Abstract: A radiating coaxial cable transmission line that may be used as an antenna. Mechanisms are incorporated for boosting the rate of conversion of bifilar mode to monofilar mode.

Abstract: There is disclosed an antenna device comprising an elongate dielectric radiating element having a longitudinal axis and a feeding mechanism for generating displacement currents in the dielectric radiating element. The radiating element is configured to support displacement current resonance modes parallel to the longitudinal axis but to inhibit displacement current resonance modes transverse to the longitudinal axis.

Abstract: The program of the present invention is an image processing program for causing a computer to display images using a plurality of display devices, wherein the image processing program causes the computer to perform the steps of: (a) dividing a virtual space into a plurality of areas; (b) associating display device selection information with each of the plurality of areas for selecting on which of the plurality of display devices an image is to be displayed; (c) judging in which of the plurality of areas a mobile object existing in the virtual space is positioned; (d) acquiring the display device selection information associated with the area in which the mobile object is positioned; and (e) displaying the mobile object in a display device corresponding to the display device selection information acquired at step (d) among the plurality of display devices.

Abstract: A liquid crystal matrix display includes a matrix driver delivering at least a first frame section signal and a second frame selection signal and a first write device and a second write device associated with each pixel element of the matrix, wherein one of the write devices is connected to the associated selection line of the pixel element, and the other is connected to another selection line of the matrix. The write devices have crossed sample and transfer commands, the first frame selection signal causing sampling in the first write device, and contacting of information already sampled in the second write device with the pixel element, the second frame selection signal causing sampling in the second write device, and contacting of information already sampled in the first write device with the pixel element.

Abstract: A display screen is controlled through successive scans of the display screen. Each scan of the display screen includes a successive selection of rows of the display screen. For each row selected, and in accordance with a normal selection, a first column selection mode is implemented wherein a first selection signal is generated for the column, that first selection signal going from a first state towards a second state with an intermediate plateau level therebetween. In an alternative operation, a second column selection mode is provided which replaces the first column selection mode, the second column selection mode including the generation of a second selection signal going from the first state to the second state without any intermediate plateau level. At least at the start of each scan, the first selection mode is replaced by the second selection mode and this second selection mode is maintained for a given column, at the latest, for as long as no deselection of the column has been effected.

Abstract: An image display apparatus of the present invention comprises: a plurality of pixels for displaying an image on a screen; and a drive unit for outputting a drive signal for driving the plurality of pixels by interlace, the drive unit including a correction value outputting circuit for outputting a correction value for correction for suppressing a deterioration of image quality due to crosstalk and an outputting unit for outputting the drive signal corrected by the correction value, wherein the correction value is calculated based on pixel data corresponding to at least one pixel proximate to a pixel which is objective for correction and the pixel data used for the calculation includes pixel data in a field in which the pixel which is objective for the correction is driven and pixel data in a field in which the pixel which is an objective for the correction is not driven.

Abstract: Provided is a plasma display apparatus having largely improved luminous efficiency while restraining cost increase of its driving circuit. A PDP 1 has an outer case formed by attaching a front panel 10 and a back panel 40, with barrier ribs 30 formed therebetween. Besides, a space created between the front panel 10 and the back panel 40 is filled with a rare gas such as Ne, Xe, and He. On the back panel 40, data-sustain electrodes 52 and data electrodes 51 are aligned alternately and parallel to each other. In a write period, a data driving circuit 4 performs selective data voltage output to the data electrodes 51 based on image data inputted for each subfield line by line. In a sustain period, a data-sustain driving circuit 5 performs collective data-sustain pulse application to the data-sustain electrodes 52.

Abstract: One field period is structured of a plurality of subfields (SF), each including an initializing period, writing period, and sustaining period. Performed in the initializing period of each SF is all-cell initializing operation for generating initializing discharge in all the discharge cells to be used for image display, or selective initializing operation for generating initializing discharge in the discharge cells having generated sustaining discharge in the preceding SF. The period allocated to the writing discharge in a SF for the all-cell initializing operation is set shorter than the period allocated to the writing discharge in a SF for the selective initializing operation. This structure provides a plasma display panel driving method and a plasma display device capable of inhibiting increases in black picture level and displaying images at excellent quality.

