JPS59111130A - Optical shutter element - Google Patents

Abstract

PURPOSE:To increase the vignetting factor of an optical shutter part and to facilitate the mounting of each driving circuit and connections of elements by forming an optical shutter array zigzag so that >=2 lines are obtained in parallel or a plane. CONSTITUTION:An optical shutter element 43 sandwiched between a polarizer and an analyzer have optical shutter parts zigzag. Only specific part of light from a light source 44 is transmitted by the optical shutter element 43 to form an image on the surface of a photosensitive drum 41. Therefore, the optical shutter element 43 write a pattern at every other point and then writes patterns of the remaining points with delay synchronously with the rotation of the photosensitive drum 41. Consequently, the shutter part is made large even when the resolution is equal. Namely, the vignetting factor of the shutter parts is increased and the mounting of each driving circuit and connections of elements are facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solid state optical shutter element that can be used as a writing device for an optical printer.

Conventional Structures and Problems In recent years, with the development of small computers, automation has become increasingly common in various fields, and the field of information processing technology has attracted much attention. Printers as information output devices are also devices that play a very important role, and various printers are currently being developed. Among them 1c
Of these, non-impact printers are attracting the most attention, and optical shutters that use solid-state electro-optic effects can also be used as writing devices. the current.

What is known as the above-mentioned optical shutter element is La
An electric field generated when a voltage is applied to a substrate with a plurality of strip-shaped electrodes symmetrically arranged on the front and back or on at least one side of a plate made of transparent porcelain such as titanic acid or lead zirconate (PLZT). ±46° to the direction of the vector
It has a structure in which it is sandwiched between polarizing plates having two polarizing axes.

A conventional optical shutter element will be described below with reference to the drawings.

FIG. 1 shows an example of a configuration diagram of a conventional original shutter element, in which 11 is a PLZT plate, 12 is a common electrode provided on the PLZT flat plate 11, and 13 is a group of voltage application electrodes. be. Reference numeral 14 denotes a polarizer, and a 15 iJ detector, which has a polarizer in the direction of ±45° with respect to the direction of the electric field vector generated when a voltage is applied between the common electrode 12 and the voltage application electrode 711. It is configured. The operation of the optical shutter element configured in this way will be explained below.

When light is irradiated from the light source 16 provided at the rear of the polarizer 14 in FIG. , birefringence due to the electro-optic effect does not occur, and the polarizer 13. The light is blocked by the analyzer 15, but when a voltage is applied to the voltage application electrode group 13, birefringence occurs due to the Kerr effect of the electro-optic effect, the polarization state of the light changes, and the light is transmitted. do. Therefore, by applying a voltage to any electrode in the voltage application electrode group 13, light from any part can be transmitted, and by placing a photoconductor or the like in front of the analyzer 15, any pattern can be created. It can be used as a writing head for non-impact optical printers.

By the way, writing heads currently used in printers, etc. are required to have a resolution of at least 1o line/M or more, and when using the solid-state optical shutter array mentioned above, a resolution of 2Qyn or more is required. A long optical shutter head is required. However, in the conventional configuration shown in FIG. 1, in order to have a resolution of 10 lines/5 tir, each electrode must be formed with a width of about 2Q μm. -! In addition, since light does not pass through the electrode portion, the aperture ratio (area ratio occupied by the light transmitting portion in a portion of each light shutter) of a portion of each light shutter is approximately 50%, which considerably limits the amount of transmitted light. Furthermore, at present, there is no long solid porcelain that has the electro-optic effect, so when using it as a printer head, each element must be connected, but in the conventional configuration, teeth,
Very high precision is required for connection.

As mentioned above, when using the optical shutter element as a writing head in a printer, the conventional configuration has drawbacks such as mounting problems, processing problems, and a poor aperture ratio in a part of the optical shutter. have.

OBJECTS OF THE INVENTION The object of the present invention is to increase the aperture ratio of a part of the light/Yatter element when using the light distribution NOYANOTER element as a writing head of a printer, etc. It is an object of the present invention to provide an optical/diameter element that can be easily mounted with a drive unit for use with other devices, and can also simplify connections between elements.

Structure of the Invention The optical shutter element of the present invention is capable of forming two or more parallel optical shutter rows on at least one main surface of a flat transparent substrate having Kerr effect or Pockels effect as an electro-optical effect. A plurality of counter electrodes are provided on the
and a portion of each shutter of the two or more shutter rows,
The plurality of opposing electrodes are arranged so as not to overlap each other on a line perpendicular to the shutter row, thereby increasing the aperture ratio of a part of the original shutter, and increasing the aperture ratio of the light shutter element and the voltage application drive section. This simplifies the mounting and connection between optical shutter elements and is effective for use in writing to optical swanters and the like.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a block diagram of the original shutter element in the present invention. In FIG. 2, 21 is a PLZT flat plate, 22 is a common electrode placed on two P L Z TXF plates, and 23 is a group of electrodes for voltage application. 24 is a polarizer, 25 is an analyzer, and has a polarization axis in the direction of ±45 with respect to the direction of the electric field vector generated when a voltage is applied between the common electrode 22 and the voltage application electrode group 23. It is configured.

The operation of the optical shutter element of this embodiment configured as described above will be explained below.

