Functionality Assesment Of CRT, LED, Plasma TV Receiver

ABSTRACT

The quest for a better television (TV) and monitor displays for home theaters, business and academic programs gives rise to the progresses in video display technologies. The flat screen TV technologies have taken over the consumer market against the old bulky CRT TV technology displays. Again, researches have shown that Plasma based televisions, are better in their display features than, the liquid crystal display (LCD) based televisions. However, there are some complications associated with Plasma TVs especially in distribution, which made LCD TVs most common in the consumer market.

CHAPTER ONE

1.1                                                        INTRODUCTION

There are several primary types of technologies used for monitors and televisions, including CRT and LCD in addition to plasma and projection displays [8].Instead of relying on traditional cathode ray tube technology, which is the driving force behind standard, bulky TV sets, plasma and LCD flat panel TVs rely on more advanced video display technology such as 3-Dimensional (3D) and High Definition (HD) TVs. And while plasmas and LCDs have some similarities, they differ in terms of function and performance. Plasma and liquid crystal display televisions are both flat-panel televisions that users commonly mount to walls or rest on mantels [2]. The unique reaction that creates a plasma display has several benefits over other display formats, such as CRT and LCD monitors, but it has several limitations as well [11].

As high-definition (HD) technology progresses, consumers are given more and more options for their home theater and computing needs. Cathode ray tubes

(CRT) technology is giving way to flat screen TV displays [3, 10], which in turn, gives rise to the following questions: What is the difference between these technologies? Are LCD TVs more efficient? Why is LCD most common in the consumer market? [3] In attempt to answer these questions in consonance with the following parameters; technology, aesthetic nature, portability and consumer market, it was discovered that,  Plasma based- and LCD based- TVs, respectively, have made tremendous impact than others. Major electronics stores have all but phased out the old CRT televisions, relegating them to the unseen corners [6].

Meanwhile, hordes of consumers are forced to make choices between two new technologies that they know little of. The objective of this research is to make comparative analyses of the three TV technologies that will provide the needed details to guide the consumers’ interest. The life-span of the three TV technologies will be compared, following the series of improvements recorded by the vendors.

1.2                                           BACKGROUND OF THE STUDY

Television (TV) is a widely used telecommunication  medium for transmitting and receiving moving images, either monochromatic (“black and white”) or color, usually accompanied by sound. “Television” may also refer specifically to a television set, television programming or television transmission. Commercially available since the late 1930s, the television set has become a common communications receiver in homes, businesses and institutions, particularly as a source of entertainment, tutorials and news. Since the 1970s the availability of video cassettes, laserdiscs, DVDs and now Blue-ray Discs, have resulted in the television set frequently being used for viewing recorded as well as broadcast material. A standard television set comprises multiple internal electronic circuits, including those for receiving and decoding broadcast signals. A television system may use different technical standards such as digital television (DTV) and high-definition television (HDTV). The different television technologies behind the CRT and the flat screen (LCD and Plasma) TVs continued to form a subject of comparison that consumers seem not to ignore especially when making a purchase.

A cathode ray tube is a vacuum tube which consists of one or more electron guns, possibly internal electrostatic deflection plates, and a phosphor target [13]. In television sets and computer monitors, the entire front area of the tube is scanned repetitively and systematically in a fixed pattern called a raster. An image 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 [14]. In all modern CRT monitors and televisions, the beams are bent by magnetic deflection, a varying magnetic field generated by coils and driven by electronic circuits around the neck of the tube, although electrostatic deflection is commonly used in oscilloscopes, a type of diagnostic instrument [14].

A liquid crystal display(LCD) is a flat panel display, electronic visual display, video display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly. They are used in a wide range of applications, including computer monitors, television, instrument panels, aircraft cockpit displays, signage, etc. They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. LCDs have displaced cathode ray tube (CRT) displays in most applications. They are usually more compact, lightweight, portable, less expensive, more reliable, and easier on the eyes. They are available in a wider range of screen sizes than CRT and plasma displays, and since they do not use phosphors, they cannot suffer image burn-in. LCDs are more energy efficient and offer safer disposal than CRTs. Its low electrical power consumption enables it to be used in battery-powered electronic equipment. It is an electronically modulated optical device made up of any number of segments filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in colour or monochrome. The most flexible ones use an array of small pixels. The earliest discovery leading to the development of

LCD technology, the discovery of liquid crystals, dates from 1888 [16]. By 2008, worldwide sales of televisions with LCD screens had surpassed the sale of CRT units.

1.3                                                     AIM OF THE STUDY

E-waste in these countries is rapidly increasing and monitor is one of the major contributors to it. The paper aims at assessing the life cycle environmental impact and functionality difference of Cathode Ray Tube (CRT), Liquid Crystal Display (LCD) and Light Emitting Diode (LED) monitors and their different functions that makes each one unique

1.4                                               OBJECTIVE OF THE STUDY

At the end of this study, consumers:

1. will found reasons for buying or using any technology of tv receiver
2. will understand the differences in all tv receiver technology

1.5                                           SIGNIFICANCE OF THE STUDY

This study was useful in assessing the life cycle environmental impact of Cathode Ray Tube (CRT), Liquid Crystal Display (LCD) and Light Emitting Diode (LED) monitors. Major benefit associated with each tv receiver technology and their power consumption during use phase are also studied.

1.6                                                   SCOPE OF THE STUDY

Recent advances in technology and the increased use of TV reciever for mobile health applications such as vision testing necessitate an understanding of the behavior of the displays of such devices, to facilitate the reproduction of existing or the development of new vision assessment tests. This study investigates the physical characteristics of one model of TV reciever with regard to display consistency across a set of devices (15) and their potential application.

The settings of the TV receivers adjusted prior to the measurements, for consistency of testing and to minimize power drain due to processor use. Autolock was set to “never,” auto-brightness was turned off, and brightness was set to its maximum setting of 100%. All applications running in the background were studied.