"Let there be light!"
Backlights in watches- a necessary component of everyday life, without it it is already impossible to imagine a modern wrist watch. This is a reality in which the quality of backlight manufacturing is everything.
Often found in wristwatches today electroluminescent backlight, but the backlight is gaining popularity day by day tritium.
Backlight Indiglo provided by the American company timex V 1992 year, is the best example electroluminescent backlight. We press the button, electricity is converted into light by applying a voltage of 100-200 volts to phosphorus atoms. Of course, a voltage converter (1:100) plays a role here, without which obtaining even a hundred volts would be impossible. Having received a charge, phosphorus atoms release photons, they illuminate the dial. The name itself "Indiglo" came from the word "Indigo". It is the color indigo(something between blue and purple) the dial of the watch model of the family Ironman. This series of watches was the first in the history of the company timex equipped with backlight Indiglo.
The ubiquitous Japanese corporation Casio could not stay away 1995 year, responding to the invention of the Americans by backlighting illuminator. Backlight Casio Illuminator in its device is similar to the backlight Indiglo. backlight in japan illuminator is called "Fox Fire".
Only the hands and markers of a single dial can be equipped with tritium illumination, while the electroluminescent backlight illuminates the entire dial. But do not rush to jump to conclusions!
Applying tritium backlighting to dials is a much more complex process than installing electroluminescent backlighting. The tritium backlight does not require button presses and does not use auxiliary energy sources - whether it be a watch battery or solar energy. Accordingly, such illumination does not affect the margin " life force» watch energy carrier.
Tritium is a radioactive isotope of hydrogen used in thermonuclear weapons as a source of neutrons and fuel. “That's it, I've had enough, leave the watch with such a backlight to yourself, but I'd rather choose a harmless electroluminescent backlight!” - you think. And you will be wrong.
Tritium does not pose a radiation hazard, because it is enclosed in sealed containers made of borosilicate glass. But even if the watch dial suddenly cracked, and the sealed container with tritium was damaged, then nothing will threaten our health anyway. The containers located on the watch dials contain a relatively small amount of tritium, which, if leaked, will have time to escape into the atmosphere without adverse consequences for humans. The most important thing is not to inhale or swallow tritium. Especially when the leak came from a large container.
Long term service without any recharging - this is the main trump card of the tritium backlight. Tritium illumination can last as long as 25 years. During this time, the tritium in the tanks will be subject to radioactive beta decay, which causes the electrons that have appeared to act on the atoms of the phosphor. It is this process that gives a bright green glow to the hands and marks, which can help out the owner of the watch under any circumstances.
By the way, tritium illumination can be represented by a variety of colors, not only green, but also dark blue, yellow, orange, red, white. In the watch industry, however, it is green that is used, because the human eye perceives it as the brightest (intensity - 100%). Tritium backlight will lose half of its brightness in 12 years, and in 25 years of service it will “lose weight” by 80% of brightness.
Strongly sought after by military and firefighters Traser remarkable not only for their durability, but also for their tritium illumination trigalight. Does not lag behind famous company Luminox, giving a guarantee of 25 years for the continuous operation of the tritium backlight in their watches.
The backlight deserves a special mention. SuperLuminova. This system announced itself in 1993, clearly denoting its positive properties. Backlight operation SuperLumiNova made possible by strontium aluminate, a substance applied to the hands and hour markers. System SuperLumiNova does not contain radioactive substances, which means it will not lose its qualities over time, as happens with tritium illumination. For backlight SuperLuminova periodic "meetings" with sunlight or artificial light are important, they charge the luminous coating of the hands and marks with the necessary energy.
Some watches not only have an advanced dial lighting system, but can also be used as an independent source of illumination. Men's Watch – best to that example.
Their dial is illuminated by a high power LED, providing excellent watch reading in the dark. But as soon as we go beyond the boundaries of the dial, the flashlight built into the case, working in three modes. With clock lighting system details Victorinox Swiss Army Night Vision can be found in a separate article.
A variety of lighting systems in watches today are able to meet the needs of many people. Practical electroluminescent lighting in the watch timex, Casio contributes to the appearance of attractive prices for the models of these companies. More complex tritium illumination awaits on watch faces Traser And Luminox.
Simplicity and accessibility, or technical sophistication and innovation? The choice is yours!
("HiZh", 1977, No. 10)
Ivan was given a diva here.
