Optical character reader apparatus

• US 4,799,271 A
• Filed: 03/18/1987
• Issued: 01/17/1989
• Est. Priority Date: 03/24/1986
• Status: Expired due to Term

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Nagasawa, Hikoshi, Ito, Kazuo, Horii, Shigeru, Tanoshima, Katsuhide
• Primary Examiner(s): BOUDREAU, LEO H
• Application Number:
  US07/027,408
• Time in Patent Office: 671 Days
• Field of Search: 382/40, 382/30, 382/33, 382/34, 382/57
• US Class Current: 382/231
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/262 using context analysis, e.g. lexical, syntactic or semantic context

Abstract

An optical character reader apparatus is provided to optically read characters written on a document card to extract as a word a character group compared with previously registered words. Such a word is compared for each character constituting that word. When the number of constituent characters constituting the extracted word is greater than a prescribed number, a judgement is made as to whether or not each constituent character is a vowel, and, if so, is removed and, if otherwise, subsequently compared with respect to characters other than vowels. As a result, a word which is found to have the largest number of coincident characters to previously registered words, is selected as a candidate word and delivered as the word read from the document card.

Claims

1. An optical character reader apparatus comprising:

(a) an optical system for converting characters written on a document card to an optical signal and for converting said optical signal to an electrical signal;

(b) a pre-processing circuit connected to said optical system for converting said electrical signal into a binary picture image signal, and for extracting a picture image corresponding to one character from said binary picture image signal;

(c) a feature extracting circuit connected to said pre-processing circuit for extracting features of said one character in conformity with a predetermined procedure;

(d) a character judgement circuit connected to said feature extracting circuit for effecting a comparison of said one character;

(e) a dictionary memory connected to said character judgement circuit for previously registering feature data of characters corresponding to character codes of said characters, and for further enabling said character judgement circuit to compare said feature data from said feature extracting circuit with said feature data registered in said dictionary memory and for delivering character codes of coincident characters in response to said comparison;

(f) a post-processing circuit connected to said character judgement circuit and an output terminal for effecting editing and output control corresponding to said judgement in said character judgement circuit;

(g) a vowel judgement part connected to said word comparison control part for judging whether or not respective constituent characters of the extracted words are vowels when said number of characters constituting the word extracted in said word constituting character number judgement part is greater than a prescribed number, and if so, eliminating a constituent character judged to be a vowel from among said constituent characters being compared; and

(h) a word comparison circuit connected to said post-processing circuit for effecting word comparison in cooperation with said circuit.

2. An optical character reader apparatus according to claim 1, wherein said optical system includes:

(a) a document card conveyor mechanism for conveying a document card in conformity with a predetermined format;

(b) an illumination lamp for illuminating the document card;

(c) a focusing lens for focusing reflected light from the document card; and

(d) a photoelectric conversion sensor for converting light reflected from the document card to provide an electrical signal.

3. An optical character reader apparatus according to claim 1, wherein said word comparison circuit includes:

(a) a word dictionary memory for previously registering words in word tables therein while classifying said words for every number of characters constituting said word;

(b) a word comparison control part connected to said post-processing circuit and said word dictionary memory for controlling the word comparison;

(c) a word table selecting part connected to said word comparison control part for selecting at least one of said word tables in said word dictionary memory in response to the number of characters constituting an extracted word;

(d) a word-constituting character judgement part connected to said word comparison control part for judging whether or not the number of characters constituting the extracted word is greater than a prescribed number;

(e) a word comparison part connected to said word comparison control part for comparing the constituent characters of the extracted word yielded through said vowel judgement part with constituent characters of each word in said word table selected in said word table selecting part and for thereby evaluating the number of coincident characters; and

(f) a candidate word retrieving part connected to said word comparison control part for selecting as a candidate word, a compared word having the largest number of the coincident characters in said word comparison part.

4. An optical character reader apparatus according to claims 1, wherein the functions and controls of said post-processing circuit and said word comparison circuit are executed by a microprocessor circuit.

5. An optical character reader apparatus according to claim 3, wherein the functions and controls of said post-processing circuit and said word comparison circuit are executed by a microprocessor circuit.

6. An optical character reader according to claim 4, wherein said microprocessor includes:

an arithmetic logic unit for effecting arithmetic operation;

a microprogram memory for operating said microprocessor circuit in conformity with a microprogram stored therein;

an I bus composed of 16 signal lines for mutual connection of said arithmetic logic unit and said microprogram memory;

a sequencer connected to said microprogram memory for providing addresses of said microprogram memory;

a Y bus connected to said arithmetic logic unit for use in data delivery;

an I/O circuit connected to said Y bus; and

a decoder connected to said Y bus and said sequencer for generating a selection signal from two signals on the Y bus.

7. An optical character reader according to claim 5, wherein said microprocessor includes:

an arithmetic logic unit for effecting arithmetic operation;

a microprogram memory for operating said microprocessor circuit in conformity with a microprogram stored therein;

an I bus composed of 16 signal lines for mutual connection of said arithmetic logic unit and said microprogram memory;

a sequencer connected to said microprogram memory for providing addresses of said microprogram memory;

a Y bus connected to said arithmetic logic unit for use in data delivery;

an I/O circuit connected to said Y bus; and

a decoder connected to said Y bus and said sequencer for generating a selection signal from two signals on the Y bus.

8. An optical character reader apparatus according to claim 4, wherein said microprocessor includes:

an arithmetic logic unit for effecting arithmetic operation;

a microprogram memory for operating said microprocessor circuit in conformity with a microprogram stored therein;

an I bus composed of 16 signal lines for mutual connection of said arithmetic logic unit and said microprogram memory;

a sequencer connected to said microprogram memory for providing addresses of said microprogram memory;

a Y bus connected to said arithmetic logic unit for use in data delivery;

an I/O circuit connected to said Y bus; and

a decoder connected to said Y bus and said sequencer for generating a selection signal from two signals on the Y bus.

9. An optical character reader apparatus according to claim 1, wherein said I/O circuit includes:

a flip-flop connected to said character judgement circuit for storing a start signal from said character judgement circuit and transmitting it to said Y bus by the SEL 1 signal;

a candidate character code register connected to said character judgement circuit and the Y bus for storing a candidate character code delivered from said character judgement circuit and transmitting it to the Y bus by the SEL 2 signal; and

, in said word dictionary memory, a memory for storing words, an address register for assigning any address of the memory, and a data register for storing data from said memory, said address register incorporating therein data from said Y bus based upon the SEL 3 signal while said data register delivering the concerning data to the Y bus based upon the SEL 4 signal.