`
`high-resolution TV to work in produc-
`ing movies, and broadcast networks
`will use it to enhance the quality of
`standard programing.
`CBShasstill another reasonfor pro-
`moting HDTV. It and other broadcast-
`ers require transmission channels to
`get these super-fidelity pictures into
`your home. For reasons detailed be-
`low, high-resolution TV can’t be car-
`ried easily on regular TV channels—
`and no one plans to disrupt today’s
`standard TV programing based on the
`525-line NTSC (National Television
`Standards Committee) format.
`But HDTVcan be transmitted into
`homes by direct-broadcast satellite.
`CBSis tellingofficials that it’s vital to
`reserve HDTV frequencies on a new
`class of satellites slated for launch
`within a fewyears.
`
`Morepixels, better picture
`How does HDTV differ technically
`from standard TV? Standard NTSC
`sets, functioning perfectly, can dis-
`play 483 (not 525) horizontal scan
`lines created as electron beamspaint
`TV pictures by sweeping back and
`forth over picture-tube phosphors.
`Each horizontal scan line can resolve,
`or display, 436 separate picture ele-
`ments, called pixels—an NTSC pic-
`ture can display 210,588 pixels.
`In practice, new sets equipped with
`so-called comb filters [PS, Aug.
`’78]
`show only about 330 horizontal ele-
`ments; most older sets average only
`about 250 picture elements per scan
`line. By contrast, although no firm
`standards have beenset, a 1,125-line
`HDTV picture might contain not
`twice but somefive times as many pix-
`els (one million) compared with an
`ideal NTSC image. Each one of the
`high-resolution scanninglines carries
`more image detail, and each is longer
`
`becauseof the wide-screen picture for-
`mat. As a result, high-resolution TV
`requires more frequency space, or
`bandwidth—typically, 30 MHz versus
`4.2 MHz for standard NTSC TV.
`“The NTSC system has given us
`very good service during the last 25 to
`30 years,” said Flaherty, “but we are
`pressing it to its maximum aspictures
`get larger and larger.” A demonstra-
`tion made this very apparent. Two
`cameras were set up in an adjacent
`room overlooking a street. One was a
`state-of-the-art CBS camera to dis-
`play standard 525-line TV pictures.
`The other was a 1,125-line model
`madefor Japan’s public broadcasting
`corporation (NHK).
`The 525-line camera piped its pic-
`tures to a Kloss projection TV before
`us with a six-foot-diagonal screen (and
`to regular TV studio monitors). The
`NHK HDTVcamerasentits pictures
`to a Matsushita-built wide-format
`projection TV and wide-format moni-
`tors (see color pictures).
`Pictures of a bowl of fruit were
`impressive on the 525-line Kloss and
`smaller monitors. But contrasted with
`the crystal-clear images on the HDTV
`sets, the limitations of NTSC pictures
`were dramatic. Training both cam-
`eras on the street below produced even
`sharpercontrasts. I could read license
`plates and other vehicle lettering on
`HDTVsets that were a hopeless blur
`on 525-line receivers.
`Whydo today’s sets have a squarish
`picture ratio four units wide and three
`high? “It was chosen for very simple
`reasons,” said Flaherty. “First, it was
`all we could do [technologically], and
`it was the way films were made,” he
`said, describing the 1940’s mono-
`chrome-TV format.
`An HDTVsystem unveiled by Sony
`Continued
`
`108|Pop
`
`PS SPECIAL HONE
`FLECTAGIMCS
`
`High-
`resolution TV
`— here come wide-screen
`crystal-clear pictures
`
`
`
`New video components
`speed TV systems that
`match 35-mm-film fidelity
`
`By JOHN FREE
`
`WASHINGTON, D.C.
`
`For several days, groups of govern-
`mentofficials, politicians, and jour-
`nalists crowded into a darkened room
`at CBS's offices here. We'd come to
`view a rare, one-timecollection of vid-
`eo gear. “What we are going to show
`you,” CBS's Joseph Flaherty, vice-
`president of engineering develop-
`ment, told my group, “is a combina-
`tion of high-resolution TV,
`stereo
`sound, wide-screen TV, and enhanced-
`color TV.”
`During the next hour I watched a
`variety. of amazing TV images that
`had extraordinary clarity—more than
`five times the detail of television pic-
`tures you see on conventional home
`receivers. The high-resolution pic-
`tures, a dazzling match for sharp-
`focus 35-mm slides, were shown on
`special “Cinerama-type” direct-view
`sets and a large-screen projection TV.
