JP3367730B2 - Adjustment mechanism of random pulse generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a random pulse generator for randomly generating pulses by counting radiation (α, β, γ rays) of decay particles randomly emitted from radioactive materials, and more particularly, to a random pulse generator. The present invention relates to an adjustment mechanism of a random pulse generator that adjusts a count value corresponding to probability.

[0002]

2. Description of the Related Art Conventionally, in pachinko machines and game machines,
When there is a ball in the winning hole or the like, the generation of the random number created by the software and written in the ROM is stopped, and when the random number at that time coincides with the preset hit value, the hit is generated. In the above-mentioned conventional technique, since the numerical value of the predetermined value is circulated in a certain cycle, there is a bias in the winning rather than in the perfect random number. Also, because the random number created by the program was written in the ROM, it is possible to convert it to a ROM with a changed probability of hitting, or find a program that causes a hit exceeding the authorized probability under certain conditions from the outside. By putting in a ROM in a form that is hard to be tampered with, there were cases where fraud was easily made. By the way, from summer to autumn 1993, a newspaper magazine reported an illegal case that changed the probability of pachinko parlors.

[0003]

In conventional pachinko machines and game machines, a predetermined number of values is circulated in a certain cycle as a method of obtaining a random number for generating a hit .
Since this circulation depends on the internal clock, there is a problem that it is not a perfect random number but is unevenly distributed. Also, since the random numbers created by the program were written in the ROM, the ROM with changed probability and the regular ROM
There was a problem that you could convert and. An object of the present invention is to provide a random pulse generator that is not biased and cannot be tampered with by utilizing radiation that naturally decays. The prior application to which the present application is related is Japanese Patent Application No. 5-100164 by the same inventor. An object of the present invention is to provide a method for eliminating hit bias and determining a hit occurrence under a predetermined probability corresponding to a more complete random number, and a random pulse generator having no hit bias.

[0004]

In order to achieve the above-mentioned object, the present invention captures α, β, and γ rays emitted by radioactive substances as particles having a predetermined energy level. The point that the radiation distribution of particles follows the distribution of an exponential function, and the probability Pk that the number of the particles radiated in this exponential function is k in a predetermined time interval.
Is a point displayed by Poisson's distribution formula and the number k of particles is randomly emitted according to a certain probability, and a count value of particles detected by a radiation detection circuit,
In a random pulse generator that compares a preset reference value that gives a certain probability and generates a pulse per hour when they match, a weak radioactive material and a predetermined solid angle of exposure that is placed facing the radioactive material. The semiconductor detection element that occupies, and converts the particle into an electric signal with an intensity corresponding to the energy level, an amplification circuit that generates and amplifies the time constant signal from this electric signal, and this time constant signal corresponds to the particle The pulse height discriminator that discriminates energy levels in the specified intensity range, the counting circuit that counts and holds the discriminated signal as the number of particles, and the counting time for continuing the counting operation for this counting circuit by programming. A setting circuit that can be changed, a memory that can change the reference value that gives the target probability by programming, and a total A comparison circuit that compares the count value held in the counting circuit with the reference value within a period of time and outputs a pulse if they match, and an adjustment mechanism that adjusts the distance between the radioactive substance and the semiconductor detection element to change the solid angle exposed. Composed from.

[0005]

Function: The counting time and the reference value are fixed according to the target probability, and the adjustment mechanism is used to adjust the gap between the radioactive substance and the semiconductor detection element so that the measured number held in the counting circuit becomes the reference value corresponding to the target probability. By adjusting the distance of, the exposure solid angle is changed, and the absolute number of radiated particles received by the semiconductor detector is changed to obtain the target hit probability. The adjusting mechanism rotates a screw supporting the radioactive substance to adjust the distance between the radioactive substance and the fixed semiconductor detection element.

[0006]

The present invention will be described below with reference to the drawings. Embodiments of the present invention will be described with reference to the drawings. FIG. 5 is a diagram showing the principle of the random pulse generator according to the present invention. Nuclides of natural or artificial radioactive substances radiate α, β, γ rays and spontaneously decay, in which case they decay according to a predetermined decay constant specific to each substance. As described in the evening edition of page 10 of Nikkei newspaper on November 24, 1993, the process (decay) of unstable atoms that emit radiation to become other atoms occurs with "a certain probability determined by the type of atom". It is a thing. In the present application, a very small amount of radioactive substance that does not affect the human body is used.
A trace amount of radioactive material is used in this application by Amersham of the United Kingdom, which is widely used in Japan for smoke detectors.
I am using 1 Am. The α, β and γ rays emitted successively from such a radioactive substance are detected at predetermined time intervals. For simplicity, the explanation will focus on the α ray. For example, with Americum 241 Am, A number of α rays (helium atoms) are emitted per unit time (1 to 500 /
Seconds). However, even if A pieces are released in a certain unit time, since it is a natural phenomenon, there are cases in which 20 pieces are released, 36 pieces are released in a certain unit time, and there is no release at all. However, it is a fact that if it is measured for a long time, A pieces are emitted with a certain probability at a certain unit time and B pieces are emitted with another probability (details will be described later).

The function of exponential distribution representing the natural collapse is the density function represented by the formula F (t) = Ae {-λt} (1) representing the graph of FIG. Below, the number in {} indicates an index .
This average value is 1 / λ. This average value corresponds to the average value of the emission time intervals of one α ray, and therefore the number of α rays detected in a certain unit time is 1 / (1 / λ) = λ. The decay constant of λ is known almost exactly not only for Americum Am but also for existing nuclides. In order to detect the emission of α rays, it is easier to detect the number of α rays emitted in a certain time zone than to measure the detection time interval. For the decay of americum, the emission time interval of one α-ray matches the exponential function F, so the number of α-rays emitted in a certain time zone may be detected.

