JPH0321957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transmission method for transmitting dose values recorded in, for example, a portable dosimeter to a data processing device such as a computer.

Conventionally, as a portable dosimeter, a method of automatically reading out dose values using a reader has been proposed and put into practical use. As an example, JP-A-54-
There was something disclosed in No. 157647 "Dosimeter data transmission method". In this method, the counting contents of a counting circuit for counting input data are not directly transmitted, but are transmitted as an overflow signal, and the receiving side identifies the counting contents of the counting circuit based on the time point at which this overflow signal is received. Ta. However, a connector was used to connect the dosimeter and the reader. Therefore, noise is generated when the connector is connected, which hinders data transmission, and it is necessary to provide an extra circuit to remove such noise. Also,
Connectors tend to have poor contact, and the number of uses (life) is short, resulting in poor maintainability and reliability. Therefore, it has been difficult to automate the data transmission function and save labor.

When optical fiber transmission technology is applied to data transmission between a dosimeter and a reader, problems related to maintainability and reliability arise, such as an increase in coupling loss of the optical connector due to an increase in the number of times the optical connector is connected and disconnected. Furthermore, when spatial propagation of light is used without using an optical fiber cable, there is a risk that the dosimeter or reader may malfunction due to external light.

In view of the above points, an object of the present invention is to provide a highly reliable data transmission system for a dosimeter.

In order to achieve the above object, the present invention includes a dosimeter having a radiation detector, a dose value counting circuit, and a dose value display circuit, and a reader having a pulse generation circuit that generates a pulse signal of a predetermined frequency and a subtraction counter. and a coupling means for optically non-contact coupling the dosimeter and the reader, supplying the pulse signal to the subtraction counter and also supplying it to the dose value counting circuit via the coupling means, the dose value counting circuit In a data transmission method of a dosimeter, the subtraction operation of a subtraction counter is stopped via a coupling means in response to an overflow of the subtraction counter, and the content of a dose value counting circuit is identified from the content of the subtraction counter.
Each dosimeter was provided with a reed switch that was turned on by the magnetic field of the magnet, so that communication was established between the dosimeter and the reader located within a predetermined distance.

The present invention will be explained in detail below based on the drawings.

FIG. 1 shows an embodiment of the present invention. Here, in the portable dosimeter 10, a radiation detection signal 13 from a radiation detector 11 made of, for example, a GM counter is shaped by a waveform shaping circuit 15, and a pulse signal 17 obtained thereby is shaped by a frequency dividing circuit. Supply to 19.
Now, when the reed switch 21 is turned off, the control signal 25 given to the frequency divider circuit 19 and the AND gate 23 via this reed switch 21
is a low logic level. Therefore, the frequency dividing circuit 19
The frequency division operation of the frequency division circuit 19 is activated, and the first frequency division signal 27 obtained by the frequency division circuit 19 is transmitted to the NOR gate 29.
Then, the second frequency-divided signal 31 is supplied to the alarm setting circuit 33, respectively. The alarm setting circuit 33 supplies a constant frequency monitor signal 35 to the OR gate 37 and the frequency dividing circuit 39 until the dose value based on the count value of the signal 31 reaches the alarm signal generation value set by the alarm setting circuit 33. When the alarm section 41 is configured with a buzzer, a monitor sound of a constant frequency is generated by the monitor signal 35 until the detected dose value reaches the set value of the alarm setting circuit 33. When the detected dose value reaches the set value, the frequency dividing circuit 39 supplies an alarm signal 43 to the OR gate 37. This alarm signal 43 causes
The alarm unit 41 generates an alarm sound.

If the signal 51 supplied to the other input terminal of the NOR gate 29 is at a low logic level, the first frequency divided signal 2
The output signal 5 resulting from the NOR gate 29 in response to 7
3 is supplied to one input terminal of the control circuit 55. The output signal 57 of the AND gate 23 supplied to the other input terminal of the control circuit 55 is at a low logic level due to the reed switch 21 being turned off. When this signal 57 is at a low logic level, the control circuit 55 supplies the output signal 53 from the NOR gate 29 to the counting circuit 61 as a counting signal 59. The counting state of this counting circuit 61 represents dose data obtained by the detection operation of the radiation detector 11. This dose data is supplied from the counting circuit 61 as a data signal 63 to the display circuit 65 and displayed. Display circuit 65
When full scale is reached, counting circuit 61 generates a high logic level overflow signal 51.
Due to this overflow, the light emitting element 71 emits light and the gate operation of the NOR gate 29 is prohibited. The counting operation of the counting circuit 61 is finished, and the dose measurement of the dosimeter 10 is finished. By the way, counting circuit 6
Let N ₁ be the count value of 1, and let N be the count value when the display circuit 65 overflows with respect to the counting circuit 61. Here, when the radiation measurement is completed, this count value N ₁ is read by the reader 100.

When portable dosimeter 10 is placed in position on reader 100, the magnetic field of magnet 111 within reader 100 turns on reed switch 21 within dosimeter 10, causing control signal 25 to go to a high logic level.

