WO1988001418A1 - Procede et appareil de projection pour demontrer des phenomemes astronomiques - Google Patents

Procede et appareil de projection pour demontrer des phenomemes astronomiques Download PDF

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Publication number
WO1988001418A1
WO1988001418A1 PCT/DK1987/000102 DK8700102W WO8801418A1 WO 1988001418 A1 WO1988001418 A1 WO 1988001418A1 DK 8700102 W DK8700102 W DK 8700102W WO 8801418 A1 WO8801418 A1 WO 8801418A1
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WO
WIPO (PCT)
Prior art keywords
star body
spherical surface
representation
surface part
axis
Prior art date
Application number
PCT/DK1987/000102
Other languages
English (en)
Inventor
Leif Duelund
Ole Nielsen
Christian Petresch
Svend Westermann
Karl August THERNØE (deceased)
Original Assignee
Danmarks Lærerhøjskole
The Probate Court Of Lyngby (Legal Representative
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Danmarks Lærerhøjskole, The Probate Court Of Lyngby (Legal Representative filed Critical Danmarks Lærerhøjskole
Publication of WO1988001418A1 publication Critical patent/WO1988001418A1/fr

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Classifications

    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
    • G09B27/00—Planetaria; Globes

Definitions

  • the present invention relates to a method and a projecting apparatus for demonstrating astronomical phenomena. 5
  • Any elementary teaching in astronomy includes an explanation and/or illustration of the apparent movements or motions of the celestial bodies on the celestial sphere in dependency of the time and the geographical location of the observer.
  • Conventional educational material for use in teaching astronomy comprises graphic representations, 10 mechanical models and star globes.
  • all such conventional educational mate ⁇ rial suffers from serious deficiencies.
  • Such projecting apparatus may. comprise more than 120 projectors each comprising a light source, a condenser, and a projectable representation of one or more celestial bodies or other astronomical phenomena. Most of these projectors are also fitted with shutter stops for screening off the light from representations of the celestial bodies beneath the horizon. It is understood that the huge costs involved in building a planetarium can normally be justified only in rather few big cities of the world. There ⁇ fore, rather few universities and other educational establishments may benefit from the presence of a planetarium in the teaching of astronomy.
  • the present invention provides a method and apparatus by means of which the ap ⁇ parent motions or movements of celestial bodies on the celestial sphere or the firma ⁇ ment and other astronomical phenomena may be illustrated very realistically without necessitating investments of the same high order as those required in connection with 0 the establishment of a conventional planetarium.
  • the present invention provides a method of demonstrating astronomical phe ⁇ nomena, said method comprising projecting at least part of a first representation of fixed stars positioned on a first spherical surface part, onto a screen surface located 5 opposite to the centre of said spherical surface part, and rotating said first surface part about its centre in relation to said screen surface.
  • the motions or movements of the fixed stars and other fixed celestial bodies on the celestial sphere may be illustrated on the screen surface by performing a suitable rotational movement of the spherical surface part about its centre.
  • the representation of fixed stars may be projected onto the screen surface by arranging at least one light source on the concave side of the spherical surface part, and light beams passing from the light source, through said representation of fixed stars and to the screen surface, may then depict the fixed stars and other celestial bodies on the screen surface which may, for example, have a concave spherical shape with its centre substantially coinciding with the centre of said first spherical surface part on which the representation of the fixed stars is positioned.
  • said representation is projected onto a substantially plane screen surface by means of a first condenser having an optical axis which is arranged so as to extend substantially through the centre of said first spherical surface part and so as to extend substantially at right angles to said screen surface.
  • the condenser or lens system may then project a picture of a selected area or field of the first spherical surface part located immediately opposite to the con ⁇ denser, onto the screen surface despite the rotational position of the spherical surface part.
  • the method according to the invention renders it possible to simultaneously or successive ⁇ sively project representations of fixed stars or other celestial bodies from separate rotative surface parts onto a common screen surface.
  • at least part of a second representation of fixed stars positioned on a second spherical surface part is projected onto the screen surface so as to supplement a picture of fixed stars formed on the screen surface by the projection of the first representation.
  • the second representation may be projected onto the screen surface by means of a second condenser having an optical axis which is arranged so as to extend substantially through the centre of said second spherical surface part and so as to extend substantially at right angles to the plane screen surface.
  • Said first and second spherical surface parts may then be rotated in ⁇ dependently or synchronously about their respective centres so as to form a combined picture on the screen surface illustrating the apparent motions or movements of celes ⁇ tial bodies on a selected part of the celestial sphere or the firmament.
  • the condenser or lens may project a sharp picture onto the plane screen surface only if the representation of celestial bodies to be projected is located in a plane extending substantially through the focal point of the condenser and substantially at right angles to the optical axis thereof. Therefore, the representation of fixed stars or celestial bodies to be projected is preferably passed from the convex surface of said spherical surface part to the focal plane of the condenser by fibre optical light guiding means.
  • the representation of fixed stars located on one or more spherical surface parts may be used for illustrating the apparent motions of fixed stars and other fixed celestial bodies on a selected area of the firmament or celestial sphere.
  • the illustration provided in this manner may be supplemented by projecting a plurality of representations of other celestial bodies, including planets, the sun and/or the moon ' , onto the screen surface and by moving these representations along apparent orbits in relation to the projected fixed stars.
  • light effect generating means and/or light blocking means may be moved into projected light beams at a location between said spherical surface part and the associated condenser.
  • Such light effect generating means may, for example, be means for modifying the colour of the stars corresponding to the natural colouring by rising and setting, and means for providing natural sparkling or scintillation of the stars, and the blocking means may, for example, be moon occultation mearts for preventing stars, which are in fact covered by the moon, from being projected onto the screen surface.
  • the rotative movements of the spherical surface part or parts representing the fixed stars and other fixed celestial bodies, the movements of the representations of the non- fixed celestial bodies and the movements of the light effect generating means and/or the light blocking means should, of course, be controlled and interrelated so as to obtain a realistic representation of a certain section of the firmament or celestial sphere observed from a certain geographical location at a certain time.
  • These movements may be synchronized or interrelated in any suitable manner, for example by mechanical or hydraulic control means. In the preferred embodiment, however, the movements are controlled by means of an electric or electronic control device, such as a computer.
  • the present invention renders it possible to obtain a realistic dem ⁇ onstration of astronomical phenomena comparable with that obtainable in a conven ⁇ tional planetarium.
