JPS5828191Y2 - Display stabilizer in electronic digital display scales - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a display stabilizing device in an electronic digital display frame, which outputs a weight signal corresponding to the weight of an object to be weighed when it is placed on a scale.

Recently, electronic digital display frames have been widely used in place of mechanical scales, and these electronic digital display frames convert the amount of mechanical displacement corresponding to the weight of the object to be weighed into an electrical signal using an A-D converter. This type of converter has a slit chart with a large number of slits formed at regular intervals along the mechanical displacement direction, and the slit chart and light emitting element are arranged in a manner corresponding to the weight of the object to be weighed. move relatively,
Each time the light emitted from the light emitting element passes through each slit, a pulse signal is output, and the converter outputs a predetermined number of pulse signals corresponding to the weight, and this pulse signal is counted by a reversible counter. The weight is displayed digitally by sending the counted value (weight signal) directly to the display unit.

As mentioned above, when the object to be measured is placed on the pan of the electronic digital display frame, the slit chart moves, but just before it completely stops, the slit width changes over the edge of one slit on the slit chart. Fine vibrations may occur within the following range.

Alternatively, it may stop on the end of the slit, and in this case, the slit chart may similarly vibrate due to the influence of external vibrations or wind.

In such a case, the light may or may not pass through the slit each time, so the pulse signal may or may not be output, and the digital display on the display may flicker and be difficult to discern by the human eye. It has drawbacks such as being difficult to read and difficult to read.

This invention was developed in view of the above circumstances, and its purpose is that even if the slit chart vibrates finely before it almost stops, the digital display will not flicker at all and will remain stable at all times. It is an object of the present invention to provide a display stabilizing device in an electronic digital display frame capable of displaying images in a manner similar to that shown in FIG.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

1 in the figure is a weight detection section, and this weight detection section 1 includes an A-D converter consisting of a slit chart, a light emitting element, a light receiving element, etc.
It includes a reversible counter that counts the pulse signals output from the A-D converter, and the count value of the reversible counter is sent as a weight signal to the first input terminals of the delay circuit 2 and the comparison circuit 4.

Here, the configuration of the above A-D converter etc. will be briefly explained.
Two slit charts each having a large number of slits of the same shape are arranged parallel to each other so that the pulse signals obtained therefrom have a phase difference of %π, and a light source section is attached to the two slit charts. The light that passes through each slit on the two slit charts is received by a light receiving section composed of a phototransistor, etc., and converted into an electrical signal.Then, the waveform is further shaped into an appropriate size by a waveform shaper. Each pulse signal is further converted into a pulse signal corresponding to the weight of the object to be weighed, and then this pulse signal is counted by a reversible counter.

In electronic scales, when an object is placed on the pan of the weighing section, the slit chart moves in proportion to its weight, and a pulse signal is output in proportion to its mechanical displacement. be done.

The weight signal delayed for a predetermined time by the delay circuit 2 is sent to the latch circuit 3, but when a hold signal is output from the timer 5 to be described later and is sent to the latch circuit 3, this latch circuit 3 receives the weight signal. The latched weight signal is latched and held, and the latched weight signal is sent to the second input terminal of the comparator circuit 4, as well as to a display section, a calculation section (all not shown), etc.

When the timer 5 does not output a hold signal, a weight signal that changes sequentially is sent via the latch circuit 3 to the comparison circuit 4, the display section, and the calculation section.

However, in the calculation section, when the unit price of the object to be weighed is set on the scale by operating the numeric keypad, this unit price is multiplied by the weighed weight to calculate the price, and the weight, unit price,
The weight, unit price, price, etc. are displayed in the price display section.

The comparison circuit 4 compares the weight signal output from the weight detection section 1 with the weight signal delayed by the delay circuit 2 and further sent through the latch circuit 3, and determines that both weight signals (weight values) match. If so, it outputs a coincidence signal, sends this coincidence signal to the timer 5, and sets the timer 5.

Only when in this set state, the timer 5 outputs a hold signal that causes the latch circuit to perform a latching operation as described above, and at this time, the weight signal sent to the latch circuit is latched.

Although the set time of the timer 5 can be changed, this set time is set to be sufficiently longer than the delay time of the delay circuit 2.

For example, if the slit chart moves after placing an object to be weighed on the scale, and the slit chart has almost come to a standstill, it is still vibrating a little and the weight signal is increasing or decreasing around the weight signal. If the period is longer than the delay time of the delay circuit 2, a match signal is output from the comparison circuit 4, and at this time, the weight signal sent to the latch circuit 3 is latched, and the weight, unit price, and price are calculated based on this weight signal. etc. are displayed on the display to stabilize the display.

Next, to explain the operation of the above embodiment, when the power is turned on to the scale and the scale is completely stationary without any external vibration before an object to be weighed is placed on it, the zero point of the slit chart is detected and the weight is detected. A weight signal "0" is output from the unit 1 and sent to the delay circuit 2 and the comparison circuit 4.

After a predetermined delay time has elapsed, the weight signal "0" is sent to the comparator circuit 4 via the latch circuit 3. At this time, both weight signals "0" are compared and a matching signal is output from the comparator circuit 4. The signal is sent to the timer 5, and the timer 5 is set.

