JPS58134689A - Image 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 The present invention relates to a fine-grained image display device using a liquid crystal.

A conventional image display device is shown in FIG. LCD and MO8 type F
It is constructed by combining KT arrays. In Figure 1, the MO formed in the semiconductor layer constituting the unit pixel
8-type FKT1a% signal storage capacitor 2a, and liquid crystal cell 3. This basic operation will be clarified. First, M.O.
When a type 8 FET is made into a P channel and a pulse voltage of G)@ is applied as a gate signal to the gate line xi, FI
The capacitor 2aK is charged through the applied image signal tri F'F, T1a. When the negative pulse disappears, the FET 1a becomes the off state, and the capacitor 2aK is charged.
The charged voltage is held while being discharged through the liquid crystal cell and the off-resistance of the FET. Then 1. Change the gate signal from xi to xi+s, Z? :+2 and red check in line order,
Is there a ryozo trust that corresponds to that position? Ti,? /1°
By applying voltage to +1..., the entire image can be displayed. The six opposing electrodes are made of transparent material attached to the entire surface of glass or the like, and 4 in FIG. 1 is the common electrode terminal. The non-oil electrode is always kept at a certain potential. Now, these types of image display devices are suitable for displaying analog signals and moving images, and for displaying small scale TV images, but they are also suitable for displaying images that do not require halftones or still images. d) was inappropriate. This is because, as mentioned above, since the signal V that is fully charged in the capacitor 2a is discharged through the liquid crystal cell 3a'), writing operations are always performed, and fC and Ichikawa at both ends of the capacitor gradually become -1.
After 5 minutes, the frost and pressure on the liquid crystal changes and it starts to close. With 4X, even when displaying a static image, if writing operations are always performed, electric power is required to keep the entire circuit connected at all times. For example, 2[10X
In order to print 60 pages per second on both sides of 200 pixels, a maximum frequency of approximately 2.5 M) Tz is required. This will dissipate a large amount of power.

It should be noted that it would be a pain if 60 images were to be scanned in 4 nanoseconds (4 nanoseconds), and this is necessary to drive the LCD with alternating current and avoid flickering. Furthermore, charging and discharging the capacitor.

It is true that there is a real need for an increase in power by bringing the cost closer.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an image display device that consumes less power and is suitable for displaying images that do not require halftones or still images.

The present invention will be explained below with reference to the drawings.

FIG. 2 shows an image display device of the present invention. A unit pixel is composed of a transmission transistor 5 formed in a semiconductor layer, a memory cell 6, (N selection circuit 7, and
, a liquid crystal cell 8, and an AC signal source 9.

11 ζ Here, it consists of 6 memory cells and flip-flops,
If the high voltage level signal is "1#" and the low voltage level signal is "01", then "if signal 11 is input, the output will be"
19 (Ichitake O') K + rat, then maintain the previous state until the 0M signal of 0# is input, and when the 09 signal is input, the output d O''('ftake 1 ' )
Vr-1? TS) #: h, it is a miracle if that state is maintained. In addition, the signal from the AC signal source 9 is input to the input of the signal selection circuit 7, and the output of the memory cell B is used as a control signal to selectively output a signal having the same phase as the input signal and a signal having the opposite phase. be. The output of the signal selection circuit 7 is connected to the pixel electrode 8α.

Now, the output of the AC signal source 9 is connected to the common electrical connection terminal 10, and when the output of the memory cell 6 is "11", the input and output of the signal selection circuit 7 are in reverse phase, and the output of the megalithic cell 6 is "01". The operation will be explained by taking as an example the case where the input and output of the signal selection circuit 7 are in phase.

First, each gate line xi, xiVc has a gate (Fil
When an angular and positive pulse is applied, the transmission gate (hereinafter TG, abbreviated as l-) is turned on,
Signal line? The image information applied to /i is input to the memory cell 6 through T5-G5, and the output of the memory cell 6 can be set to 0#f "19 times over" according to the image information. When the gate signal disappears, Te3 turns off, and the memory cell continues to hold the image information of "1f" or "Ow" until new image information is input next time. Similarly, if image information is written to the pixels on the side as iI, all pixels will continue to hold the currently held image information until new information is written, no matter how long the period is. In the pixel whose memory cell output is "11", the input and output of the signal selection circuit are in opposite phase, so the waveform of the AC signal groove, that is, the common electrode potential, and the output of the signal selection circuit, that is, the waveform of the pixel electrode, are as follows. When the power supply voltage is V, the alternating waveforms are of opposite phase as shown in FIG. Similarly, since the pixels have the same phase AC waveform as shown in FIG. 6B11a and 11c, no voltage is applied to the liquid crystal 8 as shown in 12b.

Therefore, images without halftones and their still images can be It is better to always display with less power.

l'j se'jc C-,) f, for still images, trust line ui, 1ti++--open and Kate life xi, 1%, zips.

Stop all driving times of xi+1...+j= l=
Therefore, if only the AC signal source 9 is operated, it tends to be white,
Since the frequency of the AC power source 9 is normally 311H2, the power consumption is completely reduced to zero. In addition, the method does not charge the signal to the capacitor, but basically controls the output of the memory cell without a current source, so there is no need to flow current through the signal line, so power consumption is significantly reduced. decrease. In addition, since this method applies an AC signal to the common electrode side as well, if the power supply voltage is V, applying an AC waveform of +■ to the liquid crystal will cause the power supply voltage to decrease compared to the voltage applied to the liquid crystal. It is possible to lower the voltage +□), which is praised for its reduction in power consumption. Also, 1) with a display without halftones.