A function F (t) = whose radiation distribution shows an exponential distribution
When Ae {-λt} is followed, the number of α-rays that collapse in the observation time interval h, (a, a + h) at an arbitrary time a is k.
The probability Pk of being individual can be expressed by the following equation. Pk = e {-λt} · (λh) {k} / k! (2) Here, k = 0, 1, 2, 3, ..., k! Is the factorial of k. This distribution is a Poisson distribution, irrespective of the starting point a of the time section, and its average value is λh. Therefore, the average number of α rays radiated in a unit time is λ when h = 1 hour. The equation (2) is solved for the number k to obtain the following equation.
That is, k = G (e · Pk · λ · h) (3). Here, e is a natural logarithm, λ is a decay constant of the americum Am, probability Pk is 1/220, and h is CP.
Clock frequency f or 1 / f of control circuit such as U
Set appropriately with.

The probability Pk = 1/220 is a hit probability determined by the pachinko machine industry or the law, and invites a proper euphoria,
It is a proper probability for a healthy game that does not run gambling. The frequency f is 20M in the current CPU.
Since it is Hz, h can also be determined. Further, k is the number of α-ray particles that can be detected by a predetermined detector. Now, the inventor of the present application has clarified the principle of random numbers based on the RI, and has manufactured a random pulse generator to which a radiation detector for detecting the number of α-ray particles is applied.

In FIG. 4, the radioactive capsule 30 includes:
The artificial radionuclide Americum 241 Am, which emits minute amounts of α, β, and γ rays that are harmless to the human body, is stored. The α, β and γ rays emitted from the radioactive capsule 30 are detected by the detection device 31. The radiation is converted by the detector 31 into an electric signal corresponding to the energy level. The detection device 31 detects all the particles within the solid angle ω occupied by the detection device 31 one by one from the α, β, and γ rays emitted from the americum Am, and outputs a detection signal to the discrimination circuit 32. . The discrimination circuit 32 selects a specific radioactivity α ray from the signals of all the emitted particles according to the energy spectrum, and counts the selected α rays within a set predetermined time h. The discrimination circuit 32 outputs the counted value (number) to the counter 36. In the counter 36, the counted number of decay α rays input from the setting circuit 33 at a predetermined time interval h (measurement time) is accumulated and held for the set time h (for example, about 1 second) and held. .

A predetermined time interval h (measurement time) is input from the setting circuit 33 to the discrimination circuit 32, and the energy level of radioactive particles is set from the input device 45 such as a variable resistor. The cumulative value x of the counter 36 and the reference value k0 in the read-only memory ROM 37 are compared by a comparison circuit 38.
Compared with. In the ROM 37, regarding the α ray,
For example, the number k0 of constants giving the probability Pk = 1/220 is recorded. If the probability Pk is other than 1/220, the reference value k0 also changes. The comparison circuit 38 outputs the coincidence signal p to the drive circuit 39 when the value x matches the fixed value k0. Upon receiving the coincidence signal p, the drive circuit 39 outputs a winning display to the electronic display device 40.

If there is no coincidence signal p, the drive circuit 39 outputs an out-of-range display and the out-of-range number is displayed. Whether or not the value x becomes the fixed value k0 is a probability of 1/220, and therefore the coincidence signal p is randomly generated with a probability of 1/220. The setting circuit 33 receives the activation pulse from the start circuit 34 and opens the mask of the measurement time h in FIG. In the pachinko machine, the sensor 34 detects that a ball has entered the winning opening 35, and generates a start pulse.

The radioactive capsule 30 and the detection device 3 of FIG.
1, the configuration and function of the discrimination circuit 32, the setting circuit 33, and the ROM 37 will be described in more detail with reference to FIG. The present inventor
The radioactive capsule 30 and the detection device 31 were enclosed in a copper can and arranged so that the occupied solid angle ω in the radiation space with respect to the nuclide could be changed. The detection device 31 will be described here using a PIN diode of a semiconductor detector as an example. Ionization chamber,
GM tubes, scintillation counters, comparison counters, other semiconductor detectors such as Ge detectors can also be used in the detection device.

In FIG. 6, the detecting device 31 comprises a PIN diode D, a coupling capacitor Cc, a protection resistor R, a preamplifier 43, a resistor Rf for setting a time constant, a capacitor Cf and an amplifier 46. The weak signal detected by the PIN diode D is the preamplifier 43 and the amplifier 46.
It is amplified into a discharge type pulse signal having a voltage level proportional to the intensity of radiation. For the PIN diode D, a commercially available metal can sealing type is used by removing the metal portion on the top surface to expose the surface of the silicon element. P in the radioactive capsule 30
The silicon surfaces of the IN diode D were made to face each other and housed in a box-shaped metal can to prevent (natural) α rays from entering from the outside. Bias voltage V is PIN via protection resistor R
It is applied to the diode D, and the PIN diode D is pn
It is a coupled semiconductor, and when charged α-rays enter, unstable electrons and unstable positive holes move, so-called current flows, P
Voltage fluctuations occur across the IN diode D.

