CN2109581U - Inverted image prism for large visual angle visual-shooting optical instrument - Google Patents

Abstract

The utility model discloses an inverted image prism for a large visual angle visual-shooting optical instrument. The utility model relates to an optical instrument with functions of visualization and visual-shooting, belonging to the field of applied optics. At present, the inverted image prism used in the light splitting-inverted image prism group of the visual-shooting optical instrument is a 45 DEG vitreous K9 rectangular prism. The included angle between an inner total reflection surface of the novel inverted prism described by the utility model and at least one adjacent grain side is from 47 DEG to 49 DEG. The light splitting-inverted image prism group can solve the problem that when the visual angle of the visual-shooting optical system to the virtual image of an eyepiece is bigger than 7.5 DEG, one side of the image has dark areas under the condition of preserving all advantages of the inverted image prisms. The inverted image prisms and the beam splitter prisms are ground together by one piece of glass.

Description

Inverted image prism for large visual angle visual-shooting optical instrument

The utility model belongs to the applied optics field, relates to the optical instrument that has visual and camera function simultaneously.

Be traditional visual optical instrument such as microscope, telescope, medical or technoscope install television pick-up equipment additional can make it in the bigger effect of aspects such as teaching, information record performance.For the structure of not destroying original visual optical instrument and keep visual function, when installing television pick-up equipment additional, often adopt following scheme: the luminous energy separated into two parts that with certain proportion eyepiece is penetrated with an Amici prism group of forming by two 45 ° of right-angle prisms, a part is passed Amici prism along the eyepiece optical axis direction and is entered human eye, and another part turns to after 45 ° of spectro-film reflections.This part light needs through an inverted image minute surface image planes mirror image reversal that tries again just can be entered image pickup optical system to obtain correct image.Usually with the inner total reflection face of 45 ° of right-angle prisms as the inverted image minute surface.Its advantage is to install and fix conveniently, no multiply-reflected image, and light energy losses is little.

Use 45 ° of right-angle prisms also to bring certain problem: usability is stable usually, and hardness is suitable, low-cost K9 glass processing prism.The refractive index of K9 glass is 1.5163, its inner total reflection angle be 41 ° 15 '.When converging ray and optical axis included angle greater than 3 ° of 45 ' times, also promptly when image pickup optical system to the visual angle of eyepiece virtual image largest contours greater than 7 ° of 30 ' times, a part of light of injecting inversion prism will not satisfy the inner total reflection condition and transmission will take place, this part light can not enter image pickup optical system, causes television image one side blanking bar to occur.Even the visual angle is not more than 7 ° 30 ', when its during near this critical angle, it will very harsh that the adjustment of prism and whole optical system is required, and be unfavorable for batch process.7 ° 30 ' the visual angle be not extreme case, the optical system of practical application be easy near or surpass this numerical value, therefore be necessary to address this problem.With high index of refraction soft glasss such as ZF1 processing prism critical visual angle is strengthened, but its easily the shortcoming of " fuel-displaced " (mouldy) hindered and be widely used; Plated film can be exempted the constraint of above-mentioned total reflection condition on fully reflecting surface, but will introduce about 10% energy loss.

Task of the present utility model is to propose the non-45 ° of inversion prisms of a kind of usefulness to solve the method that blanking bar appears in television image.

Taking all factors into consideration light energy losses, the chemical stability of optical element (mouldy) and factor such as easy to adjust is installed after, solving the method that blanking bar appears in television image is to start with from the inner total reflection condition that allows whole incident raies satisfy inversion prism.Below in conjunction with accompanying drawing the utility model is described in detail.

View in the middle of the accompanying drawing is a front elevation, and (4) are the eyepiece of visual optical instrument among the figure, and (6) are observer's eyes, and (1) (2) are two 45 ° of right-angle prisms, are coated with spectro-film on its 45 ° of cemented surfaces.(3) be inversion prism.Accompanying drawing top is upward view.The left side is a side view.Be divided into two parts at spectro-film from the light of eyepiece outgoing, a part enters human eye along former optical axis ejaculation prism (1) and is used for observing.Another part is reflected on spectro-film, enters inversion prism (3) through the interface of prism (2) and (3), and is penetrating after the generation inner total reflection on the inner total reflection face of prism (3), enters image pickup optical system (5) power supply and looks shooting.Still can satisfy the inner total reflection condition when selecting the corner angle α of prism (3) to make image pickup optical system be mapped on the inner total reflection face to the marginal ray at the maximum visual angle of observed image (the eyepiece virtual image), then the blanking bar on the television image is eliminated.The α angle should not be departed from 45 ° too much, in case cause other technical inconvenience.It is 47 °～49 ° that the utility model is got two equal corner angle α, and then corner angle β is 82 °～86 °.Prism grinds with K9 glass, the maximum visual angle that blanking bar do not occur can reach 11 ° 30 '～15 ° 30 '.Prism (2) and (3) can lump together with a glass and grind, to reduce by a cemented surface.A among the figure * B area is effective clear aperature of prism.

Use is the result show, this inversion prism can fundamentally be eliminated the picture blanking bar, and can reduce the requirement to prismatic adjustment mechanism greatly.As (2) and (3) are lumped together processing, also can simplify adhesive technology, favourable batch process.

Claims (2)

1, a kind of beam split-inversion prism that is used for visual-image pickup optical system is made up of Amici prism group and spectro-film, it is characterized in that: the angle of the adjacent logical light faceted pebble with at least one of the inner total reflection face of inversion prism is 47 °～49 °, and material is a K9 glass.

2, beam split-inversion prism according to claim 1, it is characterized in that: inversion prism can with two 45 ° of right angle Amici prisms in one be integrated, grind with a K9 glass, its inner total reflection face is 47 °～49 ° with the angle of a logical light face, also can have the Tp of two 47 °～49 ° of identical corner angle to glue together mutually with 45 ° of right-angle prism Amici prism groups with one.