摘要:
For improving the frequency characteristic of a color television signal, particularly one in which the chrominance component thereof is provided with a bandwidth substantially narrower than that of the luminance component, the luminance component is used to generate a control signal which is proportional to the lack of registration between low and high frequency portions of the luminance component spectrum, and the control signal thus obtained selectively increases and decreases a delay applied to the relatively narrow-bandwidth chrominance component to substantially align its excursions with the excursions of the relatively wide bandwidth luminance component.
摘要:
In a video signal reproducing apparatus having a cathode ray tube in which at least one electron beam is made to scan a screen in line-scanning and vertical directions while the intensity of the beam is modulated to establish the brightness of a video picture to be displayed on the screen, and in which bright picture portions are represented by respective high level portions of a video signal defined between rising and falling edges extending from low level signal portions representing contiguous dark picture portions; a waveshaping circuit receives the video signal and acts thereon to provide a compensated video signal in which the width of each high level portion between the respective rising and falling edges is increased, the compensated video signal is employed to control the intensity of the electron beam, the rising and falling edges of each high level portion of the video signal are detected to provide a beam velocity modulation signal with respective positive and negative peaks by which the scanning velocity of the beam in the line-scanning direction is modulated, and the positions of such positive and negative peaks are shafted, relative to the corresponding peaks of a differentiation of the video signal, in the directions toward the adjacent low level signal portions of the compensated video signal.
摘要:
In apparatus for reproducing color video signals recorded in successive parallel tracks on a record medium with the chrominance components of video signals recorded in next adjacent tracks having first and second carriers which differ from each other in respect to their phases or polarity characteristics; and in which a plurality of transducers scan along the tracks one at a time so as to reproduce the video signals recorded in each of said tracks along with cross-talk signals from the tracks next adjacent thereto, means for separating said chrominance signal components from the luminance signal component in the reproduced signals, and a signal processing circuit including a switching circuit and a comb filter provides the separated chrominance components of video signals reproduced from each of said tracks with a common carrier and eliminates therefrom the chrominance components of the cross-talk signals on the basis of said different phases of the first and second carriers with which the chrominance components were recorded in the tracks which are next adjacent to each other: the changing-over of the switching circuit is controlled in response to the phase of the chrominance component carrier that results therefrom so as to ensure phase alignment of the common carrier with which the chrominance components of the video signals reproduced from the successive tracks are provided. Further, control signals are recorded on the record medium to identify those tracks in which video signals are recorded with their chrominance components having said first and second carriers, respectively, and, on reproducing, such identifying control signals are reproduced to control the movements of the transducers and, through such controlled movements, to regulate the changing-over of the switching circuit.
摘要:
In reducing crosstalk between the low frequency, frequency-converted chrominance portions of h-aligned video signals on adjacent tracks, the frequency converting carrier, but not the entire frequency converted portion, has its polarity inverted at the end of each line interval during the recording of alternate tracks but not during the recording of the remaining alternate tracks. This eliminates the extraneous signal that would otherwise be produced in the balanced modulator of the playback apparatus by any direct voltage offset or transient remanent of a direct voltage offset in the recorded signal.
摘要:
A gain control circuit of the multistage differential amplifier type comprising a first pair of transistors forming a first differential amplifier supplied with an input signal, a second pair of transistors forming a second differential amplifier connected to amplify further the output of the first differential amplifier and a novel semiconductor device of the three-terminal type connected in common between the respective outputs of both the first pair of transistors and an operating voltage source, in which the gain control is attained by controlling the value of the current flowing through at least one differential amplifier. The novel semiconductor device has a semiconductive body similar to an ordinary transistor and acts as a bidirectionally conductive element with a superior symmetrical characteristic.
摘要:
A gain control circuit utilizing a novel bidirectional transistor connected in shunt with a pair of outputs of a differential amplifier circuit. The novel bidirectional semiconductor device has its conduction level controlled by a variable bias source in its base circuit. By adjusting the bias source, the impedance of the bidirectional device is controlled, and hence the magnitude of the output signal developed across its terminals is controlled in gain.
摘要:
A multipurpose switching circuit of the balanced type constituting a pair of switching paths each formed by first and second transistors connected in series and supplied with an input signal and a switching signal, respectively, and a novel semiconductor device of the three-terminal type with first and third terminals connected to both of the pair of switching paths, respectively, and a second terminal connected to an output terminal of the circuit. The respective second transistors of both the paths cause the switching operation to alternate in accordance with the switching signal, and both the input signals supplied to the respective first transistors of the pair of switching paths are alternately switched to the output terminal through the novel semiconductor device in response to the switching operation of the first transistors. The novel semiconductor device has a semiconductor body similar to an ordinary transistor and acts as a bidirectionally conductive element with superior symmetrical characteristics.
摘要:
A signal amplifying circuit including an amplifying transistor having its base-emitter terminals connected to a signal source. A diode having the proper characteristics is also connected across the base-emitter input terminals to produce a first reference bias voltage to be applied to the input circuit of the transistor. The emitter-collector circuit of a compensating transistor is connected in series with the emitter-collector circuit of the amplifying transistor, and a second reference bias voltage is connected between the base of the compensating transistor and the emitter of the amplifying transistor. The second reference bias voltage is produced across a plurality of diodes having the proper characteristics, whereby the current gain of the amplifier will be constant regardless of variations in the transistor characteristics.
摘要:
A multipurpose semiconductor circuit of the balanced type comprising a pair of differential signal transmitting paths, each of which is formed by a first transistor supplied with an input signal, a second transistor connected in series to the first transistor and supplied with a constant bias or a control signal, a load with an output terminal connected to the second transistor, and a novel semiconductor device of the three-terminal type with first and third terminals connected to connection points between first and second transistors of both signal transmitting paths, respectively. A second terminal of the novel semiconductor device is supplied with a control signal or a constant bias. The input signal is controlled in accordance with the control signal supplied to the novel semiconductor device or the second transistor and derived from the output terminal. The novel semiconductor device has a semiconductor body similar to an ordinary transistor and acts as a bidirectionally conductive element with a superior symmetric characteristic.
摘要:
An antenna apparatus has a first wire-like antenna element formed into a rectangular planar loop and a second antenna element which comprises two L-shaped plates electrically connected to the loop and mounted to a rectangular planar base member. The loop is hinged to the planar base member along long sides of the respective rectangles so that the angle between the planes of the loop and base member is adjustable. The base member pivots about an axis on a mount which can be secured to a television receiver.