|Friday, 16 February 2007|
Generally speaking, a camcorder is an electronic movie camera system comprising essentially three parts, a video cassette recorder (VCR) for recording a video signal of an object being imaged, a camera for imaging the object and a view finder for monitoring the resultant video picture. A camcorder records on magnetic tape the image of an object to be photographed, and is equipped with a display through which the object photographed can be confirmed. The camcorders are produced in the standard VHS, BETA and 8 MM formats used in home video cassette recording units. Camcorders are constructed primarily for the consumer market and therefore the size and structure tend be small and compact. Camcorders are relatively inexpensive products, which has contributed significantly to great acceptance by individual users for home video recording. Camcorders utilize sophisticated circuitry and optics in an attempt to achieve recording capabilities comparable with professional video equipment. Typically a camcorder includes a viewing device, or viewfinder, for viewing the scene, which may additionally be utilized for reviewing recorded material. Most viewfinders use liquid-crystal display devices for viewing the objects being photorecorded, in which a user can watch record image signals of the camera or playback signals of a video tape recorder through an external monitor. The recording section may utilize a magnetic tape recording medium, magnetic disk, or solid state memory. A camcorder normally has a unidirectional condenser microphone for simultaneouly sound recording. Audio signals are captured by the microphone and amplified by amplifier which may generate an audio modulated signal for recording and include a demodulator for audio reproduction and output coupling. The luminance and coloring signals are also processed by a record and play back amplifier which generates signals for recording and reproduction by heads mounted on the periphery of head drum. The camcorder is controlled by a microprocessor which operates in conjunction with a recorder mechanism controller. The complete camera and recorder may be battery powered, often by a rechargeable battery.
Video camcorders are mainly classified into those of the analog type camcorders and those of the digital type camcorders. In analog camcorders video recording and reproduction are processed in an analog regime, while in digital type camcorders, video recording and reproduction are processed in a digital regime. In analog camcorders, the audio signals of the shooting scenes are recorded in the audio channel on a recording tape during the shooting mode, and then these audio signals are erased and other audio signals are recorded in the audio channel during the dubbing mode. Digital video camcorders can interface with a personal computer via a personal computer interface unit for digital video camcorders. Analog video camcorders can not interface with any personal computer because they have a format incompatible with personal computer interface units used for digital video camcorders to interface with a personal computer. The digital camcorder is designed to have a different construction from the MPEG considering the characteristics in that both an encoder and a decoder should be included in the camcorder. The digital camcorders produce digital video images which may be digitally manipulated and displayed. In digital and analog camcorders, audio signals may be recorded on a recording media during a shooting mode and during a dubbing mode. In camera signal processing for a camcorder, when the optical image of a target to be photographed is formed on a CCD, this CCD converts it into an electric signal, which is then processed into an analog signal. This analog signal is finally displayed or recorded on a recording medium as the target image. During the shooting mode, video signals are shot and audio signals in the shooting area are recorded at the same time. During the dubbing mode, audio signals, in addition to the audio signals recorded during the shooting mode, are artificially recorded. Camcorders typically utilize a solid state imager. The imager generates an image signal which is processed to form a video signal for television viewing or recording. Imaging systems have broad applications in many fields, including commercial, consumer, industrial, medical, defense and scientific markets. A CCD is a two-dimensional array of sensors each of which produces a charge as a function of the quantity of photons it absorbs. After an image is exposed on a CCD, the pixels are shifted vertically to a line charge register and this line shifts the pixels horizontally to the output.
A video camcorder has the function of a general video camera for imaging an object as well as the function of a video recorder for recording the image of the object. A camcorder records image information of an object inputted therein through a camera on a recording medium thereof such as a magnetic tape. The recorded object image may be displayed through a view finder or liquid crystal display window mounted to the video camcorder or an external display device such as a television. A camcorder encodes an image of an object into a video signal and records the encoded video signal on a recording medium such as a video cassette tape. Recording of a camcorder is performed beginning with selection of a recording button by the user upon power-on of the camcorder. The user images a desired object and then records the image of the object onto a recording medium. The user can subsequently view the image recorded on the recording medium by reproducing that image. A user can confirm the operational status of equipment in use by displaying characters on a display device such as a monitor or an electronic viewfinder. The user can also select a desired function using the displayed characters.
Camcorder is powered by a rechargeable battery cartridge or power pack such as a rechargeable lithium ion cartridge. Such a rechargeable battery is made to join or separate from the main body of the camcorder by a coupler. In order to properly function in a camcorder, the camcorder battery pack must have both mechanical and electrical compatibility with the camcorder in which it is used. Currently battery packs use rechargeable batteries such as lithium ion or nickel cadmium batteries. Such battery packs generally comprise an insulated housing designed to fit and lock in place within a receiving cavity within the imaging device to be powered, and a structural mechanism for attaching the battery pack to an electronic device in such a manner that electrical energy may be continuously supplied from the battery to the electronic device. The negative and positive terminals on the battery housing are oriented to contact negative and positive contacts, respectively, within the device to be powered. Battery power consumption is greatest when recording, and increases further with frequency of zoom lens and iris operation.