1. Field of the Invention
The present invention relates to a portable information device; more specifically, it relates to a portable information device that allows a user to browse the Internet using a communication device and input information using a touch panel.
2. Description of the Related Art
In recent years, devices have become increasingly miniaturized and energy efficient, and because the telecommunications infrastructure has been built out, portable information devices that allow a user to access the Internet virtually anytime and anywhere have become common. Given this, it is expected that display devices known as tablet devices will become increasingly popular, because of their operability and portability.
With advances in wireless technology and energy efficiency technology, it is increasing common to see users, freed from network cables and power supply cables, using tablet devices. For this reason, tablet devices need to have an optimal interface to allow use in a variety of situations.
Furthermore, there is great variety in Internet content, including news articles that are primarily text, and moving images, such as video images. For the former, it is most natural and efficient for a user to view this on a screen that is longer vertically than horizontally, in the same manner that one reads the newspaper; for the latter, it is more natural to view this on a screen that is longer horizontally than vertically, as with television and movie screens. Therefore, it would be more convenient for a user to be able to choose the use mode depending on content, so that the tablet device screen could be used either vertically or horizontally.
Meanwhile, in supporting a tablet device, there are two conceivable cases: depending on whether a user is right- or left-handed and on use conditions, cases where a user will hold the device with the right hand, and cases where a user will hold the device with the left hand. Thus for these tablet devices, universal design considerations and increasing user convenience to allow for different ways of holding the device are important matters.
The display device disclosed in Japanese Laid-open Patent Application 2000-311174 is an example of the conventional technology for accommodating universal design. This display device is constituted so that the operational buttons can be for both left hand and right hand use, through the switching of display direction by means of an inclination sensor that senses inclination and at the same time switching the operational buttons to settings for either left hand use or right hand use, depending on the inclination direction.
However, this method has the problem of faulty operation when the user is lying down, as well as the problem of limitations on the situations in which a device can be used effectively.
The terminal device disclosed in Japanese Laid-open Patent Application 6-208433 offers means for appropriate viewing of a variety of content. In this invention, buttons are disposed around the periphery of the display, and depending on the positions on a touch panel that a user touches and the position in which buttons are touched, the functions of those buttons change. However, with this method, not only does cost increase because of the increased number of buttons, but it can be expected that a user will get confused as to which buttons to use.
Furthermore, for these kinds of tablet devices, the lighter they are, the more convenient they are; with the current technology, however, because of the weight of the battery unit and other factors, there are no devices sufficiently user friendly that they can be easily used with one hand, and thus these devices have not yet come into common use.