KR20000065735A - Head Mount Display Apparatus with Reduced Fatigue and Image Display Element Therefor - Google Patents

Abstract

PURPOSE: A head mount display for reducing fatigue and a picture display element for the same are provided to reduce the fatigue of user's eyes by applying a constant voltage to a peripheral space of a picture display element. CONSTITUTION: A head mount display for reducing fatigue and a picture display element for the same comprise a light source(30), a lighting optical system(40), a light separation element(20), a picture display element(10), and a patterned image system(50). The lighting optical system illuminates the light generated from the light source. The light separation element separates the light according to a predetermined rate. The picture display element displays the light received from the light separation element according to input picture data. The patterned image system displays the image to a user. In the head mount display, a portion except for a valid display area is covered with a color in order to reflect the light.

Description

Head Mount Display Apparatus with Reduced Fatigue and Image Display Element Therefor}

The present invention relates to a fatigue-reducing LCD image display device, and more particularly, to an apparatus for reducing fatigue of a user's eyes by maintaining a constant brightness in a shading state in an LCD image display device mainly used for HMD. .

LCD stands for Liquid Crystal Display, which was first discovered by F. Reinitzer in Austria in 1888 and applied to displays by RCA in 1968. Since 986, STN LCD and small TFT LCD have been put into practical use in LCDs and electronic clocks. As mass production of 10-inch TFT LCD has been realized in the 1990s, it has become a representative display of notebook PCs and has been spotlighted as one of the alternatives to CRT. LCD is widely used in electronic products such as electronic clocks, electronic calculators, LCD TVs, notebook PCs, etc. in speed displays and driving systems of automobiles and aircrafts, and its use is being expanded due to its small volume, low power consumption, and portableness. .

LCD is a device using a kind of optical switch that displays numbers or images by generating contrast by injecting liquid crystal, which is an intermediate between solid and liquid, between two thin glass plates and changing the arrangement of liquid crystal molecules by the voltage difference between electrodes on the upper and lower glass plates. All. The passive matrix method is classified into a passive matrix method and an active matrix method according to a driving method. Passive matrix methods include twisted nematic (TN) and super twisted nematic (STN), and thin film transistor (TFT) is an active matrix method. In particular, TFT LCDs are generally used as monitors of notebook PCs because of their fast response speed and thinness, and are expected to be used as home TVs due to the development of manufacturing technology and the expansion of screen sizes.

Head mounted display (HMD) is a device that a person attaches to the head and uses a new LCD image element and provides an optically enlarged image to the wearer's eyes so that they can visually see a large screen. For example, U.S. Patent No. 5,483,307 projects an image generated from an LCD special light modulator with a projection lens, magnifies it, and then reflects it with a beam splitter to reflect the image back to a curved reflector to the human eye. Present the device to provide.

As such, the LCD image display device used in the HMD and the like can generate a very small and clear image. For example, US Pat. No. 4,839,707 describes an improved LCMOS LCD. The LCD according to this document is configured to form a dielectric layer on a silicon wafer substrate and form an image by a silicon device disposed thereon.

Since the LCD image display device and the HMD device employing the same are formed on the user's head and the surrounding light is blocked, the user's image is directly responded to the user's eyes according to the contrast of the provided image. do. In the darkest and brightest conditions, the human eye repeats the expansion and contraction in the range of the pupil size of the eye from maximum 8mm to minimum 1mm. Accordingly, the pupil of the user's eye viewing the image wearing the HMD continuously repeats the process of minimizing and maximizing in the range of 1 to 8 mm according to the contrast of the provided image, thereby feeling extreme eye fatigue.

Due to such eye fatigue, not only can the HMD not be used for a long time, but there is a concern that the long-term use may cause deterioration of vision. For the elderly, especially children, sudden changes in contrast or flashing scenes may cause light seizures.

The present invention has been made to overcome the problems of the prior art, the object is to provide a head-mounted display device that can reduce the eyestrain of the user.

Another object of the present invention is to provide a video display device that can be used in the head-mounted display device to reduce the eye fatigue of the user.

1 is a view schematically showing the configuration of a head mounted display device;

2A is a view showing an illumination area of a conventional video display device;

2B illustrates an illumination area of at least 5% of an effective display area in accordance with the present invention;

3A is a view showing a conventional image display device with black surface treatment;

3B is a view showing an image display device colored in accordance with the present invention;

4A is a view showing a state in which the pupil is minimized,

4B is a view showing a state in which the pupil is maximized,

5A is a view showing an image display device configured to induce chromatic light emission in a free space according to the present invention;

5B is a cross-sectional view taken along the line A-A of FIG. 5A;

5C is an enlarged cross-sectional view of FIG. 5B.

♣ Explanation of symbols for the main parts of the drawing ♣

10: video display element 11: effective display area

12: lighting area 13: enlarged lighting area

14: black surface treatment area 15: colored surface treatment area

20: optical separation element 30: light source

40: illumination optical system 50: imaging optical system

60: eyes

According to the present invention, a light source, an illumination optical system for illuminating light generated from the light source, an optical separation element for separating light incident from the illumination optical system at a predetermined ratio, and light incident from the optical separation element are inputted. A head mounted display device comprising an image display element for reflecting an image according to image data to display an image, and an imaging optical system for providing an image to a user's eyes through the optical separation element. There is provided a head mounted display device capable of reducing fatigue, wherein the light is illuminated such that a range of illumination light illuminating the image display element is 5% or more of the effective display screen based on the area.