  • the conventional method used in a planetarium implies the existence of a special building forming a huge hemispherical projection screen while the method according to the invention may be performed in any large room where a plane projection screen is available, the method according to the invention is much more universally applicable for educational purposes. It is true that the total hemisphere of the celestial globe is depicted in a planetarium, while the method according to the invention only allows for depiction of a restricted section of the celestial sphere or globe when a plane screen surface is used.
  • the depicted celestial bodies not viewed in an absolute radial direction will appear to be more or less distorted, and only the viewer placed right in the centre of the hemispheri ⁇ cal screen may see ail of the depicted celestial bodies without distortion.
  • the representation of the celestial bodies is projected onto a plane screen surface in accor ⁇ dance with the method of the present invention, all of the observers or viewers are viewing the depiction of the celestial bodies in a single field without any distortions.
  • the field of the firmament depicted on the plane screen surface in the method according to the invention may be 60" in the horizontal direction and 45° in the vertical direction.
  • the projection of the representations of fixed stars and/or planets and other celestial bodies onto a plane screen surface renders it possible to depict various horizons and to obtain varying light effects, for example in connection with rising and setting of the sun or the moon.
  • different horizons which may, for example, include silhouettes of objects, such as pyramids, palm trees etc. indicating the geographical location of the observer, may be projected onto the screen surface by means of a separate projector.
  • This projector may include means for continuously changing the intensity and/or the colour of the projector light source so as to simulate the natural changes in light, for example by sunrise and sunset.
  • such "living horizon" is projected onto the screen by means of a separate horizon projector comprising a pair of first and second projecting lens systems having substantially parallel optical axes.
  • These first and second lens systems project a first and second horizon representation, respectively, onto the screen surface.
  • These first and second horizon representations have an identical horizon line or sky line separating the part defining the earth from the part defining the sky.
  • the sky part is made opaque and the earth part is transparent while in the second representation the earth part is made opaque and the sky part is transparent. It is understood that by controlling the intensity of the light emitted through the first and second lens systems it is possible to obtain that the horizon continuously looms up or fades out as desired.
  • interference light filters placed in each of the light beams projected by said pair of lens systems it is possible to simultaneously vary the colour of the light as desired.
  • the intensity of the light emitted through said first and second lens systems may be substantially the same to begin with whereafter the intensity may simultaneously be reduced for both lens systems, and the interference light filter in said second lens system may then continuously be turned so as to provide a reddish sky colour.
  • Sunrise may be simulated by substantially the reverse procedure.
  • the horizon representations may be in the form of slides, and a plurality of such slides may be positioned on a rotatable disc in a circular arrangement, and in this arrange ⁇ ment in which the representations are peripherally spaced, each belonging pair of representations may be positioned diametrically oppositely on the disc. A new pair of horizon representations may then be moved into the projecting position in the first and second lens systems by rotating said disc.
  • the present invention also provides a projecting apparatus for use in demonstrating astronomical phenomena, said apparatus comprising a frame, at least one star body mounted on said frame so as to be rotatable in relation thereto about a point, each star body including a representation of fixed stars, said representation defining a spherical surface part having its centre substantially coinciding with said point, a light source arranged at the concave side of said spherical surface part of each star body so as to project light through at least part of said representation, and means for rotatively moving each star body about said point.
  • the apparent motions of the fixed stars on the firmament or celestial sphere and changes from one field of the celestial sphere to another may then be obtained by rotating each star body about said point or centre.
  • the apparatus according to the invention may comprise a projecting condenser ar ⁇ ranged on the convex side of the spherical surface part and having an optical axis extending substantially through the centre of said spherical surface part so that the projected representation of fixed stars or other celestial bodies may be projected onto a substantially plane screen by means of the condenser.
  • the apparatus according to the invention may comprise fibre optical light guiding means for guiding light projected through said representation of fixed stars from the convex side of said spherical surface part to the adjacent focal plane of the associated condenser. Because the fibre optical light guiding means transfers the picture of the star representation on the spherical surface part into a plane surface substantially coin ⁇ ciding with the focal plane of the condenser or lens system, this condenser may project a sharp picture of the representation onto a plane screen.
  • the fibre optical light guiding means may be a block-shaped member including a huge number of glass fibres ex ⁇ tending substantially parallel in the direction of the optical axis of the projecting con ⁇ denser or lens system.
  • This block member which is preferably arranged stationarily in relation to the frame, preferably defines a concave spherical surface part which is ar- ranged closely adjacent to and is complementary with the convex surface of the spheri ⁇ cal surface part of the respective star body, and an oppositely positioned plane surface coinciding with said focal plane of the condenser.
  • the preferred embodiment of the appara ⁇ tus comprises first and second star bodies mounted rotat- ably about mutually spaced first and second points, respectively, and including first and second representations of fixed stars defining first and second spherical surface parts, respectively.
  • the optical axes of said first and second spherical surface parts are prefer ⁇ ably substantially parallel so that the projections of the first and second representations of fixed stars may supplement each other and define a unity.
  • This first and second representations may in combination represent only part of the celestial sphere or globe.
  • each of said first and second representations substantially defines a hemispherical surface part, said first and second representations defining in combination a representation of substantially the total celestial sphere or globe.
  • Each of the star bodies may then have a spherical outer surface divided into first and second hemispheres.
  • the first hemisphere may then be used for mounting and guiding means for rotatably mounting the star body about its centre, and the second hemisphere may define the representation of fixed stars.
  • the second hemisphere of the star body may comprise an opaque coating or layer having small light transparent openings or holes therein representing fixed stars or other fixed celestial bodies. These holes or openings may, for example, be made by means of laser light beams.
  • the light source may comprise a light source con ⁇ denser arranged at the concave side of the associated spherical surface part and having an optical axis substantially coinciding with the optical axis of the projecting condenser arranged at the convex side of the spherical surface part.
  • the light source condenser may then concentrate the light from the light source on the selected field of the representation of fixed stars, and, as explained above, this field may be changed by rotating the star body about the centre of the spherical surface part.
  • Each of the star bodies should be rotatably movable about any axis within certain limits.
