Free Essay

Lcd Principles and Applications

In: Science

Submitted By Manan777
Words 3870
Pages 16
Index:

|S. no. |Topic |Page no. |
|1 |Abstract |5 |
|2 |Introduction |6 |
|3 |Methodology |7 |
|4 |Liquid crystals |8 |
|5 |Working Principle and operation |9 |
|6 |Types of LCDs |12 |
|7 |Advantages of LCDs |13 |
|8 |Disadvantages of LCDs |14 |
|9 |Applications of LCDs |16 |
|10 |Discussions |19 |
|11 |Conclusions |20 |
|12 |References |21 |

Abstract:

Today we see items containing an LCD (liquid crystal display) everywhere. They are all around us -- in laptop computers, digital clocks and watches, microwave ovens, CD players and many other electronic devices. From the wrist watch and pocket calculator to an advanced VGA computer screen, the liquid crystal display has evolved into an important and versatile interface. A liquid crystal display consists of an array of tiny segments (called pixels) that can be manipulated to present information. This basic idea is common to all displays, ranging from simple calculators to a full color LCD television. The earliest discovery leading to the development of LCD technology, the discovery of liquid crystals, dates from 1888.Liquid crystals are technological materials whose molecular structure changes with the voltage applied. This allows for control of the amount of light passing through the crystal.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. With LCD technology it is possible to produce space-saving, flicker-free, low-radiation displays that are easier on the eyes than conventional television or computer monitors. In addition, liquid crystal displays have a sharper picture with greater contrast and they use less power.

Introduction:

Objective: The objective of my term paper is to review comprehensively the principle and the physic in the working of the Liquid Crystal Display and also assessing its advantages and disadvantages of in comparison to other display devices.

In the early 1970's, digital watches started showing up in the marketplace with a new and different type of display-the liquid crystal display or LCD.Liquid crystals were first discovered in the late 19th century by the Austrian botanist, Friedrich Reinitzer, and the term "liquid crystal" itself was coined shortly afterwards by German physicist, Otto Lehmann.

A liquid crystal display is a thin, flat electronic visual display that uses the light modulating properties of crystals. It is an electronically-modulated optical device made up of any number of pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome. Liquid crystal displays (LCDs) are a passive display technology. This means they do not emit light; instead, they use the ambient light in the environment. This has made LCDs the preferred technology whenever low power consumption and compact size are critical. The LCDs are over 1000 times more efficient at their job than the LEDs. LCD flat full color panels are now challenging the CRT as displays for television and computers. There are also many hybrid systems that use LCD display technology.

Methodology:

Thorough research was done before producing this term paper. Scholarly articles and books on the Liquid Crystal Display with particular focus on the physics behind its operation were reviewed. In addition, books and research papers on various display devices were consulted in order to asses the advantages as well as disadvantages of the LCD.The study examined the key concepts involved in the working of LCD and also its major applications.

Liquid crystals

There are 3 states of matter: solid, liquid, gas.
Solids states can be further categorized into: crystalline which has regular arrangement of molecules; and amorphous where there is no regular structure. In 1888, an intermediate phase was discovered and is known as the crystalline liquid or liquid crystal. This phase is called the nematic phase. For example, 4-n-pentyl-4'-cyano-biphenyl (PCB). Since than, over 20,000 known compounds have been found to have the nematic phase. [2]
The main interest in these types of compound is that the nematic phase compounds with rod-like molecules can be aligned by varying an external electric field. More specifically, they are a liquid with molecules oriented in one common direction (having a long range and repeating pattern).
Most liquid crystals are organic compounds consisting of long rod-like molecules which, in their natural state, arrange themselves with their long axes roughly parallel. It is possible to precisely control the alignment of these molecules by flowing the liquid crystal along a finely grooved surface. The alignment of the molecules follows the grooves, so if the grooves are exactly parallel, then the alignment of the molecules also becomes exactly parallel. [5] Most of the liquid crystal displays (LCDs) produced today uses either the twisted nematic (TN) or super twisted nematic (STN) electro-optical effects.

[pic] [pic]

Principle of LCD

LCDs are light valves. The principle of the liquid crystal display's operation is radically different from all other display devices. LCDs are light modifiers, not light producers. All the other devices are self-illuminating as they produce their own light. The LCD does not make its own light, but operates by modifying light from other sources. This distinction is very important and is responsible for the low power consumption of the LCD. The external light modified by the LCD may be ambient light or a special light source installed within the device just to supply the LCD some light to modify. LCDs use a reflector, backlight, sidelight, or a combination of a reflector and back/sidelight to display an image. Since most of special light source come from the back of the LCD Panel, hence it is commonly known as back-lit LCD.[1]

Inside a LCD, there are two thin plates of glass with a special liquid crystal solution between them. This liquid crystal solution has an interesting property. If there is no current going through the liquid crystal solution, the solution is clear. But when there is an electrical current going through the solution, the solution crystallizes and goes from clear to dark. The solution acts like a shutter when current is passed through it, changing from clear to dark.

[pic]

OPERATION OF LCD

The combination of four facts makes LCDs possible:

• Light can be polarized. • Liquid crystals can transmit and change polarized light. • The structure of liquid crystals can be changed by electric current. • There are transparent substances that can conduct electricity.

An LCD is a device that uses these four facts in a surprising way.

