Optical path control member and display device including the same

Abstract

The optical path control member according to the embodiment includes a first substrate, a first electrode disposed on the first substrate, a second substrate disposed on the first substrate, a second electrode disposed under the second substrate, and an optical conversion unit disposed between the first electrode and the second electrode, wherein the optical conversion unit includes a partition portion and a accommodating portion, and the accommodating portion includes a dispersion liquid and optical conversion particles dispersed in the dispersion liquid, and the accommodating portion is driven to a public mode or a privacy mode depending on whether or not a voltage is applied, the public mode includes a step of applying an initial positive voltage and a step of applying a maintenance positive voltage, and the privacy mode includes a step of applying a negative voltage, and the steps of applying the initial positive voltage, the step of applying the maintenance positive voltage, and the step of applying the negative voltage are performed sequentially, and the magnitude of the initial positive voltage is greater than the magnitude of the maintenance positive voltage.

Description

[Technical field]

[0001] The embodiments relate to an optical path control member and a display device including the same. [Background technology]

[0002] Light-shielding films block the transmission of light from a light source and are attached to the front of display panels, which are display devices used in mobile phones, notebook PCs, tablet PCs, vehicle navigation systems, vehicle touch screens, etc. When the display emits light from the screen, they adjust the viewing angle of light according to the angle of incidence of the light, allowing users to see clear image quality at the viewing angle they require.

[0003] In addition, the light-shielding film can be used on the windows of vehicles and buildings to block a portion of external light to prevent glare or to prevent the inside from being seen from the outside.

[0004] That is, the light-shielding film can be a light-path control member that controls the path of light movement, blocking light in a specific direction and transmitting light in a specific direction. This allows the light-shielding film to control the light transmission angle, thereby controlling the user's viewing angle.

[0005] Meanwhile, such light-blocking films can be divided into light-blocking films that can always control the viewing angle regardless of the surrounding environment or the user's environment, and switchable light-blocking films that allow the user to turn on and off the viewing angle control depending on the surrounding environment or the user's environment.

[0006] Such a switchable light-blocking film can be realized by filling the inside of a receiving portion with a light-converting material including particles that can move when a voltage is applied and a dispersion liquid that disperses the particles, and by dispersing and agglomerating the particles, the receiving portion of the light-converting portion is converted into a light-transmitting portion and a light-blocking portion.

[0007] For example, a positive voltage can be applied to negatively charged particles to move the particles toward the electrode, thereby operating the container as a light-transmitting section, and when converting it into a light-blocking section, a negative voltage can be applied to redisperse the particles within the dispersion liquid.

[0008] In this case, when the magnitude of the positive voltage is increased, the movement speed of the light conversion particles increases, but the stress applied to the light conversion particles causes the light conversion particles to clump together and increase in particle size, which causes a problem in that the light transmittance decreases when the light conversion particles are operated as a light transmission section.

[0009] In addition, when the magnitude of the positive voltage is reduced, the moving speed of the light converting particles is reduced, and the driving speed is reduced, so that there is a problem in that the light transmittance is reduced when the light transmitting portion is driven.

[0010] Therefore, there is a need for an optical path control member with a new structure that can solve the above problems. Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the embodiment is to provide an optical path control component having improved reliability and driving characteristics. [Means for solving the problem]

[0012] An optical path control member according to an embodiment includes a first substrate, a first electrode disposed on the first substrate, a second substrate disposed on the first substrate, a second electrode disposed under the second substrate, and an optical conversion unit disposed between the first electrode and the second electrode, the optical conversion unit including a partition portion and a accommodating portion, the accommodating portion including a dispersion liquid and optical conversion particles dispersed in the dispersion liquid, the accommodating portion being driven to a public mode or a privacy mode depending on whether or not a voltage is applied, the public mode including a step of applying an initial positive voltage and a step of applying a maintenance positive voltage, the privacy mode including a step of applying a negative voltage, the step of applying the initial positive voltage, the step of applying the maintenance positive voltage, and the step of applying the negative voltage being performed in sequence, and the magnitude of the initial positive voltage being greater than the magnitude of the maintenance positive voltage. Effect of the Invention

[0013] The light path control member according to the embodiment may include applying voltages of different magnitudes when driving the open mode by applying voltages.

[0014] In particular, the method can include the steps of applying an initial voltage and applying a sustain voltage.

[0015] That is, the light path control member according to the embodiment may first apply an initial voltage greater than the sustain voltage magnitude, quickly drive at a transmittance adjacent to the target transmittance, and then reduce the voltage to a relatively low sustain voltage to drive the open mode at the target transmittance.

[0016] As a result, the open mode is driven with a low sustain voltage, so that the stress on the light conversion particles caused by a high voltage can be alleviated, and the clumping phenomenon of the light conversion particles can be minimized.

[0017] This allows the display device to be driven in the public mode with a uniform transmittance for a long period of time without any decrease in the transmittance in the public mode.

[0018] Also, by rapidly changing the transmittance depending on the initial voltage, the drawback of delayed driving time due to low voltage can be compensated for.

[0019] In other words, the optical path control member of the embodiment can reduce the driving time by using a high initial voltage, while preventing the agglomeration of optical conversion particles by using a low maintenance voltage, thereby improving the driving characteristics, driving speed, and reliability of the optical path control member.

[0020] Furthermore, the light path control member according to the embodiment may include a step of applying a quiescent voltage of 0V for a certain period of time during conversion from the privacy mode to the public mode.

[0021] This includes a step of relieving stress on the light conversion particles accumulated in the public mode and the privacy mode, so that clumping of the light conversion particles can be prevented.

