JP5104823B2 - Display device - Google Patents

Description

  The present invention relates to an information device that can be used in an environment other than a desktop, such as a wearable computer that is worn on the body via a waist belt or a jewelry, or a communication device such as a mobile phone that can be carried in a knapsack or a pocket. The present invention relates to a display device suitable for a monitor.

As display devices for information devices that are worn on the body, eyeglass-type forms are becoming mainstream. FIG. 5 is an external view showing a conventional glasses-type display (display device) mounted on the viewer's head, and FIG. 6 is a schematic configuration of a conventional glasses-type display mounted on the viewer's head. FIG.
The eyeglass-type display 401 has an appearance similar to that of eyeglasses, and guides it to the observer's eye E while internally reflecting the image display light L from the unit portion U that emits the image display light L and the unit portion U. The light guide 404 which is a board | substrate, and the flame | frame part F to which the unit part U and the light guide 404 are attached are provided (for example, refer patent document 1).
Note that the glasses-type display 401 is for the right eye and defines an XYZ coordinate system having an origin at the center of the right eye E in a state of looking far away. The Z direction is in front of the observer, the Y direction is above the observer, and the X direction (setting direction) is to the left of the observer.

The unit unit U has an emission mechanism having a transmissive liquid crystal display (display element) 2 that forms an image to be a display region (X ₁ × Y ₁ ) on a surface perpendicular to the emission direction and emits image display light L. S and an optical system 3 that forms a virtual image of an observation object.
The emission mechanism S includes a light source (not shown) and a transmissive liquid crystal display 2. The transmissive liquid crystal display 2 forms an image to be a display area (X ₁ × Y ₁ ) on a surface perpendicular to the emission direction based on an image signal from a control unit (not shown), and displays the image. Light L is emitted.
The optical system 3 transmits the image display light L in the display region (X ₁ × Y ₁ ) to form a virtual image to be observed.

The light guide 404 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end and is formed at the other end with a planar total reflection surface 441 disposed in front of the emission mechanism S (Z direction). It has an emission surface 442 arranged in front of the observer's eye E (Z direction), and a side group 446 formed between the total reflection surface 441 and the emission surface 442 by an interface with air.
The side group 446 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 446a, a second surface 446b facing the first surface 446a in the Z direction, a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction.

The emission surface 442 includes a planar first emission surface 442a, a planar second emission surface 442b, and a planar third emission surface 442c. And it arrange | positions so that it may become the 1st output surface 442a, the 2nd output surface 442b, and the 3rd output surface 442c in order in a X direction (setting direction). Furthermore, the angle of the first exit surface 442a with respect to the X direction, the angle of the second exit surface 442b with respect to the X direction, and the angle of the third exit surface 442c with respect to the X direction are the same θ ₁ when viewed from the Y direction. Is arranged.
The first emission surface 442a, the second emission surface 442b, and the third emission surface 442c reflect 19% of the incident light beam of the image display light L and transmit 81% of the light beam of the image display light L. It is possible.

In such a light guide 404, first, the total reflection surface 441 reflects the image display light L in the display area (X ₁ × Y ₁ ) from the optical system 3 in a substantially X direction (setting direction). The first surface 446a and the second surface 446b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first emission surface 442a while alternately reflecting the image display light L a plurality of times. Therefore, the first emission surface 442a reflects 19% of the incident light flux of the image display light L and transmits 81% of the light flux of the image display light L. That is, the light flux of the image display light La that is 19.0% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 442a reaches the second emission surface 442b. Therefore, the second exit surface 442b reflects 19% of the incident light beam of the image display light L and transmits 81% of the light beam of the image display light L. That is, the light flux of the image display light Lb that is 15.4% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 442b reaches the third emission surface 442c. Therefore, the third exit surface 442c reflects 19% of the incident light flux of the image display light L and transmits 81% of the light flux of the image display light L. That is, the light flux of the image display light Lc that is 12.5% of the light flux of the image display light L is guided toward the observer. As described above, the light emission surfaces 442a, 442b, and 442c reflect the image display light L, so that the image display light L in the display region (X ₁ × Y ₁ ) is emitted outside the light guide 404. As a result, the image display light L emitted from the emission mechanism S is guided to the observer's eye E through the light guide 404.

However, since the image display light L is sequentially guided to the first emission surface 442a, the second emission surface 442b, and the third emission surface 442c, the luminous flux (19.0%) of the image display light La from the first emission surface 442a. And the problem that the luminous flux (15.4%) of the image display light Lb from the second emission surface 442b and the luminous flux (12.5%) of the image display light Lc from the third emission surface 442c become smaller in order. There was a point. That is, the virtual image observed by the observer has uneven brightness.
Therefore, the first emission surface 442a reflects 19% of the incident light beam of the image display light L and allows 81% of the light flux of the image display light L to pass therethrough, and the second emission surface 442b In addition to reflecting 23% of the luminous flux of the image display light L, it is possible to transmit 77% of the luminous flux of the image display light L, and the third emission surface 442c is 31% of the luminous flux of the incident image display light L. It is conceivable to develop a glasses-type display that can reflect 69% and transmit 69% of the luminous flux of the image display light L.

