JP2010169743A - Head-mounted image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve image quality by preventing a contrast decrease and imprint, which are caused by outdoor light, while extending a peripheral view and also decreasing feeling of devotion. <P>SOLUTION: A head-mounted image display apparatus 1 includes: an optical device having a display element that is disposed in front of the eyes of a wearer, in the position where its viewing range is partially blocked and that displays an image, and also having an eyepiece optical system that guides an image displayed on the display element, to the eyes of the wearer; a mounting frame 3 supporting the optical device and used for mounting it on the head A of the wearer; and a light attenuating means 4 that is disposed on the optical axis where outdoor light entering the positions of the pupils of the wearer after its specular reflection on the emission surface 2a of the optical device enters the emission surface 2a of at least the optical device, and that reduces the intensity of the outdoor light. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a head-mounted image display device.

  Conventionally, as a head-mounted image display device, a head-mounted image display provided with a display element attached to an eyeglass-type frame and disposed at a position where the display element deviates from the field of view when the wearer looks straight ahead. An apparatus is known (for example, refer to Patent Document 1).

International Publication No. 2004/017120 Pamphlet

  However, in the conventional head-mounted image display device, there is a problem that an immersive feeling that only the image is immersed increases when the distance (eye relief) between the eye and the display element is short. To solve this problem, increasing the eye relief can increase the peripheral vision and reduce the immersive feeling.However, the screen must be enlarged, and the image can be reduced by contrast reduction or reflection due to external light. There is a problem that the quality deteriorates.

  The present invention has been made in view of the above-described circumstances, and it is possible to improve the image quality by increasing the peripheral visual field and reducing the immersive feeling while preventing a decrease in contrast and reflection due to external light. An object of the present invention is to provide a head-mounted image display device that can be used.

In order to achieve the above object, the present invention provides the following means.
The present invention is arranged in front of the wearer's eyes at a position that partially blocks the visual field range, and displays a display element, and an eyepiece optical system that guides the image displayed on the display element to the wearer's eye An optical device comprising: a mounting frame that supports the optical device and is mounted on the head of the wearer; and at least the external light that is regularly reflected on the exit surface of the optical device and is incident on the pupil position of the wearer Provided is a head-mounted image display device that is disposed on an optical axis of incidence on the exit surface of an optical device and includes a dimming unit that reduces the intensity of external light.

  According to the present invention, when the wearer wears the optical device on the head with the wearing frame, the optical device is arranged in front of the wearer's eyes, so that the image displayed on the display element is enlarged via the eyepiece optical system. You can see. Since the optical device is disposed at a position that partially obstructs the wearer's visual field range, not only the image by the optical device but also the peripheral visual field can be confirmed, and the feeling of immersion can be reduced.

  In this case, when a large eye relief is secured to secure a sufficient peripheral field of view, external light is incident on the exit surface of the optical device. The external light incident on the position is blocked by the dimming means disposed on the optical axis incident on the exit surface, and the intensity is reduced. As a result, it is possible to prevent a decrease in the contrast of the image provided by the optical device and a decrease in the image quality due to the reflection.

In the above invention, the dimming means may be a half mirror.
In the above invention, the dimming means may be an ND (Neutral Density) filter.
By doing so, it is possible to easily and effectively reduce the intensity of external light that is incident on the exit surface of the optical device and is regularly reflected to the pupil position, thereby preventing a reduction in image quality.

In the above invention, a sensor for detecting the intensity of external light may be provided, and the dimming unit may change the degree of reducing the intensity of external light according to the intensity of external light detected by the sensor. Good.
In this way, when the external light intensity is high, the external light is sufficiently diminished to improve the image quality, and when the external light intensity is low, the degree of dimming is reduced and the field of view is unnecessary. It can prevent being restricted to.
Moreover, in the said invention, the said light reduction means may be a liquid crystal filter. Thereby, the degree of dimming can be easily adjusted.

In the above invention, a plurality of the sensors may be provided, and the dimming unit may change the degree of reducing the intensity of external light for each region close to the sensor.
By doing so, a bright field of view can be secured in a range where light shielding is not necessary.

In the above invention, the dimming means may be disposed behind a plane that passes through the pupil position of the eyepiece optical system and is orthogonal to the optical axis of the eyepiece optical system.
By doing in this way, a light reduction means can be arrange | positioned out of a visual field range, and it can prevent that a visual field range is restrict | limited by a light reduction means.

Moreover, in the said invention, the said light reduction means may be extended along the wearer's side head in the state with which the wearer's head was mounted | worn.
By doing in this way, it can arrange | position so that a dimming means may not jump out of a head in the state with which it mounted | weared with the wearer's head.

  According to the present invention, it is possible to improve the video quality by increasing the peripheral visual field and reducing the immersive feeling while preventing the decrease in contrast and reflection due to external light.