In their natural state, LCD molecules are arranged in a loosely ordered fashion with their long axes parallel. However, when they come into contact with a grooved surface in a fixed direction, they line up in parallel along the grooves. The first principle of an LCD consists of sandwiching liquid crystals between two finely grooved surfaces, where the grooves on one surface are perpendicular (at 90 degrees) to the grooves on the other. If the molecules at one surface are aligned north to south, and the molecules on the other are aligned east to west, then those in-between are forced into a twisted state of 90 degrees. Light follows the alignment of the molecules, and therefore is also twisted through 90 degrees as it passes through the liquid crystals. However, following RCA America's discovery, when a voltage is applied to the liquid crystal, the molecules rearrange themselves vertically, allowing light to pass through untwisted.
The second principle of an LCD relies on the properties of polarising filters and light itself. Natural light waves are orientated at random angles. A polarising filter is simply a set of incredibly fine parallel lines. These lines act like a net, blocking all light waves apart from those (coincidentally) orientated parallel to the lines. A second polarising filter with lines arranged perpendicular (at 90 degrees) to the first would therefore totally block this already polarised light. Light would only pass through the second polarizer if its lines were exactly parallel with the first, or if the light itself had been twisted to match the second polarizer. A typical twisted nematic (TN) liquid crystal display consists of two polarising filters with their lines arranged perpendicular (at 90 degrees) to each other, which, as described above, would block all light trying to pass through. But in-between these polarisers are the twisted liquid crystals. Therefore light is polarised by the first filter, twisted through 90 degrees by the liquid crystals, finally allowing it to completely pass through the second polarising filter. However, when an electrical voltage is applied across the liquid crystal, the molecules realign vertically, allowing the light to pass through untwisted but to be blocked by the second polariser. Consequently, no voltage equals light passing through, while applied voltage equals no light emerging at the other end.
[pic]
The crystals in an LCD could be alternatively arranged so that light passed when there was a voltage, and not passed when there was no voltage. However, since computer screens with graphical interfaces are almost always lit up, power is saved by arranging the crystals in the no-voltage-equals-light-passing configuration. An important feature of an LCD monitor is its response time, which is the time it takes for an applied voltage to effect the liquid crystals' alignment and register a change to the screen. This is a value measured in milliseconds (ms), and clearly the lower the value the better for the screen.
Colors of LCDs:

In color LCDs each individual pixel is divided into three cells, or sub pixels, which are colored red, green, and blue, respectively, by additional filters (pigment filters, dye filters and metal oxide filters). Each sub pixel can be controlled independently to yield thousands or millions of possible colors for each pixel through the careful control and variation of the voltage applied; the intensity of each sub pixel can range over 256 shades. Combining the sub pixels produces a possible palette of 16.8 million colors (256 shades of red x 256 shades of green x 256 shades of blue). Color displays take an enormous number of transistors.

[pic]
Types of LCDs:

There are 2 types of Liquid crystal displays, namely active and passive.

Passive Matrix:

In a passive matrix, or FSTN, display a grid of electronic control wires or lines are placed on the front and back glass. A pixel is located at the junction of each row and column control lines. Passive matrix displays use one transistor to address each row and one to address each column of pixels. Pixels are turned on when both row and column lines are energized and off when both control lines are de-energized. This addressing scheme is called multiplexing. The residual electrical current that travels down each control line can cause crosstalk at unselected pixels. [8] Crosstalk partially darkens pixels and lowers the display's overall contrast. This usually appears on a passive matrix PowerBook display as two dark boxes, parallel to each other on the display.

Active Matrix:

The active matrix or Thin-Film Transistor (TFT) display is the latest technology used in computers. Rather than using multiplexing (row and column wires on the glass) techniques to address the matrix of crystals, the active matrix LCD includes a transistor fabricated along with each pixel. Because of the transistors, pixels can be turned on and off at a very fast rate. The transistor at each pixel eliminates the crosstalk phenomenon, which lowers contrast on the passive matrix display. The TFT method eliminates the time dependency associated with multiplexed displays by directly addressing each pixel. Active LCD's can show colors other than black and white. This is due to the pixels that make up a computer monitor, digital clock faces, and other liquid crystal displays. In active LCDs, each of these little pixels can be programmed individually to display color.

However, in passive LCDs only entire lines of pixels can be programmed. So, passive LCDs are not made to display colors. Active matrix has a much wider viewing range than passive matrix. Information displayed on the screen can be seen from a wider side angle on an active matrix display than on a passive matrix display.

Advantages of LCDs:

LCDs have various advantages which make them one of the most widely used display techniques. They are not only lightweight, small in size and compact but are also energy efficient. Because LCDs consist of only two thin plates of glass, they are small enough to fit anywhere. Some of the major advantages of a Liquid Crystal Display are as follows:

1.Sharpness:
The image is perfectly sharp at the native resolution of the panel. LCDs using an analog input require careful adjustment of pixel tracking/phase.

2.Power Consumption :
Energy efficient. Consume less than 1/3 the power of a comparable CRT. Consume less electricity than a CRT and produce little heat.

3.Brightness:
Produces very bright images due to high peak intensity. Very suitable for environments that are brightly lit.

4.Screen Shape:
Screens are perfectly flat.

5.Physical:
Thin and compact. Consume little electricity and produce little heat. LCDs take up about 40% less desk space.

6.Emissions: Produce considerably lower electric, magnetic and electromagnetic fields than CRTs.

7.Geometric Distortion:
Zero geometric distortion at the native resolution of the panel. Minor distortion for other resolutions because the images must be rescaled.

