Display device

Abstract

One embodiment of a display device includes a display unit, a light guide plate disposed below the display unit, a first light source unit disposed on one side of the light guide plate and irradiating light toward the light guide plate, and a second light source unit disposed below the light guide plate and irradiating light toward the light guide plate, wherein the light guide plate includes an emission surface pattern, the emission surface pattern is formed on the upper surface from which light is emitted, the longitudinal direction of the emission surface pattern is the first direction, the emission surface pattern includes irregularities, and the irregularities are arranged alternately and continuously in a second direction intersecting the first direction.

Description

Technical Field

[0001] This specification relates to a display device, and more particularly to a display device provided inside a vehicle.

Background Art

[0002] The content described herein merely provides background information for this specification and does not constitute the prior art.

[0003] Entering the full-fledged information era, the field of display devices that visually display electrical information signals has been rapidly developing, and research has been continuously conducted to improve the performance of various display devices, such as thinning, lightening, and reducing power consumption.

[0004] These display devices include liquid crystal display devices (LCD), quantum dot display panel devices (QD), field emission display devices (FED), electro-wetting display devices (EWD), and organic light emitting display devices (OLED), etc.

[0005] Display devices have been miniaturized, portable for users to carry and move, and developed to be attached to mobile devices such as vehicles, and improved to be more conveniently utilized by users.

[0006] Also, display devices have been continuously improved to increase the resolution and brightness of the screen and provide clear images to users.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The information described herein is provided solely as background information to this specification and does not constitute prior art.

[0008] With the arrival of the full-fledged information age, the field of display devices, which visually display electrical information signals, is developing rapidly, and research is continuously being conducted to improve the performance of various display devices, such as making them thinner, lighter, and lowering their power consumption.

[0009] These display devices include liquid crystal display devices (LCDs), quantum dot display panel devices (QDs), field emission display devices (FEDs), electro-wetting display devices (EWDs), and organic light-emitting display devices (OLEDs).

[0010] Display devices have been miniaturized and developed to be portable or mountable on vehicles and other mobile devices, making them more convenient for users to use.

[0011] Furthermore, display devices are continuously being improved to enhance screen resolution and brightness, providing users with clearer images. [Means for solving the problem]

[0012] One embodiment of a display device includes a display unit, a light guide plate disposed below the display unit, a first light source unit disposed on one side of the light guide plate and irradiating light toward the light guide plate, and a second light source unit disposed below the light guide plate and irradiating light toward the light guide plate, wherein the light guide plate includes an emission surface pattern, the emission surface pattern is formed on the upper surface from which light is emitted, the longitudinal direction of the emission surface pattern is the first direction, the emission surface pattern includes irregularities, and the irregularities may be arranged alternately and continuously in a second direction intersecting the first direction.

[0013] The exit surface pattern is formed by injection molding using a mold, and the mold can be polished with an abrasive tool so that a formation pattern corresponding to the exit surface pattern is formed on the mold.

[0014] The formation pattern can be formed by moving the polishing tool in a first direction.

[0015] The light guide plate includes a first region on which an emission surface pattern is formed, and a second region located on one side of the first region on which an emission surface pattern is formed, wherein the depth of the emission surface pattern in the first region is smaller than the depth of the emission surface pattern in the second region, and the first light source can be positioned closer to the second region than to the first region.

[0016] In the second region, the depth of the emission surface pattern may increase continuously as the emission surface pattern progresses toward the first light source.

[0017] The light guide plate may include a bottom pattern positioned on its lower surface so as to protrude toward the second light source, and a side pattern positioned on its side so as to protrude toward the first light source.

[0018] The bottom surface pattern may be formed in a pyramidal shape, and the area of ​​the first surface facing the first light source may be configured to be larger than the area of ​​the second surface facing the opposite direction from the first light source.

[0019] The longitudinal direction of the side pattern is the second direction, and the side pattern may include multiple side patterns, which may be arranged to be spaced apart from each other in a third direction that intersects the first and second directions.

[0020] The cross-sectional shape obtained by cutting the side pattern in a third direction is a semicircular or semi-elliptical shape that protrudes convexly from the side of the light guide plate, and the side pattern may have a constant width along the second direction.

[0021] The display unit includes a shared area where the displayed image can be seen by all users in front of the display unit, and a variable personal area where the displayed image can be selectively seen by all or some users. The shared area may overlap with the first area in at least a portion, and the variable personal area may overlap with the second area in at least a portion.

[0022] When the first light source is turned on, the image displayed on the variable personal area can be seen by all users, and when the first light source is turned off, the image displayed on the variable personal area can be seen by only some users.

[0023] The display unit may include a display panel on which an image is reproduced, a cover member positioned above the display panel, and an optical sheet positioned below the display panel, into which light that has passed through a light guide plate is incident.

[0024] One embodiment of the display device may include a light control film disposed below the light guide plate, an optical member disposed between the light control film and the second light source unit, and a reflector disposed below the second light source unit. [Effects of the Invention]

[0025] In the display device according to this specification, the upper surface of the light guide plate is formed such that the unevenness changes greatly and becomes deeper in the second direction. As a result, the light emitted onto the upper surface of the light guide plate undergoes significant scattering, refraction, diffraction, total internal reflection on the surface, etc. in the second direction, significantly suppressing the searchlight phenomenon and making the luminance of the light emitted from the light guide plate uniform.