When light is irradiated from the light source 26 provided at the rear of the polarizer 24 in FIG. 2, when a voltage is applied to the voltage application electrode group 23, birefringence occurs due to the Kerr effect of the electro-optic effect.
The source of that part is transparent. Figure 3(a), [with]) is
This figure shows a comparison of the original shutter action between the embodiment of the present invention shown in FIG. 2 and the conventional configuration shown in FIG. 1.

FIG. 3(a) is a schematic diagram showing an electrode structure of a conventional configuration, and FIG. 3(b) shows an electrode structure in an embodiment of the present invention. For example, in the conventional configuration shown in FIG. 3(a), when a voltage is applied to electrodes A and B in the voltage application electrode group 13, light in the shaded area in FIG. 1 is transmitted. On the other hand, in the configuration of the present invention shown in FIG. 3(b), when a voltage is applied to the C and D electrodes, light in the shaded area in the figure is similarly transmitted. As described above, the light shutter effect in the conventional structure is such that some of the light shutters are lined up in a row, but in the embodiment of the present invention,
The light shutters are not arranged in a row, but in a staggered pattern.

FIG. 4 shows the overall configuration of an optical shirttal element according to an embodiment of the present invention when used as a writing head of an optical printer, in which 41 is a photosensitive drum, 42 is a selfoc lens array 43, and FIG. In an optical shutter element sandwiched between a polarizer and an analyzer according to an embodiment of the present invention, some of the optical shutters are arranged in a staggered manner. Further, 44 indicates a light source, the light from the light source 44 is transmitted only in a specific part by the optical shutter element 43, and the transmitted light is transmitted through the selfoc lens 42.
As a result, an image is formed on the photosensitive drum 41 -F. Therefore, the optical shutter element according to the present invention does not form dots in a line on the surface of the photoreceptor drum and write an arbitrary pattern on the surface of the photoreceptor drum as in the conventional method, but writes a pattern every other point on the photoreceptor drum 41. The pattern of the remaining points is written with a delay according to the rotation of the point.

Therefore, one drive section of the optical/diameter element requires memory elements for two to three lines, but the required capacity is less than I Kbit, and some of the shattered optical shutters become staggered. Therefore, defocusing on the surface of the photoreceptor drum will not be a problem at all if the total distance below -F of the part of the optical shutter with the staggered structure is set to one skin or less.

Therefore, with such a configuration, as is clear from FIG. 3, even if the resolution is the same, a portion of the optical shutter can be made larger. In other words, the aperture ratio of a portion of the optical shutter increases. Furthermore, the width of the common electrode section can be reduced to a minimum, making manufacturing easier, and the occurrence of disconnections in the electrode section is extremely reduced, greatly improving the reliability of the device. In the embodiment of the present invention, the electrode width of the voltage application electrode group 23 is set to 4oμ.
m, and the electrode interval between the voltage application electrode group 23 and the common electrode 22 was 30 μm. Therefore, in this embodiment, the aperture ratio at one point in the optical shutter is 60%, but it is possible to increase the aperture ratio by reducing the electrode width of the voltage application electrode group 23.

Moreover, although Cr-Au and ITO electrodes were used as electrode materials, other electrode materials may be used.

As described above, according to this embodiment, the optical shutter arrays are not formed in one row as in the conventional case, but are formed in a staggered manner, and the aperture ratio of a part of the optical shutters is increased, and the element This realizes a highly reliable original shutter element that is easy to manufacture and integrate with an external drive circuit.

Effects of the Invention As is clear from the above explanation, the present invention comprises forming an optical shutter array by forming a plurality of electrodes on a flat transparent substrate having an electro-optic effect such as PLZT, and By forming the optical shutter arrays on the above-mentioned flat plate in a staggered manner so that each row has two or more rows in parallel, the aperture ratio of a part of each shutter can be increased, and the mounting with the driving circuit of each part and the manufacturing of the elements can be facilitated. An excellent effect can be obtained. This also means that the resolution of the optical shutter array can be made larger than before, and as the printing quality of printers and the like continues to improve, the effects of the present invention are significant.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the overall structure of a conventional optical shutter element, FIG. 2 is a perspective view showing the overall structure of an optical shutter element according to an embodiment of the present invention, and FIGS. 3(a) and (b)
4 is a front view of the electrode structure of a conventional optical shutter element and an optical shutter element according to an embodiment of the present invention, and FIG. 4 is an overall configuration when the optical shutter element according to the present invention is used as a writing head of an optical link. It is a diagram. 21... PLZT flat plate, 22... common electrode,
23... Voltage application electrode group, 24... Polarizer, 25... Analyzer, 41... Photosensitive drum,
42... SELFOC lens array, 43...
... Former shutter element, 44 ... Light source. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2rI! J 6 Figure 3 2

Claims (1)

[Claims] A plurality of opposing electrodes are provided so that two or more parallel rows of light shutters are formed on at least one main surface of a flat transparent substrate having a Kerr effect or a Pockels effect as an electro-optic effect, and An optical shutter element characterized in that the plurality of opposing electrodes are arranged so that a portion of each shutter of the two or more shutter rows does not overlap with each other on a line perpendicular to the shutter rows.