Patent Application
20160077362
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2014-186468, filed on Sep. 12, 2014; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a liquid crystal optical device, a control device of the liquid crystal optical device, and an image display device.
There is a liquid crystal optical device in which the distribution of the refractive index is changed according to an applied voltage by utilizing the birefringence of a liquid crystal. In the liquid crystal optical device, the optical characteristics are controlled by a control device. There is an image display device in which an image display unit is combined with the liquid crystal optical device. The image display unit displays a two-dimensional image or a three-dimensional image including multiple parallax images. By changing the distribution of the refractive index of the liquid crystal optical device, a two-dimensional display and a three-dimensional display for stereoscopic viewing with the naked eyes are performed. An image display device having high display quality is desirable. A liquid crystal optical device having good optical characteristics is desirable.
According to one embodiment, a liquid crystal optical device includes an optical unit and a controller. The optical unit includes a first substrate, a second substrate, a plurality of first electrodes, a first counter electrode, a second counter electrode, and a liquid crystal layer. The first substrate has a first surface including a first region and a second region. The second substrate opposes the first substrate. The first electrodes are provided between the first substrate and the second substrate and arranged in a first direction parallel to the first surface. A first group of the first electrodes overlaps the first region. A second group of the first electrodes overlaps the second region when projected onto the first surface. The first counter electrode is provided between the second substrate and the first electrodes. The first counter electrode and the first region overlap when projected onto the first surface. The second counter electrode is provided between the second substrate and the first electrodes. The second counter electrode and the second region overlap when projected onto the first surface. The liquid crystal layer is provided between the first and the second substrates. The controller controls a voltage applied to the first electrodes, the first counter electrode, and the second counter electrode. The controller is configured to perform a plurality of display modes. The display modes include a first mode and a second mode. The first mode includes forming a first lens in the liquid crystal layer by forming a first potential difference between the first group and the first counter electrode and forming a second lens in the liquid crystal layer by forming a second potential difference between the second group and the second counter electrode. A difference between a maximum value and a minimum value of a refractive index of the first lens is larger than a difference between a maximum value and a minimum value of a refractive index of the second lens. The second mode includes forming a third lens in the liquid crystal layer by forming a third potential difference between the first group and the first counter electrode, and forming a fourth lens in the liquid crystal layer by forming a fourth potential difference between the second group and the second counter electrode. A difference between a maximum value and a minimum value of a refractive index of the third lens is larger than a difference between a maximum value and a minimum value of a refractive index of the fourth lens.
According to another embodiment, an image display device includes a liquid crystal optical device and an image display unit. The liquid crystal optical device includes an optical unit and a controller. The optical unit includes a first substrate, a second substrate, a plurality of first electrodes, a first counter electrode, a second counter electrode, and a liquid crystal layer. The first substrate has a first surface including a first region and a second region. The second substrate opposes the first substrate. The first electrodes are provided between the first substrate and the second substrate and arranged in a first direction parallel to the first surface. A first group of the first electrodes overlaps the first region. A second group of the first electrodes overlaps the second region when projected onto the first surface. The first counter electrode is provided between the second substrate and the first electrodes. The first counter electrode and the first region overlap when projected onto the first surface. The second counter electrode is provided between the second substrate and the first electrodes. The second counter electrode and the second region overlap when projected onto the first surface. The liquid crystal layer is provided between the first and the second substrates. The controller controls a voltage applied to the first electrodes, the first counter electrode, and the second counter electrode. The controller is configured to perform a plurality of display modes. The display modes include a first mode and a second mode. The first mode includes forming a first lens in the liquid crystal layer by forming a first potential difference between the first group and the first counter electrode and forming a second lens in the liquid crystal layer by forming a second potential difference between the second group and the second counter electrode. A difference between a maximum value and a minimum value of a refractive index of the first lens is larger than a difference between a maximum value and a minimum value of a refractive index the second lens. The second mode includes forming a third lens in the liquid crystal layer by forming a third potential difference between the first group and the first counter electrode and forming a fourth lens in the liquid crystal layer by forming a fourth potential difference between the second group and the second counter electrode. A difference between a maximum value and a minimum value of a refractive index of the third lens is larger than a difference between a maximum value and a minimum value of a refractive index of the fourth lens.
