JPH02297017A - Display device - Google Patents

Abstract

PURPOSE:To execute read of a large number of significant digits at a low cost by displaying the part exceeding a range of resolution by a state being different from the part of a range of resolution, in the case the part of a range of resolution of a % value is not fluctuated for a prescribed time. CONSTITUTION:On the right side of an indicator (101 pieces of LEDs are provided in a line) 2, numerals of 0, 0.1 - 0.9 are graduated at every 10 pieces of LEDs. A CPU calculates how many % of a full scale an input signal from an A/D converter becomes. For instance, it is set to 93.1%. In the case an integer part 93% is not fluctuated while T seconds go back to the past from the present, as for a selecting signal, in the case of dynamic turn-on, a pulse is outputted successively to LEDs L0 - L93 of '0' through 93. As for a pulse of the LED L10 corresponding to the scale 0.1, its time width becomes larger than the pulses of other LEDs L0 - L9, L11 - L93 at every 1 frame. Accordingly, the LEDs L0 - L8, L11 - L93 are turned on by ordinary luminance, but only the LED L10 is turned on alternately by high luminance and ordinary luminance. Also, in the case the integer part 93% is fluctuated during T seconds, only the LEDs L0 - L93 are turned on by ordinary luminance.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to a bar graph type display device.

(b) Prior Art When monitoring the state quantities of a plant in process control, for example, a moving coil type or bar graph type display device is used as a device for analog displaying the state quantities.

A moving coil type display device is composed of a moving coil, a pointer, a scale plate, etc., and the position of the pointer is read by the scale plate to know the state quantity. However, since this moving coil type display device includes a mechanism called a moving coil, its response speed is slow, it is susceptible to the influence of surrounding magnetism, and its installation angle is also limited.

On the other hand, a bar graph type display device is a display device constructed by arranging N display elements (elements) in a bar (band) shape, such as a light emitting diode (LED), a liquid crystal display (L,
CD), fluorescent tube display, plasma display, display, etc. are used. Since the bar graph type display device does not have any mechanical elements, it has a fast response speed, is not easily affected by surrounding magnetism, can be installed at any angle, and has excellent visibility.

(c) Problems to be Solved by the Invention The resolution of the above bar graph display device is proportional to the number N of elements of the display device. Therefore, if the number N of elements cannot be set sufficiently due to restrictions such as the overall length of the display, reading with a large number of effective digits cannot be performed. Therefore, a 7-segment type numeric display is also installed, but this increases the cost and requires movement of the viewpoint when reading.

The present invention has been made in view of the above, and aims to provide a display device that is capable of reading a large number of effective digits at low cost and does not require movement of the viewpoint.

(d) Means for Solving the Problems In order to solve the above problems, the display device of the present invention includes a display device including a plurality of display elements arranged in a row, and an input signal that is within the full scale of the display device. %, and a display driving means for displaying the % value calculated by the % value calculating means on the display within the resolution range of the display, a fluctuation determining means for determining whether or not a portion within the resolution range of the % value does not fluctuate for a certain period of time; and when the fluctuation determining means determines that the fluctuation is small, the range of the resolution of the % value is exceeded. The present invention is characterized by comprising second display driving means for causing the display to display the portion in a manner different from the portion within the resolution range of the % value.

(e) Effect: In the display device of the present invention, a portion within the resolution range and a portion exceeding the resolution range are displayed in different manners on one display, and significant digits can be read without providing a separate display. increasing the number.

Furthermore, since both are displayed on the same display, there is no need to move the viewpoint during reading.

When the fluctuations in the input signal are large, displaying a part that exceeds the resolution range makes the display difficult to see and there is a high risk of misreading. The portion that exceeds the range will be displayed.

(f) Example An embodiment of the present invention will be described below based on the drawings.

FIG. 2 is a block diagram illustrating the circuit configuration of the embodiment display device. 3 is an analog/digital (A/D) converter that converts an analog input signal into a digital signal. From this A/D converter 3, an input signal that has been digitally converted at a predetermined sampling period is taken into the CPU 4.

The CPU 4 has a function of calculating what percentage of the full scale this input signal corresponds to, a function of determining whether the integer part of this percentage value fluctuates within T seconds, and the like.

The lighting control signal from the CPU 4 is output to the decoder 5, and the decoder 5 converts it into a selection signal for each element and sends it to the LED drivers 6-0 to 6-5°. It is output to.

The LED display 2 has 101 LEDs in this embodiment.
DL o~LIG. are arranged in a row, and one LED corresponds to a second element (display element). Each LEDL, ~L1°. are the corresponding LE
D drivers 6-0 to 6-Io. The lighting is driven by.

On the left side of display 2, 0, 0, and 0 for each LEDIO are displayed.
IOl..., the numbers 90,100 are graduated [
See Figure 1(a)]. Also, on the right side of the display 2, Olo, 1, ..., 0 is displayed for each LEDIO.
．． The number 9 is marked on the scale.

Next, the operation of the embodiment display device will be explained. First, the CPU 4 takes in a digitally converted input signal from the A/D converter 3 (step (hereinafter referred to as ST), see FIG. 3).

