JPS6011821A - Liquid crystal shutter - Google Patents

Abstract

PURPOSE:To enhance responsiveness of a device and to simplify it by utilizing the high speed responsiveness and memory function of the SmC phase or SmC* phase of smectic liquid crystals and using the dot to be scanned at the same time as one block unit to reduce a number of drivers and their connections. CONSTITUTION:A liquid crystal shutter consists of polarizing plates 41, 45, a transparent base 42 provided with transparent electrodes 47 corresponding to dots, transparent bases 44 provided with plural blocks of solid transparent electrodes 49, and smectic liquid crystals 43 having high-speed responsiveness filled in a space formed with a spacer 46. The liquid crystals of the liquid crystal shutter are driven by utilizing the memory function of the SmC phase or SmC* phase, using the transparent solid electrode 49 as one block unit to divide the shutter into plural blocks. A number of the drivers necessary for driving all the transparent dot electrodes 47 is only a number corresponding to the electrodes 47 contained in one block, and used in common in each block. The electrode 49 in each block is externally connected through an independent lead. As a result, the device can be enhanced in responsiveness and simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal shutter that uses the high-speed switching characteristics and memory effect of smectic liquid crystal to simultaneously achieve increased speed and simplified drive implementation.

In recent years, with the advanced development of displays, it has become desirable for printers to be able to output high-speed, multi-color output.

Under such circumstances, various types of printers have been announced, but the method that can still be said to be definitive is the % type.Color type using heat transfer.The one-sided type requires synchronization of the transfer film, which makes it difficult to increase the speed. Although the inkjet method is superior in multicolor printing, it is similarly slow. In the electrophotographic method, the structure becomes large even at high speed. In particular, in the electrophotographic method, conventionally, in order to irradiate light, a laser beam is scanned by a rotating mirror such as a polygon and applied onto a photoreceptor drum. This method not only complicates the structure due to the laser, mirror, and lens system, but also inevitably increases the size of the structure.

Furthermore, in order to realize a compact electrophotographic device, a method using a liquid crystal shutter without using a laser system has been announced. However, the conventional method using a liquid crystal shutter is very slow in terms of speed because it uses a nematic liquid crystal, and due to drive characteristics, all dots must be independently connected to the driver's foot, which is difficult to implement. This is also unfavorable, and the desired compactness and cost reduction have not been achieved.

The present invention overcomes the above drawbacks and realizes a compact electrophotographic printer.The key point of the present invention is to use a smectic liquid crystal with high-speed response as the liquid crystal.
In order to increase response speed and simplify mounting, the SmO phase of the smectic liquid crystal, S m O
*Using the phase memory property, the dots that are simultaneously scanned are made into blocks, greatly reducing the number of drivers and their connections.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a configuration diagram illustrating the configuration of a portion where a latent image is formed in an electrophotographic method using the liquid crystal shutter of the present invention. 1 is a light source and a photosensitive drum 5 on which a photoconductor is formed;
It has a wavelength that matches the characteristics of Generally, a fluorescent light is sufficient.

2 is a reflecting plate that reflects the light from the light source 1. Reference numeral 3 denotes a lens array for condensing light from a light source onto the photoreceptor drum 5, which is a cell-hoc lens array. 4 is a liquid crystal shutter of the present invention, which turns off the light irradiated from the light source 1 by 5N in accordance with the data pattern;
The light passed through the photoreceptor drum 5 is irradiated onto the photoreceptor drum 5 to form a latent image. Around the photosensitive drum 5, of course, there are provided a corona charge forming section, a toner developing section, a paper transfer section, a cleaning section, etc. necessary for electrophotography. 5 is a photoreceptor drum, and Be,
A thin layer of photoconductive material such as 0 (121) is formed.

FIG. 2 is an external view explaining the present invention in detail. 41 is a polarizing plate, 42 is a transparent substrate such as glass on which a dot-compatible transparent electrode is formed, and 43 is a smectic liquid crystal. 44 is a transparent substrate made of glass or the like on which a plurality of blocks of solid transparent electrodes are formed, and 45 is a polarizing plate corresponding to 41. 46 is a spacer for forming a cell, and the cell thickness is about 1 to 6 μm, which is quite thin.
P, /1. FIG. 3 is an enlarged view of a transparent substrate 42 made of glass or the like on which dot-corresponding transparent electrodes are formed.

