CN103645523A - A reflection-type ellipsoid surface diaphragm - Google Patents

Abstract

The invention discloses a reflection-type ellipsoid surface diaphragm. The ellipsoid surface diaphragm is arranged on the inner wall of a light shield. The ellipsoid surface diaphragm is composed of one piece of straight ring diaphragm and several pieces of ellipsoid surface diaphragms. Compared with traditional annular diaphragms, the reflection-type ellipsoid surface diaphragm of the invention guarantees a performance of eliminating view field outer veiling glares, and at the same time, external heat fluxes can not directly irradiate the inner wall of the light shield. Most of rays of light which directly shine on the outer walls of diaphragm pieces of high reflection rates escape from a light-inlet through the reflection of a mirror plane, except that small amounts of the rays of light which directly shine on the outer walls of diaphragm pieces are absorbed and reflected diffusely, so that thermal loads of the inner wall of the light shield and the diaphragm are effectively reduced, and high temperature phenomenon of the inner wall of the light shield of a remote sensing camera under direct incidence of the sun are eliminated. In addition, the difficulty of thermal control of lens optical assemblies is reduced, so that a guarantee is provided for the imaging quality of the remote sensing camera.

Description

A kind of reflective ellipsoid light hurdle

Technical field

The present invention relates to a kind of ellipsoid light hurdle, particularly a kind of reflective ellipsoid light hurdle, belongs to space flight optical remote sensor technical field.

Background technology

Conventionally on remote sensing camera light shield inwall, can design the high-absorbility ring-shaped light hurdle of eliminating veiling glare outside visual field, this traditional ring-shaped light hurdle can significantly strengthen the black-body surface area of system light inlet again, and while making direct sunlight light shield inwall, its temperature sharply rises.The light shield of high temperature can pass through the temperature levels of radiation heat transfer appreciable impact primary mirror, secondary mirror and supporting construction thereof, causes optical texture distortion, has a strong impact on image quality; Meanwhile, light shield continuous high temperature has also significantly increased the infrared radiation of himself, and this main source of parasitic light in infrared spectral coverage imaging just.

To the disposal route of high temperature problem, be mainly to increase thermal capacitance or strengthen complement heat conduction.Increase thermal capacitance and be mainly by arranging that on light shield phase-change material realizes, yet geostationary orbit is because the cycle is longer, and light shield is subject to the solarization time long at night, and total thermoflux is large, need a large amount of phase-change materials to complete heat accumulation function, engineering construction feasibility is lower.Complement heat conduction is that light shield is carried out to samming, the heat of high-temperature area is evacuated to low-temperature region, as quadrature arrangement aluminium ammonia conduit heat pipe on light shield, design loop circuit heat pipe or fluid circuit device etc., but this kind of method increased extra weight, and day caused high-temperature area of icepro moves in time at light shield inwall, the aluminium ammonia conduit heat pipe of quadrature arrangement brings new problem to ground heat test, and loop circuit heat pipe and fluid circuit need extra driving power.

Summary of the invention

Technical matters solved by the invention is: overcome the deficiencies in the prior art, a kind of reflective ellipsoid light hurdle is provided, effectively reduce the load of light shield inner surface heat, reduced the high temperataure phenomena of light shield inwall when sun direct projection, possessed the ability of parasitic light outside good elimination visual field simultaneously.

Technical scheme of the present invention is: a kind of reflective ellipsoid light hurdle, be arranged in light shield inwall, by a slice, directly encircling light hurdle forms with several pieces ellipsoid light hurdles, wherein directly encircle light hurdle by straight-line segment as bus around the optical axis generation that rotates a circle, each ellipsoid light hurdle respectively by one section of elliptic arc line segment as bus around the optical axis generation that rotates a circle; Straight ring light field in the light inlet plane of space one side, after straight ring light hurdle, is arranged an ellipsoid light hurdle along light incident direction at interval of certain distance in light shield; High mirror face reflection coating is pasted over against space one side wall surface in straight ring light hurdle and several pieces ellipsoid light hurdles, and opposite side is high absorber coatings.

