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IPhone 4
The iPhone 4 is a smartphone that was developed and marketed by Apple Inc. It is the List of iPhone models, fourth generation of the iPhone lineup, succeeding the iPhone 3GS and preceding the iPhone 4s. Following a number of notable leaks, the iPhone 4 was first unveiled on June 7, 2010, at Apple's Worldwide Developers Conference in San Francisco, and was released on June 24, 2010, in the United States, United Kingdom, France, Germany, and Japan. The iPhone 4 introduced a new hardware design to the iPhone family, which Apple's CEO Steve Jobs touted as the thinnest smartphone in the world at the time; it consisted of a stainless steel frame which doubled as an antenna, with internal components situated between two panels of aluminosilicate glass. The iPhone 4 introduced Apple's new high-resolution "Retina display" (with a pixel density of 326 pixels per inch), while maintaining the same physical size and aspect ratio as its precursors, Apple's Apple A4, A4 system-on-chip, alo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPhone 4 Logo
The iPhone is a line of smartphone, smartphones developed and marketed by Apple Inc., Apple that run iOS, the company's own mobile operating system. The iPhone (1st generation), first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at Macworld 2007, and launched later that year. Since then, Apple has annually released new List of iPhone models, iPhone models and IOS version history, iOS versions; the most recent models being the iPhone 16 and 16 Plus, alongside the higher-end iPhone 16 Pro and 16 Pro Max, and the lower-end iPhone 16e (which replaces the iPhone SE). As of January 1, 2024, more than 2.3 billion iPhones have been sold, making Apple the List of best-selling mobile phones#2023, largest vendor of mobile phones in 2023. The original iPhone was the first mobile phone to use multi-touch technology. Throughout History of the iPhone, its history, the iPhone has gained larger, Retina display, higher-resolution displays, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Memory
Flash memory is an Integrated circuit, electronic Non-volatile memory, non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR gate, NOR and NAND gate, NAND logic gates. Both use the same cell design, consisting of floating-gate MOSFETs. They differ at the circuit level, depending on whether the state of the bit line or word lines is pulled high or low; in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate. Flash memory, a type of floating-gate memory, was invented by Fujio Masuoka at Toshiba in 1980 and is based on EEPROM technology. Toshiba began marketing flash memory in 1987. EPROMs had to be erased completely before they could be rewritten. NAND flash memory, however, may be erased, written, and read in blocks (or pages), which generally are much smaller than the entire devi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coating
A coating is a covering that is applied to the surface of an object, or substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. powder coatings. Paints and lacquers are coatings that mostly have dual uses, which are protecting the substrate and being decorative, although some artists paints are only for decoration, and the paint on large industrial pipes is for identification (e.g. blue for process water, red for fire-fighting control) in addition to preventing corrosion. Along with corrosion resistance, functional coatings may also be applied to change the surface properties of the substrate, such as adhesion, wettability, or wear resistance.Howarth G.A "Synthesis of a legislation compliant corrosion protection coating system based on urethane, oxazolidine and waterborne epoxy technology" Master of Science Thesis April 1997 Imperial College London In other cases the coating adds a co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipophobicity
Lipophobicity, also sometimes called lipophobia (from the Greek λιποφοβία from λίπος ''lipos'' "fat" and φόβος ''phobos'' "fear"), is a chemical property of chemical compounds which means " fat rejection", literally "fear of fat". Lipophobic compounds are those not soluble in lipids or other non-polar solvents. From the other point of view, they do not absorb fats. "Oleophobic" (from the Latin ''oleum'' "oil", Greek ελαιοφοβικό ''eleophobico'' from έλαιο ''eleo'' "oil" and φόβος ''phobos'' "fear") refers to the physical property of a molecule that is seemingly repelled from oil. (Strictly speaking, there is no repulsive force involved; it is an absence of attraction.) The most common lipophobic substance is water. Fluorocarbons are also lipophobic/oleophobic in addition to being hydrophobic. Uses A lipophobic coating has been used on the touchscreens of Apple's iPhones since the 3GS, their iPads, Nokia's N9 and Lumia devices, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fingerprint
A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfaces such as glass or metal. Deliberate impressions of entire fingerprints can be obtained by ink or other substances transferred from the peaks of friction ridges on the skin to a smooth surface such as paper. Fingerprint records normally contain impressions from the pad on the last joint of fingers and thumbs, though fingerprint cards also typically record portions of lower joint areas of the fingers. Human fingerprints are detailed, unique, difficult to alter, and durable over the life of an individual, making them suitable as long-term markers of human identity. They may be employed by police or other authorities to identify individuals who wish to conceal their identity, or to identify people who are incapacitated or dead and thus unab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminance
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls within a given solid angle. The procedure for conversion from spectral radiance to luminance is standardized by the CIE and ISO. Brightness is the term for the ''subjective'' impression of the ''objective'' luminance measurement standard (see for the importance of this contrast). The SI unit for luminance is candela per square metre (cd/m2). A non-SI term for the same unit is the nit. The unit in the Centimetre–gram–second system of units (CGS) (which predated the SI system) is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. Description Luminance is often used to characterize emission or reflection from flat, diffuse surfaces. Luminance levels indicate how much luminous power could be det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast Ratio
