Apple's (NASDAQ:AAPL) highly anticipated iPhone 6 lineup is rumored to consist of two larger phones, a 4.7-inch version and a phablet-like 5.5-inch version. As Apple's largest business segment, accounting for 57% of the tech giant's revenue in its most recent quarter, investors are hoping the new form factor could reinvigorate iPhone sales growth. Investors may get their wish. Apple appears to have considerable confidence in its next-generation smartphone. Here are three reasons why:

1. A hiring spree
Last month, a report from Taiwan's Economic Daily News (via Reuters) said that Apple's largest iPhone manufacturer, Foxconn, is boosting its workforce by 10%, or 100,000 workers, compared to the human resources needed for iPhone 5 and 5s production.

After taking into account the hiring at Apple supplier Pegatron, this hiring spree is so significant that it will play a role in driving greater job creation in the mainland than has been seen in recent memory, Economic Daily said. The Chinese news site said Pegatron is boosting its workforce by 30% for iPhone 6 production.

4.7-inch and 5.5-inch iPhone 6 mockups pictured with the 4-inch iPhone 5s. Source: 9to5Mac, used with permission.

2. 10,000 robots
But Apple and Foxconn's investment in iPhone 6 production goes beyond human resources. Foxconn CEO Terry Gou recently announced that it will soon be putting 10,000 robots to work in its factories, according to IT Home (via MacRumors). Apple, of course, will be the first to use the robots, IT Home says.

These robots, dubbed "Foxbots," can each assemble about 30,000 devices per year, Gou says. At 10,000 robots, that's 300 million devices per year. For perspective, Apple sold about 160 million iPhones in the trailing 12 months. Of course, there is a possibility the robots may also be used for tablet production.

While the recent hire of 100,000 employees suggests Foxconn may not be deploying these robots soon enough to handle initial supply of the iPhone 6 lineup, it is still another sign Apple may be prepping for record iPhone supply.

3. Enormous sapphire display production capacity
Apple's upcoming line of iPhones is rumored to use sapphire crystal for the displays. While some rumors have suggested the smaller 4.7-inch iPhone 6 may not adopt the sapphire crystal yet, there's a consensus in the Apple rumor mill that, at least, the larger iPhone 6 will use the new technology.

Apple already uses sapphire glass to protect the camera in its iPhones and on the home button of the iPhone 5s for Touch ID.

PTT Research analyst Matt Margolis, who has followed Apple's investment in sapphire crystal closely, believes that Apple's sapphire crystal supplier could be readying for production as high as 200 million smartphone displays per year.

Considering these three reports, Apple appears to be preparing for a record year for its largest business segment. Analysts, too, are growing bullish on Apple's upcoming iPhone line. Could Apple's important iPhone segment soon return to 20% plus year-over-year growth, thanks to the larger iPhone 6 line?