摘要:
A surface acoustic wave device has an electrode finger structure in which the width of finger portions external of envelopes indicating a weighted overlap length and the length of the spaces existing between adjacent finger portions measured widthwise thereof are substantially equal to one half of the wavelength of the acoustic surface wave, the envelopes are symmetric about the center line of a propagation path for the surface acoustic wave, and the finger portions and the spaces between the finger portions are in opposite positional relation to each other about the center line of the propagation path. With this electrode finger structure, occurrence of disturbing reflected signal at the weighted interdigital electrode, which is used as an input/output electrode of the surface acoustic wave device and occurrence of wavefront distortion are prevented and production yield of the device is improved.
摘要:
An auto-focus system for a video camera having a zooming function includes an auto-focus signal generator for generating an auto-focus signal of the video camera. In particular, unlike conventional systems, auto-focus is accomplished by moving a master lens of the zoom lens system. A motor is coupled to at least a part of the master lens for this, and a motor controller performs the auto-focus operation by controlling the motor in accordance with the auto-focus signal. Further, a switch is provided which is changeable selectively between a first and a second mode instructing photographing over a normal distance range and over a macroscopic range respectively. A master lens controller controls the motor controller to decide a movable range of the master lens in accordance with the selected mode of the switch and to thereby control the motor controller to move the master lens within the decided movable range.
摘要:
An auto-focusing system for a video camera using the focus signal extracted by a focus signal extracting device from high-frequency components of the video signal. A gate circuit is provided in front of the focus signal extracting device and the gate circuit is made conductive or non-conductive depending on the magnitude of the focus signal thereby to control the quantity of the video signal received by the focus signal extracting device, whereby the dynamic range of the focus signal extracting device is virtually expanded.
摘要:
An automatic focusing system for a video camera carries out automatic focusing on the basis of a focus signal extracted from a high-frequency component of a video signal. The automatic focusing system comprises at least one of picture-contents change detecting means for detecting a change, if any, between the contents of pictures of two consecutive picture periods on the basis of the output signal of a low-pass filter to which the video signal is applied, momentary change detecting means for detecting an abrupt change of the focus signal, and reduction-factor change detecting means for detecting a change between the contents of pictures of two consecutive picture periods on the basis of the output signal of a detector detecting the reduction factor of the lens system, so that the automatic focusing operation can be interrupted in response to the output signal of the change detecting means and can be restarted when the output signal is reduced to a level lower than a predetermined level.
摘要:
Disclosed is a video image printer for printing a video image of an input video signal onto a printing paper, in which a medium, such as a magnetic sheet disc or magnetic tape for a video cassette recorder, capable of recording/reproducing the information of the video image is employed. In order to obtain a reproduced video signal from the recording/reproducing medium with normal-operation, the video image printer is provided with a mechanical vibration-absorbing mechanism and an electrical reproduced signal correction circuit. Depending upon the requirements of the situation, a plurality of recording/reproducing heads are provided so as to make it possible to record a video image to be printed on the recording/reproducing medium during the printing operation of a previously selected video image.
摘要:
A television receiver provided with a circuit automatic tilt control circuit which can automatically correct the frequency response characteristic of the television signal. The television receiver comprises an SAW filter having one input electrode set and two output electrode sets, and a frequency response controlling circuit in which intermediate frequency signals delivered from the two output electrode sets of the SAW filter are added together and the amplitude of a summed intermediate frequency signal is varied. The frequency response of the frequency response controlling circuit is controlled by detecting the amplitude of the color burst signal such that the amplitude of the color burst signal is constantly invariable. In the event that amplitudes of the picture signal high frequency component and the chrominance subcarrier become excessive or insufficient, the amplitudes are corrected to correct values to ensure that high quality pictures can constantly be displayed on the screen of the television receiver.
摘要:
An electronic still camera including a shutter, an image sensor, a recording device for recording an output signal from the image sensor, a power source for supplying electric power to the image sensor and recording device, and a shutter button is disclosed in which immediately after the operation of the shutter button is detected, the shutter is made open and an optical image of a body to be imaged is formed on the light receiving surface of the image sensor in a state that scanning and reading operations for the image sensor are inhibited, the above state is maintained till the recording device reaches a recordable state, to accumulate an electric charge corresponding to the optical image in the image sensor for an open period of the shutter, and a scanning operation for the image sensor is started after the recording device has reached the recordable state, in order for the recording device to record the output signal from the image sensor.
摘要:
Applicants discovered that by employing selected transducer geometries, such as unbalanced dual-finger geometries, certain reflections, called "Mechanical electrical loaded" (MEL) reflections, can be generated which tend to cancel reflected waves inherently generated by surface acoustic wave devices.In particular, the disclosure is directed to a transducer for a surface acoustic wave device adapted for coupling to an electrical load and/or source. A pair of interdigitated comb electrodes are formed on an acoustic wave propagating substrate, for example a piezoelectric substrate. Means, such as input or output terminals, are provided for applying an electrical load and/or source across the pair of comb electrodes. Each of the comb electrodes has a plurality of interdigitated electrode fingers. The width of at least some of the adjacent fingers of the electrodes are different and are selected as a function of the impedance of the load and/or source to produce mechanical electrical loaded (MEL) reflections in said substrate which tend to cancel regeneration wave (RW) reflections generated at the transducer in the substrate. In the preferred embodiment of the invention, each of the comb electrodes has at least two adjacent electrode fingers of different widths, and preferably has a plurality of adjacent finger pairs of different widths.
摘要:
A thermal transfer printer which can use both an ink sheet provided with a positioning mark to indicate the top position of a set of three color ink patches necessary for producing one image, and an ink sheet provided with no such positioning mark, without the need of switching an operation mode. The thermal transfer printer has an optical sensor which can equally detect a color change between 3rd and 1st color patches on the ink sheet provided with no positioning mark and a color change between a positioning mark and a 1st color patch on the ink sheet provided with the positioning mark. There is also disclosed an ink sheet cassette for use in the thermal transfer printer, the ink sheet cassette accommodating the ink sheet in which a positioning mark is coated with the same color(s) of ink as those for printing and information about the color sequence of the ink coated patches for printing is also recorded in the coated pattern of the positioning mark.