  • said means for rotatably moving each star body about said point may comprise first means for rotating said star body about a first diametrical axis, second means for rotating said star body about a second diametrical axis extending at right angles to said first axis, and third means for rotating said star body about a third diametrical axis extending transversely to a plane defined by said first and second axes.
  • Any rotational movement of the star body about said point may be composed by rotational movement compo ⁇ nents about said first, second, and third axis, which means that any rotational move ⁇ ment may be obtained by suitably combining rotation of the star body about these three axes by means of suitable driving means.
  • said first axis is fixed in relation to the frame and substan ⁇ tially coincides with the optical axis of the projecting condenser.
  • Said first, second and . third rotating means may then comprise first, second and third driving rings surround ⁇ ing the associated star body and mounted on said frame so as to be independently rotatable about a common axis coinciding with said first axis, and first, second and third motors for independently driving said first, second and third driving rings.
  • the driving rings may then be drivingly connected to the star body in any suitable manner so as to rotate the star body about its respective axis.
  • the star body is mounted in said driving ring so as to be rotatable about said second axis which extends diametrically in relation to the first driving ring.
  • the second ring and the star body may then be drivingly interconnected by means of a suitable gear train caus ⁇ ing rotation of the star body about said axis when said first and second rings are ro ⁇ tated in relation to each other, while the star body is rotated about its first axis only when the first and the second rings are rotated at the same rotational speed.
  • the third driving ring and the star body may be drivingly interconnected by means of a gear train causing rotation of the star body about the third axis by rotation of the third ring.
  • the rotation of the star body about said third axis is dependent not only on the rotation of the third driving ring, but also on rotation of the first and second driving rings in accordance with equations defined by the specific embodiment of the gear trains and other force transmitting structure.
  • the guide means may comprise a guide member having an outer surface forming a spherical segment and defining in combination with the star body a hollow body, which has a substantially spherical outer surface and contains the light source.
  • One hemisphere of the hollow body may then have a transparent wall part on which the representation of fixed stars is positioned, while the other hemisphere of the hollow star body may be used for supporting and guiding the rotational movement of the star body.
  • Such guide means including said guide member may be mounted on the first driving ring and may also be mounted so as to be rotatable about said second axis. The rotation of the star body about said third axis may then be obtained by the star body being joumalled on said guide member about the third axis.
  • the light source is mounted so that the light therefrom is concen ⁇ trated about the optical axis of the projecting condenser despite the rotational position of the star body in relation to the frame. Therefore, in principle the light source could be mounted directly on the frame and be stationary in relation thereto. In the preferred embodiment, however, the light source is mounted within the hollow body, and in that case the light source may be mounted so that its orientation remains the same when the star body is rotated. Therefore, the light source may be mounted in said first ring so as to be rotatable about said second axis in relation to the star body, said second ring and said light source being interconnected by means of a gear train so as to prevent rotation of the light source of said second axis in relation to the frame.
  • the light source may then rotate together with the star body about the first axis coinciding with the optical axis of the projecting condenser, while rotation of the light source about the second axis is prevented.
  • the light source may be mounted on said guide member forming part of the hollow body whereby rotation of the light source about the third axis is also prevented.
  • the representation of fixed stars and other fixed celestial bodies on the spherical sur- face part of the star body may be of any suitable type securing a realistic and/or educa ⁇ tionally acceptable projection of part of the celestial sphere onto a screen.
  • at least the part of the star body defining the spherical surface part is made from a substantially transparent material, the representation of fixed stars being formed by an opaque coating arranged on the spherical surface part of the star body, the opaque coating having small openings or holes therein represent ⁇ ing fixed stars or other fixed celestial bodies.
  • Said opaque coating may comprise a layer of metal, such as chromium or copper, and a superposed layer of a photosensi ⁇ tive material, and the openings or holes therein may then be made by exposing the photosensitive coating to light, such as laser light, and to a subsequent etching pro ⁇ cess.
  • the diameters of the openings or holes may vary corresponding to the light inten ⁇ sity of the stars represented by the openings or holes. Such varying hole diameters may be obtained by emitting the exposing light beam through an adjustable diaphragm opening and by adjusting this opening corresponding to the desired star light intensity.
  • the representation of fixed stars may be obtained by forming holes or openings of very small varying diameters in a spherical wall part of a non-transparent material, such as metal, by any suitable method, for example by means of laser beams.
  • the correct mutual positions of the star defining openings or holes in the spherical surface part may be secured by using a computer program for controlling the hole preparing operations as well as for controlling the diameter of the diaphragm opening.
  • At least one of the planet projectors comprises a movable reflecting surface, such as a mirror, arranged so that the representation of the moving and/or variable celestial body is projected onto the reflecting surface.
  • the representation may then be reflected by the reflecting surface or mirror onto the screen, where the rep ⁇ resentation of the planet or other movable celestial body may be moved as desired by corresponding movement of the reflecting surface, for example about a pair of axes of rotation extending at right angles to each other, such as a horizontal and vertical axis.
  • the rotational movements of the star body or bodies and of the light reflecting surfaces of the planet projectors as well as the function of any other projecting means or light effect generating means may be controlled by an electric or electronic control device, such as a computer, in accordance with various programs which have been prepared for illustrating various astronomical phenomena or for illustrating a certain astronomical phenomenon in various manners.
  • FIG. 1 is a perspective view showing an embodiment of the projecting apparatus accord ⁇ ing to the invention projecting onto a screen
  • fig. 2 a front view of the apparatus illustrating how the star bodies are mounted in relation to each other in the frame, certain parts of the apparatus having been cut away
  • fig. 3 an enlarged front perspective view illustrating more detailed the mounting of one of the star bodies in relation to the frame, parts of the apparatus having been cut away for illustrative purposes
  • fig. 4 a rear perspective view corresponding to the front view shown in fig. 3, fig. 5 a front perspective view corresponding to that shown in fig. 3, further parts having been cut away so as to better illustrate the light source mounted within the hollow star body, fig. 6 a perspective view showing a moon projector of the apparatus shown in fig. 1 in
  • fig. 7 an exploded perspective view of the moon projector shown in fig. 6, fig. 8 a partly exploded perspective view of a sun projector corresponding to the moon projector shown in fig.7, and fig. 9 a fragmentary perspective view illustrating a displacably mounted star occultation
  • Fig. 1 shows a projecting apparatus generally designated reference numeral 10 for projecting representations of fixed as well as moving celestial bodies onto a plane screen 11 , whereby the apparent motions of celestial bodies and/or the changes of the
