Patent Document

FIELD 
   Some embodiments disclosed herein relate to optical systems and elements, and in particular to an optical system having a heads-up display (HUD). 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front view of monocular head-up display (HUD) glasses according to one embodiment. 
       FIG. 2  is a front view of binocular HUD glasses according to a second embodiment. 
       FIG. 3  is a schematic view of the optical path through the optical system in the embodiment of  FIG. 1 , unfolded at the planar fold mirror for clarity. 
       FIG. 4  is a top view of the embodiment of  FIG. 2 . 
       FIG. 5  shows a rear view of monocular HUD glasses with optical lenses and mirrors enclosed in mechanical housings according to the embodiment of  FIG. 1 . 
   

   DESCRIPTION 
   For the purpose of promoting an understanding of the principles of the invention, reference will now be made to certain embodiments illustrated in the disclosure, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
   HUDs designed for military use often fail to provide qualities desirable or essential for civilian use. For example, the bulk, weight, and expense associated with many military HUDs prevent those designs from penetrating civilian and especially entertainment markets. 
   The present invention enables HUD systems to be designed that are smaller and lighter than many previous military designs. Various embodiments fit normal-sized glasses, provide enhanced images, produce a field-of-view up to 35° (diagonal), and interface with many portable electronic devices. 
   Generally, a visor HUD according to some embodiments disclosed herein is illustrated in  FIG. 1 , while another is shown in  FIG. 2 . These visor embodiments are in the form of wrap-around glasses, though helmet-based forms, mirror-based forms, and other forms will occur to those skilled in the art in light of the present disclosure. For clarity, the word “visor” will be used to refer to the object that is within the view of the wearer, and off which the generated image(s) reflect(s), though that object might just as well be a lens, mirror, or other (at least partially reflective) object, whether or not the word “visor” would typically be used to describe it. 
   Turning to  FIG. 1 , monocular HUD glasses  100  include frame  110 , stems  120 , and a visor  130  as are customary or desirable. Optical system  140  generates a display image visible to one eye of the wearer on the surface of the visor  130 . In various embodiments this display image includes data and/or images relevant to the user or his or her activities. In some embodiments, the display image relates to a game, e-mail or movie images, while in others it reflects physiological data (such as heart rate, blood pressure, or other data) to the wearer, driving and navigation data, or other information as will occur to those skilled in the art. 
   A second embodiment as shown in  FIG. 2  is binocular HUD glasses that include a pair of optical systems  240  and  245 , each one providing an image to one of the user&#39;s eyes. In addition to the displays discussed above in relation to  FIG. 1 , in various embodiments, these optical systems display data, images, stereoscopic images, and/or  3 -D images as will occur to those skilled in the art. 
     FIG. 3  provides a schematic view of the optical path for one of optical systems  140 ,  240 , or  245  shown in  FIGS. 1 and 2 , which function in a substantially similar manner. For clarity, the fold produced by planar mirror  162  has been removed from the optical path in this view. In this illustrated embodiment, a data source  170  provides information to image generator  152  with which to generate an image for the heads-up display. The image generator  152  can be an OLED or LCD-type display, though other display generators and technologies can be used in this system as will occur to those skilled in the art. 
   The display produced by the image generator  152  passes through lens  154 , a thin, plastic, meniscus-type “corrector” lens, both before and after it is reflected off a curved (e.g., spherical, aspheric, hyperbolic, elliptical, parabolic, or toroid) mirror  156 . In one embodiment, this combination of the spherical mirror  156  and cylindrical lens  154  corrects for the astigmatism and distortion that is caused by the spherical visor reflector  130 . The mirror  156  in this embodiment is preferably a spherical front surface mirror, but can also be a rear surface mirror so as to act as a Mangin mirror. It can be made of any suitable material, even plastic. Lens  158  is matched with lens  160  and lens  154  to place and collimate the image at the pupil  131  of the user&#39;s eye. Lenses  160 ,  158 , and  154  are plastic meniscus lenses in this embodiment, and an intermediate image appears between lens  160  and lens  158 . The various lenses and mirrors of the system can be made of glass, plastic, or any other suitable material. Employing a combination of different plastics for the various lenses and mirrors provides good achromatization of the system, reducing the need for bulkier, heavier glass-type achromats. 
