JP7063565B2 - Optical devices suitable for display / lighting and their driving methods - Google Patents

Description

The present invention relates to an optical device and a driving method thereof, and to an optical device suitable for display / illumination and a driving method thereof, which can form a particularly deep image space.

When the first and second mirror members are arranged facing each other and the light source arranged between them is turned on like a mirror, the light rays emitted from the light source are reflected multiple times between the first and second mirror members. .. If at least one of the facing mirror members is a semi-transmissive mirror, multiple reflected light can be observed through the semi-transmissive mirror, and display / illumination with a depth that attracts the attention of the observer can be performed (for example, Patent Document 1). ).

As shown in FIG. 6A, the first mirror member 102, which is a semi-transmissive mirror, and the second mirror member 103, which is a total reflection mirror, are supported in parallel via the cylindrical support member 104, and between them. An optical member 101 in which a plurality of light sources 105 are arranged is formed. The light beam emitted from the light source 105 can be multiple-reflected between the first and second mirror members 102 and 103. When the observer 106 observes the optical member 101 from the side of the first mirror member 102, which is a semi-transmissive mirror, the observer 106 can observe each light beam that is repeatedly reflected.

FIG. 6B is a plan view showing how the light source image looks when the optical member 101 is observed from the central portion of the first mirror member 102, which is a transflective mirror. A plurality of light source images 105g are observed from the position where the light source is actually arranged toward the center. The outermost light source image is a light beam that has passed through the first mirror member 102, which is a semi-transmissive mirror, without being reflected after emitting the light source, and is an image of the light source itself. The light beam emitted through the multiple reflections by the first reflecting member and the second reflecting member forms a light source image which is a virtual image. Depending on the number of multiple reflections, the distance to the light source image, which is a virtual image, increases toward the center, and the diameter thereof decreases. There is a dark part in the center where there is no light source image.

FIG. 6C is a plan view when the observer observes the first mirror member 102 of the optical member 101 from a position deviated from the center of the first mirror member. The position of the light source image and the dark part changes according to the position of the observer.

7A, 7B, and 7C show a configuration in which at least one of the first and second mirror members 102 and 103 has a curved surface shape that protrudes in the direction of the opposing mirror members. In FIG. 7A, the first mirror member 102, which is a semi-transmissive mirror, forms a curved surface that protrudes toward the second mirror member 103. In FIG. 7B, the second mirror member 103, which is a total reflection mirror, forms a curved surface that protrudes toward the first mirror member 102. In FIG. 7C, the first mirror member 102 and the second mirror member 103 form a curved surface that protrudes toward the other.

FIG. 7D is a plan view showing a light source image observed from the central portion of the first mirror member in the case of FIGS. 7A, 7B, and 7C. The light source images are arranged from each light source toward the center, and the size of the dark portion 107 in the center is reduced.

No. 56-139191

When the first and second mirror members, one of which is a semi-transmissive mirror, are arranged facing each other, the light source is arranged between them, and the light source is observed from the mirror member side which is a semi-transmissive mirror, they are arranged in the depth direction by multiple reflection. Multiple light source images can be observed. Multiple reflections can provide a deep field of view. The plurality of light source images are fixed images according to the order of multiple reflections. If the distance in the depth direction, for example, the number of light source images arranged in the depth direction, can be changed, a moving field of view can be provided and the observer's attention can be further drawn.

The display / illumination device according to the embodiment includes a first mirror member which is a semi-transmissive mirror, a second mirror member arranged to face the first mirror member, a first mirror member, and a second mirror. The observer includes a space between the members or a light source arranged on the side thereof, and is equipped with a control device capable of changing the reflectance of at least one of the first mirror member and the second mirror member. Observes from the side of the first mirror member of the first and second mirror members arranged so as to face each other, an image of a light beam directly directed from the light source, and a light beam reflected by the first and second mirror members and then headed. Observe the imaginary image by .

By changing the combined reflectance of the first mirror member and the second mirror member, the depth of the visual field when the observer observes from the first mirror member side can be changed.

