Views:3 Author:Site Editor Publish Time: 2017-12-15 Origin:Site
The electronic commodity anti-theft system is referred to as "EAS", also known as the electronic merchandise anti-theft system, the Chinese name electronic merchandise anti-theft system, and the foreign name Electronic Article Surveillance system. It is one of the commodity security measures widely used in the retail industry at present. EAS was born in the United States in the mid 1960s, originally used in the clothing industry, has now been extended to more than 80 countries and regions around the world. The application also extended to department stores, supermarkets, books, amusement parks and other industries, especially in supermarkets, clothing stores are fully developed.
01.a brief introduction to EAS
The EAS system is mainly composed of three parts: detector (detection system), decoder (demagnetizing device) and electronic label. The electronic label is divided into soft label and hard label. The soft label cost is low, and it is directly attached to the commodity. The soft label can not be reused. The first and second cost of hard label is higher than that of soft label, but it can be reused. The hard label must be equipped with a special staple to be reclaimed for the soft and penetrable items of the clothing. The decoder (demagnetizing device) is mostly non-contact device, which has a certain degree of decoding (degaussing). When the cashier cashier or bagging, the electronic tag can be decoded without touching the demagnetizing area. There will be a decoder and a laser barcode scanner to synthesis equipment, so the product collection and decoding time to complete, convenient cashier work, this way should be matched with the supplier and laser barcode, eliminate mutual interference between the two, improve the decoding sensitivity. The detector is usually the inspection system device at the entrance of the shopping mall or the channel of the silver collecting. After receiving a correct sum of money payable by a customer to purchase a commodity, the cashier can degausse and decode the label which is pasted on the commodity, and authorize the goods and leave the designated area legally. The undecoded merchandise is taken away from the shopping mall and will trigger the alarm when passing the detector device, so as to remind cashiers, customers and store security personnel to deal with them in a timely manner.
The EAS system is developing very fast, now can be divided into single system and multi bit system.
Multi bit system is representative of the radio frequency identification system (RFID system), radio frequency identification technology RFID (Radio Frequency Identification) is a term used to describe any device for sensing by radio frequency, usually refers to the use of radio frequency to read a small device (called Mark) on the information. The RFID system consists of three parts: a label, an interpreer and an antenna. Its working principle is as follows: the label into the field, RF signals received by the reader, by sending the obtained current energy out of the product information stored in the chips (Passive Tag, passive tags or passive tags), signal or take the initiative to send a frequency (Active Tag, active tags or active tags); the reader will read and decode the information, sent to the central information system on the data processing. RFID tags allow us to use radio waves to read and read multiple tags in batch and remote reading, which is far more meaningful than barcode. The same label not only includes anti theft function, but also can be used to prove the attribution of goods, provide the EAS system can achieve the function of electronic merchandise theft prevention, and use RFID can also achieve better purpose.
With the unification of RFID standards, RFID tags have been widely recognized and applied. The breakthroughs in recognition rate and stability, the realization of low cost labels, and RFID will take the place of EAS to dominate the market of electronic merchandise anti-theft.
Monobit recognition system used in the EAS system the main technology can be divided magnetic system, RF system, electromagnetic wave system. A single system with only two states, so it can only report items with or without the ability to report the item is what other details. The EAS system of different technologies is very different in product price, reading distance and reliability. The price of the RF label products used by electromagnetic wave system and radio frequency system is relatively cheap; the price of acoustic magnetic label is more expensive. Both have a soft label (a disposable label permanently attached to a commodity) and a hard label (reusable reusable burglar tag).
The acoustic magnetic system, the so-called Acoustic Magnetic (AM), is a resonance phenomenon produced by the tuning fork principle, which achieves almost zero false positives. The schematic diagram is shown in Figure 1. When the transmitted signal (alternating magnetic field) and the frequency of the acoustic magnetic label oscillation frequency is consistent, the acoustic magnetic label is similar to the tuning fork will cause resonance, resonance signals (alternating magnetic field); when the receiver detects 4-8 consecutive (adjustable) resonance signal (once every 1/50 seconds) after the receiving system will alarm. The characteristics of magnetic system is theft detection rate is high, almost zero false positives, without metal foil shielding, good anti-interference and protection of export (single set system wide width can protect 4 meters).
Radio frequency system (Radio Frequency, RF) uses radio wave as the signal for transmitting and receiving, the detection frequency is about 6~10 MHz, and the international common frequency is 8.2MHZ. The biggest advantage of the radio system is that the system cost is very low and the installation is convenient. However, because the tag is loop type and the frequency is relatively high, so the system is easily interfered by some items, such as cash registers, spotlights, cable lines and other electronic products and metal products, which may cause interference to the system, causing false alarm or no reporting.
Electromagnetic wave system (Electromagnetic System, ES) uses electromagnetic wave as the detection signal. The label of the electromagnetic wave system is small, the price of the label is cheap, and it can be repeated degaussing, but it is easily misreported by the influence of magnetic or metal material. Although radio frequency system is almost the same at the same time, but the price and technical reasons determine its acceptance in the market is not high, because of its label characteristics and price advantage, it is currently widely used in the domestic book market.
First of all, consider the quality of products: evaluate the performance index of EAS system, including system detection rate, system misreporting, anti environmental interference ability, shielding degree of metal, protection width, protection commodity category, anti-theft tag performance / size, degaussing equipment and so on.
Detection rate refers to the number of units of the effective label in different directions through the detection of the different location of the area of the alarm times.
As the labels of the anti-theft system are directionality, the concept of detection rate should be based on the average of the detection rate in the various directions. For the three most commonly used principles in the market, the detection rate of acoustic magnetic anti-theft system is the highest, usually more than 95%. The detection rate of radio / RF system is between 75-95%, and the detection rate of electromagnetic wave is generally between 50-70%. The detection rate is low, and the probability of missing report is large when the merchandise is taken out. Therefore, the detection rate is one of the main performance indicators to evaluate the quality of the burglar system. Of course, the detection rate is based on the good quality of the system. The detection rate of different commodity anti-theft system manufacturers will be very different. The installation spacing will also affect the detection rate.
The system misreport refers to the alarm of the non burglarproof tag trigger system. If there is a non label triggering alarm, it will bring difficulties to the staff's judgment and processing, or even the conflict between the customers and the shopping mall. Due to the limitation of the principle, the common EAS system can not completely eliminate the false positives, but the performance is different. The key to choose the system is to see the false positive rate.
3.Resistance to environmental interference
When the equipment is disturbed (mainly around the noise and interference power), system in the absence of any goods or by triggering the alarm after the alarm signal, this phenomenon is called false or ringing. Radio / RF system for vulnerability to environmental interference, often appear the ringing phenomenon, so some systems installed infrared devices, equivalent to the installation of an electric switch, only when the staff through the system, blocking the infrared system began to work, no one after when the system is in standby mode. Although this solution after the no ringing, but still can not solve the present situation after the people there.
The electromagnetic wave system is also easily disturbed by the environment, especially the interference of magnetic medium and power supply, which affects the performance of the system. Because of the unique resonance away from the acoustic magnetic system and intelligent technology, the system is automatically controlled by computer and software, and it can detect the ambient noise automatically. Therefore, it can adapt to the environment well, and has good ability to resist environmental interference.
4.The extent to which the metal is shielded
Many goods in shopping malls and supermarkets with metal objects such as metal foil packaged food, cigarettes, cosmetics, medicines and other commodities; and the metal itself, such as batteries, CD/VCD disc, hairdressing supplies, hardware tools, etc.; also the mall offers shopping cart, shopping basket, etc.. The influence of metal objects on the EAS system is mainly the shielding effect of the inductive tags, which makes the system detection device fail to detect effective labels or greatly reduces the detection sensitivity, which results in no alarm.
Radio / radio frequency RF system is the most seriously affected by metal shielding, which may be one of the main limitations of radio / radio frequency in actual use. The electromagnetic wave system may be affected by the metal objects, when detecting large blocks of metal into the electromagnetic wave system, the system will appear "stop" phenomenon, when the metal shopping cart, shopping basket was outdated, the goods inside even if there is a valid label, also because of shielding without alarm. In addition to the magnetic system of iron products such as iron, will be affected, the metal foil and other items / metal / shopping cart shopping basket supermarkets and other common items can work properly.
5.Width of protection
The shopping mall needs to consider the protection width of the anti-theft system, so as to avoid the narrow width between the supports and affect the customer's import and export. Besides, the shopping malls all want to make the entrance more spacious.
6.Protection of commodities
In general, the goods in the supermarket can be divided into two categories. One is the "soft" goods, such as clothing, shoes and hats, knitwear, this kind of commonly used hard labels, can be used repeatedly; the other is the "hard" goods, such as food, cosmetics, shampoo, the soft label protection for degaussing at the cashier, generally a one-time use.
7.Performance of anti-theft label
The anti-theft label is an important part of the whole electronic security system. The performance of the anti-theft label affects the performance of the whole system. Some labels are easily affected by damp and moisture. Some can not be bent; some labels can be easily concealed in the packages of merchandise, some will cover useful instructions and so on.
The reliability of degaussing apparatus and easy operation is an important factor in choosing anti-theft system. Degaussing equipment is more advanced at present are non contact type, it produces a certain height when the degaussing area, after the instantaneous effective degaussing label label, without touching the eraser, it is convenient for the cashier operation also speed up the checkout speed.
The organic combination of the security industry has been advocating for safety and defense, mainly for the commercial area of the EAS is no exception. EAS is unable to overcome the problem of false positives and false negatives, the retail industry is facing the customers when equipment alarm processing is particularly important and sensitive. As the EAS supplier, to provide users with the use of training, should explain unexpected situations may occur to the user, so that businesses in dealing with the alarm when the heart bottom; as a retailer, in the quality of training of employees should also be further improved, as human as possible to deal with all kinds of alarm, reduce the false positives of customers emotionally but the hurt; as a customer, need to understand the limitations of technology, with businesses to check, reduce disputes and unnecessary trouble. When the export companies in Europe and the United States order, usually with anti-theft tag; especially the European and American supermarket chain 100, most of them with 58kHz acoustic magnetic anti-theft system. With DR label only in the merchandise, to enter the European and American supermarkets. There are two kinds of hard and soft acoustic magnetic anti-theft tags. Nanjing richship electronic sound soft magnetic DR tags and LE tags in a series of two, the former consists of two pieces of vibrating plate and a base plate, which consists of a vibration film and a substrate composition, applied to clothing, shoes and hats, bags and packaging supplies / food etc.. The magnetic system has the ability of research and development is one of the few, Nanjing richship electronics is one of the more successful manufacturer of magnetic system of independent research and development, without grounding is the biggest highlight of the acoustic system.