“What,” he said, “for the devil:
There are five caps in the world,
And there is no heat and smoke,
Eco miracle light!
P. P. Ershov. The Little Humpbacked Horse
Not everyone can imagine why the clock glows. More than once I had to explain - verbally and in writing - that no, the element phosphorus has nothing to do with it. Watches owe their light to phosphors - substances capable of emitting in the form of radiation the excess energy that they received when excited, or, if you like, recharging, say, with visible light or ultraviolet rays. Quite often, the following question is asked: is this glow harmful to health? It tells about those phosphors that are applied to dials and hands, about what they are made of and how; briefly said about the hygienic side of the matter.
absorbing sun rays
Science and practitioners know many different phosphors. For example, bioluminophores (energy activator - biochemical reaction); electroluminophores, which begin to glow under the action of an electric discharge; chemiluminophores, excited chemical reactions, and many others. In the watch industry, only a small part of them is used, namely photoluminophores and radioluminophores.
If the substance, after excitation, emits only billionths of a second, then such a glow is called fluorescence (the word comes from the name of fluorspar - fluorite; some varieties of it glow). When a substance emits rays for minutes, hours, days, then this phenomenon is called phosphorescence, and luminous materials are called phosphors. Like the name of a chemical element, this word comes from the Greek "phosphorus" - luminiferous.
The term "phosphorus" in relation to luminescent substances appeared in the middle of the 17th century - after it was discovered that after calcination, some minerals acquire the ability to absorb the sun's rays, and then emit them in the dark. In 1612, Galileo became interested in such minerals; he left us one of the first descriptions of phosphorescence, but he could not explain the reason for this strange phenomenon.
Another 250 years passed before they managed to unravel the mystery of luminous stones... In the seventies of the last century, the English company "Balmain" began the industrial production of Balmain's luminous paint. As expected, its composition was a secret of the company. However, it was soon solved by the French chemist Verneuil. The scientist found that the basis of the paint is calcium sulfide, and it acquires the property of glowing due to an insignificant admixture of bismuth salts. Now such impurities are called activators.
Electrons in a trap
Phosphors, or crystal phosphors, consist of a base and an activator (for example, calcium sulfide and bismuth salts, as in Balmain's paint; there are many other combinations). However, not the entire phosphor has the ability to glow, but only some of its parts, the so-called luminescence centers, or phosphorescence centers. These are places where there are violations in the crystal lattice of the base. Here is how they arise: a mixture of base and activator is subjected to heat treatment; then a strictly defined amount of impurities enters the base lattice and their joint crystallization occurs; where this happened, the crystal lattice is broken. By the way, it was found that the penetration of impurities is facilitated by low-melting salts - floodplains, therefore, in the manufacture of a phosphor, they are specially introduced into the reaction mass.
There are three energy zones in crystal phosphorus; they differ in the extent to which their energy levels are filled with electrons; hence the name of the bands: filled, or valence (I), forbidden (II), unfilled, or conduction band (III). The probability of electrons from an ideal crystal falling into zone II is negligible, which is why it is called forbidden. When special impurities, activators, are introduced into the lattice, the picture changes at the places where they enter the lattice: in zone II, new levels appear - luminescence centers (C) and traps (L), into which phosphor electrons can climb.
In fact, of course, there are no real traps here, it's just that an electron can remain in such an energy state for quite a long time even after the excitation of the crystal ceases; the nature of this phenomenon is not yet fully understood. Under the action of thermal vibrations of the lattice, the electrons are gradually released from the traps, lose energy, and the phosphor glows. It was noticed that the duration of the afterglow is the longer, the lower the trap is located, that is, the more energy is required to release the electron.
Under the action of visible light or ultraviolet rays, from collision with fast moving charged particles (for example, alpha or beta), phosphor electrons are excited and move to higher energy levels. Returning then to the initial state, the electrons emit an excess of energy in the form of light quanta. With a simple eye, we see not individual flashes, but a continuous stream of light, but through a magnifying glass one can also observe single scintillations, although the duration of each is about 0.00005 seconds.
Long-lived phosphors
Phosphors are divided into temporary and permanent. Remember Christmas decorations covered with luminescent paints. These paints contain short-lived phosphors... The lamps are off. Toys glow brightly. But after a while they are no longer visible. If you turn the light on again and then turn it off, the toys will light up again.