`Other equipment used by CBS, such
`as microelectronic encoding circuits
`and a Sony-built digital video record-
`er, may have a key role—in improved
`forms—in delivering this newtype of
`TV to you during the 1980's.
`Actually, so-called high-definition
`TV (HDTV) has been available for
`closed-circuit use in medical schools
`and business applications for a few
`years. But it has been limited to live
`transmissions using only cameras and
`TV monitors. Recently, professional
`videotape machinescapable of record-
`ing HDTV were unveiled. As a result,
`Hollywood directors may soon put
`
`
`PMC Exhibit 2100
`Apple v. PMC
`IPR2016-01520
`Page 1
`
`

`

`NOVEMBER 1981 | 109
`
`Projection TV displayed by Matsushita at technology exhibit in
`Chicago this summerusesred, green, and blue projection tubes
`like conventional models, but displays high-definition 1,125-line
`images from TV camera. Screen is 55 inches diagonally.
`
`Wide-screen high-resolution monitor developed by NHK and
`Matsushita has 30-inch-diagonal screen, 5:3 aspect ratio. Phos-
`phor dots are much smaller than on conventional shadow-mask
`tubes, and NHK usesa digital beam-convergence system.
`
`PMC Exhibit 2100
`Apple v. PMC
`IPR2016-01520
`Page 2
`
`

`

`last spring can showpicturesin stan-
`dard 4:3 format, the extra-wide Cine-
`mascope format, or an intermediate
`picture width. The high-resolution
`sets at the CBS demonstration had a
`5:3 picture-aspect ratio. In addition to
`letting you see mostorall of the pic-
`ture from wide-screen movies, sitting
`close to sharp, wide-screen HDTV
`images conveys more of the visual
`impact of a theater screen.
`Digital demonstration
`Warmingup in another CBSoffice
`was a special type of videotape record-
`er completed by Sony just six weeks
`earlier. Bill Connolly, managing di-
`rector of development for the CBS-TV
`network, prefaced another impressive
`demonstration: “Engineers today are
`generally agreed that digital
`tech-
`niques are the proper way to record
`this HDTV information and transmit
`it,” he said [PS, March ’78].
`Connolly explained that with con-
`ventional TV, voltage is proportional
`to brightness. The brighter the scene
`at any given point on the screen, the
`higher the voltage. Since the voltage
`is analogous to what's on the screen,
`it’s called an analog system.
`“The digital system does something
`quite different,” Connolly said. The
`voltage generated by the camera is
`constantly sampled or measured by
`digital circuits. Each of these samples
`is then assigned a binary number(ze-
`ros and ones) representing its inten-
`sity. This technique for each pixel on
`the sean lines requires considerably
`more bandwidth, or frequency spec-
`trum, for storage and transmission.
`While this large-bandwidth require-
`Pouring marbles
`ment is a problem, major efforts are
`Why, if digital coding of a TV signal
`under way to shrink the frequency
`takes up so much more frequency
`space needed for digital TV.
`spectrum,
`isn’t high-resolution TV
`“One of the things we can do is
`more feasible with analog signals?
`reduce the numberofbits [binary dig-
`High-frequency noise is one reason.
`its] necessary to describe a picture,”
`Noise, which can spoil standard TV
`Connolly said. He pointed to oneof his
`images, devastates HDTV.
`“favorite symbols,” a CBS eye glowing
`Connolly demonstrated another ad-
`on monitors. Running his finger
`vantageofdigital TV by first showing
`across one scan line on the eye, he
`a 525-line analog-signal picture of a
`explained that it carried about 150
`fruit bowl from tape. Then he showed
`black pixels, then 200 blue, and 150
`the samepicture after it had been re-
`black ones again.
`recorded 10 times—a tenth-generation
`“We wastea lot of [frequency] spec-
`copy. The image was smeared, full of
`trum with analog TV because we
`noise, and color values were shifted.
`transmit every one of those things
`For broadcasting, about five genera-
`using the whole bandwidth,” Connolly
`tions is the limit, he said.
`said. With digital techniques, though,
`But scenesthatfollowed from tenth-
`a single brief signal can be encoded
`and even twentieth-generation digi-
`that tells the digital circuits in the
`tally coded tapes seemed unaltered
`receiver to create 150 black pixels.