This fluctuating voltage is weak and is sent to the preamplifier 43 via the coupling capacitor Cc, where it is current-amplified. This amplified current is fed back by the resistor Rf and the capacitor Cf, and outputs a time constant signal n that generally describes a known discharge voltage curve to the amplifier 46. Amplifier 4
6 amplifies this time constant signal n and outputs it to the discrimination circuit 32. The discrimination circuit 32 includes high, medium and low three-discrimination circuits,
Each discrimination circuit includes a first comparison circuit 50, a second comparison circuit 51, and a third comparison circuit 52. Each of the comparison circuits 50 to 52 is an integrated circuit (IC), and is a discrimination circuit for separating a signal output from the amplifier 46 from a signal due to radiation and an external noise. First comparison circuit 50
Represents the high voltage e1 for comparison and the time constant signal n, the low voltage e2 for comparison in the second comparison circuit 51 and the time constant signal n, and the third comparison circuit 52 in the intermediate position voltage e3 for comparison. The time constant signal n is compared with each other.

The reference voltage e1 applied to one input terminal of the first comparing circuit 50 is the upper limit voltage for discriminating the high wave height shown in FIG. 7, and the first comparing circuit 50 of the discriminating circuit has the high wave height, that is,
This is a circuit that distinguishes high voltage pulses as noise. The reference voltage e2 applied to one input terminal of the second comparison circuit 51 is a low voltage for discriminating the lower limit wave height shown in FIG.
This discrimination circuit is a circuit that discriminates a pulse having a low wave height, that is, a low voltage on the contrary, as noise. Third comparison circuit 52
The reference voltage e3 applied to one of the input terminals is an intermediate voltage (not intermediate between e1 and e2) of the wave height of the time constant signal n itself, and this discrimination circuit discriminates at a voltage higher than the intermediate voltage.
Generates timing signals. The intermediate voltage is exactly the voltage at the intermediate position of the time constant signal n shown in FIG. 8 (for picking up all signals first and later distinguishing them). Each of these reference voltages decreases in the order of e1, e2, and e3, and is set as predetermined by the energy level.

The charged α-rays enter the semiconductor detection element to move the unstable electrons and the unstable positive holes which are weakly coupled to each other, thereby causing a voltage fluctuation across the PIN diode D. Cancellation circuit 53 consisting of an integrated circuit of the flip-flop (IC), the first delay circuit 54, the first rectangular pulse generating circuit 56, second delay circuit 55, a second rectangular pulse generating circuit 58, the third rectangular pulse generating circuits 59 Is a timing adjustment circuit for the signals discriminated by the comparison circuits 50 to 52 of the discrimination circuit. Regarding these mutual operations, FIGS.
Will be described below.

When the time constant signal n is noise higher than e1, the first comparison circuit 50 outputs the first discrimination signal A1 to the cancellation circuit 53, and the cancellation circuit 53 receives the first discrimination signal A1 and cancels the signal c. Is output.

The second comparison circuit 51 outputs a second discrimination signal A2 to the first delay circuit 54 when the time constant signal n is a signal of the α ray higher than e2, and the first delay circuit 54 outputs the second discrimination signal. When A2 is received, the first delay signal D1 having a duration about several times longer than that of the second discrimination signal A2 is output to the first rectangular pulse generation circuit 56 at the time of rising. The first rectangular pulse generating times <br/> circuit 56 at the falling thereof falling receiving first delay signal D1, and outputs a first determination signal J1. Cancel circuit 53
The cancel signal c from is sent to the first delay circuit 54, and when the cancel signal c is received by the first delay circuit 54, the output of the first delay signal D1 is stopped.

The second discrimination signal A2 is also sent to the second delay circuit 55.
The second delay circuit 55 outputs the second discrimination signal A2
In response to this, the second delayed signal D2
And outputs it to the rectangular pulse generating circuits 58. This second delay signal D2 is approximately several times longer in duration than the second discrimination signal A2,
The first delay signal D1 and the end time are the same. The second rectangular pulse generating circuits 58 when falling the trailing receives a second delayed signal D2, and outputs a second determination signal J2. The cancel signal c from the cancel circuit 53 is the second rectangular pulse generation.
Are sent to the even circuits 58, a cancel signal c second
When the rectangular pulse generator circuitry 58 is received, it stops the output of the second determination signal J2. This is higher voltage than e2,
The α-ray signal and the noise signal having a high wave height are also included, and the noise signal is eliminated by the cancel signal c.

The third comparison circuit 52 is a time constant signal n outputs a third discrimination signal A3 as a result is higher than e3 Third rectangular pulse generating circuits 59. The third rectangular pulse generating circuits 59
Receives the third discrimination signal A3 and outputs the third judgment signal J3 at the falling edge. Three kinds of first, second, third
The determination signals J1, J2, J3 are input to the condition input terminal of the first AND circuit 60, and the first AND circuit 60 outputs the detection signal K to one condition input terminal of the second AND circuit 62 when these three kinds of conditions are satisfied. . In the lower part of FIG. 6, the second AND
The mask pulse h of FIG. 8 is input from the setting circuit 33 to the other input terminal of the circuit 62. This mask pulse h
During the duration of, the second AND circuit 62 takes in the detection signals K that have sequentially arrived and outputs them to the counter 36. The counter 36 accumulates and holds the incoming detection signal K having a counting function. The setting circuit 33 is set to 1.0, 1.5, 2.
It was set to be 0 seconds.

