GB2176038A - Coin discriminator - Google Patents

Abstract

An apparatus for discriminating between coins of different value by determining their sizes. The coin discriminator includes a two-dimensional, coin-measuring array of optical sensors arranged to establish predetermined coin-measuring boundaries, a channel for guiding coins past the coin-measuring array, and circuitry for determining when a coin has been guided by the channel to a trigger point where its diameter can be measured by the sensor array. When a coin approaches the trigger point, the circuitry activates the sensor array. Then, when the coin reaches the trigger point, the circuitry triggers a measurement circuit which identifies the size-and value-of the coin by sampling the activated sensor array to determine the furthest measurement boundary from the trigger point that is crossed by the coin. <IMAGE>

Description

SPECIFICATION Coin discriminator Background of the invention The disclosed coin discriminator is in the field of apparatus which measure coins or tokens and use the measurements to identify their denominations or equivalent values.

As is known, fare- or rate-collecting systems employ apparatus for accepting payment in the form of coins or tokens. In such apparatus, the value of deposited coins is determined by assaying predetermined coin characteristics. For example, the weight or mass of a coin gives a direct indication of its denomination.

More commonly, in such apparatus the value of a coin is determined by measurement of one or more coin dimensions such as chord, radius, diameter, circumference, or thickness. In the field of apparatus that measure coin dimensions such as diameter or radius, it is known to move a coin to be measured past an array of sensors in which each sensor element has a known distance from a pre-established reference or measuring line. In most such apparatus, the reference line is typically colinear with the edge of a coin guide channel and consists of a channel surface (usually the edge of the channel) that supports the edge of a coin as it moves past the array of sensors. Most frequently, the channel surface has a vertical drop in order to accelerate the coin from a point where it enters the apparatus to a point where deposited coins are collected.

The measurement in such devices is dependent upon a coin's remaining on the reference surface as it travels in order to register it accurately with the coin-measuring array. If the coin bounces from the reference surface when being measured by the array, its apparent size will differ from its actual size and a false indication of its value will be given. Such bouncing is difficult to prevent in apparatus that move coins at a high speed.

It is also known to use a coin-measuring sensor in combination with a sensor positioned with respect to the array. In this arrangement, the position of the sensor defines an imaginary reference point in a coin channel rather than at its edge. The sensor array is so constructed as to be indifferent to the precise location of a coin in relation to the edge of the channel. This frees the measurement device from sensitivity to a coin bouncing off the sides of the channel. However, such devices require the measurement of conjoint obscuration by a coin of the reference. and successive array sensors to identify large-denomination coins. This measuring arrangement can result in a continuously changing coin identification signal that correctly identifies a measured coin only with the last of a series of coin identification signals produced by a coin being measured.This corresponds roughly to opening the shutter of a camera to obtain the photograph of a moving object and leaving the shutter open until the object is fully within the camera's field of view, after which the shutter is closed. The penalty of such a measurement technique is that provision must be made to determine when the correct coin-identifying signal is provided. In the existing device, this results in the requirement for extra circuitry to identify the last in a sequence of coin identifying signals. Moreover, it requires that the sensor array be energized during the whole period when a coin is moving past it, resulting in unnecessary consumption of power to keep the array active and, in the case of optical sensors, reduction in the useful lifetime of light sources that illuminate the array.

A significant reduction in circuitry and energy necessary to operate such an array would result in the array were operated in a "snap-shot" fashion, in which the array would be momentarily activated to measure a coin upon the coin reaching a predetermined reference position. The momentary activation would result in the production by the array, for coins of all sizes, of a single signal indicative of a coin dimension that is directly convertible to the corresponding of a coin.

Summary of the invention The coin discriminator of the invention includes a coin-measuring array of optical sensors that is efficiently operated to extend the lifetime of and reduce the total power consumed by the array when operated to identify coins. Efficient operation is provided by a shutter-like circuit arrangement that determines when a coin moving in a coin chute nears a predetermined trigger boundary in its path of travel, activates the array, and then performs the measurement when the coih reaches the boundary. Upon completion of the measurement, the arrangement deactivates the array until another coin nears the trigger boundary.

