JPH03204615A - Magnetooptic element and display device using the same - Google Patents

Abstract

PURPOSE:To enlarge, project, and display an image with small power consump tion by providing X-array transparent electrodes and Y-array transparent electrodes, which are so arranged as to form matrix intersections, while interpos ing a transparent electrostrictive dielectric film. CONSTITUTION:This device is equipped with a transparent magnetic film 1 which has uniaxial magnetic anisotropy, the transparent magnetostrictive dielec tric film 5 which is arranged nearby the transparent magnetic film 1 so that the film 1 is stressed, and the X-array transparent electrodes 4 and Y-array transparent electrodes 3 which are arranged while interposing the transparent electrostrictive dielectric film 5 as to form the matrix intersections. Then a voltage is applied to a part of the transparent electrostrictive dielectric film 5 corresponding to one picture element to strain the transparent electrostrictive dielectric film at the part. Thus, the voltage is only applied to the transparent electrostrictive dielectric film 5, so the power consumption is extremely low. Consequently, the low power consumption and performance of the high-definition, large-screen projection type display device can be improved.

Description

[Detailed Description of the Invention] [Summary] The purpose of this invention is to perform light switching and enlarged projection display by performing magnetization reversal with small power consumption in magneto-optical elements and display devices using the same. A transparent magnetic film having anisotropy, a transparent dielectric film disposed in close proximity to apply stress to the transparent magnetic film, and a matrix intersection point with the transparent electrostrictive dielectric film sandwiched therebetween. A magneto-optical element is configured to include at least X-column transparent electrodes and Y-column transparent electrodes arranged to form
A display device is constructed so that a voltage is applied to the column transparent electrodes and the Y column transparent electrodes, and the matrix intersections are used as pixels to control the ON/OFF of light, thereby enlarging and projecting the image onto the screen.

[Industrial application field]

The present invention relates to a display device using a magneto-optical element, and particularly to a projection type display device that performs high-speed optical switching with low driving power, and is capable of large-capacity gradation display.

[Conventional technology]

Conventionally, a wide variety of products have been put into practical use as display devices, including CRTs. Recently, flat panel displays such as plasma displays (FDPs) and liquid crystal displays (LCDs) have come into widespread use due to the demand for smaller and lighter displays.

FDPs have high brightness and brightness, but require high voltage and high power consumption, while LCDs have the characteristics of low voltage and low power consumption, but have low contrast and still have problems in terms of definition and large screens.

In response, a proposal has been made to obtain a projected image on a screen using a magneto-optical element.

For example, FIG. 6 shows an example of a conventional magneto-optical element, in which (a) is a perspective view and (b) is a cross-sectional view of XX. magnetic carnet G
a3GasO+□(GGG), 1" is a transparent magnetic film, for example, a magnetic Carnet film having uniaxial magnetic anisotropy formed on the transparent substrate 2 by liquid phase epitaxial method (LPE), and 4' is a X formed on the transparent magnetic film l'
In the column electrode, for example, a striped transparent conductor wiring, 3
' is a Y-column electrode arranged to intersect with the X-column electrode 4' with an insulating film 9 in between to form a matrix intersection, and is also made of striped transparent conductor wiring, for example. 30 is an X drive control circuit for passing a current 11 through the X-column electrodes, and 30 is a Y-drive control circuit for passing a current i through the Y-column electrodes 3.

Now, bias magnetic field applying means 13, not shown here.
．． For example, a bias magnetic field is applied to a transparent magnetic film 1 having uniaxial magnetic anisotropy using a permanent magnet to align the direction of magnetization in one direction, for example, downward.

Therefore, for example, a current i is applied to the third X-column electrode 4'3.
When a current i is applied to the second 7-column electrode 3''2,
Magnetization reversal occurs at the intersection indicated by the crosshatch, and when the transmitted light is observed between the orthogonal nicols, the so-called Faraday effect causes the section indicated by the crosshatch to
For example, a dark area is identified within a bright area. In other words, a high-density XY matrix optical switch array is constructed.

FIG. 5 is a diagram showing an example of a display device using a conventional magneto-optical element. In the figure, 100 is the conventional magneto-optical element explained in FIG. is a collimating lens,
15 is a magnifying projection lens system, and 17 is a screen.Usually, the size of the transparent magnetic film I" is several tens of square meters or less at most, and it cannot be used as a display device for the time being. Since minute pixels can be formed at a high density, a display device with a large screen and a large capacity can be constructed by enlarging and projecting the image onto a screen as shown.

