science

Large-screen television technology

Large-screen television technology is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Large-screen television technology rather than just read about it. In short: Large-screen television technology (colloquially big-screen TV) developed rapidly in the late 1990s and 2000s. Prior to the development of thin-screen technologies, rear-projection television was standard for larger displays, and jumbotron, a non-projection video display technology, was used at stadiums and concerts.

Key takeaways

Large-screen television technology belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Large-screen television technology to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Large-screen television technology from memory before moving on to harder problems.

Reference excerpt

Large-screen television technology (colloquially big-screen TV) developed rapidly in the late 1990s and 2000s. Prior to the development of thin-screen technologies, rear-projection television was standard for larger displays, and jumbotron, a non-projection video display technology, was used at stadiums and concerts. Various thin-screen technologies are being developed, but only liquid crystal display (LCD), plasma display (PDP) and Digital Light Processing (DLP) have been publicly released. Recent technologies like organic light-emitting diode (OLED) as well as not-yet-released technologies like surface-conduction electron-emitter display (SED) or field-emission display (FED) are in development to supersede earlier flat-screen technologies in picture quality. Large-screen technologies have almost completely displaced cathode-ray tubes (CRT) in television sales due to the necessary bulkiness of cathode ray tubes. The diagonal screen size of a CRT television is limited to about 100 cm (40 in) because of size requirements of the cathode-ray tube, which fires three beams of electrons onto the screen to create a viewable image. A large-screen TV requires a longer tube, making a large-screen CRT TV of about 130 to 200 cm (50 to 80 in) unrealistic. Newer large-screen televisions are comparably thinner.

Viewing distances

Before deciding on a particular display technology size, it is very important to determine from what distances it is going to be viewed. As the display size increases so does the ideal viewing distance. Bernard J. Lechner, while working for RCA, studied the best viewing distances for various conditions and derived the so-called Lechner distance. As a rule of thumb, the viewing distance should be roughly two to three times the screen size for standard definition (SD) displays.

Display specifications

The following are important factors for evaluating television displays:

Display size: the diagonal length of the display. Display resolution: the number of pixels in each dimension on a display. In general a higher resolution will yield a clearer, sharper image. Dot pitch: This is the size of an individual pixel, which includes the length of the subpixels and distances between subpixels. It can be measured as the horizontal or diagonal length of a pixel. A smaller dot pitch generally results in sharper images because there are more pixels in a given area. In the case of CRT displays, pixels are not equivalent to the phosphor dots, as they are to the pixel triads in LCDs. Projection displays that use three monochrome CRTs do not have a dot structure, so this specification does not apply. Response time: The time it takes for the display to respond to a given input. For an LCD it is defined as the total time it takes for a pixel to transition from black to white, and then white to black. A display with slow response times displaying moving pictures may result in blurring and distortion. Displays with fast response times can make better transitions in displaying moving objects without unwanted image artefacts. Brightness: The amount of light emitted from the display. It is sometimes synonymous with the term luminance, which is defined as the amount of light per area and is measured in SI units as candela per square meter. Contrast ratio: The ratio of the luminance of the brightest color to the luminance of the darkest color on the display. High contrast ratios are desirable but the method of measurement varies greatly. It can be measured with the display isolated from its environment or with the lighting of the room being accounted for. Static contrast ratio is measured on a static image at some instant in time. Dynamic contrast ratio is measured on the image over a period of time. Manufacturers can market either static or dynamic contrast ratio depending on which one is higher. Aspect ratio: The ratio of the display width to the display height. The aspect ratio of a traditional television is 4:3, which is being discontinued; the television industry is currently changing to the 16:9 ratio typically used by large-screen, high-definition televisions. Viewing angle: The maximum angle at which the display can be viewed with acceptable quality. The angle is measured from one direction to the opposite direction of the display, such that the maximum viewing angle is 180 degrees. Outside of this angle the viewer will see a distorted version of the image being displayed. The definition of what is acceptable quality for the image can be different among manufacturers and display types. Many manufacturers define this as the point at which the luminance is half of the maximum luminance. Some manufacturers define it based on contrast ratio and look at the angle at which a certain contrast ratio is realized. Color reproduction/gamut: The range of colors that the display can accurately represent.

Display technologies

LCD television

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Large-screen television technology

Start with the simplest possible case. Write down what Large-screen television technology claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Large-screen television technology before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Large-screen television technology ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Large-screen television technology

In research: Large-screen television technology appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Large-screen television technology in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Large-screen television technology is common in secondary-school and first-year university syllabi. It links to neighbouring topics Display technology, Television technology, so understanding it makes those chapters shorter.
In everyday life: Look for Large-screen television technology outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Large-screen television technology in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Large-screen television technology means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Large-screen television technology out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Large-screen television technology in simple terms?

Why does Large-screen television technology matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Large-screen television technology?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Large-screen television technology.