A transparent electrode 47 corresponds to each dot, and is made of tin or indium by vapor deposition. The size of one dot can be made quite small using this method. In order to achieve a resolution of 16 lines/mm, it is sufficient to form a negative electrode with a thickness of approximately 060 μm. 48 is a lead to each dot' electrode.

FIG. 4 is an enlarged view of a transparent substrate 44 on which a plurality of blocks of transparent solid electrodes are formed. Reference numeral 49 denotes a transparent solid electrode corresponding to each block, which is formed of tin or indium by vapor deposition. 50 is a lead to each transparent solid electrode.

FIG. 5 is an explanatory diagram of a method of totally reducing the number of drivers and the number of external connections according to the present invention. The liquid crystal drive of the liquid crystal shutter of the present invention is performed by dividing the transparent solid electrode 49 into approximately 1jli blocks into several blocks. Essential for driving the fully transparent dot electrode 47! The number of drivers 61 corresponds to the number of transparent dot electrodes included in one block, and is shared between each block.

In addition, the transparent solid electrodes of each block are externally connected with independent leads. Therefore, when driving each dot, only the dots selected by the driver using the transparent T/I dot electrodes included in one block of transparent solid electrodes and to which a voltage is applied are turned ON, and polarization characteristics appear, and the upper and lower dots It is formed so as to turn on the transmission in cooperation with two polarizing plates. To drive the dots facing the next block, select the next block of the transparent solid electrode, select the facing transparent dot electrode with a driver, apply voltage, and drive the selected dot. The transparent dot electrodes are connected separately to the legs of each driver within the same block, but are connected to a common leg between blocks.

The reason why it can be driven in blocks as described above is because the smectic liquid crystal has memory properties. In other words, 1
OIJ, 0TI of dots selected in block units
I' can hold the selected optical state until the entire block has been scanned and the next selection is made. Therefore, since there is no need to constantly scan and drive each dot, it is possible to drive it by dividing it into blocks, greatly reducing the number of external connections and drivers, and making it possible to reduce the number of external connections and drivers. This eliminates the complexity of implementation. This is a point that could not be achieved with conventional liquid crystal shutters using nematic liquid crystals.

The present invention uses a smectic liquid crystal with a response speed of about 100 μS, which enables a very high-speed printer.It is also easy to implement because it uses memory, and is compact and inexpensive. It is possible to provide a photographic printer, and its industrial and bicultural significance is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the configuration of the application of the present invention to an electrophotographic method, Fig. 2 is an external view explaining the invention in detail, and Fig. 3 is an enlarged view of a transparent substrate forming transparent electrodes corresponding to dots. The plan view, FIG. 4 is an enlarged plan view of a transparent substrate on which transparent solid electrodes corresponding to blocks are formed, and FIG. 5 is an explanatory diagram showing the driving and connection relationship of the present invention. 4...Liquid crystal shutter 41.45...Polarizing plate 42.44...Transparent substrate 43...Smectic liquid crystal 47...Dot compatible Transparent electrode 49...
・Transparent peta electrode 61 compatible with blocks...

Claims (1)

[Claims] In a liquid crystal shutter for forming a latent image on a photoreceptor in a printer using electrophotography, multiple blocks of transparent solid electrodes are formed on one transparent substrate, and transparent electrodes corresponding to individual dots are formed on the other transparent substrate. A cell is formed by providing several dots of , a polarizing plate is provided on the outside of both transparent substrates, a smectic liquid crystal is sealed in the cell, and a voltage is applied to the 8mC phase or the 8mO* phase. The polarization properties of the dots work together with the polarizing plate to act as a light shutter, and the dot-compatible electrodes are simultaneously driven for each block divided by solid electrodes, and the memory effect of the liquid crystal is used to create a light shutter for each block that has already been driven. A liquid crystal shutter characterized in that all blocks are driven by sequentially driving the blocks while maintaining the state.