JPS6333713B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a plurality of display screens that display the absolute values of two input signals alternately input through a changeover switch and their deviation values, forming a bar graph-like display surface. The present invention relates to a display device that displays a display by lighting up a number of light emitting elements corresponding to the input signal in a group of light emitting elements.

Conventionally, as a device for displaying or instructing the deviation value of two variables A and B, two indicators are used to individually display the absolute values, and the deviation value is read from the difference between the two indications. Alternatively, a method is known in which the difference between variables A and B is determined by an arithmetic device, and the calculated value is indicated using an indicator whose median value indicates a deviation value of zero.

However, since the former requires two indicators, it is generally more expensive and requires a larger installation area, while the latter has the disadvantage of not being able to display the absolute values of each of the variables A and B. .

Therefore, the present invention eliminates the above-mentioned drawbacks by making it possible to easily display not only the absolute values of the variables A and B, but also their deviation values and magnitude relationships using one display device. The purpose is to

According to the present invention, each absolute value of two input signals inputted alternately via a changeover switch and their deviation value are displayed in a bar graph form to display a plurality of light emitting lights. A display device that displays a display by lighting up a number of light emitting elements in an element group according to the input signal, the step switch being connected to one side of the light emitting element group and scanning the light emitting element group; an on/off switch connected to a common connection end of the element group to open and close power to the light emitting element group; a clock signal source for sequentially driving the step switch; and a counter for counting the clock signal; first and second comparators detecting the coincidence and magnitude of the output of the counter and the input signal alternately inputted via the changeover switch; At the same time, a time limit circuit that stops supplying a clock signal to the step forward switch for the certain period of time; a cycle counter that switches and operates the clock signal, and when the clock signal is counted a predetermined number of times with respect to the first input signal by the counter, the step of the clock signal is determined by the output from the first comparator. While the supply to the switch is stopped, the time limit circuit is operated to stop the operation of the step switch for a predetermined period of time, and when the predetermined period of time has elapsed, the supply of the clock signal to the step switch is restarted to start the step switch. When the count value of the clock signal exceeds a predetermined value while stepping the switch, the output from the second comparator opens the on/off switch and stops supplying power to the light emitting element group. In this state, the step switch is stepped to the end and then returned to perform scanning and display for the first input signal, while for the second input signal, the output of the cycle counter is This is achieved by operating the changeover switch and performing scanning and display of the light emitting element group while the output of the timer circuit is disabled.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a timing diagram showing the operation of the light emitting device in FIG. 1, and FIG. FIG. 4 is a state diagram showing the display state of the display screen.

In these figures, a plurality of light emitting elements L ₁ to _{L n}
One end of the switch S ₂ is connected to the common
The other end is connected to the power supply PS through the step switch S1, and the other end is grounded through the step switch _S1 . The step switch _S1 is driven by a clock pulse from the control circuit CU to scan the light emitting elements _L1 to _Ln and cause them to sequentially emit light. The number of light emitting elements that emit light at this time is determined by a switch S ₂ whose opening/closing is controlled by a control circuit CU.
determined by the closing time of Step switch S ₁
As shown in FIG. 2, scanning consists of a scan cycle A for a variable A and a scan cycle B for a variable B. In the first scan cycle A, all light emitting elements are turned on for nτ time. In the next scanning cycle B, all the light emitting elements are turned on for a time τ.

Here, in cycle A, the input signal is large enough to light up to light emitting element _L8 , and in cycle B, it is large enough to light up to light emitting element _L5 , and light emitting element _L8 is emitted for 3τ time. It shall be lit. The light emitting element L ₁ ~ which is driven and controlled in this way
If L _n is formed and displayed in a continuous bar graph as shown in FIG. 3, the result will be as shown in FIG. 3a, for example.

That is, the portion indicated by the vertical line is the brightest, and then the double hatching and the single hatching become darker in this order, and the non-lighted portions L ₉ to _{L n} are naturally the darkest. This means that in the first scan cycle A and the next scan cycle B, the light emitting elements L ₁ to L ₅
The on time of is 2τ, i.e. scan cycles A and B
A total of two scans are performed, once for each, and L ₆ to L ₇ are scanned only once, and the lighting time is τ, whereas L ₈ is 3τ, so Among the elements that emit light, they have the longest on time and are therefore the brightest, followed by L ₁ to L ₅ and then L ₆ to _{L 7.}
This is because it becomes like this.

