Abstract: An image display system includes semiconductor light sources that output optical signals including modulated signal portions at timings different from each other, optical fiber cables that respectively transmit the optical signals, a light synthesizer that synthesizes the optical signals to output a synthesized optical signal, a light amount detector that detects an output light amount of the synthesized optical signal, a modulated signal detector that detects the modulated signal portions from the detected output light amount, an image modulator that modulates the synthesized optical signal according to an input image signal to output a modulated image light, and a light source controller that outputs drive control signals for respectively outputting the optical signals respectively including the modulated signal portions according to the image signal, and detects a failure of the optical fiber cables based on whether a modulated signal portion among the plurality of modulated signal portions is detected.

Abstract: An optical member driving device includes an optical member that light is incident on; and a plurality of actuators that shift different portions of an outer peripheral edge of the optical member in a traveling direction of the light immediately before the light is incidence. Each of the plurality of actuators includes an arm that rotates about a rotation center line extending in a direction perpendicular to the traveling direction and supports the optical member at a first end of the arm, a conductor that is provided at a second end of the arm and extends in a direction from the second end toward the first end, the conductor being where a current flows, and a magnet pair that is provided to sandwich the second end of the arm at an interval and generates a magnetic field in a direction intersecting with a direction where the conductor extends.

Abstract: A semiconductor light source driving device includes: a switching power supply circuit that converts a voltage across direct current (DC) power supply into a DC output voltage and outputs the DC output voltage to a semiconductor light source; and a light source driving circuit connected in series to the semiconductor light source. The switching power supply circuit includes: a switching circuit; an output capacitor; a controller; and an inductor short circuit. The switching circuit includes: a first switching element for voltage control; a second switching element connected in series to the first switching element; and an inductor connected to a connection point between the first and second switching elements. The inductor short circuit includes a diode and a fourth switching element connected in series to the diode.

Abstract: A semiconductor light source driving device includes: a switching power supply circuit that converts a voltage across direct current (DC) power supply into a DC output voltage and outputs the DC output voltage to a semiconductor light source; and a light source driving circuit connected in series to the semiconductor light source. The switching power supply circuit includes: a switching circuit; an output capacitor; a controller; and an inductor short circuit. The switching circuit includes: a first switching element for voltage control; a second switching element connected in series to the first switching element; and an inductor connected to a connection point between the first and second switching elements. The inductor short circuit includes a diode and a fourth switching element connected in series to the diode.

Abstract: A projector light source modulation apparatus is provided, which includes a semiconductor laser driver circuit, that drives a semiconductor laser according to a second control signal generated based on a timing signal and a communication modulation code; a wavelength converter element, that converts a wavelength of output light from a semiconductor laser, and outputs a converted light; a light modulator element, that modulates the light outputted from the wavelength converter element according to a first control signal, and outputs a modulated light; and a projection lens that projects the modulated light from the light modulator element. Subframes are provided multiple times and arranged temporally at equal intervals for one interval of the vertical synchronization signal, each of the subframes turning on the light modulator element continuously for a superimposition interval of superimposing the communication modulation signal.

Abstract: An actuator driving device includes: first and second half bridge circuits driven according to modulated drive signals having an inverted relationship, generates a drive voltage for an actuator by switching a DC voltage, and outputs the drive voltage to the actuator; a current detection resistor which generates a current detection signal corresponding to current flowing through a series circuit including first and second switching elements and a series circuit including third and fourth switching elements; a hold circuit which holds the current detection signal from the current detection resistor and generates an output signal; a comparator which compares the output signal with a target amplitude signal to generate a comparison result signal; a multiplier which multiplies the comparison result signal and the drive signal to generate a multiplication result signal; and a PWM modulator which performs PWM modulation according to the multiplication result signal to generate a modulated drive signal.