It is a top view which shows the state with which the head which shows the head mounted image display apparatus which concerns on one Embodiment of this invention was mounted | worn. It is a schematic diagram which shows the internal structure of the optical apparatus with which the head mounted image display apparatus of FIG. 1 is equipped. FIG. 2 is a side view showing a state where the head-mounted image display device of FIG. 1 is mounted on the head. FIG. 6 is a side view showing a first modification of the head-mounted image display device of FIG. 1 and having a liquid crystal shutter as a light reducing means. FIG. 5 is a side view showing a case where the intensity of external light is low in the head-mounted image display device of FIG. 4. FIG. 9 is a plan view showing a second modification of the head-mounted image display device of FIG. 1 and having a left and right liquid crystal shutter as dimming means. FIG. 7 is a plan view showing a case where the intensity of external light from the right side is low in the head-mounted image display device of FIG. 6. It is a side view which shows the 3rd modification of the head mounted type | mold video display apparatus of FIG. It is a top view explaining arrangement | positioning of the light reduction means of the head-mounted image display apparatus of FIG.

A head-mounted image display device 1 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the head-mounted image display device 1 according to the present embodiment includes an optical device 2 that displays an image, and a mounting frame 3 that mounts the optical device 2 on the head A of the wearer. , And a dimming means 4 fixed to the mounting frame 3.

As shown in FIG. 2, the optical device 2 includes a pair of LCDs (liquid crystal display devices) 5 with backlights for displaying images, and a pair for guiding the images displayed on the LCDs 5 to the eyes of the wearer. Prism (eyepiece optical system) 6.
The mounting frame 3 is formed in an annular shape surrounding the head A of the wearer, and has a U-shaped frame main body 7, a belt 8 that is slidable with respect to the frame main body 7 and can be adjusted in length, and the belt And a buckle 9 that removably connects the end portions of the eight.

  The optical device 2 is fixed to the tip of a shaft 7a provided at the center of the frame body 7, and when the wearer wears the wearing frame 3 on the head A, the optical device 2 partially covers the visual field range in front of both eyes of the wearer. A sufficient eye relief is formed and disposed so as to be disposed at a position where it is obstructed. In the figure, reference numeral 10 denotes a pad portion made of an elastic material such as urethane rubber that is elastically deformed by being pressed against the surface of the head A and fits the mounting frame 3 to the shape of the head A.

As shown in FIG. 3, the dimming means 4 is a half mirror (hereinafter referred to as a half mirror) disposed at a position covering almost the entire area of the wearer's visual field including the gap between the frame body 7 of the mounting frame 3 and the optical device 2. , Also referred to as half mirror 4). As a result, the wearer's visual field is occupied by the emission surface 2 a of the optical device 2 and the peripheral visual field covered with the peripheral half mirror 4.
The half mirror 4 has a transmittance of 50%, for example, and blocks about half of external light incident from the outside.

The operation of the head-mounted image display device 1 according to this embodiment configured as described above will be described below.
In order to use the head-mounted image display device 1 according to the present embodiment, the mounting frame 3 formed in an annular shape by adjusting the length of the belt 8 to the frame body 7 and fixing the buckle 9 is used. It arrange | positions so that the head A may be enclosed, and it mounts | wears with the head A by pressing the pad part 10 against the forehead B and the back head C, and pinching it.

When the image is displayed by operating the LCD 5, the image displayed on the LCD 5 is emitted in the direction of the wearer's eye via the eyepiece optical system 6. 2 images can be seen.
Further, since the optical device 2 is arranged with a sufficient eye relief, the wearer can obtain a peripheral visual field around the image by the optical device 2. Thereby, it is possible to prevent the occurrence of an immersive feeling that only immerses only the image displayed by the optical device 2.

  Furthermore, according to the head-mounted image display device 1 according to the present embodiment, since the peripheral visual field is covered with the half mirror 4, almost half of the external light incident from the outside is shielded. As a result, it is possible to prevent the occurrence of inconvenience that strong external light is incident on the LCD 5 via the eyepiece optical system 6 and the contrast of the image is lowered. Further, since the external light that is regularly reflected at the exit slope 2a of the eyepiece optical system 6 and enters the pupil position of the wearer can be reduced, the image quality is deteriorated due to the reflection of the external light on the wearer's eye. Can be prevented.

  In the present embodiment, a half mirror is used as the dimming means 4, but instead, an ND filter or a liquid crystal shutter may be used. The liquid crystal shutter can adjust the transmittance according to the state of the liquid crystal. The liquid crystal shutter 11 has a transmittance according to the intensity of the external light L detected by the wearer's operation or as detected by the illuminance sensor 12 disposed on the mounting frame 3 as shown in FIGS. Can be changed.

