JPS5983013A - Liquid crystal display type digital multimeter - Google Patents

Abstract

PURPOSE:To obtain a compact, inexpensive product having excellent operability, by using a liquid crystal display body with 1/4 duty in a display device. CONSTITUTION:Common 1-4 signals 88-91 are inputted to common terminals 73-76, respectively. Segment signals 92 and 93 are inputted to segment terminals 80 and 81, respectively. In this case, a potential difference is not yielded between the common signals and the segment signals. Therefore, a 1/4 duty liquid crystal display body is turned OFF as shown by a display 94. Then segment signals 96 and 95 are inputted to the segment terminals 80 and 81, respectively. Then a potential difference is yielded between the common signals 88 and 90 and the segment signal 95, and segments 58 and 59 are lighted as shown by a display 27. Thereafter, segment signals 99 and 98 are inputted to the segment terminals 80 and 81, respectively. Then, a pattern 56 is turned ON, as shown by a display 100. Patterns of 43 can be displayed by the 7 segment signals, 4 mark signals, and the 4 common signals. Therefore, the compact, inexpensive product with excellent operability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display method for a digital multimeter (hereinafter referred to as IM 1s).

In the case of the static drive method shown in FIG. 5, which is a conventional drive method, a minus display 2. AC measurement display 3. Data bold display 4° Battery warning display 5. Simple resistance measurement display 6. Buzzer display7. Low power resistance measurement display 8. Temperature measurement display9. Micro unit display 1 (
], capacity measurement display 11 mm unit display J21. Current measurement display 13. Kilo unit display 14, 'fjΣ pressure measurement display 15. Meg unit display 16. Resistance measurement display 17, It
l" digit display 18. Point l-1!-), If" digit 20, point 21, Itl' digit display 2
2. Point 2: (Display Jf 10-digit display 24.)"E), the number of display terminals 10G is 44, so the crab mark shown in Fig. 1 of the embodiment of the present invention is displayed below the numerical display. In addition to this, the wiring space was also expanded, and the number of liquid crystal display surface areas 11 had to be increased.

Also, the μ duty is 6 whistles and Ivr, the same is 2.
The auto range mode 1.Display 1. Minus display 2. The AC measurement table ``p rj'I j:j[E
Data bold display 4. The battery notice display 5. f);] Easy resistance measurement display 6. Said buzzer display7. The low power resistance measurement display 8. The temperature measurement display 9. The microphone mouth position display HJ, the capacitance measurement display II, the millimeter unit display 12, the 1b-flow measurement display I:3.
The above-mentioned giro unit display 14. Said voltage measurement display J5. Said Meg n 1st place display 16. Said resistance measurement display 17. 3H for the above
I display 18° Point 19. Said 102 digit display 20
．． Point 21 above. ■01 digit display 22. When displaying the point l-23 and the LO' digit display ii
Since the number of display terminals is 2.1, an increase in the area of the liquid crystal display and the number of terminals 107 is unavoidable.

Table 1 shows the relationship between the liquid crystal display driving method and the number of display terminals. As you can see from Table 1, there are 44 lines in the static system and a book in the dedicated duty system.

% duty One type requires 15 wires.

In addition, as shown in Table 1, in the static type (Figure 5) and the single-duty type (Figure 6), the number of terminals is very large, so the terminals must be placed above and below the liquid crystal display, and the mounting pattern to the board is required. It required skill to attach and adjust the viewing angle.

On the other hand, since the number of terminals is very large, one-chip Aρ conversion LS
It is difficult to form a liquid crystal display drive circuit on the IW,
As shown in Figure 7, in addition to the Aμ converter LS1105, a liquid crystal display,
The driver gjIILs 104 is required.

Further, the conductive rubber that is a connecting part between the liquid crystal display and the substrate is required for a long time, and the cost is high, and the cost is greatly influenced by the number of terminals.

On the other hand, if the duty ratio is extremely increased, the display density of the liquid crystal display becomes high, but the clear viewing range is narrow and the display becomes very difficult to see.

Therefore, the cost of the DMM product increases, the mounting space increases, and the functionality deteriorates.

The present invention eliminates such drawbacks and provides a product that is compact, easy to operate, and reduces costs by improving the display ability of the DMM and reducing surface scraps and the number of YJ marks on the liquid crystal display. be.

The present invention will be explained in detail below with reference to the drawings.

FIG. 2 is an embodiment of a four-duty liquid crystal display according to the present invention.

Segment terminal 77 is segment 3], :32,
33, 72.

Segment terminal 78 connects segments 65 , 68 , 69
．． 70.

Segment terminal 79 segments (i4, 66, 6
7, 71.

Segment terminal 80 connects segments 57 , 60 , 61
, 62.