There are no convergence problems with an LCD panel, because each cell is switched on and off individually whereas a CRT has three electron guns whose streams must converge faultlessly in order to create a sharp image.
Disadvantages of LCDs:

Although LCDs are extremely useful, they also have some disadvantages and problems.
1.Resolution (The horizontal and vertical screen size expressed in pixels).Each panel has a fixed pixel resolution format determined at the time of manufacture that can not be changed. All other image resolutions require rescaling, which generally results in significant image degradation, particularly for fine text and graphics. It works well only at the native resolution.
2.Interference :LCDs using an analog input require careful adjustment of pixel tracking/phase in order to reduce or eliminate digital noise in the image. Automatic pixel tracking/phase controls seldom produce the optimum setting. Timing drift and jitter may require frequent readjustments during the day. For some displays and video boards its not possible to entirely eliminate the digital noise.
3.Viewing Angle :It has a limited viewing angle. Brightness, contrast, gamma and color mixtures vary with the viewing angle. Can lead to contrast and color reversal at large angles. Need to be viewed as close to straight ahead as possible. [4]
4. Black-Level, Contrast and Color Saturation: LCDs have difficulty producing black and very dark grays. As a result they generally have lower contrast than CRTs and the color saturation for low intensity colors is also reduced. Not suitable for use in dimly lit and dark environments.
5. White Saturation: The bright-end of the LCD intensity scale is easily overloaded, which leads to saturation and compression. When this happens the maximum brightness occurs before reaching the peak of the gray-scale or the brightness increases slowly near the maximum. It requires careful adjustment of the Contrast control.
6. Color and Gray-Scale Accuracy :The internal Gamma and gray-scale of an LCD is very irregular. LCDs typically produce fewer than 256 discrete intensity levels. For some LCDs portions of the gray-scale may be dithered. Images are pleasing but not accurate because of problems with black-level, gray-scale and Gamma, which affects the accuracy of the gray-scale and color mixtures. Hence, they are generally not suitable for professional image color balancing.
7. Bad Pixels and Screen Uniformity :LCDs can have many weak or stuck pixels, which are permanently on or off. Some pixels may be improperly connected to adjoining pixels, rows or columns. Also, the panel may not be uniformly illuminated by the backlight resulting in uneven intensity and shading over the screen.
8. Motion Artifacts: Slow response times and scan rate conversion result in severe motion artifacts and image degradation for moving or rapidly changing images.
9. Aspect Ratio :LCDs have a fixed resolution and aspect ratio (The ratio of the width to the height). For panels with a resolution of 1280x1024 the aspect ratio is 5:4=1.25, which is noticeably smaller than the 4:3=1.33 aspect ratio for almost all other standard display modes.
10. Cost :Considerably more expensive than comparable CRTs.
The liquid crystals used for display technology are thermotropic liquid crystals; they exhibit desired characteristics over a specific temperature range. Thus LCDs do not operate properly when they are too cold or too warm. If liquid crystals are too cold, they will not twist and the display will not form an image. If the display is too warm, the resistance of the liquid crystal material changes and this alters the properties of the display and performance suffers

However, with today's rate of technological innovation, these problems will probably soon be solved, making LCDs even more dominating in display technology.

Applications of liquid crystal technology:
Liquid crystal technology has had a major effect many areas of science and engineering, as well as device technology. Applications for this special kind of material are still being discovered and continue to provide effective solutions to many different problems. The LCD was commercialized in 1960's for use in calculators and wristwatches, but is now most commonly found in notebook PCs. LCDs have also expanded into desktop monitors along with other innovative and exciting digital applications In the future, the TFT-LCD will emerge as the most widely used display solution, because of its high reliability, viewing quality and performance, compact size and environment-friendly features. Various devices use LCD such as:

Microwaves and ovens

VGA computer screens and laptops

Television screens

Digital watches and clocks

Pocket calculators

Monitors for medical equipment

Car navigation and entertainment systems

CD players

Avionics instrumentation.

However, its major use is seen in the following fields:

A) Thin Film Transistor (TFT) ▪ Constructed on a glass surface using a photolithographic process. ▪ The source and gate are the control electrodes. The drain electrode connects to the liquid crystal pixel. The thin layer of amorphous silicon is the semiconducting material that allows the TFT to function. The capacitor is attached to the pixel electrode, but is not an integral part of the TFT.[7]

[pic]

B) Alpha-numeric display ▪ Digital letters can be displayed by blocking the lights in different plates we place. ▪ For applications such as digital watches and calculators, a mirror is used under the bottom polarizer. With no voltage applied, ambient light passes through the cell, reflects off the mirror, reverses its path, and re-emerges from the top of the cell, giving it a silvery appearance. ▪ When the electric field is on, the aligned LC molecules do not affect the polarization of the light. The analyzer prevents the incident light from reaching the mirror and no light is reflected, causing the cell to be dark. When the electrodes are shaped in the form of segments of numbers and letters they can be turned on and off to form an alpha-numeric display.

[pic] [pic]

C) Back lighting systems ▪ Alpha-numeric displays are not very bright because the light must pass through multiple polarizer which severely cut down on the intensity of the light, in addition to the various layers of the display which are only semi-transparent. Therefore a more intense source is employed in the form of a back lighting system.

