SIC 3671

This category covers establishments primarily engaged in manufacturing electron tubes and tube parts. Establishments primarily engaged in manufacturing X-ray tubes and parts are classified in SIC 3844: X-Ray Apparatus and Tubes and Related Irradiation Apparatus; those manufacturing liquid crystal displays (LCDs) are classified in SIC 3679: Electronic Components, Not Elsewhere Classified; those manufacturing computer terminals are classified in SIC 3575: Computer Terminals.

NAICS Code(s)

334411 (Electron Tube Manufacturing)

Industry Snapshot

The number of companies engaged in this industry in the late 1990s totaled 158, down by 15 percent from the number of firms in the early 1990s. Yet these establishments generated just under $3.8 billion in shipments in the late 1990s, a 19 percent increase over the value of shipments in the early 1990s. Shipments in 2000 declined to $3.56 billion. The industry employed 16,187 individuals in 2000, down considerably from 21,656 in 1997. As a result, total payroll costs over the same time period decreased from $726 million to $633 million.

Over three-fourths (76 percent) of the value of industry revenues in the late 1990s was derived from the production of new and rebuilt receiving-type electron tubes such as TV and cathode-ray tubes, up from only 61 percent in the early 1990s. The second major product group, accounting for 17 percent of the value of late 1990s shipments, consisted of transmittal, industrial, and special-purpose electron tubes (except X-ray tubes). This represented a decline from 31 percent of total industry revenues earlier in the decade.

Organization and Structure

The two most recognizable types of electron tubes were the ordinary television and computer tube and the once common vacuum tube traditionally used in radios and other electronic equipment. Generally speaking, electron tubes were sealed glass, enamel, or metallic tubes of varying sizes into which electrons were fired for the purpose of displaying images or conducting, transmitting, or multiplying light for nondisplay purposes. Although television tubes and computer displays were the most common products, industry firms also manufactured camera tubes, microwave tubes, Geiger counters, radar screens, and such specialized devices as electron beam (beta ray) generator tubes, klystron tubes, magnetron tubes, planar triode tubes, and tubes for operating above the X-ray spectrum.

Electron tubes varied according to the extent to which they were "evacuated," or emptied, of gases and vapors; by the capability and type of the electron source; and by the number and configuration of electrodes they contained. The amount of power used in electron tubes ranged from milliwatts to hundreds of megawatts, and the frequency of operation ranged between zero and ten-to-the-eleventh-power Hertz depending on the type of tube. In general, CRTs operated by playing a beam of electrons of varying intensities over a display surface such as a phosphor screen, which formed patterns of light that took the form of characters or images. The three basic components of a CRT were the envelope, the electron gun, and the phosphor screen. The envelope, which was usually made of glass, was a funnel-shaped element through which the electrons were fired toward the faceplate on the broad end of the envelope. The electron gun was the source of the electrons, which, when heated and formed into a beam, were directed to differing parts of the screen by magnetic fields surrounding the envelope. The phosphor screen itself consisted of a layer of phosphor dots that coated the inner surface of the CRT's faceplate. Color CRTs used a screen made up of red, green, and blue phosphors, with an electron gun for each color; monochrome CRT screens employed one electron gun.

In the everyday family "direct view" TV, the face of the picture tube on which the electrons are projected is the same as the screen the viewer sees. In rear-projection TV sets, which became increasingly common in the 1980s, a translucent screen was used against which images were projected indirectly from three small CRTS (one each for the colors red, green, and blue) through a series of mirrors. In the mid-1990s projection TV tube manufacturers were using compact CRTs and lenses with shorter focal lengths to reduce the amount of space taken up by the television box, reducing the size of the once bulky rear projection sets by a third. In contrast to the 4:3 aspect ratio of the standard television tube, wide screen TVs employed a 16:9 ratio that resembled the wide ratio of movie theater screens and were therefore marketed as the precursor to the so-called high-definition television (HDTV) technology that Japanese TV makers trumpeted throughout the 1990s. With the advent of advanced data streaming technology, computer CRTs were increasingly used to display downloaded and/or Digital Video Disk (DVD) movies and multimedia entertainment.

