JPS6041023A - Optical modulating element - Google Patents

Abstract

PURPOSE:To provide high resolution to an optical modulating element which has liquid crystal between plural signal electrodes and row electrodes arranged facing the signal electrodes by arranging a light source on the substrate side of a light-shield mask provided to either of the signal electrodes and row electrodes. CONSTITUTION:Common electrodes 10 and 11 are applied with opposite-phase potentials all the time, and when the common electrode 10 and aperture parts A1 and A2 are selected optionally, the common electrode 11 and relative aperture parts A1' and A2' are turned off (shielded from light); and the common electrode 10 and relative aperture parts A1 and A2 are turned off and the common electrode 11 and relative aperture parts A1' and A2' are selected optionally to the contrary to write data on a drum alternately. In this case, there is some difference in finished copy picture quality according to whether the substrate 17 equipped with the metallic light shield mask 16 of a liquid crystal optical shutter is arranged on the side of the light source 17 or on an SELFOC side; no bleeding appears in a picture when the mask is arranged on the side of the light source, and the resolution is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical modulation element, and more particularly to an optical modulation element suitable for a liquid crystal-optical shutter capable of producing high-quality copies.

This liquid crystal-optical shutter is a liquid crystal electro-optical change! l
By using the old 2 technology, the modulators are arranged in a play pattern, irradiated with light from a light source, and the transmitted light is selectively emitted to respond to the luminescence solid image signal. A digital copy can be obtained by forming an optical signal and irradiating the optical signal onto a Lamiko photoreceptor.

The advantages of this liquid crystal-optical shutter array are: (1) When used in an electrophotographic printer, the printer device can be made smaller; (2) Polygons used in LBP (laser beam printer) There are no mechanically driven parts like scanners, so there is no noise, and there are fewer requirements for strict mechanical precision. Although it has these advantages, printers using this liquid crystal-optical shutter array are unable to sufficiently focus the optical signals transmitted through the apertures, and therefore the resulting dot images suffer from smearing. However, the resolution was low.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical modulation element suitable for a high-resolution photo printer.

Such an object of the present invention comprises a plurality of signal electrodes and at least one row electrode arranged opposite to the signal electrodes;
In the optical modulation element including a liquid crystal between the signal electrode and the row electrode, a t-mask is formed to block either the signal electrode or the row electrode, and the substrate side on which the light-shielding mask is provided is formed. This is achieved by an optical modulation element with a light source.

Hereinafter, the present invention will be explained with reference to the drawings. Figure 0, Part 1 is a plan view showing a part of the liquid crystal-optical shutter array of the present invention.

In embodiments of the present invention, a liquid crystal-optical shutter array having a time-division drive electrode structure as shown in FIG. 1 may be used. In the playback shown in FIG. 1, two rows of common electrodes 10 and 11 (indicated by dotted lines in the figure) are arranged on the g1 substrate, and two rows of common electrodes are arranged on the second substrate facing this. 10
and signal electrode 12 (12&, 12b
, 128°12a...) are arranged and φ. These common electrodes 10 and 11 and signal electrodes 12 (12a, 1
2b, 12Q.

12a...) are indicated by diagonal lines. These intersecting parts arranged in a zigzag pattern are
This can be referred to as an aperture of an optical shutter array, so it will be referred to as an aperture hereinafter.

In addition, in order to prevent light leakage from occurring at locations other than the opening, a light-shielding mask 16 made of metal is applied over the common electrode 10 as shown in FIG. 2.

Further, light can be shielded in the same way by preferably using an insulating material between the light shielding masks 16.

In this liquid crystal-optical shutter array, polarizing plates 19 and 19' are disposed on the outer sides of the first substrate 17 and the second substrate 18, respectively, and are in a crossed nicol state as shown by the arrows 13 and 14. The inner wall surfaces of the first substrate 17 and the second substrate 1B are such that the nematic liquid crystal having positive dielectric anisotropy sandwiched therebetween is initially aligned in the direction of arrow 15 (approximately 45 degree angle with respect to the polarization direction of the polarizing plate). Each of them is subjected to an alignment process such as a two-pin process so that they are oriented.

