Display apparatus

Abstract

One embodiment of a display apparatus comprises: 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, for emit

Description

display device

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

[0002] The material described in this section merely provides background information for the present specification and does not constitute prior art.

[0003] As we enter the full-fledged information age, the field of display devices that visually display electrical information signals is rapidly developing, and research is continuing to develop various display devices with thinner, lighter, and lower power consumption performance.

[0004] Examples of such 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).

[0005] Display devices are being developed to be miniaturized so that users can carry them around or install them in moving devices such as vehicles, and are being improved to make them more convenient for users.

[0006] Additionally, display devices are continuously being improved to provide users with clearer images by increasing the resolution and brightness of the screen.

[0007] An embodiment of the present specification can provide a display device having a light guide plate having a structure capable of suppressing a searchlight phenomenon.

[0008] In addition, the embodiments of the present specification can provide a method for easily manufacturing a light guide plate and a display device equipped with a light guide plate manufactured by the method.

[0009] Embodiments of this specification can solve various problems in addition to those mentioned.

[0010] One embodiment of a display device includes a display unit; a light guide plate disposed on a lower side of 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 on a lower side of the light guide plate and irradiating light toward the light guide plate, wherein the light guide plate includes a plurality of emission surface patterns formed to protrude from an upper surface through which light is emitted, and arranged in a first direction with a longitudinal direction and spaced apart from each other in a second direction intersecting the first direction, and the emission surface patterns may be provided such that a width increases in a direction toward the first light source unit.

[0011] The emission pattern can be formed in a semicircle or semi-ellipse shape in which the cross-section cut in the second direction protrudes in relief from the upper surface of the light guide plate.

[0012] The light guide plate includes a first region in which an emission surface pattern is formed; and a second region disposed on one side of the first region in which an emission surface pattern is formed, wherein the width of the emission surface pattern of the first region is formed to be smaller than the width of the emission surface pattern of the second region, and the emission surface pattern in the second region may be provided such that the width continuously increases in the direction toward the first light source unit.

[0013] The exit surface pattern is formed by injection molding using a mold, and the mold may be provided with a forming groove that forms the exit surface pattern by being pressed by a pressing tool.

[0014] The press tool may be configured to continuously advance in a first direction relative to the mold to create a forming groove, and to have a different depth of contact with the mold as it advances in the first direction.

[0015] The press tool can contact the mold at a depth smaller than that at a position corresponding to the first area of ​​the mold.

[0016] The pressurizing tool may be provided so that the depth of contact with the mold continuously increases as it advances from a position corresponding to the second region toward a direction corresponding to the first light source portion.

[0017] The light guide plate may include a lower surface pattern arranged to protrude toward the second light source unit on the lower surface; and a side surface pattern arranged to protrude toward the first light source unit on the side surface.

[0018] The lower pattern may be provided in a pyramid shape, and the area of ​​the first surface facing the first light source may be larger than the area of ​​the second surface facing in the opposite direction of the first light source.

[0019] The side patterns may be provided in multiple numbers, with the longitudinal direction arranged in the second direction and spaced apart from each other in the third direction intersecting the first and second directions.

[0020] The side pattern may be formed in a semicircle or semi-ellipse shape with a cross-section cut in the third direction protruding in relief from the side of the light guide plate, and may be provided with a constant width in the second direction.

[0021] The display unit includes a public area in front of the display unit where all users can view the displayed image; and optionally, a variable private area where all users or only some users can view the displayed image, wherein the public area overlaps at least partly with the first area, and the variable private area overlaps at least partly with the second area.

[0022] When the first light source unit is on, the variable personal area can be provided so that all users can view the displayed image, and when the first light source unit is off, the variable personal area can be provided so that only some users can view the displayed image.

[0023] The display unit may include a display panel on which an image is reproduced; a cover member disposed on an upper side of the display panel; and an optical sheet disposed on a lower side of the display panel and onto which light passing through the light guide plate is incident.

[0024] One embodiment of the display device may include a light control film disposed on the lower side of a light guide plate; an optical member disposed between the light control film and a second light source unit; and a reflector disposed on the lower side of the second light source unit.

[0025] In the display device according to the present specification, the upper surface of the light guide plate is formed to have large and deep changes in the unevenness in the second direction, so that light emitted through the upper surface of the light guide plate undergoes significant scattering, refraction, diffraction, surface total reflection, etc. in the second direction, thereby significantly suppressing the searchlight phenomenon and at the same time making the brightness of the light emitted from the light guide plate uniform.

[0026] Additionally, in the display device according to the present specification, the emission pattern may be provided such that its width increases in the direction toward the first light source unit.

