Remote control
For other uses, see Remote control (disambiguation).
A remote control is a component of an electronics device, most commonly a television set,DVD player and home theater systems originally used for operating the device wirelesslyfrom a short line-of-sight distance. Remote control has continually evolved and advanced over recent years to include Bluetooth connectivity, motion sensor-enabled capabilities and voice control.[1][2]
Commonly, remote controls are Consumer IR devices used to issue commands from a distance to televisions or other consumer electronics such as stereo systems, DVD players and dimmers. Remote controls for these devices are usually small wireless handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote control contains all the function controls while the controlled device itself has only a handful of essential primary controls. Most of these remote controls communicate to their respective devices via infrared signals and a few via radio signals. Earlier remote controls in the 1970s used ultrasonic tones. The remote control code, and thus the required remote control device, is usually specific to a product line, but there are universal remotes, which emulate the remote control made for most major brand devices.
The main technology used in home remote controls is infrared (IR) light. The signal between a remote control handset and the device it controls consists of pulses of infrared light, which is invisible to the human eye.
History[edit]
The earliest example of remote control by radio waves was developed in 1898 by Nikola Tesla and described in his patent, U.S. Patent 613,809, named Method of an Apparatus for Controlling Mechanism of Moving Vehicle or Vehicles. In 1898, he demonstrated a radio-controlled boat to the public during an electrical exhibition at Madison Square Garden. Tesla called his boat a "teleautomaton".[3]
In 1903, Leonardo Torres Quevedo presented the Telekino at the Paris Academy of Science, accompanied by a brief, and making an experimental demonstration. In the same time he obtained a patent in France, Spain, Great Britain, and the United States. TheTelekino consisted of a robot that executed commands transmitted by electromagnetic waves. With the Telekino, Torres-Quevedo laid down modern wireless remote-control operation principles[4] and was a pioneer in the field of remote control. In 1906, in the presence of the king and before a great crowd, Torres successfully demonstrated the invention in the port of Bilbao, guiding a boat from the shore. Later, he would try to apply the Telekino to projectiles and torpedoes, but had to abandon the project for lack of financing.
The first remote-controlled model aeroplane flew in 1932, and the use of remote control technology for military purposes was worked intensively during the Second World War, one result of this being the German Wasserfall missile.
By the late 1930s, several radio manufacturers offered remote controls for some of their higher-end models.[5] Most of these were connected to the set being controlled by wires, but the Philco Mystery Control (1939) was a battery-operated low-frequency radio transmitter,[6] thus making it the first wireless remote control for a consumer electronics device.
Television remote controls[edit]
The first remote intended to control a television was developed by Zenith Radio Corporation in 1950. The remote, called "Lazy Bones", was connected to the television by a wire. A wireless remote control, the "Flashmatic", was developed in 1955 by Eugene Polley. It worked by shining a beam of light onto a photoelectric cell, but the cell did not distinguish between light from the remote and light from other sources. The Flashmatic also had to be pointed very precisely at the receiver in order to work.[7]
In 1956, Robert Adler developed "Zenith Space Command", a wireless remote.[8] It was mechanical and used ultrasound to change the channel and volume. When the user pushed a button on the remote control, it clicked and struck a bar, hence the term "clicker". Each bar emitted a different frequency and circuits in the television detected this sound. The invention of the transistor made possible cheaper electronic remotes that contained a piezoelectric crystal that was fed by an oscillating electric current at a frequency near or above the upper threshold ofhuman hearing, though still audible to dogs. The receiver contained a microphone attached to a circuit that was tuned to the same frequency. Some problems with this method were that the receiver could be triggered accidentally by naturally occurring noises, and some people could hear the piercing ultrasonic signals. There was an incident in which a toy xylophone changed the channels on such sets because some of the overtones from the xylophone matched the remote's ultrasonic frequency.[citation needed]
The impetus for a more complex type of television remote control came in the late 1970s, with the development of the Ceefax teletextservice by the BBC. Most commercial remote controls at that time had a limited number of functions, sometimes as few as three: next channel, previous channel, and volume/off. This type of control did not meet the needs of teletext sets, where pages were identified with three-digit numbers. A remote control to select teletext pages would need buttons for each numeral from zero to nine, as well as other control functions, such as switching from text to picture, and the normal television controls of volume, channel, brightness, colour intensity, etc. Early teletext sets used wired remote controls to select pages, but the continuous use of the remote control required for teletext quickly indicated the need for a wireless device. So BBC engineers began talks with one or two television manufacturers, which led to early prototypes in around 1977–1978 that could control many more functions. ITT was one of the companies and later gave its name to the ITT protocol of infrared communication.[9]
In 1980, a Canadian company, Viewstar, Inc., was formed by engineer Paul Hrivnak and started producing a cable TV converter with an infrared remote control. The product was sold through Philips for approximately $190 CAD. At the time the most popular remote control was the Starcom of Jerrold (a division of General Instruments) which used 40-kHz sound to change channels. The Viewstar converter was an immediate success, the millionth converter being sold on March 21, 1985, with 1.6 million sold by 1989.[10]
In 2006, Hillcrest Labs introduced the Loop pointer, a remote control that used Hillcrest's Freespace motion control technology to allow users to control their televisions with natural gestures. The Loop had just four buttons and a scroll wheel.[11][12][13][14] Freespace-enabled remote controls use radio waves to communicate with a USB antenna connected to a computer that is also connected to the television, so they do not need to be pointed at the PC, or even have a direct line of sight.[15][16][17]
Some television manufacturers now include Bluetooth remotes to control the television without requiring line of sight, overcoming the limited range in IR-based remotes.