The coin discriminator of the invention includes a plurality of optical detectors arranged in a predetermined two-dimensional array and a plurality of light sources that are selectively activated coins to move from a coin source to a coin collector on a path of travel that passes between the array detectors and the light sources and past a trigger boundary that is offset from the array along the direction of travel of the coin.

The shutter-like circuit arrangement includes an activation circuit that activates the light sources to illuminate the array detectors when a coin in the channel has moved between the array detectors and the light sources and neared the trigger boundary in the channel. A trigger circuit responds to the activation circuit when the light sources have been activated and one edge of the coin reaches the trigger boundary by triggering identification circuitry which identifies the coin by determining which of the array detectors are blocked by another, diametrically-opposed edge of the coin when the one edge is at the trigger boundary.

Measurement of a coin only when it reaches the trigger boundary permits the identifying circuitry to produce a single coin-identifying signal for each coin measured.

Further circuitry is provided for turning off the light sources when the determination of coin value is made.

The primary objective of the present invention is therefore to provide an apparatus for determining the value of a coin by means of an optical sensor array that is operated in a shutter-like fashion to make a single coin-identifying measurement for each coin to be identified.

Afurther objective of the present invention is to provide an improved coin identification apparatus.

One major advantage of the invention is the reduction in total power consumed by a coin-measuring optical sensor array and the concomitant extension of the lifetime of the array sensors.

Other dbjectives and attendant advantages of the present invention will become more apparent when the following detailed description of the invention is read in conjunction with the below-described drawings.

Brief description of the drawings Figure 1 is a perspective view of a coin channel incorporating the coin discriminator of the invention.

Figure 2 is a sectional view of the Figure 1 channel taken along the lines 2-2.

Figure 3 is a plan view that shows construction details of an electro-optical device incorporated into the coin channel segment illustrated in Figure 1.

Figure 4 is a plan view of the eiectro-optical device array used in the coin discriminator of the invention showing incorporation of an isosceles pattern of devices.

Figure 5 is an enlarged view of the detector array of Figure 4 showing the relative positioning of the array elements to establish coin-measuring boundaries for different denominations of coins.

Figure 6 is a schematic diagram including a representational layout and electrical interconnections of electro-optical elements used to implement the array of Figures 4 and 5.

Figure 7 is a block diagram illustrating electronic circuitry used to control and interpret the operation of the electro-optical elements of Figure 6.

Figure 8 is a timing diagram illustrating certain operations of the Figure 7 circuit.

Detailed description of the preferred embodiment With reference now to Figure 1, there is illustrated a segment 10 of a coin chute having a coin channel 11 of rectangular cross section through which coins such as the coin 12 travel in a generally vertical direction. Coins may be placed into the chute 10 by conventional coin-sequencing apparatus such as may be found in a farebox on a public transportation vehicle. Coins fall through the chute from the coin sequencerto a vault or cashboxwith which the coin chute 10-communicates.

As shown in Figure 2, a cross section of the chute segment 10 taken along lines 2-2 in Figure 1, the chute is constructed from a pair of opposing chute walls 14 and 15 between which are sandwiched a pair of opposing chute side stops 16 and 17.

An array of electro-optical detectors is disposed on a detector carrier 18 that is fastened to the inner surface of the chute wall 14. The detectors on the carrier 18 are isolated from physical contact with a coin by a transparent overlay 19. A plurality of electro-optical light sources is disposed on a source. carrier board 20 disposed in opposing alignment with the board 18 on the inner surface of the chute wall 15.

The light sources on the carrier 20 are also protected from physical contact for the coin in the channel 11 by a transparent overlay 21. Electrical connection is provided to the electro-optical elements on the carriers 18 and 20 through a conventional electrical ribbon cable 21.

Figures 3 and 4 show the general construction of the carriers 18 and 20 and illustrate the specific twodimensional arrangement of the opposing electro-optical sources and detectors. It is to be understood that the geometrical arrangement illustrated in- Figures 3 and 4 is the same for the light sources on the carrier 20 as for the detectors on the carrier 18.

