0)
`
`Europaisches Patentamt
`
`European Patent Office
`
`Office européen des brevets
`
`@) Publication number:
`
`0 045 656
`B1
`
`®
`
`EUROPEAN PATENT SPECIFICATION
`
`® Date of publication of patent specification: 13.11.85
`
`@ int.ci4: G 02 B 25/00, G 02 C 7/14
`
`@) Application number: 81303549.0
`
`@) Dateoffiling: 04.08.81
`
`@®) Vision enhancing system.
`
`
`
`Priority: 05.08.80 US 175412
`
`(@®) Date of publication of application:
`10.02.82 Bulletin 82/06
`
`(@) Publication of the grant of the patent:
`13.11.85 Bulletin 35/46
`
`Designated Contracting States:
`AT BE CH DE FR GBITLILU NL SE
`
`Referencescited:
`CH-A- 579 378
`FR-A-2 172 892
`US-A-2 226 941
`US-A-3 273 456
`US-A-3 893 135
`
`@) Proprietor: RESEARCH TRIANGLEINSTITUTE
`Post Office Box 12194 Research Tringle Park
`Durham North Carolina (US}
`
`@) Inventor: Beadles, Robert L.
`5435 Lake View Drive
`Durham Carolina 27712 (US)
`Inventor: Pekar, Jaroslaw NMI
`Post Office Box 625
`ChapelHilf North Carolina 27514 (US)
`
`Representative: Shaw, Laurence
`George House George Road
`Edgbaston Birmingham B15 1PG (GB)
`
`
`
`EP0045656B1
`
`
`
`Note: Within nine months from the publication of the mention of the grant of the European patent, any person may
`give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shail
`be filed in a written reasoned statement.It shall not be deemed to have been filed until the opposition fee has been
`paid. (Art. 99(1) European patent convention).
`
`Courier Press, Leamington Spa, England.
`
`APPLE 1015
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`APPLE 1015
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`Description
`
`including a support, nose piece and earpieces,
`with eyegldss lenses disposed in the frame
`support. Means are provided for mounting the
`casing on top of the frame support above the
`lenses and between the ear pieces, with the light
`entry and eyepiece disposed sothatby tilting his/
`her eyes upward, the wearer can look through the
`light exit. The casing may be sealed so that dirt,
`moisture, and the like cannot enter the casing and
`affect the lens system, and the lens system itself
`may take a variety of forms depending upon the
`particular use.
`Apparatus of the invention is of low weight,
`about 56 gramsor less, is safe and rugged, yetis
`capable of correcting a low-vision person’s sight
`to 20/20, or closeto it. Magnifications on the order
`of 4x to 8X are readily provided. Utilizing the
`system according to the present invention, a low-
`vision person is not
`immediately identified as
`such, and thus the system according to the
`present invention may be utilized without un-
`desirably increasing the self-consciousnessof the
`wearer.
`:
`.
`A typical low-vision person has one dominant
`eye, and the present invention provides a mon-
`ocular system for aiding the vision of the domin-
`ant eye of the low-vision wearer. However,the in-
`vention also has applicability to other than low-
`vision systems. For instance the apparatus may
`be modified for use in covert surveillance, spec-
`tating at sports and cultural events, etc.
`
`Detailed Description of the Drawings
`Exemplary apparatus according to the present
`invention is illustrated generally at 10 in the
`drawings. The major element of the apparatus
`comprises a casing 12, which preferably is elon-
`gated in dimension L, and may be a rectangular
`parallelepiped. The casing may be made of any
`suitable material,
`preferably
`a_
`lightweight
`material such as aluminum. Means are provided
`defining a light entry 13 into the casing, and
`means are provided defining a light exit 14 (see
`FIGURE3) from the casing disposed on an oppo-
`site portion thereof as the light entry. The casing
`
`The invention relates to a vision enhancing
`system that provides magnification capabilities
`while,
`presenting
`an
`aesthetically
`pleasing
`appearance. Although the invention has other ap-
`plications,
`it
`is primarily to enable low-vision
`persons to read fine print material, to see black-
`board work in educational
`facilities, and,
`in
`general, to provide acceptable distance vision.
