JPH0313788Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION Field of the Invention and Prior Art This invention relates to the production of x-y position measurements for use in, e.g., character recognition devices used in conjunction with writing machines, e.g., automatic graph recorders. The present invention relates to a correction device.

Writing machines, including automatic graph recorders, have been commercially available for many years. Automatic graph recorders typically include a case containing a chamber for receiving a bundle of folded interleaved continuous stationary webs, and a mechanism for feeding the continuous stationary web through the automatic graph recorder. The continuous fixed web consists of a top web and at least one underlying copy recording web. For example, a copying material such as carbon paper is sandwiched between a top web and at least one copy recording web below it, which means that data recorded on the top web is transferred to at least one copy recording web below it. This is to enable re-recording on one recording roll. The web is fed onto a writing board where data is manually written onto the web. As such data, business data can be recorded, but other data can also be recorded. When data has been recorded on the web, by operating a handle on one side of the writing machine, a sheet-length form of the web is fed out of the recorder, and the lower portion is filled with the web and folded. The fuel is then sent to the filling chamber where it is stored. Portable automatic graph recorders are also commercially available. Portable graph recorders generally include a compartment in which unused forms are stored and a writing board. In such portable recorders, a continuous fixed web is manually drawn from a storage chamber onto a writing board by an operator, and a sheet-length form of the continuous web of business forms is, for example, placed in a pair of positioners. The pins engage with positioning holes provided in the tip of each length of business form for an automatic graph recorder. An example of a portable automatic graph recorder is a British patent no.
1293677.

Character recognition devices have been proposed for automatically recognizing written characters. British Patent No. 863431 describes a device for recording the writing of handwritten characters on a supporting surface, an electrical circuit actuated by the movement of a writing instrument during the writing, and A means is described for recording written characters when activated. This device can be incorporated into an automatic graph recorder or other device for handwriting.

The device described in GB 1310683 is a device for obtaining signals representing the coordinates of a point. The device includes a sheet of resistive material and an electrically resistive member, which are not normally in contact with each other, but can be brought into temporary contact, for example, by use of a writing tool. Inside this device,
Switching means are provided for passing current through the sheet and the member in different directions at right angles to each other and thereby deriving a signal representative of the coordinates of the point.

The specification of British Patent Application No. 7943987 (European Patent Application No. 803045269, US Application No. 217130) describes a character recognition device. This character recognition device includes a writing pad consisting of a pair of sheets, which are normally electrically insulated from each other but brought into contact with each other by writing pressure applied to the writing pad by a writing tool. It's getting old. The character recognition device further includes an electrical switching circuit for alternately passing current through two current paths of the writing pad, and for recognizing written characters by changing the voltage in the alternating current paths. Contains recognition circuit. This character recognition device is characterized in that one sheet of the writing pad has a high-resistance central portion and a low-resistance frame, so that the potential gradient along the length of the writing pad is linear;
and the other of the sheets comprises a layer of conductive material.

SUMMARY OF THE INVENTION The object of the present invention is to provide an improved character recognition device that can be associated with a writing machine in such a way that handwritten characters on, for example, business forms in the character recognition device can be easily recognized and processed. It is an object of the present invention to provide an apparatus for correcting x-y position measurements for use.

According to this invention, in a device that generates an electrical signal representing the two-dimensional position coordinates of a movable member, for example for use in recognizing handwritten characters, a pair of electrical A substantially rectangular planar resistive sheet having a relatively high resistance value and having a frame portion having a relatively low resistance value forming a connecting connector portion; a switch device for repeatedly applying a potential alternately to one or the other of a pair of electrical connectors in order to form a resistor sheet; It has a device section for obtaining a measured potential and a device section that responds to the measured potential, and this device section is installed at each of a plurality of predetermined positions in order to measure the error in advance. for,
configured to derive a pair of correction values relating two potentials induced by the two currents measured at a predetermined location and flowing in mutually orthogonal directions to a potential to be generated as the potential at the predetermined location; and, furthermore, a digital memory for storing each of the above-mentioned calculated correction values, and a potential on the resistive sheet induced by the above-mentioned two mutually perpendicular currents at the position of the movable member. a device part for measuring the magnitude of the potential formed from the aforementioned resistive sheet on the basis of previous error measurements in order to generate an electrical signal representative of the true position coordinates of the movable member; and a computing device for combining the stored correction values with a selected one of the stored correction values.