In such a light guide 404, first, the total reflection surface 441 reflects the image display light L in the display area (X ₁ × Y ₁ ) from the optical system 3 in a substantially X direction (setting direction). The first surface 446a and the second surface 446b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first emission surface 442a while alternately reflecting the image display light L a plurality of times. Therefore, the first emission surface 442a reflects 19% of the incident light flux of the image display light L and transmits 81% of the light flux of the image display light L. That is, the light flux of the image display light La that is 19% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 442a reaches the second emission surface 442b. Therefore, the second exit surface 442b reflects 23% of the incident light flux of the image display light L and transmits 77% of the light flux of the image display light L. That is, the light flux of the image display light Lb that is 19% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 442b reaches the third emission surface 442c. Therefore, the third emission surface 442c reflects 31% of the incident light flux of the image display light L. That is, the light flux of the image display light Lc that is 19% of the light flux of the image display light L is guided toward the observer. As described above, the light emission surfaces 442a, 442b, and 442c reflect the image display light L, so that the image display light L in the display region (X ₁ × Y ₁ ) is emitted outside the light guide 404. As a result, the image display light L emitted from the emission mechanism S is guided to the observer's eye E through the light guide 404.

However, since the first output surface 442a, the second output surface 442b, and the third output surface 442c have different transmittances of the incident image display light L, the external environment observed by the observer through the first output surface 442a. There is a problem that the brightness, the brightness of the external environment observed by the observer via the second exit surface 442b, and the brightness of the external environment observed by the observer via the third exit surface 442c are different. That is, there was uneven brightness in the external environment observed by the observer.
Further, the image display light L of a light beam that is 43% of the light beam of the image display light L passes through all the emission surfaces 442 of the first emission surface 442a, the second emission surface 442b, and the third emission surface 442c. There is also a problem that the brightness of the virtual image observed by the observer is lowered.

Therefore, a spectacle-type display is developed that reflects the image display light L that has passed through all of the exit surfaces 442 of the first exit surface 442a, the second exit surface 442b, and the third exit surface 442c again toward the exit surface 442. (For example, refer to Patent Document 2). Exit surface in such eyeglass display includes a first reflecting surface of the planar shape angle to the X direction becomes theta _3, a second reflecting surface of the planar shape angle is theta ₄ with respect to the X direction are arranged alternately The final reflection surface is formed at the end in the X direction. As a result, the image display light traveling in the substantially X direction is guided toward the observer by the first reflecting surface, and the image display light traveling in the X direction is further reflected by the final reflecting surface in the approximately −X direction. The image display light traveling in the −X direction is guided toward the observer by the second reflecting surface.

Special table 2003-536102 gazette International Publication WO2005 / 088384

However, on the exit surface of the eyeglass-type display as described above, the brightness of the virtual image observed by the observer can be increased. However, the image display light traveling in the substantially X direction with one light guide is also approximately − Since the image display light traveling in the X direction is also reflected, there are problems that stray light is mixed in the virtual image observed by the observer, or a region where there is no light beam observed by the observer is generated.
Therefore, an object of the present invention is to provide a display device capable of suppressing occurrence of luminance unevenness between a virtual image observed by an observer and the outside world. It is another object of the present invention to provide a display device that can increase the luminance of a virtual image observed by an observer.

  In order to solve the above problems, the display device of the present invention forms an image serving as a display region, and includes an emission mechanism having a display element that emits image display light, and a virtual image of an observation target. An optical system that reflects or transmits image display light; a first surface; a second surface that faces the first surface; and an exit surface that is disposed in front of an observer's eye; And / or a first light guide that guides the image display light from the optical system to the exit surface while reflecting the image display light from the optical system to the setting direction on the second surface, and guides the image display light from the exit surface to the eyes of the observer. The first light guide includes a guide surface that guides image display light to the second light guide on the back side of the emission surface of the first light guide in the setting direction, The second light guide faces the first surface and the first surface. Opposite setting that has two surfaces and an exit surface disposed in front of the eyes of the observer, and the image display light from the first light guide is opposite to the setting direction on the first surface and / or the second surface The image display light is guided to the observer's eye from the exit surface while being reflected in the direction, and the image display light from the exit surface of the first light guide and the exit surface of the second light guide The image display light overlaps with the viewer's eyes.

  According to the display device of the present invention, the first light guide and the second light guide are provided. The first light guide guides the image display light to the exit surface while reflecting the image display light in the setting direction. Furthermore, the image display light that has passed through the exit surface of the first light guide is guided to the second light guide. The second light guide guides the image display light to the exit surface while reflecting the image display light in the opposite setting direction. Accordingly, the image display light from the exit surface of the first light guide and the image display light from the exit surface of the second light guide are guided to the observer's eyes so as to overlap. At this time, in the first light guide, the light is emitted so that the luminance of the image display light decreases in the order of the setting direction, but in the second light guide, the luminance of the image display light increases in the order of the setting direction. Will be emitted.

  As described above, according to the display device of the present invention, it is possible to suppress the occurrence of luminance unevenness between the virtual image observed by the observer and the outside world.

(Means and effects for solving other problems)
In order to solve the above problems, the display device of the present invention forms an image serving as a display region, and includes an emission mechanism having a display element that emits image display light, and a virtual image of an observation target. An optical system that reflects or transmits image display light; a first surface; a second surface that faces the first surface; and an exit surface that is disposed in front of an observer's eye; And / or a first light guide that guides the image display light from the optical system to the exit surface while reflecting the image display light from the optical system to the setting direction on the second surface, and guides the image display light from the exit surface to the eyes of the observer. The first light guide includes a guide surface that guides image display light to the second light guide on the back side of the emission surface of the first light guide in the setting direction, The second light guide faces the first surface and the first surface. The first surface and / or the second surface guides the image display light from the first light guide to the guiding surface while reflecting it in the opposite setting direction opposite to the setting direction. The image display light is guided from the guide surface to the front side of the exit surface of the first light guide in the setting direction.