`There are a large numberof low-vision persons,
`i.e. those having about 20/200 vision. The visual
`acuity of such individuals is not correctable to
`better than 20/50 with single-lens systems such as
`conventional
`eyeglasses or
`contact
`lenses,
`correction to 20/100 being moretypical. Various
`attempts to enhance the visual acuity of such
`individuals to 20/20 have resulted in the con-
`struction of unsightly and unwieldy opticai struc-
`tures extending forward from the individual’s
`eyes. While such prior attempts were optically
`effective, the forward extension of the optics pro-
`vided an awkward impediment to head move-
`ment and the weight, being well forward of the
`nose support, created an unnatural muscular
`strain.
`it
`is am object of the invention to provide
`improved apparatus for the purpose specified.
`Apparatusof the invention takes advantage of the
`distance between the wearer’s templesto provide
`the major optical path, instead of extending it
`forward from the eyes of the user. By making the
`Brief Description of the Drawings
`optical path parallel to a line between the wear-
`FIGURE 1
`is a perspective view illustrating
`er’'s temples,
`it
`is possible to obtain sufficient
`apparatus according to the present invention in
`magnification while minimizing interference with
`use on a wearer;
`the user’s normal activities and the cosmetic
`FIGURE 2 is a perspective view of apparatus
`drawbacks normally associated with vision-en-
`similar to that of FIGURE 1 shown in use with a
`hancing systems.
`different style of eyeglass frame;
`A sight facilitating apparatus comprising an
`FIGURE 3 is a bottom view of the lens system
`elongate casing containing a lens system and a
`casing of FIGURE 1 with the bottom plate re-
`mounting means for mounting the casing on a
`moved;
`.
`wearer's head so that the direction of elongation
`FIGURE4is a modification of the optical com-
`of the casing extends substantially horizontally
`ponents of the apparatus of FIGURE 3;
`between the wearer’s temples, according to the
`45
`FIGURE5is a view partly in cross-section and
`invention, is characterised in that a single prisma-
`partly in elevation of another embodimentillus-
`tic telescopic system including an objective, an,
`trating a different lens system;
`ocular and inverting and reversing optical means
`FIGURE6 is a side schematic viewillustrating a
`is provided in the housing, that the objective is
`modified manner of interengagement between
`mounted within the casing so that the majority of
`conventionai eyeglass components and a lens
`the focal
`length of the objective extends sub-
`system casing according to the invention.
`stantially parallel to the longitudinal axis of the
`casing, and in that a single light exit is located
`adjacent an eye of the wearer.
`Means are preferably provided for adjusting the
`focus of the lens system from outside the casing,
`and meansare provided for mounting the objec-
`tive within the casing so that the majority of the
`focal
`length of the objective lies within, and
`parallel
`to the direction of elongation of the
`casing. Means are provided for mounting the
`casing on a wearer's head so thatthe direction of
`elongation of the casing extends substantially
`horizontally across the wearer's forehead with the
`light exit at
`the wearer's eye. The mounting
`means preferably comprises an eyeglass frame
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`12 dimension of elongation L preferably is equal
`to or less than the distance between a wearer's
`ears (see FIGURE 1), and the casing 12 has
`shortened second and third dimensions H, W
`compared to the dimension of elongation L.
`‘The apparatus 10 (see FIGURE 3) further com-
`prises a prismatic telescopic lens system,
`in-
`cluding an objective 16 and an ocular 17 mounted
`within the casing 12. The objective 16 and the
`ocular 17 may comprise any suitable lenses. For
`instance,
`the objective 16 may comprise an
`acromatwith a focal length of about 66 mm. The
`ocular 17 preferably includes a field lens 18 and
`an eye lens 19, and may be of symmetrical
`Ramsden type, with a focal length of 12 mm. In-
`verting and reversing optical means (such as a
`plurality of prisms as described below with
`respect to particular embodiments of the lens
`system) are also provided to direct the light
`through the lens system and provide an erect
`image to the eye.
