Overall structure of LED shadowless lamp

Since the luminous efficiency of a single LED cannot meet the requirements of the light intensity and uniformity of the surgical shadowless lamp, it is necessary to use multiple LEDs to form an array, which should be reasonably arranged and evenly distributed so that the light intensity of each target plane meets the requirements, so as to determine the number and distribution rules of LEDs.

Although LED has high luminous efficiency and generates less heat, so many LEDs in a sealed box will still generate a lot of heat, and the temperature will even reach 60 ℃~80 ℃. Therefore, the radiator and heat dissipation channel must be reasonably designed to effectively reduce the thermal resistance of the system.

LED surgical shadowless lamp is composed of multiple lamp caps, in petal shape, fixed on the balance arm suspension system, with stable positioning, vertical or circular movement, and can meet the needs of different heights and angles during surgery. The whole shadowless lamp has 144 high brightness white LEDs, 8 of which are connected in series to form a group, which is called high brightness light-emitting diode (HBLEDs), and is composed of 18 groups in parallel. Each group is independent of each other. If one group is damaged, the others can continue to work, so it has little impact on the operation. Each group is independently driven by a LM3402 with constant current, and is controlled by a microprocessor (CMU) P89LPC932 with PWM pulse width adjustment, which can be steplessly adjusted. The current flowing through each LED is about 120~320 mA.