When the amplification degree and the standard of the preamplifier 43 and the amplifier 46 are set, the time constant signal n output from the amplifier 46, that is, the voltage fluctuation value can be predicted for α line, and V =
It can be determined by V0e [-aRfCft]. Specifically, in the case of α rays, the voltage fluctuation value that is determined in accordance with the design specifications of the discrimination circuit 32 as a whole is determined such that the high voltage is between e1 and the low voltage is between e2. Therefore, on the discrimination circuit 32 of the present embodiment, the α ray is counted only when the observed voltage fluctuation value is between the high voltage e1 and the low voltage e2. When the voltage fluctuation value is high voltage e1 or more, the cause of the influence is mostly due to high energy due to lightning strikes or sparks from motors,
Since it is not an α ray, it is regarded as noise and is not counted in the number of particles. Further, when the voltage fluctuation value is lower than the voltage e2, it is mostly due to attenuated natural radiation or due to the internal noise of the PIN diode D, and since it is not an α ray, it is not counted as noise.

In the discrimination circuit 32 of this embodiment, the voltage fluctuation value is between 3V and about 4V. Therefore, the high voltage e1 is 4.5V, the low voltage e2 is 1.8V, and the voltage e3 is 1.3V. Set to. In addition, the discharge time of the time constant signal n is 40 μsec at maximum, which is a resolution accuracy that can be counted even when 30,000 to 40,000 α-rays (helium particles) arrive in one second. Since the number of collapses of the americum is at most about 1 to 500 / second, it is possible to detect with high accuracy even if the signal delay on the circuit and the variation of the rising accuracy of the pulse are included in the calculation.

Now, in FIG. 7, various time constant signals n, which discharge with time, are plotted on the horizontal axis as n1, n2, and n.
3 and n4, and the vertical axis shows the signal waveform at each point of the discrimination circuit 32 of FIG. 6 in the form of wave height. First, the so-called positive definite signal n1 whose voltage fluctuation value indicates α rays (helium particles)
(When between high voltage e1 and low voltage e2),
A portion having a voltage fluctuation value equal to or higher than the low voltage e2 is detected by the second comparison circuit 51 in FIG. 6 (there is no high voltage e1.
Nothing is detected by the comparison circuit 50), and the second discrimination signal A2
Is generated and output to the first delay circuit 54. This second
At the same time when the discrimination signal A2 rises, the first delay circuit 54 generates a wide first delay signal D1 to generate a first rectangular pulse.
And outputs it to the circuitry 56. The second discrimination signal A2 is also output to the second delay circuit 55, and the second discrimination signal A2 generates the second delay signal D2 of a slightly wider width in the second delay circuit 55 at the same time when it falls, and the second rectangular pulse to output to the generation circuits 58. The first rectangular pulse generating circuits 56 and outputs a first determination signal J1 at its falling receiving first delay signal D1 to 60, at the same time the second delay circuit 58 falls its start receiving a second delayed signal D2 (The duration is set so that the falling edges match when D1> D2), and the second determination signal J2 is output to the first AND circuit 60.

Further, the voltage portion of the intermediate position is detected by the third comparator circuit 52 which corresponds to the voltage e3 or more parts, the third third rectangular pulse discrimination signal A3 is generated generated circuits 59
Is output to. The third third rectangular pulse generator circuitry 59 simultaneously with the fall of the discrimination signal A3 generates the third determination signal J3, and outputs to the 1AND circuit 60. The first AND circuit 60 includes a first judgment signal J1, a second judgment signal J2, and a third judgment signal J2.
The detection signal K is output only when all the judgment signals J3 have been obtained.

The above is summarized as shown in FIG.
A signal pulse that is higher than the low peak detection voltage and lower than the high peak detection voltage is regarded as a pulse generated by radiation, and a timing signal generated by the intermediate peak value is added to this signal pulse.
In addition to the D circuit 60, only the signal due to the radiation to be detected is passed.

The second AND circuit 62 passes the detection signal k coming (generated) from the first AND circuit 60 during the valid period (operation continuation permission time) h given in the form of a pulse from the setting circuit 33, and the counter 36. Output to. The setting circuit 33 includes a frequency divider 70 having a built-in crystal oscillator and a dip switch 71. The dip switch 71 is appropriately turned on / off to set a binary number. Thus, the frequency division ratio of the frequency divider 70 is determined, and the effective period h of the measurement is set to, for example, 1.0, 1.5, 2.
It can be set to 0 seconds.

The counter 36 that receives the count value k counts and holds the number of pulses that have arrived (generated) during the valid period (operation continuation permission time) h. The ROM 37 can express a 16-bit binary number by setting the DIP switch to (0, 1) by turning on and off.

A ROM is connected to one terminal of the comparison circuit 38.
A signal representing the reference value k0 by turning on / off the DIP switch 37 and a signal representing the count value k from the terminal of the counter 36 are applied to the other terminals.

The comparison circuit 38 compares the set value (reference value) of the ROM 37 with the count value of the counter 36 for each bit,
When they match, one hit pulse is output. Now, here, the counter 36 holds a value obtained by counting (adding) the effective period h of the measurement determined by the frequency divider 70, for example, for 1.0 second. When the measured value and the set value k0 (reference value) of the ROM 37 match, the comparison circuit 38 outputs a pulse, and this pulse is used as a hit. For the matching rate, the target probability is, for example, 1/220.

The reference value k0 is set in advance in the ROM 37 by a DIP switch and the frequency divider 70 of the time setting circuit 33 is set.
, The time interval h is set by the DIP switch 71. The counter 36 is cleared at every counting time by the reset signal R after finishing the hit / no hit.