`from the originals. Connolly com-
`This coding of the digital signal,
`pared analog taping to pouring
`requiring perhaps only a few dozen
`water from one glass to others: Some
`bits instead of hundredsof repetitive
`water sticks to each glass; retaping,
`signals, cuts the rate at which bits
`similarly, robs parts of the original
`must be transmitted—plus bandwidth
`signal with each generation.
`requirements. Similar bit-rate-reduc-
`110|POPULAR SCIENCE
`
`Digital signals, by contrast, are
`either the presence or absence of
`pulses on tape. They survive trans-
`mission and taping much better, and
`Connolly compared the digital tech-
`niqueto pouring marblesfrom glass to
`glass. The marbles (digital bits) get
`through unchanged.
`CBSengineers were impressed with
`Sony’s new digital recorder. “In just
`seven years there’s been a 50:1
`improvementin the ability to jam bits
`into a small area of tape,” said Flaher-
`ty. “We went from under one million
`[bits] per square inch to 40 million.
`Weonly need a 3:1 improvement over
`that to record [digital] HDTV.”
`CBSalso presented an NTSC video-
`tape madewith stereo sound at a Ken-
`nedy Center concert. HDTV research-
`ers believe stereo is needed to bring
`the realism of wide-screen movies and
`other programs into your home. Dur-
`ing the demonstration of a Mozart
`operatic aria, repeated switching be-
`tween stereo and monophonic modes
`made stereo’s advantages obvious.
`HDTVoffers superior color, too. A
`future international high-resolution-
`TV standard will no doubt provide viv-
`id hues that can’t be obtained with
`NTSC color standards. Moreover,
`HDTV pictures can be transmitted
`with luminance(brightness) and color
`signals separated. Standard TV sig-
`nals have combined these—disastrous
`for picture fidelity—to achieve com-
`patibility between black-and-white
`andcolor receivers.
`You mayfirst encounter HDTV not
`on a TV receiver but displayed on a
`theater movie screen. Sony might
`lease its prototype HDTV gear within
`a year for Hollywood production work
`that would be converted to film. Vid-
`eotaping offers advantages in econo-
`myandflexibility.
`In a different application, CBS
`plans to use HDTV in about three
`years to enhance standardbroadcasts:
`HDTVtapes would permitspecial pro-
`duction techniques, such as image
`enhancement and zooming without
`picture degradation, before conver-
`sion to regular NTSC recordings.
`Also, cable TV and homevideodiscs
`and tapes may bring HDTVto you in
`the 1980’s. You would need a special
`receiver or player, but such sources
`could bypass the standards and regu-
`latory problems of broadcast HDTV.
`“The real question is whetherthis is
`going to be available to the general
`public or whetherit will be something ~
`only for the videophile with the money
`to buy all these ancillaries,” said Fla-
`herty. Getting wide-band HDTVinto
`broadcast channels, he said, “depends
`on the skill of the engineering commu-
`nity to makeit fit.”
`
`tion coding can produce the 200 blue
`and 150 black pixels for an “eye” scan
`line.
`John Rossi of the CBS Technology
`Center (Stamford, Conn.) demonstrat-
`ed a CBS 4:1 bit-rate-reduction sys-
`tem with an analog videotape ma-
`chine. An NTSC 525-line test pattern
`shown on monitors was created by a
`digitally coded signal that required
`only 28 megabits (millionbits) per sec-
`ond instead of the 144 megabits/sec.
`from the original digital sampling.
`“This is a very simple bit-rate-
`reduction technique,” Rossi said. “The
`circuits can literally be held in the
`palm of your hand. This leads us to
`believe that with more-complex cir-
`cuits much higher bit-rate reductions
`can be achieved.”
`“Failing these bit-reduction
`schemes, HDTV will not be broadcast-
`able,” added Flaherty. He hopestofit
`digitally compressed high-resolution
`TV into a normal or nearly normal TV
`channel. “Much work has yet to be
`done,” he said, “but you can see we’ve
`achieved a 4:1 reduction in bits fairly
`well, transmitting a roughly equal-
`quality picture.”
`That test-pattern picture I saw had
`somenoise but carried thefine detail
`indicating most of the image wasget-
`ting through. For this demonstration,
`anormal4.2-MHz, 525-line NTSCsig-
`nal became a 114-megabit/sec. digital
`signal that was compressedinto a 28-
`megabit/sec. signal. But that digital
`525-line signal would require about
`four VHF channels on your TV set. An
`HDTVsignal, even before it’s digital-
`ly sampled, requires aboutfive.
`
`
`
`PMC Exhibit 2100
`Apple v. PMC
`IPR2016-01520
`Page 3
`
`