"Black Technology" of Photocopy Fixing: What Amazing Secrets Does the High-precision Halogen Heating Lamp Hold?
Publish Time: 2025-07-22
In office equipment such as copiers and printers, heating lamps are the core components of the fixing unit, which directly affect the efficiency, stability and output quality of the equipment. With the iteration of technology, high-precision halogen heating lamps have gradually become the mainstream of the industry with their characteristics such as fast start-up, high efficiency and energy saving, and precise temperature control. This article will deeply analyze the technical value of copier halogen heating lamps from the dimensions of technical principles, structural innovation, performance advantages and industry applications.
1. Technical principles: synergistic effect of halogen cycle and infrared radiation
The core technology of halogen heating lamps comes from the "halogen cycle" mechanism. Traditional tungsten filament lamps are prone to blackening and shortening of lamp life due to tungsten evaporation at high temperatures. Halogen heating lamps fill the lamp tube with halogen gases such as iodine or bromine, so that the evaporated tungsten atoms combine with halogen to form tungsten halides, and then decompose into tungsten and halogen in the filament cooling zone, and tungsten atoms are redeposited on the surface of the filament. This cycle not only extends the life of the lamp (up to more than 5,000 hours), but also ensures the stability of infrared radiation - halogen lamps can convert more than 85% of the input electrical energy into infrared rays, which directly act on the toner on the copy paper to achieve efficient melting and fixing.
From the perspective of spectral characteristics, the color temperature of the halogen heating lamp is about 2500K, and its infrared radiation wavelength is highly matched with the absorption characteristics of the toner, so that the heat can be accurately transferred to the toner layer, reducing energy loss. For example, a certain A4-type double-tube halogen heating lamp uses a quartz tube with a diameter of 5.5mm and a built-in tungsten filament with a diameter of 0.2-0.4mm. Through the design of 19-35 light-emitting segments, the filament can be heated to 160℃ within 12.82 seconds, and the temperature rise rate reaches 12.42℃/s, which is far higher than the efficiency of traditional thermal radiation fixers.
2. Structural innovation: from single tube to double tube, from rigidity to flexibility
1. Double tube parallel design: improve power density and uniformity
Early copiers mostly used single tube heating lamps, which had heating blind spots and temperature fluctuations. Modern high-precision halogen heating lamps generally use a double tube parallel structure. By optimizing the distance between the lamp tubes (such as the distance between the two lamp tubes in a patented product is controlled at 3-5mm) and power distribution (single tube power 800-1200W, total power 1600-2400W), the temperature uniformity of the heating area is improved to within ±5℃. For example, a brand of copier fuser unit uses a double tube halogen lamp, with a polytetrafluoroethylene-coated heating roller, which can raise the fuser temperature from room temperature to 200℃ within 15 seconds to meet the needs of high-speed copying.
2. Flexible filament and support ring technology: solve the problem of thermal deformation
Halogen filaments are prone to droop or break due to thermal expansion at high temperatures. To solve this problem, the industry has developed a composite structure of flexible filament and support ring: the tungsten wire is wound into a spiral shape with a height of 0.6-1.0mm, and a tungsten wire support ring with a diameter of 3-4mm is embedded in the middle of the filament. For example, in a patented product, the filament consists of 35 light-emitting segments, the length of the central light-emitting segment is 3mm, and the lengths of the side light-emitting segments on both sides are symmetrically decreasing. After being fixed by the support ring, the filament can still remain straight at a high temperature of 250℃, avoiding contact with the inner wall of the quartz tube and causing a short circuit.
3. Optimization of porcelain head and wire: improving electrical performance and reliability
The porcelain head of the halogen heating lamp needs to withstand high temperature (up to 300℃) and high-frequency switching impact. Modern products use high-purity alumina porcelain heads, combined with molybdenum rod lead wires and copper wire metal strip packaging technology to reduce the contact resistance to below 0.1mΩ. For example, the ceramic head of a certain copier heating lamp has passed the high-voltage impact test (10kV/1min) and the thermal cycle test (-20℃ to 250℃/1000 times), ensuring stable operation in extreme environments.