`.
`Means are also provided for adjusting the focus
`of the lens system. Such means mayinclude an
`actuator 22 extending exteriorly of the casing 12
`(see FIGURES 1 and 2) mounted on the “top”
`surface of the casing 12. In the embodimentillus-
`trated in FIGURES 1 through 4, the actuator 22 is
`connected to a shaft 23 which extends through a
`seal (not shown) into the interior of the casing 12,
`and having a peripheral disc 24 mountedfor rota-
`tion therewith. A take-up cable 25 is mounted to
`the circumference of the peripheral disc 24, and
`frictional engagement between the circumference
`of the disc 24 and a stationary friction member 27
`within the casing 12 maintains the shaft 23 in the
`position to which it has been rotated. The cable is
`connected at the end 29 thereof to a block 30
`mountedfor linear slidable movement within the
`casing 12 in dimension L, and guided in that path
`of movement by the walls of the casing 12. A
`spring 31 is connected at one end 32 thereof to
`the block 30, and at the other end 33 thereofto the
`casing 12 to provide spring pressure tending to
`movethe block 30 to the right in FIGURE 3.
`In ail illustrated embodiments, the objective 16
`is mounted by appropriate means within the
`casing 12 so that the majority of the focal length
`extends parailel to the dimension L (direction of
`elongation of the casing 12).
`Means are provided for mounting the casing 12
`on a wearer's head (see FIGURE 1) so that the
`direction of elongation L extends substantially
`horizontally between the wearer's temples, with
`the light exit 14 adjacent the wearer’s eye. Such
`mounting means preferably, especially in low-
`vision applications of the invention,
`takes the
`form of a conventional eyeglass frame including a
`support 40, nosepiece 41, ear pieces 43, 44, and
`eyeglass lenses 45 mounted by the support 40
`(see FIGURES1 and 2 in particular). Any suitable
`eyeglass frame style may be provided; aiter-
`natively, the casing 12 may comprise an integral
`part of the top portion of the eyeglass frame. For
`low-vision systems, the eyeglass frame illustrated
`in FIGURE 1
`is desirable since the height of the
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`lenses 45 is relatively small, allowing the casing
`12 to be. mounted on top of the support 40 and
`readily be utilized by the wearer tilting his eyes
`with respect to his head, an angle a (see FIGURE
`1), much in the same manner that conventional
`bifocals are utilized.
`Preferably the height H of the casing 12 is less
`than the height of the eyeglass lenses 45, and the
`‘width W also is relatively small, preferably small
`enough so that the casing 12 does not extend in
`front of the eyeglass lenses 45 any significant
`extent (see FIGURES 1 and 2).
`Typically, the casing 12, with lens. system dis-
`posed therein, according to the present invention
`would have a weight of about 56 g or less (e.g., 42
`g), and having the relative dimensions with
`respect to the glass frame 40illustrated in FIG-
`URES 1 and 2 would not be uncomfortable to
`wear, and would be aesthetically pleasing, being
`little more obtrusive than conventional eyeglass
`frames. Mounting of the casing 12 to the frame
`support 40 could be accomplished utilizing any
`suitable conventional fastening means, such as
`brackets and screws, adhesives, clips, and the
`like; or (as illustrated in FIGURE 7) the casing 12
`may actually be integral with and form a portion
`of the frame support 40. Mountedas illustrated in
`FIGURE 1, the wearer could tilt his head down-
`wardly at an angle a (a preferably being about
`10°) from a position looking through the eyeglass
`lenses 45, and would then beable to look through
`the light exit 14 of the casing 12. The embodiment
`illustrated in FIGURES 1 through 4 is for a right-
`eye dominant low-vision person; the construction
`of a similar structure for a left-eye dominant low-
`vision person is readily apparent, being a mirror
`image of the structure illustrated in FIGURES 1
`through 4.