With such a device configuration unique to the present invention, there is provided a device for correcting x-y position measurement values that can improve ease, simplicity, and processability when recognizing handwritten characters using a character recognition device, for example. It is possible to achieve the remarkable effect of being able to provide the following.

Next, a character recognition device embodying the x-y position measuring pad according to the invention will be described with reference to an example shown in the accompanying drawings.

PREFERRED EMBODIMENTS Figures 1 and 2 show an automatic graph recorder 1 comprising a filling chamber 2 for receiving a web 3 of interleaved continuous automatic graph recorder forms. . The web is transported from the filling chamber 2 to the writing pad 5 by a paper transport mechanism 6. The paper feed mechanism 6 has a pair of paper feed pins 6a that engage in a pair of holes adjacent to the longitudinal ends of each successive form of the web 3. The paper feed pin is mounted on a pivotable housing 6b which includes an operating lever 6c which projects through the case of the recorder 1. When this lever 6c is operated, the web is sufficiently stretched out from the recorder such that the leading end of the web protrudes sufficiently from the hole in the recorder so that the operator can grasp it and pull it out. The web is pulled through the recorder until the hole in the next form engages the paper feed pin 6a when the web feed is stopped.

A character recognition device is associated with the writing pad 5, and a display 4 is located at the output end of the recorder for displaying characters recognized by the character recognition device associated with the recorder and for providing instructions to the recorder operator. indicate.

The character recognition device includes a position-measuring pad located on the writing pad 5 and comprises a pair of sheets, one coated with a resistive coating and the other made of an electrically conductive material. These sheets are usually separated from each other and can be brought into temporary contact. In other words, when they come into contact, an electrical circuit involving the two sheets is created. Since the writing pad 5 is configured in this way, 2
When the sheets come into contact, a circuit is created through the sheets, so that the position of the point of contact between the two sheets can be determined by the measured voltage. Associated with the writing pad 5 are a voltage measuring device 35 and an associated current converter 36, as shown in FIG.
and a series of character recognition circuits 37 (programmed to help recognize the characters written on the web 3).

FIG. 3 shows one form 11 of the continuous fixation form, and the tip 13 of the next form 11a is separated from one form 11 by a series of cutting perforations. The business form is made up of several similar interleaved sections, only one of which is shown in FIGS. 3 and 4 and schematically illustrated in FIG. Each roll of business form is divided into several forms,
And each form for one piece has 1 part at its tip 13.
It has a pair of recorder holes. The business form is delivered from the recorder by means of a paper advance pin and web puller operated by manual operation of a lever. The method of operating a portable automatic graph recorder is described in detail in British Patent No. 1,293,677.

The length of each form is the same,
Each of them is divided into predetermined writing areas 14, 15, 16. As shown, area 14 is an address area for entering the customer's name, address, invoice number and date. The area 15 is divided into several separate sub-areas 15a, 15b, 15c, etc., and each sub-area is used to fill in details of the sales operation, such as details of the number of items in stock or names of items in stock, the number of items sold, unit price, and total amount. It is set as.

Sub-area 15a contains the specific instructions needed to record, along with areas for filling in details of all values for the entire business, as well as other miscellaneous information (e.g. value added tax, etc.).
It is now possible to enter the information along with the Area 16 is adapted to receive instructions relating to the operation of the recorder. As shown, these instructions are signaled to the Acceptance, Cancellation, and Daily Total instructions to indicate the total amount of goods sold in a day, the total amount of taxes due on that day's transactions, and the total amount of cash. including.

There is a scale mark 17 on the left side of the area 16,
This scale mark consists of a vertical line and a horizontal line (which touches the vertical line at its center point). The scale mark 17 cooperates with a coordinate position recognition device to locate the scale mark (to which marking pressure is applied by a pencil or other writing instrument) so that the position of the mark relative to the writing pad 5 is determined. obtain. The coordinate position recognition device will be explained later.

