OPTICAL SYSTEM OF ON-BOARD PROJECTION INDICATOR Russian patent published in 2024 - IPC G02B27/01 G02B27/10 

FIELD: avionics.

SUBSTANCE: optical system of the projection on-board indicator contains a combiner in the form of a beam-splitting concave spherical mirror installed at an angle to the sighting axis, a projection optical system and a display. The projection optical system is made of two optical modules separated by a prism with two reflective surfaces and a deflection angle of the sighting axis α₁. The first module is made of two positive centred lenses inclined around the top of the first lens. The second module is made of five lenses: the first is a biconvex hyperbolic lens offset from the sighting axis and tilted around the vertex, the second is a positive meniscus offset from the optical axis of the first lens and tilted around the vertex, the third is a negative meniscus offset from the axis of the second lens and tilted around the apex, the fourth is a biconvex lens offset from the axis of the third lens and inclined around the apex, the fifth is a positive meniscus offset from the axis of the fourth lens and inclined around the apex. Optical powers, displacements, and angles of inclination of the lenses satisfy the conditions specified in the claims.

EFFECT: flight safety due to a shield-free visibility zone of the pilot's observation space.

2 cl, 3 dwg