and, FIG. 1A is a cross-sectional view showing the movement of a main light beam when a first mirror member and a second mirror member, which are semi-transmissive mirrors, are arranged to face each other, a light source is arranged between them, and the light source is made to emit light. 1B is a cross-sectional view showing the movement of the main light beam when the second mirror member is a transparent body, and FIG. 1C is a cross-sectional view showing the movement of the main light beam when the reflectance of the second mirror member is variable. 1D is a cross-sectional view showing a configuration in which three light sources are arranged between facing substrates, FIG. 1E is a graph showing a change in the brightness of an imaginary image of a light source when the reflectance of a mirror device is changed, and FIG. 1F is a graph. FIG. 1G is a plan view schematically showing a display when the mirror device is turned off, and FIG. 1G is a plan view schematically showing a display when the mirror device is turned on. FIG. 2A is a cross-sectional view schematically showing a configuration of an optical device suitable for display / illumination, and FIG. 2B is a cross-sectional view schematically showing a configuration example in which the mirror device, which is a component of the optical device, is a liquid-phase electro-optical element. Is. FIG. 3A is a graph schematically showing an example of the time change of the drive voltage of the mirror device using the electrolytic solution together with the change of the reflectance, and FIGS. 3B and 3C are virtual images due to the change of the reflectance of the mirror device using the electrolytic solution. It is a graph which shows the change of the brightness of. FIG. 4 is a plan view showing a mirror device having a configuration in which a light source is arranged on a part of a display surface formed by a curved surface. 5A, 5B, and 5C are schematic cross-sectional views showing other configuration examples of the mirror device. FIG. 6A is a perspective view schematically showing a configuration of a display element using multiple reflections between facing substrates according to the prior art, and FIGS. 6B and 6C are plan views showing an example of a light source image displayed on the display element. 7A, 7B, 7C are schematic cross-sectional views showing a configuration in which a curved surface is adopted for the facing substrate, and FIG. 7D is a plan view showing a light source image in which the distribution is changed according to the configuration of FIGS. 7A, 7B, 7C.

1,101 optics, 2,102 (semi-transmissive mirror) first mirror member,
3,103 Second mirror member (with variable reflectance), 5,105 light source,
6,106 Observer, 8 Anti-reflective coating, 9 Control device.

With reference to FIG. 1A, the behavior of the multiple reflected light beam in the configuration in which the light sources are arranged in the space between the first and second mirror members facing each other or on the side thereof will be considered. A semi-transmissive mirror (half mirror) 2 that reflects a part of the light and transmits a part of the light and a total reflection mirror 3 face each other, and a light source 5 is arranged on the side. For simplification, the light source 5 is arranged at a position on the surface of the end of the total reflection mirror 3. The observer 6 observes from the front of the semi-transmissive mirror 2 through which a part of the light is transmitted. The light emitted from the light source 5 is widely distributed, but only the light beam observed by the observer 6 is considered.

The light beam directly directed from the light source 5 to the observer 6 is b1, and the light beam directed to the observer 6 is b2 after being reflected once by the first mirror member 2 and the second mirror member 3, respectively. The light beam directed to the observer 6 after being reflected twice (three times) by the mirror member 2 and the second mirror member 3 is defined as b3 (b4). The virtual images 5-1, 5-2, 5-3 of the light source 5 observed by the light beams b2, b3, and b4 are behind the second mirror member 3, the reciprocating distance between the facing substrates, and twice or three times the same. It is placed in the position of. By observing the virtual image of the light source, the observer feels a field of view with increased depth.

FIG. 1B shows a case where the second mirror member is a transparent body 3t. The light beam traveling from the light source toward the second mirror member becomes transmitted light 3t transmitted through the second mirror member without being reflected by the second mirror member. Multiple reflections do not occur and the depth of the field of view (image space) does not increase.

FIG. 1C shows a case where the reflectance of the second mirror member 3 changes. As shown in the graph shown below the second mirror member 3, the reflectance of the second mirror member gradually increases. Here, as the reflectance increases, the rate of increase, which is the rate of increase, gradually decreases. When the reflectance of the second mirror member increases from zero, a change from the operation of FIG. 1B to the operation of FIG. 1A occurs. As the reflectance of the second mirror member increases, the virtual image of the light source 5 gradually increases. Although the virtual images 5-1, 5-2, 5-3, 5-4 are shown, for example, up to the 10th-order virtual image can be observed. The 10th-order virtual image is recognized at a position 10 times the distance between the facing substrates behind the second mirror member 3, and provides a deep field of view.

FIG. 1E is a graph showing the brightness of the virtual image of the light source as a function of the order of multiple reflections by simulation with the reflectance of the mirror device (second mirror member) as a parameter. As for the order of multiple reflections, one round trip between facing mirror members is set to order 1. If the reflectance is zero, no virtual image will occur. When the reflectance is increased to 20%, 40%, and 60%, for example, 3rd, 5th, and 7th virtual images are recognized, and when the reflectance is 80%, 10th virtual images are also recognized.

FIG. 1D is a cross-sectional view showing a configuration in which three light sources are arranged between the first and second mirror members 2 and 3 facing each other. FIG. 1C shows an example in which one light source is arranged between the facing mirror members 2 and 3, but it is more effective to increase the position of the virtual image in order to clarify the effect of the visual field in which the depth direction is increased. .. In the configuration of FIG. 1D, three light sources are arranged so as to overlap each other in the optical axis direction between the first and second mirror members 2 and 3 facing each other. The number of light sources arranged so as to be stacked within the distance between the facing boards and the distance between the facing boards can be variously changed.