[0022] As a result, the light transmittance can be prevented from decreasing even when the public mode and the privacy mode are repeatedly operated, and the life of the light path control member can be improved. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of an optical path control member according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line AA′ in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along the line AA′ in FIG. [Figure 4] 11A and 11B are diagrams for explaining a method of driving the light path control member according to the embodiment based on the voltage magnitude. [Diagram 5] 11 is a diagram for explaining the light transmittance depending on the voltage magnitude of the light path control member according to the embodiment. FIG. [Figure 6] 11 is a diagram for explaining the light transmittance depending on the voltage magnitude of the light path control member according to the embodiment. FIG. [Figure 7]1 is a diagram illustrating a change in light transmittance of an optical path control member according to an example and a comparative example. [Figure 8] 1 is a diagram illustrating a change in light transmittance of an optical path control member according to an example and a comparative example. [Figure 9] 1 is a diagram illustrating a change in light transmittance of an optical path control member according to an example and a comparative example. [Figure 10] 11A and 11B are diagrams for explaining changes in light transmittance depending on the presence or absence of a rest voltage of the light path control members according to the examples and the comparative examples. [Figure 11] 11A and 11B are diagrams for explaining changes in light transmittance depending on the presence or absence of a rest voltage of the light path control members according to the examples and the comparative examples. [Figure 12] FIG. 1 is a cross-sectional view of a display device to which a light path control member according to an embodiment is applied. [Figure 13] FIG. 1 is a cross-sectional view of a display device to which a light path control member according to an embodiment is applied. [Figure 14] 1 is a diagram for explaining an embodiment of a display device to which a light path control member according to an embodiment is applied; [Figure 15] 1 is a diagram for explaining an embodiment of a display device to which a light path control member according to an embodiment is applied; [Figure 16] 1A and 1B are diagrams for explaining an embodiment of a display device to which a light path control member according to an embodiment is applied; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical concept of the present invention is not limited to some of the embodiments described, and may be realized in various different forms, and one or more of the components of the embodiments may be selectively combined or substituted within the scope of the technical concept of the present invention.

[0025] Furthermore, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted in a manner that is commonly understood by a person having ordinary knowledge in the technical field to which the present invention belongs, unless otherwise clearly defined and described, and commonly used terms, such as terms defined in a dictionary, may be interpreted in light of the contextual meaning of the relevant art.

[0026] In addition, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the singular form can include the plural form unless otherwise specified in the text, and when it is described as "A and (and) at least one (or more) of B and C", it can include one or more of all combinations that can be combined with A, B, and C.

[0027] In addition, in describing components of the present invention, terms such as 1, 2, A, B, (a), (b), etc. are used. These terms are merely used to distinguish the components from other components, and do not limit the nature, order, or sequence of the components.

[0028] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it includes not only cases where the component is directly coupled, coupled, or connected to the other component, but also cases where the component is "coupled," "coupled," or "connected" by another component between the component and the other component.

[0029] In addition, when described as being formed or disposed "on or under" each component, "on or under" includes not only the case where the two components are in direct contact with each other, but also the case where one or more other components are formed or disposed between the two components.

[0030] In addition, when it is expressed as "above" or "below," it can include the meaning of not only the upward direction but also the downward direction based on one component.

[0031] Hereinafter, optical path control members according to embodiments will be described with reference to the drawings.

[0032] FIG. 1 is a perspective view of an optical path controlling member according to an embodiment.

[0033] 1 and 2, the light path control member according to the embodiment may include a first substrate 110, a second substrate 120, a first electrode 210, a second electrode 220, and a light conversion part 300. In the embodiment, as shown in FIG.

[0034] The light conversion unit 300 may be disposed between the first substrate 110 and the second substrate 120. In particular, the light conversion unit 300 may be disposed between the first electrode 210 and the second electrode 220.

[0035] An adhesive layer 410 may be disposed between the light conversion unit 300 and the first electrode 210. For example, a transparent adhesive layer 410 capable of transmitting light may be disposed between the light conversion unit 300 and the first electrode 210. For example, the adhesive layer 410 may include an optically transparent adhesive (OCA).

[0036] In addition, a buffer layer 420 may be disposed between the light conversion part 300 and the second electrode 220. This may improve the adhesive strength between the light conversion part 300 and the first electrode 210, which include different materials.

[0037] The light conversion part 300 and the second electrode 220 may be bonded to each other via the buffer layer 420 .

[0038] 2 and 3 are cross-sectional views taken along the line AA' of FIG.

[0039] 2 and 3, the light conversion part 300 may include a partition part 310, a receiving part 320, and a base part 350.

[0040] The partition parts 310 and the accommodating parts 320 may be included in a plurality of pieces, and the partition parts 310 and the accommodating parts 320 may be arranged alternately. That is, one accommodating part 320 may be arranged between two adjacent partition parts 310, and one partition part 310 may be arranged between two adjacent accommodating parts 320.

[0041] The base 350 may be disposed on the receiving portion 320. In particular, the base 350 may be disposed between the receiving portion 320 and the buffer layer 420. Thus, the light conversion portion 300 may be bonded to the second electrode 220 via the base 350 and the buffer layer 420.

[0042] The base portion 350 is a region formed during an imprint process for forming the partition portion 310 and the receiving portion 320, and may include the same material as the partition portion 310.

[0043] The partition 310 can transmit light, and the receiving part 320 can change its light transmittance according to the application of a voltage.

[0044] In detail, a light conversion material 330 may be disposed in the receiving part 320. The light transmittance of the receiving part 320 may be changed by the light conversion material 330. The light conversion material 330 may include light conversion particles 330b that are moved by application of a voltage and a dispersion liquid 330a that disperses the light conversion particles 330b. In addition, the light conversion material 330 may further include a dispersant that prevents the light conversion particles 330a from agglomerating.

[0045] The input of the voltage may move the light conversion particles 330b inside the dispersion liquid 330a. For example, referring to FIG. 2, the light conversion particles 330b inside the dispersion liquid 330a may have negatively charged surfaces, and when a positive voltage is applied through the first electrode 210 and the second electrode 220, the light conversion particles 330b may move toward the first electrode 210 or the second electrode 220, and the receiving portion 320 may become a light transmitting portion.