[Problem to be solved by the invention]

However, the conventional magneto-optical device described above consumes a lot of power because it uses the so-called current access method, in which current is passed through two orthogonal conductor wires, to reverse the magnetization direction that constitutes the optical switch. (, also, the transparent magnetic film 1'
There were problems such as unstable operation due to temperature rise, and a solution was needed.

[Means to solve the problem]

The above problem consists of a transparent magnetic film 1 having uniaxial magnetic anisotropy, a transparent electrostrictive dielectric film 5 disposed close to the transparent magnetic quasi-film 1 so as to apply stress, and a transparent electrostrictive dielectric film 5 that The magneto-optical element 10 is configured to include at least the X-column transparent electrodes 4 and the seventh-column transparent electrodes 3, which are arranged to form matrix intersections with the magnetic dielectric film 5 in between. This magneto-optical element 10, an X drive control circuit 40 and a Y drive control circuit 30 for applying voltages to the X row transparent electrode 4 and the seventh row transparent electrode 3, and the transparent magnetic film 1
Bias magnetic field applying means 13 for applying a perpendicular magnetic field to the surface
, two polarizing plates 11 and 12 arranged orthogonally on both sides of the magneto-optical element IO, a light source 16 arranged in front of one of the polarizing plates 11, and a light source 16 that directs the light from the light source to the magneto-optical element IO. a collimating lens 14 that allows the parallel light to be incident on the magneto-optical element IO; This problem can be solved by configuring the display device to include at least the screen 17 located at the rear.

[Effect]

According to the present invention, a voltage is applied to a portion corresponding to one pixel of the transparent electrostrictive dielectric film 5 which is arranged close to the transparent magnetic film 1 so as to apply stress, and the transparent electrostrictive film 5 of the transparent magnetic film 1 is This causes distortion in the dielectric film. Due to the distortion, local parts of the transparent magnetic film l that are close to each other.

In other words, stress is applied to the portion corresponding to the pixel. It is already well known in magnetic bubble memory technology that if a specific magnetic Carnet film, for example, is selected as a transparent magnetic film, magnetization reversal or magnetization rotation will occur due to stress applied to the magnetic film. Since it is only necessary to apply a voltage to the transparent electrostrictive dielectric film 5, the power consumption is extremely small, and the degree of magnetization rotation can be controlled by the degree of electrostriction, that is, the magnitude of the applied voltage. This allows for gray display.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention, in which (a) is a plan view and (b) is a sectional view taken along line xx'.

In the figure, ■ is a transparent magnetic film, and the size is IOm m x lo
For example, on a transparent substrate 2 made of GGG with a thickness of 0.5 mm and a thickness of 3 μm, a B! 2.5DYo5Gao
, 5Fe4□012 is formed by sputtering at a substrate temperature of 550°C.

Next, a transparent electrostrictive dielectric film 5 is placed on the transparent magnetic film l.
For example, a well-known PLZT ceramic film is deposited to a thickness of 1 μm by sputtering.

Next, on the transparent electrostrictive dielectric film 5 and on the transparent substrate 2, a transparent conductive film, for example, ITO (In203Sn0
2) is formed to a thickness of 500 nm, and strip-shaped X-Y matrix electrode wiring having a width of 50 μm and a cap of 10 μm is formed so as to be orthogonal to each other.

In this example, the configuration is such that 150 X column electrodes and 150 Y column electrodes constitute a total of 150×150 pixels.

30 is a Y drive control circuit for driving and controlling the seven rows of transparent electrodes 3;
Reference numeral 40 denotes an X drive control circuit that drives and controls the X-column transparent electrodes 4.

Now, for example, by aligning the magnetization direction of the transparent magnetic film 1 downward using a bias magnetic field applying means (not shown), the third X-row transparent electrode 43 and the second 7-row transparent electrode 3 are aligned. When a voltage is applied from the X drive control circuit 40 and Y drive control circuit 30 to □, the intersection point, that is,
Distortion occurs in the transparent electrostrictive dielectric film 5 in the portion indicated by A, and the magnetization of the transparent magnetic film l in that portion is reversed, so to speak, so that information is written.

At this point, information is written on it, but it is not used as a display device (since it is not used as a display device), it can be made into a practical device by constructing it as a projection type display device.

FIG. 2 is a diagram showing an example of the configuration of a display device using an example element of the present invention. In the figure, 10 is a magneto-optical element of the present invention. As the light source 16, for example, a halogen lamp may be used, and as the bias magnetic field applying means 13, a permanent magnet or an electromagnet may be used. The same reference numerals will be given to the same parts, and the explanation of the equivalent parts will be omitted.