Because there is a peripheral drive circuit and 1. - By configuring the entire information processing circuit with CMOB, it is possible to significantly reduce the power consumption of the entire system. Further, even if a TG is used as a switching element and the power supply voltage is reduced to a small value ζ, the high signal level of "1 #, /Jo#" is reliably higher than that obtained by inputting it to the memory cell.

FIG. 4 shows a specific example of the image display device of the present invention.

That is, using inverters 3 and 14 as a 7-lip flop for memory cells, the input and output terminals of inverter 3140 are connected to each other by Km, the input of inverter 3 is connected to the switching TG as the input of the memory cell, and the input terminal of inverter 4 is Let the output be the output of the memory cell. Then, using an exclusive OR (abbreviated as KOR) 15 as a signal selection circuit, the output of the twin inverter 4, that is, the output of the memory cell, is used as one input of the EOR circuit, and the output of the AC signal source 9 is used as one input of the EOR circuit. This is the input to the EOF1 circuit 150.

In addition to ζ, there is a part 1□ which connects the output of the KOR circuit 15 to the pixel electrode 8a. With this configuration, if the memory cell is set to "1", an AC voltage of ±V is applied to the liquid crystal, and the memory cell is set to "0". In this case, no voltage is applied to the liquid crystal, and the same operation as explained in FIG. 2 can be performed. Here, it is desirable to use CMOB inverters as the inverters 13 and 14 in order to reduce power consumption. FIG. 5 shows the ψ male side of the image display device of the present invention. Two TOl as signal j1 selection circuit
6,17 is used. The configuration of the memory cells connected to the inverters 13 and 14 is the same as the example shown in FIG.
The input terminal of the inverter 14 is i# connected to the P-channel side gate of TO16 and the n-channel side gate of TO17. Then connect the outputs of TOl6.17 to each other ii! i+ $F is connected to Tsubaki 8P, and the input terminal of TOl 7 is connected to a common electrode for all pixels, and connected to AC signal source 9. In other words, the input terminal of the TOl 6 is shared by all pixels and connected to the AC signal source 9 via an inverter 18.

With this configuration, the output of the memory cell is 71
When the value is 1, TOl6 is in the on state and TOl7 is in the off state, so AC voltages of 9- and 〈±V in Figure A of W3 are applied to the liquid crystal cell, and the output of the memory cell similarly becomes ``01''. When the voltage is applied to the liquid crystal cell,
! →No 1. In the examples shown in FIGS. 4 and 5, a KOR circuit and three Tes are used as signal selection circuits, but it goes without saying that the outputs of the memory cells are "19", "λ", and "Ov".
It is sufficient if the phase of the AC waveform applied to the pixel electrode of
Of course, these also fall within the scope of the present invention. Also, if the memory cell is “0#”
The circuit configuration to which an AC voltage of 2.+-.V is applied is exactly the same, and a description thereof will be omitted.

By using the image display device of the present invention, it is possible to obtain an image display device that consumes less power and is suitable for displaying images that do not require halftones and still images thereof. The goal is completely achieved. In other words, the circuit configuration must be entirely digital, and when displaying a still image, all peripheral circuits must be shut down except for the approximately 60 Hz AC No. 9 for driving the liquid crystal, which requires a large amount of overhead. The drop in power is eliminated. In addition, since the AC drive is adjustable regardless of the age of the display or the moving image, a display device with excellent longevity and reliability can be obtained. Therefore, by applying the present invention to character display devices such as characters and graphics using fine dots, it is possible to simultaneously achieve beautiful display using fine dots, low power consumption, long life, and high reliability. The industrial value of this invention is large stitches.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a conventional image display device, Fig. 2 is a circuit diagram showing an image display device of the present invention, and Fig. 3 shows a liquid crystal driver in the image display device of the present invention. -F explanatory drawing, FIG. 4 is a circuit diagram showing the p-body side of the image display device of the present invention, and FIG. 5 is a circuit diagram showing a specific example of 4b of the image display device of the present invention. To 1 5...Transmission gate 6...
・Memory self...Signal tooth selection circuit 8...Liquid crystal cell 8a...Pixel electrical connection 9...AC signal source 10...Common Electrode terminal 11a...Waveform of AC signal source 111)...Reverse phase AC waveform 11c...In-phase AC waveform 12a, 12b...Liquid crystal drive unit pressure Waveform 1
3.14... Inverter 15... Exclusive OR circuit 16.17... Transmission gate 18
...Inverter J] Nogami Applicant Daini Seikosha Co., Ltd.; I゛1'' Patent attorney Sekifue Mogami /
/″
f b 11 C 4 fig.

Claims (2)

[Claims] (1) Pixels are arranged in rows and columns on a semiconductor layer formed on an insulating substrate such as glass, or on a semiconductor substrate! In a double-image display device in which a transparent electrode is formed on a transparent substrate and is placed on the pixel electrode with a liquid crystal interposed therebetween as a counter electrode, When the output of one transmitter gate, one bit, one memory cell and the aforementioned e memory cell is ``19 level'' and ``0''
At the time of 9 level 1, a signal selection rotation is formed in the semiconductor layer to select AC waveforms for driving the liquid n1 whose phases are reversed to each other, and means for applying an AC waveform for driving the liquid crystal to the front Ie transparent camellia is also provided. An image display device characterized by comprising: (2) Previous Fii') One terminal of the transmission gate is connected to the Shinshichi supply line, the other terminal is connected to the input terminal of the previous P memory cell, and the first terminal of the transmission gate is connected to the input terminal of the previous e memory cell The output of the pixel electrode becomes a control signal for the pre-distribution signal selection circuit, and the output of the pre-i[1 signal selection circuit and the pixel electrode are connected to each other. 8F
image display device.