Abstract: A semiconductor light-emitting device driving apparatus is disclosed with a semiconductor light-emitting device. In the semiconductor light-emitting device driving apparatus, a switching power supply outputs a driving current for driving the semiconductor light-emitting device, and a switching element controls the driving current to be turned on and off. A PWM modulator generates a PWM modulation signal for controlling the switching element to be turned on and off based on a PWM setting value inputted from outside, and a feedback circuit drives and controls the switching power supply based on the driving current and a target current value that is externally inputted. The feedback circuit drives and controls the switching power supply such that an average value of the driving current for an interval when the driving current flows is equal to the target current value.

Abstract: An actuator driving device includes: first and second half bridge circuits driven according to modulated drive signals having an inverted relationship, generates a drive voltage for an actuator by switching a DC voltage, and outputs the drive voltage to the actuator; a current detection resistor which generates a current detection signal corresponding to current flowing through a series circuit including first and second switching elements and a series circuit including third and fourth switching elements; a hold circuit which holds the current detection signal from the current detection resistor and generates an output signal; a comparator which compares the output signal with a target amplitude signal to generate a comparison result signal; a multiplier which multiplies the comparison result signal and the drive signal to generate a multiplication result signal; and a PWM modulator which performs PWM modulation according to the multiplication result signal to generate a modulated drive signal.

Abstract: A semiconductor light-emitting device driving apparatus is disclosed with a semiconductor light-emitting device. In the semiconductor light-emitting device driving apparatus, a switching power supply outputs a driving current for driving the semiconductor light-emitting device, and a switching element controls the driving current to be turned on and off. A PWM modulator generates a PWM modulation signal for controlling the switching element to be turned on and off based on a PWM setting value inputted from outside, and a feedback circuit drives and controls the switching power supply based on the driving current and a target current value that is externally inputted. The feedback circuit drives and controls the switching power supply such that an average value of the driving current for an interval when the driving current flows is equal to the target current value.

Abstract: A driving device includes: a driving circuit operating with a single power supply in accordance with a driving signal; a first parallel circuit formed of a first capacitor and a first zener diode connected together in parallel, and having a first end connected to an output terminal of the driving circuit; a series circuit connected between a second end of the first parallel circuit and a ground of the driving circuit, and formed of a diode and a second parallel circuit (of a second capacitor and a second zener diode) connected to each other in series; and a resistor is connected between the second end of the first parallel circuit and the ground of the driving circuit. A voltage across the resistor is used as an output voltage for driving the insulated gate semiconductor element. A voltage across the first capacitor is superimposed negative-wise on the output voltage.

Abstract: A light source modulation circuit includes a pulse width modulator (PWM) PWM-modulating an input PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal, a frequency divider circuit frequency-dividing the PWM carrier signal at a predetermined frequency division ratio to output a communication carrier signal, a communication modulator modulating the communication carrier signal according to an input communication modulation code to output a communication modulation signal, an operational circuit performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal, and a light source drive circuit generating a light source drive signal based on the light source modulation signal.

Abstract: An optical member driving apparatus includes an optical member for changing an optical path, a plurality of actuators each having a movable member which is controlled to move in one direction, a plurality of connecting members which connect edge portions of the optical member positioned on two axes orthogonal to each other and the movable members of the plurality of actuators, respectively, a position detector for detecting a moving amount of the movable member of each actuator and outputting a detection signal indicating the moving amount, and a controller for controlling movement of the movable member of each actuator based on the detection signal from the position detector so as to keep an intersection point of the two axes at constant position.

Abstract: A light source modulation circuit includes a pulse width modulator (PWM) PWM-modulating an input PWM carrier signal according to an input on-time ratio signal to output a PWM-modulated signal, a frequency divider circuit frequency-dividing the PWM carrier signal at a predetermined frequency division ratio to output a communication carrier signal, a communication modulator modulating the communication carrier signal according to an input communication modulation code to output a communication modulation signal, an operational circuit performing a logical AND operation of the PWM-modulated signal and the communication modulation signal to output a resulting signal of the operation as a light source modulation signal, and a light source drive circuit generating a light source drive signal based on the light source modulation signal.