  In the example shown in FIG. 4, since the intensity of the external light L is high, the transmittance of the liquid crystal shutter 11 is reduced to increase the degree of light shielding. On the other hand, in the example shown in FIG. 5, since the intensity of the external light L is low, the transmittance of the liquid crystal shutter 11 is increased to reduce the degree of light shielding. As a result, when the intensity of the external light L is high, the intensity of the external light L incident on the exit surface 2a of the optical device 2 can be reduced, thereby preventing a reduction in video quality. On the other hand, when the intensity of the external light L is low, it is possible to obtain a bright peripheral visual field by increasing the transmittance (in FIGS. 4 to 7, a high density of oblique lines indicates a low transmittance, The low one is displayed as a high transmittance state.)

  Further, as shown in FIGS. 6 and 7, a plurality of illuminance sensors 12 are provided on the mounting frame 3 (in the example shown in FIGS. 6 and 7, at two left and right positions), and the liquid crystal shutter 11 corresponding to the left and right eyes is provided. The transmittance may be changed separately. The example shown in FIG. 6 is a case where the intensity of the external light L incident from both the left and right sides is approximately the same, and based on the detection result of the illuminance sensor 12, both liquid crystal shutters 11 have substantially the same low transmittance. is doing.

  In contrast, in the example shown in FIG. 7, the intensity of the external light L incident on the wearer from the right side is lower than the intensity of the external light incident from the left side, and based on the detection result of the left and right illuminance sensors 12, The transmittance of the right liquid crystal shutter 11 is larger than the transmittance of the left liquid crystal shutter 11. As a result, the left liquid crystal shutter 11 prevents the image contrast of the left optical device 2 from being lowered, and the right liquid crystal shutter 11 can obtain a bright peripheral field on the right side.

  In the example shown in FIGS. 6 and 7, the liquid crystal shutter 11 for adjusting the transmittance is divided into the left and right two parts and adjusted separately. Instead, the liquid crystal shutter 11 is divided into three or more in the left and right direction. Alternatively, it may be divided in the vertical direction. Further, the transmittance may be changed smoothly without being divided clearly.

  In the present embodiment, the entire visual field except the screen of the optical device 2 is covered by the light shielding means 4 and 11. Instead, as shown in FIG. At a position where the incident path of the external light L that is regularly reflected and incident on the pupil position D is obstructed, passes through the wearer's pupil position D, and only behind the plane F perpendicular to the optical axis E of the optical device 2. The light shielding means 4 may be arranged. In this way, the light shielding means 4 can be arranged outside the wearer's visual field range, and a wide peripheral bright visual field can be obtained at the same time, and deterioration of image quality due to reflection of external light is prevented. can do.

  In this case, there are various ways of arranging the light blocking means 4 on the incident optical axis of the external light L, but as shown in FIG. 9, in the direction along the side G of the wearer. By arranging, the light shielding means 4 can be arranged in a compact manner without largely projecting outward from the head A.

  In the present embodiment, the dimming means 4 and 11 are fixed to the mounting frame 3, but instead of this, they may be detachably attached. Moreover, although it decided to fix to the lower part of the frame main body 7, you may decide to arrange | position a frame main body in the position lower than a wearer's eyes, and to attach a light reduction means to the upper part. Moreover, you may employ | adopt the light reduction means of the form closely_contact | adhered to a wearer's face like goggles.

A head D pupil position F plane G side head L external light 1 head-mounted image display device 2 optical device 2a exit surface 3 mounting frame 4 half mirror (dimming means)
5 LCD (display element)
6 Prism (eyepiece optical system)
11 Liquid crystal filter (dimming means)
12 Illuminance sensor (sensor)

Claims (8)

An optical element that is disposed in front of the wearer's eyes and is disposed at a position that partially blocks the visual field range, and that displays an image and an eyepiece optical system that guides the image displayed on the display element to the wearer's eye Equipment,
A mounting frame that supports the optical device and is mounted on the head of the wearer;
Attenuating means for reducing the intensity of the external light, which is arranged on at least the incident optical axis of the external light that is regularly reflected on the exit surface of the optical device and is incident on the wearer's pupil position. A head-mounted image display device comprising:   The head-mounted image display device according to claim 1, wherein the dimming means is a half mirror.   The head-mounted image display device according to claim 1, wherein the dimming means is an ND filter. It has a sensor that detects the intensity of outside light,
The head-mounted image display device according to claim 1, wherein the dimming unit changes the degree of reducing the intensity of external light according to the intensity of external light detected by the sensor.   The head-mounted image display device according to claim 4, wherein the dimming means is a liquid crystal filter. A plurality of the sensors are provided,
The head-mounted image display device according to claim 4 or 5, wherein the dimming means changes a degree of reducing the intensity of external light for each region close to the sensor.   The head-mounted image display device according to claim 1, wherein the dimming unit is disposed behind a plane passing through the pupil position of the eyepiece optical system and orthogonal to the optical axis of the eyepiece optical system.   The head-mounted image display device according to claim 7, wherein the dimming means extends along the side of the wearer in a state of being mounted on the head of the wearer.

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