JPS59216185A - Panel for display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a display panel using liquid crystal, and particularly to a display panel that works as a display device on its own (and also works as a large display device in combination with a projector). Regarding display panels.

[Background of the invention]

Projection type TVs are the mainstream of conventional large TVs, but this
The system uses lenses to project light emitted from two cathode ray tubes onto a curved screen, which has the following drawbacks: the device is extremely large, the quality of the image deteriorates depending on the viewing angle, and it requires powerful light. There was a problem.

[Purpose of the invention]

An object of the present invention is to provide a device that easily enables a large-screen flat display using an extremely compact device and a flat screen.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides a transmissive shape in which the outer wall surface of one transparent substrate of a conventional liquid crystal display panel is formed into a circular Fresnel lens surface consisting of a planar collection of annular zones cut out from concentric spherical surfaces. By forming a reflective panel or forming a reflective film on the Fresnel surface to create a reflective panel, it can function as a display panel itself, and by combining these with a projection device, it can be used as a large display device. This makes it possible to do this.

[Embodiments of the invention]

Hereinafter, the present invention will be explained by examples.

FIG. 1 shows an embodiment of the present invention, which, as seen in the central figure, consists of a transparent substrate 1, a transparent substrate 2, and a liquid crystal layer 3 sandwiched between the split substrates. Looking further at the split substrate, we can see that the substrate 1 is arranged in an array on the inner wall of the transparent substrate 1, such as glass, on the liquid crystal layer 3 side, as shown in the enlarged cross-sectional view in Part 2 of the same figure. A transparent electrode 5 constituting a surface element and a thin film transistor (
TPT) 6 is formed. On the other hand, the outer wall of the substrate 2, that is, the surface opposite to the liquid crystal layer forms a circular Fresnel lens consisting of a planar collection of thin ring zones cut out from concentric spherical surfaces. Furthermore, a reflective film 8 is formed on the outer wall surface of this substrate 2, and light is reflected here. On the other hand, a transparent electrode 7 is formed on the entire inner wall of the substrate 2.

FIG. 2 shows a cross-sectional view and a plan view of the TPT 6 formed on the transparent substrate 1 shown in FIG. 1. First, 5
is an individual transparent electrode for liquid crystal formed on the transparent substrate 1, and ■n203. SnO2 or its mixed crystal IT
A transparent electrode made of O (Indium Tin Oxide) or the like, or a thin metal electrode such as Au or Ar may be used depending on the case. The gate electrode 11 is made of Mo, Cr
.

A metal such as W is used. On top of this, Si3N4, Si3
An insulating film 15 made of silicon nitride containing N4:H, that is, hydrogen, or 5I02 or the like is formed. Further, an amorphous hydrogenated silicon layer, that is, a-8::H7@12, is deposited at a position corresponding to the gate 11 on top of this, and T
PT active region is formed. a-3i: The H layer is normally an undorfed thin film, but it is effective to provide an n layer doped with phosphorus or the like in the contact region to facilitate contact with the source and drain.

The material for TPT is not limited to a-8i:H, but also Cd
S.

It is also possible to use materials such as CdSe, Te, or crystalline or polycrystalline silicon.

Furthermore, when a-3i:H is used, since it exhibits conductivity due to light, it is necessary to provide a light shielding layer or the like in the gap between the source and drain to prevent this. This is not shown in FIG.

The source electrode 13 and the drain electrode 14 are formed as shown, and the drain 14 is contacted with the transparent electrode 5 through a through hole 16 provided in the insulating film 15. As an electrode metal, AI! , Au, Cr, Mo,
Use W etc.

FIG. 3 schematically shows the circuit configuration of the transparent electrode 5 and the accompanying TPT 6 constituting the pixel formed on the transparent substrate l as described above.

There are various driving methods, for example, gate line 1
1, add an image signal to source electrode 13, drain electrode 1
When a driving voltage is applied between 4 and 4, the T of the pixel at the intersection of these
PT is conductive only while a signal is input to the gate line, and an electric field is generated between the drain electrode 14 and the counter electrode 7,
Display is performed by changing the alignment state of liquid crystal molecules in the liquid crystal layer 3.

Another driving method is to apply a driving voltage to the gate electrode ′
In addition, an image signal is applied between the source and drain. As a result, the potential applied to the liquid crystal changes, and the alignment state of the liquid crystal changes.

In any case, lead-out electrodes for a gate electrode and a source electrode are provided on the substrate 1, and a drive voltage is supplied through these. Alternatively, in addition to the electrodes, it is also effective to incorporate a driving IC directly onto the substrate in terms of miniaturization of the device, which also leads to improved reliability. Wire bonding or CCB (Control
ed Co11apsed Bonding) etc. can be used.

A dynamic scattering mode (DSM) liquid crystal, a nematic (TN) liquid crystal, or the like is used as the liquid crystal, and various alignment states of liquid crystal molecules and installation of a polarizing plate, a 4 o'clock one-wavelength plate, a reflecting plate, etc. are carried out as appropriate.