Despite its continued popularity in the 1990s, the CRT was by no means a perfect piece of technology. In a world increasingly permeated by digital solid state electronics technology, the CRT remained the last holdover of the old analog glass vacuum tube, which in fact it essentially was. The CRT was bulky, hot, and heavy, used large amounts of power, and was prone to disruptions of glare and magnetic and electrical fields. By the mid-1990s, in fact, few experts doubted that for mainstream computer and TV uses the CRT's days were numbered. In their place, came the advent of high definition liquid crystal display (LCD) screens for computers. These displays utilized an active matrix view panel. Display resolution often surpassed the capabilities of traditional CRT displays. While such technology was often far more expensive, the promise of ever-decreasing manufacturing costs and higher consumer demand marked LCD technology as the heir-apparent to traditional CRT use for computer displays.

The second largest industry product group, transmittal, industrial, and special-purpose electron tubes, included electro optical tubes, miscellaneous special-purpose tubes. The electrooptical tube segment included everything from camera tubes and photo cells to other photo-conductive and photo-emissive tubes, most notably the airport bomb detector picture tube, the largest market of the electro optical tube segment.

Microwave tubes were primarily used in high and ultrahigh frequency applications such as radars, telecommunications equipment, military communication and control systems, high-frequency microwave ovens, scientific research equipment, FM radio transmitters, and industrial heating equipment. Traveling wave tubes, which were divided into forward and backward wave electron tubes, accounted for a majority of the microwave electron tubes produced. Microwave tubes as a whole comprised a majority of the power and special-purpose tube market. Gas tubes were used primarily in industrial applications because of their efficiency and ability to handle high levels of power or current at generally low frequency levels. Product types included diodes, rectifiers, control-type industrial triodes, hydrogen and nonhydrogenthyratons, and other gas and vapor tubes. High-power tubes were also used in broadcasting transmitters. Vacuum tubes, once the primary element in electrical circuits, were primarily used in applications where low noise and high frequency were involved.

Background and Development

Electron tubes were the principal components of almost all electronic circuits and equipment until semiconductors were developed and began to replace them in the late 1940s and 1950s. The first application of CRT technology was for an oscilloscope in 1897, and the first television using a CRT was developed in the late 1920s. Commercial production of monochrome television picture tubes began in the late 1940s. After World War II, U.S. electron tube manufacturers found a diverse and lucrative market in defense applications, ranging from radar to communication and control equipment.

By the mid-1990s, the fastest-growing segment of the TV picture tube market was big-screen TVs, those providing from 31 to 58 inches of viewable screen image. Despite the fact that by the mid-1990s nearly every U.S. home had at least one TV, there were 22.9 million direct-view TVs sold in 1999. In 1994 over 26 million color TVs were sold in the United States. Spurred on by a demand estimated to reach $20 billion by the turn of the century, industry firms were making significant strides in improving CRT's resolution, brilliance, size, energy usage, and cost. Television tubes and computer monitors were becoming flatter and bigger (the standard 14-inch PC monitor, for example, was giving way to 17- and even 20-inch models), digital circuits were being used to enhance picture quality, and advances in nonelectron tube technology were coming on so quickly that the CRT itself seemed destined for only niche uses in specialized applications.

Current Conditions

In the 1990s the CRT sector of the electron tube industry continued to establish itself as the sector's primary revenue machine. Despite a drop-off in government spending for military-related CRT display technologies, the consumer computer CRT and television tube markets provided more than enough demand to fuel the industry's continuing growth. Between 1994 and 1999, the value of PC system sales (which included a CRT monitor) grew by almost 77 percent. Concurrent expansion occurred in the number of systems sold, which increased over the same period by 121 percent. A total of 90.5 million CRTs were sold in 1998 and generated a $17.2 billion market share of the electron tube industry. Monitor Market Trends projected an increase to 134.7 units sold by 2004, but due to a decline in per unit cost, forecasted that revenues would only increase to $18.9 billion.