According to the display device of the present invention, the first light guide and the second light guide are provided. The first light guide guides the image display light to the exit surface while reflecting the image display light in the setting direction. Furthermore, the image display light that has passed through the exit surface of the first light guide is guided to the second light guide. The second light guide is guided to the guide surface while being reflected in the opposite setting direction. As a result, the image display light that has passed through the exit surface of the first light guide returns to the first light guide via the guide surface of the second light guide.
As described above, according to the display device of the present invention, the luminance of the virtual image observed by the observer can be increased.

In the above invention, the second light guide guides the image display light to the back side of the emission surface of the second light guide in the opposite setting direction and to the front side of the emission surface of the first light guide in the setting direction. You may make it have a guidance surface.
In the above invention, the emission surface of the first light guide has N emission surfaces so that the emission surfaces are in order in the setting direction, and the emission surface of the second light guide is in the opposite setting direction. From the nth emission surface in the first light guide, the image display light from the nth emission surface and the (N + 1−n) th emission surface in the second lightguide. The image display light may be superimposed on the eyes of the observer.
In the above invention, the N exit surfaces of the first light guide and the N exit surfaces of the second light guide may have the same reflectance.

Furthermore, in the above invention, the exit surfaces of the first light guide and the second light guide may be diffractive surfaces.
In the above invention, the display element emits P-polarized light or S-polarized image display light, and the first light guide is located on the front side of the light emitting surface of the first light guide in the setting direction. You may make it have the polarization conversion surface in which the image display light from two light guides are guide | induced, and the polarization beam splitter surface in which the image display light from the said display element is guide | induced in this order.

1 is an optical path diagram illustrating a schematic configuration of a glasses-type display that is an embodiment of the present invention. 1 is an optical path diagram illustrating a schematic configuration of a glasses-type display that is an embodiment of the present invention. 1 is an optical path diagram illustrating a schematic configuration of a glasses-type display that is an embodiment of the present invention. 1 is an optical path diagram illustrating a schematic configuration of a glasses-type display that is an embodiment of the present invention. It is an external view which shows the conventional spectacles type display with which an observer's head is mounted | worn. It is an optical path diagram which shows schematic structure of the conventional spectacles type display with which an observer's head is mounted | worn.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

<Embodiment 1>
FIG. 1 is an optical path diagram showing a schematic configuration of a glasses-type display (display device) according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the thing similar to the spectacles type display 401 mentioned above.
The eyeglass-type display 1 includes a unit unit U that emits image display light L, a first light guide 4 that is a substrate that guides the image display light L from the unit unit U to the eye E of the observer while reflecting the inside, and Two light guides 5, a unit portion U, a first light guide 4, and a frame portion F to which the second light guide 5 is attached.
The second light guide 5 is disposed in front of the first light guide 4 (Z direction).

The first light guide 4 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end and is disposed in front (Z direction) of the emission mechanism S, and has a planar reflection surface 41 at the other end. A planar total reflection surface (guidance surface) 43 to be formed, and an emission surface 42 formed between the total reflection surface 41 and the total reflection surface 43 and disposed in front of the observer's eye E (Z direction); And a side group 46 formed between the total reflection surface 41 and the total reflection surface 43 by an interface with air.
The side group 46 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 46a, a second surface 46b facing the first surface 46a in the Z direction, a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction.

The emission surface 42 includes a planar first emission surface 42a, a planar second emission surface 42b, and a planar third emission surface 42c. And it arrange | positions so that it may become the 1st output surface 42a, the 2nd output surface 42b, and the 3rd output surface 42c in order in a X direction (setting direction). Furthermore, the angle of the first exit surface 42a with respect to the X direction, the angle of the second exit surface 42b with respect to the X direction, and the angle of the third exit surface 42c with respect to the X direction are the same θ ₁ when viewed from the Y direction. Is arranged.
The first emission surface 42a, the second emission surface 42b, and the third emission surface 42c reflect 10% of the incident light flux of the image display light L and transmit 90% of the light flux of the image display light L. It is possible.

  The total reflection surface 43 is arranged last in the X direction (setting direction). The total reflection surface 43 can reflect the incident image display light L toward the second light guide 5. As a result, the image display light L that has transmitted through all the emission surfaces of the first emission surface 42a, the second emission surface 42b, and the third emission surface 42c is guided toward the second light guide 5.

The second light guide 5 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end and is disposed in front of the total reflection surface 43 (Z direction), and a planar total reflection surface 53. It has an emission surface 52 disposed in front of the eye E (Z direction) and a side group 56 formed by an interface with air.
The side group 56 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 56a, a second surface 56b facing the first surface 56a in the Z direction, a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction. And it arrange | positions so that the 2nd surface 56b of the 2nd light guide 5 and the 2nd surface 46b of the 1st light guide 4 may oppose.

The exit surface 52 includes a planar first exit surface 52c, a planar second exit surface 52b, and a planar third exit surface 52a. The first emission surface 52c, the second emission surface 52b, and the third emission surface 52a are sequentially arranged in the −X direction (opposite setting direction). Furthermore, the angle of the first exit surface 52c with respect to the −X direction (opposite setting direction), the angle of the second exit surface 52b with respect to the −X direction, and the angle of the third exit surface 52a with respect to the −X direction are from the Y direction. They are arranged so as to have the same θ ₂ when viewed.
The first emission surface 52c, the second emission surface 52b, and the third emission surface 52a reflect 10% of the incident light flux of the image display light L and transmit 90% of the light flux of the image display light L. It is possible.