The basis of the luminous compounds of temporary action are sulfur compounds of zinc, calcium, cadmium, strontium, barium. They are calcined with negligible amounts of salts of heavy metals: copper, manganese, bismuth. Some phosphors glow blue, others red, others green.
For watches, phosphors that do not glow for a short time are inconvenient (although earlier, and sometimes, unfortunately, some enterprises still use such substances). The dials must be visible at least 10-12 hours after illumination. Among temporary phosphors, there are such compositions. For example, strontium sulfide phosphor; it emits light for about 12 hours without recharging. But this substance has a significant drawback: in the presence of moisture, strontium sulfide is hydrolyzed and hydrogen sulfide is released - an aggressive gas that corrodes the watch mechanism.
In watchmaking, permanent phosphors are increasingly used. Such centenarians include radioluminophores. In addition to the usual base and activator, their composition also includes an energy source - a radioactive substance. Luminescent mixtures of this kind do not need periodic illumination: the phosphor is forced to work by charged particles emitted by a radioactive additive.
There are strict requirements for radioactive additives in the watch industry. Initially, radium-220 compounds were introduced into phosphors. But its half-life is 1500 years. Watches grew old, broke, and the dial continued to be a source of radioactive radiation. Later it became clear that tritium, promethium-147, carbon-14 are more acceptable as energy sources in luminescent compositions. They live for about 10 years. In addition, these substances emit soft beta rays, which is also very important.
The more radioactive material is added to the phosphorescent mass, the brighter it glows. But the constant bombardment of charged particles does not go unnoticed for the phosphor itself. If there are too many particles and they carry too much energy, the luminescence centers of the phosphors are quickly destroyed. They let the tenants into the house, and they ruined it ... Therefore, those that emit beta rays are taken from radioactive substances: firstly, they destroy the phosphor less, and, secondly, they are almost completely absorbed by the watch case and glass.
Phosphors are subject to strict sanitary and hygienic requirements. At one time, the amount of radioactive radiation from dials with a permanent luminous mass was carefully measured, and doctors came to the conclusion that it is possible to wear watches with such phosphors, they do not pose a threat to health. However, the problems of industrial hazards have not been completely resolved: how to apply luminous compositions, while observing safety rules; where to put the waste; how to store large batches of such watches. This led to the fact that in 1958 the production of watches with radioactive light mass was discontinued in the USSR. Now, thanks to the efforts of technologists, chemists, physicians and engineers, special areas have been created where phosphors are prepared and applied; these areas meet all safety requirements.
phosphor caprice
The phosphorescent mixture is a colorless crystalline powder, very delicate and capricious: the destruction of the crystal lattice or the appearance of foreign impurities sharply reduces the brightness of its glow. And yet, the powder has to be subjected to some processing. At least in order to glue it to the dial.
The best thing would be, of course, to enclose the crystals in a transparent shell and attach them to the watch in this form. But this method is not always possible. So, binders are needed: glues, varnishes. With their help, by the way, they not only keep the phosphor on the dial, but also protect it from atmospheric moisture, mechanical damage and even from ultraviolet rays that can destroy the luminous coating.
Most often in the watch industry, acrylic, vinylite and polystyrene varnishes are used; rarely use zaponlak or cellulose acetate; and special preference is given to dammar pack, it forms a strong transparent film, impervious to ultraviolet rays.
The amount of binder mixed with the phosphor is usually very small, otherwise the varnish envelops the crystals and greatly reduces the brightness of their glow. The components are carefully mixed in glass or porcelain dishes; there can be no talk of rubbing the mixture. Prepare the composition immediately before application. The finished mixture is applied with a brush, pen, glass rod, syringe or using a printing machine.
Not so long ago, reports appeared in foreign literature about another method for applying phosphorescent mixtures - about the method of depositing them from electrolytes together with metals: nickel, silver, palladium, gold. A beautiful combined coating is formed on the dial, it looks equally good both in the light and in the dark.
Now the country's watch industry produces watches with dials that are covered with permanent phosphors in several versions, for example, "Amphibian" for scuba divers. (In addition, they still make alarm clocks with dials on which luminescent paint is applied, but it does not perform its role well - after one and a half to two hours after recharging it no longer glows.) In the future, the range of watches with long-lived phosphors will expand, their production will increase .
Candidate of Technical Sciences E. Ya. Besidovsky,
Watch Industry Research Institute
When choosing a watch, future owners will certainly look at what the mechanism costs, what the case and glass are made of, what kind of material the strap or bracelet is. The question of which watch backlight is better arises less frequently. Meanwhile, the execution of this function is seriously different in the models of different watch brands. We will tell you which illuminated watches are comfortable to wear every day in the city, which ones will light your way on a hiking trip, and which ones will pierce the water column with their powerful light when scuba diving.
Clock luminescent lighting
Back in the 19th century, Swiss craftsmen invented a way to keep the readability of the pocket watch dial in the dark - the hands and indexes were treated with a luminous substance, barium sulfide. Today, luminescent lighting of watches is found in the collections of TAG Heuer, Breitling, Corum and other leaders in the watch industry. Manufacturers process indexes, hands and bezels of watches with light-accumulative compositions.
Breitling Professional EVO Night Mission Pilot's Watch Dial with Luminescent Markers
SuperLuminova
In 1993, the Japanese company Nemoto introduced a light-accumulative composition (phosphor) based on strontium aluminate. Prior to this, the basis for phosphors for the most part served as zinc sulfide. The novelty shone ten times brighter and longer than its predecessors, in addition, it was non-toxic and economical - the pigment did not fade for years. The composition was named Luminova. The phosphor was "recharged" by contact with light waves of 200-400 nm, the initial color was green. In 1998, it was established industrial production, and in 2000 an improved version of SuperLuminova was released - one of the most popular watch lights today.
Cozy green glow
SuperLuminova is twice as bright as the 1993 composition, and divers love watches with this illumination. The dial markers treated with phosphor are perfectly readable at any depth. A striking example is the TAG Heuer Aquaracer watch, which has already become a classic piece of diving equipment. The model's faceted indexes and hands are coated with white SuperLuminova. The glow time from the moment of contact with the light source is 6-12 hours. At the same time, the clock will not go out at one moment - the backlight brightness will gradually decrease every hour. Watches with such illumination are suitable for deep-sea diving, and for a long evening walk.
Clock with LED backlight
LED-backlit watches are popular due to their convenience and their bright light. It is enough to press one button on the case and small LEDs located along the entire diameter will evenly illuminate the entire dial. In the famous G-Shock collection of the Japanese brand Casio, many models are released with LED-backlighting, activated intuitively - when poor lighting Just turn your hand and it will turn on by itself.
military reliable model GA700 Camo Series Non Shave
Tritium (superheavy hydrogen) is a radioactive isotope of hydrogen, which is actively used in the production of nuclear weapons. Surely, such a characteristic sounds at least alarming, but fears are in vain - the radioactive element is securely enclosed in sealed containers made of borosilicate glass. Even if the container is damaged, the substance is not capable of harming health due to the small amount. It is only important to remember that in no case should you swallow and inhale tritium!
tritium flasks
If the LED backlight depends on the battery, and the luminous backlight, although it lasts a long time, but requires mandatory contact with the light source, the tritium backlight of the watch does not need external recharging and lasts about 25 years. This is due frequent use tritium in the creation of night vision devices for the army, aviation and navy.
Trigalight
Trigalight (GTLS, trigalight) - self-activated tritium illumination technology wrist watch, developed by the Swiss company Mb-microtec. The concern has been developing tritium light sources since 1968. The first wristwatch with a trigalight brand Traser was released in 1991 by order of the US Department of Defense. The US Army ordered 60,000 watches for units involved in Operation Desert Storm. The debut model Traser P6500 Type 6 was released until 2003.
Traser classic militari watch with trigalight
Today, tritium backlit Traser watches are worn by military personnel in 59 countries. Also, the brand has become a favorite among fans of extreme tourism.
Watch Luminox
When choosing a model whose dial is readable in any light, pay attention to water protection.
More than one billion watches are produced annually in the world: manual, wall, souvenir. There are a lot of options for execution and, it would seem, it is difficult to surprise a potential buyer, but ...
There is a luminous paint for various kinds original surfaces (metal, plastic, wood, glass, etc.), thanks to which you can build a profitable business or open a new direction in an existing business. It's about transforming an ordinary watch into a luminous one.
What can glow in the clock
If it is a wall clock with arrows, then the arrows, dial numbers, background, body can be glowing in the dark. A wall clock can be with a pendulum, in which case the option of a luminous pendulum is interesting, and if the clock is with a cuckoo, then a jumping luminous cuckoo will amuse anyone. Wristwatches will become exclusive and youthful thanks to a luminous strap, functional - thanks to a luminous dial.