  • _ n stellations with time may be shown in a manner which is substantially the same or even better than in a conventional planetarium.
  • the apparatus 10 comprises a supporting frame or frame structure 12 on which a pair of mutually spaced hollow, substantially spherical star bodies 13 and 14 are mounted so that each spherical star body may be rotated about its centre. As best shown in figs.
  • each star body is divided into a first hemispherical part defining a representa ⁇ tion of fixed stars of the celestial sphere and a second hemispherical part used for mounting and driving the star body about its centre.
  • the upper star body 13 is divided into a first hemispherical part 15 defining the fixed stars and other fixed celestial bodies 16 of the northern celestial hemisphere, and a second hemispherical part 17 used for mounting, driving and guiding the star body 13.
  • the star body 14 is divided into a first hemispherical part 18 defining the fixed stars and other fixed celes- tial bodies 19 of the southern celestial hemisphere, and a second hemispherical part 20 used for mounting, driving and guiding the star body 14 as will be described more detailed below.
  • the first hemispherical parts 15 and 18 may comprise a thin shell of steel, copper or an other metal having small through holes therein defining the fixed stars 16 and 19 and formed e.g. by means of beams of laser light.
  • the hemispherical parts 15 and 18 may be made from a transparent material having an opaque coating or layer, and the fixed stars 16 and 19 may then be small openings or transparent dots or points in this layer.
  • the coating may be made from a metallic mate ⁇ rial, such as chromium or copper, and the points or openings representing the fixed stars may then be made by photogravure.
  • Each of the star bodies 13 and 14 contains a light source 21 (fig. 4), a reflector 22, and a condenser or lens 23 arranged about an optical axis 24 so that light from the light source 21 is projected towards the inner surface of the respective star body 13 or 14 around the optical axis 24.
  • the light source 21 is surrounded by a cooling jacket 25 which is connected to a vacuum source (not shown) through, connecting tubes 26, 27, and 28, and through flexible tubes or hoses 29 (fig. 1), whereby cooling air may be caused to flow through the cooling jacket 25.
  • the light source 21 , the reflector 22, and the condenser 23 are interconnected by means of a tubular mounting member 30 so as to form a unit which is rotatably mounted about an axis b which extends at right angles to the optical axis 24 and passes the centre of the spherical star body 13 or 14 as will be described more detailed below.
  • Electrical power may be supplied to the light source 21 through an electrical cable 31 and a sliding contact 32 (fig. 3).
  • a fibre optical block 33 is arranged adjacent to the outer surface of each of the star bodies 13 and 14 opposite to the condenser 23 and around its optical axis 24.
  • Each fibre optical block 33 is mounted fixed in relation to the frame 12 on a vertically extend ⁇ ing mounting plate 34 and has a concave side surface, which is complementary to and arranged very closely adjacent to but not in contact with the outer spherical surface of the associated, rotatably mounted star body 13 or 14.
  • the opposite side surface of the block 33 is a plane surface, and the block 33 is located so that this plane surface sub ⁇ stantially coincides with the focal plane of a projecting condenser or lens system 35 having its optical axis coinciding with the optical axis 24 of the condenser 23.
  • the projecting condensers 35 are adjustably mounted on a mounting plate 36 fixed on the frame structure 12.
  • the fibre optical brocks 33 may be made from sintered optical glass fibres (about 40,000 per mm 2 ) which extend parallel to the optical axis 24, and each of these glass fibres functions as a fibre optical light guide means. Therefore, the pattern of luminous openings or holes 16 or 19 in the field or section of the outer surface of
  • the star body 13 or 14 covered by the block 33 is transferred from the spherical side surface of the block 33 to the plane side surface positioned in the focal plane of the projecting condenser 35.
  • the pattern of light spots present in the focal plane of the condenser 35 will be projected onto the screen 11.
  • each of the blocks 33 could cover a total hemisphere of the star body 13 or 14. This would, however, give
  • each block 33 covers a spherical section extending over about 60° horizontally and about 45° vertically, and the limit of the picture projected onto the screen may be finally
  • the picture projected onto the screen 11 may be modified by means of light covering wedge members 37 (only one shown in fig. 1) which a e mounted on a mounting plate 38.
  • a circular opening 39 is formed around the optical axis 24 of each of the projecting
  • the wedge 37 which may be of a transparent, red-coloured material, may be displaced in relation to the mounting plate 38 so as to more or less cover the associated opening 39 whereby the light proj ⁇ ected onto the screen may be made more or less reddish so as to colour and weaken the light of stars which are rising and/or setting.
  • a plate-like occultation member 40 is
  • the occultation member which is made from glass or an other transparent material is ar ⁇ ranged closely adjacent to the plane side surface of the block 33 and has one or more light blocking occultation dots 165 (fig. 9) thereon for occluding light rays from star representations which should not be present on the screen 11 , e.g. in order to prevent Q fixed stars from being visible at a position within the sickle moon where they should have been hidden by the moon.
  • Vertically and horizontally extending threaded shafts 166 and 167 engage with nut members 168 and 169, respectively. These nut members are mounted on the occultation member 40, and the threaded shafts 166 and 167 may be rotated by respective step motors 170 and 171 which are mounted on the mounting
  • occultation dot may be moved vertically and/or horizon ⁇ tally in its own plane by energizing one or both of the motors 170 and 171. Sparkling or scintillation means (not shown) for providing a star sparkling effect may also be mount ⁇ ed on the. mounting plate 38 or at any other suitable position.
  • the projecting apparatus shown in fig. 1 also comprises a moon projector 41 , a sun projector 42 and a number of planet projectors 43 of which four are shown in fig. 1. These projectors are able to project light spots simulating the moon, the sun, and the planets, respectively, onto the screen 11 , and to move these light spots in relation to the screen 11 and to the representation of fixed stars projected thereon so as to simu ⁇ late the apparent motions or movements of these celestial bodies along their orbits on the celestial sphere.
  • the movements of the rotatable star bodies 13 and 14, which in combination represent the total celestial sphere, are interrelated so that the pictures projected onto the screen 11 by the two projecting condensers or lens systems 35 define a coherent field or section of the celestial sphere.
  • the movements of the star bodies 13 and 14, the projectors 41 , 42, and 43, the light colouring wedge members 37 and the occultation members 40 and other functions of the projecting apparatus may be controlled by means of an electric or electronic control device or computer 44 in accordance with various programs or commands.
  • Such programs may be selected and such commands may be given by means of a keyboard 45 which is electrically connected to the computer 44 by means of a cable 46.
  • the computer 44 may be electrically connected to various devices of the projecting apparatus by means of cables 47 so that the computer 44 and its keyboard 45 may be arranged distant from the projecting apparatus, if desired.
  • each of the star bodies 13 and 14 is mounted so that it may be rotated in relation to the frame in any direction about its own centre or about any axis passing that centre.
  • the rotative mounting of the upper star body 13 will now be de ⁇ scribed in detail with reference to figs. 2-5.
  • the mounting of the lower star body 14 is similar to that of the upper star body 13 and will therefore not be explained in detail.
  • the spherical star body 13 is mounted on the frame 12 by means of three coaxial driving rings 48, 49, and 50 having their common axis a coinciding with the optical axis 24 of the condensers 23 and 35.
