Abstract: A digital servo system is provided for controlling a cylinder motor in a video tape recorder. The servo system includes a servo loop and a digital filter inserted in the servo loop. The digital filter includes a coefficient multiplying circuit for multiplying a coefficient. A coefficient changing circuit is further provided for changing the coefficient of the coefficient multiplying circuit. The digital filter is provided to improve the servo gain at a low frequency region. This avoids lag caused by the filter in this region, and advantageously provides resistance to disturbances.

Abstract: A motor servo system includes a microcomputer which obtains FG period data in response to an FG signal outputted from a capstan motor, and calculates rotation unevenness associate data D1 by totalizing (a hundred) absolute values of differences between each of respective FG period data and theoretical values. The microcomputer adjusts a gain of a servo circuit by comparing the rotation unevenness associate data D2 calculated at the last time and the rotation unevenness associate data D1 calculated at this time. That is, if D1>D2, a corrective gain .DELTA.G is inverted and stored into a memory as data D3. A new gain is determined by adding the data D3 and a present gain G.

Abstract: A remote control apparatus includes a television monitor capable of displaying an image according to a video signal sent from a camcorder through a video signal line. An operating portion of the remote control apparatus includes keys, and a microcomputer which generates a control signal according to a key input from the keys. The control signal is applied to an infrared ray emitting device when the apparatus is not connected to the camcorder such that the camcorder can be wireless-controlled. If the apparatus is connected to the camcorder through a control signal line and the video signal line, the control signal is applied to the camcorder through the control signal line, and a control signal for controlling a rotation table of the camcorder is applied to the infrared ray emitting device, and therefore, the camcorder can be wire-controlled and the rotation table can be wireless-controlled.

Abstract: A motor control system includes a microcomputer for executing a so-called software servo-control, and the microcomputer receives a speed signal and a phase signal from the motor. In the microcomputer, speed error data is evaluated on the basis of the speed signal, and speed integration data is evaluated on the basis of the speed error data and a first reference signal, and phase integration data is evaluated on the basis of the phase signal and a second reference signal. The speed error data, the speed integration data and the phase integration data is synthesized, so as to obtain motor control data.

Abstract: A motor servo system for controlling a motor includes a first synthesizing portion which synthesizes a speed detection signal and a phase detection signal with each other to produce a synthesized signal which is in turn filtered by a low-pass filter portion and then becomes a first motor control signal. The first motor control signal is applied to an equivalent motor portion (software motor) which is included in an observer and has a transfer function of as the same as that of the motor. A detection signal which is detected by the equivalent motor portion and a synthesized signal from the synthesizing portion are compared with each other by a first comparing portion. An output signal of the first comparing portion is applied to a second comparing portion or a second synthesizing portion.

Abstract: A microcomputer 1 servo controls a rotational speed of a capstan motor 10 in a VTR in a digital manner. A value of a timer counter 6 is stored in an ICR 7 at a timing of each edge of FG signal pulses generated as the capstan motor rotates. Thereafter, in the microcomputer 1, a FG interrupt processing is carried out corresponding to the value of ICR 7. More specifically, the microcomputer 1 alternately measures a first period from a rise of one pulse of the FG signal to a rise of a subsequent pulse thereof and a second period from a fall of one pulse to a fall of a subsequent pulse to determine an amplitude of a speed error signal based on these periods. Therefore, a sampling frequency for the digital servo control can be double that of a prior art.

Abstract: A microcomputer (20) servo controls the rotational speed and the rotational phase of a cylinder motor (37) of a VTR in a digital manner. The microcomputer (20) generates a 10-bit digital phase error signal D.sub.PH having sufficiently low conversion gain and a 10-bit digital speed error signal D.sub.SP having sufficiently low conversion gain in response to an FG signal generated with rotation of a cylinder motor. The digital phase error signal D.sub.PH and the digital speed error signal D.sub.SP are added to each other in a digital manner in the addition ratio 1:8. In addition, the result of this addition is amplified four times in a digital manner by extracting eight lower order bits thereof and then converted into an analogue signal and supplied to the cylinder motor as a servo control signal. Thus, since the error signals are added to each other in a digital manner and then, the added signal is amplified as required, a digital servo having a large capture range can be achieved as whole.

Abstract: A digital servo apparatus according to the present invention latches a count output of a counter (11) for counting reference clock signals in response to output of a speed detecting pulse from a speed detecting pulse generator (10a) in a latch circuit (141), thereby to latch the count output latched in the latch circuit (141) in another latch circuit (142) upon output of a subsequent speed detecting pulse. The digital servo apparatus further latches the count output of the counter (11) in a latch circuit (16) in response to output of a phase detecting pulse from a phase detecting pulse generator (10b). A comparator (15) compares difference between the count outputs latched in the latch circuits (141) and (142), so that the compared output difference and the count output latched in the latch circuit (16) are converted into analog signals to be sampled and held respectively thereby to produce a speed error signal and a phase error signal, which are added up to be supplied to a driving circuit (22).