JP2019066647A - Optical device suitable for display/illumination and method for driving the same - Google Patents

Abstract

To provide an optical device suitable for display/illumination that can change a distance in a depth direction.SOLUTION: An optical device suitable for display/illumination according to an example comprises: a first mirror member that is a semi-transmissive mirror; a second mirror member that is arranged opposite to the first mirror member; and a light source that is arranged in a space between the first mirror member and second mirror member and the periphery of the space. At least one of the first mirror member and second mirror member can change its reflectance.SELECTED DRAWING: Figure 1-1

Description

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

  When the first and second mirror members are disposed opposite to each other and the light source disposed between the two is turned on like a laminated mirror, light rays emitted from the light source are multiply reflected between the first and second mirror members. . If at least one of the opposing 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 can draw 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 a 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 multiply reflected between the first and second mirror members 102 and 103. When observing 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 multi-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 semitransparent 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 transmitted 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. A light beam emitted through multiple reflection by the first reflecting member and the second reflecting member forms a light source image which is a virtual image. According to 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. In the center, there is a dark part where no light source image exists.

  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 positions of the light source image and the dark part are changed corresponding to the position of the observer.

  FIGS. 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 shape that protrudes in the direction of the opposite mirror member. In FIG. 7A, the first mirror member 102, which is a semitransparent 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. In FIG. 7C, the first mirror member 102 and the second mirror member 103 form curved surfaces which project toward each other.

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

Japanese Utility Model Application No. 56-139191

  The first and second mirror members, at least one of which is a semitransparent mirror, are disposed opposite to each other, and the light source is disposed between them, and the light source is observed from the mirror member side which is a semitransparent mirror. Multiple light source images can be observed. Multiple reflections can provide a deep field of view. The plurality of light source images are images fixed according to the order of multiple reflection. 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 visual field can be provided, and the viewer's attention can be drawn.

  An optical apparatus suitable for display / illumination according to an embodiment includes a first mirror member which is a semitransparent mirror, a second mirror member disposed opposite to the first mirror member, a first mirror member, and a second mirror member. And a light source disposed laterally of the space between the mirror members, and at least one of the first mirror member and the second mirror member can change the reflectance.

  By changing the combined reflectance of the first mirror member and the second mirror member, it is possible to change the depth of the visual field when the observer observes from the first mirror member side.

and, FIG. 1A is a sectional view showing the movement of the main light beam when the first mirror member and the second mirror member, which are semitransparent mirrors, are disposed opposite to each other, the light source is disposed between them, and the light source emits 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 light sources are arranged in a triple manner between opposing substrates, FIG. 1E is a graph showing a change in brightness of a virtual image of the light source when the reflectance of the mirror device is changed, FIG. 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 the configuration of an optical device suitable for display / illumination, and FIG. 2B is a cross-sectional view schematically showing a configuration example in which a mirror device which is a component of the optical device is a liquid phase electro-optic element. It is. FIG. 3A is a graph schematically showing an example of the time change of the drive voltage of the mirror device using an electrolytic solution, along with the change of the reflectance; FIGS. 3B and 3C are virtual images due to the change of the reflectance of the mirror device using an electrolytic solution Is a graph schematically showing the change in brightness of the image in the linear scale and the semi-log scale. FIG. 4 is a plan view showing a mirror device having a configuration in which a light source is disposed 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 the configuration of a display device utilizing multiple reflection between opposing substrates according to the prior art, and FIGS. 6B and 6C are plan views showing examples of light source images displayed on the display device. 7A, 7B, and 7C are schematic cross-sectional views showing a configuration in which a curved surface is adopted for the opposite substrate, and FIG. 7D is a plan view showing a light source image in which distribution is changed by the configurations of FIGS. 7A, 7B and 7C.

1, 101 optical device, 2, 102 first mirror member (which is a semi-transmissive mirror),
3, 103 second mirror member (having variable reflectance), 5, 105 light source,
6,106 observers, 8 anti-reflective coatings, 9 controls.

  With reference to FIG. 1A, the behavior of the multiply reflected light beam in the configuration in which the light source is disposed in the space between the first and second opposing mirror members or to the side thereof will be considered. A semi-transmissive mirror (half mirror) 2 that reflects part of the light and transmits part of the light is opposed to the total reflection mirror 3, and a light source 5 is disposed on the side. For the sake of simplicity, it is assumed that the light source 5 is disposed on the end surface of the total reflection mirror 3. The observer 6 observes from the front of the semitransparent mirror 2 through which a part of light passes. Although the light emitted from the light source 5 is widely distributed, only the light beam observed by the observer 6 is considered.