[0026] Further, in the display device according to this specification, the emission surface pattern may be configured such that the width increases as it approaches the first light source unit.

[0027] With such a structure, in the portion adjacent to the first light source unit where the searchlight phenomenon is prominent on the upper surface of the light guide plate, unevenness is deeply formed in the second direction by the emission surface pattern, and the searchlight phenomenon can be effectively removed.

[0028] On the other hand, in the portion far from the first light source unit where the searchlight phenomenon is weak on the upper surface of the light guide plate, unevenness is shallowly formed in the second direction by the emission surface pattern, and the luminance of the light emitted from the light guide plate can be increased.

[0029] Also, in manufacturing the light guide plate described in this specification, the polishing tool is continuously moved in the first direction with respect to the mold, and the depth at which the polishing tool and the mold come into contact is changed according to each region to form scratches on the surface of the mold, thereby manufacturing a formation pattern with different depths in the first direction.

[0030] Therefore, in order to manufacture a formation pattern with different depths in the first direction, there is no need to separately cut each part of the mold with a cutting tool, so the mold can be easily manufactured, shortening the manufacturing time of the light guide plate and effectively saving the manufacturing cost.

[0031] Also, since the mold is not cut using a separate cutting tool, machining defects of the mold due to cutting can be reduced, and the overall manufacturing cost of the mold can be reduced.

[0032] The effects described above, as well as the specific effects of the present invention, will be explained and described below in relation to the embodiments for carrying out the invention. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic cross-sectional view of a display device according to one embodiment. [Figure 2] This is a diagram illustrating the searchlight phenomenon that occurs in a light guide plate. [Figure 3] This is a perspective view of a light guide plate according to one embodiment. [Figure 4] This is a view of Figure 3 from a different direction. [Figure 5a] This is a plan view of a light guide plate according to one embodiment. [Figure 5b] This is a cross-sectional view taken along the 5-5' direction in Figure 5a. [Figure 6] This is a front view of a light guide plate according to one embodiment. [Figure 7] This figure shows a portion of the bottom surface of a light guide plate according to one embodiment. [Figure 8] This is a magnified view of a portion of Figure 6. [Figure 9] This is a right side view of Figure 6. [Figure 10] This is a front view of a light guide plate according to one embodiment. [Figure 11] This is a cross-sectional view of the mold at point A, which corresponds to the point shown on the light guide plate in Figure 10. [Figure 12] This is a cross-sectional view of the mold at point B, which corresponds to the point shown on the light guide plate in Figure 10. [Figure 13] This is a cross-sectional view of the mold at point C, which corresponds to the point shown on the light guide plate in Figure 10. [Modes for carrying out the invention]

[0034] The aforementioned objectives, features, and advantages will be described in detail below with reference to the accompanying drawings, so that a person with ordinary skill in the art to which this specification belongs can easily implement the technical concept of this specification. In describing this specification, if a specific description of known technology relating to this specification is deemed to obscure the gist of this specification, the detailed description will be omitted. Hereafter, preferred embodiments according to this specification will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0035] Although terms such as "first," "second," etc., are used to indicate various components, these components are not limited by these terms. These terms are simply used to distinguish one component from another, and unless otherwise specified, the first component may also be the second component.

[0036] Throughout the specification, unless otherwise stated, each component may be singular or plural.

[0037] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as “composed of” or “including” in this application should not be interpreted as necessarily including all of the multiple components or stages described in the specification, but rather as meaning that some of the components or stages may not be included, or that further components or stages may be included.

[0038] Throughout the specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0039] Furthermore, when display devices are used on a daily basis, the terms "front" or "back" may be used to describe the position of an object. In this case, "front" refers to the +X direction in the drawing, and "back" refers to the -X direction in the drawing.

[0040] The display device according to the embodiments of this specification can variably provide a shared mode in which both the driver and the assistant can view the displayed image, and a personal mode in which a portion of the image in front of the assistant can be viewed only by the assistant and not by the driver.

[0041] These functional modes are referred to as Switchable Privacy Modes (SPM). Some vehicle display devices may be equipped with an SPM area to implement the SPM function.

[0042] In these SPM areas, images that can be viewed only by the assistant may be displayed in a variable manner. Whether the images in the SPM area are in a shared mode that can be viewed by both the driver and the assistant, or in a personal mode that can be viewed only by the assistant, may be selected by controlling the brightness of the light on the display unit on which the images are played.

[0043] In other words, if the brightness of the display is high, it may enter shared mode, and if the brightness of the display is low, it may enter personal mode.

[0044] Thus, multiple light sources may be provided in the display device to adjust the brightness of the display. By blinking some of the multiple light sources to adjust the brightness of the light in the display, the SPM area can be variably switched between shared mode and individual mode.

[0045] Multiple light sources may be arranged sequentially below the display unit on which the image is played. Light sources located close to the display unit, i.e., above it, may be positioned to illuminate the display device laterally.

[0046] In such cases, a light guide plate may be placed to change the path of the light. On the other hand, the light guide plate can also serve to change the multiple point light sources provided in the light source unit into a face light source and emit it.

[0047] As light travels through the light guide plate, a phenomenon can occur where the point light source gradually changes into a surface light source. Consequently, the area of ​​light incident on the light guide plate may exhibit uneven light intensity, resulting in a repetitive pattern of light and dark areas. These phenomena are known as the searchlight phenomenon.

