Abstract: In a display unit which makes coherent light perform scanning on a screen to display an image, it is necessary to rotate a polygon mirror at ultrahigh speed for display of a high resolution image such as HDTV, and therefore, a high-performance polygon mirror must be employed, and further, noise and power consumption during rotation of the polygon mirror cause problems. Mirrors for multiple reflection (6a) and (6b) are inserted in a coherent light scanning optical system, whereby plural scanning lines can be obtained while one plane of the polygon mirror (5) scans one line of coherent light, leading to reduction in the rpm of the polygon mirror.

Abstract: The laser picture formation device includes a two-dimensional modulation element performing video image modulation as well as four or more laser light sources having different center wavelengths. The video images which have no speckle noises at the wavelength region that has high visibility, which are realized by simultaneously emitting the laser lights of green (G) and yellowish green (Y) which have particularly high visibility, and video images which are vivid as cannot be represented by the conventional display, and which can be realized by controlling the laser lights of respective colors independently, can be displayed. Particularly, by modulating the two-dimensional modulation element and the laser light output with synchronized with each other, various video displays are enabled.

Abstract: A two-dimensional image display device having a center wavelength of a red color source set in a range from 635 nm to 655 nm and having a center wavelength of a blue light source set in a range from 420 nm to 455 nm, to obtain a bright and clear image at minimum power consumption.

Abstract: A laser light source (10) has semiconductor lasers (1) and a waveguide tube (3) for propagating emission light from each of the semiconductor lasers (1). The semiconductor lasers are arranged on the upper end on the incident surface (31) side of the waveguide tube such that the emission light (4) from each of the semiconductor lasers enters into the waveguide tube from one end surface (31) of the waveguide tube and exits from the other end surface (32) of the waveguide tube. The structure can realize a small-sized laser light source having high output and capable of outputting emission light having uniform emission light intensity distribution.

Abstract: In a coherent light source in which limitations on the wavelength of emitted light are relaxed, a coherent light source for simultaneously emitting a first light (3) and a second light (4) having a wavelength shorter than that of the first light (3), includes: a light source main body emitting at least the first light (3); a mirror (5) which transmits or reflects the first light (3); and a functional film (6) provided on at least a part of the mirror (5). The functional film (6) has a photocatalytic effect to be induced by the second light (4).

Abstract: A laser image display device and a laser image display screen used for the laser image display device. The laser image display device is provided with a laser light source for emitting laser beams and a laser image display screen (10) for projecting the laser beams. The laser image display screen (10) is provided with a reflection scattering body (11) for scatter reflecting the laser beams, and a semi-transmissive diffusion layer (12) arranged substantially parallel to the reflection scattering body (11). The semi-transmissive diffusion layer (12) reflects at least a part of the laser beams, transmits the rest, diffuses the transmitting laser beams and projects them.

Abstract: An optical element (10) according to the present invention is provided with a plurality of waveguides (11)˜(13) and a plurality of light path coupling parts (21), (22) coupling adjacent waveguides so as to optically couple said plural waveguides serially, wherein the paths for transmitting lights through the plural waveguides are curved at the optical path coupling parts, thereby the optical elements which is converted the incident laser light into the emitted light having uniform cross-sectional light intensity distribution can give a compact structure, further a laser light source that employs the optical element, and a two-dimensional image forming apparatus that employs the laser light source can also give a compact structure.

Abstract: A display device (100) of the present invention has a first switch (3) and a second switch (4) on an upper surface of its casing, and includes a control circuit (18) for controlling the first switch (3) and the second switch (4) and a light source (19) inside the casing. The control circuit (18) performs control so that the light source (19) is turned on when the second switch (4) is pressed after a predetermined period of time has passed from when the first switch (3) was pressed. Thereby, the display device (100) of the present invention prevents entering of a person into a projection area before projection of video, and controls inadvertent start-up.

Abstract: A multiplexed holographic recording apparatus of the present invention records multiplexed holograms in a plurality of recording regions that are formed on a holographic recording medium. In particular, the apparatus first records a predetermined number of multiplexed holograms in each of the recording regions formed in a predetermined range or an overall range of the holographic recording medium through holographic recording performed N times, and then performs the (N+1)th holographic recording in each recording region formed in the predetermined range or the overall range. When n other recording regions (where n=0, 1, 2, . . . ) are superimposed on each recording region formed on the holographic recording medium, a difference in the degree of multiplexing between the recording regions formed in the predetermined range or the overall range of the holographic recording medium does not exceed a predetermined value of n+1.

Abstract: In a semiconductor laser device (10) having different facet reflectivities, an electrode disposed on a stripe ridge (107a) is divided into four electrode parts (1), (2), (3), and (4), and a larger injection current is injected to an electrode part that is closer to a light emission facet side. Further, a carrier density distribution in an active layer that is opposed to the stripe ridge can be matched to a light intensity distribution in the active layer, thereby preventing degradation in high output characteristic due to destabilization of a transverse mode and reduction in gain which are caused by spatial hole burning.

