WO2008049130A2

WO2008049130A2 - Illumination port for an optical device

Info

Publication number: WO2008049130A2
Application number: PCT/US2007/082116
Authority: WO
Inventors: Sergey Yury Zaderey
Original assignee: Leupold & Stevens, Inc.
Priority date: 2006-10-21
Filing date: 2007-10-22
Publication date: 2008-04-24
Also published as: WO2008049130A3

Abstract

Illumination in an optical device (10) is provided via a light conductor (44) combined with a light source (70) or light collecting device detachably mounted to the optical device (10). A seal (94) between the light conductor (44) and the optical device housing (14) prevents moisture and other contaminants from entering the housing (14). The light source (70) or light collecting device may be removable and interchangeable to allow various types of illumination sources to be selected, installed, and replaced without affecting the integrity of the optical device (10).

Description

ILLUMINATION PORT FOR AN OPTICAL DEVICE

Technical FieSd

[0001] The field of the present disclosure relates to riflescopes and other optical devices, and to devices and methods for illuminating a reticle or other visual indicia viewable in the field of vie.w of the optical device.

Background

[0002] Optical devices such as riflescopes, binoculars, and spotting scopes often include visual indicia, for example, aiming reticles, other markings, or data, singularly or combined, in the field of view. In some riflescopes, the aiming reticle is illuminated to improve visibility of the crosshairs and other aiming marks in low light conditions, illumination systems add weight, bulk and complexity to the optical device and often include fragile electronic components that are more prone to failure than other components of the optical device. Known illumination systems typically introduce an additional potential pathway for moisture to invade the housing of the optical device, which can compromise the optical performance of the device and the illumination system. Known illumination systems also typically utilize light sources that cannot be easily changed. For example, U.S. Patent Nos. 4,977,677 of Troescher, Jr. and 6,802,131 of Scholz et al. do not mention or discuss maintaining a sealed optical environment and utilize light sources either internal to an optical device or requiring a linkage to an optical device.

[0003Ϊ The present inventor has recognized that illumination source technologies are rapidly improving, resulting in a relatively short obsolescence horizon for older technologies. [0004] The present inventor has therefore identified a need for an improved means of illuminating reticles, aiming marks, data displays, and other indicia in the field of view of a riflescope, binocular, spotting scope, or other optical device.

Summary

[0005] \n one embodiment, a housing of an optical device includes an illumination port comprised of an opening in the housing within which a light-transmitting medium is positioned. The light-transmitting medium allows illumination from a light source outside of the housing to be transmitted through the housing for illuminating a reticle, aiming mark, indicia, or data display located within the housing. In preferred embodiments, a hermetic seal is provided between the light-transmitting medium and the housing of the optical device to maintain a clean, dry environment within the optical device, to thereby prevent fogging or other degradation of the optics. A multitude of light sources may be utilized by simply illuminating the opening (as by shining a flashlight into the opening) or by affixing a light source to the optical device to orient the light source towards the opening.

[0006] In another embodiment, an illuminatable display for an optical device includes an aperture through an optical device housing proximate to a display body contained within the housing. The display body bears visual indicia such as etchings, deposited material, electronically generated images, or otherwise. A light conductor is retained within the aperture and extends adjacent to a peripheral edge of the display body. The light conductor is substantially shorter than the distance around the display body. The light conductor has an input surface for receiving illumination from a light source and an output surface for emitting illumination into the display body. A seal between the light conductor and the housing prevents moisture and other contaminants from entering the housing through the aperture. Illumination from a tight source external to the housing travels through the light conductor and into the display body to illuminate the visual indicia.

[0007] In another embodiment, an optical device includes a housing supporting an optical system having a display. An opening extends through the housing adjacent the display, and a light conductor is retained within the opening and extends adjacent to a peripheral edge of the display body. The light conductor has an input surface for receiving illumination from a light source and an output surface for emitting illumination into the display body, the output surface being substantially defined by the cross- sectional area of the light conductor. A seal between the light conductor and the housing prevents moisture and other contaminants from entering the housing through the aperture, and illumination from a light source external to the housing travels through the light conductor and into the display body to illuminate the visual indicia. A iight source is detachably mounted to the housing.

