TV Lines Research Articles

A Wide-Aspect NTSC-Compatible EDTV System

A new single-channel, NTSC-compatible, wide-aspect extended-definition television (EDTV) system is proposed. It is an intermediate system, between the side-panel and letterbox systems. Unlike previously proposed intermediate systems, it widens the aspect ratio to 16:9 without using the horizontal blanking period. Moreover, it achieves 420 active lines using a bandwidth compression technique for side-panel signals. Conventional NTSC receivers display a center-panel portion of the widescreen image using 420 active lines, and side-panel signals are multiplexed into the remaining top and bottom areas of the image. High-frequency components are also transmitted, not only for the center-panel area but also for the side-panel area. This produces a high-quality, boundless widescreen image with more than 400 TV lines of horizontal and vertical resolution.

静止画の画質を評価するための空間周波数領域上の重み付け関数の実験的導出

A “weighting function” is defined for evaluating monochrome still-picture quality in the spatial frequency domain. The weighting values of the function can be determined from the relationship between the MOS (Mean Opinion Score) and the spatial-frequency-selective noise level. A hundred and six weighting values are calculated in the spatial frequency dommain of 256 (TV lines) x 256 (TV lines). When the ratio of viewing distance to picture height is 7, the weighting value at 3 (cpd, cycle per degree) shows maximum value. The function is isotropic in the region from 3 (cpd) to 8 (cpd) and anisotropic at over 10 (cpd).Using the weighting function, a new objective measure named WSNR (Weighted Signal-to-Noise Ratio) is also defined and applied to pictures degraded artificially. The picture quality is degraded by adding random noise, by passing through a two-dimensional low-pass filter, or by distorting blocks. Experiments using different portrait pictures show good correlation coefficients between the MOS and the WSNR, 0.93-0.97.

1280 x 1024 video rate laser-addressed liquid crystal light valve color projection display

An all solid-state 1280 x 1024 laser raster scanner (LRS) system conforming to the EIA RS-343 television standard with a limiting resolution of 1300 TV lines has been developed. The laser scanner incorporates acousto-optic devices to perform video modulation and X-Y deflection and is used in a time-multiplexed mode to photoactivate three liquid crystal light valves to project full-color, video-rate, large-screen images. Analysis ofthe LRS optical system, projection optics, electronics, and light valve characteristics is presented.

超高感度Ｓｕｐｅｒ‐ＨＡＲＰ撮像管

This paper describes the sensitivity of the HARP (High-gain Avalanche Rushing amorphous Photoconductor) tube. The sensitivity is 80 times that of a conventional tube e.g. SATICON or PLUMBICON), due to the use of a thick amorphous Se layer (6 μm), and a target voltage of 676 V. The tube, called Super-HARP, produces a high picture quality that is unattainable with conventional ultra-high-sensitivify image devices. It has a high resolution (maximum horizontal resolution of more than 800 TV lines), a low lag (decay lag in the third field of 1.6%), negligible additional noise, and no FPN (Fixed Pattern Noise) or blooming.

A 1/3-in 270000 pixel CCD image sensor

A 1/3-in interline transfer charge-coupled-device (CCD) image sensor with 270000 pixels has been developed. The effective sensing area of (4.8(H)*3.6(V)) mm/sup 2/ is adopted for the 1/3-in format. This sensor realizes 330 TV lines of color horizontal resolution. In addition, a new on-chip color filter is used, and a minimum object illuminance of 3 1x has been achieved. The electronic shutter was realized by developing the vertical-extraction method, with a wide range of shutter speed from 1/60 to 1/10000 s. Moreover, the use of an embedded photodiode makes it possible to achieve a low dark current. This feature, together with the 5-V drive, gives the sensor additional high performance, including low smear (0.01%). >