[0048] When the searchlight phenomenon occurs in the light guide plate, the uniformity of light decreases, which can degrade the image quality of the image reproduced on the display. Improvement is needed to address this. The embodiments of this specification will be described in detail below.

[0049] Figure 1 is a schematic cross-sectional view of a display device according to one embodiment. The display device according to one embodiment may include a display unit 100, a light guide plate 200, a first light source unit 300, and a second light source unit 400.

[0050] The display unit 100 can display video and images. In the following, the objects displayed on the display unit 100 can be a mix of video, images, and other visuals. A user is positioned in front of the display unit 100, and the user can obtain information necessary for driving and other desired information from the images displayed on the display unit 100.

[0051] The display unit 100 may include a display panel 110, a cover member 120, and an optical sheet 130.

[0052] The display panel 110 has multiple pixels arranged horizontally and vertically, and can reproduce an image by changing the color of each pixel. The cover member 120 is positioned above the display panel 110 and can protect the display panel 110.

[0053] The optical sheet 130 is positioned below the display panel 110, allowing light that has passed through the light guide plate 200 to enter it. The optical sheet 130 diffuses the incident light, further uniformizing the brightness of the light across the entire optical sheet 130 before emission.

[0054] The optical sheet 130 may be configured in a form in which multiple sheets having different functions are laminated together.

[0055] For example, the optical sheet 130 may include a diffusion sheet, a prism sheet, and a protective sheet. The diffusion sheet diffuses light. Light that passes through the diffusion sheet is diffused and can become even more uniform.

[0056] The prism sheet is placed above the diffusion sheet and can improve the straight-line propagation of light. Because the prism sheet has a prism structure, it can partially focus the light that enters after passing through the diffusion sheet, thereby improving the straight-line propagation of light.

[0057] The protective sheet may be placed outside the diffusion sheet or prism sheet. The protective sheet can protect the diffusion sheet and prism sheet from damage caused by external foreign objects or scratches.

[0058] The display unit 100 may include a shared area 101 and a variable personal area 102. The shared area 101 allows all users in front of the display unit 100 to view the displayed image. In a display device installed in a vehicle, the shared area 101 may be positioned close to the driver.

[0059] The variable personal area 102 can selectively display images to all users or only some users. The variable personal area 102 may be positioned close to an assistant sitting next to the driver. The area of ​​the shared area 101 may be larger than the area of ​​the variable personal area 102.

[0060] The display device of the embodiment includes a plurality of light sources, namely a first light source 300 and a second light source 400, which are arranged to be spaced apart from each other and can be turned on / off by independent control.

[0061] When the first light source unit 300 is in a heated state and emits light, the variable personal area 102 may be configured so that all users can see the displayed image, and when the first light source unit 300 is in an off state, the variable personal area 102 may be configured so that only some users can see the displayed image.

[0062] The second light source 400 may remain lit while the display device is operating. Alternatively, by blinking the first light source 300 to adjust the brightness of the light in the display unit 100, the display unit 100 can operate in a shared mode where both the driver and the assistant can view the image, or in a personal mode where the image displayed in the variable personal area 102 can only be viewed by the assistant.

[0063] This utilizes the fact that if the brightness of the display unit 100 is moderately low, a driver who views the variable personal area 102 at an angle will not be able to see the image displayed in the variable personal area 102.

[0064] To implement these SPM (Switchable Privacy Mode) functions, multiple light sources are required, some of which need to blink while the display device is operating. In this embodiment, the first light source unit 300 blinks to implement either shared mode or private mode.

[0065] The light guide plate 200 may be positioned below the display unit 100. The light guide plate 200 can convert an incident point light source into a face light source and emit light from it.

[0066] Light emitted from the first light source unit 300 enters the light guide plate 200, where it undergoes repeated total internal reflection, diffuse reflection, refraction, and diffraction to be converted into a surface light source with uniform brightness, which can then be emitted toward the display unit 100.

[0067] Light emitted from the first light source unit 300 enters the side surface of the light guide plate 200, altering the path of the light so that it can be emitted towards the display unit 100 located above the light guide plate 200.

[0068] The first light source unit 300 is positioned on one side of the light guide plate 200 and can irradiate light toward the light guide plate 200. The light source unit in this specification may consist of an LED that serves as a light source and a circuit board on which the LED is mounted. The first light source unit 300 is arranged along one side edge of the light guide plate 200 such that a plurality of LEDs are spaced apart from each other, and these LEDs may be mounted on the circuit board.

[0069] As mentioned above, in shared mode, the first light source 300 is turned on, and the brightness of the light from the display unit 100 becomes relatively high, while in personal mode, the first light source 300 is turned off, and the brightness of the light from the display unit 100 may become relatively low.

[0070] The second light source unit 400 is positioned below the light guide plate 200 and can irradiate light toward the light guide plate 200. The point light source emitted from the second light source unit 400 passes through the optical member 600 and the light control film 500, which will be described later, enters the light guide plate 200, and then exits the light guide plate 200 to enter the display unit 100.

[0071] The second light source unit 400 may include a plurality of LEDs arranged at intervals from each other in the X-axis and Y-axis directions on an XY plane perpendicular to the Z-axis direction in Figure 1, and a circuit board on which the LEDs are mounted.

[0072] One embodiment of the display device may include a light control film 500, an optical element 600, and a reflector 700.

[0073] The light control film 500 may be placed below the light guide plate 200. By irradiating the light control film 500 from the second light source unit 400 and adjusting the transmittance of the light that has passed through the optical element 600, the contrast between light and dark in the displayed image can be increased, thereby improving the clarity of the image.

