Pattern Processing Apparatus

Abstract

Information regarding a pattern being identified is obtained by means of a photoelectric connector comprising a photoelectric surface on which a photoinput image of the pattern is to be projected, focusing means for focusing photoelectrons emitted by the photoelectric surface in response to the photoinput image to form a photoelectron image on a focal plane, means to enlarge or reduce the photo-electron image, deflecting means for moving the position of the photoelectron image in the focal plane, an array of a plurality of electron beam detecting elements which are arranged in a plane near the focal plane, each electron beam detecting element generating a current proportional to the quantity of the electron beam impinging thereupon, and a plurality of parallel output conductors respectively connected to the electron beam detecting elements. The outputs on the output conductors are processed to identify the pattern.

Description

This invention relates to apparatus for identifying patterns, and more particularly to a photoelectric converter and pattern processing apparatus utilized in the identifying apparatus.

Heretobefore a flying spot scanner, vidicon or the like has been used as the photoelectric converter in the apparatus for identifying patterns. In all these prior art photoelectric converters since the signals are produced by scanning the photoelectric converter with an electron beam output signals are derived out in succession. For this reason, it is difficult to spacially process the signals with high resolutions.

Identification of a pattern, for example, involves the process of detecting necessary informations over a wide field of view. In the case of a letter read out device, it is necessary to detect the positions of the letters printed on a document of the standard size and to accurately read the letters. To increase the resolution in such a case, it is necessary to use a number of scanning lines of the order of about 2000 to 4000 lines per picture which is about 5 to 10 times larger than that of the scanning lines used in television cameras. For this reason, use of such a large number of scanning lines is not practical.

However, the resolution is not required to be so high provided that the photoelectric converting apparatus can operate at high resolutions at important portions of the pattern and can freely control such positions and resolutions just in the same manner as the human eyes even though the overall resolution of the photoelectric converter may be relatively low. "Variation of the resolution at a point" means the adjustment of the degree of obscure which corresponds to a mathematical operation for obtaining the sum of weights of the informations about that point. To this end, it is necessary to parallely derive out signals produced at the light receiving surface which is impossible with the prior art photoelectric converter of the point scanning type. To obtain the sum of weights by means of an electric circuit it is nesessary to temporarily store the informations in high quality delay lines. However, with this method it is not only difficult to process the signals at high speeds but also requires complicated and expensive circuits. In the prior art apparatus, in order to normalize the object to be read out it has been necessary to store the output from the phototelectric converter in a plane register and then shift the stored image in the vertical as well in the horizontal directions thereby normalizing the position of the image or to simultaneously detect several bits of the register and then compress them into a single bit thereby normalizing the size.

This method also requires special registers and a complicated device for controlling the register.

It is an object of this invention to provide a new pattern identifying apparatus having a pattern read out device which operates under a new principle quite different from the prior art device.

The pattern identifying apparatus of this invention is characterized in that it includes a phototelectric converting device capable of simultaneously deriving out video signals and is not required to use electron beam scanning.

The photoelectric converting device relates to an improvement of the so-called image dissector. Instead of scanning a photoelectron image on a target with an electron beam as in the image orthicon, in the image dissector, the entire photoelectron image is moved on the photoelectric surface to derive out an electron beam emanated from the photoelectric surface in accordance with an optical image through a minute opening at a fixed point and the taken out electron beam is amplified by a multiplying tube so as to serially take out picture signals.

In accordance with the photoelectric converting device of the invention, an array of a plurality of electron beam detecting elements are substituted for the opening of the image dissector for deriving out in parallel the picture signals in a given area. Further, this photoelectric converting device is provided with means for moving the phototelectron image formed on the array of the electron beam detecting elements to any desired position and means to enlarge or reduce the size of the photoelectron image. The outputs from the photoelectric converting device are derived out in parallel as picture signals of a given area over a plurality of output conductors and the derived out picture signals are then processed. For example, these pulurality of output conductors are connected to a characteristic portion detecting circuit to determine that which one of the output conductors carries the characteristic portion of the picture signals. The photoelectron image is enlarged or reduced until a desired size of the characteristic portion of the picture image is obtained, and the deflector device is controlled such that the characteristic portion is always maintained in the field of view of the photoelectric converting device. According to another method of processing the output signals, the parallel outputs from the photoelectric converter are applied to a mask signal forming circuit for detecting a particular output conductor which carries the picture signals, and the detected informations are used to control the enlarging and reducing means and the deflector means of the photoelectric converter thereby normalizing the position and magnitude of the picture signal and determining the picture signal to be identified.