`The construction according to the present in-
`vention is simple and rugged, and because of the
`construction thereof the casing 12 may bereadily
`sealed so that dirt, moisture, and the like cannot
`enter the casing and adversely affect the lens
`system. Asillustrated in the drawings, normally
`the focus adjustment actuator 22 extending out-
`wardly from the casing 12 will be adjacent the
`light exit 14 (that is associated with the lens 45
`corresponding to the dominant eye of
`the
`wearer).
`A variety of accommodations may be madein
`the construction of the frame support 40 and the
`eyeglasses 45 if the eyeglasses are. constructed
`with the casing 12 in mind (although the casing 12
`may be readily retrofitted to conventional eye-
`glasses). For instance, as illustrated in FIGURE 7,
`the eyeglass lenses 45’ may be shaped on the
`upper portions 47 thereof to receive the bottom
`and front wall of the casing 12, which is integral
`with frame 40, to help positively locate it, and to
`decrease the effective height H of the casing 12
`above the eyeglasses. Further similar accom-
`modations can be made in the frame 40, with the
`result that a frame with the casing 12 would have
`dimensions corresponding to those of conven-
`tional eyeglasses.
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`A variety of components maybeutilized in the
`lens system along with the objective 16 and
`ocular 17 in order to obtain the desired results.
`Each system will be described in the optical path
`order from light entry to light exit:
`ln the embodimentillustrated in FIGURE 3, the
`first light-redirecting optical element comprises
`an Amici prism 50, then the objective 16, then a
`pentaprism 51, and then the ocular.17. The ocular
`17 is constructed and positioned so that the eye
`lens 19 extends outwardly from the casing 12.
`In the embodimentillustrated in FIGURE 4, a
`flat glass window 52 seals the light entry 13, and
`instead of the Amici prism 50, a mirror 53 is
`provided for redirecting the incident light beam
`so that it exits first optical element 53 in dimen-
`sion L. The objective 16 is next, and then a roof-
`pentaprism 54 is provided, and finally the ocular
`17.
`In the embodimentillustrated in FIGURE 5, the
`ocular is fully recessed, the eye lens 19 being
`flush with the casing 12.
`In the embodiment of
`FIGURE 5, the first optical element comprises
`roof-pentaprism 56; objective 16, the field lens 18
`of the ocular 17, a right-angle prism 58, and the
`eye lens 19 of the ocular. In this embodiment, a
`slide pin 59 is shown schematically for adjusting
`the position of the objective 16 in dimension L, a
`frictional engagement being provided between
`the slide pin 59 where it extends in a sealed
`mannerthrough the upper wail of the casing 12.
`Also in FIGURE5, the casing 12 is shown having
`a modular construction. The modular con-
`struction of the casing allows the readyfitting of
`the apparatus 10 to individuals merely by attach-
`ing modular components together. For instance
`in FIGURE5,the casing 12 is shown as including a
`central modular component 60, and side com-
`ponents 61, 62, with demarcation lines 63, 64,
`respectively, being provided between the center
`60 and side 61 and center 60 and side 62 modules.
`Different side components. 61 may be provided
`with the eye lens 19 positioned with a particular
`spacing with respect to the demarcation line 63 to
`adjust for the particular spacing of the proposed
`wearer's eyes, and similarly the length of the
`component 62 may vary depending upon the
`desired distance between the ear pieces 43, 44.
`The modular components may be connected
`together in any suitable manner, such as with
`snap connections, adhesive,or the like, and seal-
`ing material may be providedat the interfaces 63,
`64, if desired.
`All of the various structures of the apparatus
`may take a wide variety of forms. For instance, the
`meansfor mounting the casing 12 on the wearer’s
`head could comprise a helmet, or comprise clips
`for clipping onto conventional glasses, or could
`comprise a holder for bringing the operative com-
`ponents directly into operative relationship with
`the wearer’s eyes (e.g.,
`for binocular sports
`glasses or the like). Further, the eyeglass lenses
`may be tinted, ground off, or the like to hide the
`casing 12 completely or to any desirable extent.