According to another embodiment, a control device controls a liquid crystal optical device. The liquid crystal optical device includes an optical unit including a first substrate, a second substrate, a plurality of first electrodes, a first counter electrode, a second counter electrode, and a liquid crystal layer. The first substrate has a first surface including a first region and a second region. The second substrate opposes the first substrate. The first electrodes are provided between the first substrate and the second substrate and arranged in a first direction parallel to the first surface. The first group of the first electrodes overlaps the first region. The second group of the first electrodes overlaps the second region when projected onto the first surface. The first counter electrode is provided between the second substrate and the first electrodes. The first counter electrode and the first region overlap when projected onto the first surface. A second counter electrode is provided between the second substrate and the first electrodes. The second counter electrode and the second region overlap when projected onto the first surface. The liquid crystal layer is provided between the first and the second substrates. The control device controls a voltage applied to the first electrodes, the first counter electrode, and the second counter electrode. The control device is configured to perform a plurality of display modes. The display modes include a first mode and a second mode. The first mode includes forming a first lens in the liquid crystal layer by forming a first potential difference between the first group and the first counter electrode, and forming a second lens in the liquid crystal layer by forming a second potential difference between the second group and the second counter electrode. A difference between a maximum value and a minimum value of a refractive index of the first lens is larger than a difference between a maximum value and a minimum value of a refractive index of the second lens. The second mode includes forming a third lens in the liquid crystal layer by forming a third potential difference between the first group and the first counter electrode, and forming a fourth lens in the liquid crystal layer by forming a fourth potential difference between the second group and the second counter electrode. A difference between a maximum value and a minimum value of a refractive index of the third lens is larger than a difference between a maximum value and a minimum value of a refractive index of the fourth lens.
Various embodiments will now be described hereinafter with reference to the accompanying drawings.
The drawings are schematic or conceptual; and the relationships between the thicknesses and widths of portions, the proportions of sizes between portions, etc., are not necessarily the same as the actual values thereof. Further, the dimensions and/or the proportions may be illustrated differently between the drawings, even in the case where the same portion is illustrated.
In the drawings and the specification of the application, components similar to those described in regard to a drawing thereinabove are marked with like reference numerals, and a detailed description is omitted as appropriate.
The image display device 510 includes a liquid crystal optical device 110 and an image display unit 400. The liquid crystal optical device 110 includes an optical unit 105 and a controller 150 (a control device). The image display unit 400 is stacked with the optical unit 105. The image display unit 400 includes, for example, an image display drive unit 450.
In the specification of the application, the state of being stacked includes not only the state of overlapping in direct contact but also the state of being provided to overlap with spacing therebetween and the state of overlapping with another component inserted therebetween.
The controller 150 includes an input unit 152, a processor 151, a circuit unit 106, and a power supply unit 153.
For example, image information Id (an image signal) is input to the input unit 152. The image information Id is supplied to the image display drive unit 450. The image display unit 400 performs the display based on the image information Id. A control signal Sc may be further input to the input unit 152. The control signal Sc is, for example, a signal due to an operation of a user (a viewer).
The image information Id is supplied to the processor 151. The processor 151 performs processing based on the image information Id. The circuit unit 106 operates based on the processing result of the processor 151.
The circuit unit 106 includes, for example, a voltage generator 103, a switch circuit 103s, a first circuit unit 107a, and a second circuit unit 107b. For example, the voltage generator 103 generates multiple potentials from the voltage (the electrical power) supplied from the power supply unit 153. In the example, the voltage generator 103 includes first to fourth voltage generators 103a to 103d.
For example, the first voltage generator 103a generates a first electrode high potential Veh1, a first electrode low potential Vel1, a first counter high potential Vch1, and a first counter low potential Vc11.
For example, the second voltage generator 103b generates a second electrode high potential Veh2, a second electrode low potential Vel2, a second counter high potential Vch2, and a second counter low potential Vcl2.
For example, the third voltage generator 103c generates a third electrode high potential Veh3, a third electrode low potential Vel3, a third counter high potential Vch3, and a third counter low potential Vcl3.
For example, the fourth voltage generator 103d generates a fourth electrode high potential Veh4, a fourth electrode low potential Vel4, a fourth counter high potential Vch4, and a fourth counter low potential Vcl4. The fourth electrode high potential Veh4, the fourth electrode low potential Vel4, the fourth counter high potential Vch4, and the fourth counter low potential Vcl4 may be 0 volts (V).
The switch circuit 103s switches between these potentials and supplies these potentials to the first circuit unit 107a and the second circuit unit 107b. The first circuit unit 107a supplies a high voltage Veh and a low voltage Vel to the optical unit 105. The second circuit unit 107b supplies a high common voltage Vch and a low common voltage Vcl to the optical unit 105. As described below, the distribution of the refractive index in a light control region 105d of the optical unit 105 changes according to these voltages.
The processor 151 includes an information acquisition unit 151a, a region determination unit 151b, a flagging unit 151c, an evaluation value calculator 151d, and a voltage determination unit 151e. The information acquisition unit 151a acquires the image information Id (information of the display content). The region determination unit 151b determines the region inside the display region where a three-dimensional (3D) image is displayed. For example, a region (a 2D region) where a two-dimensional (2D) image is displayed and a region (a 3D region) where a three-dimensional image is displayed are provided inside a screen 400d of the image display unit 400. The region determination unit 151b determines these regions. The flagging unit 151c provides flag bits in the row direction and column direction of the light control region 105d. This is described below. The evaluation value calculator 151d calculates an evaluation value (a weight) for the 2D region and the 3D region based on the display content. The voltage determination unit 151e determines, based on the evaluation value, appropriate combinations from the combinations of the various potentials generated by the voltage generator 103. The switch circuit 103s switches the potentials according to the determination of the voltage determination unit 151e.
