A light transmitting device that includes a light transmitter that transmits a spatial light signal including a communication signal, and a light transmission control unit that adds a dummy signal having a same brightness as a ghost image of the communication signal to the spatial light signal and controls the light transmitter in such a way that the dummy signal is displayed at a position of the ghost image.

An object of the present invention is to provide a projection apparatus capable of appropriately performing control relating to a rotation state and/or a movement state of a projection lens. A projection apparatus according to an aspect of the present invention includes a housing; a light source; a control unit; and a projection lens attached to the housing, the projection lens having a holder, a detection unit that detects a rotation state of the holder, an emission optical system, and a locking mechanism unit that brings rotation of the holder into a locked state or an unlocked state. The projection lens is displaceable between a first position at which a rotation state of the holder is a housed state in which the emission optical system faces the housing and a second position at which the emission optical system does not face the housing by rotating the holder. The second position includes an upper position at which the emission optical system faces an upper side in a vertical direction. The control unit turns off the light source when a rotation state of the holder is the first position. The control unit turns on the light source when the rotation state of the holder is at the upper position. When the light source is turned on in the housed state in which the emission optical system faces the housing, the light emitted from the emission optical system hits the housing, and the temperatures of the projection lens and the housing may increase, which may cause an adverse effect. However, when the rotation state is the housed state, the control unit turns off the light source, thereby preventing the adverse effect.

The embodiments of the disclosure relates to the technical field of projection adjustment. Embodiments specifically disclose a self-adaptive adjustment method and adjustment system for brightness of a projection apparatus. In the disclosure, ambient illuminance and a projection distance of the projection apparatus are obtained by controlling an illuminance sensor and a distance sensor, and a functional relationship among the ambient illuminance, projection plane illuminance and the projection distance is found through analysis and modeling of a large amount of data.

A projector and a brightness adjusting method are provided. The projector includes a distance sensor configured to detect a distance between the projector and a projection plane, a light source configured to provide an illumination beam, a brightness controlling circuit configured to control the light source, and a processor coupled to the distance sensor, the light source, and the brightness controlling circuit. The processor calculates according to the distance to obtain an image size of a projected image on the projection plane. The processor obtains a current value corresponding to the image size according to a color table. The processor instructs the light source to adjust a luminous flux of the illumination beam according to the current value for generating a target brightness value of the projected image. When a brightness of the projected image is excessively large, a brightness of an image beam of the projector is automatically reduced.

Disclosed is a light source control apparatus, which includes an image acquirer that obtains information about an image to be displayed from a light source matrix, and a controller that changes a resolution of the image based on the information about the image and controls an operation of the light source matrix such that the image having the changed resolution is displayed.

A control system for a laser scanning projector includes a mirror controller generating horizontal and vertical mirror synchronization signals for an oscillating mirror apparatus based upon a mirror clock signal, and laser modulation circuitry. The laser modulation circuitry generates horizontal and vertical laser synchronization signals as a function of a received laser clock signal, and generates control signals for a laser that emits a laser beam that impinges on the oscillating mirror apparatus. Synchronization circuitry generates the laser clock signal and sends the laser clock signal to the laser modulation circuitry, receives the horizontal and vertical mirror synchronization signals from the mirror controller, receives the horizontal and vertical laser synchronization signals from the laser modulation circuitry, and modifies the laser clock signal so as to achieve alignment between the horizontal and vertical mirror synchronization signals and the horizontal and vertical laser synchronization signals.

A projection video display apparatus includes a video input unit, a light source, a display element, a projection optical system, and a variable light adjusting function which changes the amount of light incident on the display element. Display modes using the variable light adjusting function are prepared, and one display mode of the display modes can be selected from a menu screen. Further, the display modes of the display video using the variable light adjusting function includes: a first display mode where the input video is displayed while changing a light adjusting amount in accordance with light adjusting control information, which is input from external equipment and is capable of controlling the variable light adjusting function in unit of frame of a projected video; and a second display mode where the input video is displayed while changing a light adjusting amount in accordance with the input video.

A light source generating device, a projection apparatus and a light source generation method are provided. The light source generating device includes a first light source, an auxiliary light source, a control device, a driver and a current command generator. The first light source generates a first light beam. The auxiliary light source generates an auxiliary light beam corresponding to the first light beam. The control device generates a first driving signal to drive the first light source. The driver generates an auxiliary driving signal to drive the auxiliary light source according to the gate control signal and a current command. The current command generator receives an indication signal, and generates the current command according to the indication signal, wherein the indication signal corresponds to a driving current of the first light source. The invention has an effect of enhancing brightness/chrominance.

To provide a video projector which improves visibility in response to changes in projection environment, a video projector has an initial level setter, a level adjuster, a projection display, an image capture, and a projection histogram calculator. The initial level setter performs a prescribed initial level setting on an input video signal and outputs an initial display signal. The level adjuster adjusts the level of the initial display signal on the basis of a projection image and outputs a display signal. The image capture captures the projection image projected on a projection surface by the projection display based on the display signal. The projection histogram calculator prepares a projection histogram for each color. The level adjuster adjusts the level of the initial display signal for each color on the basis of the projection histogram.

Technologies pertaining to accounting for pulse history effects are described herein. In connection with accounting for pulse history effects, an amount of time between a first current pulse and a second current pulse that are to be transmitted to a pulsed laser is determined. Based upon such an amount of time, a determination is made as to whether a porch pulse is to be prepended to the second current pulse. When the porch pulse is to be prepended to the second current pulse, an amplitude and duration of the porch pulse are computed based upon the amount of time. The porch pulse is transmitted to the pulsed laser immediately followed by the second current pulse, wherein the porch pulse pre-charges the pulsed laser for emitting a pulse of light based upon the second current pulse.