如何在阳光下看清液晶显示屏?

Technology columnist Walter S. Mossberg answers readers' questions.

Q: With summer coming, I will be outside a lot but still need to get some work done. Is there a laptop that you can read in direct sunlight?

A: To my knowledge, most consumer and business models use LCD screens with backlighting, which makes them wash out and harder to read in direct sunlight. Adding to the problem, most laptop screens have a glossy finish these days, which produces glare in strong light. But some companies still offer matte screens on certain models. You might look for one of those, though they won't entirely solve the problem. Another option is a stick-on, anti-glare shield. And, if you don't mind extra bulk and some clumsiness, there are even hoods you can buy to shield screens from the sunlight. There is another approach: Some 'rugged' laptops meant for outdoor workers have screens designed to be legible in sunlight.

Q: Does the iPad have any drawbacks as a reading device when compared to the Kindle? Does it have access to all the same book downloads as Kindle?

A: Yes. It weighs 1.5 pounds -- more than twice what the smaller, standard Kindle weighs. And even its impressive 11.5 hour battery life is much less than the Kindle's battery life, which is a week, because of that device's low-power monochrome screen. Also, Apple's iBooks store has many fewer titles available than Amazon.com's Kindle store.

However, you don't necessarily have to choose. Amazon has released a free Kindle app for the iPad that allows you to buy and read Amazon's larger catalog of e-books on the Apple device's bigger, brighter, color screen. Like other Kindle software -- for the PC, Mac, iPhone and BlackBerry -- this new iPad app obviates the need for Kindle hardware to access the Amazon e-book collection.

Q: If you have an iPhone or iPad, why does Apple recommend you use iTunes to back up data like calendar, contacts, bookmarks and apps to your computer, when iTunes is a player for music and video?

A: Yes, iTunes used alone is meant to organize and play music and videos. But Apple has also built into it the ability to manage the backing up and synchronizing of other sorts of data between its portable devices and the computer. It's also the method by which users upgrade the operating systems on iPhones and iPads and can be used to buy apps for those devices and transfer them over.