Barnes and Noble introduces the Nook HD family.

The firm today unveiled the 7-inch NOOK HD e-reader and the 9-inch Android-based NOOK HD+ (pictured), with prices starting at US$199 and US$269, respectively. It notes that the latter is nearly half the cost of “the leading large-format tablet” – Apple’s iPad.

“We designed our larger format tablet NOOK HD+ because we think there’s big demand from customers for a super-light, extremely high quality 9-inch tablet, at half the price of the iPad,” said CEO William J. Lynch.

The NOOK HD – touted as rival to Amazon’s Kindle - claims to offer “the highest-resolution display ever” on a 7-inch tablet at 1440 x 900. It is powered by a dual-core 1.3GHz processor. The HD+ boasts a 1920 x 1280 display and uses a 1.5GHz dual-core processor.

In terms of content, Barnes & Noble says the NOOK Store now offers more than 3 million books and “significant new additions and advancements to the NOOK content ecosystem.”

Among the new features is a service called Profile enabling a “personalised experience,” allowing the devices to be safely shared between family members - for example by blocking certain content from child profiles.

Both devices will be available in the US and UK later this year.