Abstract: An image display device and an image display system which can establish visible light communication without interfering with an image displayed at a predetermined frame rate are provided. A controller 12 controls a spatial light modulator in accordance with an image signal to display the image, and also modulates an intensity of a visible light output from a backlight 13 with a frequency higher than the frame rate of the image signal to have the visible light output from the backlight 13 carry additional information. A light receiver 15 receives the visible light and demodulates to extract the additional information. An additional information generator 16 outputs the additional information.

Abstract: In a laser picture formation device which forms a vide image by irradiating lights emitted from plural laser light sources (1a, 1b, 1c) which obtains monochromatic lights from laser lights which are outputted from the respective laser light emission parts to spatial light modulators (5a, 5b, 5c), each of the plural laser light sources (1a, 1b, 1c) detect the output of laser light which is emitted from the respective laser light emission parts on the basis of the modulation input signal which for modulating the spatial light modulator. Thereby, it is possible to confirm the deterioration situation of the respective laser light emission parts without deteriorating the video images which are projected onto the screen, as well as without separating the synthesized light respectively.

Abstract: A surface emitting laser (100a) includes an active layer (3) disposed on a semiconductor substrate (2a), and a pair of upper and lower electrodes (5,6) for injecting carriers into the active layer (3). The plane surface of the lower electrode (6) is shaped into a star so that injection of current into the active layer (3) from the lower electrode (6) is carried out with a high density at the center of the lower electrode (6) and with a low density at its periphery part. In the surface emitting laser (100a), the density distribution of the carriers injected into the active layer corresponds to the power distribution of light inside the active layer. Thereby, hole burning due to an increase in the current density in the region of the active layer corresponding to the peripheral part of the electrode is avoided, and the transverse mode stability during high output operation is significantly enhanced to improve high-output characteristic.

Abstract: There is provided a light source device which can miniaturize a two-dimensional image display device as small as possible. The light source device is provided with three coherent light sources (11a), (11b), and (11c) corresponding to red, blue, and green; prisms (12a) and (12c) for reflecting lights emitted from the coherent light sources (11a) and (11c); and a diffraction part (20) comprising a single volume hologram on which plural gratings are multiply-formed, which gratings diffract the light emitted from the coherent light source (11b), and the lights that are emitted from the coherent light sources (11a) and (11c) and reflected by the prisms (12a) and (12b) so that these lights propagate in the same optical path.

Abstract: A reflection-type laser projector (100) projects modulated laser beams outputted from a laser projection unit (40), on a screen, wherein a reflector (112) as a constituent of the screen (110) has reflection characteristics of reflecting, among the incident light, only laser beams of three colors of red, blue, and green, which are projected from the laser projection unit (40) and light in the neighboring wavelength band, and transmitting light in other wavelength bands, thereby preventing pictures on the screen (110) from becoming hard to be seen due to effects of indoor illumination or light from outdoors.

Abstract: An image projector realizing image projection with high image quality by reducing speckle noise. An image projector comprising a coherent light source, a collimation lens for transforming coherent light emitted from the coherent light source into coherent parallel light, and a projection optical system for projecting coherent parallel light is further provided with a reflection element for reflecting the coherent parallel light and capable of oscillating in parallel with the direction normal to the reflection plane, and a reflection element drive means for causing oscillatory motion of the reflection element.

Abstract: In a laser display that displays a video by scanning a beam from a laser light source two-dimensionally on a screen, the image quality being displayed is deteriorated markedly by speckle noises induced from coherency of the light source. A method for oscillating the screen to remove the speckles has problems that a large-scale device is necessary and the screen cannot be chosen without any restrain. A speckle pattern being generated is changed at a high speed by oscillating a light spot on the screen at a high speed using beam oscillation means 3, so that the viewer acknowledges time-mean image having no speckle noises.

Abstract: A light diffuser containing light diffusing elements is arranged in the most appropriate position between a spatial light modulator and an illumination optical system. Thereby, particles as light diffusing elements diffuse rays of light emitted from a laser light source. Accordingly, indefinite numbers of speckle pattern are formed so that, for example, a speckle noise which occurs on an image projected to a screen is reduced. As a result, loss of light amount after light diffusion is suppressed to small amount, and thereby a laser image display apparatus capable of displaying a bright and high-quality image having no luminosity irregularity is provided.

Abstract: A light source device for display device for projecting an image on a screen is provided, the light source device for display device including a light source unit operable to output light; an image outputting unit operable to output an image by giving an image signal to the light; and a control circuit operable to switch the image output from the image outputting unit between a normal image and a mirror reversed image formed by reversing the normal image right and left by controlling the image signal, such that outputting type is switched between a front projection in which the image is projected onto the screen from a front on the same side as the viewing side, and a rear projection in which the image is projected onto the screen from a rear plane on the opposite side to the viewing side.

Abstract: In a two-dimensional image display device, speckle noise is reduced by a simple construction. A two-dimensional image display device for displaying an image by projecting coherent light onto a projection plane is provided with at least one coherent light source (1a), (1b), (1c) for outputting coherent light, a polarization state modulator 6 for modulating at least one of a polarization state and a phase of the coherent light emitted from the coherent light source, and a birefringent diffusion plate (7) for spatially varying the phase of the coherent light emitted from the polarization state modulator. The polarization states of light spots in the respective pixels of the image displayed on the projection plane are spatially and temporally varied, thereby forming various speckle patterns.