Patent application number | Description | Published |
20090066278 | STEPPING MOTOR DRIVE AND STEPPING MOTOR DRIVING METHOD - In a drive of a stepping motor, an electromotive force is generated on the coil of a motor with a sinusoidal wave having the same period as an energization period by smoothly rotating a rotor with microstep driving, and an induced power is stably detected by detecting the electromotive force at the zero cross of driving current. The detection around the current zero cross makes it possible to shorten a detection section, form a driving waveform with few distortions, and perform driving with a driving waveform as in an ordinary micro step. Thus a circuit is provided which is aimed at reducing noise, vibrations, and loss of synchronization, and increasing current consumption efficiency in the determination of stop. | 03-12-2009 |
20100156861 | DISPLAY DRIVER AND DISPLAY APPARATUS - A display driver includes a shift register; an OR circuit configured to perform an OR operation on data signals respectively representing bits in the shift register which are not adjacent to each other, and to output a result of the OR operation; a delay circuit configured to delay the output of the OR circuit, and to output the delayed output; timing generators respectively corresponding to the data signals, where each of the timing generators generates and outputs a first control signal including a first pulse and a second control signal including a second pulse in accordance with a corresponding one of the data signals and the output of the delay circuit; and output circuits respectively corresponding to the timing generators, where each of the output circuits outputs voltages of a first and a second power supply. A duration of the second pulse includes a duration of the first pulse. | 06-24-2010 |
20110181341 | PUSH-PULL DRIVER CIRCUIT - A push-pull driver circuit includes a control circuit which controls switching operations of a plurality of high-side transistors, a level-shift circuit which shifts a control signal, output by the control circuit when the control circuit performs turn-off control on the plurality of transistors, to a first voltage by which the plurality of transistors are turned off, and which inputs the shifted signal to a gate of one of the plurality of transistors, and a conduction-state selection circuit which, if an output of the level-shift circuit is the first voltage, inputs the output to gates of the rest of the transistors, and otherwise, according to the control by the control circuit, sets each of gate inputs of the rest of the transistors to either a high-impedance state or a second voltage by which the plurality of transistors are turned on. | 07-28-2011 |
20110254823 | DRIVE DEVICE AND DISPLAY DEVICE - The drive device includes a first switch section including switching elements, a second switch section including switching elements, and output circuits. Each of the output circuits includes a switching element having a first and a second end, a first voltage being supplied to the first end, and a first and a second rectifier element each having a current input terminal and a current output terminal connected to the second end of the switching element. Each of the output circuits corresponds to one of the switching elements of the first switch section and one of the switching elements of the second switch section, the one of the switching elements of the first switch section is connected to the current input terminal of the first rectifier element, and the one of the switching elements of the second switch section is connected to the current input terminal of the second rectifier element. | 10-20-2011 |
20120056574 | Stepping motor driver - In a drive of a stepping motor, an electromotive force is generated on the coil of a motor with a sinusoidal wave having the same period as an energization period by smoothly rotating a rotor with microstep driving, and an induced power is stably detected by detecting the electromotive force at the zero cross of driving current. The detection around the current zero cross makes it possible to shorten a detection section, form a driving waveform with few distortions, and perform driving with a driving waveform as in an ordinary micro step. Thus a circuit is provided which is aimed at reducing noise, vibrations, and loss of synchronization, and increasing current consumption efficiency in the determination of stop. | 03-08-2012 |
20120104985 | STEPPING MOTOR DRIVE UNIT - In a stepping motor drive unit which drives a stepping motor including coils having a plurality of phases, and has functions of causing both ends of one of the coils having one of the plurality of phases to have high impedance to detect an inductive voltage in the coil, and determining a rotation/stop state of the stepping motor based on a result of the detection, the stepping motor drive unit has a function of temporarily stopping, while causing the both ends of the coil having the one of the plurality of phases to have high impedance, PWM driving of at least one of the other coils to fix an energized state of the coil. | 05-03-2012 |
20130114782 | DISPLAY PANEL DRIVE DEVICE - A display panel drive device includes: a ring counter circuit that includes a first ring counter having a plurality of flipflops connected in cascade, configured to operate in synchronization with a first clock signal with a first-stage one of the plurality of flipflops being set by an initial signal, and outputs signals using outputs of the plurality of flipflops; a shift register having a plurality of flipflops connected in cascade, configured to operate in synchronization with a second clock signal lower in frequency than the first clock signal with a first-stage one of the plurality of flipflops being set by the initial signal; and an output section configured to perform a logical operation between one of outputs of the ring counter circuit and one of outputs of the shift register, to generate a scanning line drive signal for a display panel. | 05-09-2013 |
20130147278 | INDUCTION LOAD DRIVING SYSTEM - When a direction command signal indicates a first direction, a signal for causing the other end of the induction load to be connected to a second power supply unit is output as a second control signal. In addition, after a passage of a first predetermined delay time after a first current detection value becomes less than a reference value of a conducting current, a signal for causing the one end of the induction load 5 to be connected to a first power supply unit is output as a first control signal. And, after a passage of a second predetermined delay time after the first current detection value becomes equal to or greater than the reference value of the conducting current, a signal for causing the one end of the induction load to be connected to the second power supply unit is output as the first control signal. | 06-13-2013 |
20140252950 | SEMICONDUCTOR LIGHT SOURCE LIGHTING CIRCUIT AND VEHICULAR LAMP - A semiconductor light source lighting circuit includes a voltage step-down unit configured to generate a drive voltage lower than an input voltage by turning on or off a first switching element in a voltage step-down mode, a voltage step-up unit configured to generate the drive voltage higher than the input voltage by turning on or off a second switching element in a voltage step-up mode, and a controller. The controller includes a charge pump unit configured to repeat charging from the drive voltage to a second capacitor and discharging from the charged second capacitor to the first capacitor in the voltage step-up mode, and a switch drive unit configured to apply a voltage higher than the voltage at the other end of the first switching element to the control terminal of the first switching element by using a voltage of the charged first capacitor. | 09-11-2014 |