Abstract: A plasma display device is provided including: an ambient temperature detector which detects an ambient temperature; a display load factor detector which detects a display load factor; a sustain pulse number determiner which determines a sustain pulse number based on the ambient temperature and the display load factor; and a plasma display panel which performs display according to the determined sustain pulse number.

Abstract: The invention provides for a method and display apparatus (10) having driving circuitry for driving a display panel (24) having a plurality of addressable discharge cells (26) driven by display pulses (DP), including the steps of applying data pulses (DAP) during the time interval between display pulses (DP) and characterized by the step of priming charges for each of the discharge cells (26) by means of the reset discharges so as to reduce the required data voltage, and in particular such a method wherein one TV-field period (TF) is divided into a plurality of sub-fields (SF) all of which are of substantially equal time durations.

Abstract: Initialization waveforms with different voltages are applied respectively to a predetermined subfield with a small number of sustain pulses, and a subfield with the smallest number of sustain pulses in subfields other than the predetermined subfield. This offers a plasma display device that achieves a correct write operation in all discharge cells even if discharge interference occurs between adjacent cells, and also achieves a high contrast.

Abstract: A plasma display device. A plasma display panel includes a plurality of address electrodes, a plurality of scan electrodes, and a plurality of sustain electrodes. A temperature detector detects a temperature of the plasma display panel. A controller outputs a scan electrode driving signal to control a reset waveform to be applied during reset periods of a first number of subfields when the detected temperature between a first temperature and a second temperature, and to control a reset waveform to be applied during reset periods of a second number of subfields when the detected temperature is lower than the first temperature and higher than the second temperature. The second number of subfields is greater than the first number of subfields. A scan electrode driver applies the appropriate reset waveform during a reset period of a subfield according to the scan electrode driving signal output from the controller.

Abstract: The present invention relates to a light emitting device for preventing a cross-talk phenomenon and a pectinated pattern. The light emitting device includes data lines, scan lines, pixels and discharging circuit. The data lines are disposed in a first direction. The scan lines are disposed in a second direction different from the first direction. The pixels are formed in cross areas of the data lines and the scan lines. The discharging circuit discharges respectively a first data line and a second data line of the data lines to a first discharge voltage and a second discharge voltage during a first sub-discharging time of a discharging time, and couple the first data line to the second data line during a second sub-discharging time of the discharging time. Here, the second discharge voltage has different magnitude from the first discharge voltage.

Abstract: A display device includes a substrate including a display region, and a reference voltage supplying unit disposed along at least one side of the display region which supplies a reference voltage to the display region, wherein the reference voltage supplying unit comprises; a first sub-supplying unit including a first voltage applying region which supplies the reference voltage to the display region, a first insulating layer disposed on the first sub-supplying unit, and a second sub-supplying unit disposed on the first insulating layer and including a second voltage applying region which supplies the reference voltage to the display region.

Abstract: An anode drive circuit is provided for each of organic EL elements constituting one row on a passive display panel. The anode drive circuit includes: a capacitor; two switches for permitting the capacitor to store charge by applying a charge voltage to a high-voltage terminal of the capacitor while holding a low-voltage terminal of the capacitor at a reference voltage; and two switches for permitting the capacitor to release charge stored therein by connecting the high-voltage terminal to an anode of an organic EL element while applying a voltage higher than a light emission threshold voltage of the organic EL element to the low-voltage terminal. The number of times of repetition of charge/discharge of the capacitor within one horizontal time period is controlled so as to control the light emission luminance of the organic EL element according to a data signal.

Abstract: A noisy signal analysis in which a threshold value is set to evaluate the presentation of the display device. The analysis can produce the range of noise level of the image for measuring the distortion block of image caused by the display devices. Furthermore, the apparatus includes a step function generator for producing step functions, a transforming unit for changing threshold value in step functions, and a display for showing the image corresponding to both the high value and low value.

Abstract: In an information display device having a display panel, wherein one or more kinds of display media are sealed between two opposed substrates, at least one of which is transparent, and wherein the display media, to which an electrostatic field is applied, are made to move so as to display information such as an image or the like, a dummy rib 11 having a cross-sectional shape (any one of L-shaped, U-shaped, rectangular, circular, polygonal, semicircular, I-shaped or step-like shape, a L-shaped partition wall is shown) capable of preventing outflow of conductive paste from a regular applying position has been provided at a predetermined position on the substrate in order to prevent a short circuit between the substrates due to the outflow of the conductive paste applied to a peripheral part of the substrate to allow conduction between upper and lower substrates.

