摘要:
A scanning position of laser light applied to a projection plane is detected, and based on the detected scanning position, a synchronization signal is generated to designate a scan timing. A correction region detection portion detects whether or not a part corresponding to a prescribe region of an image on the projection plane is scanned by laser light, based on the generated synchronization signal. When the part corresponding to the prescribed region is scanned, a correction amount derivation portion corrects a gradation signal based on the difference between the detected quantity of laser light and a prescribed quantity of light to be output from the laser for displaying the image in the prescribed region.
摘要:
A scanning position of laser light applied to a projection plane is detected, and based on the detected scanning position, a synchronization signal is generated to designate a scan timing. A correction region detection portion detects whether or not a part corresponding to a prescribe region of an image on the projection plane is scanned by laser light, based on the generated synchronization signal. When the part corresponding to the prescribed region is scanned, a correction amount derivation portion corrects a gradation signal based on the difference between the detected quantity of laser light and a prescribed quantity of light to be output from the laser for displaying the image in the prescribed region.
摘要:
An image display apparatus wherein reduction in contrast or resolution is prevented is provided. A laser projector as an embodiment of the image display apparatus includes a memory storing a threshold value predetermined for changing a driving mode of a laser light source, a calculator for calculating an optical power level for projecting an image, a driving-mode selector selecting a mode for driving the laser light source, a driving controller for sending a signal to the laser light source in accordance with a selected driving mode, and a laser emitter. The laser projector operates at least at a bias current value Ib or more. In this case, when the optical power level is lower than or equal to a predetermined threshold value TH, the laser projector emits pulsed light. When the optical power level based on a video signal exceeds threshold value TH, the laser projector changes the driving mode of laser light emission from pulsed light emission to DC light emission, to supply a current higher than or equal to bias current value Ib to each laser light source.
摘要:
A projector divides and projects a single image onto two different projection surfaces and performs virtual user interface through one projection surface. The projector projects a VUI screen image on a desk and projects a main projected screen image on a wall. The projector includes a light receiving element, which is installed at a position that receives light emitted to the desk (the projection surface of the VUI screen image) and reflected (or scattered) by an object in the vicinity of the desk. The projector calculates a position of the object based on a light detection timing of the light-receiving element and a scanning position of light at each time and changes a projected image based on the calculated position. The projector displays a designated region of the VUI screen image to be brightened.
摘要:
A laser projector can generate a pulse signal capable of being generated according to the resolution of the clock signal, the pulse signal having a basic period and a basic pulse width each infinitely approximated to the characteristics of the resonance frequency. Moreover, because the laser projector can generate a pulse signal capable of correcting the errors led to be included in the approximated pulse signal, the laser projector can drive the scanning section with a horizontal vibration width corresponding to the resonance frequency, and can suitably display a projected image on a projection plane.
摘要:
Disclosed in a laser projector to display an image by projecting a laser beam from a laser light source to a projection screen including an electromagnetic driven scan mirror to scan the laser beam from the laser light source, a detection unit to detect a back EMF which is generated by a drive of the electromagnetic driven scan mirror at a time of start-up of the laser projector, a first determination unit to determine whether a value of the back EMF which is detected by the detection unit exceeded a predetermined threshold or not and a light source control unit to start a lighting of the laser light source when the value of the back EMF is determined as exceeding the predetermined threshold by the determination unit.
摘要:
When a position detector detects that the position of a spot on a projection plane designates a non-projection region, the level of a driving signal of a laser is corrected. Specifically, the correlation between the quantity of laser light detected by a light-receiving portion and the level of the driving signal of the laser in accordance with prescribed data is detected. Then, the characteristic value of the laser indicated by the detected correlation is compared with the characteristic value at room temperature stored beforehand to indicate the correlation between the quantity of light emitted by the laser at room temperature and the level of the driving signal. Then, based on the comparison result, the level of the driving signal of the laser in accordance with image data is corrected.
摘要:
A laser driver circuit comprising a current supply circuit for supplying a laser diode with a current is provided. The current supply circuit comprises a voltage-to-current converter circuit, a current output line for outputting the current generated by the voltage-to-current converter circuit, a current supply line connected to the laser diode, a ground line connected to the ground, and a current path switch for selectively connecting either the current supply line or the ground line to the current output line. The laser driver circuit further comprises a current output prevention circuit for preventing the voltage-to-current converter circuit from generating the current by disconnecting the voltage input line using a voltage input switch so that the voltage is not input to the voltage-to-current converter circuit, when the current output line and the ground line are connected by the current path switch.
摘要:
Disclosed in a laser projector to display an image by projecting a laser beam from a laser light source to a projection screen including an electromagnetic driven scan mirror to scan the laser beam from the laser light source, a detection unit to detect a back EMF which is generated by a drive of the electromagnetic driven scan mirror at a time of start-up of the laser projector, a first determination unit to determine whether a value of the back EMF which is detected by the detection unit exceeded a predetermined threshold or not and a light source control unit to start a lighting of the laser light source when the value of the back EMF is determined as exceeding the predetermined threshold by the determination unit.
摘要:
To prevent effectively the flickering of an image due to the switching of a polarization direction while reducing speckle noise. A polarization switching unit is provided in an optical path of laser light to a projection surface A and periodically switches a polarization direction of the laser light emitted therefrom between p and S polarization. A laser control unit controls laser light sources in synchronization with the switching by the polarization switching unit and determines a driving current corresponding to a grayscale to be displayed on the basis of driving current characteristics for P polarization when the polarization direction of the laser light is the P polarization. In addition, the laser control unit determines the driving current corresponding to the grayscale to be displayed on the basis of the driving current characteristics for P polarization when the polarization direction of the laser light is the S polarization.