The information acquisition unit 151a, the region determination unit 151b, the flagging unit 151c, the evaluation value calculator 151d, and the voltage determination unit 151e are a functional block and correspond to the processing implemented by the processor 151. At least a portion of the processing may be implemented simultaneously or may be implemented at different times. The processor 151 includes, for example, a semiconductor integrated circuit, etc.
As shown in
The first substrate unit 10u includes a first substrate 10s and multiple first electrodes 11.
The first substrate 10s is light-transmissive. The first substrate 10s has a first surface 10a. The first surface 10a includes, for example, a first region R1 and a second region R2.
The multiple first electrodes 11 are arranged in a first direction D1. The first direction D1 is one direction parallel to the first surface 10a.
A direction perpendicular to the first surface 10a is taken as a Z-axis direction. One direction perpendicular to the Z-axis direction is taken as an X-axis direction. A direction perpendicular to the Z-axis direction and perpendicular to the X-axis direction is taken as a Y-axis direction. The first direction D1 is, for example, the X-axis direction.
For example, each of the multiple first electrodes 11 extends along a first orthogonal direction Da1. The first orthogonal direction Da1 is, for example, the Y-axis direction. The multiple first electrodes 11 include a first group G1 and a second group G2. The first region R1 and a portion of the first group G1 overlap when projected onto the first surface 10a. The second region R2 and a portion of the second group G2 overlap when projected onto the first surface 10a.
The second substrate unit 20u includes a second substrate 20s and counter electrodes 21. The counter electrodes 21 include a first counter electrode 21a and a second counter electrode 21b.
The second substrate 20s is light-transmissive. The multiple first electrodes 11 are disposed between the first substrate 10s and the second substrate 20s.
The first counter electrode 21a is provided between the first substrate unit 10u and the second substrate 20s. The first region R1 and a portion of the first counter electrode 21a overlap when projected onto the first surface 10a.
The second counter electrode 21b is provided between the first substrate unit 10u and the second substrate 20s. The second region R2 and a portion of the second counter electrode 21b overlap when projected onto the first surface 10a. The second counter electrode 21b is separated from the first counter electrode 21a in a second direction D2. The second direction D2 is parallel to the first surface 10a and intersects the first direction D1.
Thus, the multiple counter electrodes 21 are provided. The multiple counter electrodes 21 are arranged in the second direction D2. Each of the multiple counter electrodes 21 extends along a second orthogonal direction Da2. The second orthogonal direction Da2 is perpendicular to the second direction D2. The second direction D2 may be perpendicular to the first direction D1 or may be tilted with respect to the first direction D1.
The liquid crystal layer 30 is provided between the first substrate unit 10u and the second substrate unit 20u. The liquid crystal layer 30 includes a first liquid crystal region 30a and a second liquid crystal region 30b. The first liquid crystal region 30a and the first region R1 overlap when projected onto the first surface 10a. The second liquid crystal region 30b and the second region R2 overlap when projected onto the first surface 10a.
The liquid crystal layer 30 includes a liquid crystal 31; and the liquid crystal 31 includes, for example, a nematic liquid crystal. For example, the long axis (the director) of the liquid crystal 31 has a component parallel to the first direction D1 when projected onto the first surface 10a. The dielectric anisotropy of the liquid crystal 31 may be positive or negative.
The controller 150 is electrically connected to the multiple first electrodes 11, the first counter electrode 21a, and the second counter electrode 21b.
In the specification of the application, the state of being electrically connected includes the state in which multiple conductors are in direct contact. The state of being electrically connected includes the state in which multiple conductors are connected via another conductor and a current flows between the multiple conductors. The state of being electrically connected includes the state in which it is possible to form a state in which multiple conductors are connected via a switch element (e.g., a transistor, etc.) and a current flows between the multiple conductors.
The first substrate 10s and the second substrate 20s include, for example, a transparent glass substrate or a transparent resin substrate.
The first electrode 11 and the counter electrode 21 include transparent conductive films. These electrodes include oxides including at least one element selected from the group consisting of In, Sn, Zn, and Ti. At least a portion of these electrodes includes, for example, an indium tin oxide (ITO) film. A supplemental interconnect may be provided for each of these electrodes. The supplemental interconnect includes, for example, a metal; and a low resistance is obtained.