Segment terminal 81 connects segments 56 , 58 , 59
, 63 segment terminal 82 connects segments 49 , 52
, 53 , 54 segment terminal 83 is segment) 5
0, 51, 55 segment terminal 84 is segment 3
0, 34, 35, 36 segment terminals 85 are segment 37, 38, 39, 40 segment terminals 8
6 is the segment 41 , 43 , 45 , 47 segment terminal 87 is the segment 42 , 44 , 46 , 48
31. On the other hand, on the common side, the common 1 terminal 73 is a segment).
, L(4, 65, 66, 57, 58, 49, 50
, 39, 41, 42.

Common 2 terminal 74 connects segments 30 , 32 , 33
, 70, 71, 62, 63, 54, 55, 43, 44
, common 3 terminal 75 has segments 67 , 69 ,
59, 61, 51, 53, 45, 46, common 4 terminal 76ij, segment 72, 68, 64
, 60.

, 56, 52, 47, and 48, respectively. In the patterned liquid crystal display, the common 1 terminal 73. Common 2 terminal 74° Common 3 terminal 75. The display from the liquid crystal display when the liquid crystal drive signal in FIG. 3 is input to the common 4 terminal 7G and the segment terminal 80.81 is shown.

Now, common 1 terminal 73 to common 1 signal 88. Common 2 terminal 74 to Common 2 signal 89. Common 3 terminal 75 to common, 3 (W No. 90. Common 4 terminal to common 4 signal 91
is input, and the segment signal 92. is input to the segment terminal 80.
When the segment signal 93 is input to the segment terminal 81, there is no potential difference between the common signal and the segment signal, so the display turns off and appears as shown in the display 94.

Next, the segment signal 9-6 to the segment terminal 80. When the segment signal 95 is input to the segment terminal 81, the common 1 signal 88, the segment signal 95, and the common 3 signal 9 are input.
Since there is a potential difference between 0 and segment signal 95, segments 58 and 59 flicker, as shown in display 97.

Next, the segment terminal 80 is connected to the segment terminal number 99. When the segment signal 98 is input to the segment terminal 81, a potential difference is generated between the common 4 signal 91 and the segment signal 98, so the pattern 56 lights up and the display 100 appears. Now, when actually displaying, what is required is 8 segment II (2 segment terminals and 4 common terminals), and in the present invention, 43 patterns are used, as shown in Table 1, segment signals 7 It can be displayed with 4 main mark signals and 4 common signals, a total of 15 signals.Also, the liquid crystal display of the A duty is different from the liquid crystal display of the Akira duty, and contrast can be obtained, so there is no problem.

As described above, the present invention can provide a product that is small, has good operability, and is cost-reduced by improving the display ability of the DMM and reducing the area and number of terminals of the liquid crystal display.

In addition, because the number of terminals has been reduced, the liquid crystal drive circuit can be built into a single-chip eight-beta conversion LSI (102) as shown in Figure 4, resulting in extremely superior reliability, mass productivity, and improved operability. have an effect.

[Brief explanation of drawings]

FIG. 1 is a diagram of a liquid crystal display according to the present invention. l...Auto range mode display 2 fight・Fist minus display 3...AC measurement display 411...Data hold display 5 books...Battery warning display 6...Simple resistance measurement display 7・e・Buzzer display 8・...Low power resistance measurement display 9@...Temperature measurement display 10...Micro unit display 11...Capacitance measurement display 12...Millimeter display 13...Current measurement display 14...Kilometer unit display 15 ... Voltage measurement display 16 - Φ / Meg unit display 17 ... Resistance measurement display 18 ... 10 " Digit display 19 - Φ / Point addition - ... Ill " Digit display 21 ... Point 2211I1111O 1 digit display 23 + 1 ...Point U...-10' digit display Figure 2 is a common layout diagram of the liquid crystal display according to the present invention.
+ and segment wiring diagram (bl. FIG. 3 is a diagram of driving waveforms for the liquid crystal display according to the present invention. 88... Common L signal 89 @-Common 2 signal 90... Common 3 signal 91... Common 4 signal 92.93- -Segment signal 94...display 95.96...segment signal 97...display 98.99...segment signal 100e/display Fig. 4 is an embodiment according to the present invention. 101--Display of the present invention Duty liquid crystal display body 102・
・1-chip Aρ conversion L 81 FIG. 5 is an example of a conventional static type liquid crystal display. Figure 6 shows an example of a conventional single-duty liquid crystal display. FIG. 7 shows an embodiment using a conventional drive system. 103... Conventional liquid crystal display 104... Liquid crystal display driving LSI 105... ρ conversion LSI More than $/1! (Q-λ b3 82 圀94 F-1 9,3t-J/:. aro 64- $4 times

Claims (1)

[Claims] A liquid crystal display type digital multimeter characterized in that a liquid crystal display with a display section VC1, 4 Tutee is used in the digital multimeter.