JPS6310194A - Display unit - 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] [Industrial Application Field] The present invention relates to a flat type device having row electrodes and column electrodes and forming a display by emitting light only from a selected portion corresponding to the intersection of both electrodes. Display devices, especially fluorescent display tubes (VFD) and plasma display devices (FDP)
This invention relates to display devices with relatively high driving voltages, such as electroluminescence devices (ELD).

[Conventional technology]

As a flat display device that replaces cathode ray tubes.

Currently VFD, PDP, ELD, or liquid crystal display device (
LCD), etc. have been developed and put into practical use.

When displaying a single character, figure, image, etc. with these display devices, an XY matrix electrode structure having row electrodes and column electrodes is generally adopted. That is, as shown in FIG. 3, it has X electrodes x1 to Xs along the row direction and Y electrodes Y1 to Yn along the column direction intersecting these, and pixels P, 1°P, ...This is a structure in which Pan is formed. And lead wires 1□~ll11 and 2□~2
When a drive signal is selectively applied via n, a display is formed by the pixel P located at the intersection of the selected electrodes X and Y.

A display device with an X-Y matrix electrode structure has the basic configuration described above.1 For example, in a VFD, a phosphor layer is deposited at the position of the pixel, and electrons emitted from an electron source (not shown) are transferred to a selected pixel. The light impinges on the phosphor layer on the P and generates light emission.

Further, in ELD, a phosphor layer sandwiched between one electrode X and Y is excited by a voltage applied between selected electrodes to generate EL light emission.

Furthermore, in FDP, a discharge occurs between one selected electrode, and the introduced gas atoms are excited to emit light (actually, each pixel P is divided into small chambers so that crosstalk between one light emission does not occur). ) In the LCD, the orientation of liquid crystal molecules between the electrodes X and Y changes to form an optical display.

In this way, although there are differences in the specific configurations of individual display devices, basically signals are applied to the electrodes X and Y individually, and a display is formed at the intersection of the two.

Therefore, it is necessary to individually apply signals to each electrode x1 to X+m and Y1 to Yn via the lead wires 11 to 1 and 2□ to 2n. Therefore, in this type of display device,
(Number of electrodes X+number of electrodes Y) drive circuits (hereinafter referred to as drivers) must be prepared.

On the other hand, in recent years, even in flat display devices, there has been a demand for more detailed displays, larger display capacities, and larger screens, and as a result, the number of drivers required has also increased.

For example, as a display device for computer terminals or OA equipment, 320 x 240 = 76,000, or 640
x 400 = 256,000 pixels are required. In this case, the former requires 560 drivers, and the latter requires 1040 drivers.

As described above, when the number of drivers increases, it is not easy to configure them with individual elements, and they are integrated into LSI. In this case, generally, as shown in Fig. 4, a driver IC is integrated with a logic section (which has the function of temporarily storing display signals and outputting display signals input in series in parallel) and a driver section. Constructed as.

In other words, if the LSI drives 1m electrodes X, m
Driver section D consisting of driver elements DR1 to DR Otori
R and a shift register S that converts serial input to parallel output.
HR□~SHRm, gate parts NR1~NRm for sending out the display signal stored in this shift register to the driver part while keeping the timing, buffers BF~BF4 for input/output of input signals and timing signals, etc. It is composed of a logic section LG consisting of. As the display density of the driven display device improves, the degree of integration of the driver element C also improves, and 10 to 32 driver elements are now mounted on one IC.

[Problem that the invention seeks to solve]

By the way, in the driver IC structure shown in FIG. 4 mentioned above, V
When attempting to drive a display device such as an FD, PDP, or ELD, a driver element needs to have a withstand voltage of about 100 to 200V. This is because if the number of electrodes on the display device side increases, a dynamic drive method must be used as the drive method.
In order to obtain a flicker-free display surface, the duty ratio is reduced. If you want to obtain the necessary brightness when the duty ratio is small, the voltage value must be 100 to 20QV.
It becomes high.