Effect of the early television remote control[edit]
The invention of the remote control has led to several changes in television programming. One was the creation of split screen credits. According to James Gleick, an NBC research team discovered that when the credits started rolling after a program, 25% of its viewers would change the channel before it was over. Because of this, the NBC 2000 unit invented the "squeeze and tease" which squeezed the credits onto one third of the screen while the final minutes of the broadcast aired simultaneously.[19]The remote allowed audiences, for the first time, to interact with their TV without touching it. They no longer watched programs just because they did not want to get up to change the channel.[18] They could also channel surf during commercials, or turn the sound off.
The remote control also led to an adjustment in commercial airings. Networks began to feel that they could not afford to have commercials between programs because it would detract viewers from staying tuned in to their channel. Programmers decided to place commercials in the middle of programs to make the transition to the next show direct.[20]
Other remote controls[edit]
In the 1980s Steve Wozniak of Apple started a company named CL 9. The purpose of this company was to create a remote control that could operate multiple electronic devices. The CORE unit (Controller Of Remote Equipment) was introduced in the fall of 1987. The advantage to this remote controller was that it could “learn” remote signals from different devices. It had the ability to perform specific or multiple functions at various times with its built-in clock. It was the first remote control that could be linked to a computer and loaded with updated software code as needed.
The CORE unit never made a huge impact on the market. It was much too cumbersome for the average user to program, but it received rave reviews from those who could.[citation needed] These obstacles eventually led to the demise of CL 9, but two of its employees continued the business under the name Celadon. This was one of the first computer-controlled learning remote controls on the market.[21]
The proliferation of remote controls[edit]
By the early 2000s, the number of consumer electronic devices in most homes greatly increased, along with the number of remotes to control those devices. According to the Consumer Electronics Association, an average American home has four remotes.[citation needed]To operate a home theater as many as five or six remotes may be required, including one for cable or satellite receiver, VCR or digital video recorder (DVR/PVR), DVD player, TV and audio amplifier. Several of these remotes may need to be used sequentially but, as there are no accepted interface guidelines, the process is increasingly cumbersome.
Many specialists, including Jakob Nielsen, a renowned usability specialist, and Robert Adler, the inventor of the modern remote, note how confusing, unwieldy and frustrating the multiplying remotes have become.[22] Because of this proliferation of remote controls,universal remote controls that manage multiple devices are becoming increasingly popular.
Remote control applications on mobile devices[edit]
In the late 2000s to early 2010s, a number of smartphone and portable media player platforms were provided with installable software applications which allow for the remote controlling of media centers and media players on home theater PCs and general-purpose personal computers over Wi-Fi, such as iTunes Remote on iOS. In comparison to the user interfaces of physically buttoned dedicated remote control devices, the user interfaces of these remote control applications are designed to take advantage of the dynamic graphics offered by touchscreen handheld devices, making for larger virtual buttons and virtual keyboards.
Most developers of remote control applications for handhelds usually architect the software for usage with specific media player or media center applications (i.e., iTunes Remote for iTunes and iTunes-based software from Apple, Boxee remote[23] for Boxee, DVR Remote[24] for TiVo, VLC Remote[25] for VLC, etc.).
Technique[edit]
The main technology used in home remote controls is infrared (IR) light. The signal between a remote control handset and the device it controls consists of pulses of infrared light, which is invisible to the human eye, but can be seen through a digital camera, video camera or a camera phone. The transmitter in the remote control handset sends out a stream of pulses of infrared light when the user presses a button on the handset. A transmitter is often a light emitting diode (LED) which is built into the pointing end of the remote control handset. The infrared light pulses form a pattern unique to that button. The receiver in the device recognizes the pattern and causes the device to respond accordingly. [26]
The opto components, circuits and mathematics[edit]
Most remote controls for electronic appliances use a near infrared diode to emit a beam of light that reaches the device. A 940 nm wavelength LED is typical. This infrared light is invisible to the human eye, but picked up by sensors on the receiving device. Video cameras see the diode as if it produces visible purple light.
With a single channel (single-function, one-button) remote control the presence of a carrier signal can be used to trigger a function. For multi-channel (normal multi-function) remote controls more sophisticated procedures are necessary: one consists of modulating the carrier with signals of different frequency. After the receiver demodulates the received signal, it applies the appropriate frequency filters to separate the respective signals. One can often hear the signals being modulated on the infrared carrier by operating a remote control in very close proximity to an AM radio not tuned to a station. Today, IR remote controls almost always use a pulse width modulated code, encoded and decoded by digital computer: a command from a remote control consists of a short train of pulses of carrier-present and carrier-not-present of varying widths.