As shown in Figures 3 and 4, a first plurality of electro-optical elements on the carrier board 18 is arranged into a specific two-dimensional coin-measuring array 30 that has disposed beneath it a vertical sequence 31 of electro-optical elements. The overlay 19 can comprise a conventional opaque plastic having an array of holes or apertures 23 that duplicates the element array. When the overlay 19 is properly aligned with the carrier board 18, the apertures 23 align with the electro-optical elements on the carrier 18 to provide an unobstructed field of view from each element into the chute channel 11. The electrooptical source carrier 20 has an array of light-emitting elements that is identical to the array of detectors illustrated in Figure 4. Similarly, the overlay 21 is identical with the overlay 19 so that when the carriers 18 and 20 are brought into opposing alignment, each of the electro-optical sources on the carrier 20 is aligned to illuminate a corresponding electro-optical detector on the carrier 18. Each aligned source-detector pair is effectively an optical presence sensor that senses the presence of a coin interposed between the elements, which blocks the detector from being illuminated.

As can be seen in Figure 4, the coin-measuring array 30 has a shape which can be characterized as being generally isosceles with two non-parallel legs of equal length and a horizontal base. Although the coin-measuring array 30 is shown in Figure 4 to have the general shape of an isosceles triangle, it should be evident that it could also have the shape of an isosceles trapezoid, with the shorter of the two parallel sides being above the longer and the longer being the base. In either case, the base of the isosceles pattern is substantially perpendicular to the path of movement followed by coins in the chute 10.

The row 32 of elements disposed beneath the array 30 defines a coin-edge trigger (CET) boundary which, together with respective coin-measuring boundaries defined by the elements in the coin-measuring array 30, establishes respective coin-measurement dimensions. Each measurement dimension corresponds substantially to the diameter of a known coin or token.

In the preferred embodiment, the elements 32a-32f form the CET boundary 32. The elements 38a-38c form a dime boundary 38 that is offset from the CET boundary 32 by a distance slight less than the diameter of a dime. Similarly, the elements 40a-40b form a penny boundary 40 that is offset from the CET boundary 32 by a distance slightly less than the diameter of a U.S. cent. Therefore, a dime with one edge touching the CET boundary 32 will extend into the two-dimensional area between the dime boundary 38 and the penny boundary 40. Similarly, the detectors 42a-42c establish a boundary 42 for a U.S.

nickel, the elements 44a and 44b a boundary 44 for -a token T, of predetermined size and value, the elements 46a and 46b a U.S. quarter boundary 46, the element 48a a U.S. dollar coin boundary 48, the element 50a a boundary 50 for a second token T2 of predetermined size and value, and the element 52a a boundary 52 for a U.S. half dollar (50 cent) piece. The distance between the CET boundary 32 and the boundaries 38-52 are given together with the diameters of the respective corresponding coins measured by the boundaries.

TABLE 1 Coin measurement boundary Distance to CET boundary Distance To Trigger Coin Coin Boundary Boundary Measured Diameter 38 .655 U.S. Dime (10 cents) .705 40 .705 U.S. Penny (1 cent) .750 42 .760 U.S. Nickel (5 cents) .835 44 .845 Token T1 46 .910 U.S. Quarter (25 cents) .955 48 .975 U.S. Dollar ($1) 1.043 50 1.06 Token2 1.125 52 1.14 U.S. Half Dollar (50 cents) 1.205 The vertically-arranged sensors 31a and 31b are spaced an equal distance from a point P between them that is 0.315 inches from' the CET boundary 32. The width (Win Figure 5) of the channel 11 is 1.25 inches and the center line 53 of the array 30 (which extends vertically from the element 52a down to the element 38b), the elements 31 a and 31 b, and the center element 32c of the CET boundary 32 are centered in the channel 11.The element 38a is spaced from the element 38b at such a distance that when a U.S. dime is positioned with its periphery touching the channel spacer 16, it will block the element 38a, the elements 31a and 31b, and one of the elements forming the CET boundary 32.