The CPU 4 calculates what percentage of the full scale this input signal is (Sr1).

Now, assuming that the value of this % is p, it will be described as follows for convenience of explanation.

p-n+0.1m n is an integer from 0 to 100, and m is an integer from 0 to 9. That is, n represents the integer part of p (%), which corresponds to the resolution of the display 2. Furthermore, 0.1 m represents the one digit below the decimal point of p (%), which conventionally could not be displayed as it exceeds the resolution range of the display 2.

In Sr1, it is determined whether or not n has changed during T seconds before the present time. If this judgment is YES, branch to Sr1, and the integer part n and 1 digit after the decimal point are 0.1.
m is displayed on the display 2. Now if p = 93.1%,
In the case of dynamic lighting, the selection signal becomes as shown in FIG. 4, and pulses are sequentially output to LEDLs 0 to 93 and 1 to L0. At this time, L corresponding to scale 0.1
E.D.L.

The pulses of the other LEDs LO~L9,L every frame
The time width is larger than that of pulses II to L91. Therefore, as shown in FIG. 1(a), LEDLO~
L9 % Lll to L93 (shown with diagonal lines) are LEDL, although they are lit at normal brightness. Only the light will be lit alternately between high brightness (shown in black) and normal brightness.

On the other hand, if the determination of Sr1 is NO, branch to Sr1,
As before, only the integer part of p is displayed.

For example, if the integer part of P is 93, LEDL0~
Light up L and 3 at normal brightness. When the processing of ST'4 or Sr1 is completed, the process returns to STI again.

The reason why one decimal place is displayed only when n is stable for T seconds or more in S73 is that if one decimal place is displayed when n fluctuates greatly, the display becomes difficult to read and there is a high risk of misreading. It is from.

FIG. 1(b) shows the display 2 in the case of p=9.1%. In this case, LEDL, ~L, is lit at normal brightness, and LEDL,. repeats high brightness and complete off. Moreover, FIG. 1(C) shows the case where p=10.1%, and in this case, LED, .about.L.

lights up at normal brightness, and L E D L la repeats lighting at high brightness and normal brightness.

FIG. 1(d) shows a modified example of the display, in which the scale below the decimal point is concentrated at the lower end of the display 2,
LEDL to L8 are used to display the decimal point. Of course, the scale below the decimal point can also be concentrated on the upper end of the display 2.

FIGS. 1(e) and 1(f) further show modified examples of display, where the integer part n of p is L 1%-1% Lfi , Lr
+41 is displayed by lighting three LEDs, and 0.1m below the decimal point of P is to blink L++1m.

Figure 1(e) shows the case when p=93.1%,
Lqz, L93, and L94 are lit, and LIO is blinking. In addition, in FIG. 1(f), p = 9.1%
In this case, Ls and L9 are lit, and Llo is blinking, so that even if the display of the integer part and the display of one digit below the decimal point overlap, there is no problem in reading.

In the above embodiment, the number of elements is 100, the unit is %, and the integer part of P and one digit after the decimal point are displayed. However, the present invention is not limited to this, and the design can be changed as appropriate. It is possible.

In addition, the display device is not limited to LED, but also LC.
D. The design can be changed as appropriate, such as a fluorescent tube display or a plasma display.

(g) As described in detail of the invention, the display device of the present invention includes a fluctuation determining means for determining whether or not a portion within the resolution range of the % value fluctuates over a certain period of time, and this fluctuation determining means. and second display driving means for displaying a portion exceeding the resolution range of the % value on the display in a manner different from that of the portion within the resolution range of the % value when it is determined that the variation is small. This feature has the advantage that the number of valid digits that can be read can be increased without significantly increasing the cost, and there is no need to move the viewpoint during reading.

[Brief explanation of drawings]

1(a), 1(a) and 1(c) are diagrams illustrating display examples of a display device according to an embodiment of the present invention, FIG. 1(d), and 1(c), respectively. (e) and FIG. 1(f) are diagrams each explaining a modified example of the display of the same display device, and FIG. 2 is a block diagram explaining the circuit configuration of the same display device.
FIG. 3 is a flow diagram explaining the operation of the display device;
The figure is a diagram showing an example of a selection signal of the same display device. 2: Display, 4: CPU. 5: Decoder, 6: LED driver. Figure (d) Figure (e) Figure (f) Figure

Claims (1)

[Claims] (1) A display device comprising a plurality of display elements arranged in a row, a percentage value calculation means for calculating what percentage of the full scale of the input signal corresponds to the display device, and a percentage value calculation means calculated by the percentage value calculation means. In a display device comprising a display driving means for displaying a percentage value on the display device within a resolution range of the display device, the display device is configured to determine whether or not a portion within the resolution range of the percentage value has not fluctuated for a certain period of time. a variation determining means for determining, and when the variation determining means determines that the fluctuation is small, displaying the portion exceeding the resolution range of the % value on the display in a manner different from the portion within the resolution range of the % value; A display device comprising: second display drive means for displaying a display.