Radiation that decays in a certain time (count value)
Is a phenomenon according to the law of probability, and therefore, even if a certain radiation source is counted for a certain period of time, the count value does not always become a constant value, and values dispersed around a certain average value M are obtained. This dispersion is given by the Porin distribution formula. Where p (m)
Is the probability M that an m count (the number of pulses) can be obtained in a certain period of time is the average value of m when measured many times, and when M becomes several tens or more, the Gaussian distribution formula {} represents an exponent. Is equal to (See Figure 3)

This probability is not always constant, and in some cases, it may be coincident only by counting several times, or may not match even after counting hundreds of times, and if it is counted many times, it has a predetermined probability. That's what it means.

Americum A prototyped by the inventor of the present application
The results of observation experiments of a random pulse generator that counts α rays (helium particles) of m are shown below. Regarding the occurrence probability, the measurement data in Table 1 below shows 10800 observations (18 valid times h = 1.0 seconds in FIG. 8) counted every 1 second (18
0 minutes) It was executed. Regarding the peak value and the occurrence probability of the selected CPS (the number of pulses per second), the measured value and the theoretical calculated value are shown below.

The peak value and CPS arbitrarily selected from Table 1
The probability of can be read as follows. Measured value Calculated value Number of times of measurement 10800 Peak value 229 CPS occurrence probability 298/10800 = 1 / 36.2 1 / 37.9 0.0275 Selection CPS 200 CPS occurrence probability 42/10800 = 1 / 257.1 1/237 0.00389 Therefore, the occurrence probability of the selected CPS is deviated. However

Selected CPS Occurrence Probability Occurrence Probability Measured Value Calculated Value 199 CPS 1/270 1/270 200 CPS 1/257 1/237 201 CPS 1/177 1/210 202 CPS 1/180 1/186 203 CPS 1/164 1/167 Moreover, even with this number of counts, the difference of 1 CPS does not cause a difference of about 1/20 to 1/30 in the probability of occurrence, so it is more and more acceptable as it counts a large number of times in practice. Enter the range. The number of counts of measured values is shown in Table 1 below.

Table 1 CPS Count CPS Count CPS Count CPS Count 171 1 202 60 60 230 274 258 42 172 1 203 203 66 231 254 259 411 41 175 1 204 69 69 232 286 260 331 176 1 205 205 92 233 255 261 34 35 17 234 262 28 179 1 207 104 104 235 281 263 14 180 180 1 208 127 127 236 232 264 27 181 1 209 109 237 238 265 14 182 1 210 210 152 238 244 266 14 183 2 211 211 151 239 2 216 218 261 267 2 10 185 6 213 189 241 182 269 269 8 186 5 214 175 242 182 270 7 875 215 193 243 173 273 271 5 188 3 216 196 244 175 272 8 8 189 10 217 230 245 166 273 3 190 218 218 218 246 147 274 1 3 19 217 219 231 247 247 2 326 173 275 275 221 262 249 107 277 2 194 24 222 274 250 250 103 278 2 195 31 223 253 251 114 114 279 2 196 28 224 249 252 290 280 1 197 29 225 269 253 253 67 67 282 1 198 42 226 261 275 284 254 254. 255 54 487 1 200 42 228 272 256 65 497 1 201 61 229 29 257 40

A graph of the values in this table is shown in FIG. Further, FIG. 2 shows a graph in which the number of times of measurement 10,800 times is repeated three times. It can be seen that the experimental value graph more closely approximates the Gaussian distribution of theoretical values when the number of measurements is gradually increased. The method of setting the hit probability according to the graph of this experimental value is as follows. 1/220 = 0.0 that was allowed on the pachinko machine for this prototype
Since there is no count value that gives the probability of 045, it will be explained experimentally with 1/257 = 0.00389, which is close to the probability of 1/220. As shown by the arrow in FIG. 1, first, the probability 1/257 =
Count value 200 CPS from the intersection of 0.00389 and the graph
Then, 200 is set in the ROM 37 in advance as a reference value.

In manufacturing a practical device, the circuit is burned by programming the DIP switch of the ROM 37 so as to be a binary number of a target reference value. The circuit is burned by programming the dip switch 71 of the setting circuit 33 so that the effective period of measurement is, for example, h = 1.0 seconds. Further, if the effective period of measurement h = 1.0 seconds is increased or changed, the peak count value of the graph is increased or changed while the distribution shape is maintained as shown in FIG. 9, and the probability given by each count value is also changed. , 1/220 = 0.0045
The selected CPS to obtain the probability of can be found by changing the effective period h = 1.0 seconds (details will be described later).

For the data in Table 1, in order to verify the randomness, a peak value of 229 CPS and a selected value of 200 C
Looking at the occurrence intervals of PS and the number of measurements within 10800, the minimum occurrence interval of the peak value 229 CPS is 2 seconds and the maximum occurrence interval is 171 seconds, and there is no regular occurrence of hits. It can be understood. In addition, the minimum interval between occurrences of the selected count value of 200 CPS is 7 seconds,
It can be seen that the maximum interval is 1211 seconds later, and here again there is no regularity.