[0008] A system for illumination in an optica! device comprises the light-transmitting illumination port, combined with a light source or light collecting device mounted to the housing of the optical device. The light source or iight collecting device may be removable and interchangeable to allow various types of illumination sources to be selected, installed, and replaced without affecting the integrity of the optical device. [0009] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

Brief Description of the Drawings

[0010] FiG. 1 is an axiai cross section view of an optica! device showing detail of an aiming reticle and an illumination port;

[0011] FIG. 2 is an axial cross section view of the optical device of FIG. 1 with an illumination source mounted to the optical device; and

[0012] FIGS. 3 and 4 are longitudinal cross section views showing detail of two alternative embodiments of the illumination port of FIG. 1.

[0013] FIG. 5 is a cross section view of a portion of an exemplary optical device including an illumination port and illumination source.

Detailed Description of Prefer[ed_Embodiments

[0014] FIGS. 1 and 2 are axial cross section views of an optical device 10 such as a riffescope, spotting scope, binocular, rangefinder aiming device, telescope, or the like. Visual indicia, such as the cross-hairs illustrated in FIGS. 1 and 2 may be difficult to perceive in low light conditions or when there is insufficient contrast between the visual indicia and the objects being viewed. Persons using an optical device 10 may desire to illuminate the visual indicia to enhance perceiving the visual indicia. [0015] With reference to FIG. 5, the optical device 10 includes a housing 14 supporting an optical system therein. The optical system may include, for example, an objective lens (not shown), an eyepiece lens 11 , and an erector system 12 interposed between the objective and eyepiece lenses. A display body 24, for example, a reticle 22, may also be included. However, the particular elements of the optical system may differ from one embodiment to the next. The optical system defines an optical axis 50 (FiG. 3).

[0016] FIGS. 1 and 2 illustrate a display 20 preferably comprising a visual indicia, such as reticle 22, formed on or in a display body 24 of optical materia!, such as a glass disk, a plastic disk, or other optical grade material. Display 20 is preferably supported in or mounted to a display housing 26 made of a ring of a durable material. Display housing 26 is secured within housing 14 by a retainer ring 28 (FIGS. 3 and 4) threaded inside of housing 14 to capture display housing 26 against an opposing ledge 32 formed in housing 14. Reticle 22 includes a pattern of aiming marks 38 formed on or in display body 24 which are visible in the field of view of the optical device and, in some embodiments, may be used to aim a weapon (not shown) to which the optical device may be attached. In the embodiment depicted in FIGS. 1 and 2, the aiming marks 38 comprise horizontal and vertical aiming lines or "crosshairs" etched or deposited on one or both facing surfaces of the display body 24. In other embodiments (not shown), display 20 may include other types of static marks, an active electronic display device such as a transparent liquid crystal display (LCD) or organic light emitting diode (OLED) display, or other visual indicia formed in or on a body of optical material. [0017] According to one embodiment, an illumination system 40 includes an illumination port 42 comprised of a light-transmitting medium 44 positioned within an opening 46 in housing 14. Opening 46 extends through housing 14 at a location adjacent an outer peripheral edge surface 48 of the display body 24 of display 20. The opening 46 extends through the housing 14 transversely of the optical axis 50 of the optica! device 10. In other embodiments, the opening 46 is not transverse to the optical axis 50, but may be off-set at an angle desired for illuminating visua! indicia on the display body 24.

[0018] The light-transmitting medium 44 forms a conductor for transporting light from outside housing 14 to display 20, and includes an input surface 54 facing outwardly of housing 14. In the illustrated embodiments, input surface 54 is positioned flush or recessed relative to an outer major surface 58 of housing 14. The input surface 54 is oriented to receive illumination from a removable external light source 70 (FIG. 2), such as a light emitting diode (LED) 74, which may be positioned adjacent to or pressed against the input surface 54. Light source 70 may be secured to housing 14 by a mounting ring 80 to which light source 70 is detachably mounted. The mounting ring 80 may be split and hinged by hinge 82 at one side and removably secured around housing 14 opposite hinge 82 by a screw 86, which facilitates secure installation and easy removal of light source 70.

[0019] In other embodiments (not shown), light source 70 may be detachabiy secured to housing 14 by other mounting devices. Light source 70 may also comprise other types of illumination devices, in other embodiments (not shown), light source 70 may be detachably secured to illumination port 42, for example via threads. In other embodiments (not shown), the light-transmitting medium 44 may project beyond an outer major surface 58 of housing 14 and a light source 70 may be detachably secured to the light-transmitting medium.

[0020] In other embodiments (not shown) light source 70 may not be attached to the optical device 10 at al!, but may be held in proximity to the input surface 54 or oriented towards the input surface 54. Thus, the illuminatabie display body 24 does not require a light source 70 to be attached to the optical device 10 or to be connected to the light transmitting medium 44 in order to illuminate visual indicia. Light sources 70 may be quickly and easily exchanged, and practically any light source will work to illuminate visual indicia on or in display body 24 as there is no need for a particular configuration for a light source 70 to operate in conjunction with the illumination port. [0021] In the illustrated embodiments, light-transmitting medium 44 is retained within opening 46 by a lock ring 90, threaded into a threaded counter bore in housing 14. An o-ring, gasket or other seal 94, preferably made of an elastomeric material, is positioned in a second counter bore beneath the lock ring 90, between housing 14 and light- transmitting medium 44 and between housing 14 and lock ring 90. Sea! 94 is designed to prevent moisture and other contaminants that could degrade the optical system from entering housing 14 through opening 46. An airtight and water-tight seal is created by threading lock ring 90 into the threaded counter bore and compressing seal 94 between lock ring 90 and housing 14, as depicted in FIGS. 1 and 2, thereby deforming the seal 94. In alternative embodiments, the light-transmitting medium 44 may fill or plug the opening in the housing and be tightly sealed directly to the housing 14. For example, the light-transmitting medium may be itself made of a resilient material that conforms to and seals against the sides of the opening 46. Alternatively, the light-transmitting medium 44 may be secured and sealed within the opening 46 by an epoxy or instant adhesive, such as cyanoacrylate (super glue).

[0022] With reference to FIGS. 3 and 4, light-transmitting medium 44 is desirably shaped to channel light from external light source 70 through the input surface 54 to the output surface 100 using the principle of total internal reflection (TIR). fn other embodiments (not shown), light-transmitting medium 44 may have a reflective coating or material around its periphery to assist channeling light from an external light source 70 to the output surface 100. A reflective coating or material may cover all of the outer surface of ϋght-transmitting medium 44 except for the input surface 54 and the output surface 100.

[0023] Output surface 100 may be substantially defined by the cross sectional area of light-transmitting medium 44, As illustrated, output surface 100 is smaller than the cross sectional area of light-transmitting medium 44 where iight-transmitting medium 44 passes through opening 46, however output surface 100 may be the same as or larger than the cross sectional area of light-transmitting medium 44 where light-transmitting medium 44 passes through opening 46.

[0024] The relatively small output surface 100, compared to the total surface area of the outer peripheral edge 48 of display body 24, permits illumination system 40 to be compact and does not require large amounts of optical grade materials for the light conductor. In the illustrated embodiments, the light conductor formed by light- transmitting medium 44 is substantially shorter than the distance around display body 24, which provides a short path for light to travel from source 70 to display body 24. [0025] Light-transmitting medium 44 can be index-matched to display body 24, or step-indexed between light source 70 and dispiay body 24, such that the index of refraction of light-transmitting medium 44 is selected to enhance light transmission between light source 70 and display body 24. An output surface 100 of light- transmitting medium 44 opposite input surface 54 preferably includes a light-diffusive topology to cause light exiting from light-transmitting medium 44 to scatter. Exemplary light-diffusive topologies include lightly abrading output surface 100, attaching a diffusing material such as a thin film of milky plastic, and other suitable structures for scattering light. The light-diffusive output surface 100 may physically touch the outer peripheral edge 48 of display body 24, eliminating most of the air gap; and can be further made efficient by applying an index-matched optical gel between output surface 100 and outer peripheral edge 48. By scattering the light conducted through the light- transmitting medium 44, the diffusive output surface 100 provides brighter and more uniform illumination of reticle pattern 38. Diffused light emitted from light-transmitting medium 44 into the display body 24 may also boost the performance of holographic film or Fresnel-type micro grating patterns when they are incorporated into display 20. In certain embodiments, lock ring 90 preferably presses light-transmitting medium 44 against outer peripheral edge 48 of display body 24 to further reduce or eliminate the air gap between light-transmitting medium 44 and display body 24. [0026] The geometry of the light-transmitting medium 44 can be altered to suit different requirements. A "plug type" geometry (illustrated in FlG. 3) may provide a better seal to housing 14 and can be used effectively in a thin-walled housing 14; while a "taper type" geometry (illustrated in FiG. 4) may be more efficient at transmitting a greater percentage of the source light to display 20 via TiR. A tapered geometry (FIG. 4) may need to be implemented in a thick-wailed housing 14 to work effectively, since some degree of length will be required to facilitate TIR geometry (relative to the incident light angle) and produce a proper seal.

[0027] Light that exits from output surface 100 enters display body 24 and is transmitted through body 24 by TIR to reticle pattern 38, which then reflects the light and/or glows (e.g., phosphoreseces) and/or fluoresces in response to absorption of some of the light. The reticle pattern 38 or other visual indicia may be formed on one of the faces of display body 24 by etching into the face of the display body 24. The visual indicia may also be formed by depositing thin films of titanium dioxide material either on the display body 24 or in etched regions of the display body 24. Reticle pattern 38 may also comprise photoluminescent markings, which may be formed by depositing a fluorescent material or phosphorescent material on one of the faces of the body 24, for example. Visual indicia may also be formed internally to display body 24. Alternatively, the reticle pattern 38 may be generated by elements of an eiectronic display which reflect or pass light. For example, reticle pattern 38 or other visual indicia may comprise an LCD or OLED display (not shown) formed on a body of transparent optical material. !n another embodiment, display 20 may be formed on the back of a reflective surface of an image-folding erector system, as described for example in U.S. Patent No. 4,806,007 of Bindon. Thus, the term "display" should be construed broadly to include various types of devices and means suitable for producing a visual display in an optical device. [0028] Various kinds of external light sources 70 can be used to illuminate reticle pattern 38 or other indicia or visual display elements. For example, light source 70 may comprise LEDs, incandescent lamps, radioluminescent sources (such as tritium), chemoluminescent sources, and photoluminescent sources, for example. Light source 70 may also comprise a light-collecting member (not shown) which collects, conducts, and concentrates ambient light. An example of such a light collecting device is described in Bindon US 4,806,007.

[0029] As indicated above, light source 70 can be mechanically attached to the optical device 10, or removed entirely to eliminate weight, bulk and complexity. Optical device 10 can be sold without light source 70 to avoid the major cost of the illumination system 40 and the inevitability of light source obsolescence (electronics, features, LED technology, tritium degeneration, chemical source effectiveness, fiber optic material efficiency, etc.), while the modular design allows the addition of a light source 70 when needed, illumination system 40 preferably provides the user with the ability to upgrade, exchange or eliminate the light source 70 as desired for the life-cycle of the optical device 10. The illumination port and light conductor of illumination system 40 also allows a user to illuminate the display 20 without attaching a light source to the housing 14. For example, a user can shine a flashlight into the illumination port to iiluminate the reticle pattern 38.

[0030] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims.

Claims

1. An ilSuminatable display for an optical device, the optica! device having a housing supporting an optical system, the iiluminatable display comprising: an aperture through the housing adjacent to a display body contained within the housing, the display body bearing visuai indicia; a light conductor for use with multiple light sources regardless of whether the light source is configured or is not configured for use with the iiluminatable display, the light conductor retained within the aperture and extending adjacent to a peripheral edge of the display body; the light conductor having an input surface for receiving illumination from a light source and an output surface for emitting illumination into the display body; a seal between the light conductor and the housing to prevent moisture and other contaminants from entering the housing through the aperture; and wherein illumination from a light source external to the housing travels through the light conductor and into the display body to illuminate the visual indicia.

2. The iiluminatable display of claim 1 , wherein the light conductor is shaped to enhance total internal reflection.

3. The iiluminatable display of claim 1 , wherein the light conductor further comprises a reflective material or reflective coating covering its outer surface except for the input surface and the output surface.

4. The iiluminatable display of claim 1 , wherein the output surface includes an optical diffusion topology.

5. The iiluminatable display of claim 1 , wherein the light conductor abuts the display body peripheral edge to direct light into the display body.

6. The iliuminatable display of claim 5, wherein the light conductor has an index of refraction matched to an index of refraction of the display body.

7. The iiluminatable display of claim 6, further comprising an index of refraction matched gei between the light conductor and the display body.

8. The iiluminatable display of claim 5, wherein the light conductor has an index of refraction that is step-indexed between an index of refraction of the body and an index of refraction of the light source.

9. The illuminatabie display of claim 1 , wherein the display body includes a reticle disk, and the visual indicia include reflective markings on the reticle disk.

10. The illuminatable display of claim 1 , wherein the light conductor is substantially shorter than the distance around the display body.

11. The illuminatable display of claim 1 , wherein the output surface is substantially defined by the cross-sectional area of the light conductor.

12. The illuminatable display of claim 1 , wherein the visual indicia are electronically generated.

13. The illuminatable display of claim 1 , wherein the visual indicia include photoluminescent markings.

14. The illuminatable display of claim 1 , wherein the display body comprises an electronic display device.

15. The illuminatable display of claim 14, wherein the electronic display device is selected from the group comprising an organic light emitting diode (OLED) device and a liquid crystal display (LCD) device.

16. The iliuminatabie display of claim 1 , further comprising a detachably mounted light source.

17. The iliuminatabie display of claim 16, wherein the light source is detachably mounted to the housing,

18. An illumination system for an optical device, the optical device including a housing supporting an optica! system having an optica! axis and a display, the iilumination system comprising: an opening extending through the housing adjacent the display and transversely of the optical axis; a light-transmitting medium positioned within the opening, the light-transmitting medium including an input surface facing outwardly of the housing and an output surface adjacent the display, the input surface oriented to receive illumination from a removable external light source, the output surface substantially defined by the cross- sectional area of the light-transmitting medium positioned within the opening, the light- transmitting medium shaped to conduct light from the external light source through the opening and to the display; and a seal between the light-transmitting medium and the opening for preventing moisture and contaminants from passing through the opening.

19. An optical device comprising: a housing supporting an optica! system including a display; an opening extending through the housing adjacent the display; a light conductor for use with multiple light sources regardless of whether the light source is configured or is not configured for use with the iliuminatabie display, the light conductor retained within the opening and extending adjacent to a peripheral edge of the display body; the Sight conductor having an input surface for receiving illumination from a light source and an output surface for emitting illumination into the display body; a seal between the light conductor and the housing to prevent moisture and other contaminants from entering the housing through the aperture; and wherein illumination from a light source external to the housing travels through the light conductor and into the display body to illuminate the visual indicia.

20. The optical device of claim 19, further comprising a light source detachably mounted to the housing.