A high-sensitive solid-state imager has been studied by connecting an avalanche multiplier film to MOS readout circuit via micro-bump electrodes. Optimization of the substrate temperature on Indium verpor-deposition made it possible for micro-bumps of 4μm width and 5μm height to be formed into a 2/3-inch matrix array of 380k pixels. In a prototype imager, clear avalanche multiplication of about ten times was observed. The imager has a good resolution and no recognizable after-images.
A new type image sensor cell which can reduce a random noise, has been proposed and evaluated with a cell test element. The new type cell structure is featured by the signal voltage feedback gate (FBG). The FBG is inserted between a storage diode and a CCD register, and it controls the signal read-out channel potential. The random noise which occurs at the signal charge storage diode has been reduced from 42 electrons [rms] to 18 electrons [rms] for 5 fF storage diode capacitance.
To realize single layer electrode CCD, optimum condition for potential pocket suppression are studied by using channel potential simulations. Under the condition, a single layer electrode CCD is fabricated and the charge transfer efficiency and maximum amount of signal charge are evaluated.
We propose the Deposition type Volcano-shaped Emitter in this paper. Electron emission could be observed at low gate-voltage of 35V. Using N-doped Diamond Like Carbon (DLC) as emitter, it was found that the effective work-function of the emitter can be reduced compared with Poly-Si emitter.
A floating field emitter including a photo-sensitive p-n junction could be fabricated using a-Si : H photodiode. The photo-detection corresponding to the incident light flux was confirmed from the experimental characteristics.
We propose an a-Se avalanche-type image pickup tube with a hole blocking structure using carrier trap layer. A highly LiF doped a-Se thin film is used as the hole trap layer which makes the dark current less than 1nA. The lowered dark current enables much Te doping into a-Se and consequently signal current for the red incident light reaches twice as much as that of conventionl one.
This paper describes design and experimental results of a newly devised CMD imager which has a wide dynamic range. In order to extend dynamic range of the conventional CMD imager, we utilized non-destructive readout capability and electrical shutter operation of CMD devices. Wide dynamic range images can be obtained by combining two image data with different exposure periods. When the shorter exposure period was set at 8H, the dynamic range extend greater than 80dB.
We have developed a dynamic range extended color camera system using CMD(Charge Moduration Device). The system produces 15 bit dynamic range video signal using two signals at different exposures ; normal exposure signal in a field peirod and short exposure signal using NDRO(Non-Destructive Read Out). Obtaind dynamic range is 16 times as wide as that of conventional camera systems. This proposed method also provides excellent color reproduction.
There were many proposal about camera with CCD imagers. We have applied electronic shuttering scheme to three CCDs color camera in order to extend dynamic range. A summary of this experiment is reported in this paper.
This paper describes an HDTV image extracting system from a very high resolution image. Through a serial digital interface, this system receives the image data from the 4K×2K image acquisition system which we have developed and extracts an HDTV image from the inputted data. The extracted area can be scrolled with the precise of one pixel. The system will enable the use of electronic zooming and the generation of a variety of background scenes in composing electronic scenes.
Digital transmission utilizes a newly developed time-division multiplex method that allows bi-directional serial digital transmission between the camera head and camera control unit over standard triaxial cable.
A new architecture for massively parallel vision chip has been proposed. The vision chip has general purpose processing elements (PEs) with photo detectors and is programmably controlled. It is shown by simulation that the vision chip based on our architecture consists of only 700 transistors per each PE and can implement various visual processing algorithms at high speed. The sample design based on this architecture has been implemented into an FPGA chip.
This paper presents a newly-developed Neuron-MOS circuit that handles moving images and detects their motion in real time. The motion vector detection is one of the most time-consuming processing and takes a few 10 milliseconds even with the most dedicated DSP chips. A Neuron-MOS motion-vector detector features very simple circuit configuration and can find the movement of an image in a few 100nsec based on quasi-two-dimensional image processing. Test circuits were fabricated by a double-polysilicon CMOS process and their basic operation has been demonstrated.
This papaer presents a newly-developed neuron-MOS (νMOS) cricuit that can track the center-of-mass(COM) of a moving image on a two-dimensional pixel array in real-time with very simple cricuit configrations. Test cricuits were fabricated by a double-polysilicon CMOS process and the opertation of the circuits has been experimentally demonstrated.
In this paper, we propose motion adaptive enhancement sensor on image sensor by controlling storage time independently pixel by pixel. The proposed sensor is able to control the suitable storage time in each pixel which results in no-motion-blur and no-saturation, and it is expected to have high temporal resolution in the moving area and high SNR in the static area.
We propose a signal scanning method for image sensors using a tree structure of automata. We compared the new scanning method with the conventional raster scanning, and show the possibility of the new scanning to archive shorter code length especially in case of less number of active pixels.
We have designed a CMOS circuit which scans active parts on image sensors selectively with capability in real time. and this circuit has been on FPGA (Field Programmable Gate Array). In this paper we whow that this method gives shorter code length, and that it is also possible to decode with a simple circiut.
We investigate a new computational image sensor which compresses image signal in the process of image acquisition. We design a new compression sensor, in which power consumption is improved and circuits for controlling rate and address is implemented. We fabricated a prototype compression sensor in a 2μm CMOS technology.
We have studied a new computation image sensor that compresses image signals during image acquisition. The prototype sensor was evaluated for pixel performance and flag signals. High-speed operation of up to 1200 frames per second was realized. Furthermore, flag signals appeared in response to object movements. Consequently, it is promisting for implementation as a high-speed video-compression sensor.
