Description:

The system stated here is comprised of a Head Mounted display and a host device that is connected using a wireless connection. The information sent through this connection can be of several sensor modules fitted in the HMD or data sent to the HMD from the host device to perform a task.
The model diagram of HMD has been depicted in FIG.1.
A. Proposed Model
The different parts that make the HMD and the system work as desired are described in this section:
i) Head Mounted Display: It is a mixed reality headset that does the following tasks:
a) The sensor data and user inputs it captures is sent to the host device for different purposes.
b) It displays any image data it receives from the host device using projectors.
c) It plays any sound data received from the host device using its bone conduction transducer.
d) Tactile data is also received by the HMD for user experience.ii) Host Device: The host device is any device with enough computing resources to run X-server on its operating system and has the capability of processing 3D graphics.
The components present in the Head Mounted Display along with their specifications are as follows:
i) The input components present in the HMD are:
a) Structured Light Scanner cameras: Four 1.3MP SLS cameras with 1080p resolution b) Accelerometer: Sensitivity of 100 mV/g and the dynamic range is +/-50 g, peak. 30-900,000 CPM (+/3dB)c) Gyro sensor: ±300°/s range
d) Microphone
e) Light Dependent Resistor
f) Buttons and scroll wheel: 2 buttons and 1 scroll wheel which contains 2 more buttons.
ii) The output components fitted in the HMD are:
a) Projector: 1920x1080. Quantity- 2pieces.
b) Bone conduction transducers (speakers)
c) Haptic moduleiii) Few other components that are also required are as follows:
a) Wi-Fi module: IEEE 802.11ac
b) Battery: 5000mAh capacity
c) Voltage regulator
d) Processor: ARM processore) USB Type C
f) RAM: 4GB
B. Methodology
The working mechanism of the proposed model can be described as follows:
Stage 1: (initialization of HMD)
1. The headset tries to connect with the host device and it keeps on trying in a loop until the connection is established.
2. Then the headset checks if mixed reality window manager is running on the host device. If it is running the headset initializes the modules that were inactive till now.
Stage 2: (initialization of host device)
1. The window manager is started in the host device and web socket is created to connect with HMD.
2. If connection is not established then window manager runs in a simple 2D mode. But if connection is established the window manager runs in 3D mixed reality mode.Stage 3: (HMD main loop)
1. The HMD collects data from all the input devices (microphone, buttons and scroll wheel) and some of the sensor modules (SLS cameras, LDR, accelerometer and gyro sensor). This data is serialized and sent to the host device using the connection it established earlier.
2. The HMD also receives data from the host device in the form of an input stream and depending on the type of data received the HMD performs a task. If it is image data it is displayed using the projectors, if it is sound then the bone conduction transducers are used and the haptic module in case of tactile output.
Stage 4: (Host device main loop)
1. The mixed reality window manager receives data of different modules from the HMD using the socket connection established earlier.2. The accelerometer and gyro sensor data are used by the window manager to move the virtual camera according to user movement. The LDR data is used to set the brightness of the projector. Structured Light Scanner camera data is used to recreate the real-world environment in the virtual world. The microphone data and the button input data is forwarded to the operating system.
Stage 5: (HMD shutdown procedure)
1. When the user long presses the power button, the shutdown routine of the HMD starts. The socket connection with the host device is ended. All the processes in the HMD end and all the modules are stopped.
Stage 6: (Host device shutdown procedure)
1. When the user shutdowns the host device, the socket connection ends and window manager process also ends. The rest of the shutdown procedure is managed by the operating system of the host device.

Claims:

1. The HMD is very compact and lightweight.
2. The design looks similar to sunglasses, so that the user feels comfortable to wear it anywhere they want.
3. It is cost effective and increases productivity of the user by removing the need of multiple hardware screens at the same time.
4. The host can be any device that is capable to run X Server and has enough processing capability and main memory.