To provide a white lighting unit using LEDs of R, G, and B, a reflection type liquid crystal display device, and a back light.

The lighting unit has the LEDs of the primary light colors of red, green, and blue and an LED driving means of generating white light by after-image effect by repeatedly blinking the LEDs of the primary colors in time series at a high speed, and the LED driving means adjusts LED voltages of the respective colors so that while the LEDs of red, green, and blue all illuminate, white light is composed, and drives the respective LEDs of the primary colors at a blinking speed of 180 times per second. The liquid crystal display device equipped with a reflection type liquid crystal panel using the lighting unit as its light source displays an image by modulating light beams of red, green, and blue projected by the lighting unit in time series at a drawing speed synchronized with the switching speed of light beams of red, green, and blue and can compose and display a full-color image by after-image effect.