[0074] Light can be incident on the portion of the light-control film 500 adjacent to the first light source 300 from the first light source 300. To allow the light incident on the light-control film 500 from the first light source 300 to travel upward, i.e., in the +Z direction, a plurality of light-reflecting diaphragms 510 may be arranged in the portion of the light-control film 500 adjacent to the first light source 300 so as to be separated from each other in a first direction.

[0075] These diaphragms 510 can improve the brightness of the display unit 100 and enhance the light efficiency of the display device.

[0076] The optical component 600 may be placed between the light control film 500 and the second light source unit 400. The optical component 600 may have a structure in which parts having different functions are laminated. For example, the optical component 600 may include a diffusion layer and a prism layer.

[0077] The diffusion layer can diffuse the point light source incident on the second light source unit 400, converting it into a surface light with uniform brightness. The prism layer, equipped with a prism structure, can partially focus the incident light, improving the straightness of the light's propagation.

[0078] The reflector 700 may be positioned below the second light source unit 400. The reflector 700 can reflect light emitted downward from the second light source unit 400 and change the path of the light so that it travels upward towards the display unit 100.

[0079] Therefore, by directing almost all of the light emitted from the second light source unit 400 towards the display unit 100, the light efficiency of the display device can be increased.

[0080] Figure 2 is a diagram illustrating the searchlight 40 phenomenon that occurs in the light guide plate 200. Figure 2 shows the screen of the display unit 100 with no video playback, the first light source unit 300 turned on, and the display unit 100 screen being viewed. Figure 2 shows a display device equipped with a light guide plate 200 in which the emission surface pattern 210, which will be described later, is not formed.

[0081] When light from the first light source 300 enters the light guide plate 200, a phenomenon may occur in which the point light source gradually changes to a surface light source as the light travels along the light guide plate 200. Consequently, the area of ​​the light guide plate 200 into which the light enters may have uneven light intensity, and a phenomenon may occur in which bright and dark areas are repeatedly arranged. These phenomena are referred to as the searchlight phenomenon.

[0082] In the display device, the screen of the display unit 100 when these searchlight 40 phenomena occur is shown in Figure 2.

[0083] Referring to Figure 2, in the area where light enters the display unit 100, the light does not diffuse sufficiently into the light guide plate 200, so the light emitted from each LED maintains the form of a point source.

[0084] This shows that on the screen of the display unit 100, the light repeatedly changes in a second direction at the light incidence site, that is, it becomes darker in the second direction and then brighter, and the light maintains the shape of the light ray.

[0085] These searchlight 40 phenomena disappear as the light continues to travel along the light guide plate 200. This is because, as the light continues to travel, it diffuses more effectively in the second direction, resulting in a more uniform light intensity.

[0086] In other words, these searchlight 40 phenomena are more pronounced in the portion of the light guide plate 200 adjacent to the first light source, and become weaker as the distance from the first light source increases. Considering these characteristics of the searchlight 40 phenomenon, a structure that effectively suppresses the searchlight 40 and improves the light efficiency of the light guide plate 200 will be specifically described below.

[0087] In this specification, "light efficiency" may mean the efficiency of suppressing light brightness unevenness, such as the searchlight 40 phenomenon, without reducing the light brightness.

[0088] Figure 3 is a perspective view of the light guide plate 200 according to one embodiment. Figure 4 is a view of Figure 3 from another direction.

[0089] The light guide plate 200 may include an emission surface pattern 210 in order to suppress the aforementioned searchlight 40 phenomenon and improve the uniformity of the emitted light.

[0090] The emission surface pattern 210 may be formed on the upper surface of the light guide plate 200 from which light is emitted. The longitudinal direction of the emission surface pattern 210 may be the first direction. The emission surface pattern 210 may have irregularities. These irregularities may be arranged in a continuous manner in a second direction intersecting the first direction.

[0091] Figure 5a is a plan view of the light guide plate 200 according to one embodiment. Figure 5b is a cross-sectional view taken along the 5-5' direction in Figure 5a.

[0092] As shown in Figure 5b, in the ejection surface pattern 210, convex and concave portions may be arranged alternately in a continuous manner along the second direction, i.e., the Y-axis. However, the shapes of the convex and concave portions arranged in the second direction may be different from each other.

[0093] In this case, the convex and concave portions constituting the ejection surface pattern 210 are formed by polishing the mold 20 and using the polished mold 20 in an injection molding manner. Therefore, the shapes of the convex and concave portions formed by polishing and arranged in the second direction may not be constant but irregular.

[0094] The light-emitting surface pattern 210 may be formed on the surface of the light guide plate 200 from which light is emitted. That is, the light-emitting surface pattern 210 may be formed on the upper surface of the light guide plate 200 and may be formed to extend linearly in a first direction. That is, the light-emitting surface pattern 210 may be formed to extend linearly in the X-axis direction. The light-emitting surface pattern 210 may be provided in a form in which irregularities are arranged alternately and continuously in a second direction, i.e., in the Y-axis direction.

[0095] Light is emitted from the light guide plate 200 and undergoes scattering, refraction, diffraction, and total internal reflection on the emission surface pattern 210, thereby achieving uniform brightness in the XY plane.

[0096] In particular, the emission surface pattern 210 can diffuse light in a second direction, thereby suppressing the aforementioned searchlight 40 phenomenon. To effectively suppress the searchlight 40 phenomenon, the light needs to diffuse significantly in the second direction.