A summit of described straight ring light hurdle bus is positioned on the intersection of light shield internal face and light inlet plane, and another summit is positioned on the intersection of the logical light face of cylinder and light inlet plane, directly encircles light hurdle bus length l=R _o-R _i, R wherein _ofor light shield wall internal diameter, R _ifor logical light mouth external diameter.

The position of the 1st ellipsoid light hurdle bus and shape are determined by curvilinear equation below:

$\left\{\begin{array}{c}{x}^2/{R_O}^2+y^2/({R_O}^2-{R_I}^2)=1\\ R_I\≤x\≤R_O\end{array}\right.$

The 2nd position to N sheet ellipsoid light hurdle bus and shape are determined by curvilinear equation below:

$\left\{\begin{array}{c}{x}^2/{(Z_R/\cos {\mathrm{\θ}}_T-Z/\left(2\cos {\mathrm{\θ}}_T\right))}^2+y^2/({(Z_R/\cos {\mathrm{\θ}}_T-Z/\left(2\cos {\mathrm{\θ}}_T\right))}^2-{(Z/\left(2\cos {\mathrm{\θ}}_T\right))}^2)=1\\ Z/\left(2\cos {\mathrm{\θ}}_T\right)\≤x\≤Z_R/\cos {\mathrm{\θ}}_T-Z/\left(2\cos {\mathrm{\θ}}_T\right)\\ Z_R=Z(R_I+R_O)/(R_I+R_I)\\ {\mathrm{\θ}}_T=\mathrm{arctg}(R_I+R_O)/Z_R\end{array}\right.$

Wherein, equation coordinate system x axle overlaps with ellipsoid light hurdle bus major axis, y axle overlaps with ellipsoid light hurdle bus minor axis, x, y is respectively the transverse and longitudinal coordinate of any point on ellipsoid light hurdle bus, Z is that front a slice ellipsoid light hurdle bus is positioned at the vertical range that light inlet plane is arrived on the summit leading on the light face of cylinder, R ₀for light shield wall internal diameter, R _ifor logical light mouth external diameter.

Each ellipsoid light hurdle first focus of bus is all positioned on the intersection on light inlet plane and the logical light face of cylinder, and be fixed on all the time in same point, second focus of the 1st ellipsoid light hurdle bus is positioned at the summit place of straight ring light hurdle bus on the logical light face of cylinder, and the 2nd second focus to N sheet ellipsoid light hurdle bus is positioned at the summit place of its front a slice ellipsoid light hurdle bus on the logical light face of cylinder.Major axis summit is first focus and second focus line the joining that extends to light shield internal face.

Described distance between light incident direction ellipsoid light hurdle is by formula S=Z[(R _i+ R _o)/(R _i+ R _i)-1] determine, wherein Z is that front a slice ellipsoid light hurdle bus is positioned at the vertical range that light inlet plane is arrived on the summit leading on the light face of cylinder, R ₀for light shield wall internal diameter, R _ifor logical light mouth external diameter.

Described straight ring light hurdle and ellipsoid light hurdle are metal or non-metallic material, and wherein the high mirror face reflection coating on non-metallic material light hurdle is silver plated F 46 films; The high mirror face reflection coating on metal material light hurdle adopts silver plated F 46 films or metal surface polishing.

When the elliptic arc line segment of described ellipsoid light hurdle bus splices with several sections of straight-line segments, the high mirror face reflection coating on non-metallic material light hurdle adopts silver plated F 46 films or OSR sheet; The high mirror face reflection coating on metal material light hurdle adopts silver plated F 46 films or metal surface polishing or OSR sheet.