For brighter displays ▪ Light bulbs mounted behind ▪ At the edges of the display replace the reflected ambient light. ▪ Disadvantage: very power intensive. Back lighting systems are used in more complex displays such as laptop computer screens, monitors, LCD projectors, pda, digital devices such as digital camera and DV.[3]

Future technology developments in the military and in aerospace sectors will also fuel the growth for the TFT-LCD market.
[pic]

Discussions:

Liquid Crystal Displays, or LCDs, are quickly becoming the display technology of choice. This simple but extremely useful invention is being used in almost everything we can think of. From the displays of digital watches, to calculators and even computer monitors, LCD's provide a way to display information in a more effective way than we ever could before. The LCD displays used in the early digital watches were very different from the LEDs they replaced. While even a tiny LED display consumes a few mill watts of power, the LCD consumes just microwatts of power. Unlike LED displays, which are usually quite small, LCDs can be fabricated in almost any convenient size. Hence, the LCDs are over 1000 times more efficient at their job than the LEDs.
Since its advent in 1971 as a display medium, liquid crystal displays have moved into a variety of fields, including miniature televisions, digital still and video cameras and monitors and today many believe that the LCD is the most likely technology to replace the CRT monitor. The technology involved has been developed considerably since its inception, to the point where today's products no longer resemble the clumsy, monochrome devices of old.

Conclusions:

The Liquid Crystal Display technology is one of the most popular and widely used display technology at present. A Liquid crystal cell consists of a thin layer of liquid crystal sandwiched between two glass sheets with transparent electrodes deposited on their inside faces.LCDs are categorized as non- emissive display devices. In an LCD, an electric current is used to switch segments of liquid crystals from a transparent phase to a cloudy phase, each segment forming part of a number or letter. The segments can also be in the shape of tiny dots or pixels, and the can be arranged in rows and columns. They are turned on and off individually to either block or allow polarized light to pass through. When the light is blocked, a dark spot is created on the reflecting screen.LCDs are used most frequently to display one or more lines of alpha-numeric information in a variety of devices: fax machines, laptop computer screens, answering machine call counters, scientific instruments, portable compact disc players, clocks, and so forth. The most expensive and advanced type—active matrix displays—are even being used as screens for handheld color TVs.
Hence, I would like to conclude that LCDs have a head start over other flat screen technologies and an apparently unassailable position in notebook, handheld PCs and many other devices.

References:

[1] Joseph A Castellano. (2005) Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry .World Scientific Pub Co Inc.

[2] Birendra Bahadur. Liquid Crystals-applications and uses. North-Holland/Elsevier Science

[3] Miriam A. Drake. (2003) Encyclopedia of library and information science.

[4] Mohammad A. Karim. (1992) Electro-optical displays. PWS KENT Publishing Co, Boston,

[5] Peter J.Collings. (2001) Liquid Crystals Princeton University Press.

[6] Encyclopaedia Britannica. 2010. Encyclopaedia Britannica Online. 20 June. 2010 .

[7] T.J Nelson, J R Wullert. Electronic Information Display technologies. (Bell Communications Res. Inc., USA)

[8] Willem den Boer. (2005) Active matrix Liquid Crystal Display-edition-1.Publisher: Newnes.

[9] Ronald G. Driggers. (2003) Encyclopedia of Optical Engineering. Publisher: Crc Press…...

Similar Documents

Premium Essay

Lcd Monitor

...as ERS transaction issues, provisioning issues, VAS activation/deactivation, execution of blocking/restoration/termination as per subscriber request, installation of a wide array of services etc. ϖ The main objective is to plan a marketing strategy for developing sales Job Description: ➢ I started my career as a team member and was promoted to a supervisor & Assistant manager. My duties to pass evaluation and updating promotion, collecting daily figures, fixing new promotion, daily job allotment to the service and handling the human resources and helping to the manager in all aspect Computer Skill o Operating System : Microsoft Windows XP & Vista o Applications : MS Word, MS PowerPoint, MS Excel. o Internet : All Kinds of Operation & E-Mail EDUCATIONAL BACKGROUND 1. Qualification : Masters of Business Study(MBS) Major : Accounting Institute/University : National University (kobi Nazrul Government Collage) Resul : 2nd Division Passing year : 2007 2. Qualification :Bachelor of Business Study (BBS) Major : Management. Institute/University : National University (kobi Nazrul Government Collage) Resul : 2nd Division Passing year : 2006 3. Qualification : Higher Secondary Certificate (HSC). Field of Study : Business Studies / Commerce. Institute/University : BAF Shaheen College, Tejgaon. Result : 2nd Division. Passing......

Words: 682 - Pages: 3

Free Essay

Lcd Display

... REG NO. :- 11013455 LIQUID CRYSTAL DISPLAY TABLE OF CONTENTS |SNO |TOPIC |PAGE | | | |NO | |1 |what is lcd | 8 | |2 |Technology behind lcd |9 | | |monitor | | |3 |Working of lcd monitor |10 | |4 |Features of lcd television |11 | |5 |Diff between lcd and plasma|12 | |6 |Texas instrument’s test |14 | |7 |High transmissive tft lcd |16 | | |technology | | |8 |Challenging technologies |19 | | |for lcd | | |9 |Conclusion | | |10 |Refrences | | | | | | | | | | | | | ......

