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.

Abstract: A semiconductor light source driving apparatus of the present disclosure includes a switching power supply that supplies a DC voltage, a power source switching FET, a coil, an inverting FET driver, a semiconductor light source device, and a free-wheeling diode. The power source switching FET switches on/off an output of a positive terminal of the switching power supply in accordance with an input PWM signal. The coil has a first end connected to the output of the power source switching FET. The inverting FET driver is connected between a second end of the coil and a negative terminal of the switching power supply and switched on/off in accordance with an input signal. The semiconductor light source device is connected between the second end of the coil and the negative terminal of the switching power supply. The first end of the coil and the negative terminal of the switching power supply are connected to the free-wheeling diode.

Abstract: A semiconductor light source drive device includes a semiconductor light source; a switching element that controls a current flowing through the semiconductor light source by being on/off-controlled by a PWM signal provided to the control end; a current detection element that detects a current flowing through the semiconductor light source; a switching power source that supplies power supply voltage to a series connection of the semiconductor light source, the switching element, and the current detection element; a PWM supply circuit supplies the PWM signal and its on-time ratio information; a target value setting part converts the on-time ratio information to a target average current value and outputs the target average current value; and a comparator compares the target average current value with an average current value detected by the current detection element and outputs comparison output to the switching power source as a signal for control.

Abstract: The semiconductor light source driving apparatus includes light source modules, a current control element, a second current detection element, a DC power supply, and a controller. The light source modules each include the following components connected in parallel: a semiconductor light source; a first constant-voltage diode; a series circuit of a first current detection element and a second constant-voltage diode with a lower breakdown voltage than the first constant-voltage diode; and a switching element. The controller controls the DC power supply based on a detection output of the second current detection element. After the first current detection element generates a output in response to an open fault in any of the semiconductor light sources, and then the current control element is turned off, the controller turns on the switching element of the light source module with the open fault, thereby allowing the current control element to be controlled.

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.

Abstract: An optical member driving device of the present disclosure includes an optical member for changing an optical path, the optical member having a parallel flat plate shape; a driving mechanism having a movable portion controlled to move in a direction orthogonal to a surface of the optical member by a drive signal, the driving mechanisms being disposed outside the optical member; a connecting member rotatably connecting an end of the optical member and the movable portion of the driving mechanism on two axes orthogonal to each other at a surface center of the optical member; a support portion disposed between the end of the optical member and the movable portion of the driving mechanism, the support portion rotatably pivoting the connecting member; and a controller configured to control the movable portion of the driving mechanism.

Abstract: A semiconductor light source driving apparatus of the present disclosure includes a switching power supply that supplies a DC voltage, a power source switching FET, a coil, an inverting FET driver, a semiconductor light source device, and a free-wheeling diode. The power source switching FET switches on/off an output of a positive terminal of the switching power supply in accordance with an input PWM signal. The coil has a first end connected to the output of the power source switching FET. The inverting FET driver is connected between a second end of the coil and a negative terminal of the switching power supply and switched on/off in accordance with an input signal. The semiconductor light source device is connected between the second end of the coil and the negative terminal of the switching power supply. The first end of the coil and the negative terminal of the switching power supply are connected to the free-wheeling diode.

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: 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 driving apparatus includes light source modules, a current control element, a second current detection element, a DC power supply, and a controller. The light source modules each include the following components connected in parallel: a semiconductor light source; a first constant-voltage diode; a series circuit of a first current detection element and a second constant-voltage diode with a lower breakdown voltage than the first constant-voltage diode; and a switching element. The controller controls the DC power supply based on a detection output of the second current detection element. After the first current detection element generates a output in response to an open fault in any of the semiconductor light sources, and then the current control element is turned off, the controller turns on the switching element of the light source module with the open fault, thereby allowing the current control element to be controlled.

Abstract: The light sensitivity controlling apparatus comprises an optical semiconductor, an amplifier element, a resistor unit, an A/D converter, and a controller. The optical semiconductor receives a plurality of colors of light emitted from a light source in a time division. The amplifier element converts optical current flowing to the optical semiconductor into voltage by receiving the plurality of colors of light. The resistor unit switches the gain for converting the optical current inputted to the amplifier element into voltage, for each of the plurality of colors of light. The A/D converter converts the voltage outputted by the amplifier element from an analog signal into a digital signal. The sensitivity controlling apparatus controls the resistor unit so that the output level corresponding to the various colors of light outputted from the A/D converter will remain substantially same level.