In such a glasses-type display 1, the total reflection surface 41 of the first light guide 4 reflects the image display light L in the display region (X ₁ × Y ₁ ) from the optical system 3 in the substantially X direction. The first surface 46a and the second surface 46b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first emission surface 42a while alternately reflecting the image display light L a plurality of times. Therefore, the first emission surface 42a reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light La that is 10% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 42a reaches the second emission surface 42b. Therefore, the second exit surface 42b reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Lb that is 9% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 42b reaches the third emission surface 42c. Therefore, the third exit surface 42c reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Lc that is 8.1% of the light flux of the image display light L is guided toward the observer.
Thereafter, the image display light L transmitted through the third emission surface 42 b reaches the total reflection surface 43. Therefore, the total reflection surface 43 reflects the incident image display light L toward the total reflection surface 53 of the second light guide 5.

The total reflection surface 53 of the second light guide 5 reflects the image display light L in the display area (X ₁ × Y ₁ ) from the first light guide 4 in a substantially −X direction. The first surface 56a and the second surface 56b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first emission surface 52c while alternately reflecting the image display light L a plurality of times. Therefore, the first emission surface 52c reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Ld that is 6.6% of the light flux of the image display light L is guided toward the observer through the third emission surface 42 c of the first light guide 4. At this time, since the image display light Ld and the image display light Lc overlap, the light beam of the image display light that is 14.7% of the light beam of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 52c reaches the second emission surface 52b. Therefore, the second emission surface 52b reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light beam of the image display light Le that is 5.9% of the light beam of the image display light L is guided toward the observer through the second emission surface 42 b of the first light guide 4. At this time, since the image display light Lb and the image display light Le overlap, the light flux of the image display light that is 14.9% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 52b reaches the third emission surface 52a. Therefore, the third exit surface 52a reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Lf, which is 5.3% of the light flux of the image display light L, is guided toward the observer through the first emission surface 42 a of the first light guide 4. At this time, the image display light La and the image display light Lf overlap each other, whereby the light flux of the image display light that is 15.3% of the light flux of the image display light L is guided toward the observer.
In this way, each of the emission surfaces 42 a, 42 b, 42 c, 52 a, 52 b, 52 c reflects the image display light L, so that the display region (X ₁ × X) is outside the first light guide 4 and the second light guide 5. Y ₁ ) image display light L is emitted. As a result, the image display light L emitted from the emission mechanism S is guided to the observer's eye E via the first light guide 4 and the second light guide 5.
In addition, since the observer visually recognizes the outside through the emission surfaces 42a to 42c of the first light guide 4 and the emission surfaces 52a to 52c of the second light guide 5, the transmittance of the outside light is uniform 81%.

  As described above, according to the glasses-type display 1, it is possible to suppress the occurrence of luminance unevenness between the virtual image observed by the observer and the outside world.

<Embodiment 2>
FIG. 2 is an optical path diagram showing a schematic configuration of a glasses-type display (display device) according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the thing similar to the spectacles type display 401 mentioned above.
The glasses-type display 101 includes a unit unit U that emits image display light L, a first light guide 104 and a first light guide 104 that are substrates that guide the image display light L from the unit unit U to the eye E of the observer while internally reflecting the unit. Two light guides 105, a unit portion U, a first light guide 104, and a frame portion F to which the second light guide 105 is attached.
The second light guide 105 is disposed in front of the first light guide 104 (Z direction).
The unit unit U forms an image to be a display region (X ₁ × Y ₁ ) on a surface perpendicular to the emission direction, and has a transmission type liquid crystal display (display element) 102 that emits image display light L. A mechanism S and an optical system 3 that forms a virtual image to be observed are provided.
The emission mechanism S includes a light source (not shown) and a transmissive liquid crystal display 102. The transmissive liquid crystal display 102 forms an image to be a display area (X ₁ × Y ₁ ) on a surface perpendicular to the emission direction based on an image signal from a control unit (not shown), and the S polarized light. The image display light L is emitted.

The first light guide 104 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end and is disposed in front of the emission mechanism S (Z direction), and has a planar polarization beam splitter surface 141 at one end. The formed planar total reflection surface 144, the planar polarization conversion surface 145 formed between the total reflection surface 144 and the polarization beam splitter surface 141, and the planar total reflection formed at the other end. The surface (guide surface) 143, the exit surface 142 formed between the polarization beam splitter surface 141 and the total reflection surface 143 and disposed in front of the observer's eye E (Z direction), and the interface between the air and the entire surface. A side surface group 146 formed between the reflection surface 144 and the total reflection surface 143 is included.
The side group 146 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 146a, a second surface 146b facing the first surface 146a in the Z direction, and a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction.

The emission surface 142 includes a planar first emission surface 142a, a planar second emission surface 142b, and a planar third emission surface 142c. And it arrange | positions so that it may become the 1st output surface 142a, the 2nd output surface 142b, and the 3rd output surface 142c in order in a X direction (setting direction). Furthermore, the angle of the first emission surface 142a with respect to the X direction (setting direction), the angle of the second emission surface 142b with respect to the X direction, and the angle of the third emission surface 142c with respect to the X direction are the same as seen from the Y direction. ₁ is arranged.
The first emission surface 142a, the second emission surface 142b, and the third emission surface 142c reflect 19% of the incident light flux of the image display light L and transmit 81% of the light flux of the image display light L. It is possible.

