JPS5897798A - Meter sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a meter sensor, in particular a water supply system,
The present invention relates to a meter sensor for automatic meter reading of consumption of gas, electricity, etc.

In order to automatically read the amount of water, gas, electricity, etc. used by each user from a meter reading center via a communication line, a meter is equipped with a signal generator that generates an electrical signal indicating the flow rate, and a meter is equipped with a signal generator that generates an electrical signal indicating the flow rate. A meter sensor has been developed that integrates the electric signals coming from the meter, generates an electric signal indicating the accumulated flow rate, and sends the electric signal indicating the accumulated flow rate to a communication line in response to a call signal from a meter reading center. . In this meter for automatic meter reading, the signal generator uses a magnetic sensor to detect the rotation speed of a magnet attached to a rotating body that rotates with the flow rate of the meter, and sends out a pulse signal with a pulse number proportional to the flow rate. .

The meter sensor measures the pulses of this pulse signal and generates a digital signal indicating the integrated flow rate value.

The conventional meter sensor described above cannot use a mechanical meter that displays a measured value by mechanical means as it is, so it must be replaced with a meter equipped with the signal generator described above, and it is also free from external noise. It has the disadvantage that it is susceptible to influences and tends to deviate from the correct measured value.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a meter sensor that can be attached to an existing mechanical meter, read the measured value displayed by the meter, and generate an electrical signal indicative of the measured value.

The meter sensor of the present invention includes a light emitting part that emits light for illuminating a display part that indicates a measured value of a meter, and a first electric signal that is generated according to a pattern generated by the light reflected from the display part. a photo-taking means having a light-receiving section that generates light, and the first
The image pattern is identified by comparing the electrical signal pattern with a plurality of electrical signals indicating standard patterns prepared in advance corresponding to each measurement value of the measurement display section, and the measurement value of the meter is determined. and output means for sending out a response signal including the electrical signal M2 in response to a calling signal sent from an external device.

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a top view illustrating a portion of a mechanical water meter that displays a measured value of cumulative flow rate. The display section of this water meter 1 includes display digits D1 to D3 for digitally displaying the measured value in units of cubic meters, and digits D1 to D3, respectively.
Display scales A1 and A2 and hands 11 and 12 are provided for analog display of 0 liter and 100 liter units. To read the weighing value ・Display digit D3. D2. All you have to do is read the numbers displayed by DI and the display scale A2°A1 pointed to by pointer 12.11 in sequence. For example, in FIG. 1, the measured value is read as 12.34 m'.

FIG. 2 is a sectional view showing an embodiment of the present invention.

A meter sensor 2 installed above the display part of a water meter 1 includes an electric circuit 3, a light source 4, a light receiving circuit 5.6, and a condenser lens 7 in a cylindrical container made of metal or plastic.
and an objective lens 8.9 are housed and attached. A transparent glass plate is fitted into one end surface of the container of the meter sensor 2, and the end surface faces the display section of the water meter 1. When the meter sensor 2 reads the measured value of the water meter 1, the light source 4 emits light and the light is sent to the condenser lens 7.
The light reflected from the display digit D3 passes through the objective lens 8 and forms an image on the light receiving surface of the light receiving circuit 5.
Further, the reflected light from the pointer 11 passes through the objective lens 9 and forms an image on the light receiving surface of the light receiving circuit 6. Although not shown in the sectional view of FIG. 2, the display digit D2. shown in FIG. The reflected light from the DI and the pointer 12 also pass through corresponding objective lenses and form images on the light-receiving surfaces of the respective light-receiving circuits. In each light-receiving circuit, a charge is generated in each pixel of the light-receiving surface in response to the strength of the incident light, and the height of the voltage proportional to the amount of charge is determined by the clock signal sent from the electric circuit 3. 3 in sequence. electric circuit 3
By comparing the electric signals sequentially transferred from each light receiving circuit with the electric signals indicating the standard pattern, the displayed values of each display digit D3 to D1 and pointer 12.11 are identified and the weighing value is determined. Generates an electrical signal indicating.