According to another feature of the present invention, there is provided an image display element for a head mounted display device in which chromatic color processing 15 is applied to a portion other than the effective display area of the image display element 10.

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

1 is a view schematically showing the configuration of a head mounted image display device according to the present invention. Light generated from the light source 30 is incident on the light separation element 20 through the light separation element 20 through the illumination optical system 40, and the light separation element 20 is light incident on the illumination optical system 40. Is separated into a predetermined ratio and sent to the image display element 10. The image display element 10 displays an image according to the input image signal, and the image displayed on the image display element 10 is incident to the imaging optical system 50 through the optical separation element 20. The user's eye 60 sees the image shown through the imaging optical system 50.

The image detected through the eye 60 is shown as shown in FIG. 2A, in which the illumination light 12 displays only the effective display area 11. In the conventional video display device, as shown in FIG. 3A, the surface of the image is black 14, so that the user's eye 60 sees only the effective display area 11 of the screen. Therefore, as described above, the user is dependent on the brightness of the image, so that the pupil of the eye is minimized in the brightest state (FIG. 4A) and maximized in the darkest state (FIG. 4B). The muscles of the pupil acts easily, making eyes tired.

2 shows a configuration of a display element 10 according to the present invention. The illumination optical system 40 is designed to illuminate even a package portion of the display element 10, and the display element 10 is effective. By treating the portions other than the display area 11 with the chromatic color 15, the user can view the portions other than the effective screen of the display element 10.

In the present specification, the term "chromatic color" refers to a color exhibiting a constant brightness, including white, gray, and various natural colors, despite the academic definition, and means something other than black. The image display element 10 according to the present invention is colored to a portion other than the effective display region 11 to provide a constant brightness. However, it is more preferable to use green as the color that gives the most stability and less fatigue to the human eye.

Therefore, even when there is no information from the image display element 10, the part illuminated beyond the effective display area 11 and the chromaticized part can be visually seen, so that the pupil is enlarged by the constant brightness of the part. It is not possible to maintain a constant size.

As such, the pupil maintained at a constant size is adapted to the average value of the brightness according to the video signal and the brightness of the illuminated or colored portion exceeding the effective display area 11 even if the brightness changes according to the video signal. The size of the pupil changes. Also, the actual size change of the pupil is not because it is enlarged from any intermediate part (middle point) but recovered from the mid point, then reduced from the mid point and then back to the mid point. In the case of applying the conventional display element, the maximum and minimum size changes are much smaller than about 7 mm, for example, only about 3 to 5 mm. It is reduced.

5 illustrates an embodiment in which a predetermined fixed voltage is applied to a free space (Peripheri or Apron) of an image display device according to the present invention.

FIG. 5A shows a display surface of a conventional reflective liquid crystal display device, wherein the display area 11 includes an actual screen display unit 16 and a free space 17 around it. FIG. 5B shows the cross section of FIG. 5A and FIG. 5C schematically shows an enlarged cross section.

The video display element 10 includes a display area 11, a screen display unit 16, a free space 17, a liquid crystal 18, and a cover glass 19. The screen display unit 16 is a portion in which actual image data is applied to drive the liquid crystal 18 according to the contents of the data, and the free space 17 maintains a predetermined fixed voltage. The voltage applied at this time is applied so as to remain black in the conventional device, but according to the present invention, a predetermined fixed voltage is applied so that the free space 17 exhibits a color other than white or other black. Therefore, since a constant brightness is formed by the color development of the free space, it is possible to avoid a sudden change in brightness depending only on the image to reduce eye fatigue of the user.

As is apparent from the above description, the head mounted display device according to the present invention makes the eyes of the user magnified or reduced easily by relying only on the brightness of the image of the display device in a dark environment where external light is blocked. The fatigue can be prevented. Therefore, the head mounted display device according to the present invention has an advantage of reducing fatigue while using a user for a long time.

Although the present invention has been described in detail with reference to the preferred embodiments, various modifications, changes and modifications can be made without departing from the spirit and scope of the present invention. It should be understood that it falls within the scope of the present invention.

Claims (4)

A light source 30, an illumination optical system 40 for illuminating light generated from the light source 30, an optical separation element 20 for separating light incident from the illumination optical system 40 at a predetermined ratio, and An image display device 10 for displaying an image by reflecting light incident from the optical separation device according to the input image data, and an image providing the image to the eyes of the user through the optical separation device 20. In the head mounted display device including the optical system 50, a range of illumination light that the illumination optical system 40 illuminates the image display element 10 is 5% or more of the effective display screen 11 based on the area. A head mounted display device capable of reducing fatigue, wherein the light is illuminated. 2. An apparatus according to claim 1, wherein the image display element (10) is colored in portions other than the effective display area (11) so that the image light can reflect the illumination light. An apparatus according to claim 1, wherein a chromatic color is generated by applying a predetermined voltage to an electrode of the free space (17) of the image display element (10). An image display element for a head mounted display device, wherein chromatic color processing (15) is performed on portions other than the effective display area of the image display element (10).