According to this invention, various processing operations of the pattern such as the search of the portion to be identified, the normalization of the position and magnitude or the like which are required for the identification of the pattern can be made optically thereby greatly simplifying the pattern identifying apparatus. Moreover, it is possible to greatly improve the resolution over the prior art apparatus by the search, enlarging and reducing operations of the objects being identified.

The present invention can be more fully understood from the following detailed description when taken in connection with reference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic longitudinal sectional view showing the construction of a photoelectric converter constructed in accordance with the invention;

FIGS. 2A and 2B are a front view and a sectional side view respectively showing one example of the array of electron beam detecting elements of the photoelectric converter shown in FIG. 1;

FIG. 3 is a block diagram of a pattern processing apparatus embodying the invention;

FIG. 4 is a block diagram showing the construction of the deflection control circuit shown in FIG. 3;

FIG. 5 is a perspective view, partly in block form, of a modified pattern identifying apparatus;

FIG. 6 is a block diagram showing the mask shaping circuit shown in FIG. 5;

FIGS. 7A through 7F are diagrams for explaining successive steps of processing the pattern with the pattern identifying apparatus shown in FIG. 5;

FIG. 8 is a block diagram showing the construction of the deflection control circuit shown in FIG. 5;

FIG. 9 is a block diagram showing the construction of a connector circuit utilized in the circuit shown in FIG. 5; and

FIG. 10 is a block diagram of an isolating circuit utilized in the circuit shown in FIG. 5.

With reference first to FIG. 1, the light from an object 11 to be identified is focused on a photoelectric surface 13 by means of an optical system 12. Electrons are emitted from the photoelectric surface 13 in accordance with the light image of the object 11 and the electrons are accelerated by a cylindrical electrode 14 and are then focused by the first and second focusing coils 15 and 16 to form a photoelectron image 17 on the focal plane of the focusing coils. By supplying different currents to discrete focusing coils 15 and 16 it is possible to enlarge or reduce the photoelectron image thereby providing the so-called zooming action.

The position of the photoelectron image is moved by the action of the deflection coil 18. Although not clearly shown in the drawing the deflection coil 18 comprises a horizontal deflection coil and a vertical deflection coil so that it is possible to shift the position of the photoelectron image 17 by supplying currents of suitable values to these two coils. An array of the electron beam detecting elements 19 is disposed near the focal plane on which photoelectron image 17 is focused. This array 19 comprises a two dimensional array of a plurality of detecting elements 19.sub.11 through 19mm as shown in FIG. 2A. In the illustrated example, the electron beam detecting elements comprise semiconductor diodes. However, it should be understood that any small detecting elements may be used. As shown in the sectional side view of the array of the detecting elements 19 shown in FIG. 2B, a plurality of n-type regions 21 are formed by diffusing an n-type impurity in to the surface of a p-type silicon semiconductor substrate 20 to form a plurality of p-n junction diodes.

Metal electrodes 23 are applied onto respective n-type regions through an insulator film 22 and the electrodes 23 are connected to a plurality of parallel output conductors 24. Such semiconductor diodes manifest electronic multiplying function when photoelectrons are accelerated and caused to collide upon the junctions at a high speed. Also phototransistors can be used as the electron beam detecting elements. By the progress of modern integrated circuit technique it is possible to fabricate these semiconductor detecting elements to have sufficiently small size and at a high density.

Although the number of the detecting elements constituting the array is different dependent upon the requirements of the applications, a practical array for a pattern identifying purpose is 16 .times. 16 or 32 .times. 32. Further, the array is not limited to two dimensional type but a sigle dimensional array can also be used.

The size of the array of the electron beam detecting elements 19 is not always required to entirely cover the photoeletron image 17 but may be designed to cover only a portion thereof. In the following description, the portion of the picture image which is to be detected by the array of the detecting elements 19 is termed the "field of view" of the phototelectric converter.

In the photoelectric converter of this construction electrons emitted from the photoelectric surface 13 and accelerated by electrode 14 enter the semiconductor substrate 20 to form electron-hole pairs therein whereby currents flow through output conductors 24 corresponding to the portions of the semiconductor substrate which have received the electron beam. In this manner, the photoelectron image focused on the array of the detecting elements 19 is converted into electric signals which are simultaneously derived out in parallel through output conductors 24.