Note that the lighting time or scanning period of the light emitting elements L ₁ to _{L n} shall be selected at an appropriate time so that they appear to be continuously lit by taking advantage of the afterimage effect in the human eye. .

In this way, the absolute value of a variable can be determined by the number of light-emitting elements or their position, and the deviation value between them can be determined by the number of light-emitting elements or the difference in their position. Since the brightness of the number or position differs depending on the number of times it is scanned, it can be easily identified from the difference in brightness.

The specific configuration and operation of the control circuit CU will be explained in more detail below.

Referring again to Figure 1, the clock signal source
Clock pulses from CLK are applied to step switch _S1 and counted by counter Z.

On the other hand, input signals I ₁ and I ₂ are applied to comparators V ₁ and V ₂ via changeover switch S ₅ . Comparator V ₁
compares the input signals I ₁ , I ₂ and the counting output from the counter Z, respectively, and outputs an output signal if they match, and the comparator V ₂ outputs an output signal when the counting output of the counter Z corresponds to the input signals I ₁ , I It emits a signal when it becomes larger than ₂ . The output of the comparator _V1 is given to the timer circuit ZG, which generates an output signal for a predetermined time (nτ or more) to open the switch _S4 ,
Stop supplying clock pulses to step switch _S1 . Cycle counter ZZ is counter Z
It is activated by the reset signal or overflow signal to invalidate the timed output from the timed circuit ZG, and at the same time operates the changeover switch _S5 to switch between the input signals _I1 and _I2 .

It is now assumed that switches S ₂ , S ₃ and S ₄ are each closed, and switch S ₅ is on the contact a side and receives input signal I ₁ . Also, the input signal
Assuming that the magnitude of _I1 is large enough to light up to light emitting element _L8 , comparator _V1 operates when counter Z counts eight clock pulses.
As a result, time limit circuit ZG operates and switch _S4
is opened for a certain period of time, and the sending of clock pulses to step switch _S1 is stopped. As a result, the step switch S ₁ has a contact connected to the light emitting element L ₈
C is stopped and held at _{the 8} position for a certain period of time, and the counter Z
stops its counting operation.

In addition, in order to ensure a clear display, that is, to clearly distinguish it from a light emitting element that is scanned twice and lit for 2τ, it is desirable that the time limit of the timer circuit be at least greater than 2τ. Therefore, here it is set to 3τ.

Now, after this time limit 3τ has elapsed, the time limit circuit ZG
There is no output from the switch S4 and the switch _S4 is closed again. As a result, the step switch _S1 receives the clock pulse and starts to step forward, but at this point the count value of the counter Z is larger than the input signal value, so the comparator _V2 operates and the switch _S2 Open the
Power to the light emitting elements L ₁ to _{L n} is cut off. Therefore, although the light emitting elements L ₉ to L _n are scanned, no display is performed. Thereafter, the step switch _S1 steps to the final contact point _Cn , and then returns to the starting position.

On the other hand, the counter Z is set according to the number of meters of light emitting elements, and when this value is exceeded, a reset signal is issued, so the step switch cannot be activated.
It detects that the scanning by _S1 is completed and sends a reset signal (overflow signal) to the cycle counter ZZ. The cycle counter ZZ is operated by the reset signal to open the switch _S3 and switch the switch _S5 to the contact b side, so that from now on, the display will be based on the input signal _I2 .

In this case, assume that the input signal I ₂ is large enough to light up the light emitting element L ₅ , for example, and the comparator V ₁ detects a match between the input signal I ₂ and the output value of the counter Z and sets the time limit. Even if the circuit ZG is driven, since the switch _S3 is opened this time, the supply of clock pulses to the step switch _S1 is not stopped, and therefore the light emitting elements _L1 to _Ln are activated for a certain period of time τ. It is scanned and only L ₁ to _{L 5} are displayed in the same manner as above.