Abstract: A semiconductor light source drive device includes a semiconductor light source; a switching element that controls a current flowing through the semiconductor light source by being on/off-controlled by a PWM signal provided to the control end; a current detection element that detects a current flowing through the semiconductor light source; a switching power source that supplies power supply voltage to a series connection of the semiconductor light source, the switching element, and the current detection element; a PWM supply circuit supplies the PWM signal and its on-time ratio information; a target value setting part converts the on-time ratio information to a target average current value and outputs the target average current value; and a comparator compares the target average current value with an average current value detected by the current detection element and outputs comparison output to the switching power source as a signal for control.

Abstract: A semiconductor light source driving apparatus includes a light source unit including plural light source modules connected in series, each light source module including a series circuit including one or more series-connected light source elements and a switching element connected in parallel with the series circuit, a current detection unit for detecting a current flowing into the light source unit, and a controller. The controller identifies a light source module including a light source element which has disconnection failure based on a signal from the current detection unit, and stores information indicating the identified light source module in the memory unit. The controller turns on the switching element of the light source module including the light source element having disconnection failure based on the information stored in the memory unit to solve the disconnection failure.

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 projection video display apparatus includes: a converter that converts an input video signal having a first number of pixels and a first frame rate into a conversion video signal having a second number of pixels and a second frame rate, the second number of pixels being smaller than the first number of pixels, and the second frame rate being an n-th multiple (n is an integer of 2 or greater) of the first frame rate; an optical element that displaces an optical axis of the video light beam; an optical element driving unit that drives the optical element at a frequency F being a natural-number multiple of the first frame rate; and a rotating body that rotates at a rotation speed R. The rotation speed R is set so as to become a value within a predetermined range corresponding to the frequency F.

Abstract: An optical member driving device of the present disclosure includes an optical member for changing an optical path, the optical member having a parallel flat plate shape; a driving mechanism having a movable portion controlled to move in a direction orthogonal to a surface of the optical member by a drive signal, the driving mechanisms being disposed outside the optical member; a connecting member rotatably connecting an end of the optical member and the movable portion of the driving mechanism on two axes orthogonal to each other at a surface center of the optical member; a support portion disposed between the end of the optical member and the movable portion of the driving mechanism, the support portion rotatably pivoting the connecting member; and a controller configured to control the movable portion of the driving mechanism.

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: A projection video display apparatus includes: a converter that converts an input video signal having a first number of pixels and a first frame rate into a conversion video signal having a second number of pixels and a second frame rate, the second number of pixels being smaller than the first number of pixels, and the second frame rate being an n-th multiple (n is an integer of 2 or greater) of the first frame rate; an optical element that displaces an optical axis of the video light beam; an optical element driving unit that drives the optical element at a frequency F being a natural-number multiple of the first frame rate; and a rotating body that rotates at a rotation speed R. The rotation speed R is set so as to become a value within a predetermined range corresponding to the frequency F.

Abstract: A semiconductor light source driving apparatus includes a light source unit including plural light source modules connected in series, each light source module including a series circuit including one or more series-connected light source elements and a switching element connected in parallel with the series circuit, a current detection unit for detecting a current flowing into the light source unit, and a controller. The controller identifies a light source module including a light source element which has disconnection failure based on a signal from the current detection unit, and stores information indicating the identified light source module in the memory unit. The controller turns on the switching element of the light source module including the light source element having disconnection failure based on the information stored in the memory unit to solve the disconnection failure.

Abstract: An image display device includes a plurality solid-state light sources, a modulator configured to modulate light from a plurality of solid-state light sources, and an image display device configured to generate from a frame of image data, a plurality of subframes each further divided into subfields, and to display the plurality of subframes. The modulator turns off light output from all the solid-state light sources for the duration of one or more of the plurality of subframes, whereby it is possible to reduce motion blur arising from a hold-type display device, in which after-images remain on the retina of a person's eyes when viewing moving objects.