[0097] The emission surface pattern 210 in the embodiment may be arranged in a first direction whose longitudinal direction is parallel to the direction of propagation of light emitted from the first light source unit 300. Therefore, the upper surface of the light guide plate 200 has little to no change in irregularities in the first direction.

[0098] On the other hand, the emission surface pattern 210 may be provided in multiple locations and arranged to be spaced apart from each other in the second direction. Therefore, the upper surface of the light guide plate 200 has large and deep variations in its surface irregularities in the second direction.

[0099] The multiple LEDs in the first light source unit 300 are arranged to be spaced apart from each other in the second direction, and each LED can form a point light source. For these reasons, the searchlight 40 phenomenon exhibits a pattern in which high brightness and low brightness alternate repeatedly in the second direction.

[0100] In this embodiment, as described above, the upper surface of the light guide plate 200 is formed such that the change in surface irregularities is large and deep in the second direction. Therefore, the light emitted from the upper surface of the light guide plate 200 undergoes significant scattering, refraction, diffraction, and total internal reflection in the second direction, which significantly suppresses the searchlight 40 phenomenon and makes the brightness of the light emitted from the light guide plate 200 uniform.

[0101] As shown in Figure 2, the searchlight 40 phenomenon can decrease as the light propagates. This is because the light becomes more diffuse and gradually more uniform as it propagates. The emission surface pattern 210 needs to be formed taking these light propagation characteristics into consideration.

[0102] The emission surface pattern 210 allows for greater uniformity of brightness as the depth of the irregularities on the upper surface of the light guide plate 200 increases, resulting in more pronounced scattering, refraction, diffraction, and total internal reflection.

[0103] However, while these emission surface patterns 210 can suppress the searchlight 40 phenomenon and improve brightness uniformity, they may also weaken the directivity of light, thereby reducing the overall brightness of the emitted light.

[0104] Considering this, the emission surface pattern 210 needs to have deeper irregularities in areas where the searchlight 40 phenomenon is pronounced, and shallower irregularities in areas where the searchlight 40 phenomenon is weak, in order to increase the brightness of the light and improve light efficiency.

[0105] Therefore, the emission surface pattern 210 may be configured such that its depth increases as it approaches the first light source unit 300.

[0106] With this structure, the area adjacent to the first light source 300 where the searchlight 40 phenomenon is significant on the upper surface of the light guide plate 200 is formed with deep irregularities in the second direction by the emission surface pattern 210, thereby effectively eliminating the searchlight 40 phenomenon.

[0107] On the other hand, in areas of the upper surface of the light guide plate 200 that are far from the first light source 300 where the searchlight 40 phenomenon is weak, shallow irregularities can be formed in a second direction by the emission surface pattern 210 to increase the brightness of the light emitted from the light guide plate 200. The structure of the light guide plate 200 will be described in more detail below.

[0108] The light guide plate 200 may include a first region 201 and a second region 202. The first region 201 may have an emission surface pattern 210 formed thereon, and the second region 202 may be located on one side of the first region 201 and may also have an emission surface pattern 210 formed thereon. The depth of the emission surface pattern 210 in the first region 201 is formed to be smaller than the depth of the emission surface pattern 210 in the second region 202, and the first light source unit 300 may be located closer to the second region 202 than to the first region 201.

[0109] In other words, in the first region 201, the depth of the emission surface pattern 210, i.e., the depth of the recess, is relatively small. The first region 201 is a region in the light guide plate 200 that is relatively far from the incident surface of light irradiated from the first light source unit 300. The second region 202 is a region where the depth of the emission surface pattern 210, i.e., the depth of the recess, is relatively large, and it is a region that is relatively close to the incident surface of light.

[0110] Therefore, the first light source unit 300 adjacent to the light incident surface of the light guide plate 200 may be positioned closer to the second region 202 than to the first region 201.

[0111] The depth of the emission surface pattern 210 in the second region 202 may increase continuously (gradually) as it progresses toward the first light source unit 300. That is, the depth of the emission surface pattern 210 may increase continuously (gradually) as it approaches the incident surface of light in the light guide plate 200.

[0112] With this structure, in the first region 201 where the searchlight 40 phenomenon in the light guide plate 200 is weak, the irregularities caused by the emission surface pattern 210 are formed to be shallow, and the brightness of the light emitted from the light guide plate 200 can be increased.

[0113] Furthermore, in the second region 202 where the searchlight 40 phenomenon is pronounced in the light guide plate 200, the depths of the emission surface pattern 210 are configured to differ from each other in the first direction. When the searchlight 40 phenomenon is pronounced, the irregularities of the emission surface pattern 210 are made deeper, and when the searchlight 40 phenomenon gradually decreases, the irregularities of the emission surface pattern 210 are made shallower, thereby increasing the light efficiency.

[0114] As mentioned above, the searchlight 40 phenomenon is relatively weak in the shared area 101 of the display unit 100, while it is relatively pronounced in the variable personal area 102. Therefore, the first area 201 is located in a position corresponding to the shared area 101, and the second area 202 is located in a position corresponding to the variable personal area 102.

[0115] With this structure, the common area 101 of the display unit 100 may overlap with the first area 201 in at least a portion, and the variable personal area 102 of the display unit 100 may overlap with the second area 202 in at least a portion.

