JPH0137741B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device using a liquid crystal, and includes a first display section that displays graphs, numerical values, etc. in a negative manner depending on the state of voltage applied between electrodes facing each other via the liquid crystal; The present invention relates to the structure of a liquid crystal display device having a second display section that always displays scales, numbers, characters, etc. with transmitted light regardless of the state of the voltage applied between the electrodes.

Display formats of display devices using liquid crystals include negative display, in which light is transmitted only in the segment electrode shape, and positive display, in which light is transmitted in other parts except for the segment electrode shape. The former display type reduces the amount of light that enters the user's eyes, causing less fatigue for the user, and improves visibility because the brightly shining ``figure'' stands out against the dark ``ground.'' However, it has features such as being able to obtain a greater display effect than the latter display form. In liquid crystal display devices that provide negative display, scales and There is a tendency for parts such as numbers and characters to be displayed by printing and always using transmitted light, rather than being displayed using liquid crystals.

A liquid crystal display device capable of achieving such a display is disclosed in, for example, Japanese Utility Model Application Publication No. 58-138973 and shown in FIG. 1. That is, the liquid crystal display device includes a liquid crystal cell 6 in which a liquid crystal 5 is sealed between substrates 3 and 4 made of transparent insulating flat plates such as glass or plastic having segment electrodes 1 and common electrodes 2 on their inner surfaces; Polarizing plates 7 and 8 provided on the front and rear surfaces of the liquid crystal cell 6, a surface plate 9 provided in front of the front polarizing plate 7, and an illumination member 10 provided behind the rear polarizing plate 8. The liquid crystal cell 6 has a part that displays graphs, numbers, etc. in a negative manner according to the shape of the segment electrode 1 depending on the state of the voltage applied between the electrodes 1 and 2, and a part that always transmits light. The liquid crystal 5 is aligned in a different direction between one segment electrode or a portion corresponding to the segment electrode 1 and its vicinity and other portions, and the surface plate 9 is arranged so that the liquid crystal 5 is arranged in a different direction from the portion corresponding to the segment electrode 1 and its vicinity. A first display section is formed by using a light-transmitting window section 11 in a portion facing the window section 11, and the other section except for this window section 11 is colored with a pattern or color according to the display device to block light. A portion opposite to the portion through which the light is transmitted forms a second display portion as a display portion 12 that displays scales, numbers, characters, etc. with transmitted light.

The liquid crystal display device having such a configuration displays graphs, numerical values, etc. in a negative manner on the window 11 of the surface plate 9 according to the state of the voltage applied to the electrodes 1 and 2, and also displays a scale on the display section 12 at all times. , numbers, characters, etc. are displayed using transmitted light.

By the way, polarizing plates 7,
8, the light from the illumination device 10 is blocked by 70 to 80% when it passes through the polarizing plates 7 and 8, resulting in significant attenuation. The disadvantage is that the display section 12 is darker than the window section 11, resulting in a large difference in the brightness of the front panel 9.

The present invention has been made based on the above-mentioned drawbacks, and an object of the present invention is to provide a liquid crystal display device that can effectively transmit light from an illumination device to a display section that always displays scales, numbers, characters, etc. in transmitted light. It is something to do.

In order to achieve the above object, the present invention provides a liquid crystal display device in which a gap between opposing substrates is filled with liquid crystal. The invention is characterized in that a polyvinyl alcohol layer is provided in which a polarizing part for polarizing light and a light shielding part for blocking light are formed in the same plane.

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

Components having the same or similar functions as those of the conventional example are given the same reference numerals, and detailed explanation thereof will be omitted.

The opposing surfaces of the two opposing substrates 3 and 4 are oriented in a specific direction (this direction is the same as the polarization axis direction of the polarizing plates 7 and 8 and determines the polarized light to be transmitted).
A polyvinyl alcohol (PVA) film is attached under tension to the PVA layers 13 and 14.
are provided thereon, electrodes 1 and 2 are provided thereon via a protective layer 15 made of an overcoat material such as polyimide resin or polyamide resin, and the gap between them is filled with liquid crystal 5 to form a liquid crystal cell 6. The lower PVA layer 14 includes a polarizing section 14A that deflects the light from the illumination device 10 to the portion where the electrodes 1 and 2 are provided, a light transmitting section 14B that transmits the light, and a light transmitting section 14B that transmits light to areas other than the polarizing section 14A and the light transmitting section 14B. The light shielding portion 14C is formed on the same plane as the light shielding portion 14C provided on the front substrate 3.
The PVA layer 13 has a polarizing portion 13A formed at the same position as the polarizing portion 14A of the PVA layer 14 provided on the rear substrate 4.

