Character input device, image forming apparatus and character key display method

摘要

An input device comprises: an operation unit having a display part that can display a plurality of character keys and a touch screen; a subsequent input candidate search unit that, upon detection of contact to an area corresponding to a specific character key in the touch screen, searches among the input candidate string for an input candidate string with a first character being a specific character corresponding to the area thus detected, as a subsequent input candidate string; a subsequent input candidate determination unit that, with regard to the subsequent input candidate thus found, determines a subsequent character following the first character as a subsequent input candidate character; and a display exchange unit that displays a character key of the subsequent input candidate character thus determined, by exchanging with a character key arranged in the vicinity of a character key for the specific character as the first character.

主权项

1. A character input device comprising:
an operation unit having a display part that can display a plurality of character keys and an input confirmation key in a predetermined arrangement and a touch screen that is disposed on a front face of the display part; an input candidate storage unit that stores at least one string as an input candidate string; a candidate string search unit that searches among input candidate strings when a user touches an area corresponding to a character key corresponding to a specific character in the touch screen for a subsequent input candidate string which includes the specific character as a head character; a candidate character determination unit that determines a subsequent input candidate character following the head character with respect to the subsequent input candidate string thus searched; a display exchange unit that replaces a character key arranged in a vicinity of the character key corresponding to the specific character as the head character with a character key corresponding to the subsequent input candidate character thus determined and to cause the display part to display the character key corresponding to the subsequent input candidate character; and a counting unit that counts a total number of character keys arrangeable in the vicinity of the character key corresponding to the specific character as the head character each time the user touches the area corresponding to the character key corresponding to the specific character in the touch screen, wherein the total number of character keys thus counted varies according to a position of the character key corresponding to the specific character as the head character with respect to the display part, wherein the candidate character determination unit: extracts subsequent characters for all subsequent input candidate strings that are searched by the candidate string search unit; calculates a total number of types of the subsequent characters thus extracted; determines the subsequent characters of all the types as the subsequent input candidate characters, if the total number of types thus calculated is no greater than the total number of the character keys counted; calculates a probability of occurrence of a subsequent character of each type, if the total number of types thus calculated is greater than the total number of the character keys thus counted; and determines the subsequent characters as the subsequent input candidate characters in a descending order of the probability of occurrence, until the number of the subsequent characters reaches the total number of the character keys counted.