[0116] Of course, the shared area 101 and the first area 201 are not positioned to perfectly coincide with each other, nor are the variable personal areas 102 and the second area 202 positioned to perfectly coincide with each other.

[0117] Figure 6 is a front view of the light guide plate 200 according to one embodiment. Figure 7 shows a part of the bottom surface of the light guide plate 200 according to one embodiment. Figure 8 is an enlarged view of a part of Figure 6. The arrows in Figure 8 indicate that the path of light emitted from the bottom surface of the light guide plate 200 is altered by the bottom surface pattern 220.

[0118] The light guide plate 200 may include a bottom surface pattern 220 that is positioned to protrude toward the second light source unit 400 on its lower surface. Multiple bottom surface patterns 220 may be provided, and as shown in Figure 4, each bottom surface pattern 220 may be arranged on the XY plane at regular intervals in the first and second directions.

[0119] The lower surface pattern 220 can improve the light efficiency of the display device by reflecting the light emitted from the first light source unit 300 when it is emitted from the lower surface of the light guide plate 200, thereby changing the path of the light and causing it to enter the light guide plate 200 again.

[0120] In this case, the lower surface pattern 220 is a transparent structure through which light passes, but the path of the light can be changed by totally reflecting the light emitted from the lower surface pattern 220.

[0121] The lower surface pattern 220 may be formed in a pyramidal shape, and the area of ​​the first surface 221 facing the first light source unit 300 may be larger than the area of ​​the second surface 222 facing in the opposite direction from the first light source unit 300.

[0122] With this structure, as shown in Figure 8, the first inclination of the second surface 222, which faces in the opposite direction to the first light source 300, may be steeper than the first inclination of the first surface 221, which faces the first light source 300, in the first direction.

[0123] Therefore, the light emitted from the lower surface of the light guide plate 200 undergoes total internal reflection at the first surface 221, which is formed by a relatively steep inclined surface. This abruptly changes the path of the light, allowing it to re-enter the light guide plate 200.

[0124] Figure 9 is a right side view of Figure 6. As shown in Figure 9, the light guide plate 200 may include a side pattern 230 positioned on its side so as to protrude toward the first light source unit 300. The side pattern 230 may be formed on the light incident surface of the light guide plate 200 facing the first light source unit 300.

[0125] Light emitted from the first light source 300 passes through the side pattern 230, undergoing scattering, refraction, diffraction, etc., and diffusing, which can improve the uniformity of the light incident on the light guide plate 200. The side pattern 230, together with the exit surface pattern 210, can reduce the searchlight 40 phenomenon.

[0126] The wider the side pattern 230, the better the uniformity of the light, but the less bright the light may be. Therefore, the width of the side pattern 230 can be appropriately selected, taking into consideration this point and the area of ​​the incident surface of the light guide plate 200.

[0127] The longitudinal direction of the side pattern 230 may be the second direction. The side pattern 230 may include a plurality of side patterns. These plurality of side patterns may be arranged to be spaced apart from each other in a third direction that intersects the first and second directions.

[0128] The LEDs of the first light source unit 300 may include a plurality of LEDs. These plurality of LEDs may be arranged so as to be spaced apart from each other at regular intervals in a second direction. Therefore, the longitudinal direction of the first light source unit 300 may be the second direction. Correspondingly, the longitudinal direction of each of the plurality of side patterns 230 may be the second direction. The plurality of side patterns 230 may be arranged so as to be spaced apart from each other in a third direction.

[0129] The shape of the cross-section obtained by cutting the side pattern 230 in a third direction may be a semicircular or semielliptical shape that protrudes convexly from the side of the light guide plate 200.

[0130] The side pattern 230 may be configured to have a constant width in the second direction. The incident surface of the light guide plate 200 on which the side pattern 230 is formed can be incident on a uniform point light source in the second direction. Accordingly, the side pattern 230 may be configured to have a constant width in the second direction in order to uniformly diffuse the light in the second direction.

[0131] The ejection surface pattern 210 may be formed by injection molding using a mold 20. Alternatively, the ejection surface pattern 210 with irregularities can be formed by directly polishing the upper surface of the light guide plate 200.

[0132] However, if the upper surface of the light guide plate 200 is polished, the transparency of the upper surface may decrease due to the polishing, which may obstruct the emission of light from the light guide plate 200 and reduce the light efficiency of the light guide plate 200. Therefore, it may be more appropriate to manufacture the emission surface pattern 210 by injection molding.

[0133] In order to form the injection-out surface pattern 210, the mold 20 may have a shape that corresponds to the shape of the injection-out surface pattern 210.

[0134] However, since the ejection surface pattern 210 is formed with different depths in the first direction, it can be somewhat difficult to form these shapes in the mold 20. Below, we will specifically describe a method for easily forming shapes corresponding to the ejection surface pattern 210 in the mold 20.

[0135] The mold 20 shown below is the part of the mold 20 used to injection mold the light guide plate 200 that is used to produce the shape of the upper surface of the light guide plate 200 and the injection surface pattern 210.

[0136] The mold 20 can be polished with an abrasive tool to form a shape on the surface of the mold 20 that corresponds to the injection surface pattern 210. The abrasive tool may be used to polish the surface of the mold 20 (by carving out or scratching the surface) to form a shape that corresponds to the injection surface pattern 210.

[0137] The mold 20 can be polished with a polishing tool so that a forming pattern 21 corresponding to the exit surface pattern 210 is formed on the mold 20. Since the light guide plate 200 is manufactured by injection molding, the forming pattern 21 of the mold 20 and the exit surface pattern 210 of the light guide plate 200 may have opposite orientations of the irregularities.