`Adjustmentof the focus of the lens system may
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`be by a sonar system, or other suitable means,
`and various accessory lenses, mirrors, or the like
`may be associated with the light entrance 13. For
`instance, various sliding or pivotal structures
`such as zoom lenses, mirrors, correcting lenses,
`tinted transparent plates, or the like may be
`mounted on casing 12 for movementinto and out
`of operative relationship with the light entry 13.
`Any number of such structures could be provided
`depending upon the particular use for
`the
`apparatus.
`To assembie apparatus of the invention, the
`various optical components of the lens system
`are mounted in the casing 12 as illustrated in
`FIGURE 3 and the casing bottom is closed. The
`casing 72 is then placed on top of a frame support
`40 of a conventional pair of eyeglasses, for a
`right-eye dominant low-vision person, such as by
`utilizing screws and brackets,
`to provide the
`structure illustrated in FIGURE 1. The ear pieces
`43, 44 are then placed on the wearer’s ears in a
`conventional manner, and the wearer can look
`through the conventional eyeglass lenses 45.
`Whenit is desired to properly view an object in
`the distance, the wearer merely tilts his head
`downwardsor lifts his eyes with respect to his
`head an angle a, and then the wearer may look
`through the ocular 17 at the light exit 14 adjacent
`his dominant right eye. By rotating actuator 22,
`the position of the objective 16 in dimension L is
`adjusted, thereby providing focusing on the ob-
`ject viewed. Light entering through light entry 13
`passes through Amici prism 50, then through
`objective 16, through pentaprism 51, and then
`through ocular 17, providing an upright
`real
`image of the object being viewed.
`It will thus be seen that according the present
`invention a vision enhancing system has been
`provided which makes maximum obtrusiveness
`and minimum discomfort. For low-vision indivi-
`duals,utilizing the present invention is possible to
`correct 20/200 vision to about 20/20 so that the
`individual can read fine print, do blackboard work
`in conventional educational institutions, and the
`like. Yet the apparatus according to the invention
`does not clearly denote the wearer to be a low-
`vision person, and has satisfactory aesthetic
`appeal.
`
`Claims
`
`1. A sight facilitating apparatus comprising an
`elongate casing (12) containing a lens system and
`a mounting means (43, 44) for mounting the
`casing (12) on a wearer's head so that the direc-
`tion of elongation of the casing (12) extends sub-
`stantially horizontaily between the wearer's
`temples characterised in that a single prismatic
`telescopic system including an objective (16), an
`ocular (17) and inverting and reversing optical
`means (50, 51; 52, 53; 56, 58) is provided in the
`housing, that the objective (16) is mounted within
`the casing so that the majority of the focal length
`of the objective (16) extends substantially parallel
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`to the longitudinal axis of the casing, and in that a
`single light exit (14) is located adjacent an eye of
`the wearer.
`2. Apparatus according to Claim 1 characterised
`in that adjusting means (22) accessible from
`outside the casing (12) are present for adjusting
`the focus of the lens system.
`3. Apparatus according to Claim 2 characterised
`in that the adjusting means comprises a rotary
`actuator (22) extending into the casing (12) and
`connected to a block (30) carrying the objective
`(16), rotation of the actuator (22) being arranged
`to move the objective (16) longitudinally of the
`casing (12).
`4. Apparatus according to Claim 1, 2 or 3
`characterised in that the mounting means com-
`prises an eyeglass or spectacle frame (40) and the
`casing (12) is mounted or incorporated in the top
`of the frame (40) with the light entry (13) facing
`forward and the light exit (14) facing rearward
`with respect to the wearer's head.
`5. Apparatus according to Claim 4 characterised
`in that the casing (12) is mounted on the frame
`(40) such that the wearer may see through the
`light exit (14) by tilting his eye upwards through
`an angle of about 10°.
`6. Apparatus according to Claim 4 or 5 charac-
`terised in that the width of the casing (12)
`is
`dimensioned such that the casing (12) does not
`project forwardly a significant distance from the
`eyeglass frame.