Abstract: Provided is an image display apparatus including: a screen, on which a plurality of pixels operating in a diffusion mode and a transmission mode are arranged; a light source unit which irradiates a plurality of single color lights sequentially onto the screen; and a driving unit which converts the operating mode of the plurality of pixels into one of the diffusion mode and the transmission mode according to image data, wherein the colors of the image data are separated in synchronization with the plurality of single color lights.

Abstract: Based on each of video data repeatedly supplied to a pixel, a signal processing section generates video data (Dd) for an image display period to be supplied to the pixel and video data (Db) for a blanking period to be supplied to the pixel, and outputs the video data (Dd) and (Db) in a predetermined order. Further, when a gradation transition from a gradation indicated by previous video data (D(i,j,k?2)) supplied to the pixel to a gradation indicated by current video data (D(i,j,k)) supplied to the pixel indicates an increase in luminance, a generating circuit for a blanking period of the signal processing section outputs video data indicative of a gradation which is increased compared with a gradation indicated by gradation data for a blanking period in a steady state, the video data thus outputted being regarded as video data (Db(i,j,k?1)) for a blanking period. This allows for providing a display device capable of displaying moving images with high quality.

Abstract: In order to provide a reflection type liquid crystal display apparatus where, even when the pixel size is small, the crosstalk between a signal line and an end of a capacitor can be decreased, thus resulting in a good output image, by forming a signal line 2 for transmitting an image signal to each pixel with a second metal layer, by placing a shield line 12 between a capacitor electrode 10 constituting a capacitor and the signal line 2 with a first metal layer, and by giving a fixed potential, shielding is provided to prevent occurrence of cross-talk. The capacitor is configured with a common electrode 11 and a capacitor electrode 10, having a diffusion layer formed on a semiconductor substrate. By placing the capacitor electrode having a diffusion layer formed on the semiconductor substrate and the common electrode having a fixed potential below the signal line, shielding is provided to prevent occurrence of cross-talk.

Abstract: A method for driving a flat display is disclosed. Each row of the flat display includes N pixels, that is used to display M pixel data in a row of a image frame, wherein M and N are positive integers and M is larger than N. The method includes, in a first time division, the N pixels display N pixel data out of the M pixel data, and in a second time division, the N pixels display the remaining M-N pixel data.

Abstract: A driving circuit (25) for a liquid crystal display connecting to a host is provided. The driving circuit includes an image memory (251), a comparator (253), a counter (255) and an image converting means (259). The image memory stores a former frame's image data. The comparator compares a latter frame's image data provided by the host with the former frame's image data. The counter has a predetermined first threshold value and is configured to record an ongoing number of consecutive frames during which a latter frame's image data are the same as a former frame's image data. The converting means inverts a latter frame's image data into inverted frame image data when the ongoing number reaches the first threshold value.

Abstract: An exemplary liquid crystal display (LCD) panel (22) includes a display area (251) and a non-display area (252). The non-display area has a photoelectric cell unit (254) provided thereat. The photoelectric cell unit is configured to generate electrical power when irradiated by light. An LCD device using the LCD panel, and a mobile phone using the LCD device, are also provided.

Abstract: An image projection apparatus is disclosed which projects an image having a good color by reducing the influence of a lateral electric field in a liquid crystal display element (LCD). The apparatus includes three LCDs, each including two opposite electrodes. As the voltage applied to a liquid crystal layer is increased, retardation provided for light in each color band is increased. A controller controls an electrode application voltage in the first LCD such that, in a white display state, a liquid crystal application voltage (LCAV) in the first LCD is lower than the LCAVs in the second and third LCDs, and such that, in a black display state, the LCAV in the first LCD is higher than the LCAVs in the second and third LCDs and has a value from 1% to 30% of the LCAV in the first LCD in the white display state.

Abstract: A liquid crystal display for automatically adjusting brightness of interference image displayed at ECB sub pixels of quad type cells of a liquid crystal display panel in accordance with brightness of a background screen is disclosed. The liquid crystal display includes first to n-th look-up tables each holding a mapping of one first to n-th mappings of ECB brightness data to cell location information for the quad cells of the liquid crystal display panel; an image processor that calculates a brightness data distribution of an image; a viewing angle controller that selects one of the first to the n-th look-up tables depending on the calculated brightness data distribution; and a data aligner that combines the selected ECB brightness data with the input RGB data, and then aligns the combined RGB data and ECB brightness data for display in accordance with a quad cell structure.