  • Each of the driving rings 48-50 has an annular chan ⁇ nel 51 formed in its outer peripheral surface. The bottom and side surfaces of this channel 51 form race surfaces for a number of rollers 52 and 53, respectively, vide fig. 3.
  • rollers 52 and 53 are mounted in roller units 54, each comprising one of the rollers 52 which is rotatable about an axis parallel with the common axis 24 of the rings 48-50 so as to roll on the bottom surface of the associated channel 51 , and two of the rollers 53 which are rotatable about radially extending axes and which are rolling on the opposite side surfaces of the associated channel.
  • the roller units 54 which are periph ⁇ erally spaced around each of the driving rings, are stationarily mounted on an arch structure 55 which surrounds the respective driving ring and forms part of the frame structure 12.
  • the driv ⁇ ing rings 48, 49 and 50 may be rotated by means of step motors 56, 57 and 58, respectively, each having a through-going driving shaft 59 with a worm screw 60 at each end (figs. 2-4).
  • Each worm screw 60 is journalled in a mounting bracket 61 (fig. 4) which is fixedly mounted on the associated arch structure 55 and is in engagement with a worm gear toothing 62 formed on the outer periphery of the associated driving ring 48-50.
  • each of the driving rings may be rotated by energizing the associated step motor.
  • the star body 13 is mounted rotatably by means of journals 63 which extend outwardly from the star body in a diametrical direction and substantially in the plane separating the first and second hemispherical parts 15 and 17.
  • the journals 63 also extends diametrically in relation to the driving ring 49 and is rotat ⁇ ably mounted in bearing blocks 64 fixedly mounted on the inner surface of the driving ring 49 at diametrically opposite positions. Consequently, the star body 13 is rotatable in relation to the driving ring about the axis b of the journals 63.
  • the stationary sliding contact 32 is engaging with a pair of axially spaced contact rings 65 which are mount ⁇ ed on the outer side of the driving ring 49 and embedded in electrically insulating mate ⁇ rial 66, whereby electric power may be supplied to the light source 21 despite the rota ⁇ tional position of the star body 13.
  • the driving ring 48 is drivingly interconnected with the star body 13 by means of a gear train comprising a toothing 67 formed on the inner peripheral surface of the driving ring 48, a pair of gears 68 and 69 fixedly mounted on opposite ends of a shaft 70 which is journalled in a bearing fixed to the inner side of the driving ring 49 in a manner not shown, and a gear 71 fixedly mounted on one of the journals 63.
  • a gear train comprising a toothing 67 formed on the inner peripheral surface of the driving ring 48, a pair of gears 68 and 69 fixedly mounted on opposite ends of a shaft 70 which is journalled in a bearing fixed to the inner side of the driving ring 49 in a manner not shown, and a gear 71 fixedly mounted on one of the journals 63.
  • these gears may be spiral gears.
  • the star body 13 may be rotated about the axis a of the driving rings 48, 49 and 50 and about the optical axis 24 coinciding therewith by energizing the motor 57 so as to rotate the driving ring 49 about its axis a. If the driving ring 48 is simultaneously rotated by means of t e motor 56 and at the same rotational speed, the gears,68 and 69 will not rotate in relation to the driving rings 48 and 49, and the star body 13 will not be rotated about its axis b. If, however, the driving rings 48 and 49 are rotated at different rotational speeds, or if the driving ring 49 is not rotated, the star body will be rotated about the axis b.
  • a lower spherical segment 72 shown in figs. 3 and 4 is mounted stationarily in relation to the driving ring 49 by means of mounting devices 73, while the upper part of the star body 13 comprising the first hemispherical part 15, and a spherical annular member 74 are mounted rotatably in relation to the lower spherical segment 72 about an axis c which extends transversely to the plane defined by the axes a and b.
  • Guiding rollers 75 are rotatably mounted on arms 76 fastened to the gear 71 and to a mounting member 77, which is mounted on the jour ⁇ nal 63 arranged diametrically opposite to the gear 71.
  • These guiding rollers 75 are engaging with an outwardly open, peripherally extending annular channel 78 formed in the outer surface of the lower spherical segment 72 so as to guide the rotational move ⁇ ment of the upper part of the star body 13 about the axis c and so as to allow simul ⁇ taneous rotation of the gear 71 and of the star body 13 about the axis b.
  • a side surface of the driving ring 50 is provided with a gear toothing 79, and the lower spherical. segment 72 of the star body 13 is provided with a peripherally extending worm gear toothing 80.
  • the gear toothing 79 on the driving ring 50 is drivingly interconnected with the worm gear toothing 80 on the spherical annular member 74 by means of a gear train.
  • This gear train comprises a small gear 81 and a pinion 82 mounted on either end of a shaft 83, bevelled gears 84 and 85, which are arranged on a common shaft 86 and a bevelled gear 87 arranged at one end of a worm screw 88.
  • the small gear 81 is meshing with the toothing 79
  • the gear 82 is meshing with the gear 84
  • the gear 85 is meshing with the gear 87
  • the worm screw 88 is meshing with the toothing 80.
  • Each of the shafts 83 and 86 as well as the worm screw 88 have their axes extending at right angles to each other as shown in fig. 4, and they are all journalled in bearing means mounted fixedly in relation to the driving ring 49 and to the lower spherical segment 72 of the star body 13.
  • the driving ring 50 When the motor 58 is energized, the driving ring 50 is rotated. Rotation of the driving ring 50 causes rotation of the gears 81 , 82, 84, 85 and 87 and of the worm screw 88, whereby the upper part of the star body 13 including the first hemispherical part 15 is rotated about the axis c.
  • the rotational movement of the upper part of the star body about the axis c is not only dependent on the rotational movement of the driving ring 50, but also on the rotational movements of the other driving rings 48 and 49.
  • the moving means of the two star bodies 13 and 14 are substantially identical. As best shown in fig. 2 these star bodies are arranged substantially symmetrically about a horizontal plane, and the movements of the two star bodies are synchronized in that the same step motors 56, 57 and 58 are used for simultaneously rotating both of the star bodies 13 and 14.
  • the light source 21, the reflector 22, and the condenser 23 may be rotated together with the star body 13 about the axis a coinciding with the optical axis 24.
  • the light source unit As the light source unit is fixed in relation to the lower spherical segment 72 of the star body 13, the light source unit cannot be rotated about the axis e.
  • measures should be taken . to prevent the light source unit, including the light source 21 , the reflector 22, the condenser 23 and the tubular mounting member 30 from rotating about the axis b together with the star body.
  • the tubular mounting member 30 and, consequently, the total light source unit are mounted rotatably about the axis b by means of bearing discs 90 (fig. 5) fastened to the mounting member 30 and each cooperating with a bearing disc 91 which is stationarily mounted on the inner side of the lower spherical segment 72 of the star body 13, e.g. by means of screws or bolts 92 of which only one is shown in fig. 5.
  • Gears 93 and 94 of the same size and type are mounted so as to be rotatable about the axis b, and they are fixed to the gear 71 and to the bearing disc 90, respectively.
  • the gears 93 and 94 are drivingly interconnected by a shaft 95 having small gears 96 and 97 mounted at either end.
  • gears 96 and 97 mesh with the gears 93 and 94, respectively.
  • the shaft 95 is rotatably mounted on the lower spherical segment 72 of the star body 13.
  • the gears 96 and 97 will rotate the gear 94, and, consequently, also the light source unit the same angle in the opposite direction which means that the optical axis of the light source and condenser unit will remain coincid ⁇ ing with the axis a which is also the optical axis of the projecting condenser 35.
  • each projector comprises a light source 98 arranged in the bottom part of the projector, a device 99 for forming a representation of the celestial body in question, a condenser or lens system 100, and an upper light reflecting device 101.
