Face plate in transparent optical projection displays

A transparent optical projection display (3) for monitoring a display image (2), the display comprising:

• a combiner system (6);
• an image producing arrangement (8);
• and
• a device (1) comprising a fiber optic face plate (4), an analyzing unit, and an image sensor (5),
• wherein:
• the fiber optic face plate (4) comprises a first surface (4a) with optic fiber ends and a second surface (4b) with corresponding optic fiber ends and is adapted to transfer light from the first surface (4a) to the second surface (4b) through the optic fibers,
• the first surface (4a) abuts against a part (2a) of the display image (2) at a focused image plane (2b) and thus the light of the part (2a) of the display image (2) enters the optic fiber ends,
• the second surface (4b) is arranged to direct the part (2a) of the display image (2) to the image sensor (5), thereby translating/transferring the part (2a) of the display image (2) from the focused image plane to the image sensor (5), and
• the analyzing unit is configured to receive sensor data associated with the part (2a) of the display image (2) from the image sensor (5) and to analyze the sensor data to determine whether any errors exist in the part (2a) of the display image (2).

A method performed in a transparent optical projection display (3) for monitoring a display image (2), the transparent optical projection display comprising a combiner system (6), an image producing arrangement (8), and a device (1) comprising a fiber optic face plate (4), an analyzing unit, and an image sensor (5), the device being arranged for monitoring the display image (2), the method comprising the steps of:

• transferring (S1) at least one part (2a) of a display image (2) of the transparent optical projection display at a focused image plane (2b) to the image sensor (5) using the fiber optic face plate (4);
• and
• analyzing (S2) the sensor data of the at least one part (2a) of the display image (2) from the image sensor (5) using the analyzing unit,
• wherein the analyzing (S2) of the sensor data of the at least one part (2a) of the display image (2) comprises determining whether any errors exist in the at least one part (2a) of the display image (2).