RU2540135C1 - Imaging system - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: system comprises a first component - combiner, mounted at an angle to the optical axis of the system, a second component comprising a first biconvex lens and a second convex-concave lens, which are decentralised and inclined relative to the optical axis of the system, an emitting microdisplay mounted at an angle to the optical axis of the system, and an electronic information processing unit. The surfaces of the first component are biconical. In the second component, the second lens is divergent and there are additional third and fourth biconvex lenses. The first and second components are placed such that an intermediate image forms in between.

EFFECT: reduced offset of the combiner relative to the eye of the observer and the weight of the second component with high image quality.

4 cl, 3 dwg

Description

The invention relates to the field of optical instrumentation and can be used to create optical systems helmet-mounted displays, for example, for individual equipment of a fighter.

The imaging system is designed to create in the field of view of the observer an image that is considered by him at the same time as the environment. The combination of images is carried out due to a partially reflecting and partially transmitting element - a combiner, on which a spectro-splitting coating or a hologram is applied. The brightness of the created image should be sufficient for its perception against the background of the surrounding environment in bright sunlight.

A known optical system helmet-mounted collimator display (see patent RU 2353958 C1, IPC G02B 27/00, publ. 04/27/2009), which contains a combiner, a first beam splitter, a projection lens comprising two components, an aperture diaphragm located between these components , second beam splitter and image source. The main disadvantage of the system is the presence of a translucent mirror, which reduces the energy characteristics by four times.

Known optical system for helmet displays, described in patent US 5526183, IPC G02B 27/14, publ. 06/11/1996, which contains a combiner and a transmitting module, consisting of six lenses and a wedge. The disadvantages of this system include the complexity of the design of the transmitting module and its large overall dimensions.

The closest in technical essence to the claimed system adopted for the prototype is an imaging system for a helmet-mounted display (see patent WO 97/01123, IPC G02B 27/01, 17/00, published on 01/09/1997), including the first component - a combiner, the reflecting surface of which is an aspherical toroid, mounted at an angle to the optical axis of the system, the second component containing the first positive plano-convex lens and the second positive convex-concave lens, all surfaces of which are spherical, strongly decentered (by 16.8 mm) relative to the optical axis of the system and mounted to it at an angle, and a display also mounted at an angle to the optical axis. In the prototype scheme, there is no intermediate image between the first and second components and the combiner’s extension relative to the observer’s eye is 83 mm, while the light diameter of the lenses of the second component is more than 40 mm and the axis thickness is more than 12 mm.

Observation of the situation is carried out directly by the eye through the combiner, which works for transmission (in clearance). The light flux from the display passes through the second component, then it is reflected from the concave surface of the combiner and enters the eye of the observer.

The main disadvantages of the prototype include the large dimensions and mass of the second component, associated with the use of highly decentralized lenses and a significant removal of the combiner relative to the observer's eye, limiting the same field of view for the binocular version of the system.

The problem to which the invention is directed, is to reduce the offset of the combiner relative to the observer’s eye and the mass of the second component in the image formation system with high image quality.

This goal is achieved by the fact that in the imaging system containing the first component, made in the form of a combiner mounted at an angle to the optical axis of the system, the second component containing the first positive biconvex lens and the second convex-concave lens, which are decentered and tilted relative to the optical axis systems emitting a microdisplay installed at an angle to the optical axis of the system, and an electronic information processing unit, the surfaces of the first component are made biconical, in the second m second lens component is made negative and the program further includes third and fourth biconvex positive lens, wherein the first and second components are made and arranged so that an intermediate image is formed between them.

And also by the fact that in the second component, the first surface of the second lens is aspherical.

And also because in the second component the first surface of the third lens is aspherical.

And also the fact that in the second component the third and fourth lenses are decentered relative to the optical axis of the first and second lenses.

Figure 1 presents a diagram of an imaging system.

Figure 2 presents the path of the rays in the imaging system.

Figure 3 presents graphs of the function of energy concentration (FFE) in a circle of a given diameter, characterizing the quality of the imaging system.

The imaging system contains a first component — a combiner 1, whose surfaces are biconical, mounted at an angle α to the optical axis of the system, a second component containing a first positive biconvex lens 2, a second negative convex-concave lens 3, a third positive biconvex lens 4, and a fourth positive a biconvex lens 5 emitting a microdisplay 6 and an electronic information processing unit 7. In the second component, the first surfaces of the lenses 3 and 4 are aspherical. Lenses 2 and 3 are decentered relative to the optical axis by a value of b ₁ selected from the condition 0≤b ₁ ≤2 mm, and tilted by an angle β. Lenses 4 and 5 are decentralized relative to the optical axis of lenses 2 and 3 by a value of b ₂ selected from the condition 2≤b ₂ ≤4 mm. The microdisplay 6 is installed at an angle γ to the optical axis of the system.

The imaging system operates as follows. The signal from the observed scene from the optical-electronic device (for example, a thermal imager) is transmitted to the electronic information processing unit 7, which simultaneously receives service information. In the electronic information processing unit 7, a video frame is formed in which service information is added to the raster image. Then the resulting video frame is collapsed with the inverse distortion function of the optical system and transmitted to the emitting microdisplay 6. After that, the radiation passes through the lenses 5-2 of the second component, then it is reflected from the concave surface of the combiner 1, then the collimated radiation beam is sent to the eye of the observer. The observer sees the image coming from the emitting microdisplay 6, containing the image of the scene with service information superimposed on the image of the environment viewed through the combiner 1.

The layout of the optical system with the formation of an intermediate image made it possible to reduce the light diameters of lenses 2-5 of the second component to 22 mm, and their axial thickness to 8.5 mm, and thereby reduce its weight and dimensions.

Reducing the offset of the combiner 1 relative to the observer’s eye to 67 mm makes it possible to increase the field of view for the binocular version of the system and improves the ergonomic characteristics of the imaging system due to the optimal location of the center of mass.

In the inventive system, spherical aberration and astigmatism are well corrected due to the selected surface shape of the combiner 1 and an increase in the number of lenses in the second component, which is illustrated by graphs of the energy concentration function shown in Fig. 3. In the proposed image forming system, the correction of distortion occurs due to electronic compensation carried out by the information processing unit 7.

Thus, the implementation of the imaging system in accordance with the formula of the claimed materials can reduce the dimensions and weight by reducing the removal of the combiner relative to the observer’s eye and the dimensions of the second component with high image quality.

Claims (4)

1. An imaging system comprising a first component made in the form of a combiner mounted at an angle to the optical axis of the system, a second component containing a first positive biconvex lens and a second convex-concave lens that are decentered and tilted relative to the optical axis of the system, emitting a microdisplay, mounted at an angle to the optical axis of the system, and an electronic information processing unit, characterized in that the surfaces of the first component are made biconical in the second component Thoraya negative lens is formed, and further introduced third and fourth biconvex positive lens, wherein the first and second components are arranged so that an intermediate image is formed between them. 2. The system according to claim 1, characterized in that in the second component, the first surface of the second lens is aspherical. 3. The system according to claim 1, characterized in that in the second component, the first surface of the third lens is aspherical. 4. The system according to claim 1, characterized in that in the second component the third and fourth lenses are decentered relative to the optical axis of the first and second lenses.

Images