[0138] In other words, the recesses of the forming pattern 21 can become the protrusions of the exit surface pattern 210, and the protrusions of the forming pattern 21 can become the recesses of the exit surface pattern 210. Although the shapes are reversed in this way, the depths (H1, H2, H3) of the forming pattern 21 may be configured to correspond to the depths of the exit surface pattern 210.

[0139] The forming pattern 21 can be formed by moving the polishing tool in a first direction. The polishing tool may be configured to continuously advance in the first direction relative to the mold 20 to create the forming pattern 21, and the depth of contact with the mold 20 may change as it advances in the first direction.

[0140] The polishing tool may have continuously formed irregularities in the width direction. If the length of the polishing tool in the width direction matches or is longer than the length of the light guide plate 200 in the first direction, the manufacturing of the mold 20 can be completed by moving the polishing tool once in the first direction relative to the mold 20.

[0141] If the widthwise length of the polishing tool is shorter than the length of the light guide plate 200 in the first direction, the polishing tool can be moved multiple times in the first direction relative to the mold 20 to complete the manufacturing of the mold 20.

[0142] By continuously moving the polishing tool in a first direction relative to the mold 20, and changing the contact depth between the polishing tool and the mold 20 according to each region, scratches can be formed on the surface of the mold 20, thereby creating a formation pattern 21 with different depths in the first direction.

[0143] Therefore, since it is not necessary to separate and cut each part of the mold 20 with a separate cutting tool in order to produce forming patterns 21 of different depths in the first direction, the mold 20 can be easily manufactured, the manufacturing time of the light guide plate 200 can be shortened, and manufacturing costs can be effectively saved.

[0144] Figure 10 is a front view of a light guide plate 200 according to one embodiment. Figure 11 is a cross-sectional view of the mold 20 at point A, corresponding to the point shown on the light guide plate 200 in Figure 10. Figure 12 is a cross-sectional view of the mold 20 at point B, corresponding to the point shown on the light guide plate 200 in Figure 10. Figure 13 is a cross-sectional view of the mold 20 at point C, corresponding to the point shown on the light guide plate 200 in Figure 10.

[0145] In Figures 11 to 13, the depths of the formation pattern 21 (H1, H2, H3) can be said to be the average value of the depths of multiple recesses that differ slightly in depth.

[0146] When creating a pattern 21 on the mold 20, the polishing tool can contact the mold 20 at a relatively small depth in a position corresponding to the first region 201 of the mold 20, and at a relatively large depth in a position corresponding to the second region 202 of the mold 20.

[0147] The polishing tool may be configured such that, as it moves toward the direction corresponding to the first light source 300 at a position corresponding to the second region 202, the contact depth with the mold 20 increases continuously (gradually).

[0148] In Figures 11 to 13, point A belongs to the part of the mold 20 corresponding to the first region 201 of the light guide plate 200, and points B and C belong to the parts of the mold 20 corresponding to the second region 202 of the light guide plate 200. In particular, point C is one end of the exit surface pattern 210 on the light guide plate 200 where the width of the exit surface pattern 210 is maximum.

[0149] The depth of the formation pattern 21 at point A is minimal, and the depth of these formation patterns 21 can be maintained constant in the region corresponding to the first region 201. The depth (H1) of the formation pattern 21 at point A may be, for example, 0.1 μm. However, the depth (H1) is not limited to this.

[0150] The depth (H3) of the formation pattern 21 at point C may be, for example, 0.3 μm. However, the depth (H3) is not limited to this. The depth (H2) of the formation pattern 21 at point B may be, for example, greater than 0.1 μm and less than 0.3 μm. However, the depth (H2) is not limited to this.

[0151] The depth of the formation pattern 21 at point B may increase continuously (gradually) as it progresses in the direction corresponding to the first light source unit 300.

[0152] By manufacturing a mold 20 having the formation pattern 21 using the structure described above, and then using these molds 20 to perform injection molding, the light guide plate 200 according to the embodiment can be easily manufactured.

[0153] On the other hand, the width of the emission surface pattern 210 of the light guide plate 200 in the second direction, that is, the distance between adjacent recesses or between adjacent protrusions, may be, for example, 2 μm. However, the width of the emission surface pattern 210 in the second direction is not limited to this.

[0154] Furthermore, the width of the forming pattern 21 of the mold 20 may also correspond to the width of the emission surface pattern 210 of the light guide plate 200.

[0155] A display device according to one embodiment includes a display unit, a light guide plate disposed below the display unit, a first light source unit disposed on one side of the light guide plate and irradiating light toward the light guide plate, and a second light source unit disposed below the light guide plate and irradiating light toward the light guide plate, wherein the light guide plate includes an emission surface pattern, the emission surface pattern is formed on the upper surface from which light is emitted, the longitudinal direction of the emission surface pattern is a first direction, the emission surface pattern includes irregularities, and the irregularities may be arranged alternately and continuously in a second direction intersecting the first direction.

[0156] The ejection surface pattern is formed by injection molding using a mold, and the mold can be polished with a polishing tool so that a forming pattern corresponding to the ejection surface pattern is formed on the mold.

[0157] The forming pattern may be formed by moving the polishing tool in the first direction.