Similarly, spacing of the elements 40a-40d, 42a-42c, 44a and 44b, and 46a and 46b are such that the respective coins or tokens for which they define measuring boundaries will cover at least one respective element in the measuring boundary, the elements 31a and 31b, and at least one of the elements in the reference boundary 32 no matter where the coin is laterally located with respect to the center line 53 of the coin-measurement array.

It should be evident that the diameter of the U.S. dollar coin, the token T2, and the U.S. half dollar are such that they will cover the elements 48, 50, or 52, respectively, together with the elements 31a and 31b, and at least one element of the reference boundary 32 no matter what their position with respect to the center line of the array 30.

The Figure 5 array permits identification of a coin positioned with an edge touching the CET boundary row 32 and a second, diametrically-opposed edge extending in the channel between the opposing light source and detector arrays. The coin's diameter and denomination can be determined by determining the position of the second edge with respect to the array. The second edge's position is indicated by the coin-measuring boundary furthest from the CET boundary having at least one light detector blocked by the coin. The second edge is adjacent this boundary. Since this furthest blocked boundary is associated with the diameter and denomination of the blocking coin, the identification follows.

The positioning of the carriers 18 and 20 in opposing alignment across the coin channel 11 results in a plurality of optical sensor pairs of associated, aligned light-emitting and light-detecting elements shown in Figure 6. In Figure 6, electro-optical emitters comprise conventional light-emitting diodes (LED's), each denoted by the reference letter D and a respective numerical subscript. The plurality of electro-optical detectors: on the carrier 18 comprise phototransistors, each indicated by the reference ietter Q with a respective numerical subscript. An identical numerical subscript in Figure 6 indicates associated alignment between an LED and a phototransistor. Moreover, the numerical subscripts correlate to the element positions illustrated in Figure 5, and therefore are indicative of an element's location on its respective carrier.For example, the LED D,, and the phototransistor Q40a both have locations on their respective carriers corresponding to element 40a in Figure 5, and, since the carriers 18 and 20 are aligned, these two elements are in opposing alignment across the channel 11.

Each LED on the carrier 20 is connected in series with another one of the LED's to form an LED pair.

The LED pair D31, and D31b are forward biased by connection between a positive diode voltage V1 and ground. In all of the other diode pairs, the anode of one of the pair is connected to the positive voltage V1, while the cathode of the other of the pair is connected to a signal line labelled LED STROBE.

On the carrier 18, the phototransistors corresponding to elements 48a-52a are each connected between ground and a signal line corresponding to the denomination of the coin or token in whose measuring boundary the respective element is contained. The remaining phototransistors are connected in series between ground and respective signal lines corresponding to the boundaries defined by the transistors.

Thus, -for example, the transistors 0,, and Q44b are connected in series between ground and a signal line labelled T to indicate correspondence with the measuring boundary 44 for the T, token. In addition, the transistors Q31, and Qaib are linked in series between ground and a signal line labelled ACTIVATE, while the transistors Qs2,Q, are series-connected between ground and a signal line CET.

In operation, a coin falling downward in the chute 11 will pass between the LED's and phototransistors aligned in the opposing patterns corresponding to the pattern 30 of Figures 4 and 5. Next, the leading edge of the coin will pass between the LED's and phototransistors corresponding to elements 31a and 31b in Figures 4 and 5. Finally, the leading edge of the coin will reach the CET boundary 32.

As explained below, the element arrays illustrated in Figure 6 are controlled and operated to sense the presence of coin passing between the elements aligned in the coin-measuring arrays. The presence of a coin is detected when the edge of the coin passes between the activated LED pair Dsi, and D3,b and- the series-connected phototransistor pair Q31, and 031b When the leading edge of the coin blocks the illumination of either of the transistors 0,,, or Q3lb, the transistor is turned off, which raises the voltage on the READY signal line. When the voltage rises on the READY signal line, the LED STROBE signal is enabled which forward biases all of the other LED's on the carrier 20.The LED STROBE signal is provided quickly enough to energize the CET boundary LED's before the leading edge of the coin reaches the CET boundary. Then, when the coin falls far enough for its leading edge to block light transmission from one of the LED's D,,,-D,,, to at least one of the transistors Q32,-Q32,, voltage rises on the CET boundary signal lead.

When this occurs, the voltages on the 10 cent through the 50 cent signal lines are simultaneously sampled. The outcome of this simultaneous sampling is converted into a coin identification signal.

Circuitry for operating the LED and phototransistor arrays of Figure- 6 is illustrated in Figure 7. Figure 8 illustrates the timing relationship of the operations of the circuit illustrated in Figure 7. The circuitry of Figure 7 includes a plurality of conventional comparator circuits 60a-j connected to receive the phototran- - sistor- signal leads of Figure 6. Each of the comparators compares the voltage on its respective signal lead against a comparison voltage V,; when the signal lead voltage exceeds V, (at least one phototransistor blocked and not conducting) the comparator output will rise; when the signal line voltage is less than V, (all phototransistors illuminated and, therefore, conducting), the comparator output will fall.

Thus, when the edge of a coin passes between the READY LED's and phototransistors, at least one phototransistor will shut off, raising the voltage on the READY signal line, which will cause the output of comparaor 60, connected to the READY signal line, to rise. The rising edge of this comparator output will be inverted and input to the trigger port of a conventional negative-edge triggered, resettable one-shot timer 66. Triggering the timer 66 will cause its output to transition positively at edge 67. The output of the timer 66 corresponds to the ACTIVATE signal waveform of Figure 8. The positive level of the Timer 66 signal is converted by a conventional transistor buffer circuit 72 to the LED STROBE signal, which transitions in a negative direction at 73 in response to the positive transition 67 of the ACTIVATE signal.

The negative transition of the LED STROBE signal is connected to the correspondingly- abelled signal line on the carrier 20 of Figure 6, causing the activation of all of the other LED's on the carrier.

At the same time that the ACTIVATE signal enables the LED STROBE signal, it removes the reset on another one-shot timer 75 to prepare itfor performing a "snap-shot" measurement of the coins the chute between the carriers 18 and 20. This places the coin discriminator of the invention in a waiting state and readies it to respond to the sensing of the leading edge of the coin by the CET phototransistors Q32'-Q32,.

At the instant when the leading edge of the falling coin blocks illumination of one of the phototransistors Q32,-Q32,, the comparator 60b connected to the CET signal line converts the signal line voltage to a CET signal. The positive transition 77 of the CET voltage signal indicates the blockage of one of the CET phototransistors and is inverted and fed to the trigger input of the one-shot timer 75. When the timer 75 is triggered, its rising output is inverted to produce the inverted logic level signal COIN PRESENT.

The negative transition 79 of the COIN PRESENT signal causes the outputs of the latch circuit 62 to latch to the current state of their associated inputs. The inputs to the latch 62 are the signal lines connected to the coin-measurement array phototransistors. At the moment when the leading edge of a coin blocks a phototransistor in the CET array, its diametrically-opposed trailing edge will block at least one of the phototransistors that define the measurement boundary of that coin. Of course, other phototransistors beneath the measurement boundary for that particular coin will also be blocked. Further, none of the phototransistors defining the measurement boundaries above the coin will be blocked. Therefore, the inputs to the latch 62 from the coin measurement boundary signal lines will indicate the highest coinmeasuring boundary blocked by the coin.The highest blocked boundary will cause a corresponding high output from its interface comparator, which operates effectively as the most significant bit (MSB) of the latched signals. Once latched, the measurement boundary signals function essentially as an 8-bit address signal provided to a programmable read only memory (PROM) 82. The memory storage map of the PROM 82 is structured so that a 4-bit COIN CODE signal is output that uniquely identifies the coin associated with the MSB of the input address.

Thus, for example, if a U.S. quarter were measured, it would fall through the coin chute and pass between the carrier boards 18 and 20, with its leading edge eventually activating the LED STROBE and COIN PRESENT signals as described above. When the COIN PRESENT signal falls, the condition of the coin measurement array phototransistors will be latched by the latch circuit 62. Since a quarter is being measured, the highest-magnitude bit of the latched address will correspond to the high output from the buffer comparator connected to the 25 cent signal line. The address bit corresponding to the $1, T2, and 50 cent signal lines will be reset (low). In response to the latched signal, the PROM 82 will produce a 4bit COIN CODE signal stored at an address whose MSB corresponds to the 25 cent signal line and identifying the quarter.

The coin discriminator of the invention provides as output signals the COIN CODE and COIN PRESENT signals. This permits processing circuitry, not shown, to respond to the COIN PRESENT signal as an interrupt indicating the presence of a coin and the COIN CODE signals as data signals that identify the coin.

The COIN PRESENT signal is also inverted and fed to a negative-edge-triggered, one-shot timer 81, so that when the timer 75 times out and causes the COIN PRESENT signal to transition positively at 80, the timer 81 is triggered. The output of the timer 81 constitutes an OFF signal having a positive transition 83 stimulated by the positive transition 80 of the COIN PRESENT signal. The OFF signal is inverted and fed to the reset input of the timer 66. The OFF signal resets the timer and causes the LED STROBE signal to transition negatively at 85. This turns off all of the LED's on the carrier 20 save the ACTIVATE LED's.

To complete the operational cycle of the coin discriminator, the coin which has been measured continues to fall past the ACTIVATE LED's until its trailing edge moves past them, thereby permitting them to once more illuminate the ACTIVATE phototransistors, which causes the voltage on the ACTIVATE signal line to transition toward ground.

It should be evident that the total timing delay imposed by the timers 75 and 81 should be less than the time it takes for the smallest coin to pass the ACTIVATE elements. When this condition is fulfilled, the coin discriminator will be ready to immediately measure another coin.

It should be evident that many modifications or variations of the present invention are possible in light of the description of the preferred embodiment. It is therefore to be understood that, within the scope of the appended claims, the coin discriminator of the invention may be practiced otherwise than as specifically described.

Claims (22)

1. An apparatus for identifying coins, tokens, or the like, comprising: a channel for guiding a coin from a coin source to a coin collector on a path of travel; plural optical sensor means, arranged adjacent said channel in a predetermined two-dimensional coinmeasuring array, and responsive to a strobe signal for being activated for a predetermined period of time to indicate the location of a first portion of the periphery of an adjacent coin with respect to a predetermined trigger location in said path of travel; activation means responsive to a second periphery portion of said coin that is diametrically opposed to said first portion for activating said optical sensor means when said second periphery portion is a predetermined distance from said trigger location and said first periphery portion is adjacent said array;; sampling means for, substantially simultaneously with said second periphery portion reaching said trigger location, sampling said sensor means to determine the location of said first periphery portion; and means for, based upon said determination, identifying said coin.

2. The apparatus of Claim 1 wherein said trigger location is defined by an elongate trigger row of optical sensors that is substantially perpendicular to said path of travel.

3. The apparatus of Claim 2 wherein said coin-measuring array includes at least two measuring rows of optical sensors, each substantially parallel to said trigger row and displaced from said trigger row by a respective distance corresponding substantially to the diameter of a certain coin.

4. The apparatus of Claim 2 wherein said coin-measuring array includes at least two individual optical sensors, each displaced from said trigger array by a respective distance corresponding substantially to the diameter of a certain coin.

5. The apparatus of Claim 2 wherein said coin-measuring array has a substantially isosceles shape with a pair of non-parallel sides and a base substantially parallel to said trigger array.

6. The apparatus of Claim 5 wherein said sensor means are arranged into a plurality of measuring groups, each defining a respective coin-measuring boundary that is displaced from said trigger row by-a respective distance corresponding to the diameter of a certain coin.

7. The apparatus of Claim- 6 wherein said sampling means responds to said second periphery portion reaching said trigger location by sampling the sensor means in each measuring group and providing boundary signals representative of the coin-measuring boundaries between said first and second periphery portions that is closest to said first periphery portion.

8. The apparatus of Claim 7 wherein said identifying means includes a programmable storage device for storing signals indicative of specific coins or tokens at respective storage locations addressed by address signals including said boundary signals produced by said sampling means.

9. The apparatus of Claim 2 further including means in said circuit means for deactivating said sensor means a predetermined amount of time after said activation.

10. A method for identifying coins, comprising the steps of: moving a coin on a path of travel past a plurality of sensors that can be activated to sense the location of a first edge of said moving coin with respect to a trigger boundary in said path of travel; activating said sensors when a second edge of said moving coin, diametrically opposite said first edge, is a predetermined distance from said trigger boundary; after said activation, sensing with said sensors the location of said first edge with respect to said trigger boundary when said second edge reaches said trigger boundary; providing from said sensors a signal indicating said location; and converting said signal to a coin code signal indicating the denomination of said coin.

11. The method of Claim 10 wherein said coin has a denomination indicated by its diameter and said array includes a first sensor displaced from said trigger boundary by a distance greater than said diameter and a second sensor displaced from said trigger boundary by a distance less than said diameter and said step of sensing includes preventing with said first edge the operation of said second sensor.while permitting the operation of said first sensor.

12. The method of Claim 11 further including the step of deactivating said sensors after said step of providing.

13. An apparatus for identifying coins, comprising: chute means for moving coins serially on a defined path- of travel; a plurality of coin-measuring light detectors adjacent one side of said path of travel, at least one of said optical detectors displaced from a predetermined trigger boundary on said path of travel by a predetermined distance indicative of the diameter of a coin moving in said path of travel; light means adjacent another side of said path of travel opposite said optical detectors for -illuminating said optical detectors in response to a strobe signal; activation means for providing said strobe signal when one edge of a coin moving in said path of travel is a predetermined distance from said trigger boundary;; determining means connected to said light detectors for, when said light means are activated and one edge of a coin moving in said path of travel reaches said trigger boundary while a second, diametricallyopposed edge of said coin is between said light detectors and said light means, determining the diameter of said coin by which of said light detectors are blocked from illumination by said second edge of said coin; and identifying means for, based upon said diameter determination, providing a coin code signal identify ing said coin.

14. The apparatus of Claim 13 wherein said trigger boundary is defined by an elongate trigger row of optical sensors that is substantially perpendicular to said path of travel.

15. The apparatus of Claim 14 wherein said light detectors are arranged in a two-dimensional coinmeasuring array that includes at least two measuring rows of light detectors, each substantially parallel to said trigger row and displaced from said trigger row by-a respective distance corresponding substantially to the diameter of a certain coin.

16. The apparatus of Claim 14 wherein said coin-measuring array includes at least two-individual optical sensors, each displaced from said trigger array by a respective distance corresponding substantially to the diameter of a certain coin.

17. The apparatus of Claim 14 wherein said coin-measuring array has a substantially isosceles shape with a pair of non-parallel sides and a base substantially parallel to said trigger array.

18. The apparatus of Claim 17 wherein said light detectors are arranged into a plurality of measuring groups, each defining a respective coin-measuring boundary that is displaced from said trigger row by a respective distance corresponding to the diameter of a certain coin.

19. The apparatus of Claim 18 wherein said determining means respond to said first edge reaching said trigger boundary by sampling said light detector sampling groups and providing a boundary signal respresentative of which of the coin-measuring boundaries between said first and second coin edges is nearest said second edge.

20. The apparatus of Claim 19 wherein said identifying means includes a programmable storage device for storing signals indicative of specific coins or tokens at respective storage locations addressed by address signals including said boundary signals produced by said sampling means.

21. Apparatus for discriminating between coins of different value by determining their sizes comprising a two-dimensional coin-measuring array of optical sensors arranged to establish predetermined coinmeasuring boundaries, means for guiding coins past the coin-measuring array, means for actuating the sensor array as the coin approaches a trigger point where the coin can be measured by the sensor array, and means, when the coin reaches the trigger point, for identifying the coin by sampling the activated sensor array to determine the furthest measurement boundary from the trigger point that is crossed by the coin.

22. Apparatus for identifying coins substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.