An integrated light guide plate (LGP) was designed for liquid crystal displays (LCD) without using prism and diffuser sheets. The integrated LGP is textured with micro-patterns on both the top and bottom surfaces. The textures effectively substitute for a single prism-sheet and a diffuser sheet in LCD displays without decreasing the brightness and uniformity. A LCD display with our integrated light guide is simulated to give average luminance of 4560 cd/$m^2$, luminance uniformity of 83% horizontal viewing angle $60^{circ}$ and vertical viewing angle $56^{circ}$. Therefore an ultra thin (slim) back light unit can be constructed with fewer optical sheets, which reduces the manufacturing cost and so improves price competitiveness.