FIG. 1F is a field image observed from the semi-transmissive mirror side when the light sources are triple-arranged between the facing substrates and the mirror device is turned off (reflectance is zero), and FIG. 1G shows a field image observed with the mirror device turned on. The field image observed from the semitransparent mirror side when multiple reflections are generated is shown by using the mirror member of No. 2 as an effective reflecting mirror. By using multiple reflections, it is possible to deepen the depth of the field of view.

FIG. 2A is a cross-sectional view schematically showing the configuration of the optical device 1 suitable for display / illumination. A plurality of light sources 5 formed of light emitting diodes (IEDs) are arranged between the first mirror member 2 which is a semi-transmissive mirror and the second mirror member 3 whose reflectance can be changed. Antireflection films 8 are arranged on both sides of the second mirror member. The second mirror member 3 is an electrochemical element capable of forming a mirror surface such as Ag, and a voltage supplied from the control device 9 is applied. The observer 6 observes the optical device from the side of the first mirror member 2 which is a transflective mirror.

As shown in FIG. 2B, in the second mirror member 3, a pair of transparent substrates 21 and 22 having transparent electrodes 23 and 24 are opposed to each other with the electrodes inside, and a space closed by the sealing material 25 is formed and closed. The structure is such that the electrolytic solution 26 is sealed in the space. The electrolytic solution 26 contains 200 mM AgBr as the Ag salt that precipitates Ag, 800 mM LiBr as the supporting salt, 800 mM TaCl ₅ as the mediator, and gamma-butyl lactone (GBL) as the solvent. When a DC voltage is applied between the transparent electrodes 23 and 24, an Ag layer is deposited on the transparent electrode on the negative station side.

FIG. 3A is a graph showing an applied voltage waveform in the driving example of the above-mentioned optical device 1. A positive voltage Von is applied during the ON period, a negative voltage Voff is applied during the main OFF period, and a ground voltage is applied during the OFF period. During the On period, the Ag layer is deposited on the transparent electrode on the negative electrode side, and during the OFF period, the precipitation layer is dissolved by reversing the applied voltage.

FIG. 3B is a graph showing the brightness with respect to the virtual image order of the light source, with the reflectance of the second mirror member 3 as a parameter. When the reflectance is zero, no virtual image is generated. When the reflectance is 20%, 40%, 60%, and 80%, a virtual image whose brightness decreases as the order increases is formed. With a reflectance of 20%, up to a third-order virtual image can be recognized, with a reflectance of 40%, up to a fifth-order virtual image can be recognized, and with a reflectance of 60%, up to a seventh-order virtual image can be recognized. At a reflectance of 80%, a 10th-order virtual image can be recognized.

FIG. 3C shows the graph of FIG. 3B on a semi-log scale. The content is the same. The change in the low-luminance region is more pronounced than in the linear scale.

The intensity of multiple reflections depends on the reflectance of the opposing first and second mirror members as a whole. Even if the reflectance of the second mirror member is fixed and the reflectance of the first mirror member is changed, the order of multiple reflections changes. That is, it is possible to change the order of multiple reflections by making the reflectance of at least one of the first and second mirror members variable.

When multiple reflections are generated between the first mirror member 2 and the second mirror member 3, the order of the multiple reflections is increased by 1 by making one round trip between the opposing mirror members. Assuming that the distance between the first mirror member 2 and the second mirror member 3 is g, an increase in the order of multiple reflections by 1 means an increase in the depth of the image space by (2 g). When multiple reflections up to the nth order are generated, the depth of the image space becomes 2 (ng), which is 2n times the actual mirror member pole g. In the case of a tail lamp for a vehicle, the distance between the facing mirror members is preferably 1 cm to 50 cm. Considering other requirements and the like, it is more preferable that the distance between the facing mirror members is 2 cm to 30 cm.

FIG. 4 shows an example of an optical device 30 having a curved display surface. Similar to the above example, it has a configuration in which a mirror member capable of changing the reflectance is arranged under the semitransparent mirror. The display surface 31a of the area 1 and the display surface 31b of the area 2 are arranged adjacent to each other vertically, the turn lamp 32 is arranged in the area 1, and the brake lamp 33 is arranged in the area 2. By increasing the reflectance, the multiple reflection order increases with the increase in brightness, and the depth of the image space becomes deeper. Subsequent reductions in reflectance reduce the brightness, reduce the multiple reflection order, and reduce the depth of the image space. Multiple reflections form a reduced size virtual image inside the turn lamp or brake lamp. The change in the virtual image makes it easier for the driver of the following vehicle to recognize the display of the preceding vehicle, which contributes to safe driving.