`7. Apparatus according to any preceding Claim
`characterised in that the length (L) of the casing
`(12) is substantially equal to the distance between
`the wearer’s temples, and in that the light entry
`(13) and the light exit (14) are spaced apart by a
`distance exceeding the distance between the
`pupils of the wearer’s eyes.
`8. Apparatus according to any preceding Claim
`characterised in that the lens system includes
`mounted in optical path order from the light entry
`(13) to the light exit (14), an Amici prism (50); and
`objective (16); a pentaprism (51); and an ocular
`(17).
`
`Patentanspriiche
`
`1. Sehhilfevorrichtung, bestehend aus einem
`langlichen, ein Linsensystem enthaltenden Ge-
`hause (12) und Halterungen (43, 44) zum Anbrin-
`gen des Gehduses (12} am Kopf eines Tragers,
`derart dass die Langsrichtung des Gehauses(12)
`im wesentlichen waagerecht zwischen den Schla-
`fen des Tragers verlauft, dadurch gekennzeichnet,
`dass ein einziges prismatisches Teleskopsystem
`mit einem Objektiv (16), einem Okular (17) sowie
`umkehrenden und aufrichtenden optischen Ein-
`richtungen (50, 51; 52, 53; 56, 58) im Gehause vor-
`gesehen ist, dass das Objektiv (16) innerhalb des
`Gehausesso angeordnetist, dass der Hauptanteil
`der Brennweite des Objektivs (16)
`im wesent-
`lichen parallel zur Langsachse des Gehdusesver-
`lauft und dass ein einziger Lichtaustritt (14) vor
`einem Auge des Tragersliegt.
`2. Vorrichtung nach Anspruch 1, dadurch ge-
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`kennzeichnet, dass von ausserhalb des Gehauses
`(12) zugangliche Einsteilmittel (22) zur Scharfein-
`stellung des Linsensystems vorhandensind.
`3. Vorrichtung nach Anspruch, 2 dadurch ge-
`kennzeichnet, dass die Einstellmittel ein dreh-
`bares Betatigungsorgan (22) umfassen, das sich
`in das Gehduse (12) hinein erstreckt und mit
`einem das Objektiv (16) tragenden Block (30) ver-
`bunden ist, wobei eine Drehung des Betatigungs-
`organs (22) dazu dient, das Objektiv (16) entlang
`dem Gehduse (12) zu bewegen.
`4. Vorrichtung nach Anspruch 1, 2 oder 3,
`dadurch gekennzeichnet, dass die Halterungen
`aus einem AugenglasoderBrillenrahmen (40) be-
`stehen und das Gehduse (12) auf der Oberseite
`des Rahmens (40) angebracht oder darin ein-
`gebautist, wobei der Lichteintritt (13) gegeniiber
`dem Kopf des Tragers nach vorne und der Licht-
`austritt (14) nach hinten weist.
`5. Vorrichtung nach Anspruch 4, dadurch ge-
`kennzeichnet, dass das Gehduse (12) auf dem
`Rahmen (40) so gehaltert ist, dass der Trager
`durch den Lichtausitritt (14) hindurchsehen kann,
`wenn er das Auge um einem Winkel von etwa 10°
`nach oben richtet.
`6. Vorrichtung nach Anspruch 4 oder 5, dadurch
`gekennzeichnet, dass das Gehause (12) solche
`Breitenabmessungen aufweist, dass es nicht
`wesentlich Uber den Augenglasrahmen nach vorn
`vorsteht.
`7. Vorrichtung nach einem der vorhergehenden
`Anspriche, dadurch gekennzeichnet, dass die
`Lange (L) des Gehaduses (12)
`im wesentlichen
`gleich dem Abstand zwischen den Schlafen des
`Tragers ist und dass der Lichteintritt (13) und der
`Lichtaustritt (14) um einen Abstand auseinander-
`liegen, der grdésser ist als der Abstand zwischen
`den Pupillen der Augen des Tragers.