How to make a glow on the clock
Within the scope of this article will not dwell on technological process production of watch parts. For this, there are special productions that are just beginning to successfully master the new nomenclature for themselves. It will soon be possible to buy watches with a luminous dial in many countries.
Consider the decor option already ready wall clock and manufacturing of designer exclusive watches. A variety of luminous colors for various types of surfaces, a palette of 8 colors and 2 glow options allows you to create unique masterpieces even from ordinary office clocks.
Easiest to paint design options hours, because paint the workpiece without established mechanism It is possible with the help of an airbrush, which at times increases the intensity of the glow of the finished coating. The fact is that when painting with an airbrush, a uniform distribution of luminous particles occurs, which is more difficult to do with a brush. Although small parts you still have to paint with a brush.
It's easy to make luminous elements with Acmelight™ self-adhesive luminous film.
In general, we determine our capabilities and desires.
How to sell luminous watches
On initial stage you need to understand which stores and outlets you will deliver to. Options may be the following: shops selling office supplies, children's goods, exclusive gift shops, electrical goods stores. I’m not talking about an electrical goods store by chance. The fact is that a watch that glows in complete darkness can be regarded as an excellent Alternative option electronic clock who buy to see the scoreboard in the dark. The luminous dial and hands are perfectly visible at night and do not require an electrical connection, which is very convenient to use.
After we have determined directions for ourselves, we make samples of watches for demonstration. With these samples, you can visit the shops of the city, and we send the photographs taken with the clock options in daylight and in complete darkness with a proposal for cooperation to all potential customers and place ads on bulletin boards.
Opening of a watch dyeing workshop
The list of services may include the conversion of both new and old watches; branding with luminous paint; drawing children's pictures, youth slogans, etc. Of course, as an independent direction, such a business is unlikely to be profitable, but within the framework of the existing one, it will attract new customers and increase sales in other directions (if they are "consonant"). For example, if you are in the business of branding branded merchandise, then offering luminous designs on watches will make your offer much more attractive. Watches are often considered as an option for a corporate gift and they can be ordered in large quantities. And with this approach, there can be a good income.
Hourglass - also a clock, but more for decoration
Such watches can be made using as a luminous bulk material, which is also available from Acmelight. The stunning effect of such hours in the dark will not leave anyone indifferent.
Man has long sought to create technical utility. He also learned to measure time. However, even now he has not invented an ideal way to illuminate the hour hands in the dark. The most famous material that is used to illuminate the clock face- luminescence. This function allows you to see the time on the dial in low light. The luminescent way of illumination is also called "cold light". On clock hands A special coating is applied that glows in the dark. But in order to emit light in the dark, a watch with such a coating must stay for some time in bright light, then it is charged with energy and gives it back in the dark. Several types of luminescence :
- chemiluminescence;
- photoluminescence;
- radioluminescence.
Previously, photoluminescent and radioluminescent methods were most often used to illuminate the clock dial. Radioluminescence occurs as a result of nuclear radiation. Until the Second World War, people did not understand the full danger of radioactive radiation. Even after the full risk of using radiation was known, some stores continued to sell watches with radium-treated dials.
remains popular today photoluminescent coating. In this case, light energy occurs as a result of hard electromagnetic radiation. Such material absorbs light energy for a long time. Then it emits light much longer than it absorbed.
There is another substance that is used to illuminate the hour hands - tritium. Tritium is a radioactive isotope of hydrogen. Its radioactivity is almost completely absorbed by the dial glass. Tritium complies with the international standards NIHS 97-10 and ISO 3157. These standards are designed to determine minimum quantity luminescent material needed to see the time on the clock face in the dark. If tritium contains a high-quality luminescent substance, it can retain light emission for several years. The illumination intensity also depends on the volume of the coating and the thickness of the applied layer. Despite the low radioactivity of tritium, it still did not win one hundred percent trust among people. Concerns of consumers and requirements of some countries to provide a certificate environmental safety, are forcing watch manufacturers to look for new types of illumination of watch dials.
Japanese watch companies have recently started using completely new materials: LumiBright and LumiNova. Although they best quality, however, are not able to maintain the ability to glow for a long time. Such a watch dial must be constantly recharged - kept under bright light.
Today, the Swiss Association for Watchmaking (ASRH) spends a lot of money on research to improve photoluminescence. However, so far, tritium is the best substance that solves the problem of time indication in poor lighting conditions.