[0158] The light guide plate includes a first region on which the emission surface pattern is formed, and a second region located on one side of the first region on which the emission surface pattern is formed, wherein the depth of the emission surface pattern in the first region is smaller than the depth of the emission surface pattern in the second region, and the first light source may be located closer to the second region than to the first region.

[0159] In the second region, the depth of the emission surface pattern may increase continuously as the emission surface pattern progresses toward the first light source.

[0160] The light guide plate may include a bottom surface pattern positioned on its lower surface so as to protrude toward the second light source unit, and a side surface pattern positioned on its side so as to protrude toward the first light source unit.

[0161] The lower surface pattern may be formed in a pyramidal shape, and the area of ​​the first surface facing the first light source may be larger than the area of ​​the second surface facing the opposite direction from the first light source.

[0162] The longitudinal direction of the side pattern is the second direction, and the side pattern includes a plurality of side patterns, which may be arranged to be spaced apart from each other in a third direction intersecting the first and second directions.

[0163] The cross-sectional shape obtained by cutting the side pattern in the third direction is a semicircular or semielliptical shape that protrudes convexly from the side surface of the light guide plate, and the side pattern may have a constant width along the second direction.

[0164] The display unit includes a shared area where the displayed image can be viewed by all users in front of the display unit, and a variable personal area where the displayed image can be selectively viewed by all or some users, wherein the shared area may overlap with the first area in at least a portion, and the variable personal area may overlap with the second area in at least a portion.

[0165] When the first light source is turned on, the image displayed on the variable personal area can be seen by all users, and when the first light source is turned off, the image displayed on the variable personal area can be seen by only some users.

[0166] The display unit may include a display panel on which an image is reproduced, a cover member positioned above the display panel, and an optical sheet positioned below the display panel, into which light that has passed through the light guide plate is incident.

[0167] A display device according to one embodiment may include a light control film disposed below the light guide plate, an optical member disposed between the light control film and the second light source unit, and a reflector disposed below the second light source unit.

[0168] As described above, this specification has been explained with reference to the illustrative drawings, but it is clear that this specification is not limited to the embodiments and drawings disclosed herein, and that various modifications can be made by a person of the ordinary skill within the scope of the technical concept of this specification. Furthermore, even if the effects of the configuration described herein are not explicitly stated and explained in the embodiments described above, it is natural that the effects that can be predicted by such configuration should also be recognized.

Claims

1. The display unit, A light guide plate is positioned below the display unit, A first light source unit is positioned on one side of the light guide plate and irradiates light toward the light guide plate, A second light source unit is positioned below the light guide plate and irradiates light toward the light guide plate, Includes, The light guide plate includes an emission surface pattern, The aforementioned emission surface pattern is formed on the upper surface from which light is emitted. The longitudinal direction of the aforementioned ejection surface pattern is the first direction, The aforementioned ejection surface pattern includes irregularities, The aforementioned irregularities are arranged alternately and continuously in a second direction intersecting the first direction. Display device.

2. The aforementioned injection surface pattern is formed by injection molding using a mold. The mold is polished with a polishing tool so that a forming pattern corresponding to the injection surface pattern is formed on the mold. The display device according to claim 1.

3. The display device according to claim 2, wherein the forming pattern is formed by moving the polishing tool in the first direction.

4. The light guide plate is The first region where the aforementioned injection surface pattern is formed, A second region is located on one side of the first region, and the emission surface pattern is formed therein. Includes, The depth of the exit surface pattern in the first region is smaller than the depth of the exit surface pattern in the second region. The first light source is positioned closer to the second region than to the first region. The display device according to claim 1.

5. The display device according to claim 4, wherein in the second region, the depth of the emission surface pattern increases continuously as the emission surface pattern progresses toward the first light source unit.

6. The light guide plate is A lower surface pattern is positioned on the lower surface so as to protrude toward the second light source section, A side pattern is arranged on the side so as to protrude toward the first light source section, The display device according to claim 1, including the following:

7. The aforementioned lower surface pattern is formed in a pyramidal shape, The area of ​​the first surface facing the first light source is greater than the area of ​​the second surface facing the opposite direction from the first light source. The display device according to claim 6.

8. The longitudinal direction of the side pattern is the second direction, The aforementioned side pattern includes a plurality of side patterns, The plurality of side patterns are arranged so as to be separated from each other in a third direction that intersects the first and second directions. The display device according to claim 6.

9. The shape of the cross-section obtained by cutting the side pattern in the third direction is a semicircular or semielliptical shape that protrudes convexly from the side surface of the light guide plate. The side pattern has a constant width along the second direction, The display device according to claim 8.

10. The aforementioned display unit is The displayed image is viewed by all users in front of the display unit in a shared area, A variable personal area that allows all or some users to selectively view the displayed image, Includes, The shared area overlaps with the first area in at least a portion of it. The variable personal region overlaps with the second region in at least a portion thereof. The display device according to claim 4.

11. When the first light source is turned on, the image displayed on the variable personal area can be seen by all users. When the first light source is turned off, the image displayed on the variable personal area is configured to be viewable only by certain users. The display device according to claim 10.

12. The aforementioned display unit is A display panel on which images are played, A cover member positioned above the display panel, An optical sheet is positioned below the display panel, into which light that has passed through the light guide plate is incident; The display device according to claim 1, including the following:

13. A light control film is positioned below the light guide plate, An optical member disposed between the light control film and the second light source unit, A reflector positioned below the second light source unit, The display device according to claim 1, including the following:

Images