As shown in
A tilt angle θ is the angle between the first surface 10a and the long axis of the liquid crystal 31 of the liquid crystal layer 30. In the case where the dielectric anisotropy of the liquid crystal 31 of the liquid crystal layer 30 is positive, the angle (the pretilt angle) between the first surface 10a and the long axis of the liquid crystal 31 for the initial alignment of the liquid crystal layer 30 is small. The pretilt angle is not less than 0 degrees and not more than 30 degrees. The tilt angle θ of the liquid crystal 31 in the region between the first electrodes 11 and the counter electrodes 21 becomes large when an applied voltage (greater than a threshold voltage) is applied between the first electrodes 11 and the counter electrodes 21. The tilt angle θ is substantially maintained at the pretilt angle in the liquid crystal 31 between the counter electrode 21 and the region between the multiple first electrodes 11. A distribution is formed in the alignment of the liquid crystal of the liquid crystal layer 30. In other words, regions where the tilt angle θ is large are formed; and regions where the tilt angle θ is small are formed.
The liquid crystal 31 has birefringence. A refractive index no (the refractive index of ordinary light) in the short-axis direction of the liquid crystal 31 is less than a refractive index ne (the refractive index of extraordinary light) in the long-axis direction of the liquid crystal 31.
The effective refractive index of the liquid crystal layer 30 changes according to the distribution of the tilt angle θ of the liquid crystal of the liquid crystal 31. For example, the effective refractive index n(θ) is expressed by ne·no/(ne2·sin2(θ)+no2·cos2(θ))1/2. The effective refractive index n(θ) changes due to the tilt angle θ changing according to the applied voltage. Because the tilt angle θ when applying the voltage changes along the Z-axis direction of the liquid crystal layer 30, the value of the integration along the Z-axis direction of the formula recited above corresponds to the effective refractive index n.
In the case where the dielectric anisotropy of the liquid crystal 31 of the liquid crystal layer 30 is negative, the pretilt angle is set to be large for the initial alignment of the liquid crystal layer 30. For example, a vertical alignment is applied. The pretilt angle is not less than 60 degrees and not more than 90 degrees. The tilt angle θ of the liquid crystal 31 in the region between the first electrodes 11 and the counter electrodes 21 becomes small when the applied voltage is applied between the first electrodes 11 and the counter electrodes 21. At this time as well, regions where the tilt angle θ is large are formed; and regions where the tilt angle θ is small are formed. Thereby, the effective refractive index of the liquid crystal layer 30 changes.
To simplify the description hereinbelow, the case is described where the dielectric anisotropy of the liquid crystal 31 is positive. The description hereinbelow is applicable in the case where the dielectric anisotropy is negative by reversing the absolute value of the voltage (the potential difference).
As shown in
As shown in
For example, the image light 400L that includes multiple parallax images is emitted from the image display unit 400. In such a case, the refractive index neff is changed as shown in
For example, the image light 400L that does not include parallax is emitted from the image display unit 400. In such a case, the refractive index neff is set to be uniform as shown in
In the image display device 510, an image (a 3D image) that includes multiple parallax images is displayed in a portion (a 3D region) of the screen 400d; and an image (a 2D image) that does not include parallax is displayed in one other portion (a 2D region) of the screen 400d. To correspond to these regions in the liquid crystal optical device 110, a region where a GRIN lens is formed and a region where a GRIN lens substantially is not formed are provided.
At least a portion of the region where the GRIN lens is formed corresponds to the first region R1. At least a portion of the region where the change of the refractive index neff is small (the region where the GRIN lens substantially is not formed) corresponds to the second region R2.
As shown in
The region 201a where the first group G1 and the first counter electrode 21a overlap corresponds to the region where the 3D image is displayed. The region 201d where the second group G2 and the second counter electrode 21b overlap corresponds to the region where the 2D image is displayed. A region 201b where the first group G1 and the second counter electrode 21b overlap corresponds to the region where the 2D image is displayed. A region 201c where the second group G2 and the first counter electrode 21a overlap corresponds to the region where the 2D image is displayed.
In the region 201a as shown in
In the region 201b as shown in
In the region 201c as shown in
In the region 201d as shown in
Thus, the region is formed where the GRIN lens corresponding to the 3D image is formed; and the region is formed where the change of the refractive index neff is small to correspond to the 2D image.
Crosstalk occurs in the region where the first group G1, the second group G2, the first counter electrode 21a, and the second counter electrode 21b are formed. The crosstalk and the difference Δneff between the maximum value and minimum value of the refractive index neff change due to the voltage supplied to these electrodes.
An example of characteristics of the liquid crystal layer 30 when the high voltage Veh, the low voltage Vel, the high common voltage Vch, and the low common voltage Vcl are changed will now be described.
In a first condition Cv1 as shown in
In a second condition Cv2, the high voltage Veh is set to the second electrode high potential Veh2. The low voltage Vel is set to the second electrode low potential Vel2. The second electrode high potential Veh2 is lower than the first electrode high potential Veh1. The high common voltage Vch is set to the second counter high potential Vch2. The second counter high potential Vch2 is, for example, (Veh2+Vel2)/2. The low common voltage Vcl is set to the second counter low potential Vcl2 (e.g., 0 V). A difference ΔVe2 between the second electrode high potential Veh2 and the second electrode low potential Vel2 is small. The difference ΔVe2 is smaller than the difference ΔVe1.