The polarizing portions 13A and 14A include the polarizing plates 7,
8, the polarization axis direction has a function of transmitting only polarized light in a specific direction, for example, the PVA layer 13,
Mask the other parts except the polarizing parts 13A and 14A on the 14th surface and apply iodine or dichroic dye.
The light-transmitting portion 14B is provided by printing on the PVA layers 13 and 14, and nothing is applied to the PVA layer 14, and the light-shielding portion 14C protects the polarizing portion 14A and the light-transmitting portion 14B on the surface of the PVA layer 14. It is provided by masking and printing a dark-colored (black or blue, etc.) dichroic dye. By the way, since nothing is applied to the other parts of the PVA layer 13 provided on the front substrate 3 except for the polarizing part 13A, the part facing the light-transmitting part 14B is the part that transmits light, and the part facing the light-blocking part 14C is This will be a dark colored display area where no light will pass through.

Therefore, the polarizing parts 13A and 14A become a first display part that displays graphs, numerical values, etc. in a negative manner depending on the state of the voltage applied between the electrodes 1 and 2, and the transparent part 14
The B portion becomes a second display portion that always displays scales, numbers, characters, etc. with transmitted light regardless of the state of the voltage applied between the electrodes 1 and 2, and the light shielding portion 14C portion is always dark in color.

The liquid crystal display device of the present invention configured as described above corresponds to a first display section that displays graphs, numerical values, etc. in a negative manner depending on the state of the voltage applied between the electrodes 1 and 2 facing each other via the liquid crystal 5. A substrate 3 corresponding to a second display section, which is provided with polarizing sections 13A and 14A only in the substrates 3 and 4, and displays scales, numbers, characters, etc. in transmitted light at all times regardless of the state of the voltage applied between the electrodes 1 and 2. , 4 is provided, and a light shielding portion 14C is provided so that light does not pass through only the other portions of the substrate 3 and 4, which correspond to the portions where light should not be transmitted at all times. By providing this, the second display section, whose light is significantly attenuated, can be made brighter than in the past, allowing the user to read the display better.

In addition, the polarizing parts 13A, 14A, the transparent part 14B,
The light-shielding portion 14C is formed by repeating mask printing or the like on the PVA layers 13 and 14 that have been pasted on the substrates 3 and 4 in advance, and is formed by applying a conventional surface plate 9 (see FIG. 1) to the liquid crystal cell 6 itself. ) functions, and since the substrate 3, which is a relatively hard flat plate made of glass or plastic, is located in front of the liquid crystal cell 6, a polarizing plate 7 (see FIG. 1) is arranged in front of the liquid crystal cell 6. It has a structure that is more resistant to external impacts than the conventional example, and therefore the surface plate 9, which was provided to prevent the polarizing plate 7 from being scratched, can be eliminated. Since the parts 13A and 14A are provided in a state where they are shielded from the outside air, iodine, which has good translucency and whose use was previously restricted due to its sensitivity to moisture, can now be used as a polarizing member. Contrast can be increased.

Further, the liquid crystal cell 6 is provided with electrodes 1 and 2 portions forming a first display portion, a light-transmitting portion 14B portion forming a second display portion, and a light-shielding portion 14C portion that does not transmit light. The first display part was provided in the liquid crystal cell 6, and the second display part and the light-blocking part were provided in the surface plate 9, so that the first
The display section and the second display section are the substrate 3 of the liquid crystal cell 6.
Compared to the conventional example in which the space is separated by the thickness of the polarizing plate 7 and the surface plate 9, the parallax between the first display section and the second display section is reduced, and reading problems can be solved.

Although one embodiment of the present invention has been described above in detail, it goes without saying that the present invention is not limited to the above embodiment and includes various modifications.

For example, although the light shielding portion 14C is provided only on the substrate 4, the PVA layer 13 of the other substrate 3 opposite thereto
In addition, in the case of a so-called guest-host type in which a dichroic dye is added to the liquid crystal 5, the polarizing part 1 may be provided in the polarizing part 1.
It is not necessary to provide one of 3A and 14A.

As detailed above, according to the present invention, in a liquid crystal display device in which a gap between opposing substrates is filled with liquid crystal, a transparent portion that transmits light from a light source is provided on at least one of the inner surfaces of the opposing substrates. By providing a polyvinyl alcohol layer in which the polarizing part that polarizes light and the light shielding part that blocks light are formed on the same plane, light from the lighting device is effectively transmitted to the display part that always displays scales, numbers, characters, etc. in transmitted light. It is possible to provide a liquid crystal display device that can perform

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a conventional liquid crystal display device, and FIG. 2 is a sectional view of the liquid crystal display device of the present invention. 1, 2... Electrode, 3, 4... Substrate, 5... Liquid crystal, 10... Lighting device, 13, 14... Polyvinyl alcohol (PVA) layer, 13A, 14A...
...polarizing section, 14B...light-transmitting section, 14C...light-shielding section.

Claims (1)

[Claims] 1. In a liquid crystal display device in which a gap between opposing substrates is filled with liquid crystal, at least one of the inner surfaces of the opposing substrates is provided with a light-transmitting part that transmits light from a light source, a polarizing part that polarizes light, and a light-blocking part that blocks light. 1. A liquid crystal display device comprising a polyvinyl alcohol layer formed on the same plane.