  A light beam directed directly from the light source 5 to the observer 6 is b1, and after being reflected once by each of the first mirror member 2 and the second mirror member 3, a light beam directed to the observer 6 is b2; After each reflecting twice by the mirror member 2 and the second mirror member 3 (three times), the light beam directed to the observer 6 is b3 (b4). The virtual images 5-1, 5, 2 and 5-3 of the light source 5 observed by the light beams b2, b3 and b4 are the back distance of the second mirror member 3, the distance between the opposing substrates, and the double and triple thereof. 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 the 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 the 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 the case where the reflectance of the second mirror member 3 changes. As 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. As the reflectivity 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 virtual images 5-1, 5-2, 5-3 and 5-4 are illustrated, it is possible to observe up to, for example, a 10th-order virtual image. The tenth-order virtual image is recognized behind the second mirror member 3 at a position ten times the distance between the opposing substrates, 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 reflection by simulation using the reflectance of the mirror device (second mirror member) as a parameter. The order of multiple reflection is assumed to be the order 1 for one round trip between the opposing mirror members. If the reflectivity is zero, no virtual image will occur. When the reflectance increases to 20%, 40%, and 60%, for example, third, fifth, and seventh virtual images are recognized, and when the reflectance is 80%, a tenth virtual image is also recognized.

  FIG. 1D is a cross-sectional view showing a configuration in which the light sources are arranged in triple between the opposing first and second mirror members 2 and 3. Although FIG. 1C shows an example in which one light source is disposed between the facing mirror members 2 and 3, it is more effective to increase the position of the virtual image in order to clarify the effect of the field of view in which the depth direction is increased. . In the configuration of FIG. 1D, three light sources are arranged in an overlapping manner in the optical axis direction between the opposing first and second mirror members 2 and 3. The distance between the opposing substrates and the number of light sources disposed overlapping in the distance between the opposing substrates can be changed variously.

  FIG. 1F is a field of view image observed from the semitransparent mirror side in the case where the light source is triplely disposed between the opposing substrates and the mirror device is turned off (reflectance is zero), and FIG. The mirror image of 2 is made into an effective reflecting mirror, and the view-field image observed from the semi-transmission mirror side at the time of making multiple reflection is shown is shown. By using multiple reflections, it is possible to deepen the depth of vision.

  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 disposed between the first mirror member 2 which is a semitransparent mirror and the second mirror member 3 which can change the reflectance. Antireflection films 8 are disposed on both sides of the second mirror member. The second mirror member 3 is an electrochemical element capable of forming a mirror surface of Ag or the like, 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 semitransparent mirror.

As shown in FIG. 2B, the second mirror member 3 has a pair of transparent substrates 21 and 22 having transparent electrodes 23 and 24 facing each other with the electrodes facing inward, forming a closed space with a sealing material 25 and closing it. The electrolytic solution 26 is sealed in the space. The electrolytic solution 26 contains 200 mM AgBr as an Ag salt which precipitates Ag, 800 mM LiBr as a support salt, 800 mM TaCl ₅ as a mediator, and gamma butyl lactone (GBL) as a solvent. When a DC voltage is applied between the transparent electrodes 23 and 24, an Ag layer is deposited on the negative electrode-side transparent electrode.

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

  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 is formed in which the brightness decreases as the order increases. A reflectance of 20% can recognize up to a third virtual image, a reflectance of 40% can recognize up to a fifth virtual image, and a reflectance of 60% can recognize up to a seventh virtual image. A reflectance of 80% can also recognize a 10th-order virtual image.

  FIG. 3C shows the graph of FIG. 3B on a semilog scale. The contents are the same. The change in the low luminance region is more apparent than in the linear scale.

  The intensity of the multiple reflection 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 a fixed reflectance, and the reflectance of the first mirror member is changed, the order of multiple reflection changes. That is, it is possible to change the order of multiple reflection by making the reflectance of at least one of the first and second mirror members variable.

  When multiple reflection is caused between the first mirror member 2 and the second mirror member 3, the order of multiple reflection is increased by 1 by reciprocating 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 reflection means that the depth of the image space is increased by (2 g). When multiple reflections up to the n-th order are generated, the depth of the image space is 2 (ng), which is 2n times the actual inter-mirror member electrode g. In the case of a vehicle tail lamp, the distance between the opposing mirror members may preferably be 1 cm to 50 cm. It is more preferable that the distance between the opposing mirror members be 2 cm to 30 cm in consideration of other requirements and the like.