In the late 1990s the battle between the computer CRT and the flat panel display (FPD) intensified. Developed in America, but later co-opted by Japanese firms, the FPD encompassed several display technologies, from active- and passive-matrix liquid-crystal displays (LCDs) to field-emission, micro mirror, diamond emission, and neon- or xenon-based gas plasma displays. By the late 1990s, FPD manufacturers had overcome hurdles in FPD design complexity and subsequent high cost and the technology's high power requirements. At one time, the only CRT markets immediately threatened by FPDs were point-of-sale terminals, medical imaging applications, and displays for instrumentation and factory automation. However, when the twentieth century ended, manufacturers had broken out of the laptop and avionics display markets into the television tube and PC monitor markets, the electron tube's home turf.

Flat panel display technology began to find application in a wide variety of uses at the close of the 1990s. According to the U.S. Display Consortium (USDC), innovative uses included analytical equipment, conference-room equipment, marine instruments, hand-held devices, electronic books, passenger entertainment systems, and home appliances. So-called "cutting-edge" technology also included filed-emission displays (FEDs). According to Electronic Business , total revenues from flat panel display sales at the end of 1999 were estimated at $11 billion.

Throughout the 1990s high-resolution HDTV was marketed as the next great advance in television technology. Because its superiority was only noticeable in 40-inch screens, the resulting increases in TV tube size spelled more trouble for the electron CRT's future. As the resolution of television screens increased, the brightness of the traditional CRT fell, and the FPD became no more expensive than a comparably sized CRT, but 75 percent thinner. In addition, the distinction between the television tube and the computer monitor threatened to vanish as technologies like Zenith's "NetVision" allowed consumers to watch TV or surf the World Wide Web from the same screen.

Total industry shipments declined from $3.82 billion in 1999 to $3.56 billion in 2000, while the cost of materials increased from $2.08 billion to $2.21 billion. Employment in the industry declined steadily through the late 1990s and 2000, falling from 21,656 in 1997 to 16,187 in 2000. The number of production workers over this time period dropped from 16,774 to 12,718.

Industry Leaders

Among the leading firms in the electron tube industry in the 1990s were Zenith Electronics Corporation, Philips Display Components Company, Hitachi Electronic Devices, and Toshiba Westinghouse Electronic. Other major industry players included GM Hughes Electronics Corporation, Hewlett-Packard Co., ITT Corporation, Litton Industries Inc., Electron Devices Division, Philips Electronics North America, and Raytheon Electronic Components. The pace of change in the electron tube industry was frenetic in the mid-1990s. In 1994, Display Technologies Inc., a joint venture of International Business Machines Corporation (IBM Corp.) and Japan's Toshiba Corporation, continued to develop IBM's flat-screen CRT product line. The same year, Fluke Corporation sold off its CRT operation, and in 1995, Advanced Technology Materials Inc. and Silicon Video Corporation agreed to market a new generation of thin CRT flat panel displays. Varian Associates Inc., once an industry leader, sold its electron devices operations to Leonard Green & Partners L.P. for $200 million in 1995. In 1996 Japan's Sony Corp. and the U.S. firm Tektronix Inc. unveiled a big-screen "Plasmatron" television line that offered consumers a 25-inch flat-screen television (about four inches thick), with 40- and 50-inch flat TVs to follow.

With LCD/FPD technology establishing a strong foothold in the market for displays and TVs, upcoming leaders in the industry were often a result of joint ventures among recognized, historical leaders. One of the most active of these collaborations was Display Technologies Inc., which was the result of a venture between IBM Corp. and Toshiba Corp. Other LCD/FPD leaders at the end of the 1990s included TEAC, Epson America Inc. (the U.S. affiliate of Japan's Seiko Epson Corp.), Fujitsu Microelectronics Inc., Hitachi, and NEC Electronics Inc. Leaders in the newest of flat panel technologies, thin-film-transistor (TFT) displays (most notably used for huge multimedia displays for rock concerts and sporting/recreational events) were Hitachi and Sharp Electronics Corp.

