JP2594848Y2 - Display device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device suitable for a portable computer such as a book-type personal computer.

[0002]

2. Description of the Related Art As is well known, various liquid crystal displays composed of liquid crystal display elements have been developed. This liquid crystal display is suitable for forming a thin and lightweight display device, and has been used for calculators, digital watches and the like for some time. Recently, with the remarkable progress of liquid crystal technology,
Various high-performance liquid crystal displays have been put to practical use. As a result, portable computers such as a book-type personal computer using a liquid crystal display have become widely used, and many businessmen and the like who use them in trains and the like have come to work.

[0003]

By the way, the information displayed on the display device such as the above-mentioned portable computer often has high confidentiality which is difficult to be seen by a third party other than the user. Absent. However, in a display device used for a conventional portable computer or the like such as a liquid crystal display, there is a problem in that it is difficult for a person other than the user to pry at the display information, and that confidentiality is difficult to maintain.

The present invention has been made under such a background, and has as its object to provide a display device in which a third party other than the user cannot view the display information.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a display means for displaying information and emitting display light according to the information;
A polarizing means for polarizing only the light, and unpolarized light corresponding to white light in a second polarization direction perpendicular to the first polarization direction, and superimposing it on the display light polarized by the polarization means. And a light analyzing means mounted on a user for extracting the display light by polarizing the combined light in the first polarization direction.

[0006]

According to this invention, after displaying information and emitting display light corresponding to the information, the polarizing means polarizes the display light only in the first polarization direction. Then, the combining means polarizes the unpolarized light corresponding to the white light in a second polarization direction perpendicular to the first polarization direction, and superimposes the light on the display light polarized by the polarization means to combine. Generate light. Further, an analyzing unit polarizes the combined light in the first polarization direction to extract the display light. As a result, a third party other than the user sees the combined light directly, and cannot recognize the display information.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a display device according to an embodiment of the present invention. In this figure,
Reference numeral a denotes a display including a liquid crystal display element (LCD), a CRT, and the like, which emits non-polarized (unbiased) display light (hereinafter, referred to as display light) La for displaying character information or graphic information. . b is a white light source arranged in parallel with the display a, and generates white light Lb which is parallel to the display light La and has no bias.

Further, c and d are polarizers for linearly polarizing the display light La and the white light Lb, respectively, and are arranged such that their respective polarization planes are at right angles to each other. That is, the polarizer c polarizes the display light La emitted from the display a in the predetermined direction X, while the polarizer d polarizes the white light Lb emitted from the white light source b at right angles to the polarization direction X of the polarizer c. In the direction Y. However, when a display that emits polarized display light is used, as is often seen in a liquid crystal display, the polarizer c can be omitted.

Further, e is a half mirror, and a polarizer c
Is disposed in the optical path of the linearly polarized light La ′ such that the mirror surface is at 45 ° with respect to the direction of travel of the linearly polarized light La ′ of the display light La via the optical axis. The half mirror e reflects the linearly polarized light La ′, changes its traveling direction to a right angle direction, and transmits the linearly polarized light Lb ′ (described later) incident on the back surface to the mirror surface side.

Reference numeral f denotes a mirror, which is disposed in the optical path of the linearly polarized light Lb 'so that the mirror surface is at 45.degree. With respect to the traveling direction of the linearly polarized light Lb' of white light via the polarizer d. Are parallel. This mirror f reflects the linearly polarized light Lb ', and makes the traveling direction thereof bend at a right angle to be incident on the half mirror e.

[0011] Further, g is an analysis spectacles worn by the user, and converts the combined light La'b 'of the linearly polarized light La' and Lb 'vertically incident from the front of the user into the polarization direction X.
And only the linearly polarized light La 'is transmitted.

According to such a configuration, the display a
Is polarized in the predetermined direction X by the polarizer c, and becomes a linearly polarized light La ′ shown in FIG. The linearly polarized light La 'is reflected by the half mirror e, and the traveling direction is bent at a right angle.

On the other hand, white light L emitted from the white light source b
b is a direction Y perpendicular to the polarization direction X by the polarizer d.
And becomes the linearly polarized light Lb 'shown in FIG. The linearly polarized light Lb 'is reflected by the mirror f, the traveling direction is bent at a right angle, and then passes through the half mirror e to be combined with the linearly polarized light La'.

When the linearly polarized light La 'and Lb' are combined, a combined light La'b 'shown in FIG. 4 is obtained. And
This combined light La′b ′ is polarized in the polarization direction X by the analyzing glasses g worn by the user. As a result, only the linearly polarized light La '(see FIG. 2), which is a component in the polarization direction X, passes through the analyzing glasses g, and the user can recognize the display information on the display a. . On the other hand, a third party who does not wear the analyzing glasses g directly sees the combined light La′b ′ obtained by combining the Y-direction components of the white light, and cannot recognize the display information on the display a. .

As described above, according to this embodiment, only the user wearing the analyzing glasses g can recognize the display information on the display a, so that highly confidential information can be obtained in a public place or the like. Even if displayed, confidentiality can be maintained. Therefore, let alone a display device such as a portable computer, for example, a station employee who is applied as a part of a display device of station equipment installed on a platform or the like of a station or as a display device and wears the above-mentioned analysis glasses g. It is also possible to make it possible for only the related persons to recognize the display information regarding the work.

In the case where linearly polarized light is used as in this embodiment, if the user wearing the analyzing glasses g tilts his / her face, the polarization direction at the time of the above-mentioned analysis changes, so that the display information is displayed. May not be identified. Therefore, not only linearly polarized light as in this embodiment but also circularly polarized light may be used to widen the angle range at the time of light analysis in which display information can be recognized.

[0017]

As described above, according to this invention, after the display means displays the information and emits the display light corresponding to the information, the polarizing means converts the display light into the first polarized light. direction of
Polarize only . Then, the combining means polarizes the unpolarized light corresponding to the white light in a second polarization direction perpendicular to the first polarization direction, and superimposes the light on the display light polarized by the polarization means to combine. Generate light. Further, an analyzing unit polarizes the combined light in the first polarization direction to extract the display light. This allows third parties other than the user to
Since the synthesized light is directly viewed, the display information cannot be recognized, so that even when displaying highly confidential information in a public place, a third party other than the user can view the display information. It is not possible to keep confidentiality.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing linearly polarized light La ′ in which display light La is polarized in a deflection direction X by a polarizer c.

FIG. 3 is a diagram showing linearly polarized light Lb ′ in which white light Lb is polarized in a deflection direction Y by a polarizer d.

FIG. 4 is a diagram showing combined light La′b ′ in which linearly polarized light La ′ and Lb ′ are combined.

[Explanation of symbols]

 a display b white light source c, d polarizer e half mirror f mirror g analysis glasses

Claims (1)

(57) [Scope of request for utility model registration] 1. A display means for displaying information and emitting display light according to the information; a polarizing means for polarizing display light from the display means only in a first polarization direction; a white light source; Combining means for polarizing unpolarized light from the light source in a second polarization direction perpendicular to the first polarization direction, and superimposing the polarization light on the display light polarized by the polarization means to generate combined light; A display device, comprising: an analyzer mounted on a user and configured to extract the display light by polarizing the combined light in the first polarization direction.