Abstract: The present invention discloses a driving method for increasing gray level, wherein the PWM mode is added into the FRM mode, and the PWM mode is implemented with the common drive circuit; the section of the horizontal synchronous signal of a frame interval is divided into multiple sub-sections according to the requirement of the PWM mode; the control of the length of the turn-on period within a frame interval is implemented with a redesigned control circuit, and none special drive circuit is needed.

Abstract: A method of driving a liquid crystal device having an optically compensated bend mode and including an image display area including a plurality of pixels two-dimensionally arranged in a row direction in which a plurality of scanning lines extend and in a column direction in which a plurality of data lines extend. The method includes performing an initial transition of a liquid crystal alignment from a splay alignment to a bend alignment. The initial transition includes inversion driving for driving the plurality of pixels by using, among a plurality of inversion driving modes, one inversion driving mode for inverting relative polarities of voltages applied to the plurality of pixels, and different inversion driving for switching the inversion driving mode in the inversion driving to a different inversion driving mode before driving the plurality of pixels.

Abstract: A display control system for a multi-layer display system including at least one multi-layer display unit (6). A multi-layer display unit includes multiple stacked or overlapped display layers (1a, 1b, 1c, 14, 15) each adapted to render display elements (2, 16B, 17B, 18B) thereon for viewing through the uppermost display layer. The level of difficulty for a user to view an overlapped image differs depending on the colour, brightness or type of images (for example text-on-text) being displayed and also the layer in which the image is being displayed and whether the image is currently active. At least any overlapping portion of display elements from different display layers are adjusted (automatically or by a user) in order to improve the viewing experience for a viewer. Types of adjustment possible include moving the images within their display layer or to an alternative display layer or altering their visual properties (such as colour, brightness, contrast etc).

Abstract: A light source includes a plurality of lighting elements arranged to illuminate different regions of visual perception. Circuitry coupled to the light source is configured to supply power to a first subset of the lighting elements according to a first waveform and to a second subset of the lighting elements according to a second waveform out of phase with the first waveform.

Abstract: A drive structure is provided for a sequential Red-Green-Blue (RGB) display. One light receiving means receives part of light output from R, G, and B light sources and performs conversion to a current signal. Each light source driver performs a control operation for maintaining the light intensity of each light source substantially constant by adjusting an amount of operating current applied thereto according to the magnitude of a feedback current provided from the light receiving means. Light is sequentially emitted by the light sources and received by the light monitoring device in response to input R, G, and B modulation signals.

Abstract: An exemplary pulse driving circuit (200) includes a pulse generator (210) configured for generating a pulse signal for driving the pulse driving circuit; a capacitor (220); an NMOS (negative metal-oxide semiconductor) transistor (230) comprising a gate electrode configured to be connected to the pulse generator via the capacitor, a drain electrode configured to be connected to a load circuit, and a source electrode configured to be connected to a DC (direct current) power supply (270); a current limiting resistor (240) connected between the gate electrode and the source electrode of the NMOS transistor; and a diode (250) comprising a positive terminal connected to the source electrode of the NMOS transistor and a negative terminal connected to the gate electrode of the NMOS transistor.

Abstract: An exemplary burning system (20) for a liquid crystal display includes a VGA (video graphics array) interface (230), a DVI (digital visual interface) (240), an interface-inverting circuit (220) configured for selectively switching between connectivity with the VGA interface and connectivity with the DVI, and a host computer (250) including a print interface (210). The host computer is configured for burning extended display identification data for the VGA interface into the liquid crystal display via the print interface, the interface-inverting circuit and the VGA interface, and is configured for burning extended display identification data for the DVI into the liquid crystal display via the print interface, the interface-inverting circuit and the DVI.

Abstract: The system of direct interaction between one or more subjects and at least one image and/or a video with dynamic effect projected onto an interactive surface includes an interactive station. The interactive station includes an integrated apparatus for the acquisition and processing of the information detected in the interactive area, and a covering shaped like a box able to be fixed on a surface perpendicular with respect to the interactive area in which the natural action of the person and the interaction between the person and at least one image projected by the projector is carried out. The interactive station of the wireless type incorporates a PC control unit, infra-red ray generators, and at least one video camera with a firewire card. The method of direct interaction includes managing the interactive system, managing networking and physical alignment, selecting interactive effects, tracing statistics, and performing a cluster function.

