摘要:
A discharge lamp lighting device having a discharge lamp which has a pair of tungsten-made electrodes each having a protrusion formed at the tip thereof and an electric power feeding device which feeds an alternate current electric power to the discharge lamp, and is characterized in that the power feeding device has a function of switching between a first lighting mode in which a rated electric power is fed to the discharge lamp and a second lighting mode in which a lower electric power than the rated electric power is fed to the discharge lamp to light the discharge lamp, and therefore, can control electric power to be fed to the discharge lamp under such conditions that the average electric power change rate becomes 0.01-2.1 W/s during a mode switching period in which the switching from the first lighting mode into the second lighting mode is carried out.
摘要:
A discharge lamp lighting device having a discharge lamp which has a pair of tungsten-made electrodes each having a protrusion formed at the tip thereof and an electric power feeding device which feeds an alternate current electric power to the discharge lamp, and is characterized in that the power feeding device has a function of switching between a first lighting mode in which a rated electric power is fed to the discharge lamp and a second lighting mode in which a lower electric power than the rated electric power is fed to the discharge lamp to light the discharge lamp, and therefore, can control electric power to be fed to the discharge lamp under such conditions that the average electric power change rate becomes 0.01-2.1 W/s during a mode switching period in which the switching from the first lighting mode into the second lighting mode is carried out.
摘要:
A system for playing back information recorded on a recording disc includes a first servo control system responsive to a tracking error signal, which adjusts the position of an information reading point of a pickup relative to the recording track on the recording disc, and a second servo control system responsive to a synchronizing signal contained in the playback information signal, which adjusts the speed of rotation of the recording disc. The system is further provided with first detection means responsive to the tracking error signal for detecting a condition where the information reading point has moved across a predetermined number of sections of recording track in a radial direction of the recording disc, and a second detection means responsive to the synchronization signal for detecting a condition where the synchronization signal is not read out up to a predetermined number regularly, and a control means for suspending the servo control operation of at least one of the first and second servo control systems in accordance with output signals of the first and second detection means.
摘要:
An automatic disc player including a housing, disc carrier means to convey a disc between predetermined playback position and a predetermined withdrawal position ready to be withdrawn out of the housing upon termination of playback operation, signal generating means for producing control signals to be predominant over various steps of the playback operation, and an electric control circuit responsive to the control signals to control the various steps of the playback operation, the signal generating means comprising position detecting means responsive to movement of the disc to the withdrawal position and operative to produce a signal when the disc being moved away from the playback position reaches the withdrawal position, and playback re-start switch means which is operative to produce a signal in response to slight movement of the disc from the withdrawal position toward the playback position, the control signals to be produced by the signal generating means including signals to control the start of playback operation. The position detecting means and the playback re-start switch means are connected in series with between ground and the control circuit, and the signals to control the start of playback operation include the signal from the playback re-start switch means.
摘要:
A low pressure discharge lamp in which, even during uninterrupted operation, a low lamp voltage characteristic is maintained over a long time interval and in which high radiant efficiency can be obtained over a long time is achieved via a low pressure discharge lamp which has a tubular glass bulb in which a pair of electrodes are located opposite one another, by an electron emission material which contains lithium being included on or in the electrode substrate. Advantageously, the electron emission material contains at least one of the following materials: metallic lithium, an alloy of lithium and another metal, an oxide of lithium, a mixture of an oxide of lithium with another metal oxide, and an oxide which contains lithium and another metal element and which is a compound identified by the formula Li--M--O.sub.x where M designates at least one element selected from among the alkali earth metals, rare earth metals and transition metal, and x is the number of oxygen atoms required for valency equalization.
摘要:
Tracking servo control system for an information read-out system such as a video disc player system or a compact disc player system, comprises a servo loop switch for opening and closing the tracking servo loop, and a timing control circuit for generating a timing signal for controlling the servo loop switch in accordance with an on-track signal generated from a pickup output signal and zero cross timings of the tracking error signal. In order to control the operation of the servo loop switch, very accurately, a phase shift circuit is provided between a tracking signal generating means and a zero cross detection means, which has substantially the same phase characteristics as that of an equalizer circuit utilized in the tracking servo loop.
摘要:
An automatic disc player including a housing, disc carrier means to convey a disc between predetermined playback position and a predetermined withdrawal position ready to be withdrawn out of the housing upon termination of plaback operation, signal generating means for producing control signals to be predominant over various steps of the playback operation, and an electric control circuit responsive to the control signals to control the various steps of the playback operation, the signal generating means comprising position detecting means responsive to movement of the disc to the withdrawal position and operative to produce a signal when the disc being moved away from the playback position reaches the withdrawal position, and playback re-start switch means which is operative to produce a signal in response to slight movement of the disc from the withdrawal position toward the playback position, the control signals to be produced by the signal generating means including signals to control the start of playback operation. The position detecting means and the playback re-start switch means are connected in series with between ground and the control circuit, and the signals to control the start of playback operation include the signal from the playback re-start switch means.
摘要:
In a three-beam type optical data disk player, beam output disturbances due to an external disturbance such as vibration and the beam output disturbances due to a local defect on the disk are distinguished from each other, and the servo gain is adjusted according to whether the beam output disturbance is due to the external disturbance or due to the local defect, so that the main beam is controlled to correctly follow the track at all times.
摘要:
A cross-sectional area calculation section calculates a cross-sectional area of a subject as physical quantity with respect to a size of the subject, and an NEC calculation section calculates a noise equivalent count NEC as physical quantity for evaluating an image. The C-NEC calculation section calculates a noise equivalent count per unit area C-NEC as physical quantity for evaluating an image as per size of the subject in accordance with the cross-sectional area of the subject calculated in the cross-sectional area calculation section and the noise equivalent count NEC calculated in the NEC calculation section. Accordingly, the noise equivalent count per unit area C-NEC is calculated as noted above, whereby an index may be determined that is independent of the cross-sectional area of the subject in evaluating the image.
摘要:
A disc player comprising a signal pickup unit to read information from a disc on which program information including address information is recorded, the signal pickup unit being movable with respect to the disc, pickup drive means to drive the pickup unit for movement with respect to the disc, and a control circuit including an address memory for storing the newest one of the addresses read from the disc, a counter operative to count addresses at predetermined time intervals for producing a signal representative of an expected address indicative of the position to which the pickup unit is expected to move in the next, the expected address being updated at predetermined time intervals, a detector circuit to produce a signal each time a discrepancy is found to exist between the newest address and the expected address. In response to the signal from the detector circuit, the pickup drive means is actuated to drive the pickup unit for movement to the position dictated by the newest address or the expected address.