To simplify the following explanation, we will focus on the openings A and A2 corresponding to the common electrode 10 and the openings A, ′ and A2′ corresponding to the common electrode 11, and these openings A1 j
The operation in A2 #'1' and A2/ will be explained as an example.

A potential of opposite phase is always applied to the common electrodes 10 and 11, and when the common electrode 10 and the aperture are arbitrarily selected, the aperture associated with the common electrode 11 is turned off (light is blocked). Then, on the other hand, the openings associated with the common electrode 10 are turned off, and the openings associated with the common electrode 11 are arbitrarily selected, thus writing can be performed alternately on the drum.

Writing is performed using the above driving method, and copies are made when the substrate 17 equipped with the metal light-shielding mask 16 of the liquid crystal-optical shutter is placed on the light source 21 side and when it is placed on the SELFOC side. There was a difference in image quality.

That is, as shown in FIG. 2, the method of arranging the metal light shielding mask 16 on the side of the light source 21 resulted in less blurring on the image and improved resolution.

FIG. 2(b) is an explanatory diagram of a mode in which the shutter array 20 of the present invention is utilized in an electrophotographic printer. Second
In FIG. 1), the light source 21 is always on, and always illuminates the liquid crystal-optical shirt shirt 20. This shutter array 20 generates an optical signal by blocking the light beam from the light source 21 and making the selected area transparent by a liquid crystal drive circuit (not shown), and irradiates the photosensitive drum 22 with the optical signal. Light beams can be controlled. Further, in order to obtain a focusing property for the light beam from the light source 21 and the optical signal from the shutter array 20, it is desirable to arrange lenses 25 and 24 in the optical path. The photosensitive drum 22 is equipped with a strip equipped with a corona discharge device or the like in advance before being irradiated with an optical signal.
r′,,t.

The photosensitive drum 221C is charged positively or negatively at the station 25, and at a portion of the photosensitive drum 221C that is irradiated with light, the banded charge disappears and an electrostatic latent image is formed. The static 11L latent image formed in this manner is developed in the developing section 26 in the presence of a developer consisting of toner and carrier of the opposite polarity to the polarity at the time of charging, or in the case of an inverted IA image, the same polarity. The image is developed using a magnetic brush development method or the like while applying a pressure, and then transferred to an image holding member 28 (for example, paper) in a transfer section 27, and then fixed by heat or pressure in a fixing section 29 to be completely fixed. A printed product is obtained.

The photoreceptor that receives the optical signal generated from the shutter array 20 is not limited to the electrophotographic type described above, but also, for example, a silver halide photoreceptor (e.g., monochrome paper, color paper, 3M's Dry Silver ”, etc.).

[Brief explanation of the drawing]

FIG. 1 is a plan view of the structure of the electrode part used in the optical modulation element of the present invention. FIG. 2(a) is a sectional view of the optical modulation element of the present invention. FIG. 2(1)) is an explanatory diagram showing a mode in which the optical modulation element of the present invention is applied to an electrophotographic printer. 10.11... Common electrode 12... Signal electrode 13.14... Polarization axis 15... Rubbing direction 16... Metal light shielding mask 17... First substrate 18... - Second substrate 19 , 19'...Polarizing plate 21...Light source agent Patent attorney Gi Marushima-1□(II ・Electronic Φ

Claims (1)

[Claims] In an optical modulation element, the optical modulation element has a plurality of signal electrodes and at least one row electrode disposed opposite to the signal electrodes, and a liquid crystal is provided between the signal electrodes and the row electrodes. An optical modulation element characterized in that a light-shielding mask is formed on any one of the ten thousand electrodes, and a light source is provided on the substrate side on which the light-shielding mask is provided.