Therefore, the driver IC for the above-mentioned light-emitting type display device
is a high voltage type as mentioned above.

On the other hand, the logic section LG integrated with the driver element
is generally driven with a voltage of about 5V.

In other words, the conventional driver IC can be said to be a mixture of a high-voltage type driver section OR and a low-voltage driven logic section LG.

Incidentally, the structures and manufacturing processes of high-voltage transistors and low-voltage drive transistors are generally different. Therefore, it must be said that it is extremely difficult and wasteful to fabricate high-voltage and low-voltage transistors on a single chip. This poses a major problem in promoting the widespread use of flat display devices.

[Means for solving problems]

The present invention was made in view of the above-mentioned circumstances, and
First, the logic section and driver section of a conventional driver IC are separated and each is formed into an IC or an array. The logic part is fabricated as a monolithic IC on a Si single crystal substrate, and the driver part is formed by a thin film transistor (hereinafter referred to as TPT) array.
By incorporating each into the periphery of the substrate of the display device or into the package, a modular configuration is achieved.

[For production]

The applied display signal first enters a monolithic IC logic section, where the data is serial-parallel converted or temporarily stored. The signal is then synchronized by a synchronizing signal, enters a driver section formed of TPT, and is applied to each electrode of one display device.

Since the logic section is driven at a low voltage of about 5V, there are fewer problems such as heat generation, and high integration is possible. Furthermore, since the driver section is composed of only high-voltage transistors having the same structure, the structure is simple. Therefore, the entire display device can be constructed at low cost.

〔Example〕

FIGS. 1(a) and 1(b) are a plan view and a side sectional view schematically showing a display device according to the present invention.

Here, 10 is a substrate, and a display section 1 is placed on this substrate 10.
For example, in the case of an ELD, a phosphor layer and X and Y electrodes sandwiching the phosphor layer directly or through a dielectric layer are provided. In addition, in the case of a VFD, there is an anode conductor with a phosphor layer adhered to its upper surface, a control electrode placed apart from the anode conductor in a direction that crosses it, and an electron emission source stretched above the anode conductor. The display section 11 is constructed from the cathode, and the anode conductor and control electrode serve as X and Y electrodes, respectively. Furthermore, in a PDP, X and Y electrodes are arranged facing each other with a space between them.

This space is filled with discharge gas to form the display section 11.

In any type of display section, the X electrode and Yf! Pixel P (Pu, P.

...P@n) is configured as shown in FIG. 1(a).

Reference numeral 12 denotes a driver section formed of a TFT array, which is the gist of the present invention. There are various types of output circuit configurations for the driver section 12, such as an open collector type, a totem pole type, and a resistor pull-down type.

Alternatively, an active pull-down type is known. Among these, the active pull-down type has a circuit configuration as shown in FIG. 2, for example. That is, when a display signal is applied to the input terminal IN, the transistor Tr turns on,
A driver current is supplied from transistor Tr to the base of output transistor Tr. Thus, via the output terminal OUT.

The electrode connected to this will be driven. At this time, the output of inverter IV causes transistor T
r4 is in the off state, and power from the power source Vc is efficiently supplied to the drive electrodes.

On the other hand, when there is no display signal at the input terminal IN, the transistor Tr is turned on by the output of the inverter IV, keeping the electrode connected to the output terminal OUT at ground potential. Therefore, crosstalk between one light emission and the like can be reliably prevented.

In FIG. 2, r-r4 are bias resistors and protection resistors.

Therefore, the driver section 12 in FIG. 1 includes a driver element having a circuit configuration as shown in FIG.
The number of electrodes is 1 and is made of TPT.

Various configurations can be considered for the arrangement of the driver section 12, but the example shown in FIG. It is.

By the way, TPT is generally formed on a semiconductor substrate or a substrate such as glass ceramics by vapor deposition technology. Now, if the substrate 10 is made of glass or ceramic material, the driver section 12 is formed directly on the periphery of this substrate 10, and in the process of forming the driver section 12, the wiring 13 for connection with the electrode of the display section 11 is formed. Alternatively, it may be formed by vapor deposition. In this case, the manufacturing process for one display device is simplified and the cost can be reduced.