In this photoelectric converter, it is possible to vary the magnitude of the photoelectron image focused on the focal plane including the array of the detecting elements 19 by adjusting the currents flowing through the first and second focusing coils 15 and 16. Since the magnetic field generated by a coil is proportional to the current flowing therethrough it is possible to enlarge the photoelectron image formed on the focal plane by increasing the current flowing through the first deflection coil 15 and by decreasing the current flowing through the second deflection coil 16. If the currents flowing through the first and second deflection coils are varied in the opposite manner, the size of the photoelectron image is reduced. Obscure of the image caused by such current adjustment can be compensated for by a fine adjustment of the voltage impressed upon the acceleration electrode 14.

Such a zooming can be readily provided by any well known electronic circuit.

The position of the photoelectron image 17 on the focal plane can be adjusted by means of deflecting means 18. Such adjustment of the position of the electron image 17 can be made with any well known means capable of adjusting the values of the currents supplied to the horizontal and vertical deflection coils. It is also possible to gradually or quickly vary the position of the photoelectron image 17. More particularly, when a DC current which does not change with time is applied the photoelectron image is held standstill. On the other hand, if a current which varies with time, for example, a saw tooth wave current identical to the output of the deflection circuit of a television receiver, were applied the photoelectron image will move in both horizontal and vertical directions. With such a saw tooth wave current, image signals produced by scanning the photoelectron image appear on the output conductors 24. However, in the photoelectric converter since the array of the electron beam elements occupies a relatively large area it is possible to scan each one frame with a saw tooth wave having a lower frequency than that utilized in the conventional television receiver.

By using such deflecting and zooming devices it is possible to observe any portion of the object with any magnifying power or the entire portion of the object. In other words, when the photoelectric converter is incorporated into the pattern identifying apparatus, it is possible to firstly observe a wide portion of the object with a low resolution and then observe a particular portion of the object with a higher resolution by zooming up that portion into the entire area of the field of view.

FIG. 3 depicts the construction of such a pattern identifying apparatus which is constructed to perform pattern identification of cells. In the diagnosis of canser or other marignant tumors at their early stage, the configuration, size and concentration of the cells are observed. However, it takes a great labour to find out a particular cell among numerous cells, so that it is desirable to carry out this operation with a pattern identifying apparatus. To identify the pattern of the cells, the cells are dyed and are then photographed with a microscopic camera. In such microscopic pictures, the nuclei of the cells have larger concentrations than the surrounding portions. This tendency is remarkable in the malignant cells.

Referring now to FIG. 3, the parallel outputs from photoelectric converter 31 are quantized by means of a quantizer circuit 32 to form binary signals corresponding to the black and white levels. The output from the quantizer circuit 32 is applied to a detecting and isolating circuit 33 to isolate the portion of the pattern to be identified. The output from the detecting and isolating circuit 33 is supplied to an identifying circuit 34. The output from the photoelectric converter 31 is also supplied to a maximum value detecting circuit 35 to provide on an output conductor 36 the maximum signal output out of a plurality of parallel outputs. This maximum output signal is supplied to difference detecting circuits 37.sub.1 through 37.sub.5 where it is compared with the respective outputs from the photoelectric converter 31. The difference detecting circuits 37 operate to compare two analogue inputs for generating a high level output signal when the inputs have equal magnitudes, whereas when the two inputs have different magnitudes, or where the input signal is smaller than the maximum value the difference detecting circuits generate a low level signal. The high level signals is transformed into a "1" signal and the low level signal into a "0" signal by the operation of a group of quantizing circuits 38.sub.1 through 38.sub.5. Thus, the outputs from the quantizing circuits 38 determine which one of the output conductors 39 of the photoelectric converter 31 carries the maximum output. In the illustrated case, since the output from quantizing circuit 38.sub.2 is 1, it can be determined that output conductor 39.sub.2 from the photoelectric converter 31 carries the maximum output. Actually there are 32 .times. 32 output conductors 39 which are arranged in a matrix, but for the sake of brevity, only five conductors are shown in FIG. 3. As above described, these output conductors 39 are respectively connected to corresponding ones of 32 .times. 32 electron beam detecting elements shown in FIG. 2, the particular one of the quantizing circuits 38 which provides a 1 output determining that which one of the electron beam detecting elements in the array or which one of the positions in the field of view corresponds to the maximum concentration. Responsive to the outputs from the quantizing circuits 38, a deflection control circuit 40 produces a deflection current applied to the deflection device 41 of the photoelectric converter 31. In the illustrated example, the X and Y deflection currents are determined such that the detected point of the maximum concentration is brought to substantially the center of array of the electron beam detecting elements or the field of view.