Research and Technology

The growing demand for computer monitors for use in homes and offices starting in the 1980s forced industry firms to develop more user-friendly monitor designs, such as the "flatsquare CRT," in which the curvature of the CRT's screen was greatly reduced. CRT display technology also continued to evolve in the areas of unit price and color display capabilities.

The application of multifunctional CRT displays in the instrument panels of military and to a lesser degree commercial aircraft also continued in the 1990s. However, the inherent disadvantages of CRTs—limited screen size, unwieldy shape, high power requirements, and fragility—led manufacturers to investigate alternatives to CRT technology, such as light-emitting diodes, FPDs, and LCDs. Improvements in LCDs, which were thinner and lighter than CRTs, enabled them to compete in price with CRT-based, large-screen, video-data projectors while offering roughly 2 to 4 times their brightness. In aircraft cockpit applications in particular—where limited space and high levels of glare diminished the usefulness of CRTs—flat panel displays increasingly emerged as the favored display technology. Another emergent technology, the field emission display, was structurally less complex than LCDs and even thinner in size and further threatened to unseat the electron CRT. In general terms, field emission displays were based on vacuum microelectronics and combined the advantages of the old vacuum tube technology with the benefits of digital computer chips. Advances in research and technology also continued in non-CRT product categories in the 1990s. Direct broadcast satellites for noncable, HDTV transmissions (among other uses) were developed that used electron tubes, such as traveling wave tubes, for satellite tubes and uplink stations with tube lifetimes of up to 15 years.

As the twenty-first century began, electron tube technology continued to evolve. In addition to well-known applications such as CRTs for television and computers, advances in the way electron tubes were configured opened up new applications and markets. Using technology developed in 1997 by Lawrence Livermore National Laboratory researchers Booth Myers, Hao-Lin Chen, Glenn Meyer, and Dino Ciarlo, new designs eliminated the need for vacuum systems used in conventional electron beam equipment. The new, sealed electron tube reduced cost tenfold, were smaller and easier to use, and (in high-risk applications for X-rays and high electrical voltages) reduced worker exposure. This technology made possible applications as diverse as processing inks, adhesives, paints with greatly-reduced pollutants, processing floppy disks for computers, and medical supplies.

Further Reading

"ATMI, SVC Expand CRT Partnership." Electronic News 41, no. 2062,24 April 1995, 4.

Barry, James. "Big Screen Bonanza." Stereo Review 60, no. 4, April 1995, 53+.

"Beyond Laptops." Electronic Business , January 1999.

Britt, Russ. "One-for-all, all-in-one." Electronic Business , December 1999.

Cataldo, Anthony. "CRTs Are Solid Fixtures but FPDs Keep Pressing On." Electronic News 41, no. 2070, 19 June 1995, 68.

Churbuck, David C. "The Last Picture Tube." Forbes 155, no. 10, 8 May 1995, 136+.

"Commerce Department/The McGraw-Hill Companies Forecast Continued Economic Growth." Business Wire , 21 November 1997.

"CRT Monitors Continue to Fend Off Flat Panel Challenge; Market Will Top $17 Billion in 1998." Business Wire , 19 October 1998.

Delano, Daryl. "Solid Growth for Consumer Electronics." Electronic Business , February, 1999.

"Extra: Top Component Suppliers: Displays." Electronic Buyer News , 3 November 1997.

"Information Impact." Fortune (technology guide supplement), Winter 1997, 93+.

Lawrence Livermore National Laboratory. "Livermore Researchers Garner Three Awards for Successful Projects with U.S. Businesses." U.S. Department of Energy Information Locator, 1998. Available from;doecrawl-028326/ .

"Preparing for Prime Time," Economist 340, no. 7980, 24 August 1996,49.

U.S. Department of Commerce. "Electron Tube Manufacturing." 1997 Economic Census, Manufacturing Industry Series . Washington: GPO, 1999.

United States Census Bureau. "Statistics for Industries and Industry Groups: 2000." Annual Survey of Manufacturers. February 2002. Available from .

"Varian Sells Off Electron Devices." Electronic News 41, no. 2081, 4 September 1995, 40.

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