  • the mirror 102 is mounted in an upper part 103 of a tubular projector housing 104.
  • the mirror 102 is mounted in a mirror holder 105 which is rotatably mounted in said upper part 103 about a substan- tially horizontal axis by means of pivot pins 106.
  • a sector shaped arm 107 is fixedly mounted on one of these pivot pins outside the housing 104 and has a worm gear toothing 108 formed thereon. This toothing is meshing with a worm gear 109 which is rotatably mounted on a bracket 110 fastened to the outside of the housing 104.
  • a bevelled gear 111 mounted at one end of the worm gear 109 is meshing with a bev- elled gear 112 mounted on the driving shaft of a step motor 113, It is understood that the mirror 102 may be tilted about a horizontal axis by energizing the motor 113.
  • the remaining part of the housing is rotatably mounted about its axis 115 in relation to the lower part 114 by means of a bearing structure 116.
  • the rotatable part of the housing 104 may be moved by means of a step motor 117 having mounted on its driving shaft a worm screw 117a (fig. 6) meshing with an outer worm toothing 118 formed on the projector housing to be rotated.
  • the rotating part of the housing 104 is supported by a cradling device 119 which is fixed on and forms part of the frame structure 12.
  • the representation of a celestial body projected onto the screen 11 by means of any of the projectors 41 , 42 and 43 may be moved along a desired orbit on the screen by rotating the projector housing 104 about its axis 115 by means of the motor 117 and by tilting the mirror 102 by means of the motor 113.
  • Fig. 7 shows the device 99 of the moon projector 41 shown in fig. 6 in more detail.
  • the device 99 for forming a representation of the moon comprises a tubular cylindrical member 120 having at its upper end an internal toothing 121 meshing with a gear 122.
  • An inverted cup-shaped member 123 has a disc 124 rotatably mounted at its upper end surface. In the mounted condition, the cup-shaped member 123 is nested over the cylindrical member 120, and the gear 122 is coaxial with and drivingly connected to the disc 124 which means that rotation of the cylindrical member 120 in relation to the cup- shaped member 123 causes rotation of the gear 122 and of the disc 124 in relation to the cup-shaped member 123.
  • the disc 124 includes a circular arrangement of a num ⁇ ber of moon pictures showing the moon in a number of different phases. In fig. 7 only twelve such moon pictures are shown. Normally, however, this number is much higher, e.g. as high as eighty.
  • the circular arrangement of the moon pictures is such that any of these pictures may be centred around the central axis 115 of the projector by rotat ⁇ ing the disc 124.
  • An inverted disc-shaped member 126 has a small central opening 127 defined in its upper end wall. This opening may include a picture of the surface contour of the moon.
  • Each of the members 120, 123 and 126 has an outer worm gear toothing 128, 129 and 130, respectively, each meshing with a worm gear 131 , 132 and 133, respectively, and as shown in fig. 6 these worm gears may be driven by step motors 134, 135 and 136, respectively.
  • a lug 137 projecting radially from the outer peripheral surface of each of the members 120, 123 and 126 cooperates with a fixedly mounted indicator 138 for use in calibrating and controlling of the operation of the projector.
  • Such indicator may, for example, comprise a light diode and an oppositely located photo transistor mounted so that in a certain position of the lug 137 light from the diode is blocked by this lug.
  • the moon picture 125 or moon phase relevant in a certain situation may be selected by energizing the motor 134 so as to rotate the disc 124.
  • a correct orientation of the moon picture chosen may be obtained by energizing the motor 135 so as to rotate the cup-shaped member 123 on which the disc 124 is mounted.
  • the disc-shaped member 126 may be rotated by energizing the motor 136, and thereby it is possible to orientate the surface contour of the moon dependent on the geographical position from which the moon is observed.
  • the device 99 further comprises a film unit 139 which comprises a box-shaped housing 140 in which three film transporting rollers 141, 142, and 143 are rotatably mounted. Each of these rollers is driven by a step motor 144, 145 and 146, respectively. The ends of a film 147 are wound around the rollers 141 and 143, and the film is kept in a tightened condition by the motors 144 and 146. From the roller 143 the film is passed under a tightening roller 148, above the transporting roller 142, and beneath a film guiding block 149 having a transversely extending slot 150 registering with the central projection axis 115.
  • a film unit 139 which comprises a box-shaped housing 140 in which three film transporting rollers 141, 142, and 143 are rotatably mounted. Each of these rollers is driven by a step motor 144, 145 and 146, respectively. The ends of a film 147 are wound around the rollers 141 and 143, and the film
  • a screw member 151 extending at right angles to the film 147 is passed through and is in engagement with a threaded bore formed in the block 149.
  • the screw member 151 may be rotated by a step motor 152.
  • the moon picture proj ⁇ ected along the central axis 115 through the slot 150 may be modified in various respects in the unit 139.
  • a black spot 153 on the film may be moved into the projected moon picture for providing eclipse of the moon, the moon light may be reduced or coloured by means of a toned or coloured field 154, and a part of the moon positioned below the horizon may be covered by means of a black triangular field 155 on the film 147.
  • the various fields of the film may be moved into the light beam pass ⁇ ing through the slot 150 by moving the film by means of the motors 144, 145 and 146 and/or by moving the unit 139 in a transverse direction by rotating the screw member 151 by means of the motor 152.
  • the sun projector corresponds in many respects to the moon projector, and correspond- ing parts in figs. 6, 7 and 8 are designated the same reference numerals.
  • the dish-shaped member 120 has been left out and the cup-shaped member 123 has been replaced by a horizontal wall part 156 having a central opening 157 therein.
  • the disc 124 has a circular arrangement of sun pictures 125, which may, for example, comprise various corona phenomena.
  • the film unit 139 which substantially corresponds to the film unit of the moon projector, it is possible to provide e.g. solar eclipse, colouring of the sun and sunrise and sunset phenomena.
  • the light from the light source 98 of the projector passes a relatively small opening 158 of an iris diaphragm 159 arranged on a panel member 160 which is ad ⁇ justably mounted by a screw and slot arrangement 161.
  • the armatures of a pair of solenoid actuators 162 are interconnected by a connecting rod member 163 which is pivotally connected to a control arm 164 of the iris diaphragm 159.
  • the iris diaphragm 159 may suddenly be shifted from a first position in which it defines a normal, relatively small diaphragm opening 158, to a second position in which it defines a larger diaphragm opening, and vice versa.
  • Such shifting to a larger diaphragm opening may be used to provide a sudden corona effect by a total eclipse of the sun.
  • planet projectors 43 are constructed on the same general principles as the moon and sun projectors they will not be illustrated in more detail. It should be mentioned, however, that one projector may be used for representing several planets or celestial bodies because the disc 124 shown in figs. 7 and 8 may be used for representing different planets or celestial bodies under various circumstances.
  • the representation of fixed stars 15 and 18 need not be hemi ⁇ spherical, but could be a smaller spherical segment or any other spherical surface part.
  • the apparatus according to the invention could have a single star. body or three or more star bodies which could be projected onto the screen so as to form a desired combined projected picture.
  • the apparatus described above with reference to the drawings could comprise further devices for illustrating part of the celestial sphere, such as a projecting apparatus for providing a "living horizon" as de ⁇ scribed above, or one or more of the projectors for projecting the sun, the moon or planet could be dispensed with, if desired.