The contrast ratio (CR) is a property of a display system, defined as the ratio of the luminance of the brightest shade (white) to that of the darkest shade (black) that the system is capable of producing. A high contrast ratio is a desired aspect of any display. It has similarities with dynamic range. There is no official, standardized way to measure contrast ratio for a system or its parts, nor is there a standard for defining "Contrast Ratio" that is accepted by any standards organization so ratings provided by different manufacturers of display devices are not necessarily comparable to each other due to differences in method of measurement, operation, and unstated variables. Manufacturers have traditionally favored measurement methods that isolate the device from the system, whereas other designers have more often taken the effect of the room into account. An ideal room would absorb all the light reflecting from a projection screen or emitted by a cathode-ray tube, and the on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel Density
Pixels per inch (ppi) and pixels per centimetre (ppcm or pixels/cm) are measurements of the pixel density of an electronic image device, such as a computer monitor or television display, or image digitizing device such as a camera or image scanner. Horizontal and vertical density are usually the same, as most devices have square pixels, but differ on devices that have non-square pixels. Pixel density is not the same as where the former describes the amount of detail on a physical surface or device, the latter describes the amount of pixel information regardless of its scale. Considered in another way, a pixel has no inherent size or unit (a pixel is actually a sample), but when it is printed, displayed, or scanned, then the pixel has both a physical size (dimension) and a pixel density (ppi). Basic principles Since most digital hardware devices use dots or pixels, the size of the media (in inches) and the number of pixels (or dots) are directly related by the 'pixels per inch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Resolution
Image resolution is the level of detail of an image. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how close lines can be to each other and still be visibly ''resolved''. Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to the overall size of a picture (lines per picture height, also known simply as lines, TV lines, or TVL), or to angular subtense. Instead of single lines, line pairs are often used, composed of a dark line and an adjacent light line; for example, a resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter (5 LP/mm). Photographic lens are most often quoted in line pairs per millimeter. Types The resolution of digital cameras can be described in many different ways. Pixel count The term ''resolution'' is often considered eq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TFT LCD
A thin-film-transistor liquid-crystal display (TFT LCD) is a type of liquid-crystal display that uses thin-film transistor, thin-film-transistor technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven (i.e. with segments directly connected to electronics outside the LCD) LCDs with a few segments. TFT LCDs are used in television sets, computer monitors, mobile phones, video game systems, personal digital assistants, navigation systems, video projector, projectors, and dashboards in some automobiles and in medium to high end motorcycles. History In February 1957, J. Torkel Wallmark, John Wallmark of RCA filed a patent for a thin film MOSFET. Paul K. Weimer, also of RCA, implemented Wallmark's ideas and developed the thin-film transistor (TFT) in 1962, a type of MOSFET distinct from the standard bulk MOSFET. It was made with thin films of cadmium selenide and cadmium s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LED Backlit
A backlight is a form of illumination used in liquid-crystal displays (LCDs) that provides light from the back or side of a display panel. LCDs do not produce light on their own, so they require illumination—either from ambient light or a dedicated light source—to create a visible image. Backlights are commonly used in smartphones, computer monitors, and LCD televisions. They are also used in small displays, such as wristwatches, to enhance readability in low-light conditions. Typical light sources for backlights include light-emitting diodes (LEDs) and cold cathode fluorescent lamps (CCFLs). Simple types of LCDs, such as those used in pocket calculators, are built without an internal light source and rely on external light sources to make the display image visible to the user. However, most LCD screens are designed with an internal light source. These screens consist of multiple layers, with the backlight typically being the first layer from the back. Light valves regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AppleInsider
The Apple community consists of the users, media, and third party companies interested in Apple Inc. and its products. They discuss rumors, future products, news stories, and support of Apple's products. Apple has a devoted following, especially for the Apple II, Mac (computer), Mac, iPod, iPhone, and luminary staff members. The personal computer revolution, mixed with Apple's Vertical integration#Apple, vertical integration of its products and services, has increased popularity. Apple's corporate policy of extreme secrecy about future products intensify interest in the company's activities. Magazines Before the popular use of the internet, early Apple-related publications were available in traditional print media form, often but not always moving later to online publication. '' MacLife'' (stylized as ''Mac, Life'') is a San Francisco-based American publication, originally known as ''MacAddict'' between September 1996 and February 2007. Published by Future US, it started as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