If the manufacturing process of the driver unit 12 using TPT and the manufacturing process of the display unit 11 are significantly different, the driver unit 12 may be fabricated in a separate process on a separately prepared TFT substrate.
1 on the peripheral edge of the substrate 10, and wiring 13 is performed by means such as wire bonding.

Furthermore, 14 is a logic section, which is formed by a monolithic IC in which a shift register, a latch circuit, a gate circuit, etc. are integrated.

Since the logic section 14 is formed only of elements driven at a low voltage of about 5 V, it can be highly integrated, although the circuit configuration is more complicated than that of the driver section 12. The logic section 14 is made of silicon, for example, because the element structure is complicated and high integration is required as described above.
It is fabricated on a single crystal wafer, formed into a chip, and attached to the peripheral edge of the substrate 10. The IC structure is MOS type, C
MO3 type, bipolar type, etc. can be selected as required.

Further, 15 is a wiring that connects the logic section 14 and the driver section 12, and any means such as wire bonding or printed wiring can be used. Furthermore, the logic section 14 may be divided into several parts depending on its degree of integration and connection structure with the driver section 12. In the embodiment shown in FIG. 1(a), four logic sections 14 are provided.

Reference numeral 16 denotes a container portion that is sealed to the peripheral portion of the substrate 10 with a sealing material made of, for example, low melting point glass. FDP
Here, the container portion 16 and the substrate 10 form a sealed space that confines the discharge gas. In VFD, a vacuum container car is also formed.

In the embodiment shown in FIG.
4, it is effective from the viewpoint of protecting the element.

However, this driver section 12. The logic section 14 does not necessarily need to be enclosed in an airtight container.

It may be arranged around the substrate 10 outside the container, on the back surface, or the like. However, in this case, the driver section 12
It is also necessary to provide protection for the logic section 14, such as applying a resin coat to the surface.

Thus, the power supply for the driver section 12 and the power supply and input terminal for the logic section 14 are led out to the outside through, for example, the sealed portion between the substrate 10 and the container section 16.

A display is formed on the display section 11 by applying a required signal to the terminal 22.

〔effect〕

As described above, the display device according to the present invention.

A logic section that processes display input signals and a driver section that applies drive signals to each electrode are separated and integrated into an IC or an array. Moreover, the logic section driven at low voltage is a monolithic IC built in single crystal Si.
The driver section is a TFT array.

Therefore, when converting to IC and array, respectively,
The structure is simple and manufacturing is easy.

That is, it is possible to reduce the cost of the logic section and the driver section, and the entire display device can be constructed at a low cost, which has an excellent effect in promoting its widespread use.

In particular, when performing matrix drive in light-emitting display devices such as EL, PDP, and VFD, the electrode voltage must be high, and driver ICs that integrate the logic section and driver section are extremely expensive. .

However, if the present invention is applied to these display devices, the driver element can be constructed from a TFT array at low cost, and therefore an excellent effect can be achieved in terms of cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a plan view and a vertical cross-sectional view of a display device showing one embodiment of the present invention, FIG. 2 is a diagram showing the main circuit configuration of the same embodiment, and FIG. FIG. 4 is a circuit configuration diagram showing a conventional driver IC. 11... Display section 12... Driver section 14... Logic section 15... Wiring patent applicant Futaba Electronics Co., Ltd. Figure 1 (b) Figure 2, Figure 3 Figure 4 Figure G

Claims (1)

[Claims] In a display device that has a plurality of row electrodes and a plurality of column electrodes and forms a display by selectively applying a drive signal to both of these electrodes, a drive signal is directly applied to each of the row electrodes and column electrodes. A display consisting of a driver section consisting of a thin film transistor array, a logic section consisting of a monolithic integrated circuit that receives display input signals and sends them to the driver section at a predetermined timing, and a group of wires connecting this logic section and the drive section. Device.