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  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
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  • Educational Technology (AREA)
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Abstract

Un appareil destiné à être utilisé pour la démonstration de phénomènes astronomiques comporte un bâti (12) sur lequel est montée une paire de corps d'étoile (13, 14) mutuellement espacés. Chaque corps d'étoile comprend une représentation d'étoiles fixes définissant une partie de surface sphérique et est orientable par rapport au bâti autour d'un point coincidant sensiblement avec le centre de la partie de surface sphérique respective. Une source de lumière est disposée au niveau de la phase concave de la partie de surface sphérique de chaque corps d'étoiles de manière à projeter de la lumière, à travers au moins une partie de ladite représentation, sur un écran (11) au moyen d'un système d'objectif (35). Les représentations des étoiles fixes sur les corps d'étoiles (13 et 14) définissent de préférence en combinaison une représentation de pratiquement la totalité de la sphère céleste, et des moyens sont prévus pour déplacer de manière rotative les corps d'étoiles simultanément et de manière synchrone, une image désirée d'étoiles fixes pouvant être projetée sur l'écran (10). Une pluralité de représentations de corps célestes, y compris les planètes, le soleil et/ou la lune, peuvent être projetées sur l'écran (10) à l'aide de projecteurs séparés (41-43) et déplacés suivant des orbites apparentes par rapport aux étoiles fixes projetées.
PCT/DK1987/000102 1986-08-20 1987-08-19 Procede et appareil de projection pour demontrer des phenomemes astronomiques WO1988001418A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DK3978/86 1986-08-20
DK397886A DK397886D0 (da) 1986-08-20 1986-08-20 Fremgangsmaade og apparat til demonstration af astronomiske faenomener