[0046] 3, when a negative voltage is applied across the first electrode 210 and the second electrode 220, the light conversion particles 330b are dispersed again within the dispersion liquid 330a, and the receiving part 320 may become a light blocking part.

[0047] On the other hand, when the magnitude of the positive voltage is increased, the movement speed of the light converting particles 330b increases, but the stress applied to the light converting particles 330b causes the light converting particles 330b to clump together and increase in particle size. As a result, when the light converting particles 330b are operated as a light transmitting portion, the light transmittance of the light path control member decreases.

[0048] In addition, when the magnitude of the positive voltage is reduced, the moving speed of the light converting particles decreases, causing a decrease in the driving speed, which results in a decrease in the light transmittance of the light path control member when it is driven as a light transmitting portion.

[0049] Therefore, the light path control material according to the embodiment controls the driving method of the voltage applied to the receiving part to prevent the clumping phenomenon of the light conversion particles and improve the driving speed.

[0050] 4, the light path control member according to the embodiment may be driven in an initial mode, a public mode, and a privacy mode in this order. The initial mode, the public mode, and the privacy mode may be sequentially performed. That is, the public mode and the privacy mode may be sequentially performed in one cycle, and the cycle may be repeated depending on the user's usage environment.

[0051] The initial mode is a state in which the light path control member is initially turned on and the light conversion particles 330b are dispersed in the dispersion liquid 330a, and the state of the light conversion particles in the initial mode may be the same as the state of the light conversion particles in the privacy mode. The public mode is a state in which the light conversion particles 330b are moved toward the first electrode 210 or the second electrode 220, and the privacy mode is a state in which the light conversion particles 330b are dispersed in the dispersion liquid 330a.

[0052] In the initial mode, no voltage may be applied. That is, in the initial mode, no voltage is applied from the first electrode 210 and the second electrode 220. Thus, the light conversion particles 330b may be dispersed and disposed inside the dispersion liquid 330a. Therefore, in the initial mode, the container may be driven as a light blocking part. That is, the initial mode may correspond to the privacy mode.

[0053] That is, the initial mode may be a mode before the light path control member is driven.

[0054] In the public mode, a voltage may be applied. In particular, a positive voltage or a negative voltage may be applied in the public mode. When a positive voltage is applied in the public mode, a negative voltage may be applied in the privacy mode, and when a negative voltage is applied in the public mode, a positive voltage may be applied in the privacy mode. That is, the public mode and the privacy mode may apply opposite voltages.

[0055] For convenience of explanation, the following description will be focused on the case where a positive voltage is applied in the public mode.

[0056] That is, in the public mode, a positive voltage is applied from the first electrode 210 and the second electrode 220. Thus, the light conversion particles 330b may move toward the first electrode 210 or the second electrode 220. Therefore, in the public mode, the receiving part may be operated as a light transmitting part.

[0057] The reveal mode may include applying an initial positive voltage and applying a sustain positive voltage. In particular, in the reveal mode, the initial positive voltage may be applied first, and then the sustain positive voltage may be applied.

[0058] In the step of applying the initial positive voltage, a relatively large voltage may be applied to reduce the driving time of the optical path control member, and in the step of applying the maintenance positive voltage, a relatively small voltage may be applied to reduce the reliability and power consumption of the optical path control member.

[0059] In detail, the magnitude of the initial positive voltage may be greater than the magnitude of the sustain positive voltage. Thus, the maximum light transmittance at the magnitude of the initial positive voltage and the maximum light transmittance at the magnitude of the sustain positive voltage may be different from each other. That is, the maximum light transmittance at the magnitude of the initial positive voltage may be greater than the maximum light transmittance at the magnitude of the sustain positive voltage.

[0060] Here, the maximum light transmittance can be defined as the maximum light transmittance when the change in light transmittance for 1 minute after application of a positive voltage is 1% or less.

[0061] In the step of applying the initial positive voltage, the initial positive voltage may be applied for a time period during which the light transmittance reaches a value close to the maximum light transmittance when the initial positive voltage and the sustain positive voltage are applied, i.e., the application time of the initial positive voltage may be defined as a time period during which the light transmittance due to the initial positive voltage reaches a value close to the maximum light transmittance of the sustain positive voltage.

[0062] Therefore, the light transmittance achieved depending on the application time of the initial positive voltage may be the same as or different from the maximum light transmittance when the positive sustain voltage is applied, i.e., the light transmittance achieved depending on the application time of the initial positive voltage may be the same as, larger than, or smaller than the maximum light transmittance when the positive sustain voltage is applied.

[0063] In detail, the application time of the initial positive voltage may be defined as the time until the light transmittance due to the initial positive voltage becomes 70% to 130% of the maximum light transmittance of the sustain positive voltage. More specifically, the application time of the initial positive voltage may be defined as the time until the light transmittance due to the initial positive voltage becomes 80% to 120% of the maximum light transmittance of the sustain positive voltage. More specifically, the application time of the initial positive voltage may be defined as the time until the light transmittance due to the initial positive voltage becomes 90% to 110% of the maximum light transmittance of the sustain positive voltage.

[0064] If the application time of the initial positive voltage is set to a time during which the light transmittance due to the initial positive voltage becomes 70% or less of the maximum light transmittance of the positive sustain voltage, when the positive sustain voltage is subsequently applied, the time it takes to reach the maximum light transmittance of the positive sustain voltage becomes longer. As a result, the time it takes for the light transmittance to change becomes longer, which may reduce user visibility and may reduce the driving speed of the light path control member.

[0065] In addition, if the application time of the initial positive voltage is such that the light transmittance due to the initial positive voltage exceeds 130% of the maximum light transmittance of the positive sustain voltage, when the positive sustain voltage is subsequently applied, it takes a longer time for the light transmittance to decrease to the maximum light transmittance of the positive sustain voltage. As a result, the time required for the light transmittance to change becomes longer, which may reduce user visibility and may reduce the driving speed of the light path control member.

