Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Towerjazz Panasonic Semiconductor Co., Ltd.

Toshifumi Yokoyama

Kazuhisa Yamamoto

Kiminori Mizuuchi

Hiroyuki Furuya

Yasuo Kitaoka

Ken'ichi Kasazumi

Tetsuro Mizushima

Tatsuo Itoh

Kenji Nakayama

Akihiro Morikawa

Koichi Kusukame

Shin-ichi Kadowaki

Akira Kurozuka

Shinichi Kadowaki

Hiroshi Masuda

Tomoya Sugita

Nobuyuki Horikawa

Yoshiaki Nishi

Masakatsu Suzuki

A solid state imaging device has a global shutter structure and includes: a photodetector; a wiring layer; a first transparent insulating film disposed immediately above the photodetector and penetrating the wiring layer; a transparent protective film covering the wiring layer and the first transparent insulating film, and having a higher refractive index than the first transparent insulating film; a first projection provided on the transparent protective film and having a quadrilateral shape in top view; and a second transparent insulating film having a lower refractive index than the first projection.

Solid-state imaging device

A wavelength conversion laser light source includes: a fundamental light source for outputting fundamental light; a wavelength conversion element with a nonlinear optical effect for converting the fundamental light into harmonic light of a different wavelength; a first optical receiver for receiving light of a specific polarization direction contained in the fundamental light output from the fundamental light source and converting an amount of light thereof into an electrical signal; a second optical receiver for receiving the harmonic light output from the wavelength conversion element and converting an amount of light thereof into an electrical signal; a temperature holding unit for holding a temperature of the wavelength conversion element constant; a fundamental light control unit for performing first control of controlling an amount of light of the fundamental light output from the fundamental light source based on the electrical signal from the second optical receiver, and second control of controlling an amount of light of the fundamental light based on the electrical signal from the first optical receiver; and a temperature control unit for performing third control of controlling a holding temperature of the temperature holding unit based on the electrical signal from the second optical receiver.

Wavelength conversion laser light source having dual optical receiver and a temperature control unit, and projection display device, liquid crystal display device and laser light source provided with same

A 2D image display apparatus using a laser light source. By controlling the timing of a scan by a beam scan portion in response to the characteristic of a laser light source and by setting a light emitting time of the laser light source to an integral multiple of a scan cycle of the beam scan portion, it is possible to illuminate a spatial light modulator homogeneously with a laser beam. It is thus possible to display an image at high accuracy without causing a bright line, irregularities in brightness, and contrast deterioration.

Image display apparatus

A wavelength conversion laser is provided with a solid-state laser having a cavity, and a wavelength converting element arranged within the cavity. The solid-state laser includes two or more types of laser crystals and oscillates solid-state laser light of multiple wavelengths. The wavelength converting element converts the solid-state laser light of multiple wavelengths into light of second harmonic waves and sum-frequency wave of multiple wavelengths and simultaneously generates the second harmonic waves and sum-frequency wave of multiple wavelengths. The wavelength conversion laser outputs converted wavelength light having a broad spectral width and low coherency, thereby enabling it to carry out highly efficient and stable high-output oscillation.

Wavelength conversion laser

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

Display device

A semiconductor laser light source emits a laser beam for pumping. An optical resonator includes a solid laser crystal to be excited by the incident of a laser beam to oscillate a fundamental wave and a pair of fundamental wave reflective coats arranged at the opposite sides of the solid laser crystal. A wavelength conversion element converts the fundamental wave into a plurality of harmonics. The wavelength conversion element is so arranged in the optical resonator that the optical axis of at least one of the plurality of harmonics, generated in the optical resonator is made different from that of the fundamental wave and the at least one harmonic whose optical axis is made different is output substantially in the same direction as the other harmonic. By this construction, it is possible to stabilize a harmonic output and utilize a plurality of harmonics without increasing the number of parts.

Solid-state laser device and image display device

A light source device for a 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.

Light source device for display device, display device, and method for adjusting image of display device

According to the present invention, a laser light source comprises plural semiconductor lasers (), a solid laser (), a non-linear material () as a wavelength conversion element, a reflection coat () formed on one facet of the solid laser, and a reflection coat () formed on one facet of the non-linear material (), and the solid laser and the wavelength conversion element are disposed between the both reflection coats to constitute a laser resonator, and plural pump parts () in the solid laser () which are pumped by the plural semiconductor lasers are separated from each other by 300 &#x3bc;m or more. Thereby, interference between transverse modes of laser oscillation is avoided, thereby providing a high-power, stable, and compact solid laser light source with which a stable high output power can be obtained.