In a third condition Cv3, the high voltage Veh is set to the third electrode high potential Veh3. The low voltage Vel is set to the third electrode low potential Vel3. The third electrode high potential Veh3 is between the first electrode high potential Veh1 and the second electrode high potential Veh2. The high common voltage Vch is set to the third counter high potential Vch3. The third counter high potential Vch3 is, for example, (Veh3+Vel3)/2. The low common voltage Vcl is set to the third counter low potential Vcl3 (e.g., 0 V). A difference ΔVe3 between the third electrode high potential Veh3 and the third electrode low potential Vel3 is medium. The difference ΔVe3 is between the difference ΔVe1 and the difference ΔVe2.
For example, Veh1−Vel1≧Veh3−Vel3≧Veh2−Vel2.
For the first condition Cv1 as shown in
For the second condition Cv2 as shown in
For the third condition Cv3 as shown in
The characteristics of the region 201c and the region 201d are similar to the characteristics of the region 201b.
In the region 201a as shown in
On the other hand, the differences Δneff1b, Δneff2b, and Δneff3b between the maximum value and minimum value of the refractive index neff of the refractive index distributions (a first small refractive index distribution neff1b, a second small refractive index distribution neff2b, and a third small refractive index distribution neff3b) are small in the regions 201b, 201c, and 201d for the first condition Cv1, the second condition Cv2, and the third condition Cv3. For the first condition Cv1, the change of the refractive index neff in the lens edge region is large; and the display of the 2D image is thereby difficult to view. For the second condition Cv2, the change of the refractive index neff in the lens edge region is small; and the display of the 2D image is thereby easy to view. For the third condition Cv3, the characteristics are medium between the first condition Cv1 and the second condition Cv2. For example, the first small refractive index distribution may be called a second lens for convenience. However, the refractive index of the first small refractive index distribution may be substantially constant. For example, the second small refractive index distribution may be called a fourth lens for convenience. However, the refractive index of the second small refractive index distribution may be substantially constant. For example, the third small refractive index distribution may be called a sixth lens for convenience. However, the refractive index of the third small refractive index distribution may be substantially constant.
The first condition Cv1 is a 3D preferential condition. The second condition Cv2 is a 2D preferential condition. The third condition Cv3 is a medium condition.
In the embodiment, the first condition Cv1 and the second condition Cv2 recited above are used by switching between the conditions based on the image information Id and the control signal Sc (e.g., the input signal from the viewer, etc.) that is acquired. The third condition Cv3 also may be used by switching to the third condition Cv3.
In other words, the controller 150 implements the selecting operation based on at least one of the image information Id or the control signal Sc that is acquired. The selecting operation includes selectively implementing one of a first operation (a first mode) or a second operation (a second mode) recited below.
The first operation includes forming the refractive index distribution (the first large refractive index distribution neff1a) in the region 201a (the first liquid crystal region 30a) and forming the refractive index distribution (the first small refractive index distribution neff1b) in the region 201c (the second liquid crystal region 30b). The difference Δneff1a between the maximum value and minimum value of the refractive index of the first liquid crystal region 30a of the first large refractive index distribution neff1a is larger than the difference Δneff1b between the maximum value and minimum value of the refractive index of the second liquid crystal region 30b of the first small refractive index distribution neff1b. The refractive index neff of the first small refractive index distribution neff1b substantially may not change.
The first large refractive index distribution neff1a is formed by forming a potential difference having a first absolute value between the first group G1 and the first counter electrode 21a.
The first small refractive index distribution neff1b is formed by forming a potential difference having a second absolute value between the second group G2 and the second counter electrode 21b. The second absolute value is different from the first absolute value.
For example, the first operation includes setting the first group G1 to the first electrode high potential Veh1, setting the first counter electrode 21a to the first counter low potential Vc11, setting the second group G2 to the first electrode low potential Vel1, and setting the second counter electrode 21 to the first counter high potential Vch1. By setting these potentials, the potential difference having the first absolute value and the potential difference having the second absolute value recited above are formed; and the refractive index distribution recited above is formed.
The second operation includes forming the refractive index distribution (the second large refractive index distribution neff2a) in the region 201a (the first liquid crystal region 30a) and forming the refractive index distribution (the second small refractive index distribution neff2b) in the region 201c (the second liquid crystal region 30b). The difference Δneff2a between the maximum value and minimum value of the refractive index of the first liquid crystal region 30a of the second large refractive index distribution neff2a is larger than the difference Δneff2b between the maximum value and minimum value of the refractive index of the second liquid crystal region 30b of the second small refractive index distribution neff2b. The refractive index neff of the second small refractive index distribution neff2b substantially may not change.
The second large refractive index distribution neff2a is formed by forming a potential difference having a third absolute value between the first group G1 and the first counter electrode 21a.