[0027] Due to this structure, the searchlight phenomenon can be effectively eliminated by forming deep unevenness in the second direction through the emission surface pattern in the area adjacent to the first light source section where the searchlight phenomenon is prominent on the upper surface of the light guide plate.

[0028] On the other hand, in the upper surface of the light guide plate, in a part far from the first light source where the searchlight phenomenon is weak, shallow unevenness can be formed in the second direction by the emission surface pattern to increase the brightness of the light emitted from the light guide plate.

[0029] In addition, when manufacturing a light guide plate according to the present specification, by continuously moving a pressing tool in a first direction relative to a mold and varying the depth of contact between the pressing tool and the mold in each area, forming grooves of different depths in the first direction can be manufactured. Furthermore, in this manner, one forming groove can be manufactured with a single movement.

[0030] Therefore, since there is no need to cut each part of the mold separately with a separate cutting tool to create forming grooves of different depths in the first direction, the mold can be easily manufactured, thereby reducing the manufacturing time of the light guide plate and effectively saving manufacturing costs.

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

[0032] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0033] Figure 1 is a schematic cross-sectional view of a display device according to one embodiment.

[0034] Figure 2 is a drawing for explaining the searchlight phenomenon occurring in a light guide plate.

[0035] Figure 3 is a perspective view of a light guide plate according to one embodiment.

[0036] Figure 4 is a drawing of Figure 3 viewed from a different direction.

[0037] Figure 5 is a plan view of a light guide plate according to one embodiment.

[0038] Figure 6 is a front view of a light guide plate according to one embodiment.

[0039] Fig. 7 is a drawing showing a portion of the bottom surface of a light guide plate according to one embodiment.

[0040] Figure 8 is an enlarged view of a portion of Figure 6.

[0041] Figure 9 is a right side view of Figure 6.

[0042] Figure 10 is a schematic diagram showing a mold and a pressing tool.

[0043] Fig. 11 is a front view of a light guide plate according to one embodiment.

[0044] Fig. 12 is a cross-sectional view of the mold at point A corresponding to the point shown in the light guide plate of Fig. 11.

[0045] Fig. 13 is a cross-sectional view of the mold at point B corresponding to the point shown in the light guide plate of Fig. 11.

[0046] Fig. 14 is a cross-sectional view of the mold at point C corresponding to the point shown in the light guide plate of Fig. 11.

[0047] The above-described objects, features, and advantages are described in detail below with reference to the attached drawings, so that those skilled in the art to which this specification pertains can easily implement the technical ideas of this specification. In describing this specification, if a detailed description of a known technology related to this specification is judged to unnecessarily obscure the gist of this specification, a detailed description thereof will be omitted. Hereinafter, preferred embodiments according to this specification will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0048] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0049] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0050] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0051] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C through D", this means C or more and D or less, unless otherwise stated.

[0052] In drawings, directions can be indicated using an orthogonal coordinate system. In the specification, the first direction refers to the X-axis direction, the second direction refers to the Y-axis direction, and the third direction refers to the Z-axis direction. Additionally, in the specification, upper and lower refer to the superior-subordinate relationship in the X-axis direction.

[0053] Additionally, when the display device is used in everyday life, front or rear may be mentioned to describe the position of the object, where front means the +X direction in the drawing and rear means the -X direction in the drawing.

[0054] The display device according to the embodiment of the present specification can variably provide a common mode in which both the driver and the assistant can view the displayed image, and a private mode in which an image is provided in a certain area in front of the assistant that only the assistant can view and the driver cannot see.

[0055] This functional mode is called Switchable Privacy Mode (SPM). Some vehicle display devices may be equipped with an SPM area to implement SPM functionality.

[0056] In this SPM area, images that are only visible to the assistant can be displayed variably. Whether the image in the SPM area is displayed in a shared mode for both the driver and assistant, or in a private mode for only the assistant, can be selected by controlling the brightness of the display unit where the image is played.

[0057] That is, if the brightness of the light in the display section is high, it can be a public mode, and if the brightness of the light in the display section is low, it can be a private mode.

[0058] To control the brightness of the display unit in this way, a plurality of light sources may be provided in the display device. By controlling the brightness of the light of the display unit by blinking some of the plurality of light sources, the SPM area can be variably switched between a public mode and a private mode.

[0059] A plurality of light sources may be sequentially arranged below the display unit on which the image is played. The light sources arranged close to the display unit, i.e., above the display unit, may be arranged to radiate light in a lateral direction of the display device.

[0060] In such cases, a light guide plate may be placed to change the light path. Meanwhile, the light guide plate may also play a role in changing the multiple point light sources provided in the light source unit into surface light sources and emitting them.

[0061] As light propagates through a light guide plate, a phenomenon can occur where a point light source gradually transforms into a surface light source. Consequently, the area where light enters the light guide plate can exhibit uneven luminance and a repetitive array of bright and dark areas. This phenomenon is referred to as the searchlight phenomenon.