Laser light source and display device

In the video projector of the present invention, a fiber part of a fiber laser is disposed so as to draw a circulating orbit of more than one circulation along the inner wall of the projector housing. Further, an FBG which is part of the fiber laser is fixed so that its shape is not changed. Furthermore, a pump LD part of the fiber laser is disposed apart from the SHG element. As a result, the video projector can be miniaturized, and the portability and installment of the video projector are facilitated. Further, the output stabilization of the fiber laser can be realized by preventing a shape change of the FBG. Furthermore, by disposing the SHG element apart from the pump LD part which forms a heat source, the temperature change of the SHG element is suppressed and the wavelength conversion efficiency by the SHG element is enhanced.

Video projector using coherent light source

An internal resonator type SHG light source includes a pump light source which emits a pump light; a solid-state laser which absorbs the pump light and which emits a fundamental wave; an output mirror provided so as to face the solid-state laser, which forms a resonator together with the solid-state laser; a wavelength conversion element provided in the resonator, which converts the fundamental wave into a harmonic wave; a detector which detects a temperature of the wavelength conversion element; and a rotating unit which changes an incident angle of the fundamental wave on the wavelength conversion element by rotating the wavelength conversion element, wherein the rotating unit rotates the wavelength conversion element according to the temperature of the wavelength conversion element as detected by the detector.

Internal resonator type SHG light source

A display device of the present invention is provided with a light source () for emitting coherent light and displaying an image, and an image receiving part () comprising not less than two screens, onto which the coherent light is projected, wherein at least one of the screens constituting the image receiving part () is vibrated by an airflow applied to a front or rear surface of the image receiving part (). Further, the image receiving part () has a function of a speaker. Thereby, when coherent light is used as a light source for display, it is possible to suppress spots of light intensity which are called speckle noise and occur due to interference of laser beams reflected at the image receiving part.

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 () and () are inserted in a coherent light scanning optical system, whereby plural scanning lines can be obtained while one plane of the polygon mirror () scans one line of coherent light, leading to reduction in the rpm of the polygon mirror.

Display unit and scanning method therefor

Efficient coupling structures are important for the realization of reliable and economical integrated optical circuit applications. This paper presents a new approach for the simulation of an anisotropic plasma etching process in silicon based on a string point model as well as the realization and the results of etching processes in silicon, silicon dioxide, silicon oxinitride and silicon nitride which are fundamental for the fabrication of coupling structures. The connections to active and passive components were fabricated using plasma etching and deposition processes which are compatible with C-MOS or BIC-MOS technology. The realized waveguide-detector structures with vertical and horizontal silicon PIN-diodes exhibit efficiencies close to 90% for wavelength below 1.1 micrometers. The diodes can detect signals of modulation frequencies of more than 400 MHz due to horizontal light injection and capacitances less than 1 pF. Fiber-detector coupling structures with U-grooves for the fiber alignment containing such detectors show similar results. The necessary accuracy of the etched depth of the U-grooves for fiber-detector coupling is +/&#x2212;2 micrometers in contrast to a fiber-waveguide coupling which requires a reproducible accuracy of the process better than 0.5 micrometers. A reduction of coupling losses due to the necessary close tolerances is accomplished by waveguide tapers. The simulation, realization and results for such structures are presented in the paper. Also laser diode&#x2014;fiber connections require extremely close tolerances. The design of a micro-optical bench realized by plasma etching and a selfaligning soldering process is presented, which allows such tolerances.

Laser module and method for manufacturing the same

In a display device that displays a video by scanning coherent light across a screen, modulation at high speeds and gradation are necessary for a coherent light source. An oscillation wavelength of a semiconductor laser outputting the fundamental wave is changed at high speeds through the plasma effect induced by applying a pulse current to the coherent light source. A change of the wavelength causes the output of a higher harmonic generated in a light wavelength conversion element to change, and gradation is produced using such a change.

Coherent light source and control method thereof, and display unit and laser display using them

A method for easily and quickly evaluating the wavelength variability properties of a wavelength-variable semiconductor laser is provided. An inspection device includes a power source for supplying current to a wavelength-variable DBR semiconductor laser having an active region, a phase control region, and a DBR region, a photo-detector for detecting an output intensity of laser beam emitted from the wavelength-variable DBR semiconductor laser, and a transmission type wavelength-selection element that can be inserted into a light path from the wavelength-variable DBR semiconductor laser to the photo-detector. In a state where the transmission type wavelength-selection element is inserted into the light path from the wavelength-variable DBR semiconductor laser to the photo-detector, at least one of a phase current that is supplied to the phase control region and a DBR current that is supplied to the DBR region is changed with respect to a predetermined active current that is supplied to the active region, and the output intensity of the laser beam after the laser beam has passed through the transmission type wavelength-selection element is detected by the photo-detector.

Growing community of inventors

Osaka, Japan

Toshifumi Yokoyama