The second small refractive index distribution neff2b is formed by forming a potential difference having a fourth absolute value between the second group G2 and the second counter electrode 21b. The fourth absolute value is different from the third absolute value.
For example, the second operation includes setting the first group G1 to the second electrode high potential Veh2, setting the first counter electrode 21a to the second counter low potential Vcl2, setting the second group G2 to the second electrode low potential Vel2, and setting the second counter electrode 21b to the second counter high potential Vch2. By setting these potentials, the potential difference having the third absolute value and the potential difference having the fourth absolute value recited above are formed; and the refractive index distribution recited above is formed.
The difference Δneff1a between the maximum value and minimum value of the refractive index of the first liquid crystal region 30a of the first large refractive index distribution neff1a is larger than the difference Δneff2a between the maximum value and minimum value of the refractive index of the first liquid crystal region 30a of the second large refractive index distribution neff2a.
The first operation uses the first condition Cv1. The second operation uses the second condition Cv2. The first operation uses the 3D preferential condition. The second operation uses the 2D preferential condition.
In the embodiment, one of the first operation or the second operation is selectively implemented based on the image information Id and the control signal Sc (e.g., the input signal from the viewer or the like) that is acquired. For example, the 3D preferential operation is implemented in the case where attention is being given to the content of the image information Id on the 3D display. For example, the 2D preferential operation is implemented in the case where attention is being given to the content of the image information Id on the 2D display.
According to the embodiment, the operation is switched between an operation suited to the 3D display and an operation suited to the 2D display. Thereby, a liquid crystal optical device having good optical characteristics and an image display device having high display quality can be provided.
In the embodiment, the controller 150 may further implement a third operation (a third mode). For example, the third operation uses the third condition Cv3.
The third operation includes forming the third large refractive index distribution neff3a in the first liquid crystal region 30a and forming the third small refractive index distribution neff3b in the second liquid crystal region 30b. The difference Δneff3a between the maximum value and minimum value of the refractive index of the first liquid crystal region 30a of the third large refractive index distribution neff3a is larger than the difference Δneff3b between the maximum value and minimum value of the refractive index of the second liquid crystal region 30b of the third small refractive index distribution neff3b.
The third large refractive index distribution neff3a is formed by forming a potential difference having a fifth absolute value between the first group G1 and the first counter electrode 21a.
The third small refractive index distribution neff3b is formed by forming a potential difference having a sixth absolute value between the second group G2 and the second counter electrode 21b. The sixth absolute value is different from the fifth absolute value. The fifth absolute value is between the first absolute value and the third absolute value.
For example, the third operation includes setting the first group G1 to the third electrode high potential Veh3, setting the first counter electrode 21a to the third counter low potential Vcl3, setting the second group G2 to the third electrode low potential Vel3, and setting the second counter electrode 21b to the third counter high potential Vch3.
For example, the case where the dielectric anisotropy of the liquid crystal 31 included in the liquid crystal layer 30 is positive is as follows. The first absolute value is greater than the second absolute value. The third absolute value is greater than the fourth absolute value. The first absolute value is greater than the third absolute value.
For example, the case where the dielectric anisotropy of the liquid crystal 31 included in the liquid crystal layer 30 is negative is as follows. The first absolute value is less than the second absolute value. The third absolute value is less than the fourth absolute value. The first absolute value is less than the third absolute value.
Examples of the first operation, the second operation, and the third operation of the liquid crystal optical device 110 will now be described.
As shown in
The first region R1 and at least a portion of the first display region Q1 overlap when projected onto the first surface 10a. The second region R2 and at least a portion of the second display region Q2 overlap when projected onto the first surface 10a.
The screen 400d has first to fourth sides si to s4. The second side s2 is separated from the first side s1. The third side s3 intersects the first side s1 and the second side s2. The fourth side s4 is separated from the third side s3 and intersects the first side si and the second side s2.
In the examples of
In the examples of
In the examples of
In the examples of
In the examples of
For example, a threshold (a first surface area threshold) is determined for the proportion of the surface area. The controller 150 implements the first operation when the ratio of the first surface area of the first display region Q1 to the second surface area of the second display region Q2 is greater than the first surface area threshold. The controller 150 implements the second operation when the ratio is not more than the first surface area threshold.
The third operation may be implemented as necessary. In such a case, for example, a second surface area threshold is determined for the proportion of the surface area. The second surface area threshold is less than the first surface area threshold. The controller 150 implements the first operation when the ratio of the first surface area of the first display region Q1 to the second surface area of the second display region Q2 is greater than the first surface area threshold. The controller implements the third operation when the ratio is not more than the first surface area threshold and greater than the second surface area threshold. The controller 150 implements the second operation when the ratio is not more than the second surface area threshold.
Thus, the controller 150 implements the operation by switching the operation according to the surface area of the 3D image and the surface area of the 2D image.
In such cases as well, the first display region Q1 and the second display region Q2 are provided in the screen 400d of the image display unit 400.