The polarization beam splitter surface 141 has a function of reflecting the S-polarized image display light L and transmitting the P-polarized image display light L.
The polarization conversion surface 145 has a function of converting the S-polarized image display light L into the P-polarized image display light L.
Total reflection surface 143 is arranged last in the X direction (setting direction). The total reflection surface 143 can reflect the incident image display light L toward the second light guide 105. As a result, the image display light L that has transmitted through all the emission surfaces of the first emission surface 142a, the second emission surface 142b, and the third emission surface 142c is guided toward the second light guide 105.

The second light guide 105 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end portion and is disposed in front of the total reflection surface 143 (in the Z direction), and the other end portion. And a group of side surfaces 156 formed between the total reflection surface 153 and the total reflection surface 154 by an interface with air, and a planar total reflection surface 154 formed in front of the total reflection surface 144 (Z direction). And have.
The side group 156 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 156a, a second surface 156b facing the first surface 156a in the Z direction, a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction. And it arrange | positions so that the 2nd surface 156b of the 2nd light guide 105 and the 2nd surface 146b of the 1st light guide 104 may oppose.

In such a glasses-type display 101, the polarization beam splitter surface 141 of the first light guide 104 causes the image display light L in the S-polarized display area (X ₁ × Y ₁ ) from the optical system 3 to move in the substantially X direction. Reflect. The first surface 146a and the second surface 146b guide the image display light L in the display area (X ₁ × Y ₁ ) to the first emission surface 142a while alternately reflecting the image display light L a plurality of times. Therefore, the first emission surface 142a reflects 19% of the incident light beam of the image display light L and transmits 81% of the light beam of the image display light L. That is, the light flux of the image display light La that is 19.0% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 142a reaches the second emission surface 142b. Therefore, the second exit surface 142b reflects 19% of the incident light flux of the image display light L and transmits 81% of the light flux of the image display light L. That is, the light flux of the image display light Lb that is 15.4% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 142b reaches the third emission surface 142c. Therefore, the third exit surface 142c reflects 19% of the incident light flux of the image display light L and transmits 81% of the light flux of the image display light L. That is, the light flux of the image display light Lc that is 12.5% of the light flux of the image display light L is guided toward the observer.
Thereafter, the image display light L transmitted through the third emission surface 142 b reaches the total reflection surface 143. Therefore, the total reflection surface 143 reflects the incident image display light L toward the total reflection surface 153 of the second light guide 105.

The total reflection surface 153 of the second light guide 105 reflects the image display light L in the display area (X ₁ × Y ₁ ) from the first light guide 104 in a substantially −X direction. The first surface 156a and the second surface 156b guide the image display light L in the display region (X ₁ × Y ₁ ) to the total reflection surface 154 while alternately reflecting the image display light L a plurality of times. Therefore, the total reflection surface 154 reflects the incident image display light L toward the total reflection surface 144 of the first light guide 104. Thereafter, the total reflection surface 144 of the first light guide 104 reflects the image display light L substantially in the X direction and guides it to the polarization conversion surface 145. Therefore, the polarization conversion surface 145 converts the image display light L in the S-polarized display area (X ₁ × Y ₁ ) into the image display light L in the P-polarized display area (X ₁ × Y ₁ ). As a result, the image display light L that has passed through the polarization conversion surface 145 passes through the polarization beam splitter surface 141 and reaches the exit surface 142 of the first light guide 104 again as described above. That is, when the first image display light La and the second image display light La overlap, the light flux of the image display light that is 29.1% of the light flux of the image display light L is guided toward the observer. It will be. Further, since the first image display light Lb and the second image display light Lb overlap, the light flux of the image display light that is 23.6% of the light flux of the image display light L is guided toward the observer. It will be. Further, since the first image display light Lc and the second image display light Lc overlap each other, the light flux of the image display light that is 19.1% of the light flux of the image display light L is guided toward the observer. It will be.
As described above, each of the emission surfaces 142a, 142b, and 142c reflects the image display light L, so that the image display light L in the display region (X ₁ × Y ₁ ) is emitted outside the first light guide 104. As a result, the image display light L emitted from the emission mechanism S is guided to the observer's eye E via the first light guide 104.
In addition, since the observer visually recognizes the outside through the emission surfaces 142a to 142c of the first light guide 104, the transmittance of the outside light is uniform 81%.

  As described above, according to the glasses-type display 101, the luminance of the virtual image observed by the observer can be increased.

<Embodiment 3>
FIG. 3 is an optical path diagram showing a schematic configuration of a glasses-type display (display device) according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the thing similar to the spectacles type display 101 mentioned above.
The glasses-type display 201 includes a unit unit U that emits the image display light L, a first light guide 104 that is a substrate that guides the image display light L from the unit unit U to the observer's eye E, and the first light guide 104 and the second light guide 104. Two light guides 205, a unit portion U, a first light guide 104, and a frame portion F to which the second light guide 205 is attached.
The second light guide 205 is disposed in front of the first light guide 104 (Z direction).

The second light guide 205 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end and is disposed in front of the total reflection surface 143 (in the Z direction), and the other end. A planar total reflection surface 254 formed in front of the total reflection surface 144 (Z direction) and formed between the total reflection surface 253 and the total reflection surface 254 (in front of the observer's eye E (Z And a side surface group 256 formed between the total reflection surface 253 and the total reflection surface 254 by an interface with air.
The side group 256 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 256a, a second surface 256b facing the first surface 256a in the Z direction, and a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction. And it arrange | positions so that the 2nd surface 256b of the 2nd light guide 205 and the 2nd surface 146b of the 1st light guide 104 may oppose.

