JPH0674982B2 - Sensing method and apparatus for light emitting numeric display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for detecting a display change in a numerical display device by means of a luminous body.

[0002]

2. Description of the Related Art For example, a fare display meter for a taxi is required to display a fare that accurately corresponds to the traveling distance. Therefore, the fee display meter is periodically inspected by being driven by the drive device that rotates the mileage detection rotating portion. For this inspection, it is first necessary to detect that the display on the meter has changed, and the mileage is read at the time of this change. Conventionally, a person visually detects a display change of the meter, which is inefficient, and thus automation thereof has been desired.

Most of the display section of the charge display meter is composed of a seven or more segment type electronic display device. Therefore, for automation, it is conceivable to arrange an optical sensor at a position corresponding to each segment and detect the presence or absence of light emission of each segment. However, this requires a large number of photosensors according to the number of segments. Further, since there are various sizes and shapes of the display portion of the meter, in order to correspond to each segment, it is necessary to change the arrangement according to them or prepare different sizes, which is complicated. Is.

In addition to this, a lot of detections and evaluations such as environment and control state are made by the display change of the light emitting type numerical display portion, and it is very convenient if the display change can be appropriately automated.

The present invention has responded to such a demand, and has a relatively small number of photosensors, and a detection method for a light emitting type numerical display device which has a wide range of application to display parts of different sizes and shapes. And to provide a device.

[0006]

The above objects of the present invention are as follows:
A method for detecting a change in display in a light emitting numeric display device, wherein an optical sensor is arranged as an end sensor near the upper and lower ends of the numeric display area, and a central sensor is provided at the vertical center of the numeric display area. As the optical sensors, the end sensors and the central sensor are provided at intervals substantially corresponding to the left and right intervals of the numerical display area, and the intensity of light from the numerical display area is determined by these optical sensors in a predetermined cycle. Is repeatedly detected, and a first value is calculated as a difference in detection value between the central sensor located at or closest to the numerical display area and an end sensor adjacent to the central sensor, First
For the value of, the second value is calculated as the difference between the values before and after the repetition of the detection, and when the absolute value of the second value exceeds a predetermined value, it is determined that the display in the number display area has changed. A method for detecting a characteristic light-emitting numeric display device, and a device for detecting a change in display in the light-emitting numeric display device, wherein adjacent numeric display areas are provided in the vicinity of the upper and lower ends of the numeric display area. An end sensor which is an optical sensor arranged at an interval substantially corresponding to the left-right interval of
In the vertical center of the numeral display area, a central sensor, which is an optical sensor arranged at an interval substantially corresponding to the left-right distance between adjacent numeral display areas, and light from the numeral display area detected by these light sensors. As an output device that repeatedly outputs the intensity detection value of a predetermined period, and as a difference between the intensity detection values of the central sensor and the end sensor adjacent to the central sensor in the number display area or at a position closest thereto. A first calculation unit that calculates a first value, a second calculation unit that calculates a second value as a difference between the values before and after the repetition for the first value that is repeatedly calculated, and the second value And a set value are compared with each other to determine a change in the numerical display in the numerical display area.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to detection of a taxi fare display meter will be described below with reference to the accompanying drawings.

FIG. 1 shows three to four different number display areas 1A, 10A, 100A, 1000A, 1B, 10B, 100B, 1000B, 1C, 10C, 100C, and photosensors for them, in a light emitting type number display device. 1 to 8 are shown. Edge sensors 1, 2, 4, 5, near the upper and lower ends of the numerical display area
7 and 8 are arranged, and optical sensors 3 and 6 are arranged as central sensors in the vertical center of the numeral display area. The end sensor and the center sensor are provided alternately at intervals substantially corresponding to the left and right intervals of the numeral display area. The distance from the light emitting surface of the numerical display area to the sensor is appropriately determined depending on the directivity and sensitivity of the sensor. For example, the horizontal and vertical dimensions are 8 to 11 mm for a numerical display area of 8 mm × 11 mm to 10 mm × 15 mm. To be done. It should be noted that in this example, the first position (the rightmost digit) does not change at “0”, so no sensor is arranged. Further, since the thousandth digit can be sufficiently detected by the hundredth digit center sensor 6, the central digit sensor is not arranged in the thousandth digit display area.

FIG. 2 is a block diagram of the detection device. The detection value output device 20 is connected to the sensor unit 10 including the optical sensors 1 to 8. Detection value output device 2
0 detects whether the display system of the numerical display device is a dynamic display by sequentially blinking high cycle of each numerical display area or a static display of continuous lighting, and outputs according to this.

An illuminance difference calculator 30 is connected to the detected value output device 20 via an automatic gain adjusting device 21 for adjusting the output value. The digit timing generation unit 40 is connected to the output end of the illuminance difference calculation unit, and the calculated value output from the illuminance difference calculation unit is stored in the next calculated value storage unit 50 in association with the digit of the numeral. ing. A comparison unit 60 is connected to the output end of the calculated value storage unit 50. The output end of the comparison unit 60 is connected to the determination unit 70, and the determination unit 70 is connected to the display unit 71 and the control unit 72.