Words: 6534 - Pages: 27

Free Essay

Deploying Application Firewall in Defense in Depth Principle

...Deploying Application Firewall in Defense in Depth Principle Abstract Information security should be a priority for businesses, especially when they are increasingly involved in electronic commerce. With the understanding that securing an operating system successfully requires taking a systematic and comprehensive approach, security practitioners have recommended a layered approach called defense-in-depth. The cost and complexity of deploying multiple security technologies has prevented many organizations from achieving their information security goal. In view of these constraints and in compliance with recent with recent corporate and industry regulations like Sarbanes-Oxley Act and Payment Card Industry Data Security Standard, businesses now deploy application firewalls as security measures. Based on the foregoing, the author has recommended the use of application firewalls as a single platform for achieving layered security through network protection, application protection and data protection. This paper commences by examining the defense in depth theory and the types of application firewall and the author concludes by citing the Institute for Computing Applications (IAC) of the Italian National Research Council (CNR) as an example of an organization which engaged application firewalls in resolving its network security problem. Research Analysis/ Body The development of Information security is of paramount importance to organizations that have online......

Words: 1701 - Pages: 7

Free Essay

Lcd Screens

...LCD Screens LCDs (liquid crystal display) are used in a wide range of products, from watches and digital clocks, to microwaves and laptop computers. Now what has made this technology so popular amongst consumers over the years , is the fact that they offer great advantages as compared to other display systems. Such as their lighter and thinner nature, as well as the ability to use less amounts of power. Now at first, the very name “liquid crystal” sounds a bit contradictory. How can any material be both a solid and a liquid? This is explained by the fact that the crystals in the LCD exist in a kind of a distinct middle ground between a solid form and liquid form, which gives them the movement and flexibility of a liquid, but can also let them remain in their place like a solid. So, technically they are not just one or the other. Furthermore, there are a large variety of liquid crystal substances, which can exist in many different phases, depending on the temperature and nature of that substance. The most important being the nematic phase, which is what makes LCDs possible. In the nematic phase, the liquid crystals are affected by electric currents, so in an LCD screen, those currents work at a microscopic level to control the amount of light that passes through the liquid crystal molecules that make up the moving layer of the screen, which is then placed in between clear glass panels. These currents also force the molecules (which are naturally twisted) to unwind or...

Words: 643 - Pages: 3

Free Essay

Nokia Lcd

...pixels matrix LCD controller/driver Product specification File under Integrated Circuits, IC17 1999 Apr 12 Philips Semiconductors Product specification 48 × 84 pixels matrix LCD controller/driver CONTENTS 1 2 3 4 5 6 6.1 6.1.1 6.1.2 6.1.3 6.1.4 6.1.5 6.1.6 6.1.7 6.1.8 6.1.9 6.1.10 6.1.11 6.1.12 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.7.1 7.8 FEATURES GENERAL DESCRIPTION APPLICATIONS ORDERING INFORMATION BLOCK DIAGRAM PINNING Pin functions R0 to R47 row driver outputs C0 to C83 column driver outputs VSS1, VSS2: negative power supply rails VDD1, VDD2: positive power supply rails VLCD1, VLCD2: LCD power supply T1, T2, T3 and T4: test pads SDIN: serial data line SCLK: serial clock line D/C: mode select SCE: chip enable OSC: oscillator RES: reset FUNCTIONAL DESCRIPTION Oscillator Address Counter (AC) Display Data RAM (DDRAM) Timing generator Display address counter LCD row and column drivers Addressing Data structure Temperature compensation 8 8.1 8.2 8.3 8.3.1 8.3.2 8.3.3 8.4 8.4.1 8.5 8.6 8.7 8.8 8.9 9 10 11 12 12.1 12.2 13 14 14.1 14.2 15 16 17 INSTRUCTIONS Initialization Reset function Function set Bit PD Bit V Bit H Display control Bits D and E Set Y address of RAM Set X address of RAM Temperature control Bias value Set VOP value LIMITING VALUES HANDLING DC CHARACTERISTICS AC CHARACTERISTICS Serial interface Reset PCD8544 APPLICATION INFORMATION BONDING PAD LOCATIONS Bonding pad information Bonding pad location TRAY INFORMATION DEFINITIONS LIFE SUPPORT......

Words: 7665 - Pages: 31

Free Essay

Lcd Alphanumeric

...LCD The most commonly used LCDs found in the market today are 1 Line, 2 Line or 4 Line LCDs which have only one controller and support at most 80 characters, whereas LCDs supporting more than 80 characters make use of 2 HD44780 controllers. Apart from displaying some simple static characters you can create animated text scripts and a lot more! Let’s start playing with them, but you will have to wait a little as these things mentioned below will help you to create your own magical codes. Most LCDs with 1 controller has 14 Pins and 16 Pins (two extra pins are for back-light LED connections). Pin description is shown in the table below. (We may also have 16 pins in 2 controllers, refer to the datasheet for exact details). This may not match with the exact pin configuration for your LCD, check application circuit in datasheet for exact configuration. We will discuss here 8 bit mode first (that is data transfer through all the 8 data pins), 4 bit mode will be discussed later on. Read/Write (RW): 1.) RW= 0, the information is being written on LCD. 2.) RW=1, for reading from LCD. (Only one command that is “Get LCD status” is a read command all others are write command) It is a control line. When RW is low (0), the information on the data bus is being written to the LCD. When RW is high (1), the program is effectively querying (or reading from) the LCD. Only one instruction ("Get LCD status") is a read command. All others are write commands--so RW will be low for majority......