  FIG. 4 shows an example of the optical device 30 whose display surface is a curved surface. As in the previous example, it has a configuration in which a mirror member capable of changing the reflectance is disposed below the semitransparent mirror. The display surface 31 a of the area 1 and the display surface 31 b of the area 2 are vertically adjacent to each other, the turn lamp 32 is arranged in the area 1, and the brake lamp 33 is arranged in the area 2. By increasing the reflectivity, the order of multiple reflections increases with increasing brightness and the depth of the image space is deeper. Subsequent reductions in reflectivity reduce brightness, reduce multiple reflection orders, and reduce the depth of the image space. The multiple reflections form a reduced-size virtual image inside the turn lamp or the brake lamp. The change of 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, the configuration described below can be used instead of a variable mirror capable of depositing / dissolving a mirror layer of Ag or the like using the above-described electrolytic solution.

  In FIG. 5A, a normal polarizer P1 is disposed on the front side of the liquid crystal element 35, and a reflective polarizer P2 is disposed on the rear side of the liquid crystal element, and incident light is The structure which is reflected and shielded is shown. The reflectance can be changed according to the state of the liquid crystal element. The front polarizer P1 may also be a reflective polarizer.

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

  FIG. 5C shows a configuration in which the electrochromic cell 43 is disposed 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 reflection mirror 42 is reduced. The overall reflectance can be changed according to the degree of light shielding of the chromic layer.

  Using these configurations, it is also possible to change the reflectance to incident light and change the depth of the field of view (image space) by changing the order of multiple reflections.

  Although the embodiments have been described above, the present invention is not limited to these. For example, it will be obvious to those skilled in the art that various polarizations, modifications, combinations etc. are possible.

Claims (12)

A first mirror member which is a semitransparent mirror;
A second mirror member disposed opposite to the first mirror member;
A light source disposed in the space between the first mirror member and the second mirror member or to the side thereof;
An optical apparatus suitable for display / illumination, comprising: at least one of the first mirror member and the second mirror member can change a reflectance.   The optical device suitable for display / illumination according to claim 1, further comprising a control device for changing the reflectance of at least one of the first mirror member and the second mirror member.   An optical apparatus suitable for display / illumination according to claim 1 or 2, wherein said second mirror member comprises a mirror device capable of depositing / dissolving a reflector layer.   The mirror device includes a transparent substrate disposed opposite to the first mirror member, an opposing substrate disposed opposite to the transparent substrate, and an opposing transparent electrode formed on the opposing surface of the transparent substrate and the opposing substrate. The method according to claim 3, further comprising: an electrolyte solution contained in the space between the opposing transparent electrodes, and capable of depositing / dissolving a reflector layer on one of the opposing transparent electrodes by an electrochemical reaction. Optical device suitable for display / lighting.   5. An optical device suitable for display / illumination according to claim 4, further comprising a controller capable of controlling the operation of the mirror device.   The mirror device includes: a transparent substrate disposed to face the first mirror member; an opposing substrate disposed to face the transparent substrate; an opposing transparent electrode formed on an opposing surface of the opposing substrate; The display according to claim 3, comprising: a substrate, and a member for supplying a reaction gas capable of depositing / dissolving a reflecting mirror layer on the counter transparent electrode by an electrochemical reaction in the space between the counter substrate. / Optical device suitable for lighting.   An optical device suitable for display / illumination according to claim 3, wherein said mirror device comprises a mirror surface, a transparent surface arranged in front of the mirror surface, and a mechanism capable of depositing / dissolving a light shielding layer on said transparent surface. .   The display according to any one of claims 1 to 7, wherein the optical device forms at least a part of a vehicle tail lamp, and the second mirror member is disposed in front of the first mirror member. Optical device suitable for lighting.   An optical apparatus suitable for display / illumination according to claim 8, wherein the distance between the first mirror member and the second mirror member is in the range of 1 cm to 50 cm.   The optical device suitable for display / illumination according to claim 9, wherein a distance between the first mirror member and the second mirror member is in a range of 2 cm to 30 cm. A first mirror member which is a semitransparent mirror, a second mirror member disposed opposite to the first mirror member, a space between the first mirror member and the second mirror member or the side thereof Providing an optical device including a light source disposed on one side and a controller for changing the reflectance of at least one of the first mirror member and the second mirror member;
Turn on the light source,
The depth of the field of view is changed by changing the reflectance of the one by the controller.
And a driving method of an optical device suitable for display / illumination.   The method of driving an optical device suitable for display / illumination according to claim 11, wherein the reflectance of said one of the light emission and the light emission is repeatedly increased and decreased.

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