Abstract: The projection image display apparatus includes a display element that emits image light generated by modulating light from a light source based, a pixel-shifter that shifts a pixel of a projected image by changing an optical path of the image light, a resampling circuit, a motion-interpolation image processing circuit, and a pixel-shift controller. The resampling circuit generates a plurality of sub-frame image signals having a resolution of the display element, by resampling an image signal having a resolution of the projected image. The motion-interpolation image processing circuit provides a motion-interpolation image process to the sub-frame image signals. The pixel-shift controller receives the sub-frame image signals having undergone the motion-interpolation image process.

Abstract: A drive control device for a motor includes an input terminal, an output terminal, an inverter circuit, a first switch unit, a capacitor, a diode, a rectifier circuit, a photo coupler, a second switch unit, and a voltage detector. The inverter circuit converts a direct current voltage into an alternating current voltage, and outputs the alternating current voltage to the output terminal. The first switch unit shorts the output terminal based on a control signal. The capacitor is connected to the input terminal, and is charged by a direct current voltage. The diode is connected between the input terminal and the capacitor. The diode limits a direction where a charge current for charging the capacitor flows. The rectifier circuit rectifies an induced voltage, which is generated in the motor, and outputs a rectified voltage. The photo coupler converts the rectified voltage into an optical signal, and thereafter, converts the optical signal into a converted signal.

Abstract: A driving device includes: a driving circuit operating with a single power supply in accordance with a driving signal; a first parallel circuit formed of a first capacitor and a first zener diode connected together in parallel, and having a first end connected to an output terminal of the driving circuit; a series circuit connected between a second end of the first parallel circuit and a ground of the driving circuit, and formed of a diode and a second parallel circuit (of a second capacitor and a second zener diode) connected to each other in series; and a resistor is connected between the second end of the first parallel circuit and the ground of the driving circuit. A voltage across the resistor is used as an output voltage for driving the insulated gate semiconductor element. A voltage across the first capacitor is superimposed negative-wise on the output voltage.

Abstract: A drive control device for a motor includes an input terminal, an output terminal, an inverter circuit, a first switch unit, a capacitor, a diode, a rectifier circuit, a photo coupler, a second switch unit, and a voltage detector. The inverter circuit converts a direct current voltage into an alternating current voltage, and outputs the alternating current voltage to the output terminal. The first switch unit shorts the output terminal based on a control signal. The capacitor is connected to the input terminal, and is charged by a direct current voltage. The diode is connected between the input terminal and the capacitor. The diode limits a direction where a charge current for charging the capacitor flows. The rectifier circuit rectifies an induced voltage, which is generated in the motor, and outputs a rectified voltage. The photo coupler converts the rectified voltage into an optical signal, and thereafter, converts the optical signal into a converted signal.

Abstract: The optical path changing device of the present disclosure includes an optical member having a parallel plate face for changing an optical path, and first, second, and third actuators. The first, the second, and the third actuators are connected with the optical member at first, second, and third vertices of a triangle imaginarily drawn on a plane parallel to the parallel plate face of the optical member. The first, the second, and the third actuators drive the optical member forward and backward in a normal direction of the parallel plate face at the first, the second, and the third vertices serving as points of load. The optical member has a center of gravity within the triangle when seen from the normal direction.

Abstract: The semiconductor light source drive device according to the present disclosure includes: a switching power source that is connected in series with a semiconductor light source element and a constant current circuit to output a predetermined voltage to the semiconductor light source element and the constant current circuit; a detection circuit that detects a voltage at a connecting point between the semiconductor light source element and the constant current circuit; and a controller that controls the voltage output from the switching power source based on the voltage detected by the detection circuit, and controls a current value of the constant current circuit based on a switching signal. The controller, prior to varying the current value of the constant current circuit, varies the voltage output from the switching power source in accordance with an amount to be varied in the current value of the constant current circuit.

Abstract: Prior to a rising timing of a switching signal, a second FET is turned ON for a predetermined period according to a voltage switching signal. This allows a sum of a supply voltage of a first switching power source and a supply voltage of a second switching power source to be applied to a series circuit of a semiconductor light source, a drain-source of a first FET, and a current detecting resistor for a predetermined period before and after the rising timing of the switching signal.