The transparent substrate 2, which has a circular Fresnel lens surface formed on its surface, needs to be easily made by a method such as hot pressing, so it is also possible to use crow etc., but organic plastics that can be easily deformed by heat can be used. It is convenient to use a transparent material, for example polymethyl methacrylate. The thickness of this plastic is preferably below Tm, and most preferably around 250 μm. The production method is the same as when making records, by pressing. On the Fresnel lens surface created by hot pressing, Af is formed as a reflective film 8 by vacuum deposition. Further, on the opposite surface, like the transparent electrode 5 of the substrate 1, In
203, a transparent electrode 7 made of SnO2, ITO, etc. is formed on the entire surface.

Finally, the substrates 1 and 2 are placed with the transparent electrodes facing each other with the spacer 4 in between, and the liquid crystal 3 is filled between them. This display panel operates as a display panel even in this state by applying a driving voltage, but another major feature of this panel is that it is equipped with an optical system and a screen as shown in Figure 4. By introducing it into a projection device consisting of a combination, it can be used as a large-sized projection display panel. In the same figure, 21 is a display panel of the present invention placed on the operation table 20, which is explained in FIG. The light that exits here is reflected by the display panel 21, passes through the lens 23, and is reflected in the mirror 2.
4 and projected onto a screen (not shown). This situation is shown in FIG. 6, where the light that exits the light source 25 and passes through the lens 26 is reflected by the reflective surface 8 of the substrate 20, which is a thin ring cut out from a spherical surface centered at the 0 point. It consists of a circular Fresnel lens surface consisting of a planar collection of bands, and the substrate 2 serves as the Fresnel lens. This zero point is offset from the center of the panel 21 toward the light source 25 side. The reflected light from the reflective surface 8 is collected by a lens 23 and reflected by a mirror 24. As a result, a panel approximately 10 inches in size is enlarged to 100 inches or more and projected onto a screen, and the display panel shown in Figure 1 becomes a TV.

When displaying images, a 100-inch TV is realized. Color TV images can also be easily received using this method. That is, each pixel of the display panel in FIG.
, G, B or CLY, M, etc., colorization can be realized. Also,
As shown in FIG. 5, the display panel 21 can be removed from the operation console 20 and used as a relatively small display panel.

What is important in the configuration of the display panel shown in Figure 1 is that the display medium, the liquid crystal, and the Fresnel lens are placed extremely close to each other. It works very effectively in providing images.

FIG. 7 shows another embodiment of the invention. 1st
The structure is almost the same as that shown in the figure, but the only difference is that there is no reflective film 8. That is, a transmission type method is used when projecting the display screen. A light source is placed below the Fresnel lens substrate 2, and the light that has passed through the display panel is projected onto the screen after passing through a lens and a mirror in the same manner as in the above embodiment.

FIG. 8 shows yet another embodiment of the present invention, in which individual transparent electrodes 5 and associated switching elements are formed on the inner wall of Fresnel lens substrate 2. In FIG.

In this case, the transparent electrode 7 formed on the inner wall of the counter substrate l serves as a common electrode.
It is also possible to provide switching arrays on the substrate 1 and the substrate 2, as mentioned in the specification of No. 32,
A significant reduction in the number of terminals similar to that described in the above specification can be achieved.

In the embodiments described above, the substrate 2 has been described as a single substrate, but as shown in FIG. 9, it does not matter if it is a set of two substrates.

A possible combination is that 31 is made of plastic and 30 is made of glass. In this case, the transparent electrode is deposited on the glass substrate, and the Fresnel lens pattern is formed on the plastic substrate 31, and then the two are glued together. in this case,
The thickness of the substrate 2 after bonding is preferably thinner, preferably less than 1 mm, and most preferably about 250 μm.

〔Effect of the invention〕

According to the present invention, there is provided a display panel which is a flat display panel by itself and which can form a large-sized projection display device by introducing it into an optical system. It is extremely useful for display panels and displays for various information terminals.

Furthermore, the display panel of the present invention has a simple structure;
Since it is a portable display panel that can provide clear images, it is highly anticipated that the field of application will expand.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view and a partially enlarged view of an embodiment of the display panel of the present invention, and FIG. FIG. 3 is a diagram schematically showing the circuit configuration of a display panel of the present invention, FIGS. 4 and 5 are diagrams showing an example of application of the present invention, and FIG. 6 is a diagram showing the optical path of FIG. 4. 7 to 9 are diagrams showing other embodiments of the present invention. In the figures: 1... Transparent substrate 2... Fresnel lens substrate 3... Liquid crystal 4... Spacer 5・・・
・Individual transparent electrode 6...Switching element 7...
・Transparent electrode 8... Reflective film 11... Gate electrode 12... A-5i layer 13... Source electrode 14... Drain electrode 15... Insulating film
16...Contact hole 20...Operation table 21...Display panel 22...
・Lamp house 23...Meniscus lens 24
... Mirror 25 ... Light source 26 ... Lens agent Junnosuke Nakamura + 1 Part 12F1 ″f3 Figure '5J7'6 Figure 9A

Claims (1)

[Claims] (1) A liquid crystal layer is sandwiched between a pair of opposing transparent substrates, a switching element is incidentally provided on the inner wall of one of the substrates, transparent electrodes constituting pixels are provided in an array, and the other substrate is provided with a switching element in an array. 1. A liquid crystal display panel comprising a single transparent electrode provided on an inner wall of the substrate, wherein an outer wall surface of one of the substrates is a circular Fresnel lens surface. (2. The liquid crystal display panel according to claim 1, wherein a reflective film is formed on the Fresnel lens surface of the substrate.