FIG. 3 is a diagram for explaining the basic operation of the embodiment of the present invention, and schematically shows the operating characteristics when polarizing plates are orthogonally arranged on both sides of the element of the embodiment of the present invention. The vertical axis represents the transmitted light intensity, and the horizontal axis represents the voltage applied between the X and Y column transparent electrodes. Further, the arrows (■ to ■) shown at the bottom of the figure indicate changes in the direction of magnetization of the transparent magnetic film l as voltage is applied. That is, the magnetization direction rotates, for example, clockwise, with the applied voltage, and the transmitted light intensity changes from dark-gray-bright to gray-dark correspondingly. Therefore, by enlarging and projecting this, a projection type display device capable of displaying gradations can be obtained. In this figure, the magnetization is illustrated for a case of 90° rotation.

FIG. 4 is a diagram showing another embodiment of the present invention.

In the embodiment, one striped electrode, e.g.
Although the Y-column electrodes 3 were formed with the transparent substrate 2 in between, in the embodiment of the present invention, the 7-column electrodes 3 and the X-column electrodes 4 are directly formed on both the upper and lower surfaces of the transparent electrostrictive dielectric film 5. The driving voltage can be reduced by that amount.

The embodiments described above are merely examples, and it goes without saying that preferred materials and configurations, or combinations thereof, can be used as appropriate, as long as they comply with the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, a voltage is applied to a portion corresponding to one pixel of the transparent electrostrictive dielectric film 5 which is arranged closely to apply stress to the transparent magnetic film l. This causes distortion in the transparent electrostrictive dielectric film in that part. The distortion can apply stress to a local part of the transparent magnetic film l in the vicinity, that is, a part corresponding to a pixel, and cause magnetization reversal or magnetization rotation of the transparent magnetic film in that part.

Moreover, since it is only necessary to apply a voltage to the transparent electrostrictive dielectric film 5, the power consumption is extremely small, and the degree of magnetization rotation is the same as that of electric distortion.

That is, by controlling the magnitude of the applied voltage, gray display is also possible, which greatly contributes to lower power consumption and improved performance of high-definition, large-screen projection display devices.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing an example of the configuration of a display device using an example element of the present invention. FIG. 3 is a diagram explaining the basic operation of the embodiment of the present invention. , FIG. 4 is a diagram showing another embodiment of the present invention, FIG. 5 is a diagram showing an example of a display device using a conventional magneto-optical element, and FIG. 6 is a diagram showing an example of a conventional magneto-optical element. It is. In the figure, l is a transparent magnetic film, 2 is a transparent substrate, 3 is a Y-column transparent electrode, 4 is an X-column transparent electrode, 5 is a transparent electrostrictive dielectric film, IO is a magneto-optical element, 1112 is a polarizing plate, 13 is a bias magnetic field applying means, 14 is a collimating lens, 15 is an enlarged projection lens system, 16 is a light source, 17 is a screen, 30 is a Y drive control circuit, and 40 is an X drive control circuit. , JOX le Kankei 4p standing road (b) Figure 3 1 Figure 3 1 Figure showing the actual color division 1 element and display device world, figure showing precedents ΣL The next nine months old figure diagram This invention I Fi Nanao Atsumi 8th part 1 Iku 1 Rei Hide rgo diagram

Claims (2)

[Claims] (1) a transparent magnetic film (1) having uniaxial magnetic anisotropy; a transparent electrostrictive dielectric film (5) disposed close to the transparent magnetic film (1) so as to apply stress to the transparent magnetic film (1); A magneto-optical element comprising at least X-column transparent electrodes (4) and Y-column transparent electrodes (3) arranged to form matrix intersections with a transparent electrostrictive dielectric film (5) in between. . (2) The magneto-optical element (10) according to claim (1), and the X-column transparent electrodes (4) and Y-column transparent electrodes (4) of the magneto-optical element (10).
Applying a perpendicular magnetic field to an X drive control circuit (40) and a Y drive control circuit (30) for applying voltage to the column transparent electrodes (3), and to the surface of the transparent magnetic film (1) of the magneto-optical element (10). Bias magnetic field applying means (13) for applying two polarizing plates (13) disposed orthogonally on both sides of the magneto-optical element (10).
1, 12), and a light source (1) disposed in front of the one polarizing plate (11).
6), a collimating lens (14) that causes the light from the light source to enter the magneto-optical element (10) as parallel light; ); and a screen (17) disposed behind the magnifying projection lens system (15).