FIG. 4 illustrates one example of the construction of the deflection control circuit. Input signals to the deflection control circuit are applied to an encoder 401 which is constructed to give to its output coordinate values corresponding to a position at which an input signal 1 or the maximum signal presents. Thus, an abscissa value X of the maximum signal is provided on an output conductor 402, whereas an coordinate value Y of the maximum signal is provided on an output conductor 403, respectively, in the form of digital signals. These rectangular coordinate informations are applied to a horizontal deflection coil 406 and a vertical deflection coil 407 of the photoelectric converter respectively through digital-analogue converters 404 and 405 and amplifiers 406 and 407. When the center of the field of view is aligned with the origin of the rectangular coordinate, it is possible to always position the maximum signal at the center of the field of view.

Referring again to FIG. 3, the output from the maximum value detecting circuit 35 is supplied to a threshold value circuit 42 which produces an output supplied to a zooming command circuit 43 when the output from the maximum value detecting circuit 35 exceeds a prescribed definite value. The zooming command circuit 43 applies a zooming command signal to a focus control circuit 44 which is constructed to apply to the focusing device 45 comprising the first and second focusing coils shown in FIG. 1 currents of a predetermined ratio for zooming up the photoelectron image to a desired size.

At the same time, the output from the zooming command circuit 43 is applied to the identifying circuit 34 to set it into operation. When the identifying circuit 34 completes its identifying operation, a termination signal is generated which is applied to the focus control circuit 44 to remove the zooming thus returning the photoelectric converter to the original condition.

With the photoelectric converter, it is possible to identify the pattern at high accuracies by firstly observing the entire portions of the object to be identified in the field of view, moving the point of the maximum concentration to the center of the field of view, and then enlarging this characteristic point to occupy the entire field of view by zooming. For this reason, it is possible to enlarge and identify the particular characteritic point at sufficiently high resolutions with an array of the electron beam detecting elements of the number of only 32 .times. 32, that is having a relatively low resolution.

Although in the embodiment shown in FIG. 3, the concentration of the picture image is used as the characteristic feature of the pattern being identified, it is also possible to use another characteristic feature of the pattern, such as its configuration, size or colour. In such case, the maximum value detecting circuit 35 is of course substituted by a circuit for detecting a particular configuration, size or colour of the pattern. Any one of many well known detecting or identifying circuits can be used for this purpose.

When detecting the characteristic points by firstly reducing the photoelectron image for bringing a relatively large portion of the object into the field of view it is possible to move accurately determine the characteristic point by searching the same by adjusting the focusing device to shift the focal point, thus obscuring the photoelectron image. The adjustment of the focal point can be made electrically by means of the focusing coil and the accelerating electrode as shown in FIG. 1. Where it is desired to roughly detect the characteristic feature of the object projected in the field of view, if the feature is identified too indetail, the identification is rather incorrect so that it is advantageous to search the characteristic point of the object while it is optically obscured.

While in the foregoing description the size of the image of the object was firstly reduced and then enlarged it is also possible to enlarge the image to detect a characteristic point such as a space between adjacent letters and to apply the detected space to the detecting and isolating circuit 33 for isolating a particular letter to be identified. Thereafter, the letter is enlarged to a size required for identification. For this reason, in this specification the pattern identifying circuit, the detecting and isolating circuit and the circuits associated therewith, which are imparted with the signal of an enlarged or reduced picture image, are generally termed a pattern processing circuit.

FIG. 5 illustrates the construction of a modified pattern identifying apparatus which utilizes the photoelectric converter shown in FIGS. 1 and 2 for normalizing, detecting and isolating the picture image signal of the object being identified.

In FIG. 5, the photoelectric converter shown in FIG. 1 is designated by a reference numeral 51. The parallel outputs from the photoelectric converter 51 are supplied to a quantizing circuit 53 over a plurality of output conductors 52.sub.1. The quantizing circuit 53 operates to quantize the respective outputs on output conductors 52, for transforming these outputs into a 1 or 0 signal in accordance with black and white levels. The outputs from the qunatizing circuit 53 are applied to a matrix circuit 54 which is constructed to detect the portion of the field of view at which the pattern signal resides for the purpose of deriving out the portion containing the pattern signal from the parallel outputs of the photoelectric converter 51, the detail of the construction of the matrix circuit 54 being illustrated in FIG. 6.

5 .times. 5 points 52 which are arranged in a matrix as shown in FIG. 6 respectively correspond to output conductors 52.sub.2 shown in FIG. 5 the conductors being shown to extend at right angles through the sheet of the drawing in FIG. 6.

The outputs on the output conductors 52 belonging to respective rows of the matrix are supplied to output conductors 56 through associated OR circuits 55. In the same manner the outputs on the output conductors 52 belonging to the respective columns of the matrix are supplied to output conductors 58 through associated OR circuits 57.