A 2 million pixel FIT-CCD image sensor for HDTV camera systems

A 1-in optical format frame-interline-transfer charge-coupled-device (FIT-CCD) image sensor with 2 million pixels and an aspect ratio of 16(H):9(V) has been developed for HDTV cameras. The effective number of pixels is 1920(H)*1036(V). In order to decrease the smear level, achieve uniform charge handling capability for the vertical CCD, and eliminate defects that appear as vertical stripes in the image of the device, aluminum wire was put onto the vertical transfer gate to decrease the resistance in the transfer gate and a dual-channel two-phase CCD was utilized for the horizontal shift register operated by a 37.125-MHz clock. As a result, this image sensor has a dynamic range of 72 dB and a sensitivity of 75 nA/lx for light with a color temperature of 2856 K. Smear is reduced to -100 dB by using the FIT-CCD image sensor structure. The horizontal limit is 1000 TV lines. In addition, image lag is negligibly small and below the sensitivity of the measurement instrument.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A 1/3-in 510(H)*492(V) CCD image sensor with mirror image function

A 1/3-in optical format 510(H)*492(V) interline charge-coupled-device (CCD) image sensor with a mirror-image function has been developed. To realize both a normal image and a mirror image, the horizontal shift register (H-CCD) is transferred forward and backward by a four-electrode, quasi-two-phase clock drive. The unit cell size is 9.6(H)*7.5(V) mu m/sup 2/. An on-chip microlens has been developed to achieve a sensitivity of 28 mV/lx, which is higher than that of the conventional 1/2-in device. The hole accumulation diode (HAD) sensor used has the advantage of low dark current, negligibly small lag, high blooming suppression, and a variable-speed electronic shutter. The smear reduction level is -83 dB. Horizontal resolution of 330 TV lines is obtained.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A 2/3-in 1187(H)*581(V) S-VHS-compatible frame-transfer CCD for ESP and movie mode

The authors present a high-resolution frame-transfer charge-coupled-device (CCD) suitable for S-VHS camcorders with an additional full-resolution true electronic still picture (ESP) mode of operation. The CCD sensor is composed of an image section, an intermediate readout register, a storage section, and a second readout register. A resolution of 450 TV lines (H) is obtained in color images by applying cyan-green-yellow complementary stripe color filters on the 1187(H)*581(V) pixels. The operation of the sensor in both conventional video and ESP modes is described. Special attention is paid to the 3-D potential calculations required to obtain a design guaranteeing a high-quality picture. Experimental results are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The dual green pickup experiment for a compact HDTV color camera with three-2/3 inch CCDs

A design concept for compact HDTV cameras is proposed. An experimental camera that has been developed in order to verify this concept is described. Since no 2/3-in HDTV charge-coupled devices (CCDs) suitable for compact HDTV cameras have been developed, 2/3-in CCDs (pixels: 766(H)*980(V), aspect ratio: 4:3) developed for a high-quality picture NTSC camera have been used as substitutes. The developed camera employs the three CCDs with spatially offset imaging between two green channels to improve resolution. Horizontal limiting resolution is over 900 TV lines, and vertical limiting resolution is about 800 TV lines. It is concluded that resolution deterioration due to the shortage of pixels can be compensated for with an adequate image pickup method and that it is possible to produce an HDTV camera that has relatively few pixels but has a well-balanced relationship between characteristics and resolution.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A 1" format 1.5 M pixel IT-CCD image sensor for an HDTV camera system

A 1-in. format 1.5-million pixel IT (interline transfer) CCD (charge coupled device) image sensor has been developed for an HDTV (high-definition television) camera system. To achieve a low smear ratio while maintaining a high level of sensitivity, the authors have developed a new impurity profile of a buried P/sup +/-layer and an on chip microlens array whose material is a deep-UV resist. Using this sensor, a high-fidelity picture with a horizontal resolution of 820 TV lines has been obtained. The IT-CCD sensor has achieved a smear ratio of less than -90 dB, a sensitivity level of 80 nA/Lx, and a maximum charge handling capacity of 1.2*10/sup 5/ electrons. >

