Apple is working on a sleep tracking feature called 'Time in Bed tracking' for its new range of Apple Watch wearables.

The new feature will give users the option to wear the Apple Watch in their sleep and if they do, data such as heart rate, motion, and noise, will be used to monitor the sleep quality, news portal 9TO5MAC reported on Monday.

Sleep tracking has been available via a variety of third-party apps but Apple has never provided its own sleep tracking feature.

The Cupertino-based company is expected to launch the new feature as early as next week when the company is expected to announce new iPhones along with Apple Watch Series 5.

Apple Watch Series 5 model is expected to use OLED screens supplied by Japan Display, according to analyst Ming-Chi Kuo.

According to Kuo, Japan Display would gradually increase its proportion of OLED display orders for the Apple Watch, starting with 15-20 per cent of orders in 2019 and reaching 70-80 per cent in 2021.

He believes that Apple would also gradually increase the proportion of LG's supply of OLED displays for iPhones and tap Chinese manufacturer BOE as an additional supplier, in a bid to diversify its supply chain.

Recently, Brazilian site iHelp BR spotted graphics hidden in the beta code of watchOS 6 that points to ceramic and titanium casings quite possibly for the Apple Watch 5, alongside stainless steel for the Apple Watch 4.