The emission surface 252 includes a planar first emission surface 252c, a planar second emission surface 252b, and a planar third emission surface 252a. And it arrange | positions so that it may become the 1st output surface 252c, the 2nd output surface 252b, and the 3rd output surface 252a in order in -X direction (opposite setting direction). Furthermore, the angle of the first emission surface 252c with respect to the X direction (setting direction), the angle of the second emission surface 252b with respect to the X direction, and the angle of the third emission surface 252a with respect to the X direction are the same as viewed from the Y direction. ₂ are arranged.
The first emission surface 252c, the second emission surface 252b, and the third emission surface 252a reflect 10% of the incident light flux of the image display light L and transmit 90% of the light flux of the image display light L. It is possible.

  The total reflection surface 254 is disposed last in the −X direction (opposite setting direction). The total reflection surface 254 can reflect the incident image display light L toward the first light guide 104. As a result, the image display light L that has transmitted through all the emission surfaces 252 of the first emission surface 252c, the second emission surface 252b, and the third emission surface 252a is reflected toward the first light guide 104. .

In such a glasses-type display 201, the polarization beam splitter surface 141 of the first light guide 104 causes the image display light L in the S-polarized display region (X ₁ × Y ₁ ) from the optical system 3 to move in the approximately X direction. Reflect. The first surface 146a and the second surface 146b guide the image display light L in the display area (X ₁ × Y ₁ ) to the first emission surface 142a while alternately reflecting the image display light L a plurality of times. Therefore, the first exit surface 142a reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light La that is 10% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 142a reaches the second emission surface 142b. Therefore, the second emission surface 142b reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Lb that is 9% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 142b reaches the third emission surface 142c. Therefore, the third emission surface 142c reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Lc that is 8.1% of the light flux of the image display light L is guided toward the observer.
Thereafter, the image display light L transmitted through the third emission surface 142 b reaches the total reflection surface 143. Therefore, the total reflection surface 143 reflects the incident image display light L toward the total reflection surface 253 of the second light guide 205.

The total reflection surface 253 of the second light guide 205 reflects the image display light L in the display area (X ₁ × Y ₁ ) from the first light guide 104 in a substantially −X direction. The first surface 256a and the second surface 256b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first emission surface 252c while alternately reflecting the image display light L a plurality of times. Therefore, the first emission surface 252c reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Ld that is 6.6% of the light flux of the image display light L is guided toward the observer through the third emission surface 142 c of the first light guide 104. At this time, since the image display light Ld and the image display light Lc overlap, the light beam of the image display light that is 14.7% of the light beam of the image display light L is guided toward the observer. Further, the image display light L transmitted through the first emission surface 252c reaches the second emission surface 252b. Therefore, the second emission surface 252b reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light beam of the image display light Le that is 5.9% of the light beam of the image display light L is guided toward the observer through the second emission surface 142b of the first light guide 104. At this time, since the image display light Lb and the image display light Le overlap, the light flux of the image display light that is 14.9% of the light flux of the image display light L is guided toward the observer. Further, the image display light L transmitted through the second emission surface 252b reaches the third emission surface 252a. Therefore, the third emission surface 252a reflects 10% of the incident light flux of the image display light L and transmits 90% of the light flux of the image display light L. That is, the light flux of the image display light Lf, which is 5.3% of the light flux of the image display light L, is guided toward the observer through the first emission surface 142a of the first light guide 104. At this time, the image display light La and the image display light Lf overlap each other, whereby the light flux of the image display light that is 15.3% of the light flux of the image display light L is guided toward the observer.

Thereafter, the image display light L that has passed through the third emission surface 252 a reaches the total reflection surface 254. Therefore, the total reflection surface 254 reflects the incident image display light L toward the total reflection surface 144 of the first light guide 104. As a result, the total reflection surface 144 of the first light guide 104 reflects the image display light L substantially in the X direction, and reaches the emission surface 142 of the first light guide 104 again as described above. That is, the first image display light La, Lf and the second image display light La, Lf overlap each other, so that the light flux of the image display light that is 23.5% of the light flux of the image display light L is given to the observer. It will be guided towards. Further, the first image display light Lb, Le overlaps the second image display light Lb, Le, so that the luminous flux of the image display light L is increased. The light flux of the image display light that is 22.8% is guided toward the observer. Furthermore, the first image display light Lc, Ld and the second image display light Lc, Ld overlap each other, so that the light flux of the image display light that is 22.5% of the light flux of the image display light L is given to the observer. It will be guided towards.
In this way, each of the exit surfaces 142a, 142b, 142c, 252a, 252b, and 252c reflects the image display light L, so that the display area (X ₁ × X) is outside the first light guide 104 and the second light guide 205. Y ₁ ) image display light L is emitted. As a result, the image display light L emitted from the emission mechanism S is guided to the observer's eye E via the first light guide 104 and the second light guide 205.
In addition, since the observer visually recognizes the outside through the exit surfaces 142a to 142c of the first light guide 104 and the exit surfaces 252a to 252c of the second light guide 205, the transmittance of the outside light is uniform 81%.

  As described above, according to the glasses-type display 201, it is possible to suppress the occurrence of luminance unevenness between the virtual image observed by the observer and the outside world.