Therefore, in order to converge the measured value k to the target value range of the probability, firstly, the ROM 37 and the setting circuit 33 are fixed, the positions of the nuclide and the detector are changed, and the incoming and outgoing solid angle ω is changed. Then, there is a method of adjusting the absolute number of α rays. In the second method, there is a method in which the incident solid angle ω is fixed, the absolute number of irradiation α rays is fixed, and the conditions of the ROM 37 and the setting circuit 33 are changed. When the random pulse generator of the present application is used only for a game machine such as a pachinko machine, the circuit constant is fixed and the positions of the nuclide and the detector are changed in accordance with the predetermined probability of 1/220 and the like. Change the incoming and outgoing solid angle.

Now, in the random pulse generator which gives the probability shown in FIG. 1 (Table 1), when the measurement time (measurement operation duration) h is increased from 1.0 seconds to 1.5 seconds and 2.0 seconds, The number of particles observed within the measurement time h increases. Therefore, in the graph of FIG. 1, the peak count value and the like move in the increasing direction as e → f → g in FIG. 9 while maintaining the shape of the Gaussian distribution.

Next, when the intensity of the radiation source in the radiation capsule 30 is increased while the measurement time (measurement operation duration) h is set to 1.0 second, the particles observed within 1.0 second The number k naturally increases. Therefore, in the graph of FIG. 1, the peak count value and the like of FIG.
It moves in the direction of increase like f → g. AM in this application
ERSHAM's Amerishum Am film uses weak nuclides that are harmless to the human body. Therefore, while the intensity of the radiation source remains constant, the positions of the nuclide and the detector can be changed to change the incoming and outgoing solid angles. , Pursue a method of adjusting the absolute number of α rays.

Here, the number of particles radiated in a three-dimensional space from a radiation source having a constant intensity will be described with reference to FIG. The solid angle of the spherical surface QQ at the center O of the sphere Q is 4π.
And the solid angle ω formed by the area S around the point P on the spherical surface at the center O is 4π · S / 4πr2 = 4π · S / 4π
r2, which decreases in inverse proportion to the square of the distance. A source Amerisum Am is placed near the center O, and a PIN diode D is placed at a distance r from the center O. At this time, it is approximately considered that the sensitive surface of the detector PIN diode D is located on the spherical surface of the sphere Q facing the radiation source. The area of the sensitive surface of the PIN diode D toward the center O is S, and the radiation source Amerisum Am is deviated from the center O, but it is treated as if it is approximately at the center O and treated as the radiation source Amerisum Am. Approximately the distance R with the PIN diode D,
Let r = R, which is the radius of the sphere.

Since the radiation is emitted from the radiation source in the entire space 4π direction, the number C of the radiation reaching the detector PIN diode D is inversely proportional to the square of the distance between the source and the detector. Expressed as a formula, it is given by. Where C is the expected count value for one second (cps) (average when observed many times) S is the sensitive area of the detector (mm2) A is the intensity of the radiation source (μCi: microcurie) R is the detection Distance between instrument and radiation source (mm) 1Ci = 3.7 × 10 10 (Bq): Stable data.

For example, if the intensity of the radiation source is 1 μCi, the sensitive area of the detector is 1 mm 2, and the distance between the detector and the radiation source is 3 mm, then C = 327 cps. Here, if the distance R between the detector PIN diode D and the radiation source Amesume Am is changed, the counter 36
The count value k of can be changed. Here, substituting c = 327 calculated above as M = m into the equation (5), P (3
57) = 1 / 45.3, which means that the probability that the count value will be 357 is 1 in 45.3. The probability of 1/220 determined by the pachinko industry or the law is about 295 per second.
Will be obtained at. Here, if 295 is set in advance in the comparator and a pulse is output when the count value becomes 295 and they match, a random hit with a probability of 1/220 can be obtained. When the adjustment mechanism of the present application is used to change the distance between the radiation source and the detector to set c = 340, the probability that the count value 295 is obtained is about 1/908.
In this way it is possible to adjust the source and detector. Of course, it is possible to change the probability by keeping the distance constant and changing the set value. Even in this case, since the intensity of the radiation source is accompanied by a measurement error and an error due to variations in manufacturing, this mechanism is effective for adjusting the average count value to a constant value.

The detector PIN diode D is shown in FIGS.
The mechanism for changing the distance R between the radiation source and the radiation source Amerisum Am will be described in detail. A base 1 incorporating the circuit of FIG. 6 is provided with a mounting bracket 2 having an L-shaped cross section, and the mounting bracket 2 includes a vertical portion 3 and a horizontal portion 4. The vertical portion 3 is provided vertically to the base 1, and the horizontal portion 4 is parallel to the base 1 and is integrally formed with the vertical portion 3. The vertical part 3 is made of metal,
It is connected to the ground side of the board 1 by soldering or the like. A detector PIN diode D is fixed via a spacer 5 on the base 1 surrounded by the mounting bracket 2, and each electrode of the diode D is connected to the circuit of FIG. A screw hole is formed in the center of the horizontal portion 4, and a screw 6 is screwed into the screw hole. A flat base portion 7 is fixed to the tip of the screw 6 on the base 1 side, and a film 8 having an area S of an americanism Am is fixed to the base 1 on the base portion 7 parallel to the base 1. Screw 6
A bolt 9 for locking is screwed into the rear end portion above the horizontal portion 4.

The radiation source Am and the PIN diode D separated by the distance R are in the positional relationship of the solid angle ω of the sphere Q in FIG. Further, a copper shield case 10 covers the mounting bracket 2, the radiation source Am, the PIN diode D, and the like. The shield case 10 is connected to the ground of the base 1.