3 and 4 are a block diagram showing an example of the configuration of the electric circuit 3 of the meter sensor 2 shown in FIG. 2, and a time chart showing its operation, respectively. The light receiving circuits 5 and 6 of the image processing circuits 28 and 29 each consist of a charge-coupled device (hereinafter abbreviated as COD) T-arrayed imaging section and transfer section. The light source 4 is a light emitting diode. When the light source 4 emits light and illuminates the display section of the water meter 1 as shown in FIG. 2, and the reflected light forms an image on the light receiving surface of the imaging section, each COD forming a pixel in the imaging section
An amount of charge is accumulated depending on the intensity of the incident light. These charges are sequentially passed through the transfer unit in response to clock pulses sent from the control circuit 26, and are converted into a waveform processing circuit as a video signal in which a voltage whose height corresponds to the brightness or darkness of the image for each pixel appears. 120 (or 21). The waveform processing circuit 2 (or 21) compares the voltage of the received video signal with a predetermined threshold voltage, and when the former is higher, it determines the high level (hereinafter abbreviated as H). When the former is lower, it is called a low level (hereinafter abbreviated as "low").
A binarized video signal is sent out. The measurement signal generation circuits 22 and 23 each generate a standard pattern signal synchronized with the binary video signal in response to a pulse sent from the control circuit 26, and compare the patterns of the binary video signal and the standard pattern signal. By this, the digits of each display digit of the water meter and the position of the pointer are determined, and a signal d1 indicating the measured value displayed by the water meter is generated and sent to the message assembly circuit 24.

On the other hand, the input/output terminal 10 is connected to an automatic meter reading device on the meter reading center side via a communication line, and a call signal sent from the automatic meter reading device is applied from the input/output terminal 10 to the input/output circuit 25. The input/output circuit 25 includes a switch circuit that connects a call signal sent from the input/output terminal 10 to the control circuit 2'6, and an input/output circuit that connects the call signal to the control circuit 2'6 when a message signal is sent from the message assembly circuit 24. and a switch circuit connected to the terminal 10. When a call signal is sent, the input/output circuit 25 sends it as a signal a to the control circuit 26◇
The control circuit 26 receiving this signal sends a signal whose pulse rises at time P to the switch circuit 27 to connect the power source to the light emitting diode 4 and cause it to emit light. The transfer of the video signal and the operation of pattern matching are synchronized. At 9 time Q after a predetermined number of clock pulses of the signal C appear, the control circuit 26U stops generating the clock pulses, and causes the pulse of the signal S to fall to disconnect the light emitting diode 4 from the power source, thereby causing the light emitting diode 4 to emit light. stop. During this time, the video signal transfer and pattern matching are completed. Furthermore, from time Q, the measurement signal generation circuit 22.
At time RK, a predetermined time T has elapsed taking into account the calculation processing time in step 23, control time #! 26 is the message assembly circuit 2
4, a number of clock pulses having a predetermined period are generated equal to the length of the telegram signal (the number of bits). The message assembling circuit 24 includes a parallel-to-serial conversion circuit, and adds a predetermined fixed message signal to the signal d sent from the measurement signal generation circuit 22, 23 to form a message signal in a predetermined format. The signal is applied to the parallel input terminal of the parallel-to-serial conversion circuit, and is converted into serial telegram signals according to the clock pulse of the signal e, which are sequentially sent to the input/output circuit 25. The input/output circuit 25 transmits a serial telegram signal in a predetermined format that includes a measured value signal to an automatic meter reading device on the meter reading center side via the input/output terminal 10.

FIG. 5 shows the measurement signal generation circuit 22 in the circuit of FIG.
FIG. 2 is a block diagram showing a configuration example. Binary video signals for each display digit of the water meter display section sent from the video processing circuit 28 are sent to the pattern identification circuit 30, respectively. Of the two signal levels of the binary video signal, the side corresponding to the outline of the number in the display digit is made to correspond to the logical value "1", and the other side is made to correspond to the logical value "0". . This binary video signal is applied to each input terminal of ten AND gates 33 (some of which are not shown).