Words: 663 - Pages: 3

Premium Essay

Marketing Principles and Applications

...Devil – Vacuum Cleaners Cytonia Williams 000299566 Marketing Principles and Applications Western Governors University Abstract Company G new stream of vacuum cleaners – “Devil”, are a part of newly improved line of small appliances. The vacuum cleaners are designed in way, so that they allow consumers to improve the quality and convenience of their lives. These new lines of vacuum cleaners are very effective which deliver unmatchable performance by any existing product in the market. Company G’s vacuum cleaners are targeted for consumers who are pet owners. Devil product line will use the existing company logo XG on the product. As an introductory offer company G is offering a 30-day money back with no questions asked to the customers. Product Support of Mission Statement Company G’s Devil vacuum cleaner is a high-quality, innovative electronic solution to enable consumers to improve the quality and convenience of their lives. Devil vacuum cleaner line falls into the category of shopping goods (Consumer good classification).Devil vacuum is part of re-designed small appliances category. The re-designed vacuum cleaner provides a superior performance over any available product in this line. Company G’s engineers were able to design the product in such a way that these appliance provided effective and stable performance for years. This has added lot of value to the Devil product line. Target Market Most pet owners face with pet hair problems and most current vacuum......

Words: 1833 - Pages: 8

Premium Essay

Lcd Display

...VI. CONCLUSIONS    Without doubt, Gi-Fi wireless technology represents a considerable improvement if compared to the existing technology. The new technology provides innumerable features that improve both the overall functionality as well as some specific security functions. Thus we conclude by all above gaining information that Gi-Fi wireless technology is advance in many matter by the existing wireless technology. GiFi technology is defined that will allow wireless transfer of audio and video data up to 5 gigabits per second, ten times the current maximum wireless transfer rate, at one-tenth of the cost, usually within a range of 10 meters that operates at 60GHz on the CMOS process. This technology removes cables that for many V. APPLICATION OF GI-FI If all the computers in your house are connected to a Gi-Fi network, you can easily connect your smart phone to the same network and control them. Consumers could typically download a high definition movie from a kiosk in a matter of seconds to music player or smart phone and having got home could play it on a home theatre system or store years curled the world and provides high speed data transfer rate. Finally, I would like to state that even though Gi-Fi wireless network technology have a huge potential we will only get the best of them . REFERENCES [1] Marzieh yazdanipour , Afsaneh Yazdanipour , Amin Mehdipour and Mina Yazdanipour “Evaluation of Gi-Fi Technology for Short-Range” UACEE International Journal......

Words: 1846 - Pages: 8

Premium Essay

Increasing Application of Scientific Management Principles

...Increasing application of Scientific Management principles 'The increasing application of Scientific Management principles of work organisations to services is, despite its limitations, inevitable and irreversible'. Discuss. I Introduction From the outset of this essay it is necessary to define the basic principles of Scientific Management in order for the statement to be fully understood and why if at all such a practice is 'inevitable' and indeed 'irreversible' within a service industry context. The underlying belief that scientific management, or rationalisation= , is able to provide the basis for separating management from the execution of work. 'The rationalisation of work has the effect of transferring functions of planning, allocation and co-ordination to managers, whilst reinforcing the managerial monopoly of decision-making, motivation and control'. Hales (1994). Taylor (1856-1915) has been referred to as the father of Scientific Management. He believed that management, not labour, was the cause of and potential solution to problems in the industry. Taylor concluded that workers systematically 'soldiered' because they believed that faster work would put them out of a job and because hourly or daily wages destroyed individual incentive. Taylor believed that in order to discourage, and indeed halt, this 'soldiering' a 'mental revolution' was required. He believed this could be achieved via four vital principles: (1) the development of the best work method,...