[0062] When a searchlight phenomenon occurs in a light guide plate, the uniformity of light decreases, which can degrade the image quality of images displayed on the display. Improvements are needed to address this issue. The following describes in detail the embodiments of this specification.

[0063] 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).

[0064] The display unit (100) can display video and images. In the following, the objects displayed on the display unit (100) can be used interchangeably as video, image, or picture. A user is positioned in front of the display unit (100), and the user can obtain driving-related information and other desired information from the images displayed on the display unit (100).

[0065] The display unit (100) may include a display panel (110), a cover member (120), and an optical sheet (130).

[0066] The display panel (110) is equipped with a plurality of pixels arranged in the horizontal and vertical directions, and an image can be reproduced by changing the color of each pixel. The cover member (120) is arranged on the upper side of the display panel (110) and can protect the display panel (110).

[0067] The optical sheet (130) is placed on the lower side of the display panel (110), and light passing through the light guide plate (200) can be incident. The optical sheet (130) can diffuse the incident light and make the brightness of the light more uniform throughout the entire optical sheet (130) and then emit it.

[0068] The optical sheet (130) may be provided in a form in which multiple sheets having different functions are laminated on each other.

[0069] For example, the optical sheet (130) may include a diffusion sheet, a prism sheet, and a protective sheet. The diffusion sheet diffuses light, and light passing through the diffusion sheet is diffused to become more uniform light.

[0070] A prism sheet is placed above the diffusion sheet and can improve the straightness of light. Since the prism sheet has a prism structure, the prism sheet can partially collect light passing through the diffusion sheet and improve the straightness of light.

[0071] A protective sheet may be placed on the outside of the diffusion sheet or prism sheet. The protective sheet can protect the diffusion sheet or prism sheet from damage caused by external foreign substances or scratches.

[0072] The display unit (100) may include a public area (101) and a variable private area (102). The public area (101) allows all users in front of the display unit (100) to view the displayed image. In a display device equipped in a vehicle, the public area (101) may be positioned close to the driver.

[0073] The variable private area (102) can optionally display images to all or only some users. The variable private area (102) can be positioned close to the driver's assistant. The area of ​​the public area (101) may be larger than that of the variable private area (102).

[0074] The display device of the embodiment includes a plurality of light source units, i.e., a first light source unit (300) and a second light source unit (400), which are arranged spaced apart from each other and can be turned on / off by independent control.

[0075] When the first light source unit (300) is turned on and irradiates light, the variable personal area (102) can be provided so that all users can view the displayed image, and when the first light source unit (300) is turned off, the variable personal area (102) can be provided so that only some users can view the displayed image.

[0076] While the display device is operating, the second light source unit (400) can always be turned on. Meanwhile, by controlling the brightness of the light of the display unit (100) by blinking the first light source unit (300), the display unit (100) can operate in a public mode where both the driver and the assistant can view the image, or in a private mode where only the assistant can view the image displayed in the variable private area (102).

[0077] This is because, if the brightness of the display unit (100) is appropriately low, a driver looking at the variable personal area (102) in a slanted diagonal direction cannot see the image displayed on the variable personal area (102).

[0078] Implementing this Switchable Privacy Mode (SPM) function requires multiple light sources, some of which need to blink while the display device is operating. In an exemplary embodiment, the first light source (300) may blink to implement either a public mode or a private mode.

[0079] The light guide plate (200) can be placed on the lower side of the display unit (100). The light guide plate (200) can change an incident point light source into a surface light source and emit light.

[0080] The light irradiated from the first light source (300) is incident on the light guide plate (200) and is changed into a surface light source of uniform brightness through repeated total reflection, diffuse reflection, refraction, and diffraction inside the light guide plate (200) so that it can be emitted toward the display unit (100).

[0081] The light irradiated from the first light source (300) is incident on the side of the light guide plate (200) and the light path is changed so that it can be emitted toward the display unit (100) located on the upper side of the first light guide plate (200).

[0082] The first light source unit (300) is arranged on one side of the light guide plate (200) and can irradiate light toward the light guide plate (200). In the specification, the light source unit may be provided with an LED as a light source and a circuit board on which the LED is mounted. The first light source unit (300) may be configured such that a plurality of LEDs are spaced apart from each other and arranged along one edge of the light guide plate (200), and these LEDs may be mounted on the circuit board.

[0083] As described above, in the public mode, the first light source unit (300) is turned on, so that the light brightness of the display unit (100) is relatively high, and in the private mode, the first light source unit (300) is turned off, so that the light brightness of the display unit (100) is relatively low.

