According to the present invention there is provided a projection device, which is configured to project an image which is co-operable with images projected by one or more other projection devices, wherein the projection device comprises a detector operable to detect characteristics of images projected on a display surface by the projection device and one or more other projection devices, and a controller operable to adjust the projection device and/or to adjust one or more of the other projection devices, based on the characteristics of the images detected by the detector, such that the images projected by each projection device co-operate on the display surfaces.

[Solving Means] A semiconductor light emitting element includes a first conductive layer, a second conductive layer, and an active layer provided between the first conductive layer and the second conductive layer. The first conductive layer has a current constriction structure, a current injection region being constricted in the current constriction structure. The active layer includes a plurality of quantum well layers, a first light emission wavelength being in a wavelength range of an intensity peak of an entire light emission spectrum, the first light emission wavelength corresponding to a light emission recombination level energy gap of a first quantum well layer of the plurality of quantum well layers, the first quantum well layer being provided at a position closest to the current constriction structure.

Apparatus and methods for displaying an image by a rotating structure are provided. The rotating structure can comprise blades of a fan. The fan can be a cooling fan for an electronics device such as an augmented reality display. In some embodiments, the rotating structure comprises light sources that emit light to generate the image. The light sources can comprises light-field emitters. In other embodiments, the rotating structure is illuminated by an external (e.g., non-rotating) light source.

Apparatus and methods for displaying an image by a rotating structure are provided. The rotating structure can comprise blades of a fan. The fan can be a cooling fan for an electronics device such as an augmented reality display. In some embodiments, the rotating structure comprises light sources that emit light to generate the image. The light sources can comprises light-field emitters. In other embodiments, the rotating structure is illuminated by an external (e.g., non-rotating) light source.

An image display device includes: a light source configured to change the amount of light, depending on a driving current; and a control unit configured to, when a change is made from a first gradation value to a second gradation value, control the driving current at the second gradation value, depending on a time period for which the first gradation value is set.

An image display device includes: a light source configured to change the amount of light, depending on a driving current; and a control unit configured to, when a change is made from a first gradation value to a second gradation value, control the driving current at the second gradation value, depending on a time period for which the first gradation value is set.

A scan display system includes a picture receiving unit, a scan needle, a picture display screen having first and second opposing surfaces, and a driving unit. The picture receiving unit is configured to receive picture data and transmits the picture data to the scan needle. The driving unit is configured to perform a picture scanning process by moving the scan needle to scan in a horizontal direction relative to the first of the picture display screen at a predetermined frequency. The scan needle is configured to emit light, representative of the picture data, to the first surface of the picture display screen to project image lines, each image line being formed by the scan needle during the scan. The picture display screen is configured to receive the emitted light on the first surface and display an image comprising the image lines on the second surface.

An image drawing device includes a laser light source controller controlling a laser light output timing of a laser light source unit and an output value of laser light so that a drawing image based on input image data is generated in a scanning region; a scanner controller controlling scanning so that the laser light is scanned with an amplitude; and a characteristic detection controller controlling the scanner controller to scan in a range in which an amplitude of scanning exceeds a scanning range corresponding to an amplitude when the laser light output value is adjusted, control the laser light source controller to output characteristic detection laser light during scanning outside of a range in which the drawing image is generated and beyond the amplitude of the scanning range, and adjust the output value of the laser light based on a detected output value of the characteristic detection laser light.

An image drawing device includes a laser light source controller controlling a laser light output timing of a laser light source unit and an output value of laser light so that a drawing image based on input image data is generated in a scanning region; a scanner controller controlling scanning so that the laser light is scanned with an amplitude; and a characteristic detection controller controlling the scanner controller to scan in a range in which an amplitude of scanning exceeds a scanning range corresponding to an amplitude when the laser light output value is adjusted, control the laser light source controller to output characteristic detection laser light during scanning outside of a range in which the drawing image is generated and beyond the amplitude of the scanning range, and adjust the output value of the laser light based on a detected output value of the characteristic detection laser light.

A scan display system includes a picture receiving unit, a scan needle, a picture display screen having first and second opposing surfaces, a projecting unit, and a driving unit. The picture receiving unit is configured to receive picture data and transmit the picture data to the scan needle. The scan needle is configured to emit light representative of the picture data. The projecting unit is configured to project the light emitted from the scan needle to the first surface of the picture display screen. The driving unit is configured to perform a picture scanning process to form a plurality of image lines. The picture display screen is configured to receive the projected light on the first surface and display an image comprising the image lines on the second surface.