In the examples of
In the examples of
In the examples of
In the examples of
In the examples of
In such cases as well, for example, the controller 150 implements one of the first operation or the second operation by switching between the operations by using the first surface area threshold recited above. The third operation may be further implemented by using the second surface area threshold.
In the example of
On the other hand, in the example of
Thus, the controller 150 implements the first operation when the first display region Q1 and a center 400c of the screen 400d overlap. The controller 150 implements the second operation when the second display region Q2 and the center 400c of the screen 400d overlap. Thus, the operation may be switched based on the position inside the screen 400d of the 3D image and the position inside the screen 400d of the 2D image.
In these examples, the display content is displayed in a window configuration.
In the example of
On the other hand, in the example of
Thus, the controller 150 implements the first operation when a first content Qc1 displayed in the first display region Q1 is disposed on a second content Qc2 displayed in the second display region Q2. The controller 150 implements the second operation when the second content Qc2 is disposed on the first content Qc1. Thus, the operation may be switched based on the relative disposition (the vertical relationship) between the window of the 3D image and the window of the 2D image.
For example, the control signal Sc (an operation signal) is supplied from the user (the viewer) in these examples. For example, the control signal Sc is a signal from the operation of an input device (a mouse, a keyboard, a touch panel, etc.). An arrow 400a that is operated by the user is displayed in the screen 400d in the examples of these figures.
In the example of
In the example of
Thus, the controller 150 may selectively implement one of the first operation or the second operation based on the control signal Sc.
The control signal Sc may include information relating to the direction of the line of sight of the user (the viewer). For example, an imaging unit that images an image of the viewer is provided. The position inside the screen 400d given attention by the viewer can be estimated using the image of the viewer.
The first operation is implemented when the position that is given attention corresponds to the 3D image. The second operation is implemented when the position that is given attention corresponds to the 2D image.
Thus, the control signal Sc may include information relating to the line-of-sight direction of the viewer. In such a case, the controller 150 may selectively implement one of the first operation or the second operation based on the line-of-sight direction.
The operation may be selected based on two or more of the surface areas of the 3D image and the 2D image, the positions inside the screen 400d of the 3D image and the 2D image, or the vertical (frontward/rearward) arrangement of the content (the windows). In such a case, an evaluation value (a weight coefficient) may be calculated; and one of the first operation or the second operation may be implemented based on the evaluation value.
For example, the controller 150 may calculate the evaluation value according to at least one of the amount of character information included in the image information Id or the amount of three-dimensional display information included in the image information. The controller 150 may selectively implement one of the first operation or the second operation based on the evaluation value.
Thus, a configuration is used in which the mode of the voltage is selected according to whether the window selected by the user using an input I/F such as a mouse, etc., is the 3D display or the 2D display. However, even in the case where the window selected by the user is the 3D display, for example, it is favorable to execute the second operation or the third operation rather than the first operation if the size of the selection, e.g., the 3D window, is small. In such a case, the determination is performed using the weighting.
For example, the evaluation value E recited below is used.
E=D(window size)×α
The evaluation value E is determined using functions that provide a maximum value of 1. D(window size) is a function that decreases as the selected window becomes smaller. α is a function that is assigned the value of α1 when the 3D display is selected and is assigned the value of α2 when the 2D display is selected, where α2 is smaller than α1.
For example, a first threshold Th1 and a second threshold Th2 are predetermined.
The first operation (the 3D preferential operation) is performed when E>Th1.
The third operation (balanced) is performed when Th1≧W>Th2.
The second operation (the 2D preferential operation) is performed when Th2≧E.
As an example, the weight of the 3D display mode is set to 0.75 and the weight of the 2D display mode is set to 0.25 when the user performs the mode selection using a mouse on the screen. As an example, the surface area of the 3D display window is 20% of the entire surface area; and the surface area of the 2D display window is 80% of the entire surface area. In such a case, the evaluation value of the 3D display mode is (0.75+0.2)/2=0.45, and the evaluation value of the 2D display mode is (0.25+0.8)/2=0.55.
For example, 0.33 and 0.66 are set as the criteria for the evaluation value. Namely,
3D display mode: 0.66<E≦1
2D/3D balanced display mode: 0.33<E≦0.66
2D display mode: 0<E≦0.33.
Using these conditions, the 2D/3D balanced display mode is selected for the example recited above.
Although the evaluation value relating to the surface area of the window is calculated in the example recited above, an evaluation value relating to the position in the screen of the window may be calculated. Thus, the controller 150 may calculate a first evaluation values corresponding to the parameters including the surface area and position of the 3D region and a second evaluation value corresponding to the weight of the first mode and the weight of the second mode; and the controller 150 may select the multiple display modes according to the comparison result between the first and second evaluation values and predetermined thresholds.