Therefore, the timer 5 outputs a hold signal and sends it to the latch circuit 3, and the latch circuit 3 holds the weight signal rOJ until the object to be weighed is placed on the scale, and sends this weight signal "0" to the display section. Weight “0” i is displayed.

Even if the timer 5 times up, if the scale is completely stationary, the coincidence signal will continue to be output, so it will be set again, the latch circuit 3 will continue to latch the weight signal "0", and the display will show the weight "0". ”1 continues to be displayed.

Next, when a weight of, for example, 1002 is placed on the scale, the slit chart moves in the forward direction, and the weight signal output from the weight detection section 1 increases in proportion to the movement of the slit chart.

When the weight signal becomes "1", it does not match the weight signal "0" latched by the latch circuit 3, and the comparison circuit 4 no longer outputs a matching signal, but at this time, even before the timer 5 times up. A hold signal is output until the cigarette timer 5 times up, and the latch circuit 3 latches the weight signal "0" and the weight "0" v
is displayed.

When the timer 5 times up and is reset, the hold signal is no longer output and the latch circuit 3 stops the latch operation.

At this time, the weight signal output from the delay circuit 2, for example, "
10'' and subsequent ones are sent via the latch circuit 3 to the display section, arithmetic section, and comparison circuit 4.

The display shows the weight as “I OJ P, [IJ y, . . .
... will be displayed sequentially, and if a unit price has already been set on the scale, the calculation section will perform calculations to calculate the price etc. based on the weight signals sent sequentially, and the price display section of the display section will be displayed. Is displayed.

Also, during this period, of course, the comparison circuit 4 does not output a coincidence signal, so the timer 5 is not set.

Once the weight signal [00J is detected, the scale gradually approaches the stopped state and begins to vibrate between the weight signals "99" and "101", and the vibration period becomes longer and the weight signal is output from the weight detection section 1. [00J and the weight signal 1'-100J, which was first output from the weight detection section 1, delayed for a predetermined time by the delay circuit 2, and passed through the latch circuit 3, are simultaneously sent to the comparison circuit 4. Immediately, the coincidence signal is output, the timer 5 is set, and the hold signal begins to be output, so the latch circuit 3 latches the weight signal "100" at that time.

As a result, the weight "100 Jf?" is displayed on the display section which had been flickering along with the vibration of the scale, and the calculated price etc. are also displayed.

Furthermore, even if the weight signal still oscillates between "99" and "101" even after the coincidence signal is output after weighing the object as described above, the timer 5's setting time is longer than the vibration period of the scale. Since it is selected for a long time, the hold signal continues to be output, and the display content on the display section does not change after the coincidence signal is output once after weighing the object to be weighed, so that the display is reliably stabilized.

Also, even if the slit chart vibrates finely within the slit width after the weight signal "100" is detected, or if the slit chart stops with the light shining on the end of the slit, the timer 5 will time out in the same way. Until then, the display contents on the display section will not change.

When the object to be weighed is removed from the scale, the slit chart starts to move in the negative direction, but if the scale has stopped completely before the object is removed, the timer 5 is operating.
After the time has elapsed and the hold signal is no longer output, a weight signal, for example a weight signal of "40" or less, begins to be displayed on the weight display section of the display section.

Then, after the vicinity of the zero point of the slit chart begins to be detected continuously, when a coincidence signal is output from the comparison circuit 4, the timer 5 is set, the weight signal "0" is latched by the latch circuit, and the weight display section From now on, the weight "0" v will continue to be displayed.

As explained in detail above, the present invention uses a display stabilizing device in an electronic digital display rod to delay the weight signal output from the weight detection section of the scale by a predetermined time and output it.
When a hold signal is supplied, the delay latch circuit that latches the weight signal compares the weight signal output from the weight detection section with the signal output from the delay latch circuit, and when both signals match. a comparison circuit that outputs a match signal; and a timer that is set to a set state by the match signal output from the comparison circuit, generates the hold signal for a preset time, and supplies the hold signal to the delay latch circuit. For example, when an object to be weighed is placed on the scale and the scale comes to a near-stop state and a match signal is output from the comparator circuit, the timer is set and the latch circuit is activated at least during the set time of this timer. latches and holds the weight signal when the coincidence signal is output, so even if the scale vibrates unstably during this period, the display contents on the display section do not change and a stable display is always obtained.

That is, according to the present invention, display stability can be achieved both when there is no load and when there is a load.

[Brief explanation of the drawing]

The drawing is a circuit configuration diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Weight detection part, 2... Delay circuit, 3... Latch circuit, 4... Comparison circuit, 5... Timer.

Claims (1)

[Scope of utility model registration request] When an object to be weighed is placed on the scale, a weight signal corresponding to the weight of the object to be weighed is output from the weight detection section.In the electronic digital display frame, the weight signal output from the weight detection section is displayed. a delay latch circuit that outputs the weight signal with a predetermined time delay and latches the weight signal when a hold signal is supplied; a weight signal output from the weight detection section and a signal output from the delay latch circuit; and a comparison circuit that outputs a match signal when both signals match; and a comparison circuit that is set to a set state by the match signal output from the comparison circuit and generates the hold signal for a preset time; A display stabilizing device in an electronic digital display frame, characterized in that it comprises a timer supplying the delay latch circuit.