As to other experimental examples, in the formula (3) and the prototype device of the present application, S = 1.21 mm 2, A = 1 μCi =
In the case of 3.7 × 10 4 Bq, the distance R and the count count C
The relational data of is as follows. Here, the screw 6 is rotated by a screwdriver or the like to change the distance R between the detector PIN diode D and the radiation source Am.

[0050]           Count count of signal source and detector           Distance R (mm) C (CPS)               5.0 142               4.0 222               3.0 395               2.0 890               1.0 3562

By the way, since radiation that decays in a certain period of time is a phenomenon according to the law of probability, even if a certain radiation source is counted for a certain period of time, the count value does not always become a constant value, and it is in the vicinity of a certain average value M It has already been described that the above-mentioned dispersion results in the dispersion shown in FIG. Nevertheless, the distance R between the signal source and the detector
The average value M of the count number C is decreased as shown in FIG.
It can be understood that there is a tendency to increase as shown in. However, this count value is a reference value because it is a count obtained by the preamplifier and the actual count is a pulse that has passed through the discrimination circuit.

Next, a method of setting the reference value k0 of the number k that gives the probability 1/220 in the mass production site of the random pulse generator will be described. First, one random pulse generator is selected as the sample device. By the setting circuit 33, the counting time h is 0.8 seconds, 1.0 seconds, 1.3 seconds, 1.
5 seconds and 2.0 seconds are sequentially set, and the same measurement as when collecting the data in Table 1 is performed for each set time. The measurement data is taken for each, and a graph similar to that of FIG. 1 is created to find the reference value k0 of the number k that gives the probability 1/220. R to give this reference value k0
The position of the OM37 DIP switch is selected and fixed later. Further, the position of the DIP switch of the setting circuit 33 to which the counting time h0 at that time is given is also fixed. Still further. Distance R between the source Amerisum Am and the detector PIN diode D
To record. This distance R is determined by the pitch position of the screw 6, and is proportional to the rotation speed and angle. With this, the circuit constant and the distance R of the sampling device that outputs the pulse having the target probability are determined.

For a large number of mass-produced products, each setting constant and the distance R are first adjusted to the sampling device. That is, the position of the dip switch of the ROM 37 and the position of the dip switch of the setting circuit 33 to which the measurement time h is given are fixed according to the sample device. Next, for the distance R, the pitch position, the rotation number, and the angular position of the screw 6 are adjusted to the same position as the sample device. However, since the mounting bracket 2 and the like are mechanical, and the radiation source Amerisum Am film 8 also has a variation of about 5%, the distance R needs to be finely adjusted in order to obtain the same probability as the sample device. There is.

Next, the mass-produced products for which the reference value k0 and the measurement time h0 are set are connected to recording devices for recording the number of hit pulses, and the power is turned on. Prepare a large number of mass-produced products and recording device combinations. In this way, a large number of mass-produced products, which are in the state of collecting data, are placed on the belt conveyor and arranged so as to return to the check point after 30 minutes. From Table 1, in order that the count value k0 has a probability of 1/220,
It is sufficient that the count value k occurs approximately 49 times in 10800 times / second, that is, in 180 minutes. Therefore, for 30 minutes, it may be 49 times x 30 minutes / 180 minutes = 8.1 times. When one mass-produced product arrives at the checkpoint after 30 minutes while continuing to collect data, the recording frequency of the recording device is checked by a predetermined reading device.

When the number of occurrences is smaller than "8.1" such as "7", the distance R is large and the solid angle is small, and the probability distribution graph shown in FIG. 9 is moved to the left in the figure. Is. This is a reduction in the absolute number of emissive particles that the detector PIN diode D is exposed to. Then, slightly rotate the screw 6 in FIG.
The distance R is reduced, the solid angle ω is increased, and the detector PIN is
Increasing the absolute number of emissive particles that the diode D receives. On the contrary, when the number of occurrences is larger than "8.1" such as "9", the distance R is small and the solid angle is large.
The detector PIN diode D is an increase in the absolute number of emissive particles irradiated. Therefore, the screw 6 is slightly rotated in the loosening direction to increase the distance R, reduce the solid angle, and reduce the absolute number of the radiated particles with which the detector PIN diode D is irradiated.

Even in a mass-produced product with the distance R deviated, the adjustment can be accurately completed as a hit generating device with a probability of 1/220 by checking at most twice, that is, re-inspecting one hour later.
Of course, mass-produced products with no deviation in distance R will be
The inspection is finished after 0 minutes. Since many mass-produced products to be inspected are put on the conveyor in advance, the inspection work can be continued without a break when many are in the state of collecting data.

After setting the distance R, the screw 6 is locked by the nut 9, and the screw 6 and the nut 9 are fixed by an adhesive.
The set value of the distance R at the time of completion is about 3 to 4 mm, and the screw 6 and the nut 9 are fixed with an adhesive. Finally, the screw 6, the nut 9, the mounting bracket 2 and the like are covered with a shield case 10 and sealed.

For other game machines whose hit probability is another value, the circuit can be printed by changing the above-mentioned reference value of the random pulse generator. In such a pachinko machine or the like equipped with the random pulse generator of the present application, the probability of hitting once set is constant within 5% at any probability. In the case of a pachinko machine, the player is guaranteed a hit within the legal probability, which contributes to the spread of the pachinko machine as a healthy entertainment. Since the present application uses a natural phenomenon, artificial fraud cannot be done.
In addition, in this example, the α decay of 241 Am was used as a nuclide, and the semiconductor detection element was discharged by the α decay, but RI may be different.

