Information acquisition method and apparatus
AssigneeKabushiki Kaisha Toshiba
InventorsNaoki Tomita, Tomio Sakata
Life of this patent
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Abstract
The present invention is directed to detecting information such as characters or the like formed on a form using fluorescent ink without using any special components such as a light source for emitting ultraviolet light, an optical filter for intercepting transmission of ultraviolet light, or the like. When visible light which is emitted by fluorescent ink excited upon being irradiated with ultraviolet rays is detected by an image sensor, a level of the output photoelectrically converted by the image sensor is saturated and assures a level higher than white level as white reference, so that information such as characters or the like formed on a form using fluorescent ink can be acquired.
Claims12
A method of acquiring information from a form on which the information is recorded using fluorescent ink, comprising the steps of:
- irradiating the form with light which is emitted by a white light source, the light containing near ultraviolet light;
- outputting an analogue signal according to an amount of light reflected by the form;
- converting the output analogue signal into a multi-level digital signal;
- detecting from the digital signal a reference level of the digital signal corresponding to a position of the form where no information is recorded;
- and
- comparing a level of the digital signal corresponding to the information recorded using fluorescent ink with the reference level, and binarizing the digital signal based on a result of the comparison to obtain image information.
An apparatus for acquiring information from a form on which the information is recorded using fluorescent ink, comprising:
- a white light source for irradiating the form with light containing near ultraviolet light;
- photoelectric conversion means for outputting an analogue signal according to an amount of light reflected by the form;
- A/D conversion means for converting the output analogue signal into a multi-level digital signal;
- reference level detection means for detecting from the digital signal a reference level of the digital signal corresponding to a position of the form where no information is recorded;
- and
- binarization means for comparing a level of the digital signal corresponding to the information recorded using fluorescent ink with the reference level, and binarizing the digital signal based on a result of the comparison to obtain image information.
A character recognition apparatus for recognizing characters from a form on which the characters are recorded using fluorescent ink, comprising:
- a white light source for irradiating the form with light containing near ultraviolet light;
- photoelectric conversion means for outputting an analogue signal according to an amount of light reflected by the form;
- A/D conversion means for converting the output analogue signal into a multi-level digital signal;
- reference level detection means for detecting from the digital signal a reference level of the digital signal corresponding to a position of the form where no information is recorded;
- binarization means for comparing a level of the digital signal corresponding to the information recorded using fluorescent ink with the reference level, and binarizing the digital signal based on a result of the comparison to output image information;
- and
- recognizing means for recognizing the form as being recorded using the fluorescent ink based on the image information output from said binarization means.
A character recognition apparatus for reading characters from a form on which the characters are recorded and recognizing the read characters, comprising:
- fluorescent ink detection means for detecting whether or not one of a character and a mark is recorded on a form using the fluorescent ink;
- and
- rejecting the form in a case where said fluorescent ink detection means detects that the one of the character and mark is recorded on the form using the fluorescent ink.
Dependencies are inferred from the claim text.