<Embodiment 4>
FIG. 4 is an optical path diagram showing a schematic configuration of a glasses-type display (display device) according to an embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the thing similar to the spectacles type display 401 mentioned above.
The eyeglass-type display 301 includes a unit unit U that emits image display light L, a first light guide 304 and a first light guide 304 that are substrates that guide the image display light L from the unit unit U to the eye E of the observer while internally reflecting the unit. Two light guides 305, a unit portion U, a first light guide 304, and a frame portion F to which the second light guide 305 is attached.
The second light guide 305 is disposed in front of the first light guide 304 (Z direction).

The first light guide 304 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end portion and is formed at the other end portion with a planar diffractive surface 341 disposed in front of the emission mechanism S (Z direction). A plane-shaped diffractive surface 343, and a plane-shaped diffractive surface (outgoing surface) 342 formed between the diffractive surface 341 and the diffractive surface 343 and disposed in front of the observer's eye E (Z direction); It has a side group 346 formed between the diffractive surface 341 and the diffractive surface 343 by an interface with air.
The side group 346 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 346a, a second surface 346b facing the first surface 346a in the Z direction, and a third surface a (not shown). And a fourth surface (not shown) facing the third surface in the Y direction.

The diffractive surface 341 is formed on the second surface 346b, and can guide the incident image display light L substantially in the X direction (setting direction).
The diffractive surface 342 is formed on the second surface 346b, and guides 10% of the incident light flux of the image display light L toward the observer and allows regular reflection of 90% of the light flux of the image display light L. It has become.
The diffractive surface 343 is formed on the second surface 346b and is arranged at the end (back side) in the X direction (setting direction). The diffractive surface 343 can guide the incident image display light L toward the second light guide 305. As a result, the image display light L that has not been guided toward the observer by the diffractive surface 342 is guided toward the second light guide 305.

The second light guide 305 has a flat plate shape made of polycarbonate (refractive index ng), is formed at one end and is disposed in front of the diffractive surface 343 (Z direction), and the observer's eyes E A diffractive surface (outgoing surface) 352 having a planar shape disposed in front of (Z direction) and a side group 356 formed by an interface with air.
The side group 356 has a quadrangular shape when viewed from the X direction (setting direction), a first surface 356a, a second surface 356b facing the first surface 356a in the Z direction, a third surface (not shown), It has a fourth surface (not shown) facing the third surface in the Y direction. And it arrange | positions so that the 2nd surface 356b of the 2nd light guide 305 and the 2nd surface 346b of the 1st light guide 304 may oppose.

The diffractive surface 353 is formed on the second surface 356b, and can guide the incident image display light L substantially in the −X direction (opposite setting direction).
The diffractive surface 352 is formed on the second surface 356b, and can guide 10% of the incident light flux of the image display light L toward the observer and can regularly reflect 90% of the light flux of the image display light L. It has become.

In such a glasses-type display 301, the diffractive surface 341 of the first light guide 304 reflects the image display light L in the display region (X ₁ × Y ₁ ) from the optical system 3 in the substantially X direction. The first surface 346a and the second surface 346b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first portion of the diffractive surface 342 while alternately reflecting the image display light L a plurality of times. Therefore, the first portion of the diffractive surface 342 guides 10% of the incident light flux of the image display light L toward the observer and regularly reflects 90% of the light flux of the image display light L. In addition, the image display light L reflected from the diffractive surface 342 reaches the second portion of the diffractive surface 342. Therefore, the second portion of the diffractive surface 342 guides 10% of the incident light flux of the image display light L toward the observer, and regularly reflects 90% of the light flux of the image display light L. Further, the image display light L specularly reflected by the second part of the diffractive surface 342 reaches the next part of the diffractive surface 342.
Thereafter, the image display light L that has passed through the diffractive surface 342 reaches the diffractive surface 343. Therefore, the diffractive surface 343 guides the incident image display light L toward the diffractive surface 353 of the second light guide 305.

The diffractive surface 353 of the second light guide 305 reflects the image display light L in the display region (X ₁ × Y ₁ ) from the first light guide 304 in a substantially −X direction. The first surface 356a and the second surface 356b guide the image display light L in the display region (X ₁ × Y ₁ ) to the first portion of the diffraction surface 352 while alternately reflecting the image display light L a plurality of times. Therefore, the first portion of the diffractive surface 352 guides 10% of the incident light flux of the image display light L toward the observer and regularly reflects 90% of the light flux of the image display light L. At this time, the light flux of the image display light in which the image display light Ld and the image display light Lc overlap is guided toward the observer. Further, the image display light L reflected from the first portion of the diffractive surface 352 reaches the second portion of the diffractive surface 352. Therefore, the second portion of the diffractive surface 352 guides 10% of the incident light flux of the image display light L toward the observer and regularly reflects 90% of the light flux of the image display light L. At this time, the light flux of the image display light L in which the image display light Lb and the image display light Le overlap is guided toward the observer. Further, the image display light L specularly reflected by the second part of the diffractive surface 352 reaches the next part of the diffractive surface 352.
In this way, the diffraction surfaces 342 and 352 reflect the image display light L, so that the image display light L in the display region (X ₁ × Y ₁ ) is outside the first light guide 304 and the second light guide 305. Is emitted. As a result, the image display light L emitted from the emission mechanism S is guided to the observer's eye E via the first light guide 304 and the second light guide 305.
Since the observer visually recognizes the outside through the diffraction surface 342 of the first light guide 304 and the diffraction surface 352 of the second light guide 305, the transmittance of the outside light is uniform 81%.

  As described above, according to the glasses-type display 301, it is possible to suppress the occurrence of luminance unevenness between the virtual image observed by the observer and the outside world.