As a mirror device capable of changing the reflectance, a configuration as described below can be used instead of a variable mirror capable of precipitating / dissolving a mirror layer such as Ag using the above-mentioned electrolytic solution.

In FIG. 5A, a normal polarizing element P1 is arranged on the front side of the liquid crystal element 35, and a reflective polarizing element P2 is arranged on the rear side of the liquid crystal element, and incident light is emitted according to the state of the liquid crystal element 35 controlled by the control device 9. The configuration of reflection and shading is shown. The reflectance can be changed depending on the state of the liquid crystal element. The front-side polarizing element P1 may also be a reflective type polarizing element.

In FIG. 5B, a magnesium / yttrium alloy mirror layer 38 is formed on the surface of the substrate 37, and the mirror layer 38 can be exposed to a hydrogen gas flow 39. The transparent state / mirror state changes depending on the bonding state between the alloy layer and hydrogen. The reflectance can be changed depending on the hydrogen bond state.

FIG. 5C shows a configuration in which the electrochromic cell 43 is arranged in front of the total reflection mirror 42 formed on the substrate 41. When the chromic layer 44 is formed in the electrochromic cell 43, the overall reflectance including the total reflecting mirror 42 decreases. The reflectance as a whole can be changed according to the degree of shading of the chromic layer.

Using these configurations, it would be possible to display the depth of the visual field (image space) by changing the reflectance with respect to the incident light and changing the order of multiple reflections.

Although described above with reference to Examples, the present invention is not limited thereto. For example, it will be obvious to those skilled in the art that various polarizations, improvements, combinations, etc. are possible.

Claims (11)

The first mirror member, which is a semi-transmissive mirror,
A second mirror member arranged to face the first mirror member,
A space between the first mirror member and the second mirror member or a light source arranged on the side thereof,
Including
A control device capable of changing the reflectance of at least one of the first mirror member and the second mirror member is provided.
The observer observes from the first mirror member side of the first and second mirror members arranged to face each other, and is reflected by the image of the light beam directly directed from the light source and the first and second mirror members. After that, observe the virtual image by the heading light beam,
Display / lighting equipment . The first mirror member has a fixed reflectance and has a fixed reflectance.
The display / lighting device according to claim 1 , wherein the control device can change the reflectance of the second mirror member . The display / lighting device according to claim 2, wherein the control device controls the reflectance of the second mirror member so that the reflectance increases and the increase rate of the reflectance decreases . The display / lighting device according to any one of claims 1 to 3, wherein the light source is a plurality of arranged between the first mirror member and the second mirror member . The display / lighting device according to claim 2 or 3 , wherein the second mirror member includes a mirror device capable of precipitating / dissolving a reflecting mirror layer. The mirror device includes a transparent substrate facing the first mirror member, a facing substrate facing the transparent substrate, the transparent substrate, and a facing transparent electrode formed on the facing surface of the facing substrate. 5. The 5 . Display / lighting device . The mirror device includes a transparent substrate facing the first mirror member, a facing substrate facing the transparent substrate, a facing transparent electrode formed on the facing surface of the facing substrate, and the transparency. The display according to claim 5 , further comprising a member for supplying a reaction gas capable of forming / extinguishing a reflecting mirror layer on the facing transparent electrode by an electrochemical reaction in the space between the substrate and the facing substrate. / Lighting device . The display / lighting device according to claim 5 , wherein the mirror device includes a mirror surface, a transparent surface arranged in front of the mirror surface, and a mechanism capable of precipitating / dissolving a light-shielding layer on the transparent surface. The one according to any one of claims 1 to 8 , wherein the display / lighting device forms at least a part of a tail lamp for a vehicle, and the second mirror member is arranged in front of the first mirror member. Display / lighting device . A first mirror member which is a semi-transmissive mirror, a second mirror member arranged to face the first mirror member, and a space or a side thereof between the first mirror member and the second mirror member. A display / lighting device including a light source arranged in the direction and a control device for changing the reflectance of at least one of the first mirror member and the second mirror member is prepared.
Turn on the light source
The reflectance of the second mirror member is changed by the control device, and the reflectance is changed.
The observer observes from the first mirror member side of the first and second mirror members arranged to face each other, and is reflected by the image of the light beam directly directed from the light source and the first and second mirror members. After that, the depth of the field of view is changed by observing the virtual image of the heading light beam .
A method of driving a display / lighting device , characterized in that. The method for driving a display / lighting device according to claim 10 , wherein the reflectance of the second mirror member repeatedly increases and decreases.

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