The case where the number display device is a dynamic display will be described. The detection value output device 20 outputs the detection value by each of the sensors 1 to 8 every time the number of each digit is turned on. This output value can be monitored as a waveform representing the illuminance change along the time axis. FIG. 3 is a graph showing output values corresponding to the sensors 1 to 8 when the numeral display device displays “480”, and FIG. 4 shows the case of “570” shown in the next display cycle. 7 is a graph showing a similar output value of FIG. The illuminance difference calculation unit 30 calculates the difference (first value: D) between the detection values of the center sensor and the end sensor that are output each time each number is turned on. That is, when the numeral of 1st place is lit, the difference between the central sensor 3 and the end sensor 1 of D (1st 3-1) [1st place] is shown. The same shall apply hereinafter. ], D (Ichi 3-2), D (Ichi 3-4), D
(Ichi 3-5), D (Ichi 6-4), D (Ichi 6-5), D
(Ichi 6-7), D (Ichi 6-8), ○ When the number of 2 picked up lights up, D (pick 3-1), D (pick 3
-2), D (pickup 3-4), D (pickup 3-5), D (pickup 6-
4), D (pickup 6-5), D (pickup 6-7), D (pickup 6-)
8), ○ D (hundred 3-1), D (hundred three)
-2), D (hundred 3-4), D (hundred 3-5), D (hundred 6-)
4), D (hundred 6-5), D (hundred 6-7), D (hundred 6-)
8), is calculated.

In this example, detection is performed only in the case of 3-digit display. In the case of 4-digit display, the same calculation is performed for the thousands digit. FIG. 5 shows the first value when the numerical display device displays “480”, and FIG. 6 shows the first value when the display “570” obtained in the next operation cycle. Is shown. The output of the illuminance difference calculation unit is sent to the digit timing generation unit 40, and the calculated value output from the illuminance difference calculation unit is stored in the next calculated value storage unit 50 in association with the digit of the numeral. . The output of the calculation value storage unit 50 is sent to the comparison unit 60, and each comparison unit calculates the difference between the adjacent first values in the detection cycle to obtain the second value T. That is, for the calculated value of four ranks, T (one 3-1) = D (one 3-1) (Tn) -D (one 3-
1) (Tn + 1) [D (pickup 3-1) (Tn), D (pickup 3-1) (Tn +
1) shows the calculated value D (pickup 3-1) before and after each detection cycle (Tn and Tn + 1). The same shall apply hereinafter. ] T (Ichi 3-2) = D (Ichi 3-2) (Tn) -D (Ichi 3-
2) (Tn + 1) ... T (Ichi 6-8) = D (I 6-8) (Tn) -D (I 6-
8) (Tn + 1) ○ Regarding the calculated value of 5 pick-ups, T (pick-up 3-1) = D (pick-up 3-1) (Tn) -D (pick-up 3-)
1) (Tn + 1) T (pickup 3-2) = D (pickup 3-2) (Tn) -D (pickup 3-2)
2) (Tn + 1) ... T (pickup 6-8) = D (pickup 6-8) (Tn) -D (pickup 6-)
8) (Tn + 1) ○ Regarding the calculated value of six hundreds, T (hundred 3-1) = D (hundred 3-1) (Tn) −D (hundred three−)
1) (Tn + 1) T (hundred 3-2) = D (hundred 3-2) (Tn) -D (hundred 3-)
2) (Tn + 1) ... T (hundred 6-8) = D (hundred 6-8) (Tn) -D (hundred 6-)
8) (Tn + 1) FIG. 7 shows, for each digit, the second value relating to the display values “480” and “570” described above. The output of the comparison unit 60 is sent to the determination unit 70. The determination unit 70 compares a preset reference value (for example, 10 mV) with the absolute value of the second value for each digit, and if any of the absolute values is larger than the reference value, displays the digit of that digit. It emits a signal indicating that the display on the device has changed. The signal is sent from the judging section to the display means 71 and displayed. Further, if necessary, the signal is also sent to the control unit, and processing corresponding to the change in display is performed. In the case of a taxi fare display meter, the mileage is read when the display is changed.

FIG. 8 and FIG.
An example is shown in which the digit display of digits is detected.
Here, output and calculation are also performed for each sensor when the thousands digit is turned on in the numerical display cycle of the dynamic display. FIG. 8 shows the output value corresponding to each sensor, and FIG. 9 shows the second value obtained in the same manner as described above.

When the numerical display device is a static display, the detection value output device 20 periodically outputs the detection value as a pulse signal based on the illuminance continuously detected in time. The illuminance difference calculation unit 30 calculates the difference (first value: D) between the detection values of the center sensor and the end sensor for each cycle. In the case of static display, since all the digits are lit at the same time, there is no data when the digit is lit for each digit as in the dynamic display. That is, the sensor output value, the first value, and the second value for each lighting digit shown in FIGS. 3 to 7 are graphs in which the values are arranged in the vertical axis direction at one location on the horizontal axis. As described above, the subsequent processing is the same as the case of the dynamic display, except that the data based on the entire lighting is used instead of each digit. However,
The dynamic display is more advantageous in terms of detection accuracy because the number of data used for detection is larger.