The outputs on the row output conductors 56 of the matrix circuit 54 are coupled to a vertical mask register 59, shown in FIGS. 5 and 6, which comprises five registers in the form of flip-flop circuits, for instance, which are respectively connected to the row output conductors 56. The column output conductors 59 of the matrix circuit 54 are connected to the flip-flop circuits of respective orders of magnitude of a horizontal mask register having the same construction as the vertical mask register.

As a result, the horizontal mask register 60 forms a horizontal projection signal of the image signal 1 presenting in the field of view, whereas the vertical mask register 59 a vertical projection signal. These conditions are shown in FIG. 7B, in which the shaded portions of the vertical and horizontal registers 59 and 60 indicate the projection signal 1 applied to the flip-flop circuits. FIG. 7A shows the relationship between an array of digits which are the patterns to be identified and the field of view 19 of the photoelectric converter 51, while FIG. 5B the array of digits in the field of view of the photoelectric converter 51. FIGS. 7B through 7F show outputs from the photoelectric converter 51 as seen through a portion of the matrix circuit 54.

In this manner, when the projection signals are applied to the vertical and horizontal mask registers 59 and 60, an identification termination signal is applied to the deflection control circuit 61 shown in FIG. 5 from an identifying circuit to be described below. In response to this termination signal, the deflection control circuit 61 operates to control the deflection device of the photoelectric converter 51 thereby shifting the digits in the field of view toward upper and left as shown in FIGS. 7C and 7D.

This operation will be described in detail with the aid of FIG. 8.

The identification termination signal from the identifying circuit 76 is applied to the set input terminals of a flip-flop circuit 611 to produce a signal on the output terminal 1 thereof. This output is used to enable a gate circuit 612. The output pulse from a clock signal generator 613 is applied to an X-coordinate counter 614 via the enabled gate circuit 612. The X-coordinate counter 614 counts the number of clock pulses to apply its result to a digital-analogue (D-A) converter 616 through an adder 615. The output from the D-A converter 616 is applied to the horizontal deflection coil of the photoelectric converter through a deflection amplifier 617. Thus, while the gate circuit 612 is enabled, the content of the X-coordinate counter 614 increases with time to gradually increase the deflection current. This will shift the photoelectron image of the photoelectric converter to the left. When the projected signal in the horizontal mask register 60 reaches the righthand end as shown in FIG. 7D, the lefthand detector 63 produces an output which is applied to the reset terminal R of flip-flop circuit 611, shown in FIG. 8. When this flip-flop circuit 611 resets, gate circuit 612 is disenabled, and a signal is produced on output terminal 0 of the flip-flop circuit 611. This output signal is used to set a second flip-flop circuit 618. The 1 output of the second flip-flop circuit 618 enables a second gate circuit 619 to apply the pulse signal generated by clock pulse generator 613 to a Y-coordinate counter 620, the result of counting thereof being applied to a D-A converter 623 via an adder 621. The D-A converter 623 produces an analogue signal proportional to the content of the Y-coordinate counter 620. The analogue signal thus produced is applied to the vertical deflection coil of the photoelectric converter via a deflection amplifier 624. Consequently, the photoelectron image of the photoelectric converter is moved to the upper as shown in FIG. 7D. When the photoelectron image reaches the upper end the upper end detector 62 connected to the vertical mask register 59 generates an output which is applied to the reset terminal R of the second flip-flop circuit 618 shown in FIG. 8. When the flip-flop circuit 618 resets, the gate circuit 619 is desenabled to terminate the shifting operation. As a result of this shifting operation, the four digits in the field of view are moved toward the left upper side of the field so that the digit 2 to be detected and isolated will be brought to the left upper corner of the field of view as shown in FIG. 7F.

Then the projection signals produced by the vertical and horizontal mask registers 59 and 60 are eliminated by connector circuits 64 and 65 except the projection signal of the digit 2 which is to be detected and isolated. Although there are many types of the connector circuits available in this invention, one example thereof is illustrated in FIG. 9. In this figure numeral 60 indicates the horizontal register and the 1 outputs from flip-flop circuits 60.sub.1 to 60.sub.5 of respective orders are applied to one input terminals of AND circuits 66.sub.1 to 66.sub.5, respectively. The output from each AND circuit is applied to the input of the succeeding AND circuit and to the set terminals of five flip-flop circuits 67.sub.1 through 67.sub.5 constituting a register 67. A 1 signal from terminal 68 is always applied to the other input terminal of the leftmost AND circuit 66.sub.1.

In the operation of this connector circuit, when all flip-flop circuits 60.sub.1 through 60.sub.5 of the register 60 are in the 1 state, all flip-flop circuits 67.sub.1 through 67.sub.5 of the register 67 are also set to 1 state. When any one of the flip-flop circuits 60.sub.1 through 60.sub.5, for example 60.sub.3 is in the 0 state two flip-flop circuits 67.sub.1 and 67.sub.2 of the register 67 are caused to assume 1 state, but the remaining flip-flop circuits of this register 67 will not be set thus continuing their 0 state. Where the vertical register 59 is used instead of the horizontal register 60, the vertical connector circuit 64 is used.

By the use of these connector circuits, it is possible to take out from the projection signal shown in FIG. 7D two projection signals alone which are to be detected and isolated and apply them to the registers of the connector circuits 64 and 65, respectively.

The outputs from the vertical connector circuit 64 are applied to a height measuring circuit 69 to measure the height of the digit 2 being isolated. More particularly, the height measuring circuit 69 operates to count the number of 1 signals contained in the outputs from the vertical connector circuit 64. The height measuring circuit 69 may be constituted by a decoder, for example. The height signal produced by the height measuring circuit 69 is applied to the focusing control circuit 70 and to the deflection control circuit 61 of the photoelectric converter 51. In response to the height signal the focusing control circuit 70 operates to determine the current value necessary to cause the digit 2 being identified to have the desired size, and the current of the selected value is applied to the focusing device of the photoelectric converter 50 so as to enlarge the image. The deflection control circuit 61 functions to control the deflection device such that the digit 2 is deflected to the left upper corner of the field when the image is enlarged.

More particularly, the deflection quantities .alpha.X and .alpha.Y of the photoelectron image under these conditions are determined in the following manner. As shown in FIG. 7F, the enlarged letter has a predetermined normalized size. Assume now that the enlarged letter has a height Y.sub.0 and a width X.sub.0. The height y of the letter before enlargement is measured by the height measuring circuit 69 shown in FIG. 5. The width x is not required to be measured provided that the ratio of the height to the width is maintained constant. Where digit 2 is enlarged from the size shown in FIG. 7E to that shown in FIG. 7F, the quantities of the deflection .DELTA.X and .DELTA.Y required to cause the enlarged digit 2 to engage the left upper corner of the field of view as shown in FIG. 7F are expressed as follows.

.DELTA.Y = (Y.sub.0 /y), .DELTA.X = (X.sub.0 /Y.sub.0) .sup.. .DELTA.Y

Thus, the magnifying power is determined by obtaining a ratio Y.sub.0 /Y between the output y of the height measuring circuit 69 and the height Y.sub.0 after enlargement, thereby determining the currents supplied to the first and second focusing coils 15 and 16 of the photoelectric converter. The output y from the height measuring circuit 69 is applied to the operation circuit 625 shown in FIG. 8 which is constructed to aid .DELTA.X and .DELTA.Y to produce -.DELTA.X and -.DELTA.Y on the output terminals. These outputs are applied to adders 615 and 621 respectively, and are substracted from the contents of X-counter 614 and Y-counter 620. The outputs of adders 615 and 621 are again converted into analogue signals by the D-A converters 616 and 623 and the resulting analogue signals are applied to the deflection coils.

Above described operations of normalizing the size and position of the pattern to be identified are performed by the optical means. Upon completion of the normalizing operation of the digit 2 to be isolated, the isolating operation of this digit 2 is performed by isolating circuit 71. As shown in FIG. 10, the isolating circuit 71 is constituted by a pluality of AND gate circuits 72 provided for respective output conductors 52.sub.3 of the photoelectric converter 51 which have passed through the matrix circuit 54. In FIG. 10, a plurality of points 52 which are arranged in a matrix correspond to respective output conductors generally shown by a numeral 52.sub.3 in FIG. 5, and these points are connected to one input terminals of three input AND gate circuits 72 The input terminals of the AND gate circuits 72 belonging to the rows of the matrix are commonly connected to the output conductors 73 of the vertical connector circuit 64 as shown in FIG. 7F, whereas the lower input terminals of the AND gate circuits belonging to the columns of the matrix are commonly connected to respective output conductors 74 of the horizontal connector circuit 65 also shown in FIG. 7F. The outputs 75 of respective AND gate circuits 72 are connected to the identifying circuit shown in FIG. 5.

If both output conductors 73 and 74 of the vertical and horizontal connector circuits 64 and 65 of the isolating circuit 71 are applied with the 1 signal at the same time, AND gate circuits 72 are enabled so that the output from the photoelectric converter can pass through the AND gate circuits but signals other than this output can not pass through the AND gate circuits. Accordingly, only the image signals corresponding to the digit 2 appear on the output conductors 52.sub.4 of the isorating circuit 71.

The image signals of digit 2 selected and isolated in this manner are applied to a pattern identifying circuit 76 thereby identifying the digit 2. Many types of the identifying circuits have already been proposed and any one of them can be used in this invention. Briefly stated, the identifying circuit 76 is constructed such that when it completes the identification on operation of a given digit, it provides a termination signal to deflection control circuit 61 as above described to prepare for the reading of the next digit or letter.

Although in this embodiment, a particular pattern to be isolated is shifted to the left upper corner of the field of view as shown in FIG. 7F, it is also possible to shift the isolated pattern to the center of the field of view by taking out the input signals to the upper end detector and left end detector from suitable positions of the horizontal and vertical registers and by connecting the connector circuits on both sides of such positions. Moreover, it should be understood that the deflection control circuit shown in FIGS. 3 and 5 may be comprised by a well known circuit utilized in a flying spot scanner or the like. Similarly, the focusing control circuit may be constituted by a digital counter, a D-A converter, a current amplifier or the like.

Thus, it will be clear that the pattern idenfifying apparatus provided an ability just like that of human eyes.

Since the output from the photoelectric converter consists of two dimensional signal it is easy to perform spacial processing necessary to identify patterns, thus improving the ability of the pattern identifying apparatus.

Claims

What we claim is:

1. Apparatus for processing patterns including a photoelectric converter which comprises a photoelectric surface on which a photoinput image of a pattern to be identified is to be projected, focusing means for focusing photoelectrons emitted by said photoelectric surface in response to said photoinput image to form a photoelectron image on a focal plane, means to enlarge or reduce said photoelectron image, deflecting means for moving the position of said photoelectron image in said focal plane, an array of a plurality of electron beam detecting elements which are arranged in a plane near said focal plane, each electron beam detecting element generating a current proportional to the quantity of the electron beam impinging thereon, an evacuated envelope containing said elements of said photoelectric converter and means for deriving out in parallel outputs from said electron beam detecting elements.

2. A pattern processing apparatus according to claim 1 wherein said focusing means comprises a first focusing coil disposed near said photoelectric surface and a second focusing coil disposed near said focal plane, and said means for enlarging or reducing the photoelectron image comprises means for varying the ratio between currents supplied to said first and second focusing coils so as to enlarge or reduce said photoelectron image.

3. A pattern processing apparatus according to claim 1 wherein said electron beam detecting elements comprise a plurality of semiconductor detecting elements.

4. e pattern processing apparatus according to claim 3 wherein said semiconductor detecting elements comprise a p-type semiconductor substrate, a plurality of discrete n-type regions formed on one surface of said semiconductor substrate, a plurality of discrete metal electrodes formed in respective n-type regions and output conductors connected to respective electrodes.

5. A pattern processing apparatus comprising a photoelectric converter including a photoelectric surface on which a photoinput image is to be projected, focusing means for focusing photoelectrons emitted from said photoelectric surface in response to said photoinput image to form a photoelectron image on a focal plane, means for enlarging or reducing said photoelectron image, deflecting means for moving the position of said photoelectron image in said focal plane, an array of a plurality of electron beam detecting means which are arranged in a plane near said focal plane, each electron beam detecting element generating a current proportional to the quantity of the electron beam impinging thereon, an evacuated envelope containing said elements of said photoelectric converter and a plurality of output conductors respectively connected to said electron beam detecting elements and are led out to the outside of said envelope; means for detecting a characteristic portion of the picture image signal derived out through said output conductors; means responsive to the output of said characteristic portion detecting means for driving said means for enlarging or reducing said photoelectron image; and means for controlling said deflecting means so as to maintain said detected characteristic portion at a predetermined position of the field of view of said photoelectric converter which is formed by said array of said electron beam detecting element when enlarging or reducing said photoelectron image.

6. A pattern processing apparatus according to claim 5 wherein said means for detecting the characteristic portion of said picture image signal comprises means for detecting the maximum value of the picture image signal level.

7. A pattern processing apparatus according to claim 6 which further comprises means for driving said means for enlarging or reducing said photoelectron image when the maximum value of said picture image signal exceeds a predetermined threshold value and for controlling said deflection means so as to maintain the portion of said picture image signal manifesting the maximum value in the field of view of said photoelectric converter.

8. A pattern processing apparatus according to claim 5 wherein said focusing means comprises a first focusing coil disposed near said photoelectric surface and a second focusing coil disposed near said focal plane, said means for enlarging or reducing the photoelectron image comprises means for varying the ratio between the currents supplied to said first and second focusing coils and said array of the electron beam detecting elements comprises a p-type silicon semiconductor substrate, a plurality of descrete n-type regions formed on one surface of said substrate, a plurality of metal electrodes formed in the respective n-type regions and output conductors connected to respective metal electrodes.

9. A pattern processing apparatus comprising a photoelectric converter including a photoelectric surface on which a photoinput image of a pattern to be identified is to be projected, focusing means for focusing the photoelectrons emitted from said photoelectric surface in response to said photoinput image to form a photoelectron image on a focal plane, detecting means for moving the position of said photoelectron image in said focal plane, an array of a plurality of electron beam detecting elements disposed in a plane close to said focal plane, each electron beam detecting element generating current acting as a picture image signal and proportional to the quantity of said electron beam impinging thereon, and an evacuated envelope containing said elements of said photoelectric converter; a plurality of output conductors respectively connected to said detecting elements; means for detecting the output conductor carrying said picture image signal to control said deflection means so as to move said photoelectron image in said focal plane; and means for detecting the output conductor carrying the picture image signal of only a pattern to be identified.

10. A pattern processing apparatus according to claim 9 wherein said means for detecting the output conductor carrying said picture image signal comprises a mask shaping circuit including means for computing a logical sum of the signals for respective rows and columns of a matrix comprised by said output conductors, and vertical and horizontal mask registers respectively responsive to the logical sum of the rows of said matrix and the logical sum of the columns of said matrix for storing the projection signal in the vertical and horizontal directions respectively, wherein said means for moving the position of said photoelectron image in said focal plane comprises means for supplying the signals stored in said vertical and horizontal mask registers of said mask shaping circuit to said deflecting means of said photoelectric converter as the control signals, wherein said means for detecting the output conductors carrying only the picture image signal of a pattern to be identified comprises a plurality of gate circuits respectively associated with said output conductors, and means for controlling said gate circuits in accordance with the output signals from said vertical and horizontal mask registers.

11. A pattern processing apparatus according to claim 9 wherein said focusing means comprises a first focusing coil disposed near said photoelectric surface and a second focusing coil disposed near said focal plane, said means for enlarging and reducing said photoelectron image comprises means for varying the ratio between the currents supplied to said first and second focusing coils, and said array of said electron beam detecting elements comprises a p-type silicon semiconductor substrate, a plurality of discrete n-type regions formed on one surface of said semiconductor substrate, metal electrodes respectively formed in said n-type regions and a plurality of output conductors respectively connected to said metal electrodes.

12. A pattern processing apparatus comprising a photoelectric surface on which a photoinput image of a pattern to be identified is to be projected, focusing means for collecting the photoelectrons emitted from said photoelectric surface in response to said photoinput image projected thereon to form a photoelectron image on a focal plane, means for enlarging or reducing said photoelectron image, deflecting means for moving the position of said photoelectron image in said focal plane, an array of a plurality of electron beam detecting elements arranged in a plane near said focal plane, each detecting element generating a current acting as a picture image signal and proportional to the quantity of the electron beam impinging thereon, and an evacuated envelope containing above described various elements of said photoelectric converter; a plurality of output conductors respectively connected to said electron beam detecting elements; a mask shaping circuit including vertical and horizontal mask registers connected to detect the presence or absence of the signals on said output conductors for storing the projection signals in the vertical and horizontal directions of the detected picture image signal; and a circuit for controlling said means for enlarging or reducing said photoelectron image and said deflecting means in accordance with the contents of said vertical and horizontal mask registers of said mask shaping circuit.

13. A pattern processing apparatus according to claim 12 wherein said mask shaping circuit comprises means to compute logical sums of signals of respective rows and columns of said matrix comprised by said output conductors, and means for supplying said logical sums to said vertical and horizontal mask registers respectively.

14. A pattern processing apparatus according to claim 12 wherein said focusing means comprises a first focusing coil disposed near said photoelectric plane and a second focusing coil disposed near said focal plane, said means for enlarging and reducing the photoelectron image comprises means for controlling the ratio between the currents supplied to said first and second focusing coils, and said array of said electron beam detecting elements comprises a p-type silicon semiconductor substrate, a plurality of discrete n-type regions formed on one surface of said semiconductor substrate, a plurality of metal electrodes formed in the respective n-type regions and output conductors connected to respective metal electrodes.