For example, for a naked-eye 2D/3D switching display that partially switches between the 2D display and the 3D display, the embodiment may include a unit that calculates the weights of the 3D display and the 2D display according to the state of the 3D display content and may include a unit that determines, using the calculated values, a first voltage distribution to be applied in the 3D display unit region of a light ray control element provided on the display and a second voltage distribution to be applied in the 2D display unit region of the light ray control element and applies voltages corresponding to the first voltage distribution and the second voltage distribution in the 2D display unit region and the 3D display unit region.
In the embodiment, the selection of the first operation and the second operation may not be performed. Such an example will now be described.
In the example of
In the example of
In the example of
In the example of
For example, the controller 150 implements the first operation when the first display region Q1 contacts the first side Si and the second side s2 or when the second display region Q2 contacts the first side s1 and the second side s2. For example, the controller 150 implements the first operation when the first display region Q1 contacts the third side s3 and the fourth side s4 or when the second display region Q2 contacts the third side s3 and the fourth side s4.
In a liquid crystal optical device 111 (an image display device 511) as shown in
The multiple second electrodes 12 are provided between the first substrate 10s and the liquid crystal layer 30. The multiple second electrodes 12 are disposed respectively between the multiple first electrodes 11.
For example, in the first operation, the controller 150 sets the absolute value of the potential difference between the first counter electrode 21a and at least one of the multiple second electrodes 12 (the absolute value of the potential difference of the second electrodes 12) to be small. For example, the absolute value is set to 0 V.
The positions that correspond to the first electrodes 11 correspond to, for example, the lens edges. The region between the multiple first electrodes 11 corresponds to, for example, the lens center. The second electrode 12 is provided at the position corresponding to the lens center; and the potential difference that is applied to the liquid crystal layer at this position is small compared to at the lens edges. Thereby, it is easy to control the characteristics of the refractive index distribution that is formed.
The controller 150 may set the absolute value of the potential difference of the second electrode 12 to be smaller than the first absolute value (the absolute value of the potential difference between the first counter electrode 21a and the multiple first electrodes 11).
An image display device according to the embodiment includes the image display unit 400 and at least one of the liquid crystal optical device 110 or 111, or liquid crystal optical devices of modifications of the liquid crystal optical device 110 or 111. As the liquid crystal optical devices of the modifications, it is sufficient to use a configuration in which the refractive index distribution inside the liquid crystal layer is controlled by the applied voltage. The embodiment is realizable regardless of the electrode configuration and the applied voltage of the liquid crystal optical device 110 and the liquid crystal optical device 111. According to the embodiment, an image display device having high display quality can be provided by using a liquid crystal optical device having good optical characteristics.
The embodiment relates to a control device that controls the liquid crystal optical device. The liquid crystal optical device includes the liquid crystal optical device and modifications of the liquid crystal optical device according to the first embodiment. The liquid crystal optical device includes the optical unit 105 recited above. The control device according to the embodiment corresponds to the controller 150 recited above.
The optical unit 105 includes the first substrate unit 10u, the second substrate unit 20u, and the liquid crystal layer 30. The control device is electrically connected to the multiple first electrodes 11 of the first substrate unit 10u, the first counter electrode 21a of the second substrate unit 20u, and the second counter electrode 21b.
The control device implements a selecting operation including selectively implementing one of the first operation or the second operation recited above based on at least one of the control signal Sc that is acquired or the image information Id input to the image display unit 400 that is stacked with the optical unit 105 and emits the image light.
According to the embodiment, a control device of a liquid crystal optical device having good optical characteristics can be provided.
According to the embodiments, a liquid crystal optical device having good optical characteristics, a control device of the liquid crystal optical device, and an image display device can be provided.
In the specification of the application, “perpendicular” and “parallel” refer to not only strictly perpendicular and strictly parallel but also include, for example, the fluctuation due to manufacturing processes, etc. It is sufficient to be substantially perpendicular and substantially parallel.
Hereinabove, exemplary embodiments of the invention are described with reference to specific examples. However, the embodiments of the invention are not limited to these specific examples. For example, one skilled in the art may similarly practice the invention by appropriately selecting specific configurations of components included in liquid crystal optical devices and imaging devices such as optical units, substrate units, substrates, electrodes, liquid crystal layers, controllers, image display units, etc., from known art. Such practice is included in the scope of the invention to the extent that similar effects thereto are obtained.
Further, any two or more components of the specific examples may be combined within the extent of technical feasibility and are included in the scope of the invention to the extent that the purport of the invention is included.
Moreover, all liquid crystal optical devices, control devices of the liquid crystal optical devices, and image display devices practicable by an appropriate design modification by one skilled in the art based on the liquid crystal optical devices, control devices of the liquid crystal optical devices, and image display devices described above as embodiments of the invention also are within the scope of the invention to the extent that the spirit of the invention is included.
Various other variations and modifications can be conceived by those skilled in the art within the spirit of the invention, and it is understood that such variations and modifications are also encompassed within the scope of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-186468 | Sep 2014 | JP | national |
