JPS5827505B2 - display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device using a field effect liquid crystal (hereinafter referred to as FEM liquid crystal), and particularly to a display device suitable for notifying a drop in display drive voltage.

Digital devices such as calculators are limited to a certain voltage range in which they can operate normally, and if the power supply voltage drops, arithmetic operations and lead-in operations will malfunction.

Especially in the case of devices used for calculations such as calculators, if you use the device without knowing that the battery capacity has run out,
This will lead to errors in the calculation results and serious consequences.

For this reason, calculators and the like employ a method of notifying the operator of the drop in power supply voltage by turning off the numerical display or lighting up the decimal points of all digits when the power supply voltage falls below a specified value.

However, the above-mentioned method has the disadvantage that it is necessary to add to the internal circuit a power supply voltage detection means and a means for causing a numerical display to display a specific display based on the output of this detection means.

In particular, the detection means must constantly detect the power supply voltage.
Power consumption in this method is also a big problem.

That is, calculators and the like that are made of a display body using FEM liquid crystal and an LSI having a C-MOS configuration have extremely low power consumption and can be operated for hundreds of hours with a single mercury battery.

When the above-described detection means is added to the above-mentioned calculator, the power consumption of the detection means is comparable to that of the LSI and the display, and there is a drawback that the battery life is halved.

The present invention has been made in order to solve the above-mentioned drawbacks all at once, and utilizes the characteristics of a display using FEM liquid crystal to notify a decrease in driving voltage.

That is, the present invention utilizes the viewing angle decreasing characteristic of the FEM liquid crystal display to notify a decrease in driving voltage.

The above viewing angle reduction characteristic will be explained with reference to FIGS. 1 and 2.

FIG. 1 is a simplified cross-sectional view of a reflective display using FEM liquid crystal (hereinafter referred to as display panel 1), and 2 and 3 are FEM liquid crystals.
A transparent conductive film having a desired shape is provided on the inner surface of a transparent substrate made of glass or the like with an EM liquid crystal 4 interposed therebetween.

5 is a spacer for keeping the distance between the substrates 2 and 3 constant and for enclosing the liquid crystal 4 therein.

Polarizing plates 6 and 7 are provided on the outer surfaces of both the substrates 2 and 3, and their polarization directions are different from each other by 90°.

8 is a reflecting plate made of an aluminum plate, a stainless steel plate, or the like.

9 is a protective filter for protecting the liquid crystal, the substrate, etc.

The display panel as described above can display a desired shape by applying a predetermined drive voltage V between the FEM liquid crystals 4.

For example, if the shape of the transparent conductive film is appropriately formed, it is possible to display a segment in the shape of a ``date'' as shown in Figure 2, and if this segment is selected appropriately, the numbers ``O'' to ``U'' can be displayed.
9I+ can be displayed.

In the figure, reference numeral 10 denotes a battery alarm segment, which will be described in detail later.

In addition, in FIG. 1, the liquid crystal of this segment 100 portion is represented by a polka dot pattern.

In the display panel 1 as described above, when a driving voltage is applied, the alignment of the liquid crystal molecules changes to produce an optical effect and a segment appears, but this display has directionality.

In other words, even if a specified voltage is applied, the display can only be seen from a range of B degrees in front of the normal A and A degrees on the far side, and cannot be seen from any other angle. It has characteristics.

The value of AB above is generally around B-45°, A-100
Although it is said to be around the same value, the value varies depending on the type of liquid crystal and other conditions.

Therefore, the viewer views the display from the viewing angle range A0B0 (ie, the range from mouth to part C) with respect to the display panel 1.

However, in the display panel 1, as the driving voltage decreases, the viewing angle range in which the display can be seen changes.

That is, as the driving voltage decreases, the viewing angle of the display also decreases.
It gradually decreases from C0 to Do.

Specifically, even if the voltage decreases, the overall directivity angle (A-1-Bo) hardly changes, but the viewing angle decreases as a whole.

Therefore, for example, when the driving voltage drops by 10% from the specified value, the range in which the segments 10 are visible shifts from 1 to 2 to 2, and the segments 10 become invisible in other areas, for example, from 1 to 2.

Similarly, when the drive voltage drops by 20% from the specified value, the lowest position moves to E.

The above characteristics are referred to as display panel drive voltage-viewing angle characteristics (abbreviated to viewing angle reduction characteristics).

The present invention takes advantage of the above-mentioned characteristics, by instructing the display section to lower the viewing angle to the lower limit voltage for normal operation, and by utilizing the fact that the viewing position of the FEM liquid crystal approaches the indicated point, the drive voltage is lowered. It is designed to notify you.

