Pen-type character recognition apparatus

• US 4,751,741 A
• Filed: 07/11/1985
• Issued: 06/14/1988
• Est. Priority Date: 07/19/1984
• Status: Expired due to Term

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Ogata, Yoshio, Mochinaga, Nobuyuki, Moto, Takashi
• Primary Examiner(s): Moore, David K.
• Assistant Examiner(s): Todd, Jacqueline
• Application Number:
  US06/754,394
• Time in Patent Office: 1,069 Days
• Field of Search: 382/13, 382/59, 364/705, 178/18, 340/706
• US Class Current: 382/188
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06V 10/12 Details of acquisition arrangements; Constructional details thereof

Abstract

A pen-type character recognition apparatus includes an input data detecting section for detecting input character data as data representing a certain character according to a change in pressure applied to a tip element of a pen. A data processing section standardizes the output data from the input data detecting section by compressing the output data to a predetermined number of data for the character, so as to generate corresponding standardized data. A data registering section registers in advance selected standardized data as standard pattern data for corresponding to the predetermined input character data when a character is written with the pen tip element, and an input character recognizing section recognizes the character represented by the input character data by comparing the standardized data generated from the data processing section with the data registered in advance in the data registering section.

Claims

1. A pen-type character recognition apparatus, comprising:

a pen-shaped, hand-held size housing having a tip element for writing a character;

a plurality of pressure detecting elements, which are associated with said tip element within said pen-shaped housing, for detecting pressure in accordance with at least x and y direction components perpendicular to an axis of said tip element, and for producing corresponding input character data;

input data detecting means for detecting the input character data as data representative of a certain character according to a change in pressure applied to said tip element;

said input data detecting means further including means for storing, in accordance with a change in one of the output signals from said plurality of pressure detecting elements, the output signal before changing as a reference signal;

an operational amplifier for amplifying the output signals from said plurality of pressure detecting elements and for supplying the amplified output signals to said storing means, said operational amplifier having an inverting input and an output;

a capacitor for supplying a bias voltage to said operational amplifier;

means for supplying a handwriting input signal to said inverting input of said operational amplifier through said capacitor;

a feedback resistor connected between said inverting input and said output of said operational amplifier through asid capacitor; and

a switching element for short-circuiting between said inverting input and said output of said operational amplifier in synchronism with a predetermined timing signal so as to charge an offset voltage of said capacitor;

electronic circuit means, coupled to said input data detecting means, for processing output data from said input data detecting means; and

display means for displaying said certain character represented by the input character data;

said input data detecting means, said electronic circuit means said display means being mounted in said pen-shaped, hand-held size housing;

said electronic circuit means comprising;

data processing means for standardizing output data from said input data detecting means, including means for compressing the output data to provide a predetermined number of data for said certain character;

mode signating means for selecting at least a registration mode and a recognition mode;

data registering means including first memory means for registering, in advance, selected standardized output data from sadi data processing means as standard pattern data for corresponding with the input character data when a character is written by said tip element, said output data from said data processing means being registered when said registration mode is selected by said mode designating means; and

input character recognizing means including means for calculating a correlation value and a maximum correlation value between the output data from said data processing means and data registered in said data registering means, and for recognizing the character represented by the input character data in accordance with said maximum correlation value when said recognition mode is selected by said mode designating means.

2. An apparatus according to claim 1, wherein said data detecting means includes means for storing, in accordance with a change in one of the output signals from said plurality of pressure detecting elements, the output signal before changing as a reference signal;

means for comparing the reference signal stored in said storing means and the output signals from said plurality of pressure detecting elements; and

means for sampling the output signals from said plurality of pressure detecting elements only when a difference signal from said comparing means is present.

3. An apparatus according to claim 2, wherein said input data detecting means first includes first control means for causing said storing means to continue a storing operation thereof only when one of the output signals from said plurality of pressure detecting elements changes during a predetermined period of time.

4. An apparatus according to claim 1, wherein said data processing means includes second memory means for storing output data from said input data detecting means;

means for reading out a preset number of data from data stored in said second memory means for said certain character in a redetermined sequence; and

third memory means or storing the data read out by said readout means.

5. An apparatus according to claim 1, wherein said apparatus includes means for updating an address of said first memory means of said data registering means by operating a skip key, when the output data from said data processing means is stored in said first memory means with said apparatus being in said registration mode selected by said mode designating means.

6. An apparatus according to claim 1;

wherein said apparatus includes correction designating means for selecting a correction operation of a recognition result from said input character recognizing means; and

control means for instructing calculation of a second maximum correlation value excluding the immediately preceding maximum correlation value with respect to said input character recognizing means.

7. An apparatus according to claim 1, wherein each of said plurality of pressure detecting elements is a semiconductor strain gauge including a semiconductor substrate;

a gauge resistor arranged on said semiconductor substrate in a first pressure sensitive direction and having a resistance changed in accordance with a strain; and

a dummy resistor, arranged on said semiconductor substrate in a second pressure sensitive direction substantially perpendicular to the first pressure sensitive direction and connected to said gauge resistor, for compensating for the precision of the resistance of said gauge resistor.

8. An apparatus according to claim 1, including means for performing an arithmetic operation in accordance with numeral data and function data which are recognized by said input character recognizing means, and for displaying the result of the arithmetic operation on said display means.

9. A pen-type character recognition apparatus, comprising:

write means including a pen tip element having an axis, for producing input character data in response to a change in pressure applied to said tip element;

input data detecting means associated with said write means for detecting the input character data as data representative of a certain character according to changes in the pressure applied to said tip element;

data processing means for standardizing output data from said input data detecting means, including means for compressing the output data to a predetermined number of data for said certain character so as to generate corresponding standardized data;

data registering means for registering in advance selected standardized data as standard pattern data for corresponding with the input character data when a data character is written said write means; and

input character recognizing means for recognizing the character represented by the input character data produced by said write means, including means for comparing the standardized data generated from said data processing means with the data registered in advance in said data registering means;

wherein said input data detecting means includes

a plurality of pressure detecting elements associated with said pen tip element for detecting a pressure in accordance with at least x and y direction components perpendicular to the axis of said tip element of said pen;

means for storing, in accordance with a change in one of the output signals from said plurality of pressure detecting elements, the output signals before changing as a reference signal;

means for comparing the reference signal stored in said storing means and the output signals from said plurality of pressure detecting elements;

means for sampling the output signals from said plurality of pressure detecting elements only when a difference signal from said comparing means is present;

an operational amplifier for amplifying the output signals from said plurality of pressure detecting elements and for supplying the amplified output signals to said storing means;

a capacitor for supplying a bias voltage to said operational amplifier;

means for supplying a handwriting input signal to an inverting input terminal of said operational amplifier through said capacitor;

a feedback resistor connected between the inverting input terminal and an output terminal of said operational amplifier through said capacitor; and

a switching element for short-circuiting between the inverting input terminal and the output terminal of said operational amplifier in synchronism with a predetermined timing signal so as to charge an offset voltage on said capacitor.