[0066] Therefore, the optical path control member of the embodiment can reduce the time required to reach the maximum light transmittance of the positive sustain voltage in the step of applying the positive sustain voltage by applying the initial positive voltage, which is greater than the magnitude of the positive sustain voltage, until the transmittance reaches a value close to the maximum light transmittance of the positive sustain voltage.

[0067] As a result, the light path control member according to the embodiment can have a fast driving time even when a low sustain positive voltage is applied.

[0068] Then, the initial positive voltage may be applied until a light transmittance due to the initial positive voltage becomes close to a maximum light transmittance of the sustain positive voltage, and then the step of applying the sustain positive voltage may be performed.

[0069] The positive sustain voltage may be changed according to a voltage corresponding to a target transmittance to be realized, that is, when the target transmittance increases, the positive sustain voltage may also increase, and when the target transmittance decreases, the positive sustain voltage may also decrease.

[0070] The magnitude of the positive sustain voltage may be smaller than the magnitude of the initial positive voltage. In particular, the magnitude of the positive sustain voltage may be less than 100% of the magnitude of the initial positive voltage. In particular, the magnitude of the positive sustain voltage may be 5% to 90% of the magnitude of the initial positive voltage. More particularly, the magnitude of the positive sustain voltage may be 20% to 70% of the magnitude of the initial positive voltage. More particularly, the magnitude of the positive sustain voltage may be 30% to 60% of the magnitude of the initial positive voltage. More particularly, the magnitude of the positive sustain voltage may be 40% to 50% of the magnitude of the initial positive voltage.

[0071] Also, the positive sustain voltage may have a voltage magnitude such that the maximum light transmittance of the positive sustain voltage is 70% or more of the maximum light transmittance of the initial positive voltage.

[0072] In detail, the positive sustain voltage may have a voltage magnitude having a maximum light transmittance of 70% to 99% of the maximum light transmittance of the initial positive voltage. More specifically, the positive sustain voltage may have a voltage magnitude having a maximum light transmittance of 80% to 90% of the maximum light transmittance of the initial positive voltage.

[0073] If the magnitude of the positive sustain voltage is less than 5% of the magnitude of the initial positive voltage, the maximum light transmittance of the positive sustain voltage becomes too small, which may reduce the overall light transmittance of the light path control member and decrease visibility.

[0074] In addition, if the magnitude of the sustain positive voltage is a voltage magnitude having a light transmittance of 70% or more of the maximum light transmittance of the initial positive voltage, the maximum light transmittance of the sustain positive voltage may be too small, resulting in a decrease in the overall light transmittance of the light path control member, thereby reducing visibility.

[0075] [Table 1]

[0076] [Table 2]

[0077] 5 and 6 are diagrams illustrating the relative light transmittance according to the magnitude of the sustain positive voltage when the initial positive voltage is 40 V. Table 1 shows the light transmittance according to FIG. 5, and Table 2 shows the light transmittance according to FIG. 6.

[0078] FIG. 5 and Table 1 are diagrams for explaining the light transmittance when positive voltages of 40V, 30V, 20V, and 10V are applied individually, and FIG. 6 and Table 2 are diagrams for explaining the light transmittance when positive voltages of 40V, 10V, 8V, and 5V are applied continuously.

[0079] 5 and Table 1, the light transmittance at positive voltages of 30V, 20V, and 10V is 85% or more higher than the light transmittance at a positive voltage of 40V.

[0080] Also, referring to FIG. 6 and Table 2, the light transmittance at positive voltages of 10V, 8V, and 5V is 70% or more at a positive voltage of 40V.

[0081] That is, referring to FIGS. 5, 6, Tables 1 and 2, it can be seen that the visibility of the light path control member can be maintained because the positive maintenance voltage has a magnitude of 5% or more of the initial positive voltage, or the light transmittance due to the positive maintenance voltage is 70% or more of the light transmittance of the initial positive voltage.

[0082] In the section where the positive sustain voltage is applied, the maximum light transmittance due to the positive sustain voltage may be maintained.

[0083] For example, when the initial positive voltage is applied for a time period during which the light transmittance reaches a value lower than the maximum light transmittance of the positive sustain voltage, the light transmittance may increase to the maximum light transmittance of the positive sustain voltage during the period during which the positive sustain voltage is applied, and then the light transmittance may be maintained.

[0084] Alternatively, when the initial positive voltage is applied for a time period required to reach a light transmittance equal to the maximum light transmittance of the positive sustain voltage, the light transmittance reached in the section in which the positive sustain voltage is applied may be maintained in the section in which the positive sustain voltage is applied.

[0085] Alternatively, when the initial positive voltage is applied for a time required to reach a light transmittance greater than the maximum light transmittance of the positive sustain voltage, the light transmittance may be decreased to the maximum light transmittance of the positive sustain voltage during the period in which the positive sustain voltage is applied, and then the light transmittance may be maintained.

[0086] Meanwhile, the step of applying the positive sustain voltage may have a plurality of magnitudes of sustain voltage.

[0087] For example, the step of applying a positive sustain voltage may include a first positive sustain voltage and a second positive sustain voltage.

[0088] In particular, the magnitude of the first positive sustain voltage may be smaller than the magnitude of the initial positive voltage, and the magnitude of the second positive sustain voltage may be smaller than the magnitude of the first positive sustain voltage.

[0089] That is, when the magnitude of the positive voltage corresponding to the target light transmittance is the second positive maintenance voltage, as the application time of the initial positive voltage increases, the step of applying the initial positive voltage may reach a first light transmittance higher than the target light transmittance, and the step of applying the positive maintenance voltage may decrease the light transmittance by the magnitude of the second positive maintenance voltage, changing to the second light transmittance, which is the target light transmittance.

