JPH0521234B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a display called a module type in which a data address circuit and a display medium including an active matrix section addressed by the data address circuit are integrated. Concerning improvements to equipment.

[Conventional technology]

Conventionally, XY matrix display devices using liquid crystals have been widely known (in short, Japanese Patent Application Laid-Open No. 129394-1983)
(see publication).

The XY matrix display device using this crystal is
As shown in FIG. 5, a semiconductor switch element 16 is formed for each pixel on a semiconductor thin film, row lines X and column lines Y are wired on the semiconductor thin film, and a liquid crystal cell 17 is stacked on this semiconductor thin film. It has a formed structure.

The semiconductor switch element 16 used here is
Specifically, as shown in Figure 6, MOS/FET
The gate is connected to the row line X, the drain is connected to the column line Y, and the source is connected to one counter electrode of the liquid crystal cell 17.

A scanning pulse is sequentially supplied to the row line X in synchronization with a horizontal synchronizing signal, and a video signal for one horizontal period is simultaneously supplied to the column line _Y for each horizontal period. When a scanning pulse is applied, all the semiconductor switch elements 16 of the row line X _o are turned on, and the video signal is passed through the drain and source to the capacitance C existing between the opposing electrodes of the liquid crystal cell 17.
The charged voltage is applied as an electric field to the liquid crystal cell 17 to display a brightness proportional to the magnitude of the video signal.

As a concrete driving method, as shown in A in Fig. 7, a scanning pulse is applied to the same row line at one frame period, and therefore, the scanning pulse is applied to the same row line at one frame period. When extracting video signals, use the bidirectional nature of the liquid crystal,
As seen in Figure B, the video signal is taken out alternately in a positive state and a negative state for each frame, and for the same liquid crystal cell in that row, as seen in Figure C. , an alternating current signal voltage that is inverted between positive and negative every frame is applied.

By the way, in the above-mentioned modular display device, if the display medium itself performs display by emitting light, it can perform display by emitting light, or if it can perform display by receiving light. For example, a shield electrode is provided on the data address circuit because external light increases the leakage current of the semiconductor switch element constituting the data address circuit, causing malfunction. Note that the data address circuit usually consists of multi-stage shift registers.

Figures 3 and 4 show conventional display devices provided with shield electrodes (if necessary,
60-224246), FIG. 3 is a cutaway side view of the main part showing the vicinity of the data address circuit.
FIG. 4 is a block diagram showing the entire modular display device.

In the figure, 1 is a substrate made of silicon (Si), etc., 2 is an insulating film made of silicon dioxide (SiO ₂ ), etc., 3 is a power bus line, and 4 to 6 are semiconductor elements built into substrate 1. , 7 is a ground bus line, 8 is an insulating film made of silicon dioxide, 9 is a shield electrode, 18 is an active matrix section configured by two-dimensionally arranging memory cells and display cells, 19 and 20 is an X and Y data block composed of multi-stage shift registers, etc.
Each address circuit is shown. Note that the power bus line 3, the wirings 4 to 6, the ground bus line 7, and the shield electrode 9 are usually made of aluminum (Al).

[Problem that the invention seeks to solve]

Generally, pinholes are likely to be formed in an insulating film in a semiconductor device, and cracks are likely to occur at stepped portions.

Even in the conventional display device, if a crack occurs in the stepped portion of the insulating film 2 in FIG. This can cause short circuits with other wiring. Note that floating the shield electrode 9 has also been practiced, but if short circuits occur at multiple locations, the circuit will still malfunction.

[Means for solving problems]

In the display device of the present invention, in a modular display device in which a data address circuit for addressing an active matrix portion is integrated with the display portion, a semiconductor element constituting the data address circuit is fabricated. The structure is such that an island-shaped shield electrode that covers only the semiconductor element portion and is maintained in a floating state is provided on the substrate.

[Effect]

According to the above configuration, even if a short circuit occurs between the shield electrode and another electrode, the shield electrode will only be clamped to the potential of the shorted wiring, and the range of the circuit that will cause malfunction will be very small. If the connection between different power bus lines, signal bus lines, or ground bus
Short circuits between lines hardly occur.

〔Example〕

FIG. 1 is a cross-sectional side view of essential parts showing one embodiment of the present invention, and the same parts as those explained in connection with FIG. 3 are indicated by the same symbols.

In the figure, reference numeral 10 indicates a signal bus line, reference numerals 11 to 13 indicate wiring of semiconductor elements formed in the substrate 1, and reference numerals 14 and 15 indicate island-shaped shield electrodes.

As can be seen from the figure, the shield electrodes 14 and 15 in this embodiment do not cover the entire surface of the circuit as in the conventional case, but cover only necessary parts of the circuit, for example, only the transistor parts that require shielding. It's meant to be covered.

FIG. 2 is a plan view of essential parts showing another embodiment of the present invention, and the same parts as those described with reference to FIGS. 1 and 3 are indicated by the same symbols.

In the figure, Q1 and Q2 indicate transistors.

According to this figure, the shape and arrangement of the island-shaped shield electrodes 14 and 15 are clearer.

In this embodiment, shield electrodes 14 and 15 are formed only at the transistors Q1 and Q2, and are particularly useful for bus lines that do not require shielding and are likely to cause failure of the entire circuit in the event of a short circuit. are arranged so that they do not intersect as much as possible.

〔Effect of the invention〕

The display device of the present invention includes a data address circuit for addressing an active matrix circuit, and island-shaped shield electrodes that cover each predetermined portion of the data address circuit that is arbitrarily divided and are maintained in a floating state. It is structured to include the following.

By adopting such a configuration, even if a short circuit occurs between the island-shaped shield electrode and the circuit below it, the island-shaped shield electrode will only be clamped to the potential of the circuit where the short circuit occurred. It does not interfere with other circuits and cause malfunction, and
The probability of a short circuit occurring itself is reduced.

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of the main part of one embodiment of the present invention, Fig. 2 is a plan view of the main part of another embodiment, Fig. 3 is a cutaway side view of the main part of the conventional example, and Fig. 4 is a modular display. A block configuration diagram showing the entire device, FIG. 5 is a plan view of the main parts to explain the structure of a general active matrix display device, and FIG. 6 is a circuit diagram of the main parts of the device shown in FIG. FIG. 7 shows diagrams for explaining the driving method of the device shown in FIG. 5, respectively. In the figure, 1 is a substrate made of silicon, etc.
2 is an insulating film made of silicon dioxide or the like; 3 is a power bus line; 4 to 6 are wirings for semiconductor elements built into the substrate 1; 7 is a ground bus line; 8 is a ground bus line;
1 is an insulating film made of silicon dioxide, 9 is a shield electrode, 10 is a signal bus line, 11 to 13 are semiconductor element wirings formed in the substrate 1, 14 and 15 are island-shaped shield electrodes, and 16 is a semiconductor switch. element, 17 is a liquid crystal cell, 18 is an active
In the matrix section, 19 and 20 are data address circuits, and Q1 and Q2 are transistors, respectively.

Claims (1)

[Claims] 1. In a modular display device in which a data address circuit for addressing an active matrix section is integrated with a display section, a semiconductor element constituting the data address circuit is fabricated. 1. A display device comprising an island-shaped shield electrode that covers only a semiconductor element portion and is kept in a floating state on a substrate.