Words: 415 - Pages: 2

Free Essay

Principles and Applications of Organic Solar Cells

...有机太阳能电池原理与应用 何游 刘世卓 许德安 张昱 (South University of Science and Technology of China) 摘要: 有机半导体材料以其原料易得,廉价,制备 工艺简单,环境稳定性高,可折叠,有良好的光 伏效应等优点,日益被人们所重视。本文首先介 绍了有机太阳能电池的分类、结构及基本原理, 之后评述了有机太阳能电池的应用,并对它的未 来发展前景作了展望。 1.引言 1.1 有机太阳能电池背景 随着煤炭、石油、天然气等化石燃料的大量使用,对全球环境造成了不可忽视的污 染,排放二氧化碳、甲烷等温室气体也造成了全球气候变化,更加棘手的是上述等不可 再生能源的数量是有限的,随着时间的推移和消耗量的剧增,能源危机成为人类不得不 面对的严峻问题之一。 而太阳能是取之不尽用之不竭的绿色新能源, 太阳能的广泛应用为能源问题带来一 丝曙光。利用太阳能必须依赖于光伏电池,而有机光伏电池又是其中很重要的一部分。 本文将针对有机太阳能电池的分类、结构、原理、局限以及发展前景展开评论。 太阳能电池又称为“太阳能芯片”或“光电池” “,是一种利用太阳光直接发电的 光电半导体薄片。它只要被光照到,瞬间就可输出电压及电流。在物理学上称为太阳能 光伏(Photovoltaic,photo 光,voltaic 伏特,缩写为 PV) ,简称光伏。 1839 年, 1883 年 Charles 光生伏打效应第一次由法国物理学家 A.E.Becquerel 发现。 Fritts 制造了第一块太阳电池。Charles 用硒半导体上覆上一层极薄的金层形成半导体金 属结,该器件只有 1%的效率。1970 年代,由于能源危机,世界各国开始关注能源开发 1973 年发生了石油危机, 的重要性。 人们开始把太阳能电池的应用转移到一般的民生用 途上。 1.2 有机太阳能电池分类 1.2.1 单层有机太阳能电池 单层有机太阳能电池是有机太阳能电池中最简单的形式, 两个金属导电层夹着有机 电子材料层,例如高功函的氧化铟锡(ITO)和低功函的铝、镁和钙。 两个导电层的功函差在有机层的两端建立了一个电场。当有机层吸收小光子后, 电 子会被激发到 LUMO 上,空穴留在 HOMO 上形成激子,而电极上不同的功函造成的电 势有利于激子的分离,将电子拉到正极,空穴拉到负极,这个过程中形成的电压和电流 就可以被利用。电场并不是最好的使激子分离的方法,异质结电池中使用有效场来使激 子分离的效率更高。 1.2.2 双层太阳能电池 这类电池在电极间有两层不同的物质,这两种物质在电子亲和性、电离能方面有差 异,因此静电力在两层间的界面产生。这两层所用的材料要尽可能使这两种差异更大, 从而使得局部电场大到足以使激子分离,比单层太阳能电池更有效。两种材料中拥有较 高电子亲和性和电离能的是电子受体,另外一个是电子给体。这种结构也叫做平面给受 异质结。 1.2.3 本体异质结太阳能电池 在本体异质结太阳能电池中,电子给体与受体共混到一起形成膜。每块给体或受体 的长度与激子扩散距离一致,给体或受体中产生的大部分激子可以到达两个物质的界 面,并得到有效的分离。电子迁移到受体区域后逐渐到达电极并被收集,空穴被拉到相 反的方向,并被另一个电极所收集。 2.有机光伏电池结构 2.1 有机光伏电池原理 太阳能电池是一个特别的半导体二极管,它可能将可见光能转化为直流电,一些 太阳能电池可能转化红外和紫外光的能量为直流电。 通常用于有机光伏电池的材料都是......

Words: 680 - Pages: 3

Free Essay

Lcd Industy

...LCD 구동기술 및 개발 현황 권 오 경 LCD는 Liquid Crystal Display의 약어를 말하며, 1888년 오스트리아의 F. Reinitzer에 의해 처음 발견된 액정(Liquid 편광판, 상판과 하판의 편광방향을 90도로 배치하게 되면, 액정이 없을 경우 빛이 통과하지 못하게 된다. 액정의 역할은 상판과 하판 사이에서 투과하는 빛을 회전시켜 패널을 통과 하게 만들어 준다. 양단에 전압을 걸어주게 되면 그림 2와 같 이 누워있는 액정이 일어서게 된다. 빛의 방향과 평행하게 되 면 액정의 이방성이 사라져서 빛이 회전시키지 못하므로 액 정이 없는 것과 같이 빛이 통과하지 못하게 된다. 전압을 이 용하여 액정 분자 배열의 기울기를 조절하게 되는데, 편광판 과 액정 사이의 각도에 따라 상판과 하판 사이에서 빛의 회 전 각도가 달라진다. 또한 액정에서 빛을 회전시키는 각도에 따라 투과율이 달라진다. 즉 전압을 이용하여 빛의 투과율을 조절할 수 있다. 액정 양단에 전압을 걸어주지 않았을 경우 에, 그림 2와 같이 빛을 모두 통과시켜 밝은 빛이 나오면 정 상 화이트 모드(normally white mode)라고 하고, 그림 3과 Crystal)은 1968년 미국 RCA사에 의해 디스플레이에 응용됐 다. 1973년에 전자계산기, 전자시계에 적용된 액정은 1986 년 이후 STN LCD(super twisted nematic LCD)와 소형 TFT LCD(thin film transistor LCD)가 실용화됐다. 1990년 대 들어 10인치 TFT LCD의 양산화가 실현되면서 노트북PC 의 대표적인 디스플레이로 자리 잡고 CRT를 대체하는 디스 플레이 중 하나로 각광받고 있다. 현재는 소형부터 대형에 이 르기까지 모든 디스플레이에서 TFT-LCD가 주로 사용되며 계 속해서 급속한 성장을 이루고 있다. 따라서 본 원고에서는 가 장 널리 사용되고 있는 LCD, 특히 TFT-LCD에 대한 이해를 향상시키기 위해서 TFT-LCD의 기본 동작원리와 구동 기술에 대해 기술하고, 이를 바탕으로 현재까지 개발된 LCD 구동 기 술에 대하여 서술한다. LCD의 구조 및 동작 원리 LCD 구동방식에는 능동방식(AM: active matrix)과 수동방 식(PM: passive matrix)이 있다. 수동방식 LCD에 주로 사용 되는 STN LCD는 고해상도와 고계조의 표현이 어렵기 때문 에, 대부분의 LCD 디스플레이 장치는 TFT를 이용하는 능동 방식이 적용되어 있다. 능동 방식의 LCD에서는 STN 액정의 응답속도가 느리기 때문에, 응답속도가 빠르고, 그림 1에서처 럼 계조 표시가 쉬운 TN(twisted nematic) 액정을 사용한다. 유도 분극현상 때문에 전압을 걸어주면 액정 분자 배열의 기울기가 달라지는데 이것을 이용하여, 빛의 투과율을 조절한 다. 자연광과 같은 경우 모든 방향으로 진동하는 빛으로는, 투과율을 조절할 수 없다. 그래서 액정의 양쪽에 편광판을 배 치하여 일정한 방향으로 진동하는 빛만......

