New use for e-ink in cell-phones

[NatCh]

This tip comes from grimo1re

Japanese Company Looks at Using E-Ink in Cell-Phone Keypads

DoCoMo, which is apparently big in the Japanese cellular market, is looking at using e-ink technology to allow cell-phone keypad labels to change with the application being used. I.e. numbers for phone calls and letters for messaging.

The cellular carrier showed off prototypes of a phone with an e-paper keypad at the Ceatec exhibition in Chiba, Japan, this week. But the displays, from SiPix Imaging Inc., are not yet ready for commercialization in phones, said Shuichi Aoki, an assistant manager in DoCoMo's Product Department who helped developed the phone.

The prototype phone, which has been in development for about one year, has a keypad that switches the display on each key from numbers to Japanese phonetic characters, called hiragana and katakana, depending on what application is being used. For example, when a user opens the e-mail client, the keypad switches from numbers to the phonetic characters, making them easier for users to see, Aoki said.

Once you get to thinking about it, the usefulness of such a move would be pretty mind-boggling, particular for those who find the present arrangement confusing.

Apparently they're still pretty early in the process, and they're encountering some of the same obstacles that everyone else is with this e-ink stuff.

Before e-paper can be used in handsets, more work must be done to improve the technology. In particular, the response time of the e-paper display must be improved so that the symbols and icons used with each key change faster when switching between applications.

"It's a little too slow right now," Aoki said.

DoCoMo also wants to switch from using segmented e-paper displays to an active-matrix display for future prototypes. The current prototype uses a segmented e-paper display, which limits the display to pre-set characters, numbers and symbols.

An active matrix display will allow any symbol or letter to be displayed, and allow applications to use their own, customized icons instead of drawing on a pre-determined list of available options, Aoki said.

It's not mentioned, but I expect they're also encountering (or will shortly) the conflict between backlights and e-ink -- perhaps they'll come up with something clever and solve that problem for us all.


I think this is the first time I've encountered anyone trying to use e-ink to explicitly re-purpose controls on something like this. It brings hardware controls a bit closer to software ones, such as in an application GUI. Even though it's still years away, it's a very interesting development.


Source

[IceHand]

The idea is not new, I think there's a PC keyboard which uses small LCD's to display different symbols on the keys. Alas the keyboard is damn expensive and using that many LCD's in a cellphone would drain the battery way too fast. So obviously E-Ink is the way to go.

[NatCh]

Originally Posted by IceHand

The idea is not new ....

Oh, I knew the idea wasn't new, I think I've seen some TV remotes which do something like this. I meant to say that I think it's the first use of e-ink this way.

[IceHand]

Well, that's true

[nekokami]

I can really see this being critical in Japan, since their writing system is so complex.

[grimo1re]

Yeah, NTT DoCoMo (part of Nippon Telephone & Telegraph, NTT) is big in Japan. The mobile operator has about 53 million customers. To compare: rival KDDI has almost 29 million subs, Softbank Mobile (previously Vodafone KK) has about 17 million customers, newcomer Emobile has 122,300 subscribers and PHS provider Willcom has 4.6 million customers. (Figures from the Telecommunications Carrier Association in Japan)

[HarryT]

Originally Posted by NatCh

Oh, I knew the idea wasn't new, I think I've seen some TV remotes which do something like this. I meant to say that I think it's the first use of e-ink this way.

I'm not sure I see the advantage of eInk for this over a touch-sensitive LCD screen. As you say, this is a common approach used by "universal remotes" which can be configured to control multiple devices - you choose the device, and the layout of the rest of the screen changes accordingly. I have one myself, and it runs off a couple of AA batteries for months. I wonder what the perceived benefit of eInk is?

[NatCh]

Originally Posted by HarryT

I'm not sure I see the advantage of eInk for this over a touch-sensitive LCD screen. As you say, this is a common approach used by "universal remotes" which can be configured to control multiple devices - you choose the device, and the layout of the rest of the screen changes accordingly. I have one myself, and it runs off a couple of AA batteries for months. I wonder what the perceived benefit of eInk is?

I see what you're saying, HarryT, but look at it from this perspective -- the average cell phone gets ... what? 3~5 hours of talk time, and ~2 weeks of standby time on a charge? In that environment, adding an LCD gets a bit more burdensome on the battery, while adding e-ink should have very little impact on the battery life.

Also, that TV remote can be depended on to only be used in a fairly limited range of lighting, where the cell phone has to work in a much broader range, so any LCD (particularly on the button labels) would have to be a lot brighter, which translates to more power.

[HarryT]

True - all very good points!

[JSWolf]

What cell phones should have is a solar panel built in so they can charge whil you roam outside on the phone.

[NatCh]

Heh, with all the things you want to put solar cells on, JSWolf, you'd do better to put them on your hat, and just have connectors to charge the various devices.

[JSWolf]

But I don't want the wires.

[NatCh]

Picky, picky, picky.

[jbenny]

Originally Posted by JSWolf

But I don't want the wires.

Just do a Tesla and beam the electricity