The writing pad or character recognition pad is spaced apart from the paper feed pin 6a in the recorder. The holes drilled in the business form are arranged in a predetermined relationship with each area 14, 15, 16 of the form. Thus, when a sheet of foam is stopped by the hole adapted to engage the paper feed pin 6a, each area 14 on the foam,
The scale marks 15, 16 and the scale marks 17 are arranged so as to be above respective predetermined positions on the writing pad 5. A sheet of foam is placed in a predetermined stop position with respect to the writing pad 5 and a mark (this may be, for example, part of a character in a selected one of the areas 14, 15, 16, 17) is placed. When pressure is applied to the form to create an electrical contact between the two sheets of the drawing and writing pad 5,
An electrical circuit is created through the two sheets. Accordingly, as shown in FIG. 3, the connected web 3 is arranged in a predetermined relationship with a hole in the recorder that coincides with the paper feed pin 6a. The paper feed pin 6a is the writing pad 5
and are arranged in a predetermined relationship.

The writing pad has a pair of spaced apart sheets;
The upper sheet is then connected by electrodes to appropriate switches 18 and power supplies 19, respectively.

FIG. 4 shows the writing pad 5. The write pad includes a rigid baseplate 21 of non-conductive material (such as the material commonly used as printed circuit board bases, such as the material known as glass fiber). This base plate 21 serves as a mechanical support for the writing pad. A layer of conductive connector material 23 is printed on baseplate 21 . The conductive connector layer material may be applied in the form of an etched copper layer similar to that used in printed circuit boards, or approximately 0.01 Ω per unit area.
may be applied as an ink containing silver particles to provide a coating with a resistance value of (hereinafter referred to as low resistance). The conductive connector coating is a medium resistance frame (described later)
to the connector 26 printed on the top edge.

A medium resistance frame layer 24 is printed on the low resistance conductive connector layer 23, and this medium resistance frame layer 24 completely surrounds the high resistance coating layer 25 (described later) and is located inside the low resistance conductive connector layer 23. Part on top. The medium resistance frame layer 24 is located on the low resistance conductive connector layer 23 at its four corners 23c.

The medium resistance frame layer shall have a width of 0.76 to 1.27 mm (30 to 50 mils) and be printed from an ink containing a mixture of silver and carbon particles to provide resistance values on the order of 1 ohm per unit area. I can do it. The medium resistance frame layer 24 is shown in black in FIG.

A high resistance coating layer 25 is printed on the baseplate shown in FIG. 4 within the frame formed by the medium resistance frame layer 24, but partially on the medium resistance frame layer 24;
This is indicated by a cross hatch. The high resistance coating layer 25 has a main rectangular portion within the medium resistance frame layer 24 .

The high-resistance coating layer 25, which has a resistance value of about 1000 Ω per unit area, can be printed with an ink containing a conductive material (preferably carbon or silver) and a resin, a plasticizer, and a solvent, and has a thickness of about 0.025 mm.
(1 mil).

In order to prevent the high-resistance coating layer 25 from peeling off during transportation or when putting it in and out of the character recognition device, the high-resistance coating layer 25 has a coating layer of about 100,000 per unit area.
A cover layer having a resistance value of Ω may be provided. This cover layer has the same structure as the high-resistance coating layer 25, but has a lower content ratio of conductive material and a smaller thickness.
Thinner than 0.025mm.

The low resistance conductive connector layer 23 has a series of connector areas (to external circuitry) disposed at the top edge of the write pad as shown in FIG. As shown, connectors 26 are located at the ends of the conductive wires to rectangular areas 23c adjacent each corner of the high resistance coating layer.
These connecting parts are connectors 26a, 26b, 26
c and 26d to rectangular areas 23c adjacent to each of the four corners of the rectangular resistance section 25.

Each high resistance coating layer 25 and each medium resistance frame layer 24 are formed by screen printing onto a sheet.
The thickness of these layers is approximately 0.025 mm or less.

Above and spaced from the high resistance coating layer 25 is an easily replaceable cushion layer in the area where the writing pressure is applied. This cushion layer 31 (Fig. 2)
The writing surface is intended to prevent electrical circuits from being created when the operator's hand contacts the writing surface, and usually consists of two thin layers made of electrically insulating material. Between these laminae is a layer of dielectrically nonconductive elastomeric gel material.

A suitable gel is available from Dow Corning under the trade name SYLGARDQ3.
It is commercially available as 6527. This material is supplied in two parts, Part A/Part B, and
A ratio of 1.65/1 to 1/1 is suitable. The thickness of the gel layer is 0.125-1.25 mm (5-50 mil), preferably 0.25-0.30 mm (10-12 mil).