Words: 595 - Pages: 3

Premium Essay

Beximco Group Mis Application of Henri Fayol's 14 Principles of Management

...BRAC University Summer'2013 BEXIMCO Group MIS Application Of Henri Fayol's 14 Principles of Management BEXIMCO Group MIS- Application of Henri Fayol's 14 Principles of Management Submitted to: Afsana Akhtar Assistant Professor BRAC Business School BRAC University Date of Submission: 13th August, 2013 LETTER OF TRANSMITTAL 13th August, 2013 To, Afsana Akhtar Assistant Professor BRAC Business School BRAC University. Sub: Submission of term paper for completion of course. Dear Madam, With high reverence we want to state that we have finished our term paper on the application of Henri Fayol's 14 Principles of Management in Beximco Group MIS in Bangladesh. While working with the term paper we got the first hand experience to learn about the applied management techniques in an organization. It helped us in gaining a new point of view on the significance of management theory like Henri Fayol's 14 Principles plays a role in effective and efficient performance of organizations such as Beximco Group MIS. We did some elaborate research and interviews and came up with sufficient resources to compile our term paper in a comprehensive manner. This term paper is valuable and a necessity to complete our course MGT211. In this term paper, all the team members contributed equally with sheer hard work. We faced some challenges in working as a team but due to everyone's collective efforts we overcame them and tried to produce this paper for......

Words: 12245 - Pages: 49

Premium Essay

Application of Lean and Jit Principles in Supply Chain Management

... Int. J. Mgmt Res. & Bus. Strat. 2013 Jaskanwal Singh Mand et al., 2013 ISSN 2319-345X www.ijmrbs.com Vol. 2, No. 1, January 2013 © 2013 IJMRBS. All Rights Reserved APPLICATION OF LEAN AND JIT PRINCIPLES IN SUPPLY CHAIN MANAGEMENT Chandan Deep Singh1, Rajdeep Singh1, Jaskanwal Singh Mand1* and Sukhvir Singh1 *Corresponding Author: Jaskanwal Singh Mand,  mandjaskanwal@yahoo.com Supply Chain Management is a set of synchronized decisions and activities utilized to efficiently integrate suppliers, manufacturers, warehouses, transporters, retailers, and customers so that the right product or service is distributed at the right quantities, to the right locations, and at the right time, in order to minimize system-wide costs while satisfying customer service level requirements. SCM leads to a proficient way of doing things completely. Lean manufacturing and JIT play an importunate role in better functioning of SCM. Some of the lean manufacturing principles are: JIT inventory principle, JIT production principle, JIT human resource principle, JIT quality principle, JIT supplier relation principle, The present research involves role of lean manufacturing and JIT principles in SCM. Keywords: SCM, JIT, Lean manufacturing origin of the concept of lean or lean thinking cannot be easily assigned to any one person, company, INTRODUCTION Supply Chain Management (SCM) is a set of synchronized decisions and activities utilized to efficiently integrate......

Words: 6899 - Pages: 28

Premium Essay

Principles/Applications of Adul Learning

...Abstract We all agree in the assessment of our education and learning experiences, in that we have put our goals in order so that we know what is expected of us from the very start and what opportunities are available to us through feedback, honesty, and encouragement. We have learned from our mistakes and have taken notes to prevent ourselves from making the same mistakes twice. We believe that orderliness is what has helped in our learning abilities. As we make mistakes, we have learned the right ways to get things done and not repeat them. We have more patience with others and ourselves and in our differences. Our learning experiences have made us better people. Here is a list of our fundamental changes that we have redefined education and learning with regards to our personal, social and work values. Personal Values 1. We have learned to relax and enjoy life. 2. We have made education a top priority in our lives. 3. We have decided that we are learning to please ourselves not others. 4. We are committed to completing what we started. 5. We have become open-minded to other's thoughts and opinions. 6. We have a need to perform our work correctly in order to feel successful. 7. We have learned that our needs must come first. 8. We have learned not to be so hard on ourselves. 9. We have learned that it is okay to change our career paths and we grow. 10. We have learned to stay committed to staying in school. Social Values 1. Our......

Words: 492 - Pages: 2

Free Essay

Application of Motivation and Emotion Principles in Weight Loss Programs to Lose Weight Effectively.

...Application of motivation and emotion principles in weight loss programs to lose weight effectively. Abstract Application of principles of motivation and emotion has significant influence on the effectiveness of weight loss in weight loss programs. I agree with this view and will justify it by introducing principles and backing them up with official academic research as evidence. Adverse emotions can facilitate weight gain and disruptions in dieting. I believe principles such as Drive Theory, Self-Determination, Self-Confrontation and Self-Efficacy can counter weight gain and promote weight loss in weight loss programs. The concept of exercise opposes this view as it states that it the level and moderation of physical activity directly affects motivation and emotion and hence, the regulation of motivation and emotion cannot do without exercise. However, further analysis will explain why this opposing argument is not concrete. The essay will demonstrate tighter links with how principles of motivation and emotion affect the measures of effectiveness in weight loss programs. Application of motivation and emotion principles in weight loss programs to lose weight effectively. Effects of motivation and emotion are the underlying core factors behind weight loss success. Research has shown that motivation is a strong determinant in self-regulation during weight loss (Teixeira et al., 2006). Also, it is reported that there is positive relationships between......

Words: 3032 - Pages: 13