[0090] In this case, if the difference between the first light transmittance and the second light transmittance is large, a sudden change in light transmittance may cause a decrease in user visibility. Therefore, the first positive sustain voltage, which acts as a buffer, may be introduced between the initial positive voltage and the second positive sustain voltage to prevent a sudden change in light transmittance due to the difference in light transmittance.

[0091] Alternatively, the first positive sustain voltage may be smaller than the initial positive voltage, and the second positive sustain voltage may be larger than the first positive sustain voltage.

[0092] That is, when the magnitude of the positive voltage corresponding to the target light transmittance is the second positive maintenance voltage, as the application time of the initial positive voltage decreases, the step of applying the initial positive voltage may reach a first light transmittance lower than the target light transmittance, and the step of applying the positive maintenance voltage may increase the light transmittance by the magnitude of the second positive maintenance voltage, changing to the second light transmittance, which is the target light transmittance.

[0093] In this case, if the difference between the first light transmittance and the second light transmittance is large, a sudden change in light transmittance may cause a decrease in user visibility. Therefore, the first positive sustain voltage, which acts as a buffer, may be introduced between the initial positive voltage and the second positive sustain voltage to prevent a sudden change in light transmittance due to the difference in light transmittance.

[0094] In the privacy mode, a voltage may be applied. In particular, a negative voltage or a positive voltage may be applied in the privacy mode. In particular, a voltage of a polarity opposite to that of the voltage in the public mode may be applied. For example, when a positive voltage is applied in the public mode, a negative voltage may be applied in the privacy mode, and when a negative voltage is applied in the public mode, a positive voltage may be applied in the privacy mode. For convenience of explanation, the following description will focus on the case where a negative voltage is applied in the privacy mode.

[0095] That is, in the privacy mode, a negative voltage is applied between the first electrode 210 and the second electrode 220. As a result, the entire light conversion particles 330b may be redispersed and arranged in the dispersion liquid 330a. Therefore, in the privacy mode, the receiving unit may be operated as a light blocking unit.

[0096] The privacy mode may include applying a negative voltage and applying a rest voltage. In particular, in the privacy mode, the negative voltage may be applied first, and then the rest voltage may be applied.

[0097] The steps of applying the initial positive voltage, applying the sustain positive voltage, applying the negative voltage, and applying the rest voltage may be performed in sequence.

[0098] The step of applying the negative voltage may be a step of moving the light conversion particles 330b. In particular, the light conversion particles 330b may be redispersed in the dispersion liquid 330a by applying a negative voltage to the negatively charged light conversion particles 330b.

[0099] At this time, the magnitude (absolute value) of the negative voltage may be the same as or different from the magnitude of the initial positive voltage. In particular, the magnitude of the negative voltage may be 80% to 120% of the magnitude of the initial positive voltage.

[0100] As a result, a negative voltage is applied again with a magnitude equal to the initial positive voltage, so that the light conversion particles can be effectively dispersed.

[0101] Meanwhile, the step of applying the negative voltage may be driven by a pulse voltage. In particular, the step of applying the negative voltage may include a pulse voltage that alternates between a positive voltage and a negative voltage. Here, the pulse voltage may refer to a voltage that alternately applies a voltage having a period shorter than the voltage application time in the public mode.

[0102] As a result, by applying the negative voltage, the light conversion particles 330b are dispersed within the dispersion liquid 330a while repeatedly moving toward the first electrode 210 and the second electrode 220, so that the light conversion particles can be uniformly dispersed within the dispersion liquid 330a.

[0103] The step of applying the rest voltage may apply a voltage of 0 V. That is, in the step of applying the rest voltage, no voltage may be applied.

[0104] The step of applying the rest voltage may be a step of relieving stress of the light-converting particles 330b. That is, the light-converting particles 330b react to the application of the positive and negative voltages, gradually giving stress to the particles, and if such stress is repeatedly accumulated, a phenomenon in which the light-converting particles are stuck together may occur.

[0105] Therefore, the light path control member of the embodiment includes a step of applying a rest voltage and a step of stabilizing the light conversion particles 330b, which can relieve the stress accumulated in the light conversion particles 330b, thereby preventing aggregation of the light conversion particles.

[0106] The time for applying the rest voltage may be the same as or longer than the time for applying the initial positive voltage. The step of applying the rest voltage may be 5 seconds or more. In particular, the step of applying the rest voltage may be 10 seconds or more. In particular, the step of applying the rest voltage may be 15 seconds or more. In particular, the step of applying the rest voltage may be 20 seconds or more. If the step of applying the rest voltage is less than 5 seconds, the stress accumulated in the light conversion particles may not be sufficiently relieved, and clumping of the light conversion particles may occur.

[0107] The light path control member according to the embodiment may include applying voltages of different magnitudes when driven into the open mode by applying a voltage.

[0108] In particular, the method can include the steps of applying an initial voltage and applying a sustain voltage.

[0109] That is, the light path control member according to the embodiment may first apply an initial voltage greater than the sustain voltage magnitude, quickly drive at a transmittance adjacent to the target transmittance, and then reduce the voltage to a relatively low sustain voltage to drive the open mode at the target transmittance.

[0110] As a result, the open mode is driven with a low sustain voltage, so that the stress on the light conversion particles caused by a high voltage can be alleviated, and the clumping phenomenon of the light conversion particles can be minimized.

[0111] This allows the display device to be driven in the public mode with a uniform transmittance for a long period of time without any decrease in the transmittance in the public mode.

[0112] Also, by rapidly changing the transmittance depending on the initial voltage, the drawback of delayed driving time due to low voltage can be compensated for.

[0113] In other words, the optical path control member of the embodiment can reduce the driving time by using a high initial voltage, while preventing the agglomeration of optical conversion particles by using a low maintenance voltage, thereby improving the driving characteristics, driving speed, and reliability of the optical path control member.

