End Of An Era: CRT Technology In Large Format Display
Like its name, a large-format video display is a large display with purpose to show full-color moving images to a large crowd of spectators. The program material is usually some combination of image magnification, it could be sports instant reply or advertisements. Whatever the content might be, the one thing they must have in common is that they are true video sources.
The large-format displays are typically used in venues where a very large number of people must be able to see from distance such as in sports arena or in a pop concert. True to its name, the display are generally 10 to 50 feet width and bright. The bright quality in large-format display is meant to overcome high ambient light such as television or theatrical lighting. For screens of such size, there have been only two viable technologies: CRT and LED. There are no other technologies even the ones like video projection, videowall cubes, and lamp-based matrix signs have proven unsatisfactory for the task.
Before LED, CRT technology played solo technology behind the large-format display. But with the advance LED technology, CRT technology has started being viewed as the traditional (technology) one for large-format display. In fact, LED technology has surpassing CRT technology not only in the aspect of resolution and brightness. Well, let’s take a detail look at each of these large-format display technologies...
The Cathode Ray Tube or CRT is a vacuum tube containing an electron gun and a fluorescent screen used to view images. CRT has means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. Image may represent electrical waveforms, pictures (television, computer monitor), radar targets and others. Different from other large-format display usage, CRT technology has also been used as a memory devices.
The original giant screen technology, these screens have now been superseded by LED technology. The examples of CRT technology screens are the Mitsubishi Diamond Vision, Panasonic Astra Vision and SONY JumboTron in large-format displays with high ambient light situations such as a stadium or an arena.
Just as with a newspaper photograph, the video picture is divided up into a number of dots called pixels. Each of pixels in CRT technology is made up of at least three tiny cathode ray tubes. One color is red, one green and one blue. An image in CRT technology is produced by controlling the intensity of each of the three electron beams, one for each additive primary color (red, green, and blue) with a video signal as a reference.
By varying the brightness of each of these, any color can be created. Each of these CRT technology is like a tiny television picture tube, except that it is producing only the intensity of one picture dot, and the entire picture is made up hundreds of thousand of CRTs, resulting to a large, bright video image.
LED technology or Light Emitting Diode has started to advance in the late 90s. In means of large-format display, LED technology has began rivalling and surpassing the resolution and brightness of CRT technology. However, LED technology actually works with the same principal like a CRT technology. But the tiny Cathode Ray Tubes are replaced by LED tubes.
The good about LED displays is it consumes far less power with considerably lighter results than the CRT-based counterparts. That, coupled with the fact that they occopy less volume (they are less than half as deep), has made LED technology more attractive compares to CRT technology. Especially because CRT technology has been limited to three principal vendors primarily due to the complexity of the manufacturing process.
LED technology on the other hand, is far more accessible. Resulting in about 50 listed manufacturers. But it is not without weakness since such accessibility could risk to some poorly designed product and some short-term manufacturers who may sell only a few systems before vanishing. That is why selecting a manufacturer with a track-record is highly advisable when buying a large-format display with LED technology.
Until mid 2000s, most forms of image-viewing devices are based upon CRT technology. But now the mainstay of display technology for decades has been considered a dead technology. The demand for CRT technology displays has dropped precipitously since 2000s and had accelerated in the latter half of the decade. The end of most high-end CRT technology was marked around 2006, when Sony closed down its picture-tube factory in San Diego and started to produce its CRT technology displays in South East Asia, following the footsteps of its competitors. A year before, in 2005, Sony announced that they would stop the production of CRT technology displays for computer.
In Canada and United Statesm the sale and production of high-end television with CRT technology reportedly had ended in 2007. A couple of years later, inexpensive 20 inch combo CRT technology TVs started to dissappear from discount stores. With those facts, market analys’ predicted the dissappearance of CRT technology based large-format display within five or six years time. Despite the large-format displays in general are still capable to deliver satisfactory performance for much longer time.
Technology companies are also responding to the trend. Electronics retailers such as Best Buy have been steadily store spaces for CRT technology displays. Furthermore, Korean manufacturer Samsung, no longer introduce any CRT technology based products since 2008. Samsung had removed their 30 inch wide screen CRT technology TVs from the company’s American branch website and has not replaced them with new models.
The demise of CRT technology has reportedly been happening more slowly in the developing world. According to iSupply, production in units of CRT technology was not surpassed by LCDs production until the fourth quarter of 2007, thanks to the CRT technology display production at factories in China.
Despite its rapid dissolve from the (large-format) display market, CRTs (technology) are still use for displaying photos with high pixels per unit area and correct color balance. The CRT technology also still finds popularity in the printing, broadcasting and graphic industries due to its greater color fidelity, contrast, and wider viewing angle. The CRT technology also still considered adherents in video gaming and widely used in the study of brain’s visual processing. Since the technology offers various qualities that makes them well-suited for the kind of experiments where scientists need to have fine control over stimuli while its being presented to an observer.
For a large-format display, CRT technology might have lost its appeal to LED technology, but the technology has surely found resurgence in specialized markets. Not quite the end of an era, then.
(Date: 18 June 2013; Frida)