Hereinafter, specific examples of the present invention will be described with reference to the drawings.

As shown in FIG. 2, the liquid crystal display panel of the present invention is specially provided with a battery alarm segment 10 at the right end in addition to the 8-digit numerical display section.

Further, at the right end of the protective filter 9, an index display body 11 (also referred to as 5afty-1ine) is provided by printing or the like.

The indicator 11 is provided at a position that indicates the viewing angle at the lower limit voltage for normal operation.

That is, assuming that the lower limit voltage for normal operation is 120% of the specified voltage, the indicator 11 is provided at the position where the line E intersects the protective filter 9 in FIG.

In this way, when the voltage is at the rated value, the viewing angle is close to directly above the display panel 1 in the range from 1 to 3, so that the indicator 11 and the alarm segment 10 appear to be separated as shown in FIG. 2A.

When the voltage decreases and the viewing angle reaches the second position, the distance between the indicator 11 and the alarm segment 100 becomes closer as shown in the opening of FIG.

When the voltage reaches the lower limit voltage, the viewing angle decreases to the position E, so the indicator 11 and alarm segment 10 are adjusted as shown in Figure 2 C.
appear to overlap.

This state signals a drop in the 1 drive voltage.

In other words, it will alert the operator that the calculator is in the malfunction area.

According to the above configuration, the display quality is improved because the indicator 11 does not get in the way of the displayed characters.

Furthermore, if the driving voltage of the alarm segment 10 is set to be somewhat lower than the driving voltage of the other numerically displayed segments, the above-mentioned dynamic voltages of both parts will similarly decrease as the power supply voltage decreases, so that the alarm will not be activated. 1 drive voltage of the segment 10 quickly reaches the lower limit voltage for normal operation, and a voltage drop can be reported while there is margin in the power supply voltage.

In the case of the above embodiment, even if the voltage drops by 20%, the alarm segment 10 and the indicator 11 appear to be separated from each other as shown in FIG. 2A when viewed from the position C, for example.

Therefore, the feature of Example H is that when the voltage is at the specified value, 10 and 11 do not appear to overlap even when viewed from any position, but when the voltage is below the specified value, io and il appear to overlap at a specific position. This appearance of overlap is used as a means of reporting a voltage drop.

Other embodiments Fig. 3 A: 5 ports, C: battery alarm segment 1
This is an example in which the display position of 0 is lowered and disappears from the display section as the voltage decreases.

In order to realize this, it is only necessary to make only the following portion 12 (shown with diagonal lines in FIG. 3) opaque from the position corresponding to the index 11 in FIG. 2 on the protective filter 9.

For example, paint it black. The operation of this embodiment is similar to that shown in FIG.

Figure 4 A2 and C are examples in which the numeric display is also used as the alarm segment 10, and S af ty-11ne11 is provided in a straight line below the 8-digit numeric display.

When the voltage decreases, the lower end of the numeric display becomes S aft.
It becomes visible in contact with y-1ine.

In this case, the structure of the conventional display panel is not changed at all, and only 5afty-1ine is added to the protective filter, so the conventional display panel can be used as is.

Figure 5 shows part of the calculator cabinet.
This is an example used as e.

In the figure, 13 is a cabinet, and 14 is a protrusion provided on the cabinet 13 for the index 11. If the tip of the protrusion 14 and the segment 10 appear to overlap, it means that the voltage has decreased.

In addition, although the above embodiment uses the viewing angle reduction characteristic of the FEM liquid crystal to notify of a drop in drive voltage, particularly to notify a drop in power supply voltage of an electronic device that uses a display panel as a display section, it can also be used for other notifications. .

As described above, the display device of the present invention can notify a drop in the drive voltage of the display panel with a simple configuration that only includes an indicator display that does not depend on the characteristics of the FEM liquid crystal.

Therefore, a device incorporating this display device does not need to be provided with a special means for notifying a drop in driving voltage, and the configuration of the device can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the display panel of the present invention, and FIG. 1 and 5 are explanatory diagrams for explaining the operation of FIG. 1, and FIGS. 3 to 5 are explanatory diagrams for explaining the operation of other embodiments. Code, 1: Display panel, 2: Alarm segment, 1
1: Index display body.

Claims (1)

[Claims] 1. In a display device using a field-effect liquid crystal, a display body made of the liquid crystal and an index display body that does not depend on the characteristics of the liquid crystal are provided, and the display body is adjusted based on a decrease in the driving voltage of the display body. A display device configured to notify a decrease in visual angle by using the above-mentioned indicator display.