CHARACTERIZATION OF SOMACLONAL VARIATION IN TISSUE CULTURE-DERIVED TANGERINE-VIRESCENT LINES OF TOMATO

The tangerine-virescent (tv) mutation was reported as a single gene somaclonal variant from tissue culture (Evans and Sharp 1963). A replicated field trial was conducted to characterize variation and stability in the phenotype of this tv somaclone and to compare it with the inbred parent from which it was reportedly derived.Heritability and stability of the tv somaclonal variant was measured by comparing R3 end R4 lines of sexual progenies of the original tv variant and with its sexually derived inbred parent UC82B. Several additional variants were observed in these tv lines, including fruit shape, days to first flower, fruit weight, yield, plant type, and fertility. Eight sterile or semi-sterile plants were discovered in 6 of 39 R4 lines. Our results suggest that multiple genetic changes have occurred in the tv somaclonal variant and while the original tv mutant is stably inherited, additional genetic abnormalities occur following sexual reproduction.

From 525/625 TV Lines to HDTV: The Evolution of Optical Requirements for TV Cameras

Two important requirements make HDTV lenses different from present television lenses. First, the picture is wider, and although the image may be scanned over the same sensor diagonal, the 16:9 aspect ratio makes it necessary to correct distortion better. Second, the quality of HDTV has to be twice as good; the same modulation transfer function (MTF) must be maintained, although the spatial frequency is twice as high. Although this level of performance is not, in fact, new to the optical designer who has already been involved with photography or motion pictures, his task is considerably more difficult because of the following constraints: (1) good camera sensitivity requires high aperture optics; (2) operational requirements dictate long zoom ranges; and (3) a beam-splitting prism is located between the lens and the sensors. This article explores in some detail what is needed and what can be done in order that the lens does not limit the performance of the HDTV system.

Wiener noise power spectra of radiological television systems using a digital oscilloscope

Measurement of spatial noise power spectra from television based radiographic and fluoroscopic systems is essential to the understanding of their operation and optimization. However, conventional methods require acquisition and processing of large numbers of complete images, thus confining such measurements to special applications where accessible frame buffers already exist or elaborately equipped laboratories. We have developed a method which only requires storage of single TV lines or point scans. A digital oscilloscope captures these point scans and a laboratory microcomputer facilitates manipulation of the data to separate out different components of the noise power spectra. The x-ray dependent component of the noise power spectrum so produced is not the ordinary Wiener spectrum. However, it is shown that reconstruction of the full Wiener spectrum from this is possible subject only to the requirement that the x-ray noise spectrum at the output of the imaging system is circularly symmetric.

HDTV single-chip CCD color camera

An HDTV (high-definition television) color camera has been developed by using a novel color-coding method, the field sequential color-coding method, to suppress spurious color signals. This camera has realized a high resolution of more than 850 TV lines without color moire and spurious color signals. Since the size and weight are 1/5 that of an HDTV 3-CCD color camera, it is suitable for both industrial and home use.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Development of the high-band 8 mm video system

To satisfy the demand for high-quality camcorder pictures, new tape, head, and circuits to deal with 0.5- mu m recording have been developed. Improved recording and editing features are implemented by introducing an improved ME (metal evaporated) tape. The high-band 8-mm video format is characterized by a higher carrier frequency, wider deviation, and a shorter pre-emphasis time constant than the basic 8-mm video system. In order to record short wavelengths, a high-performance tape and head are used, and to deal with the wideband signal, new circuits such as a positive feedback limiter, a wideband recording/playback amplifier, and a Y/C separator have been developed. The resulting system has not only a resolution of more than 400 TV lines, but also a high signal-to-noise ratio and a very clear waveform. >