The present invention can be applied to various numerical display devices based on light emission, such as a segment type and a type using a numeric-shaped photoelectric tube.

[0016]

According to the present invention, it is possible to provide a detection method and device for a light emitting type numerical display device which has the following effects. That is, in the present invention, in the vicinity of the upper and lower end portions of the number display area and in the central portion in the vertical direction,
The optical sensors are arranged at intervals substantially corresponding to the left-right interval of the numeral display area. Then, the detection is performed by calculating a first value as a difference between the light intensity detection values of the central sensor and the end sensor adjacent to the central sensor, and measuring the first value before and after the repeated detection. Is calculated as the second value, and the absolute value of the second value is compared with the reference value. In general,
In many cases, the light emission intensity of the numerical display area varies greatly depending on the display device. On the other hand, in order to detect the display change, it is necessary to detect a slight change over time in the light emission intensity (actually, illuminance). Therefore, if the variation value is to be calculated directly from the detection value of the light emission intensity (illuminance) of the display device at each time, the range for calculation must be widened,
The resolution is reduced, and it is difficult to detect a minute illuminance difference. In the present invention, as described above, the illuminance difference (first value) of a plurality of sensors at each time is used for calculating the temporal variation value (the second value). Even if the difference greatly differs, the range for calculating the variation value can be made relatively narrow, whereby the resolution can be increased and accurate detection can be performed. Further, since the difference between the detection values (illuminance) of the optical sensors is calculated, the noise component common to each sensor can be removed, which is also advantageous in improving accuracy. Therefore, according to the present invention, it is possible to cover a wide detection area with a relatively small number of sensors, and as a result, the degree of freedom in positioning the detection device with respect to the numerical display device is large, and the positioning is easy, and various display devices are provided. It is advantageous in application to the above and prevention of detection error due to vibration.

[Brief description of drawings]

FIG. 1 is a front view showing an example of arrangement of an optical sensor of the present invention with respect to a numeral display area.

FIG. 2 is a block diagram of an example of a detection device according to the present invention.

FIG. 3 is a graph of output values of an optical sensor for one example of display.

FIG. 4 is a graph of output values of an optical sensor for another example of display.

FIG. 5 is a graph of a first value corresponding to the above example.

FIG. 6 is a graph of a first value corresponding to the other example.

FIG. 7 is a second value graph for the two examples.

FIG. 8 is a graph of output values of the optical sensor for still another example of the display.

FIG. 9 is a graph of the second value when it changes from the above example.

[Explanation of symbols]

 1, 2, 4, 5, 7, 8 End sensor 3, 6 Central sensor 10 Sensor unit 20 Detected value output device 21 Automatic gain adjustment device 30 Illuminance calculation unit 40 Digit timing generation unit 50 Calculated value storage unit 60 Comparison unit 70 determination unit 71 display means 72 control device

Claims (2)

[Claims] 1. A method for detecting a change in display in a light emitting numeric display device, wherein an optical sensor is arranged as an end sensor near the upper and lower ends of the numeric display area, and the vertical center of the numeric display area is provided. An optical sensor is arranged as a central sensor in the section, and the end sensor and the central sensor are provided at intervals substantially corresponding to the left and right intervals of the numeral display area. A first value as a difference between the detection values of the central sensor which is repeatedly detected by a sensor in a predetermined cycle and is located in the numerical display area or at a position closest to the numerical display area, and an end sensor which is adjacent to the central sensor. Is calculated and a second value is calculated as the difference between the values before and after the above-described detection repetition, and when the absolute value of the second value exceeds a predetermined value, the display in the numerical display area is Determine that it has changed A detection method for a light emitting type numerical display device, comprising: 2. A device for detecting a change in display in a light emitting type numerical display device, wherein the device is arranged in the vicinity of the upper and lower ends of the numerical display region at an interval substantially corresponding to a horizontal interval between adjacent numerical display regions. End sensor, which is an optical sensor, and a central sensor, which is an optical sensor disposed at an interval substantially corresponding to the horizontal interval between adjacent numeral display areas in the vertical center of the numeral display area, and these light sensors. An output device that repeatedly outputs the intensity detection value of the light from the numeral display area detected by the sensor in a predetermined cycle, the central sensor in the numeral display area or a position closest to this, and the central sensor adjacent to the central sensor. A first calculation unit that calculates a first value as the difference between the intensity detection values of the matching end sensors, and a second calculation unit that repeatedly calculates the first value as the difference between the values before and after the repetition.
Light emission, comprising: a second calculation unit for calculating the value of the second value; and a comparison unit for comparing the absolute value of the second value and the set value to determine a change in the number display in the number display area. Sensing device for digital numeral display.