[0059]

As described above, according to the random pulse generator having the adjusting mechanism of the present invention, since the decay of RI which occurs as a random phenomenon in nature is utilized, there is no deviation due to the manufacturing technique or the change with time. , You can create a regular and fair hit probability. In addition, in a pachinko machine equipped with the random pulse generator of the present application, if hits occur continuously, even if so-called Ren-chan occurs, the probability of hitting becomes constant for a long time, such as a unit of a day. The variation due to is eliminated. In the present application, the random pulse generator can be manufactured separately from the pachinko machine, so that the handling is simple, and the verification, test, and manufacturing are easy. Furthermore, this random pulse generator can be applied to not only pachinko machines but also simulation experiments using random numbers.

[Brief description of drawings]

FIG. 1 is a graph of measured data of a random pulse generator of the present invention.

FIG. 2 is a graph diagram of actual measurement data of a large number of times of the random pulse generator of the present invention.

FIG. 3 is a Gaussian distribution diagram for explaining the present invention.

FIG. 4 is a block diagram of a circuit in which the random pulse generator of the present invention is applied to a device for determining the occurrence of a hit.

FIG. 5 is a diagram of an exponential function showing a collapse phenomenon used in the present invention.

FIG. 6 is a block diagram of an entire circuit of a random pulse generator of the present invention.

FIG. 7 is a timing diagram illustrating the operation of the discrimination circuit of the present invention.

FIG. 8 is a timing diagram illustrating the operation of the random pulse generator of the present invention.

FIG. 9 is a Gaussian distribution diagram for explaining the movement of the probability peak due to the variation of the radiation solid angle according to the present invention.

FIG. 10 is a sphere cloth diagram for explaining the principle of variation of the radiation solid angle of the present invention.

FIG. 11 is a side view and a plan view of the adjusting mechanism of the random pulse generator of the present invention.

FIG. 12 is an external plan view of the adjusting mechanism of the random pulse generator of the present invention.

FIG. 13 is a perspective side view of the adjusting mechanism of the random pulse generator of the present invention.

[Explanation of symbols]

1 foundation 2 Mounting bracket 6 screws 8 Americum Am film 9 nuts 10 Shield case 30 radioactive capsules 31 Detector 32 discrimination circuit 33 Setting circuit 34 sensor 36 counter 37 ROM 38 Comparison circuit 39 Drive circuit 40 display device 43 Preamplifier 60 First AND Circuit 62 Second AND Circuit 71 Dep switch D Semiconductor detector h Counting time k count value k0 reference value ω irradiation solid angle R distance

Front page continued (72) Inventor Shunji Ueno 1230 Mukaiyama, Naka-machi, Naka-gun, Ibaraki Prefecture Ikegami Tsushinki Co., Ltd.In Mito Plant Co., Ltd. (72) Hiroyuki Ogawa 1230 Mukaiyama, Naka-machi, Naka-gun, Ibaraki Prefecture Ikegami Tsushinki Co., Ltd. (56) References JP-A-6-291620 (JP, A) JP-A-6-154411 (JP, A) JP-A-5-157847 (JP, A) JP-A-59-114918 (JP, A) Kai 63-55629 (JP, A) JP-A-7-162275 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03K 3/84 A63F 7/02 G06F 7/58

Claims (2)

(57) [Claims] 1. Regarding α, β and γ rays emitted by a radioactive substance, each of these radiations is captured as particles having a predetermined energy level, and the radiation distribution of these particles follows an exponential distribution, and this index In the function, the probability P that the number of emitted particles is k in a predetermined time interval
Focusing on the point displayed by the Poisson distribution formula and that the number k of the particles is randomly emitted according to a certain probability, k is set in advance with the count value of the particles detected by the radiation detection circuit. A random pulse generator that compares a reference value that gives a certain probability and generates a per-hour pulse when they match, occupies a weak radioactive substance and a predetermined solid angle exposed to the radioactive substance. Along with, a semiconductor detection element that converts the particles into an electric signal having an intensity corresponding to the energy level, an amplifier circuit that generates and amplifies a time constant signal from the electric signal, and the time constant signal corresponds to the particles. A wave height discriminator for discriminating between energy levels in the intensity range, a counting circuit for counting and discriminating the discriminated signal as the number of the particles, and this counting A setting circuit for setting a counting time for continuing counting operation to the circuit to be changeable by programming, a memory for setting a reference value for giving a target probability to be changeable by programming, and a counting circuit for setting the counting circuit within the counting time. A comparison circuit that compares the held count value and the reference value and outputs a pulse when they match, and an adjustment mechanism that adjusts the distance between the radioactive substance and the semiconductor detection element to change the exposed solid angle, The counting time and the reference value are fixed in accordance with the target probability, and the radioactive material and the semiconductor detection element are adjusted by the adjusting mechanism so that the measured number held in the counting circuit becomes the reference value corresponding to the target probability. By adjusting the distance between them to change the solid angle of exposure and to change the absolute number of emitted particles received by the semiconductor detector to obtain the target hit probability. An adjusting mechanism for a random pulse generator characterized in that 2. The adjusting mechanism includes a base for fixing the semiconductor detection element, a mounting bracket projecting on the base, a screw screwed to the mounting bracket to support the semiconductor detection element, and the mounting bracket and the screw. And a shield case that encloses the semiconductor detection element, etc., rotate the screw,
The adjusting mechanism of the random pulse generator according to claim 1, wherein the distance between the radioactive substance and the semiconductor detection element is adjustable.