The upper thin layer is a polymer film coated or treated with a low electrical resistance conductive material on the side closer to the elastomeric gel material, typically with a resistance of less than 1000 ohms per unit area. This may be a metal film or a conductive ink coating on a film, preferably a conductive ink screen printed on the underside of a flexible sheet. The conductive material in this thin layer is connected to the complete electrical connection and thus to the voltage measuring device via the conductive material in the electrical circuit described below.

The lower thin layer is a large conductive film with low electrical resistance laterally and high electrical resistance vertically. The ratio of lateral resistance to longitudinal resistance should be less than 1/100. Transverse resistance value per unit area
It is necessary to make the longitudinal resistance value smaller than 10,000 Ω and larger than 50,000 Ω per unit area.
Such a material may be a polymer-filled film containing a conductive material such as carbon, and is commercially available, for example, from 3M Company under the tradename VELOSTAT.
Such materials may also consist of elastomeric films, such as silicone films, containing well-dispersed nickel grains.

The upper and lower laminae are welded together at their respective peripheries, such as by heat sealing, to include elastomeric material between the sheets. Another flexible protective sheet may be a polyester film sheet disposed over the cushioning or conductive layer 31 and having a thickness on the order of about 0.025 mm (1 mil).

An electrical connection path is made between the upper lamina and the electrical circuitry external to the write pad. This connection is made via connector 26e near connectors 26b, 26c. Electrical connections are made using connectors 26a, 26
b, 26c, and 26d to the power supply 19, and from the connector 26e to the voltage measuring device 35.

An electrical switching circuit as shown in FIG.
Voltages are applied alternately between the connectors 26a and 26b and the voltage measuring device 35, and between the connectors 26c and 26d and the voltage measuring device 35 on the other hand. These connections cause current to flow through the resistive layer first in one direction and then in another direction perpendicular to the first direction.

The above-mentioned write pad 5 is provided between the connectors 26b, 26c on the one hand and between the connectors 26a, 26d on the other hand to create one electrical connection path.
and connectors 26b, 26 on the one hand for supplying alternately generated voltages across the write pad.
A two-dimensional potentiometer is formed due to the electrical connections made alternately between a and the connectors 26c, 26d on the other hand. Therefore, the upper lamina 3
1 and the main covering layer 25, a voltage is applied to the upper thin layer 31 and the main covering layer 2
represents the coordinates of the contact point on 5.

In the write pad shown in broken lines in FIG.
26c, 26a and 26d (FIG. 4). The switches are interlocked to move together and are configured such that connector 26c and rectangular area 23c are permanently connected to the power supply positive terminal and connector 26a and rectangular area 23c are permanently connected to the power supply negative terminal. . Connector 26b and rectangular area 2 in the switch down state where the X coordinate is measured.
3d and the rectangular area 23d are connected to the positive terminal, then the former is connected to the positive terminal, the latter to the negative terminal, and then in the switch-up state where the y-coordinate is measured, the former is connected to the positive terminal and the latter to the negative terminal. Ru.

A connection is made from the conductive layer on the thin layer 31 to a voltage measuring device 35 . This voltage measuring device is adapted to read the voltage (representing the x, y coordinates of the point indicating the writing position) applied across the resistive layer of the writing pad. Therefore, if the writing tool is recording a message on the writing pad at any time, the position of the writing tool can be represented by two voltages.

The voltage measuring device 35 is connected to a current exchanger or A/D exchanger 36, and a character recognition circuit or character processor 37 is configured to recognize characters in response to voltage changes corresponding to the above-mentioned distances x and y. ing.

Although interlock switch 18 is shown as mechanical, it could also be an electronic switch.

Although it is desirable that the voltage drop across the high resistance coating layer 25 be linear, if the coating is uneven, the voltage drop may not be exactly linear. An integrated circuit 38 is provided adjacent the write pad 5 to accommodate irregularities. The integrated circuit 38 includes a series of correction circuits associated with predetermined locations on the high resistance overlayer 25, each of which is operative to provide a correction signal when the associated write pad portion is operated. It will be done.