The other input terminal of each AND gate 33 has numbers “0” to
One type of standard pattern signal "9" is inputted from the standard pattern generation circuit 31 in synchronization with the binary video signal for each clock pulse. Standard pattern generation circuit 3
The standard patterns stored in 1 are numbers "0" to "
9", one pixel on the light-receiving surface of the light-receiving circuit 5 corresponds to one pixel, and the bit corresponding to the pixel including the inside of the outline of that number on the other side of the light-receiving surface is set to the logical value "1".
” and the bits corresponding to other pixels are set to logical value “0”.
” is arranged in the same bit order as the pixel order in the binary video signal, and the control circuit 26
One bit is read out for each clock pulse sent from the standard pattern signal. Each AND gate 33
#'i, a signal in which a pulse appears only when both the binary video signal and the standard pattern signal have a logical value of "1".
It is sent to the counter 34. Each counter 34 counts the pulses sent from the AND gate 33 and sends a count signal to the division circuit 35. On the other hand, the counter 32 counts the clock pulses, and when the predetermined number of pixels of the binary video gII signal is reached, generates a pulse and sends it to the division circuit 35 to execute the division. , the count value Mi of the counter 34 is the standard) (The numerical value Si divided by the numerical value Bi sent from the turn generation circuit 31 is sent from each division circuit 35 to the determination circuit 36 (however, I corresponds to the number "i") (i = 0.1, 2..., 9).The number Bi is the logical value "1" in the standard pattern of the number "i".
” indicates the slave device with the number of bits. If the number of pixels that have the logical value rlJ in the binary video signal is t-N, then when the binary video signal and the standard pattern signal are respectively expressed as vectors whose elements are logical values for each pixel and bit, Correlation coefficient C of these two vectors
i, that is, the similarity is Ci=Mi/ (Bi X −'
Fr'). The above numerical value 8 i
= M i / B i is proportional to the correlation coefficient Ci; 6.
This is a quantity indicating the degree of similarity between the binary turn signal and the standard turn signal. The determination circuit 36 compares the numerical values SO to S9 and determines that the number rjJ t2 indicated by the standard turn signal having the largest numerical value 8j, the BCD code generated by the evolved decimal code pattern identification circuit 30, and the message assembling circuit 24.
sent to.

The configuration of the measurement signal generation circuit 23 is similar to the measurement signal generation circuit 22 shown in FIG. In this case, the standard pattern is to make one pixel correspond to one bit for each of the numbers "0" to "9" attached to the display scale, and while the pointer is indicating that number, the inside of the outline of the pointer is It is assumed that the bit corresponding to the pixel containing 1# is set to a logical value "1" and the other bits are set to a logical value "0". Furthermore, since the value corresponding to the numerical value Bl is almost the same as the numerical value riJic, there is no practical problem even if the division circuit is omitted.

As explained above, the metering signal generation circuits 22 and 23 identify the numbers displayed by each digit of the display section of the water meter 1 shown in Fig. 81, and convert each number into BCD.
Send the signal d expressed as a code to the message assembly circuit 24. For example, in the case of the display shown in FIG.
,0100).

Since most of the electric circuit shown in FIG. 3 can be configured as a digital circuit, it is suitable for LSI integration, and a J-shaped meter sensor that can be installed above a water meter can be realized. Further, it is only necessary to emit light from the light source and read the measured value only when a call signal is received from the meter reading center, which has the advantage of requiring less power consumption during operation. Although the example shows the case of automatic meter reading of a water meter, the same operation can also be performed in the case of automatic meter reading of gas or electricity meter, and is not limited to this example. isn't it. Furthermore, it is clear that there is no problem even if the display part of the meter is only a digital display or only an analog display. The advantage d1 is that it is possible to realize a meter sensor that reads a measured value and generates an electrical signal indicating the measured value.

[Brief explanation of the drawing]

FIG. 1 is a top view showing the display section of a water meter, and FIGS. 2 and 3 each show an embodiment of the present invention.
Water meter, 2...Meter sensor, 3...
... Electric circuit, 4... Light source, 5, 6... Light receiving circuit, 7... Condensing lens, 8, 9... Objective lens, 10...・Input/output terminal, D1 to D3・
... Display digit, AI, A2 ... Display scale, 11.1
2... Pointer, 20.21. Waveform processing circuit, 22.
23...Measuring signal generation circuit, 24...
Telegram assembly circuit, 25... Input/output circuit, 26...
...Control circuit, 27...Switch circuit, 28°29...Video processing circuit. yryr diagram No. 4 closed 2ε Do b ′! 15 Seki

Claims (1)

[Claims] an imaging means having a light emitting section that emits light for illuminating a metering display section of the meter; and a light receiving section that generates a first electrical signal according to a pattern generated from reflected light from the metering display section; The image pattern is identified by comparing the first electrical signal with a plurality of electrical signals indicating standard nocturnals prepared in advance corresponding to each measurement value on the measurement display section, and the image pattern is identified. A signal generating means for transmitting a second electric signal indicating a measured value, and an output means for transmitting a response signal including the second electric signal in response to a call signal sent from an external device. A meter sensor featuring: