JPS638411B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scale that digitally displays weight values, etc., and a method for checking the display section of a weighing machine that displays a set unit price and the price of an object to be weighed, such as a fee scale.

The display section includes a multi-digit display and a driver circuit that drives the display according to an input signal. Conventionally, this type of display check was simply a lamp test condition in which all segments of all digits of the display were forced to light up regardless of the input signal, and it was simply a matter of checking whether any segments were missing. Since this checking method is insufficient in the following points, it is difficult to avoid an abnormal situation where an incorrect display is read.

(1) Since this is a lamp test of the display unit itself, it is not possible to check that each segment lights up individually.

(2) Unable to check brightness unevenness in segments.

Therefore, the present invention proposes a display section checking method that can eliminate the above-mentioned drawbacks.

The method for checking a display unit according to the present invention includes checking a multi-digit segment type display that constitutes a display unit.
One of the digits is set to a state in which specific check characters of a predetermined type can be displayed sequentially, and when the input of the check signal corresponding to the check character of the predetermined type is completed in order to display the check characters sequentially, one of the remaining digits is The present invention is characterized in that any one of the above is brought into a state in which a specific check character of a predetermined type can be sequentially displayed, and all digits of the display section are sequentially brought into a state in which the specific check character is displayed. The checking method will be explained based on an example.

Figure 1 shows the display peripheral circuit of a weighing machine equipped with a display check circuit, where segment-type displays D _P1 , D _P2 , D _P3 , and D _P4 are ring counters.
Dynamic pulses P ₁ to _{P 4} sequentially output by CNT ₁
It is dynamically driven by.
D _G is weight value data transmitted from the load converter (not shown), including first data d ₁ to be sent to the first digit display D _P1 and second digit display D _P2 and 3. It is composed of second, third, and fourth data d ₂ , d ₃ , and d ₄ to be sent to the digit display device D _P3 and the fourth digit display device D _P4 , respectively. MPX is a ring counter
The code signal CO ₁ output by CNT ₁ causes the first to fourth data of the weight value data _DG to be output at the timing when the dynamic pulses P ₁ to P ₄ are output.
A data multiplexer that sequentially outputs _d1 to _d4 ,
OSC ₁ is an oscillator that repeatedly outputs a pulse signal CL at a predetermined period, and F is a code signal that is sequentially switched each time the pulse signal CL is input and corresponds to 10 types of check characters from "0" to "9". (CO ₂ ), J is a coincidence detection section that detects when the code signal CO ₂ reaches "9," and K is a counter that counts the number of times the coincidence detection section J detects a coincidence. , the output lines l ₁ , l 2 , l 3 , l 4 are alternatively inverted to, for example, logic level “H” when the count values are “1”, “ ₂ ”, _“3 ”, and “ ₄ ”. M is an input data selection unit which outputs the data multiplexer MPX output in place of the code signal CO ₂ when the output line l ₄ of the counter K is inverted to logic level “H”. N is a decoder that converts the input data selection section M output into a code suitable for the display, and O is a dynamic pulse _P1 that selects the display devices D _P1 to D _P4 using the output lines _l1 to _l4 of the counter K as a control signal. A program section that controls the passage of dynamic pulses P _{3 , P 4 , and P 1 when output lines l 1 , l 2 , l 3} , and l ₄ are all at logic level "L". and when the output line _l1 is alternatively inverted to the logic level "H", it blocks the passage of the dynamic pulses _P4 , _P2 , _P1 ;
If the output line _l2 is alternatively inverted to the logic level "H", it blocks the passage of the dynamic pulses _P4 , _P3 , _P1 , and if the output line _l3 is inverted to the logic level "H", the pulse _P4 is blocked. , _P3 , and _P2 , and when the output line _l4 is inverted to logic level "H", the dynamic pulses _P4 to _P1 are allowed to pass through as they are.

It is assumed that the coincidence detection section J ends the coincidence detection when the output line _l4 is inverted to the logic level "H", and does not detect the code signal _CO2 even if it reaches "9".

Next, assuming that the check device shown in FIG. 1 starts operating immediately after power is turned on, its operation is shown in FIG.
The explanation will be based on ~i.

When the power switch (not shown) of the weighing machine is turned on at time _t1 , since the contents of counter K are "0", all output lines _l1 to _l4 become logic level "L", and program O becomes dynamic. Only the pulse _P4 is allowed to pass, and only the display device D _P4 [FIG. 2f] is in a displayable state. [Period] Also, the specific signal generating section F first outputs "0" as the code signal CO ₂ [FIG. 2c] via the input data selecting section M and the decoder N to the displays D _P1 to D _P4 . However, ring counter CNT ₁ is dynamic pulse P ₁ ~ _{P 4}
During the output period, the dynamic pulses P ₃ , P ₂ , and P ₁ are blocked by the program section O as described above, so that "0" is digitally displayed only on the display D _P4 . Next, each time the clock signal CL of the oscillator OSC ₁ is generated, the code signal CO ₂ of the output of the specific signal generator F is sequentially switched, and the display
“1”, “2”, “3”…”9” is displayed on D _P4 .
When the code signal CO ₂ reaches "9", the coincidence detection section J [Fig. 2 d] detects a coincidence, and the code signal CO ₂
At time _t2 when the value changes from "9" to "0", the count content of the counter K changes from "0" to "1", and the output line _l1 is inverted to the logic level "H". time
During the period () from _t1 to time _t2 , the checking period of the display device D _P4 ends, and the period moves on to the checking period () of the display device D _P3 . Output line _l1 is logic level “H”
When the display is reversed to , only the display D _P3 [Fig. 2 g] can be displayed instead of the display D _P4 , and the display D _P3
is an indicator of the period () according to the code signal CO ₂
D Displays “0” to “9” in sequence like _P4 .
Similarly, in periods () and (), only the display device D _P2 [Fig. 2 h] and the display device D _P1 [Fig. 2 i] are checked as being able to display. When the period () ends at time _t3 , the counter K
Since the output line _l4 of is inverted to the logic level "H" and the coincidence detection of the coincidence detection part J is prohibited, after time _t3 , the program part O outputs the dynamic pulses _P4 to
It does not prevent the passage of P ₁ . Furthermore, when the output line _l4 is inverted to the logic level "H", the input data switching section M automatically outputs the weighed value data D _G [Fig. ₂ e] of the data multiplexer MPX output instead of the code signal CO2. Therefore, display device D _P1 ~ _{D P4}
The weighing value will be displayed digitally instead of the check mark. The period at which ring counter CNT ₁ outputs dynamic pulses P ₁ to _{P 4} is 10 ^-3 seconds.
The period of the clock signal CL is on the order of several seconds.

Because it operates in this way, the operator can check whether the characters "0" to "9" are clearly displayed on the displays D _P4 to D _P1 in sequence during periods () to (). can.

In the above embodiment, there are ten types of specific check characters from "0" to "9", but the present invention is not limited thereto. Further, in the above embodiment, the check device is configured to automatically operate immediately after power is turned on, but it is also possible to operate it at an arbitrary time.

As explained above, according to the checking method of the present invention, the following effects can be obtained.

(a) Since all the digits forming the display section do not display check characters at the same time, the occurrence of misreading is reduced.

(b) Since it is possible to check for defects in the display section, it is possible to prevent erroneous weight values from being displayed.

[Brief explanation of the drawing]

FIG. 1 is a peripheral circuit diagram of a display section for explaining the checking method according to the present invention, and FIGS. 2 a to 2 i are waveform diagrams of essential parts of FIG. 1. D _P1 to D _P4 ... Display, OSC ₁ ... Oscillator, F...
...Specific signal generation section, J...Coincidence detection section, K...Counter, O...Program section.

Claims (1)

[Claims] 1. Set any one digit of the multi-digit segment type display that constitutes the display section to a state where specific check characters of a predetermined type can be displayed in sequence, and set the check characters to the check characters of the predetermined type in order to display the check characters in sequence. When the input of the corresponding check signal is completed, any one of the remaining digits is set to a state where a predetermined type of specific check character can be sequentially displayed,
A method for checking a display section of a weighing machine, characterized by sequentially setting all digits of the display section to a specific check character display state.