3. Performance advantages: balance between efficiency, life and cost
1. Fast start-up and precise temperature control
The heat capacity of the halogen heating lamp is only 1/5 of that of the traditional nickel-chromium alloy heating wire. With the PID temperature control algorithm, the fixing temperature can be raised from the standby mode (150℃) to the working mode (200℃) within 5 seconds, and the temperature fluctuation is controlled within ±2℃. For example, after a high-speed copier adopts a halogen heating lamp, the first copy time is shortened from 12 seconds to 8 seconds, and the continuous copy speed is increased to 60 pages/minute.
2. Long life and low maintenance cost
Thanks to the halogen cycle mechanism and the high purity of the quartz tube (SiO₂ content ≥99.9%), the life of the heating lamp can reach more than 5,000 hours, which is 3-5 times that of the traditional tungsten filament lamp. Based on an average daily usage of 4 hours, the life of a single lamp exceeds 3 years, significantly reducing the frequency of equipment maintenance. In addition, the thermal shock resistance of the quartz tube (which can withstand rapid cooling and heating from -40℃ to 300℃) also reduces the risk of lamp breakage.
3. Energy saving and environmental benefits
The energy conversion efficiency of the halogen heating lamp is over 85%, which is 30%-40% energy-saving compared with the traditional thermal radiation fuser. Taking a certain model of copier as an example, after using halogen lamps, the annual power consumption of a single device is reduced from 1200kWh to 800kWh. Calculated at a commercial electricity price of 0.8 yuan/kWh, the annual electricity bill is saved by 320 yuan. At the same time, quartz tubes and tungsten filaments are 100% recyclable and meet RoHS environmental standards.
4. Industry application: expansion from office equipment to industrial manufacturing
1. Office equipment: the core of high-speed copying and color printing
In high-speed copiers, halogen heating lamps must meet the "on-the-go" requirements. For example, a certain brand of color copier uses a double-tube halogen lamp, combined with a hot-pressed fixing roller (surface coating hardness HRC58-62), which can achieve 0.1mm precision toner melting at a high temperature of 250℃, ensuring the saturation and layering of color images. In addition, by optimizing the distribution of the filament light-emitting segments (such as increasing the power density of the center segment by 20%), the curl rate of the paper after fixing can be reduced (from 3% to 0.5%).
2. Industrial manufacturing: heating engineering of semiconductors and solar cells
The high efficiency and controllability of halogen heating lamps make them widely used in the industrial field. For example, in semiconductor wafer processing, halogen lamp arrays (single lamp power 2000W) can achieve local heating through a mirror reflection system, with a temperature uniformity of ±1℃, meeting the requirements of photoresist curing. In solar cell production, halogen lamps are used in the sintering process, which can raise the temperature of silver paste from room temperature to 800℃ within 1 second to form a low-resistance conductive layer.
3. Special applications: Heating in vacuum environments and narrow spaces
The miniaturization (diameter 5.5mm, length 150mm) and vacuum compatibility (can work in 10⁻³Pa environment) of halogen heating lamps make them an ideal choice for special equipment. For example, in spacecraft thermal control systems, halogen lamps are used to simulate solar radiation and test the performance of materials under extreme temperatures; in medical equipment, halogen lamps are used for rapid disinfection of endoscopes, killing 99.9% of bacteria within 30 seconds at a high temperature of 250℃.
5. Future trends: integration of intelligence and integration
With the development of Internet of Things technology, halogen heating lamps are evolving from single heating elements to intelligent modules. For example, the "smart heating unit" launched by a certain company integrates temperature sensors, wireless communication modules and adaptive algorithms, which can monitor the status of the lamp tube (such as voltage, current, temperature) in real time and predict the remaining life through the cloud platform. In addition, flexible substrate halogen lamps (thickness 0.5mm) and miniaturized design (single lamp power 200W, volume reduced by 60%) also provide new solutions for portable devices (such as mobile printers).
High-precision halogen heating lamps have become core components in the fields of copiers, printers and industrial heating due to their technological advantages. From the dual-tube parallel structure to the flexible filament technology, from fast start-up to intelligent temperature control, every innovation is driving the improvement of equipment efficiency and reliability. In the future, with the integration of materials science and Internet of Things technology, halogen heating lamps will develop in a more efficient, intelligent and environmentally friendly direction, injecting new momentum into office automation and industrial manufacturing.