The present invention's technique effect is compared with prior art: the present invention directly encircles light hurdle by a slice and several pieces ellipsoid light hurdles form, be arranged in light shield inwall, compare with conventional circular light hurdle, the present invention is outside guarantee eliminating visual field in veiling glare performance, make outer hot-fluid cannot shine directly into light shield inwall, direct projection to the light of high reflectance light hurdle sheet outer wall except minute quantity be absorbed and diffuse reflection, the overwhelming majority is all by mirror-reflection effusion light inlet, effectively reduced the thermal load on light shield inwall and light hurdle self, eliminated the high temperataure phenomena of remote sensing camera light shield inwall when sun direct projection, reduced the thermal control difficulty of front lens optical assembly, thereby assurance is provided to the image quality of remote sensing camera.

Accompanying drawing explanation

Fig. 1 is one group of reflective ellipsoid light hurdle schematic cross-section;

Fig. 2 is oval mirror-reflection schematic diagram;

Fig. 3 is straight ring light hurdle and first ellipsoid light hurdle shape of generatrix and location;

Fig. 4 be the 2nd to N sheet ellipsoid light hurdle shape of generatrix and location;

Fig. 5 is the change curve that sun direct projection causes light shield inwall and light hurdle thermal load;

Fig. 6 is highest temperature light shield and light hurdle temperature cloud picture constantly; Wherein, (a) be light cylinder temperature cloud picture, (b) be the straight ring light hurdle temperature cloud picture of blackening process, (c) for adopting the straight ring light hurdle temperature cloud picture of OSR sheet, (d) being the ellipsoid light hurdle temperature cloud picture that ellipsoid light hurdle bus is spliced by 4 sections of straight-line segments, is (e) that ellipsoid light hurdle bus is by the ellipsoid light hurdle temperature cloud picture of 10 sections of straight-line segments splicings;

Fig. 7 is the earth light heat flow density curve that earth light secondary reflection arrives primary mirror.

Embodiment

The present invention is based upon on the basis of elliptic geometry characteristic and mirror-reflection principle.The light reflection principle of elliptic arc as shown in Figure 2, F ₁, F ₂for two focuses of spheroid, light passes through focal point F ₁, through any point A, B or C on spheroid, incident angle is θ _i, reflection angle is θ _r, reflection ray will inevitably pass through another focal point F ₂.If by one of them focal point F ₁be fixed on light inlet position, through ellipsoid, reflect back into light that S the orders light inlet of must overflowing.

By this principle, at light shield inwall, design one group of reflective ellipsoid light hurdle, be illustrated in figure 1 the schematic cross-section on one group of reflective ellipsoid light hurdle.Described reflective ellipsoid light hurdle directly encircles light hurdle by a slice and several pieces ellipsoid light hurdles form, light hurdle sheet is by glueing joint or the connected mode such as welding is fixed on light shield inwall, all smooth hurdles sheet is over against the uniform mirror face reflection coating that sets high of space one side surface, and opposite side is high absorber coatings.

Fig. 3, Fig. 4 directly encircle light hurdle and the 1st shape and Position Design schematic diagram to N sheet ellipsoid light hurdle sheet bus.

Straight ring light field is in light shield in the light inlet plane of space one side, and by straight-line segment, as bus, around optical axis CC, being rotated a circle and give certain thickness produces, and directly encircling summit of light hurdle bus is D, and another summit is F ₂, length

by light shield wall internal diameter R _owith logical light mouth external diameter R _idetermine,

Described ellipsoid light hurdle is arranged on light shield inwall successively, and monolithic ellipsoid light hurdle is rotated a circle and gives certain thickness around optical axis CC as bus by an elliptic arc line segment and produces.As first focal point F of ellipsoid light hurdle bus ₁all be positioned at logical light face of cylinder external diameter R _iplace, and be fixed on all the time on P point another focal point F ₂(F ₂', F ₂" ...) being positioned at the summit place of front a slice light hurdle bus on the logical light face of cylinder, major axis summit is focal point F ₁with F ₂(F ₂', F ₂" ...) line extend to the joining of light shield internal face.First summit of described ellipsoid light hurdle bus is positioned on light shield internal face, and the 2nd summit is positioned on the logical light face of cylinder.After two focuses of bus and the summit of a major axis are determined, its curvilinear equation and shaped position are determined by following formula:

Elliptic curve equation:

x ²/a ²+y ²/b ²=1

$f=\sqrt{a^2-b^2}$

For first ellipsoid light hurdle, under coordinate system shown in Fig. 3, set up following equation,

f=R _I

a=R _O

$b=\sqrt{{R_O}^2-{R_I}^2}$

Therefore the 1st ellipsoid light hurdle bus curvilinear equation is:

$\left\{\begin{array}{c}{x}^2/{R_O}^2+y^2/({R_O}^2-{R_I}^2)=1\\ R_I\&le;x\&le;{\mathrm{<figure-callout\; id="0"\; label="R"\; filenames="HDA0000419906000000022.png"\; state="\{\{state\}\}">R</figure-callout>}}_0\end{array}\right.$

Wherein 2a is transverse length, and 2b is ellipse short shaft length, and f is oval focal length.

For the 2nd, to N sheet ellipsoid light hurdle, in Fig. 4, under coordinate system, can set up following equation:

f=Z/(2cosθ _T)

a=Z _R/cosθ _T-f

$b=\sqrt{{(Z_R/\cos {\mathrm{\&theta;}}_T-f)}^2-{(Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2}$

Therefore the 2nd to N sheet ellipsoid light hurdle bus curvilinear equation is:

$\left\{\begin{array}{c}{x}^2/{(Z_R/\cos {\mathrm{\&theta;}}_T-Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2+y^2/({(Z_R/\cos {\mathrm{\&theta;}}_T-Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2-{(Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2)=1\\ Z/\left(2\cos {\mathrm{\&theta;}}_T\right)\&le;x\&le;Z_R/\cos {\mathrm{\&theta;}}_T-Z/\left(2\cos {\mathrm{\&theta;}}_T\right)\\ Z_R=Z(R_I+R_O)/(R_I+R_I)\\ {\mathrm{\&theta;}}_T=\mathrm{arctg}(R_I+R_O)/Z_R\end{array}\right.$

Wherein, in equation coordinate system, x axle overlaps with ellipsoid light hurdle bus major axis, y axle overlaps with ellipsoid light hurdle bus minor axis, x, y is respectively the transverse and longitudinal coordinate of any point on ellipsoid light hurdle bus, Z is that front a slice ellipsoid light hurdle bus is positioned at the vertical range that light inlet plane is arrived on the summit leading on the light face of cylinder, R ₀for light shield wall internal diameter, R _ifor logical light mouth external diameter.

Ellipsoid light column number amount is determined by light shield length.Along the distance between light incident direction ellipsoid light hurdle by formula S=Z[(R _i+ R _o)/(R _i+ R _i)-1] determine, wherein Z is that front a slice ellipsoid light hurdle bus is positioned at the vertical range that light inlet plane is arrived on the summit leading on the light face of cylinder.

All smooth hurdles in the present invention (comprising straight ring light hurdle and ellipsoid light hurdle) are metal or non-metallic material, and wherein the high mirror face reflection coating on non-metallic material light hurdle is silver plated F 46 films; The high mirror face reflection coating on metal material light hurdle adopts silver plated F 46 films or metal surface polishing.

In engineering reality, oval bus section, busbar section can splice with several sections of straight-line segments, and when the elliptic arc line segment of described ellipsoid light hurdle bus splices with several sections of straight-line segments, the high mirror face reflection coating on non-metallic material light hurdle adopts silver plated F 46 films or OSR sheet; The high mirror face reflection coating on metal material light hurdle adopts silver plated F 46 films or metal surface polishing or OSR sheet, OSR chip size is corresponding with straight-line segment size, the size of straight-line segment and OSR sheet is more tiny, spliced surface more meets light hurdle curved surface, be reflected the outer hot-fluid light of light inlet more, eliminate thermal load effect better.The specular reflectance size of coating determine to be reflected the outer hot-fluid light of light inlet number and eliminate the effect of thermal load.

Feature of the present invention is that outer hot-fluid light cannot shine directly into light shield inwall, utilize the principle of elliptic curve geometric properties and optical mirror plane reflection, direct projection to the light of light hurdle sheet outer wall except be seldom absorbed and diffusion, most by mirror-reflection effusion light inlet.