A parallel architecture is proposed for analog DCT operations using floating-gate transistors with differential inputs and feedback. All operations are in voltage mode. Only one terminal is required for the feedback which is capable of suppressing the distortions due to active elements. Implementing DCT operation circuits together with an array of photosensors, an image compression sensor can be realized.
It is known that hot electrons that excite lunimescent centers are injected into an emitting layer from p-Si as a result of a band bending in Si at the interface between SiO_2 and p-Si. Therefore low voltage driving of a EL device is expected. In this study, a thin-film EL device is prepared on p-MOSFET in order to apply this fact. Luminance of about 10cd/m^2 was obtained from ITO/ZnS : Tb/SiO_2/p-n Si/Al device structure.
Ce-doped calcium thiogallate (CaGa_2S_4 : Ce) thin films for blue-emitting thin film electroluminescent devices have been prepared by multi-source deposition technique using Ca metal, Ga_2S_3 and CeCl_3 source. The thin film consisted of CaGa_2S_4 and GaS was prepared at a substrate temperature of 550℃, a flux ratio, Ga_2S_3/Ca, of 70.
Ce-doped Sr thiogallate (SrGa_2S_4 : Ce) films for blue-emitting thin film electroluminescent devices have been prepared by multi-source deposition technic using Sr, Ga_2S_3,and CeF_3 source. The SrGa_2S_4 : Ce film showing blue luminescence with peak 445 and 490nm was deposited at a substrate temperature of 450℃, a flux ratio of Ga_2S_3/Sr=300 and at a anneal condition of 600℃ for 3 hour.
A dot-matrix type display has been developed using Organic EL devices. A pixel number of 256×64 with pixel size of 0.34mm×0.30mm, a luminance of 100cd/m^2 and a contrast ratio of 100 : 1 or over have been achieved. The display provides high luminance, high visibility and wide viewing angle.
It has been tried to make the phosphor conductive by making a thin In_2O_3 layer on the surface of the ZnS : Ag, Cl phosphor particle. It was shown that the luminance of the phosphor excited with lower voltage than 500V improved considerably by the formation of In_2O_3 layer. Further, it was found that the formation of In_2O_3 layer is also effective for the improvement of the aging characteristics of cathodoluminescence.
We have developed the high sensitivity deflection yoke (DY) for 41cm super high resolution color display. It has adopted to a color display tube with Φ24.3mm neck and reduced leakage magnetic field without magnetic field canceling coils. Furthermore, it has a circuit board on its rear portion.
We fabricated the Field Emitter Arrays with n-type silicon wafers, and those covered them with W and Cr. The applied voltage for field emission from FFAs covered with W and Cr are lower than that from Si-FEA. Native oxide layer prevent from emitting.
A 40-inch diagonal full color AC-plasma display empoying a new cell design and new driving techniques was developed. The display has a luminous efficiency of 1.2lm/w, a white peak luminance of 350cd/m^2,256-gray levels, and a contrast ratio of 150 : 1. The picture quality is comparable to that of CRT displays.
In order to improve color ac plasma displays, we investigate new materials of protecting layer which has transmissive property of ultraviolet rays. We measured the characteristics of ion induced secondary electron emission for protecting materials.
In the reflective LCDs using birefringence mode, the phase difference and depolarization of reflected light by diffusing reflector were considerd to important problem. Then we have analized the reflective properties and shown that the problem is not severe. Therefore, teh above mentioned LCDs are promissing to the practical displays.
We have proposed a novel reflective LCD using hybrid aligned LC cell (HAN-cell), mirror electrode inside of the cell and front scattering film. In this paper, we proposed an advanced LCD using a Light Control film (LCF) insted of the scattering film. This LCD has wider viewing angle, higher brightness and higher resolution and is promissing to the full color reflective LCD with gray scale capability and fast response.
A ultra-wide viewing angle 20inches diagonal SXGA (1280×1024) color TFT/LCD was developed. Excellent picture image superior to CRT was obtained. Especialy, advantages of LCD picture image distortion free, sharp image etc) can be recognized vividly. This LCD is suitable for high-end graphic applications.
We have proposed a concept of multi-media low power driving method using MFD in which a displayed image was divided into some interlaced subfield images and the number of interlaced subfields can be changed depending on the moving quantities of displayed images. We demonstrated the power reduction effect without moivng image degradation by applying this method to a 9.5"TFT-LCD.
A high-brightness rear type projector using a 10.4inch color liquid crystal panel has been developed. The optical illumination system consisting of four metal halide lamps and optical integrators has improved the brightness and uniformity of the projected image. A fresnel lens with suitable lens pitch and inclined non-lens surface has contributed to the reduction of both the size and the cost of an optical projection lens.
The new multimedia service <G-COM> that uses FM sub-carrier data broadcast was started. This service needs new FM sub-carrier data format to send a data. We developed the receiver for this service. And We contributed to develop the new format.
We have developed a new compensation method for cluster image defects in solid-state imaging devices since conventional methods are for one or two pixel defects. The features of the present method are as follows : (1) suitable for edges which pass through cluster image defects (2) sufficient processing time which enables the use of software in the case of a digital still camera (3) low cost
A cost effective L-SECAM chroma processing IC for VCR has been developed. Various filters and identification circuit have been integrated. The entire circuit is adjustment-free and requires one peripheral crystal. By optimizing the system structure, both the high picture quality and the total cost reduction can be achieved.