Prismatic collimating device

A prismatic collimating device to collimate image bearing light, the prismatic collimating device comprising:

• a first prism and a second prism;
• the first prism comprising a first surface, a second surface, and a third surface,
• the first surface configured to receive and refract image bearing light, from an image source, towards the second surface,
• the second surface configured to reflect light by total internal reflection, the light received from the first surface, towards the third surface, and refract light received, from the third surface, towards the second prism, and
• the third surface configured to reflect light received, from the second surface, towards the second surface;
• and
• the second prism comprising a fourth surface, a fifth surface, and a sixth surface,
• the fourth surface configured to receive and refract light, received from the third surface, towards the fifth surface, and reflect light by total internal reflection, the light received from the fifth surface, towards the sixth surface,
• the fifth surface configured to receive light, from the fourth surface, and reflect towards the fourth surface, and
• the sixth surface configured to receive and refract light, providing a collimated output, received from the fourth surface;
• wherein the first surface, second surface, third surface, fourth surface, fifth surface, and sixth surface are optically powered, and an air gap is provided between the second surface and the fourth surface.