Table 1 has provided the physical attribute of light hurdle sheet and light shield wall in three kinds of contrast schemes that adopt two kinds of embodiments on ellipsoid light of the present invention hurdle and do not adopt ellipsoid light hurdle, and table 2 has provided thermal control coating attribute.Wherein arranging of light hurdle and light shield wall thickness guaranteed the consistent of embodiment and contrast scheme thermal capacitance.

Table 1 light shield wall and light hurdle sheet physical attribute

Table 2 thermal control coating radiation characteristic

Remarks: the regular reflectance of OSR sheet is taken as 0.9 times of total reflectivity

Fig. 5, Fig. 6, Fig. 7 be respectively change curve that on the geostationary orbit obtaining by UG NX software analysis, sun direct projection at night causes light shield inwall and light hurdle thermal load, night light shield inwall and light hurdle sheet occur that the highest temperature arrives the earth light heat flow density of primary mirror temperature profile, daytime constantly by sheet surface, light hurdle and light shield inwall secondary reflection.During calculating, choose Winter Solstice constantly, model absolute orientation, light inlet points to substar.While analyzing thermal load and temperature field, OSR sheet radiation characteristic is got 8 years end of lifetime values, and while analyzing outside visual field veiling glare, OSR sheet radiation characteristic is got initial value.During analysis temperature field, light shield outer wall is arranged OSR sheet.Outside visible spectrum visual field, the main source of veiling glare is the earth light on daytime, consider the relative capacity of only eliminating veiling glare outside visual field for comparing embodiment and contrast scheme, therefore only added up the earth light heat flow density that arrives light shield end disc central point by sheet surface, light hurdle and light shield inwall secondary reflection.

In embodiment 1, the oval bus section, busbar section on ellipsoid light hurdle is substituted with 4 sections of straight-line segments, in embodiment 2, the oval bus section, busbar section on ellipsoid light hurdle is substituted with 10 sections of straight-line segments, light hurdle sheet outer wall is all arranged OSR sheet.Result demonstration, in arrival embodiment 1, the thermal load mean value at night on light shield inwall and light hurdle is 155.2W, is respectively 51.6%, 38.1%, 46.7% of contrast scheme 1,2,3; In embodiment 2, thermal load mean value at night is 146.9W, is respectively 48.8%, 36.1%, 44.2% of contrast scheme 1,2,3.Embodiment 1 is respectively 9.1 ℃, 2.2 ℃ with embodiment 2 model maximum temperatures at night, and in contrast scheme 1,2,3 model maximum temperature at night respectively up to 53.4 ℃, 44.9 ℃, 45.6 ℃.Relatively by sheet surface, light hurdle and light shield inwall secondary reflection, arrive the earth light heat flow density of light shield end disc central point daytime, embodiment 2 minimums, next is contrast scheme 2, is the twice that embodiment 1(is about contrast scheme 2 again), be finally contrast scheme 3.

The above; only for a kind of embodiment of the present invention, but protection scope of the present invention is not limited to this, is anyly familiar with in technical scope that those skilled in the art disclose in the present invention; simple deduction or replace, within all should being encompassed in protection scope of the present invention.

The content not being described in detail in instructions belongs to those skilled in the art's known technology.

Claims (6)

1. a reflective ellipsoid light hurdle, it is characterized in that: be arranged in light shield inwall, by a slice, directly encircling light hurdle forms with several pieces ellipsoid light hurdles, wherein directly encircle light hurdle by straight-line segment as bus around the optical axis generation that rotates a circle, each ellipsoid light hurdle respectively by one section of elliptic arc line segment as bus around the optical axis generation that rotates a circle; Straight ring light field in the light inlet plane of space one side, after straight ring light hurdle, is arranged an ellipsoid light hurdle along light incident direction at interval of certain distance in light shield; High mirror face reflection coating is pasted over against space one side wall surface in straight ring light hurdle and several pieces ellipsoid light hurdles, and opposite side is high absorber coatings.

