Constant-force head mounted display restraint system

Technology is provided for restraint systems for use with head mounted displays and head mounted displays incorporating the same. The head mounted display includes a display unit including a display housing and one or more display devices. A retention assembly attaches to the display unit to support the unit on a user's head. The retention assembly includes at least one tensioner mechanism including a housing having an anchor portion coupled to the display housing and a slider positioned in the housing. A strap is coupled to the slider and configured to support the head mounted display on the user's head. A tension element having a first end portion coupled to the housing and a second end portion coupled to the slider provides a constant force on the strap to comfortably pull the strap against the user's head in order to retain the head mounted display on the user's head.

TECHNICAL FIELD

This patent application is directed to head mounted displays and, more specifically, to the restraint system of a head mounted display.

BACKGROUND

Traditional head mounted displays include a display unit having a video display and a pair of lenses positioned next to the video display. When a user positions the display unit against their face, a strap assembly retains the display unit in position. Conventional strap assemblies require the user to adjust the straps manually each time the display unit is put on. Accordingly there is a need for improved restraint systems to provide comfortable and convenient retention of a head mounted display.

The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed embodiments. Further, the drawings have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be expanded or reduced to help improve the understanding of the embodiments. Moreover, while the disclosed technology is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the embodiments described. On the contrary, the embodiments are intended to cover all modifications, equivalents, and alternatives falling within the scope of the embodiments as defined by the appended claims.

DETAILED DESCRIPTION

Overview

Restraint systems for use with head mounted displays or other head mounted articles are disclosed. In an embodiment, a head mounted display includes a display unit including a display housing and one or more display devices. A retention assembly attaches to the display unit to support the unit on a user's head. The retention assembly includes at least one tensioner mechanism including a housing having an anchor portion coupled to the display housing and a slider positioned in the housing. A strap is coupled to the slider and configured to support the head mounted display on the user's head. A tension element having a first end portion coupled to the housing and a second end portion coupled to the slider provides a constant force on the strap to comfortably pull the strap against the user's head in order to retain the head mounted display on the user's head.

General Description

Various examples of the devices introduced above will now be described in further detail. The following description provides specific details for a thorough understanding and enabling description of these examples. One skilled in the relevant art will understand, however, that the techniques discussed herein may be practiced without many of these details. Likewise, one skilled in the relevant art will also understand that the technology can include many other features not described in detail herein. Additionally, some well-known structures or functions may not be shown or described in detail below so as to avoid unnecessarily obscuring the relevant description.

FIG. 1illustrates a head mounted display100according to a representative embodiment. The head mounted display100includes a display unit102and a retention assembly104configured to support the head mounted display100on a user's head. The display unit102includes a housing106with one or more display devices (not shown) positioned within the housing106.

The retention assembly104includes at least one tensioner mechanism108coupled to the housing106. In some embodiments, the retention assembly104includes a pair of tensioner mechanisms108coupled to opposite sides of the housing106. A strap assembly110is coupled to the tensioner mechanisms108and is configured to support the display unit102on the user's head. The strap assembly110includes a pair of lateral strap portions112, an occipital lobe cradle116interconnecting the pair of lateral strap portions112, and a top strap114extending between the display unit102and the occipital lobe cradle116. In some embodiments, the tensioner mechanism108provides a substantially constant force on the strap110to comfortably pull the strap110against the user's head in order to retain the display unit102on the user's head.

As shown inFIGS. 2 and 3, the tension mechanism108includes a housing120including a first panel122and a second panel124joined together by a plurality of suitable fasteners, such as screws130. The first panel122includes an anchor portion126coupled to the display housing106(FIG. 1). In some embodiments, the anchor portion126snaps into the display housing106and is rotatable with respect to the display housing106. The first panel122and the second panel124form an interior slideway127. Slider128is positioned in the slideway127for reciprocating axial movement therein. In some embodiments, the slider128is coupled to the lateral strap portions112with suitable fasteners, such as bolts134and nuts132.

With reference toFIGS. 4A and 4B, the slider128can be moved axially back and forth in slideway127against the force of a tension element140. The tension element140has a first end portion142coupled to the housing120and a second end portion144coupled to the slider128. The first end portion142is contained in a spring cavity148of the second panel124. The second end portion144is coupled to the slider with a screw146or other connection element. In the illustrated embodiment, the tension element140is a constant-force spring constructed as a rolled ribbon of spring steel or other metal, such that the spring is in a retracted position when it is substantially fully rolled up, as shown inFIG. 4A. As it is unrolled away from the retracted position, the restoring force FRis generated primarily from the curved portion of the ribbon near the roll. Because the geometry of that region remains nearly constant as the spring unrolls, the resulting force is substantially constant. Thus, the restoring force when the ribbon is rolled up and the slider128is in the retracted position (FIG. 4A) and the restoring force when the ribbon is unrolled and the slider128is in the extended position (FIG. 4B) are substantially the same.

The restoring force FRconstantly pulls axially on the slider128toward the retracted position, thereby urging the strap110and/or the display housing106(FIG. 1) against the user's head and automatically adjusting the straps to fit the user's head without manual adjustment. In addition, the constant force provided by the tension element140provides a constant comfortable fit no matter how big the user's head or how far the strap is pulled toward the extended position.

As shown inFIG. 5, the tension element140is rolled or wound around a spool150. The spool150includes spaced apart flanges152adapted to position the tension element140on the spool. The spool is positioned on an axle156that is secured in the spring cavity148(FIG. 4B). The axle156extends through a spool bore154formed through the spool150. Accordingly, the spool150can rotate about the axle156. The axle156is secured in the spring cavity148with screws160that thread into threaded bores158.

Although the embodiments described herein are directed to tension elements in the form of a rolled ribbon of spring steel, other substantially constant force tension elements may be used. For example and without limitation, in various embodiments, the tension element can comprise a clock-type spring, an elastic element, and/or a coil extension spring. The disclosed restraint systems for use with head mounted displays can also be used on other head mounted articles, such as for example and without limitation, welding masks, scuba masks, head lamps, helmets, and face shields.

Remarks

The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. It will be appreciated that the same thing can be said in more than one way. Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, and any special significance is not to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for some terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification, including examples of any term discussed herein, is illustrative only and is not intended to further limit the scope and meaning of the disclosure or of any exemplified term. Likewise, the disclosure is not limited to various embodiments given in this specification. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions, will control.