[0114] Furthermore, the light path control member according to the embodiment may include a step of applying a quiescent voltage of 0V for a certain period of time during conversion from the privacy mode to the public mode.

[0115] This includes a step of relieving stress on the light conversion particles accumulated in the public mode and the privacy mode, so that clumping of the light conversion particles can be prevented.

[0116] As a result, the light transmittance can be prevented from decreasing even when the public mode and the privacy mode are repeatedly operated, and the life of the light path control member can be improved.

[0117] Hereinafter, the present invention will be described in more detail through measurements of transmittance of light path control members according to examples and comparative examples. These examples are presented only as examples to describe the present invention in more detail. Therefore, the present invention is not limited to these examples.

[0118] Meanwhile, the light transmittance of the light path control member described below can be defined as the light transmittance measured by (B / A)*100 after measuring the luminance (A) of light emitted from the light source in a state in which the light path control member is not arranged and the luminance (B) of light emitted from the light source at an angle of 45° through the light path control member by placing the light path control member on the light source.

[0119] Example 1 A positive voltage of +40V was applied to the light path control element in the initial mode with no voltage applied, and then the voltage was reduced to a positive voltage of +10V to convert the light path control element into the public mode, and the change in light transmittance for 1 minute was measured.

[0120] At this time, a positive voltage of +40V was applied until the light transmittance reached 101% to 130% of the maximum light transmittance at the positive voltage of +10V.

[0121] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0122] Next, the above-mentioned positive and negative voltages were repeatedly applied, and the change in light transmittance in the open mode was continuously measured for 5 and 10 minutes.

[0123] Example 2 A positive voltage of +40V was applied to the light path control element in the initial mode with no voltage applied, and then the voltage was reduced to a positive voltage of +10V to convert the light path control element into the public mode, and the change in light transmittance for 1 minute was measured.

[0124] At this time, a positive voltage of +40V was applied until the light transmittance reached 101% to 130% of the maximum light transmittance at the positive voltage of +10V.

[0125] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0126] Next, the above-mentioned positive and negative voltages were repeatedly applied, and the change in light transmittance was continuously measured in the open mode for 1 hour and 30 minutes.

[0127] Comparative Example A positive voltage of +40V was applied to the light path control element in the initial mode where no voltage was applied, to convert the light path control element into the public mode, and then the change in light transmittance was measured for 10 minutes.

[0128] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0129] Then, the above positive and negative voltages were repeatedly applied, and the change in light transmittance in the open mode was continuously measured for 5 minutes, 10 minutes, 30 minutes, 1 hour, 30 minutes, 10 minutes, 5 minutes, and 1 minute.

[0130] 7 and 8, the light path control members according to Examples 1 and 2 show almost no change in light transmittance in the open mode during the application of a sustain voltage of 10 V. In particular, referring to Fig. 8, it can be seen that the change in light transmittance is less than 1% even after 1 hour and 30 minutes has passed.

[0131] Meanwhile, referring to FIG. 9, it can be seen that the light path control member according to Comparative Example 1 has a very large change in light transmittance in the public mode when a voltage of 40V is applied.

[0132] In other words, the optical path control member according to the embodiment can maintain the optical transmittance for a long time in the open mode by alleviating the particle stress of the optical conversion particles through the initial constant voltage and the maintenance constant voltage, thereby preventing the aggregation of the optical conversion particles.

[0133] Example 3 A positive voltage of +40V was applied for 20 seconds to the light path control element in the initial mode with no voltage applied, and then the voltage was reduced to a positive voltage of +30V and applied for 10 seconds to convert the light path control element into the public mode.

[0134] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0135] Next, the power consumption of the optical path control component was measured according to the magnitude of the positive voltage and the negative voltage.

[0136] Example 4 A positive voltage of +40V was applied for 20 seconds to the light path control element in the initial mode with no voltage applied, and then the voltage was reduced to a positive voltage of +20V and applied for 10 seconds to convert the light path control element into the public mode.

[0137] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0138] Next, the power consumption of the optical path control component was measured according to the magnitude of the positive voltage and the negative voltage.

[0139] Example 5 A positive voltage of +40V was applied for 20 seconds to the light path control element in the initial mode with no voltage applied, and then the voltage was reduced to a positive voltage of +10V and applied for 10 seconds to convert the light path control element into the public mode.

[0140] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0141] Next, the power consumption of the optical path control component was measured according to the magnitude of the positive voltage and the negative voltage.

[0142] Comparative Example 2 A positive voltage of +40 V was applied for 20 seconds to the light path control element in the initial mode to which no voltage was applied, thereby converting the light path control element into the public mode.

[0143] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0144] Next, the power consumption of the optical path control component was measured according to the magnitude of the positive voltage and the negative voltage.

[0145] Comparative Example 3 A positive voltage of +40V was applied for 20 seconds to the light path control element in the initial mode to which no voltage was applied, and then a positive voltage of +40V was applied for 10 seconds to convert the light path control element into the public mode.

[0146] Next, after applying a voltage of −40 V, the voltage was adjusted to 0 V to convert the light path control component into the privacy mode.

[0147] Next, the power consumption of the optical path control component was measured according to the magnitude of the positive voltage and the negative voltage.

[0148] [Table 3]

[0149] [Table 4]

[0150] Referring to Tables 3 and 4, it can be seen that the light path controlling components according to Examples 3 to 5 have lower power consumption than the light path controlling components according to Comparative Examples 2 and 3.

[0151] In other words, the light path control elements according to Examples 3 to 5 operate at a lower voltage in the open mode compared to the light path control elements according to Comparative Examples 2 and 3, and therefore it is possible to reduce the overall power consumption of the light path control element.

[0152] Example 6 A positive voltage of +40 V was applied for 20 seconds to the light path control element in the initial mode to which no voltage was applied, thereby converting the light path control element into the public mode.

[0153] Next, a voltage of −40 V was applied for 3 seconds to convert the light path control member into the privacy mode.