2. a kind of reflective ellipsoid light according to claim 1 hurdle, it is characterized in that: a summit of described straight ring light hurdle bus is positioned on the intersection of light shield internal face and light inlet plane, another summit is positioned on the intersection of the logical light face of cylinder and light inlet plane, directly encircles light hurdle bus length l=R _o-R _i, R wherein _ofor light shield wall internal diameter, R _ifor logical light mouth external diameter.

3. a kind of reflective ellipsoid light according to claim 1 hurdle, is characterized in that: the position of the 1st ellipsoid light hurdle bus and shape are determined by curvilinear equation below:

$\left\{\begin{array}{c}{x}^2/{R_O}^2+y^2/({R_O}^2-{R_I}^2)=1\\ R_I\&le;x\&le;R_0\end{array}\right.$

The 2nd position to N sheet ellipsoid light hurdle bus and shape are determined by curvilinear equation below:

$\left\{\begin{array}{c}{x}^2/{(Z_R/\cos {\mathrm{\&theta;}}_T-Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2+y^2/({(Z_R/\cos {\mathrm{\&theta;}}_T-Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2-{(Z/\left(2\cos {\mathrm{\&theta;}}_T\right))}^2)=1\\ Z/\left(2\cos {\mathrm{\&theta;}}_T\right)\&le;x\&le;Z_R/\cos {\mathrm{\&theta;}}_T-Z/\left(2\cos {\mathrm{\&theta;}}_T\right)\\ Z_R=Z(R_I+R_O)/(R_I+R_I)\\ {\mathrm{\&theta;}}_T=\mathrm{arctg}(R_I+R_O)/Z_R\end{array}\right.$

Wherein, equation coordinate system x axle overlaps with ellipsoid light hurdle bus major axis, y axle overlaps with ellipsoid light hurdle bus minor axis, x, y is respectively the transverse and longitudinal coordinate of any point on ellipsoid light hurdle bus, Z is that front a slice ellipsoid light hurdle bus is positioned at the vertical range that light inlet plane is arrived on the summit leading on the light face of cylinder, R ₀for light shield wall internal diameter, R _ifor logical light mouth external diameter;

Each ellipsoid light hurdle first focus of bus is all positioned on the intersection on light inlet plane and the logical light face of cylinder, and be fixed on all the time in same point, second focus of the 1st ellipsoid light hurdle bus is positioned at the summit place of straight ring light hurdle bus on the logical light face of cylinder, the 2nd second focus to N sheet ellipsoid light hurdle bus is positioned at the summit place of its front a slice ellipsoid light hurdle bus on the logical light face of cylinder, and major axis summit is first focus and second focus line the joining that extends to light shield internal face.

4. a kind of reflective ellipsoid light according to claim 1 hurdle, is characterized in that: described distance between light incident direction ellipsoid light hurdle is by formula S=Z[(R _i+ R _o)/(R _i+ R _i)-1] determine, wherein Z is that front a slice ellipsoid light hurdle bus is positioned at the vertical range that light inlet plane is arrived on the summit leading on the light face of cylinder, R ₀for light shield wall internal diameter, R _ifor logical light mouth external diameter.

5. a kind of reflective ellipsoid light according to claim 1 hurdle, is characterized in that: described straight ring light hurdle and ellipsoid light hurdle are metal or non-metallic material, and wherein the high mirror face reflection coating on non-metallic material light hurdle is silver plated F 46 films; The high mirror face reflection coating on metal material light hurdle adopts silver plated F 46 films or metal surface polishing.

6. a kind of reflective ellipsoid light according to claim 1 hurdle, is characterized in that: when the elliptic arc line segment of described ellipsoid light hurdle bus splices with several sections of straight-line segments, the high mirror face reflection coating on non-metallic material light hurdle adopts silver plated F 46 films or OSR sheet; The high mirror face reflection coating on metal material light hurdle adopts silver plated F 46 films or metal surface polishing or OSR sheet.

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