Publications (1)

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WO1988001418A1 true WO1988001418A1 (fr) 1988-02-25

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Application Number Title Priority Date Filing Date
PCT/DK1987/000102 WO1988001418A1 (fr) 1986-08-20 1987-08-19 Procede et appareil de projection pour demontrer des phenomemes astronomiques

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AU (1) AU7878587A (fr)
DK (1) DK397886D0 (fr)
WO (1) WO1988001418A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2240652A (en) * 1990-02-02 1991-08-07 Burnett Stuart George Clement Instrument for displaying relative positions of astrological or astronomical features

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1608301A (en) * 1925-04-21 1926-11-23 Paul W Charton Device for projecting the different positions of stars
US2178352A (en) * 1937-07-09 1939-10-31 Unglaube Emil Projection apparatus for a small planetarium
US2431847A (en) * 1943-11-08 1947-12-02 Dusen Engineering Company Van Map projection device
DE918537C (de) * 1952-07-03 1954-09-30 Zeiss Carl Fa Einrichtung zur Darstellung der Eigenewegung von Fixsternen in Verbindung mit Projektrionsplanetarien
DE1547523B2 (de) * 1966-05-13 1978-06-22 Spitz Laboratories Inc., Yorklyn, Del. (V.St.A.) Planetarium
US4097134A (en) * 1976-02-24 1978-06-27 Jerie Hans G Projection device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1608301A (en) * 1925-04-21 1926-11-23 Paul W Charton Device for projecting the different positions of stars
US2178352A (en) * 1937-07-09 1939-10-31 Unglaube Emil Projection apparatus for a small planetarium
US2431847A (en) * 1943-11-08 1947-12-02 Dusen Engineering Company Van Map projection device
DE918537C (de) * 1952-07-03 1954-09-30 Zeiss Carl Fa Einrichtung zur Darstellung der Eigenewegung von Fixsternen in Verbindung mit Projektrionsplanetarien
DE1547523B2 (de) * 1966-05-13 1978-06-22 Spitz Laboratories Inc., Yorklyn, Del. (V.St.A.) Planetarium
US4097134A (en) * 1976-02-24 1978-06-27 Jerie Hans G Projection device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2240652A (en) * 1990-02-02 1991-08-07 Burnett Stuart George Clement Instrument for displaying relative positions of astrological or astronomical features

Also Published As

Publication number Publication date
DK397886D0 (da) 1986-08-20
AU7878587A (en) 1988-03-08

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