[0154] Next, a rest voltage step was carried out in which a 0V state was maintained for 5 seconds so that no voltage was applied, and the device was again converted to the initial mode.

[0155] The public mode, privacy mode, and rest voltage step were defined as one cycle, and this cycle was repeated for 100 cycles or more.

[0156] The change in light transmittance in the open mode was then measured at each cycle. Comparative Example 4 A positive voltage of +40 V was applied for 20 seconds to the light path control element in the initial mode to which no voltage was applied, thereby converting the light path control element into the public mode.

[0157] Next, a voltage of −40 V was applied for 3 seconds to convert the light path control member into the privacy mode.

[0158] When the above-mentioned conversion to the public mode and the privacy mode without a quiescent voltage step is regarded as one cycle, this was repeated for more than 100 cycles.

[0159] The change in light transmittance in the open mode was then measured at each cycle. Referring to FIG. 10, it can be seen that the light transmittance of the light path control component according to Example 6, which includes a quiescent voltage step in which the 0V state is maintained, remains almost unchanged after switching from the public mode to the privacy mode.

[0160] On the other hand, referring to FIG. 11, it can be seen that the light transmittance of the light path control member according to the comparative example, which switches from the public mode to the privacy mode and then immediately switches back to the public mode, decreases as the period is repeated.

[0161] In other words, the optical path control member of the embodiment includes a rest voltage step, which relieves the stress on the optical conversion particles applied in the public mode and the privacy mode, thereby preventing aggregation of the optical conversion particles even when the cycle is repeated, thereby improving the life of the optical path control member.

[0162] Hereinafter, a display device and a display apparatus to which an optical path controlling member according to an embodiment is applied will be described with reference to FIGS.

[0163] 12 and 13, the light path control member 1000 according to the embodiment may be disposed above or below the display panel 2000. In the embodiment shown in FIG.

[0164] The display panel 2000 and the light path control member 1000 may be disposed to be adhered to each other. For example, the display panel 2000 and the light path control member 1000 may be adhered to each other via an adhesive member 1500. The adhesive member 1500 may be transparent. For example, the adhesive member 1500 may include an adhesive or an adhesive layer including an optically transparent adhesive material.

[0165] The adhesive member 1500 may include a release film. In particular, when adhering the light path member and the display panel, the release film may be removed before adhering the light path control member and the display panel.

[0166] The display panel 2000 may include a first' substrate 2100 and a second' substrate 2200. When the display panel 2000 is a liquid crystal display panel, the light path control member may be formed under the liquid crystal panel. That is, when the surface of the liquid crystal panel that a user views is defined as the upper part of the liquid crystal panel, the light path control member may be disposed under the liquid crystal panel. The display panel 2000 may be formed in a structure in which a first' substrate 2100 including a thin film transistor (TFT) and a pixel electrode and a second' substrate 2200 including a color filter layer are bonded together with a liquid crystal layer sandwiched therebetween.

[0167] Also, the display panel 2000 may be a liquid crystal display panel having a COT (color filter on transistor) structure in which a thin film transistor, a color filter, and a black electrolyte are formed on a first' substrate 2100, and a second' substrate 2200 is bonded to the first' substrate 2100 with a liquid crystal layer sandwiched therebetween. That is, a thin film transistor may be formed on the first' substrate 2100, a protective film may be formed on the thin film transistor, and a color filter layer may be formed on the protective film. Also, a pixel electrode in contact with the thin film transistor may be formed on the first' substrate 2100. At this time, in order to improve the aperture ratio and simplify the mask process, the black electrolyte may be omitted, and the common electrode may be formed to function as the black electrolyte.

[0168] In addition, when the display panel 2000 is a liquid crystal display panel, the display device may further include a backlight unit 3000 for providing light to a rear surface of the display panel 2000 .

[0169] That is, as shown in FIG. 12 , the light path control member may be disposed below the liquid crystal panel and above the backlight unit 3000, and the light path control member may be disposed between the backlight unit 3000 and the display panel 2000.

[0170] Alternatively, as shown in FIG. 13, when the display panel 2000 is an organic light emitting diode panel, the light path control member may be formed on the upper part of the organic light emitting diode panel. That is, when the surface of the organic light emitting diode panel that a user views is defined as the upper part of the organic light emitting diode panel, the light path control member may be disposed on the upper part of the organic light emitting diode panel. The display panel 2000 may include a self-emitting element that does not require a separate light source. The display panel 2000 may include a first' substrate 2100 on which a thin film transistor is formed, and an organic light emitting element in contact with the thin film transistor is formed. The organic light emitting element may include a positive electrode, a negative electrode, and an organic light emitting layer formed between the positive electrode and the negative electrode. In addition, a second' substrate 2200 acting as an encapsulation substrate for encapsulation may be further included on the organic light emitting element.

[0171] Although not shown in the drawings, a polarizer may be further disposed between the light path control member 1000 and the display panel 2000. The polarizer may be a linear polarizer or an external light anti-reflection polarizer. For example, when the display panel 2000 is a liquid crystal display panel, the polarizer may be a linear polarizer. Also, when the display panel 2000 is an organic light emitting diode panel, the polarizer may be an external light anti-reflection polarizer.

[0172] An additional functional layer 1300, such as an anti-reflection layer or an anti-glare layer, may be further disposed on the light path controlling member 1000. In particular, the functional layer 1300 may be attached to one surface of the first substrate 110 of the light path controlling member. Although not shown in the drawings, the functional layer 1300 may be attached to the first substrate 110 of the light path controlling member via an adhesive layer. A release film for protecting the functional layer may be further disposed on the functional layer 1300.

[0173] In addition, a touch panel may be further disposed between the display panel and the light path control member.

[0174] Although the drawings show the light path control member being disposed on the top of the display panel, the embodiment is not limited thereto, and the light control member may be disposed in various positions where light can be adjusted, such as the bottom of the display panel or between the second substrate and the first substrate of the display panel.