As shown in FIG. 4, the high resistance coating layer 25 is divided into areas surrounding the first speed point. High resistance coating layer 25
is provided with nine rows of points, each row having nine points. As shown in Figure 4,
There are three lines consisting of points 1 to 9, 10 to 18, and 19 to 27. These lines are evenly distributed on the writing pad. The high resistance coating layer 25 on the write pad is contacted by a matrix of multiple sense pins (not shown). These pins are arranged in nine rows of pins, each row having nine pins, the positions of the pins corresponding to points 1-9, 10-18, etc. as shown in FIG.

A series of pulses are sequentially applied to the matrix of pins, and the resistance of the high resistance coating layer 25 in the horizontal (x) and vertical (y) planes is measured.
The resistance value for the correction to be made to the particular point in question can then be calculated to linearize the voltage drop across the coating. To compensate for inaccuracies, an integrated circuit 38 containing a series of correction circuits is integrated into the high resistance overlayer 2.
5 has a correction circuit configured to match the required resistance value for each point on 5. The programmed circuit is associated with a correction circuit in the integrated circuit 38, so that when a character is written in an area near a selected one of several points, a correction code signal (which is (which is complementary to any error in the resistance value at a particular point on layer 25) is applied to voltage meter 35.

The address positions relate to correction signals for correction in the horizontal (x) plane and the vertical (y) plane for each of the 81 positions. Therefore, the position of the correction signal recorded on integrated circuit 38 may be related to the following.

1a: x correction term at position 1 1b: y correction term at position 1 2a: x correction term at position 2 2b: y correction term at position 2 3a: x correction term at position 3 3b: y correction term at position 3 4a: - 4b: - 81a: x correction term at position 81 81b: correction term at position 81 Since the interface 41 is connected to the character recognition circuit 37, when writing is performed on a specific part of the writing pad 5, the correction code signal is It is also applied to the character recognition circuit 37 so that calculations can be made to derive a corrected value representing the position of the writing instrument and hence the character being written. If you want to increase the accuracy, you can use 81 or more correction points.

FIG. 4 shows an embodiment of the correction device.
A programmable ROM (read only memory) integrated circuit 38 is included in the printed circuit board that forms the base of the write pad. A series of connections 39 connect the integrated circuit 3
8 and the connector 40. Connector 4
0 has 24 pins and therefore a connection to the integrated circuit 38.
It has 24 connections (although only 12 connections are shown in Figure 4 to simplify the drawing).

The first 11 of the 24 connections are address
The next eight pins are data pins. The 11 address pins can provide a total of 2047 different combinations, and the 8 data pins can provide a total of 255 types of data. Connection 39 serves to provide a connection between integrated circuit 38 and interface 41 and character recognition circuit 37.

Although specific embodiments of this invention have been described in detail above, all equivalents obvious to those skilled in the art are encompassed within the scope of this invention as claimed in the utility model claims.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a portable recorder embodying a character recognition device, FIG. 2 is a sectional view of the portable recorder, and FIG. 3 is a diagram of a continuous fixed format inserted into the character recognition device. FIG. 4 is a plan view of one writing pad forming part of the character recognition device. 23...Low resistance conductive connector layer, 31...Cushion layer, 5...Writing pad, 18...Switch, 34...Interlocking switch, 19...Power supply, 25
...High resistance coating layer, 38...Integrated circuit, 35...
Voltage measuring device, 36...A/D converter, 37...Character recognition circuit.

Claims (1)

[Claim for Utility Model Registration] In a device that generates an electrical signal representing the two-dimensional position coordinates of a movable member, a relatively low resistance value forming a pair of electrical connectors disposed on opposite sides of each other. a substantially rectangular planar resistive sheet of relatively high resistance value having a frame portion of the resistive sheet; a switch device section for repeatedly applying a potential to one or the other of the connector sections; and a device for obtaining measurement potentials induced by the currents at predetermined positions on the surface of the resistor sheet. and a device portion responsive to the measured potential, the device portion being configured to measure the predetermined potential at each of the plurality of predetermined positions in order to measure the error in advance. configured to derive a pair of correction values relating two potentials induced by the two mutually perpendicular currents measured at the position to the potential that should occur as the potential at the predetermined position; further comprising: a digital memory for storing each of the calculated correction values; and a digital memory for storing each of the calculated correction values; a device part for measuring the magnitude of the electric potential of said resistive sheet formed from said resistive sheet based on said previous error measurements to generate an electrical signal representative of the true position coordinates of said movable member; a calculation device for combining a potential magnitude with a selected one of the stored correction values.