# Patent

## Title
Heads-up display with an achromatic lens for use in underwater applications

## Abstract

A heads-up display comprises a housing. A display panel is disposed within the housing. An objective lens is disposed within the housing. An achromatic lens is disposed within the housing between the display panel and the objective lens.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heads-up display and, in particular, to a heads-up display with an achromatic lens for use in underwater applications.
2. Description of the Related Art
It is known to mount a heads-up display on headgear. For example, U.S. Pat. No. 6,868,360 which issued on Mar. 15, 2005 to Olstad et al., discloses a heads-up display with a waterproof housing having a mounting mechanism which engages a part of a headgear worn by a user to position the heads-up display in a portion of a forward field of view of the user. A magnetic field sensor module is disposed within the housing and provides magnetic field data signals. An optical element having a wide field of view transmits data images representative of the magnetic field data signals to eyes of the user. Compass data may thereby be viewed by the user in low visibility conditions.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved heads-up display.
There is accordingly provided a heads-up display comprising a housing. A display panel is disposed within the housing. An objective lens is disposed within the housing. An achromatic lens is disposed within the housing between the display panel and the objective lens. Information on the display panel is visible by a user looking through the objective lens and the achromatic lens. The heads-up display is coupled to a rebreather by a mounting arm. The mounting arm may be an articulated mounting arm.
The improved heads-up display disclosed herein may be used to effectively display information with limited chromatic and spherical aberration.



BRIEF DESCRIPTIONS OF DRAWINGS
The invention will be more readily understood from the following description of the embodiments thereof given, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a heads-up display mounted on a rebreather and a head of a user;
FIG. 2 is a cross-section view of the heads-up display of FIG. 1 and the head of the diver; and
FIG. 3 is an elevation view of a display panel of the heads-up display of FIG. 1.



DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
Referring to the drawings and first to FIG. 1, a rebreather 10 is shown in fragment. The rebreather 10 is a conventional rebreather commonly used by divers and is accordingly not described in detail herein. There is an improved heads-up display 12 coupled to the rebreather 10 by a mounting arm 14. The mounting arm 14 is an articulated arm in this example which allows a user 16 to adjust a position of the heads-up display 12 in order to place the heads-up display 12 in a line of sight of the user 16 through goggles 17. In this example, the mounting arm 14 is press-fitted to the heads-up display 12.
The heads-up display 12 is best shown in FIG. 2 and is substantially cylindrical and elongate in this example but may be any shape. The heads-up display 12 comprises a housing 18 having a proximal end 20 and a distal end 22 relative to the rebreather 10. The proximal end 20 of the housing 18 is connected to the mounting arm 14 and the distal end 22 of the housing 18 faces the user 16. There is a display panel 24 disposed within the housing 18. The display panel 24, shown in greater detail in FIG. 3, is a conventional display panel used in heads-up displays and is accordingly not described in detail herein. In this example, the display panel 24 is an LED display panel but may be any type of display panel. Referring back to FIG. 2, in this example, the display panel 24 is connected to a dive computer (not shown) by a cable 26 which allows communication between the heads-up display 12 and the dive computer. However, in other examples, the heads-up display 12 may be in wireless communication with the dive computer.
There is an objective lens 28 disposed within the housing 18 towards the distal end 22 thereof and an achromatic lens 30 disposed within the housing 18 between the display panel 24 and the objective lens 28. Information on the display panel 24 is visible by the user 16 looking through the objective lens 28 and the achromatic lens 30.
It will be understood by a person skilled in the art that many of the details provided above are by way of example only, and are not intended to limit the scope of the invention which is to be determined with reference to the following claims.

## Claims

1. A heads-up display comprising:
a housing;
a display panel disposed within the housing;
an objective lens disposed within the housing; and
an achromatic lens disposed within the housing between the display panel and the objective lens;
wherein the heads-up display is coupled to a rebreather by a mounting arm.

2. The heads-up display as claimed in claim 1 wherein information on the display panel is visible by a user looking through the objective lens and the achromatic lens.

3. The heads-up display as claimed in claim 1 wherein the mounting arm is an articulated mounting arm.

4. A heads-up display comprising:
a housing;
a display panel disposed within the housing;
an objective lens disposed within the housing; and
an achromatic lens disposed within the housing between the display panel and the objective lens;
wherein the heads-up display is coupled to a rebreather.