The pushbutton switch 121 is operated to set the signal 127 supplied to the AND gate 125 from the oscillation control circuit 123 consisting of a flip-flop to a high logic level. A pulse signal 133 of a predetermined frequency from an oscillator 131 passes through an AND gate 125,
The output pulse signal 135 is transferred to an AND gate 137.
and supplied to the light emitting element 139. Also, the output signal of the flip-flop 141 is transferred to the AND gate 1.
37. When flip-flop 141 is in the reset state, pulse signal 135 passes through AND gate 137 and subtraction counter 138 performs a subtraction operation. Further, the light emitting element 139 emits light in response to the pulse signal 135 , the light is detected by the light receiving element 151 of the dosimeter 10 , and the light receiving pulse signal 153 is supplied to the AND gate 23 .

In such a configuration, it is first assumed that flip-flop 141 is in a reset state. When the pushbutton switch 121 is operated, a pulse signal 135 is generated from the AND gate 125. Since the reed switch 21 is on, the received light pulse signal 153 passes through the AND gate 23 and the first pulse of the output pulse signal 57 is sent to the control circuit 55.
is sent to the counting circuit 61 as a signal 171. As a result, the dose value counted and stored in the counting circuit 61
Latch N ₁ . The control circuit 55 controls the second and subsequent pulses of the pulse signal 57 using the counting pulse signal 59.
The signal is supplied to the counting circuit 61 as a signal. The counting circuit 61 performs counting by adding to the already latched count value _N1 , and generates an overflow signal 51 when the signal count value reaches N- _N1 = _N2 . In response to the generation of this overflow signal 51, the light emitting element 71 emits light, and the light receiving element 181 of the reader 100 detects the light. This received light pulse signal 1
83 is supplied to flip-flop 141 to perform state inversion.

When the push button switch 121 is operated, the counting circuit 61 counts and the subtraction counter 138 performs a subtraction operation based on the pulse signal 135. This subtraction operation continues until overflow signal 51 is generated from counting circuit 61 and flip-flop 141 is inverted from the reset state to the set state. Therefore, the subtraction counter 138 counts and records the count value N- _N2 =N-(N- _N1 )= _N1 ,
Since it matches the recorded count value N ₁ (dose data) of the counting circuit 61 of the dosimeter 10, the dose value can be identified.

At the time the overflow signal 51 is generated and the dose value is read, the Q output signal of flip-flop 141 goes from a low logic level to a high logic level. In response to this level inversion, monostable multivibrator 191 generates output signal 193 that is at a high logic level for a predetermined period of time. Therefore, the output signal 127 of the pulse control circuit 123 becomes a low logic level, and the gate operation of the AND gate 125 is prohibited. This prohibition continues until the push button switch 121 is operated next time.

Since the dosimeter 10 and the reader 100 are coupled by optical means in this way, the drawbacks of the connector method are eliminated. Note that even if the light receiving element 151 of the dosimeter 10 receives external light, the AND gate 23 will not turn on unless the reed switch 21 is turned on, so there will be no malfunction due to the external light.

FIG. 2 shows another embodiment of the dosimeter 10. In FIG. 2, parts having the same functions as those in FIG. 1 are given the same numbers. This second
In the illustrated embodiment, an automatic alarm stop function is added. That is, the counting circuit 61 has a built-in pulse generator 80.
The output of the AND gate 81 is supplied to one input of the AND gate 81. The output alarm signal 43 of the frequency dividing circuit 39 is supplied to the other input of the AND gate 81, and the output of the AND gate 81 is supplied to the alarm automatic stop timer 82.
supplied to The alarm automatic stop timer 82 consists of a counter, which counts the output pulses of the pulse generator 80 guided through an AND gate 81, and when the counted value reaches a set value (for example, after about 2 minutes), outputs an output signal. is supplied to one side of the Noah gate 83. The output alarm signal 43 of the frequency dividing circuit 39 is supplied to the other input of the NOR gate 83 via a NOR gate 84. The output of the NOR gate 83 is supplied to the OR gate 37. In this way, the alarm signal can be automatically stopped after a predetermined period of time.

As described in detail above, according to the present invention, it is possible to eliminate the drawbacks of the conventional method and provide a highly reliable data transmission method for a dosimeter.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of a data transmission system of a dosimeter according to the present invention, and FIG. 2 is a block diagram showing another embodiment of the dosimeter according to the present invention. 10... Portable dosimeter, 11... Radiation detector, 21... Reed switch, 55... Control circuit, 61... Counting circuit, 71, 139... Light emitting element, 100... Reader, 111... magnet, 131
...Oscillator, 138 ...Subtraction counter, 151,
181... Light receiving element.

Claims (1)

[Claims] 1. A dosimeter that has a radiation detector, a dose value counting circuit, and a dose value display circuit, a reader that has a pulse generation circuit that generates a pulse signal of a predetermined frequency, and a subtraction counter, and the dosimeter and the reader that are optically connected. coupling means for non-contact coupling, the pulse signal is supplied to the subtraction counter and also supplied to the dose value counting circuit via the coupling means, and the pulse signal is supplied to the dose value counting circuit in response to an overflow of the dose value counting circuit. In the dosimeter data transmission method, the subtraction operation of the subtraction counter is stopped via a coupling means, and the content of the dose value counting circuit is identified from the content of the subtraction counter. A data transmission system for a dosimeter, characterized in that a reed switch that is turned on by the magnetic field of the magnet is provided for communication between the dosimeter and the reader located within a predetermined distance.