Consumer electronics infrared protocols[edit]
Different manufacturers of infrared remote controls use different protocols to transmit the infrared commands. The RC-5 protocol that has its origins within Philips, uses, for instance, a total of 14 bits for each button press. The bit pattern is modulated onto acarrier frequency that, again, can be different for different manufacturers and standards, in the case of RC-5, the carrier is 36 kHz. Other consumer infrared protocols include the various versions of SIRCS used by Sony, the RC-6 from Philips, the Ruwido R-Step, and the NEC TC101 protocol.
Infrared, line of sight and operating angle[edit]
Since infrared (IR) remote controls use light, they require line of sight to operate the destination device. The signal can, however, be reflected by mirrors, just like any other light source.
If operation is required where no line of sight is possible, for instance when controlling equipment in another room or installed in a cabinet, many brands of IR extenders are available for this on the market. Most of these have an IR receiver, picking up the IR signal and relaying it via radio waves to the remote part, which has an IR transmitter mimicking the original IR control.
Infrared receivers also tend to have a more or less limited operating angle, which mainly depends on the optical characteristics of thephototransistor. However, it's easy to increase the operating angle using a matte transparent object in front of the receiver.
Radio remote control systems[edit]
Radio remote control (RF remote control) is used to control distance objects using a variety of radio signals transmitted by the remote control device. As a complementary method to infrared remote controls, the radio remote control is used with electric garage door or gate openers, automatic barrier systems, burglar alarms and industrial automation systems.
Usage[edit]
Industry[edit]
Remote control is used for controlling substations, pump storage power stations andHVDC-plants. For these systems often PLC-systems working in the longwave range are used.
Military[edit]
Remote controls in military usage employ jamming and countermeasures against jamming. Jammers are used to disable or sabotage the enemy's use of remote controls. The distances for military remote controls also tend to be much longer, up to intercontinental distance satellite linked remote controls used by the U.S. for their unmanned airplanes (drones) in Afghanistan, Iraq and Pakistan.
Remote controls are used by insurgents in Iraq and Afghanistan to attack coalition and government troops with roadside improvised explosive devices, and terrorists in Iraq are reported in the media to use modified TV remote controls to detonate bombs.[27]
Military history[edit]
In World War I, the Imperial German Navy employed FL-boats (Fernlenkboote) against coastal shipping. These were driven by internal combustion engines, and controlled remotely from a shore station through several miles of wire wound on a spool on the boat. An aircraft was used to signal directions to the shore station. EMBs carried a high explosive charge in the bow and traveled at speeds of thirty knots.[28]
The Soviet Red Army used remotely controlled teletanks during 1930s in the Winter War against Finland and the early stages of World War II. A teletank is controlled by radio from a control tank at a distance of 500 to 1,500 meters, the two constituting a telemechanical group. The Red Army fielded at least two teletank battalions at the beginning of the Great Patriotic War. There were also remotely controlled cutters and experimental remotely controlled planes in the Red Army.
Space[edit]
Remote control technology is also used in space travel, for instance the Soviet Lunokhodvehicles were remote-controlled from the ground. Many space exploration rovers can be remotely controlled, though vast distance to a vehicle results in a long time delay between transmission and receipt of a command.
Video games[edit]
Video game consoles had not used wireless controllers until recently, mainly because of the difficulty involved in playing the game while keeping the infrared transmitter pointed at the console. Early wireless controllers were cumbersome and when powered on alkaline batteries, lasted only a few hours before they needed replacement. Some wireless controllers were produced by third parties, in most cases using a radio link instead of infrared. Even these were very inconsistent, and in some cases, had transmission delays, making them virtually useless. The first official wireless game controller made by a first party manufacturer was the CX-42 for Atari 2600. In the current generation of gaming consoles, wireless controllers are now standard.
Some wireless controllers, such as the Sony PS3 and Nintendo Wii, use Bluetooth. Others, like the Xbox 360, use proprietary wireless protocols.
PC control[edit]
Existing infrared remote controls can be used to control PC applications. Any application that supports shortcut keys can be controlled via IR remote controls from other home devices (TV, VCR, AC).[citation needed] This is widely used[citation needed] with multimedia applications for PC based home theatre systems. For this to work, one needs a device that decodes IR remote control data signals and a PC application that communicates to this device connected to PC. Connection can be made via serial port, USB port or motherboardIrDA connector. Such devices are commercially available but can be home made using low cost micro controllers.[citation needed]
LIRC(Linux IR Remote control) and Win-LIRC (for Windows) are software packages developed for the purpose of controlling PC using TV remote and can be also used for homebrew remote with lesser modification.
Photography[edit]
Remote controls are used in photography, in particular to take long-exposure shots.[29]
Standby power[edit]
To be turned on by a wireless remote, the controlled appliance must always be partly on, consuming standby power.[30]
Alternatives[edit]
Hand-gesture recognition has been researched as an alternative to remote controls for television sets.[31]
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