(Other embodiments)
The above-described glasses-type display is mounted on the body of an observer's head and arms, a helmet or glasses worn on the body via a headset, a belt, a band, a clip, or the like, or a mobile phone or a wristwatch. It may be attached to various portable devices such as or may be used while being held in the hand. Moreover, it is not limited to a form such as a head-mounted display attached to the observer, but may be a form such as a head-up display installed in front of the observer.
The transmissive liquid crystal display may be one that forms a color image by incorporating a color filter, or one that forms a monochrome image without a color filter.
In addition, a monochrome image for R (red), G (green), and B (blue) driven by a field sequential drive with a light source that emits light of three colors R (red), G (green), and B (blue) in a time-sharing manner. In combination with a transmissive liquid crystal display that forms time-division, a virtual image to be observed may be displayed in color.

Further, as the display element, a self-luminous display that directly emits image display light may be used, or the display element is configured by a reflective display and an element for illuminating the reflective display. Also good.
Further, the image display light may be guided to both eyes of the observer.
Further, in the above-described glasses-type display, the configuration in which the X direction and the setting direction match is shown, but the configuration in which the X direction and the setting direction do not match may be used, and the Y direction and the setting direction match. The setting direction may be an arbitrary direction.
Examples of the material for forming the light guide include polycarbonate, polymethacrylic acid (PMMA), cycloolefin, and glass material.
A medium having a refractive index lower than that of the first light guide and the second light guide may be disposed between the first light guide and the second light guide.
Further, the diffractive surfaces 342 and 352 of the first light guide 304 and the second light guide 305 may be formed on the first surface (346a, 356a).

  The present invention can be used for information equipment and the like used in an environment other than the desktop.

1, 101, 201, 301, 401 Eyeglass-type display (display device)
2,102 Transmission type liquid crystal display (display element)
3 Optical system 4, 104, 304 1st light guide 5, 105, 205, 305 2nd light guide 42, 142 Output surface 342 Diffraction surface (output surface)
42a, 142a First exit surface 42b, 142b Second exit surface 42c, 142c Third exit surface 43, 143, 343 Total reflection surface (guidance surface)
46a, 146a, 346a First surface 46b, 146b, 346b Second surface 52, 252 Emission surface 352 Diffraction surface (emission surface)
52a, 252a Third exit surface 52b, 252b Second exit surface 52c, 252c First exit surface 56a, 156a, 256a, 356a First surface 56b, 156b, 256b, 356b Second surface L Image display light E Eye of observer S Output mechanism U Unit part

Claims (7)

An emission mechanism having a display element for forming an image to be a display area and emitting image display light;
An optical system that reflects or transmits image display light to form a virtual image of an observation object;
An image from the optical system on the first surface and / or the second surface has a first surface, a second surface facing the first surface, and an exit surface disposed in front of the eyes of the observer A display device comprising a first light guide that guides display light to an exit surface while reflecting display light in a setting direction, and guides image display light from the exit surface to an observer's eye,
With a second light guide,
The first light guide has a guide surface that guides image display light to the second light guide on the back side of the emission surface of the first light guide in the setting direction,
The second light guide has a first surface, a second surface facing the first surface, and an exit surface arranged in front of the eyes of the observer, and the first surface and / or the second surface. Guiding the image display light from the first light guide to the exit surface while reflecting the image display light from the first light guide to the opposite setting direction opposite to the setting direction, guiding the image display light from the exit surface to the observer's eyes,
A display device, wherein the image display light from the exit surface of the first light guide and the image display light from the exit surface of the second light guide are guided to the eyes of the observer so as to overlap each other. An emission mechanism having a display element for forming an image to be a display area and emitting image display light;
An optical system that reflects or transmits image display light to form a virtual image of an observation object;
An image from the optical system on the first surface and / or the second surface has a first surface, a second surface facing the first surface, and an exit surface disposed in front of the eyes of the observer A display device comprising a first light guide that guides display light to an exit surface while reflecting display light in a setting direction, and guides image display light from the exit surface to an observer's eye,
With a second light guide,
The first light guide has a guide surface that guides image display light to the second light guide on the back side of the emission surface of the first light guide in the setting direction,
The second light guide has a first surface, a second surface facing the first surface, and a guide surface, and the first surface and / or the second surface displays an image from the first light guide. A display characterized in that light is guided to a guide surface while reflecting light in an opposite setting direction opposite to the setting direction, and image display light is guided from the guide surface to the front side of the exit surface of the first light guide in the setting direction. apparatus.   The second light guide has a guide surface that guides image display light to the front side of the emission surface of the first light guide in the setting direction on the back side of the emission surface of the second light guide in the opposite setting direction. The display device according to claim 1. The exit surface of the first light guide has N exit surfaces so as to be in order in the setting direction,
The exit surface of the second light guide has N exit surfaces to be in order in the opposite setting direction,
The image display light from the nth exit surface of the first light guide and the image display light from the (N + 1−n) th exit surface of the second light guide overlap so that the observer The display device according to claim 1, wherein the display device is guided to the eyes.   5. The display device according to claim 4, wherein the N exit surfaces of the first light guide and the N exit surfaces of the second light guide have the same reflectance.   4. The display device according to claim 1, wherein an emission surface of the first light guide and the second light guide is a diffraction surface. 5. The display element emits P-polarized light or S-polarized image display light,
The first light guide has a polarization conversion surface to which image display light from the second light guide is guided and an image display light from the display element on the front side of the emission surface of the first light guide in the setting direction. The display device according to any one of claims 2 to 6, further comprising a guided polarization beam spirit surface in this order.

Images