Detailed comparison and evaluation of two panel lamps

The LED panel is the best choice to replace the traditional lighting, such as soft, comfortable, comfortable lighting in the hospital.

LED panel lights have two types: side light and direct down (direct light), both need to be used with drive power supply.

The installation methods include embedded, surface mounted, hoisting and integrated ceiling installation.

There are three types of panel lights in total. One is small panel lamp, which can be regarded as downlight. The principle of light emission is that the light emitted by the side lamp bead transmits light from the light guide plate. It has square and round shape, the size is about 90mm ~ 225mm (diameter or side length), and the power can be 3W 6W 9W 12W 15W 18W 24W.

One is non-standard size, which is usually customized according to the customer's specific engineering and special size parameter requirements.

The first type is the conventional size, which has 300 * 300 mm, 300 * 600 mm, 600 * 600 mm, 300 * 1200 mm, 600 * 1200 mm, and some countries and regions have slight differences in size. For example, the size of 60 * 60 panel lamp is generally 595 * 595mm in China, 595 * 595mm in Europe, 600 * 600mm in Ecuador, 603 * 603mm in North America, 620 * 620mm in Germany and Brazil.

product mix

LED side light emitting panel light mechanism and luminous principle:

The structure of side light emitting LED panel lamp mainly includes frame, diffusion plate, light guide plate, light strip, reflective film back plate and so on

The light of LED lamp bead enters into the light guide plate from the light emitting surface, and then the light radiates downward after reaching the reflection point of the light guide plate. The light that does not reach the reflection point will be reflected back through the reflective film, so that most of the light of the LED lamp bead is converted into the light used for lighting. The quality of light guide plate is an important standard to measure the quality of side light-emitting panel lamp.

Side light emitting panel lamp

Structure and luminous principle of LED direct down panel lamp:

The structure of direct down (direct light emitting) panel lamp mainly includes the back cover of frame diffusion plate light bar (including aluminum substrate lamp bead lens). The light of LED lamp bead is scattered by lens and reflected by the back cover, which is emitted from the light emitting surface of the lamp.

Analysis of components of conventional panel lamp

1. Frame: the strength of frame affects the durability and the overall texture of lamps and lanterns

The frame is an important part of the panel lamp. The high strength frame makes the panel lamp more durable. The heat dissipation performance of LED panel lamp is different due to the different materials used. At present, the frame materials of panel lamp mainly include aluminum alloy, steel, PC, a6063, aluminum plastic, steel, etc. The most commonly used is aluminum frame (small panel lamp, useful plastic shell), and divided into splicing and welding frame, welding frame will be more solid, the price will be more expensive than splicing frame. General frame according to the style of flat frame, step box, the price will be different. In addition, the weight of the frame (the amount of material used) will also affect the price.

2. Lamp bead

It will also affect the brand, the quantity and the effect of the light. The commonly used lamp beads are smd2835 and smd4014, and the brands are Hongli, Sanan, sumsang and Lumileds (formerly Philips), and the price of the brand lamp beads will be more expensive. The number of lamp beads needed by direct down panel lamp is much lower than that of side light-emitting panel lamp because of its light-emitting beads scattered by optical lens. 

3. Diffusion plate: different materials have different transmittance

The main function of the material is to diffuse the light of PP and PC. Price from high to low, using more PS and PP.

Acrylic transmittance is 92%, PC is 88%, PS is probably 80%, acrylic material transmittance is higher than PC, and the cost is low, and its anti-aging performance is weak; and PC material price is expensive, but anti-aging performance is strong. In addition, the thickness of diffusion plate used by different manufacturers is different, and the price of 0.8mm-1.2mm thick is higher than that of the conventional one. The direct light-emitting panel lamp requires higher intensity of diffusion plate than that of side light-emitting panel lamp, and is generally thicker. 

4. Light guide plate: plate is a factor that has great influence on light efficiency except for lamp beads 

The light guide plate is a component of the side light-emitting panel lamp. The function of the light guide plate is to refract the light parallel to the direction of the light transmitting plate into the direction perpendicular to the light transmitting plate, and the light reflected from the light guide plate to the back of the panel lamp by the reflective paper. In this process, the light attenuation should be reduced as much as possible. Generally speaking, the light efficiency of light guide plate largely depends on the dot design, followed by the selection of plate (transmittance). The commonly used plates are PMMA (acrylic), MAS, PS. The price goes from high to low. PS and MAS will turn yellow after a long time of use. PS will last for about two years, and MAS will last for three years. It also depends on the climate of the area. Generally speaking, the time required for yellowing in hotter places will be shorter. If you want a 5-year warranty or higher light efficiency, you will basically use PMMA light guide plate. The size of light guide plate used by each factory is generally in the range of 1.6-3.0 mm, and the thicker the plate, the higher the price.

Comparison of yellowing in test environment (accelerated aging)

5. Tegmentum dorsalis

Commonly used is the iron back cover, thickness, weight, strength is different. The back cover of straight down panel lamp is thicker than that of side light-emitting panel lamp, and the back cover of straight down panel lamp will be sprayed with plastic, in addition to coloring, it is also for better reflection.

6. Driving power supply

According to the brand, voltage, isolation (more safe isolation) non isolation, with or without stroboscopic (which will affect whether the light of the lamp is photographed under the mobile phone or not), the price of functional requirements (such as dimming and color matching) and certification requirements will vary.

7. Pet prism plate

Anti glare is required (UGR < 19, no glare), prism plate or anti glare film should be added before the diffusion plate.

8. Installation accessories

Spring clasp lifting parts and surface mounted frames are generally selected according to the needs of different customers.

Advantages and disadvantages of direct and side emitting

The side light-emitting panel lamp has the advantages of beautiful and simple, luxurious atmosphere, uniform and soft light-emitting, ultra-thin thickness, and convenient installation and transportation. The disadvantage is that it is not easy to achieve high luminous efficiency. At present, the cost is very high when it is about 120lm / W. In addition, PS and MAS light guide plate panel light for a long time, there may be yellow.

The advantage of direct light-emitting panel lamp is that the technology and process are relatively simple, and the semi-automatic production line makes the labor cost lower. The brightness is sufficient and it is easy to achieve high luminous efficiency. At present, it can achieve 135lm / W, and the lamp will not turn yellow. The price has advantages compared with the side lighting. The disadvantage is that the lamp is thicker, and it seems that there is no side light-emitting panel. The high-grade lamp will increase the packing volume and freight. Because of the empty structure, compared with the side light-emitting panel lights, the transportation requirements are higher. Some straight down panel lights will have some dark areas at the edge of the frame, mainly the style of beveled back cover. At present, there is a right angle side style straight down panel lamp, no dark area, light uniformity is better.