detected.

Abstract: An exemplary image driving circuit (300) includes a differentiating circuit (326), a random access memory (RAM) (322) connected to the differentiating circuit, a decoder (323) connected to the RAM, and a digital/analog (D/A) converter (324) connected to the decoder. The differentiating circuit receives a still image signal or a moving image signal at any one time. The differentiating circuit is further configured for providing the still image signal through the RAM, the decoder, and the D/A converter to a display device, and for providing the moving image signal through the D/A converter to the display device. The RAM is configured for storing the still image signal. The decoder is configured for decoding the still image signal. The digital/analog (D/A) converter is configured for transforming the still image signal to a plurality of driving voltages and transforming the moving image signal to a plurality of driving voltages.

Abstract: An image display device includes two data signal line drive circuits and two scan signal line drive circuits configured differently from each other. Different data signal line drive circuits and scan signal line drive circuit are compatible with different display formats. A display can be produced in the most suitable display format, and power consumption also can be reduced, by switch operating drive circuits according to the kind of input video and environmental conditions. Further, an image can be written over another image by writing video signals to signal lines with a time lag using a plurality of drive circuits; therefore, a superimposed display can be produced without externally processing the video signals. Thus, both a satisfactory image display and low power consumption can be achieved in an image display device.

Abstract: Provided are a driver that corrects a distorted image signal and a display device including the driver. The driver includes a control voltage signal generator which converts the voltage level of a control voltage signal according to an external signal, a clock signal generator which generates a clock signal whose duty ratio changes according to the voltage level of the control voltage signal, and a DC-DC converter which converts the level of an input voltage according to the duty ratio of the clock signal supplied from the clock signal generator and outputs the input voltage whose level is converted as a driving voltage.