Correlation of spot characteristics with perceived image quality

A project is described whose primary objective was to determine how much a spot must change in size on a projection CRT (cathode ray tube) before an observer could detect the change. This number is important in estimating the impact of CRT electron gun improvements on observed PTV (projection TV) performance. In order to quantify this subjective ability, the authors designed a focus survey experiment. The focus quality of a spot (i.e. spot size, shape, etc.) is significantly affected by focus voltage, therefore this measurable quantity becomes the numerical link between the subjective perception of the observer and a statistical analysis. The perceived spot size increment on a typical production 46-in projection TV having 330 TV lines of resolution by an average observer from a distance of 10 ft is PSSI/sub 50/=0.04 mm, PSSI/sub 90/=0.14 mm. >

Development of MUSE family systems

NHK has developed three ADTV (advanced definition television) systems that comply with US Federal Communication Commission's decision to maintain compatibility with existing NTSC systems: narrow-MUSE (multiple subNyquist sample encoding), NTSC (National Television System Committee)-compatible MUSE-6, and NTSC-compatible MUSE-9. All three systems use program materials produced in the 1125/60/2:1 format converted to the 750 line format and therefore can transmit a vertical resolution of approximately 750 TV lines. Among the three systems, narrow-MUSE has the highest quality, because there are no NTSC compatibility constraints. NTSC-compatible MUSE-6 has both NTSC and 6-MHz channel compatibility. So does NTSC-compatible MUSE-9, which also provides higher moving resolution by introducing a 3-MHz augmentation channel. The authors describe the features of these systems and the band compression techniques used.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

1/2-in 768(H)*492(V) pixel CCD image sensor

A sensor with unit cell dimensions as small as 8.4(H)*9.8(V) mu has been developed. In order to realize such a high-density device, the following technologies have been developed: (1) dual-channel horizontal CCD registers, (2) single p-well vertical overflow drain, (3) high-capacitance p-well structure, and (4) inverted-LOCOS channel isolation process. A horizontal resolution of more than 500 TV lines has been obtained. Maximum signal charge for the vertical CCD register is as much as 1.5*10/sup 5/ electrons, corresponding to 270-nA output current, in spite of a narrow-channel vertical CCD register with a mask width of only 1.8 mu m. The total random noise is less than 20 electrons after correlated double sampling. The dynamic range reaches 77 dB, and the photosensitivity is 0.092 mu A/ mu W. Experimental results also show that the technologies used here are effective for realizing a high-definition CCD image sensor for future use.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Super-Sensitive HDTV Camera Tube with the Newly Developed HARP Target

Conventional HDTV cameras lack sensitivity, so the iris must be opened two to three stops wider compared with practical cameras working within existing TV standards. This narrows the depth of focus, sacrificing picture quality. A more sensitive HDTV camera tube that combines a new high-gain avalanche rushing amorphous photoconductor {HARP) target and 2/3-in. high-performance magnetic-focus electrostatic-deflection (MS) electron optics is proposed. The combination results in a super-sensitive camera tube (10 times as sensitive as the Saticon) with an amplitude response of 36% at 800 TV lines (aspect ratio 4:3). This was achieved with no sacrifice in picture quality and no deterioration in resolution, lag, spectral response, or noise characteristics. After-image is negligible.

Direct-view and projection CRTs for HDTV

A series of direct-view and projection type CRTs has been developed for high-definition TV (HDTV) use. The technical aspects of direct-view 40-in and 30-in CRTs and projection 7-in and 12-in CRTs are described. The direct-view CRTs have an aspect ratio of 5:3 and a resolution of more than 1000 TV lines. With the fine and uniform pictures displayed over the entire screen, the CRTs are suitable for studio monitors and are also expected to be used for home TV sets. The projection CRTs have been developed for displaying picture size larger than 40 in. With the 7-in projection CRT, a resolution of 1000 TV lines and a peak brightness of 120 ft-L have been realized on a 50-in projection screen. With the 12-in CRT a 180 in projection screen with a peak brightness of 15 ft-L, about twice as high as a conventional CRT, has been realized.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>