Abstract: An improved handheld electronic device has a case with an elongated cavity formed therein. An audio transducer is in fluid communication with the cavity, and a number of sound openings are formed in the case and are in fluid communication with the cavity and with the atmosphere surrounding the handheld electronic device. The sound openings are generally spaced from a central region of the audio transducer to space the sound openings generally farther from an edge of the case than the audio transducer. The cavity is configured to form a Helmholtz resonator that enables the communication of sound through the cavity between the audio transducer and the sound openings. The spacing of the sound openings from an edge of a case helps a user to form a seal between the case and the user's ear to enable sound from the sound openings to enter the ear and to be perceived by the user.

Abstract: Peripheral devices having one or more pedals are provided, wherein the peripheral devices are slip resistant with respect to a surface, such as a floor, upon which the peripheral devices are placed or positioned. A user of such peripheral devices can use a heel against the floor surface through the peripheral device to anchor the peripheral device and can use the heel to correct the position of the peripheral device if it slips by applying a counterforce. The peripheral device(s) include multiple springs per pedal and associated software for accommodating a non-linear force response for a more realistic user experience.

Abstract: An icon for indicating a person's personality type and a method for creating an icon that visually represents a person's personality type are disclosed. The personality type may be defined by the Myers-Briggs Type Indicator (MBTI). The method comprises selecting a shape based on the person's preferred approach to the world: a circle for a Perceiving preference and a square for a Judging preference. A vertical line is placed in the shape if the person is an Introvert and a horizontal line is place in the shape if the person is an Extravert. Colors are then filled into the two sections of the shape based on the person's mental functions: blue for iNtuitive, green for Sensing, red for Feeling, and black for Thinking. The resulting icon is specific to the person's personality type and is a memorable visual reference.

Abstract: Systems and methods according to the present invention address these needs and others by providing a handheld device, e.g., a 3D pointing device, which uses at least one sensor to detect motion of the handheld device. The detected motion can then be mapped into a desired output, e.g., cursor movement.

Abstract: A system and method for determining a motion vector uses both a main block from an image and at least one ancillary block relating to the main block from the image. The main block and ancillary block are then tracked from image to image to provide a motion vector. The use of a composite tracking unit allows for more accurate correlation and identification of a motion vector.

Abstract: An interactive game apparatus includes a game host and a game controller. The game host includes a game control module capable of running a game program and receiving at least one response signal outputted from the game control. The game controller includes a first motion sensor, a second motion sensor and a processor. The first motion sensor detects motion signals of the play, and the second motion sensor also detects motion signals. Furthermore, the processor includes a determination circuit determining the timing for activating either the first motion sensor or the second motion sensor.

Abstract: A wireless mouse includes a rotatable backdoor, a damper and a clasping member. The backdoor has an engaging element. The damper is mounted onto the lower base and includes a rotary member. When the clasping member is engaged with the engaging element, the backdoor is closed. Due to the rotational resistance provided by the damper, the backdoor can be slowly opened.

Abstract: A handheld wireless communication device configured to send and receive text messages. The device is hand cradleable with an elongate body configured to be held in one hand by an operator during text entry. A display is located on a front face of the body and upon which information is displayed to the operator during text entry. A key field is also located on the front face of the elongate body and that includes a plurality of alphanumeric input keys and menu control keys. A trackball navigation tool is located on the front face of the elongate body. The alphanumeric input keys include several alphabetic keys with letters arranged in a traditional (QWERTY), but non-ITU Standard E. 161 telephone letter layout. A microprocessor is provided that receives operator commands from the keys and the trackball navigation tool and which affects corresponding changes to the display based on user input.

Abstract: Visual and/or audible cues are used to assist users with data input on keyboards having keys associated with multiple input symbols or functions. Each input symbol or function has a correspondence to an input object, such as a finger. During key actuation, one or more input objects are detected. Candidate input symbols or functions are determined based on identification of the key being actuated. The candidate input symbols or functions are presented to the user in the form of cues having visual and/or audible features. The detected input objects may be optionally identified and presented to the user in the form of cues having visual and/or audible features as well.