Thereafter, in the same way as in the above case, the step switch is restored and counter Z issues a reset signal, and cycle counter ZZ operates again to close switch _S3 and switch _S5 to contact a. Switch to the side and repeat the same operation.

Note that the comparators V ₁ and V ₂ stop sending out signals when the counter Z is reset.

In this way, the absolute values and deviation values of the input signals I ₁ and I ₂ can be displayed.

In the above, the input signals I ₁ and I ₂ are connected to the light emitting elements L ₈ and L ₅ respectively.
We have explained the case where the input signal is large enough to display I ₁ > I ₂ , but if I ₁ < I _2
Of course _{, in} the _case where
An example of a case where the size is such that it is displayed is shown in Figure 2b.
and shown in FIG. 3b.

Further, in the above explanation, the input signal was a digital value, but when the input signal is an analog value, the following procedure is performed.

FIG. 4 is a block diagram showing another embodiment of the invention.

What is shown in this figure differs from what is shown in Figure 1 in that an analog-to-digital converter ADC is provided to convert the analog input signals I ₁ and I ₂ into digital signals, and a step switch is selected. The point that a decoder DE is provided to drive the selection switch S _{' 1} and the switch is replaced with the switch S _1' .
The basic configuration and functions are almost the same, except that S ₄ and S ₃ are replaced with AND circuit A and NAND circuit NA to form an electronic logic circuit.
Detailed explanation will be omitted.

In the above description, input signals are treated as general quantities, but it is convenient to use one of the input signals as a target value and the other as a measured value for use as an indicating section of an indicating controller.

Further, the cycle counter may be a simple flip-flop circuit.

As described above, according to the present invention, two quantities can be displayed on one display device, so the number of display devices can be reduced, and the difference and magnitude relationship between two quantities can be displayed on the same display device. This makes it extremely easy to read deviations and magnitude relationships.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a timing diagram showing the operation of the light emitting device shown in FIG. 1, and FIG. 3 is a block diagram showing the operation of the light emitting device shown in FIG. State diagram showing the state of the displayed display surface, No. 4
The figure is a block diagram showing another embodiment of the invention. Symbol explanation L ₁ - L _n ... light emitting element, PS ... power supply, C ₁ - C _n , a, b ... contact, S ₁ ... step switch, S ₁ ' ... selection switch, S ₂ - S ₅ ...Switch, CLK...Clock signal source, Z...Counter,
ZZ……cycle counter, ZG……time limit circuit,
V ₁ , V ₂ ... Comparator, ADC ... Analog-digital converter, A ... AND circuit, NA ... NAND circuit, DE ... Decoder, CU, CU′ ... Control circuit.

Claims (1)

[Claims] 1 The absolute values of two input signals alternately inputted via a changeover switch and their deviation values are displayed on a plurality of light emitting element groups forming a bar graph-like display surface, the number of which corresponds to the input signals. A display device that superimposes a display by lighting up the light emitting elements, the step switch being connected to one side of the light emitting element group and scanning the light emitting element group;
An on/off switch connected to a common connection end of the light emitting element group to turn on and off power to the light emitting element group, a clock signal source for sequentially driving the step switch, and a counter for counting the clock signal. and first and second comparators for detecting coincidence and magnitude between the output of the counter and the input signal alternately inputted via the changeover switch;
a time limit circuit that operates for a certain period of time according to the output of the comparator and stops supplying the clock signal to the step switch for the certain period of time; a cycle counter that switches and operates the changeover switch when the clock signal is disabled, and when the clock signal is counted a predetermined number of times with respect to the first input signal, the first comparison While stopping the supply of the clock signal to the step switch using the output from the device, the time limit circuit is operated to stop the operation of the step switch for a predetermined period of time, and when the predetermined period of time has elapsed, the clock signal is not supplied to the step switch. When the count value of the clock signal exceeds a predetermined value when restarting the supply of the clock signal and incrementing the step switch, the output from the second comparator opens the on/off switch. The supply of power to the light emitting element group is stopped, and in this state, the step switch is stepped to the end and then returned to perform scanning and display for the first input signal, while the second input signal In response to the signal, the changeover switch is operated according to the output of the cycle counter, and the light emitting element group is scanned while the output of the time limit circuit is disabled.
A display device characterized by displaying information.