   Finally, the image reflects off the visor  130  of the HUD glasses and to the pupil  131  of the observer. The visor  130  in this embodiment is spherical, though in other embodiments it can be aspheric, parabolic, or toroidal in shape, or still another shape as will occur to those skilled in the art. Further, the visor  130  in this embodiment normally has uniform reflectivity, partial reflectivity, or reflectivity that varies vertically as in the lenses of some conventional sunglasses. The design with a spherical visor is more flexible and less sensitive to minor variations in manufacturing than some other designs. 
   In this embodiment, image generator  152  is preferably OLED type SVGA Microdisplay from eMagin. Other embodiments might use LCD type SVGA Display from Kopin or a similar source. Either of these displays can be used in monochrome or full-color modes. However, the OLED type display is preferred in this exemplary embodiment because of higher brightness and lower power consumption. 
   Lenses  154  and  160  are preferably made of a light plastic material, such as acrylic or polycarbonate, though other lens materials can be used as will occur to those skilled in the art. Likewise, mirror  156  may be spherical, aspheric, parabolic, toroidal, or another shape to form a suitable combination with lens  154  and the rest of the system. In various embodiments, mirror  156  is made of plastic, glass, metal, or other materials as will appear to those skilled in the art. Mirrors  156  and  162  may even be made using a replication process. 
   Lens  158  is preferably a polystyrene or polycarbonate type of plastic. Some of these plastic materials are made/distributed by companies such as General Electric. Other lenses may be used in other embodiments, as will occur to those skilled in the art. 
   Visor  130  is also preferably plastic and in various embodiments is tinted, untinted, treated with variable and/or light-sensitive dynamic tinting, or coated with a thin film reflection coating on one side. This thin film could be applied to a whole side, or to just a patch. The visor  130  is preferably made of polycarbonate plastic or another shatterproof material for improved eye safety, and is attached to the frame  110  using any of a variety of means that will occur to those skilled in the art. 
   The glasses shown in  FIG. 2  include a pair of optical systems  240 ,  245  that each provide a HUD image to one of the user&#39;s eyes. Each optical system includes an image generator  252 , lens  254 , mirror  256 , lens  258 , mirror  262 , and lens  260 , and again reflects the generated HUD image off visor  230 . 
   To review, the embodiment shown in  FIG. 1  is a HUD optical system  140  that uses a lens  154  that is aligned with the optical path, and through which the display image passes twice (once before reflection off a curved mirror  156 , and once after reflection). Further, the disclosure herein shows a HUD display system that uses two non-doublet lenses  158  and  160 , in combination with lens  154 , wherein an intermediate image in the system is generated between lenses  158  and  160 . 
   Turning to  FIG. 5 , this embodiment shows optical assembly  180  attached to frame  110  with attachment features  172 ,  174 , and  176 . In various other embodiments, these features may vary in number and location, and use screws, welded joints, molded post attachments, and other methods of attachment that will occur to those skilled in the art to support optical assembly  180  in a particular relative position to visor  130  of glasses  100 . As shown in  FIG. 5 , the optical assembly  180  is comprised of a plastic housing, all lenses and mirrors, and an image generator  152 . Generator portion  182  of optical assembly  180  in this embodiment includes image generator  152  (which generates its output toward the left in this view), lens  154 , and mirror  156 , as discussed elsewhere herein. Output portion  184  of optical assembly  180  includes lenses  158  and  160 , and folding mirror  162 . The output image from output portion  184  reflects off a visor  130  to a pupil  131  of a user. 
   The data used to create the dynamic display of information, images, and/or video that appears on the displays in various embodiments is dynamically supplied to the first image generator by data source  170  in various ways in different embodiments, as will occur to those skilled in the art. For example, data may be displayed in character form, showing the user symbology, graphics or video images, or any combination thereof. This data may be provided to image generator  152  by external devices such as sensors (for example, GPS or biometric, etc.) or smartphones (for example, images or media). Similarly, still and moving graphics can be produced by video games, portable media players, and the like, and communicated to image generator  152  via wired and/or wireless data transfer techniques (including, for example, Wi-Fi, Bluetooth, Wi-Max, and the like) as will occur to those skilled in the art. 
   While the inventions have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that the preferred embodiment has been shown and described and that changes and modifications that come within the spirit of the invention are desired to be protected.

Technology Category: 3