Abstract: A computing device includes a touch-sensitive surface for receiving touch as input, and a housing structure having a tip segment that overlays the touch-sensitive surface. The tip segment forms a gap over the touch-sensitive surface. A first protective layer is positioned to contact the tip segment of the housing structure and the touch-sensitive surface so as to form an obstruction in the gap against intrusions.

Abstract: A portable communication device. The portable communication device comprises a touch screen, a key code generator, and a controller. The touch screen generates event information in response to a manipulation on the screen, wherein the event information specifies position information corresponding to the manipulation. The key code generator generates a key code corresponding to the event information according to the position information thereof, wherein the key code indicates an upward, downward, leftward, or rightward key code, and the key code does not correspond to any visual item displayed on the touch screen.

Abstract: A system and method for detecting at least two-finger input on a touch screen of a display such as computer, etc. includes a display screen; a sensing grid arranged for sensing touch on said display screen; a plurality of electrodes connected electrically to the sensing grid. A controller receives an output from the sensing grid, and a module identifies at least two points on the grid indicating locations of the display screen that have been touched by a user and identifies a geographic portion of the display screen to be identified based on said at least two points. As the position of the fingers are relative to the position of the screen via change in a direction of a Z-coordinate, a variable zoom can be provided by the sensing grid commensurate with different distances that the multiple fingers are sensed from the display screen.

Abstract: Provided are an apparatus, method, and medium for providing an area division unit having a touch pad function, and more particularly, an apparatus and method for providing an area division unit having a touch pad function which are capable of dividing a display screen of a display device into one or more display areas using an area division unit equipped with a transparent touch pad and allowing a user to choose and execute one of a plurality of menu items that are displayed on the display screen and are seen through the transparent touch pad. The apparatus includes an area division unit which can be moved in a predetermined direction by a user and can thus divide a display screen into one or more display areas, the display screen which is divided into one or more display areas according to the location of the area division unit, and a touch pad which is attached on the top surface of the area division unit and allows the user to choose and execute one of a plurality of icons displayed on the display screen.

Abstract: According to one embodiment, an information processing apparatus includes a display unit. A display portion is provided in the display unit. An antenna is provided in the display unit and radiates radio waves. When the display unit is used in a usage pattern where the antenna is located in a side of the display unit which side is closest to a user, a controlling unit controls a direction of an image displayed on the display portion not to correspond to a direction of the display unit.

Abstract: The object is to provide an image forming apparatus that can easily input a setting value associated with a fractional number from a keypad. In a fractional number input mode, if a numeric value (i) is input from the numeric keypad, it is determined whether the numeric value is within an input range set as a numeric value of an integer portion; if a next input numeric value (ii) can be both the one's place of the integer portion and a numerator of a fractional portion, (i) and (ii) are not determined; if both portions can be determined by a next input numeric value (iii), the integer portion displays (i), the numerator portion displays (ii) and “/”; and if the numeric value (iii) can only be a denominator, (i), (ii), and (iii) are defined as the integer, the numerator, and the denominator, respectively.

Abstract: A touch panel of the invention comprises a first panel having a first film base with transparency and a first transparent conductive thin film provided on one surface of the first film base; and a second panel having a second film base with transparency and a second transparent conductive thin film provided on one surface of the second film base, wherein the first panel and the second panel are arranged so as to face each other with a spacer therebetween, in such a manner that the first conductive thin film and the second conductive thin film face each other, wherein the surface of the first conductive thin film has a hardness of 1 GPa or more and a modulus of elasticity of 5 GPa or more, the surface of the second conductive thin film has a center line average roughness (Ra) of 0.3 nm to 1.0 nm, and that of the center line average roughness (Ra) of the surface of the second conductive thin film is smaller than that of the surface of the first conductive thin film. The touch panel has good durability.

Abstract: A roller structure for input devices with improvement is disclosed. The roller structure of the present invention comprises a roller, a supporting seat, an encoder, a circuit board, a contact switch and a roller supporting seat. The supporting seat is disposed within the roller, and a space is provided on one side of the supporting seat so that the encoder is fixedly disposed in the space and hence the roller structure has a smaller size. A contact switch is provided on the circuit board. Two positioning protrusions are provided on the outside of the supporting seat and two positioning tracks are provided on the roller supporting seat so that the movement of the supporting seat may be guided and limited by the roller supporting seat. An activation protrusion is provided on the two positioning protrusions and may activate the contact switch when the supporting seat is pressed down.