[0175] In addition, although the optical conversion parts of the optical path control members according to the embodiments are shown in the drawings to be parallel or perpendicular to the outer surface of the second substrate, the optical conversion parts may be formed to be inclined at a certain angle to the outer surface of the second substrate, thereby reducing the moire phenomenon occurring between the display panel and the optical path control member.

[0176] 14 to 16, the light path control member according to the embodiment can be applied to various display devices.

[0177] 14 to 16, the light path control member according to the embodiment can be applied to a display device that displays a display.

[0178] For example, when power is applied to the optical path control member as shown in FIG. 14, the accommodating portion functions as a light-transmitting portion and the display device is driven in a light-blocking mode, and when power is not applied to the optical path control member as shown in FIG. 15, the accommodating portion functions as a light-blocking portion and the display device is driven in a light-blocking mode.

[0179] This allows a user to easily drive the display device into the privacy mode or the general mode by applying power.

[0180] Light emitted from the backlight unit or the self-luminous elements may travel from the first substrate to the second substrate, or light emitted from the backlight unit or the self-luminous elements may travel from the second substrate to the first substrate.

[0181] Furthermore, referring to FIG. 16, a display device to which the light path control member according to the embodiment is applied may also be applied inside a vehicle.

[0182] For example, a display device including an optical path control member according to an embodiment may display an image for checking vehicle information and a vehicle travel route. The display device may be disposed between a driver's seat and a passenger seat of a vehicle.

[0183] In addition, the light path control member according to the embodiment may be applied to an instrument panel that displays vehicle speed, engine speed, warning signals, and the like.

[0184] Moreover, the light path control member according to the embodiment can be applied to the front glass (FG) or the left and right window glasses of a vehicle.

[0185] The features, structures, effects, etc. described in the above-mentioned embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person having ordinary skill in the art to which the embodiment belongs. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

[0186] In addition, although the above description has focused on the embodiments, these are merely illustrative and do not limit the present invention, and a person having ordinary skill in the art to which the present invention pertains will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the present embodiments. For example, each component specifically illustrated in the embodiments can be modified and implemented. Differences related to such modifications and applications should be interpreted as being included in the scope of the present invention as defined in the appended claims.

Claims

1. A first substrate; A first electrode disposed on the first substrate; A second substrate disposed on the first substrate; A second electrode disposed below the second substrate; a light conversion unit disposed between the first electrode and the second electrode; the light conversion unit includes a partition wall and a housing unit, the container contains a dispersion liquid and light conversion particles dispersed in the dispersion liquid; The container is driven in a public mode or a privacy mode according to a type of voltage applied to the first electrode or the second electrode; the receiving unit is driven in an open mode by applying an initial positive voltage and a sustain positive voltage to the first electrode or the second electrode; the accommodation section is driven in a privacy mode by applying a negative voltage to the first electrode or the second electrode; the application of the initial positive voltage, the application of the sustain positive voltage, and the application of the negative voltage are performed sequentially; the magnitude of the initial positive voltage is greater than the magnitude of the sustain positive voltage; When the operation mode is changed from the privacy mode to the public mode, a rest voltage is applied for a certain time before applying the initial positive voltage and the sustain positive voltage to the first electrode or the second electrode to which the negative voltage is applied, and The rest voltage is 0V.

2. The optical path control member of claim 1 , wherein the optical transmittance achieved depending on the application time of the initial positive voltage is the same as or different from the maximum optical transmittance when the sustain positive voltage is applied.

3. 3. The optical path control member of claim 2, wherein the application time of the initial positive voltage is a time until the optical transmittance due to the initial positive voltage becomes 70% to 130% of the maximum optical transmittance of the sustain positive voltage.

4. The optical path control member according to claim 1 , wherein the magnitude of the sustain positive voltage varies depending on a target transmittance.

5. As the target transmittance increases, the sustain positive voltage increases; The optical path control member according to claim 4 , wherein the sustain positive voltage is reduced as the target transmittance is reduced.

6. 2. The optical path control component according to claim 1, wherein the magnitude of the sustain positive voltage is 5% to 90% of the magnitude of the initial positive voltage.

7. 2 . The optical path control member according to claim 1 , wherein the sustain positive voltage has a voltage magnitude at which a maximum optical transmittance of the sustain positive voltage is 70% or more of a maximum optical transmittance of the initial positive voltage.

8. 2. The optical path control member of claim 1, wherein the sustain positive voltage has a voltage magnitude such that the maximum optical transmittance of the sustain positive voltage is 70% to 90% of the maximum optical transmittance of the initial positive voltage.

9. the sustain positive voltages include a first sustain positive voltage and a second sustain positive voltage, The optical path control member according to claim 1 , wherein a magnitude of the first sustaining positive voltage is different from a magnitude of the second sustaining positive voltage.

10. the magnitude of the first sustaining positive voltage is less than the magnitude of the initial positive voltage; The optical path control member according to claim 9 , wherein a magnitude of the second sustaining positive voltage is smaller than a magnitude of the first sustaining positive voltage.

11. the sustain positive voltages include a first sustain positive voltage and a second sustain positive voltage, the magnitude of the first sustaining positive voltage is less than the magnitude of the initial positive voltage; The optical path control member according to claim 1 , wherein a magnitude of the second sustaining positive voltage is greater than a magnitude of the first sustaining positive voltage.

12. The light path control member according to claim 1 , wherein the privacy mode includes applying a pulse voltage.

13. The optical path control member according to claim 1 , wherein the quiescent voltage is applied for 5 seconds or more when the operation mode is changed from the privacy mode to the public mode.

14. The light path control member according to claim 1 , wherein the light conversion particles have negatively charged surfaces.

15. a panel including at least one of a display panel and a touch panel; and the light path control member of claim 1 disposed above or below the panel.

Images