`8. Vorrichtung nach einem der vorhergehenden
`Anspritche, dadurch gekennzeichnet, dass das
`Linsensystem ein Amici-Prisma (50), ein Objektiv
`(16), ein Pentaprisma (51) und ein Okular (17) in
`dieser Reihenfolge im Strahlengang vom Licht-
`eintritt (13) zum Lichtaustritt (14) angeordnet ent-
`halt.
`
`Revendications
`
`1. Appareil facilitant la vision comprenant un
`long boitier (12) contenant un systéme de lentilles
`et un dispositif de montage (43, 44) pour monter
`le boitier (12) sur la téte d’un porteur de telle sorte
`que la longueur du boitier (12) s’étende en sub-
`stance horizontalement entre les tempes du por-
`teur, caractérisé en ce qu’un systeme téle-
`scopique prismatique unique comprenant un ob-
`jectif (16), un oculaire (17) et un dispositif optique
`inverseur et redresseur (50, 51; 52, 53; 56, 58) est
`prévu dans le boitier,
`l’objectif (16) est monté
`dans Ie boitier de telle sorte que la majeure partie
`de la distance focale de l’objectif (16) s’étende en
`substance paraliélement a l’axe longitudinal du
`boitier et une seule sortie de lumiére (14) est
`placée prés d’un oeil du porteur.
`2. Appareil suivant la revendication 1, caracté-
`
`5
`
`

`

`3
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`O 045 656
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`10
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`tisé en ce qu'un dispositif de réglage (22) acces-
`sible de I’extérieur du boitier (12) est présent pour
`regler la mise au point du systéme delentilles.
`3. Appareil suivant la revendication 2, caracté-
`risé en ce que le dispositif de réglage comprend
`un organe d’actionnement tournant (22) qui s‘é-
`tend dansle boitier (12) et qui est relié a un bloc
`(30) portant l’objectif (16), la rotation de l’organe
`d’actionnement(22) ayant pour effet de déplacer
`’objectif (16) dans le sens longitudinal du boitier
`(12).
`4. Appareil suivant les revendications 1, 2 ou 3,
`caractérisé en ce que le dispositif de montage
`comprend une monture de lunettes (40) et
`le
`boitier (12) est monté sur la monture (40) ou est
`incorporé a ja partie supérieure de celle-ci, |’en-
`trée de lumiére (13) étant orientée vers I’avant et
`la sortie de lumiére (14) vers l'arriére par rapport a
`la téte du porteur.
`5. Appareil suivant la revendication 4, caracté-
`risé en ce que le boitier (12) est monté sur la mon-
`ture (40) de telle sorte que le porteur puisse voir
`
`par la sortie de lumiére (14} en inclinant son oeil
`vers le haut-d’un angle d’environ 10°.
`6. Appareil suivant la revendication 4 ou 5,
`caractérisé en ce que la largeur du boitier (12) est
`telle que ce boitier (12) ne fasse pas saillie vers
`avant d’une distance significative 4 partir de la
`monture de lunettes.
`7. Appareil suivant l'une quelconque des reven-
`dications précédentes, caractérisé en ce que la
`longueur (L) du boitier (12) est en substance égale
`a la distance entre les tempes du porteur et
`entrée de lumiére (13) ainsi que la sortie de
`lumiére (14) sont espacéesl'une de l’autre d'une
`distance supérieure a la distance séparant
`les
`pupilles des yeux du porteur.
`8. Appareil suivant I‘une quelconque des reven-
`dications précédentes, caractérisé en ce que le
`systéme de lentilles comprend, montés dans I’or-
`dre dans fe trajet optique de l’entrée de lumiére
`(13) vers la sortie de lumiére (14), un prisme Amici
`(50), un objectif (16), un prisme pentagonal (51) et
`un oculaire (17).
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`56
`
`60
`
`65
`
`6
`
`

`

`0 045 656
`
`APAge
`
`7
`
`
`

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