[0084] The second light source unit (400) is positioned on the lower side of the light guide plate (200) and can irradiate light toward the light guide plate (200). The point light irradiated from the second light source unit (400) passes through the optical member (600) and light control film (500) described below, enters the light guide plate (200), and then exits from the light guide plate (200) to enter the display unit (100).

[0085] The second light source unit (400) may be provided with a plurality of LEDs arranged at intervals in the X-axis and Y-axis directions on an XY plane perpendicular to the Z-axis direction in FIG. 1, and a circuit board on which the LEDs are mounted.

[0086] A display device of one embodiment may include a light control film (500), an optical member (600), and a reflector (700).

[0087] The light control film (500) can be placed on the lower side of the light guide plate (200). The light control film (500) controls the transmittance of light irradiated from the second light source (400) and passing through the optical member (600) to be emitted, thereby increasing the contrast of the displayed image and enhancing the clarity of the image.

[0088] In the light control film (500), light can be incident from the first light source unit (300) to a portion adjacent to the first light source unit (300). In order for the light incident from the first light source unit (300) to the light control film (500) to travel upward, i.e. in the +Z direction, a plurality of light-reflecting partitions (510) can be arranged spaced apart from each other in the first direction in the portion adjacent to the first light source unit (300) of the light control film (500).

[0089] This membrane (510) can play a role in improving the luminance of the display unit (100) and thus increasing the light efficiency of the display device.

[0090] The optical member (600) may be positioned between the light control film (500) and the second light source unit (400). The optical member (600) may be provided in a structure in which parts having different functions are laminated. For example, the optical member (600) may include a diffusion layer and a prism layer.

[0091] The diffusion layer can diffuse the point light incident on the second light source (400) and change it into surface light with uniform brightness. The prism layer has a prism structure to partially collect the incident light and improve the straightness of the light.

[0092] The reflector (700) may be placed on the lower side of the second light source unit (400). The reflector (700) may change the light path so that the light emitted toward the lower side of the second light source unit (400) is reflected and then transmitted toward the upper side of the display unit (100).

[0093] Accordingly, the light efficiency of the display device can be increased by directing almost all of the light irradiated from the second light source unit (400) toward the display unit (100).

[0094] Fig. 2 is a drawing for explaining the searchlight (40) phenomenon occurring in the light guide plate (200). Fig. 2 shows a state in which the screen of the display unit (100) is viewed while the first light source unit (300) is turned on and no image is played. Fig. 2 illustrates a case of a display device equipped with a light guide plate (200) on which the emission surface pattern (210) described below is not formed.

[0095] When light is incident on the light guide plate (200) from the first light source unit (300), a phenomenon may occur in which the point light source gradually changes into a surface light source as the light propagates through the light guide plate (200). Accordingly, a phenomenon may occur in which the brightness of the light is uneven and bright and dark areas are repeatedly arranged in the area where the light is incident on the light guide plate (200). This phenomenon is referred to as the searchlight (40) phenomenon.

[0096] The screen of the display unit (100) in which the searchlight (40) phenomenon has occurred in the display device is illustrated in FIG. 2.

[0097] Referring to Fig. 2, the light from the display unit (100) is not sufficiently diffused to the light guide plate (200) at the point where the light is incident, so the light emitted from each LED maintains the form of a point light source.

[0098] Due to this, it can be seen that the screen of the display unit (100) repeatedly changes from dark to bright in the second direction, that is, in the second direction, from the light incident area, and the light maintains the form of a light beam.

[0099] This searchlight (40) phenomenon disappears as the light continues to travel through the light guide plate (200). This is because as the light continues to travel, the light is effectively diffused in the second direction, making the brightness of the light uniform.

[0100] That is, it can be seen that this searchlight (40) phenomenon is distinct in the area adjacent to the first light source in the light guide plate (200) and becomes fainter as it moves away from the first light source. Considering the characteristics of this searchlight (40) phenomenon, a structure capable of effectively suppressing searchlight (40) and simultaneously increasing light efficiency in the light guide plate (200) is specifically described below.

[0101] In the specification, luminous efficiency may mean the efficiency of suppressing luminance unevenness of light, such as the searchlight (40) phenomenon, without reducing the luminance of light.

[0102] Fig. 3 is a perspective view of a light guide plate (200) according to one embodiment. Fig. 4 is a view of Fig. 3 viewed from another direction. The light guide plate (200) may include an emission surface pattern (210) to suppress the aforementioned searchlight (40) phenomenon and increase the uniformity of emitted light.

[0103] The emission pattern (210) is formed to protrude from the upper surface of the light guide plate (200) through which light is emitted, and may be provided in multiple numbers arranged in a first direction with the longitudinal direction and spaced apart from each other in a second direction intersecting the first direction.

[0104] The emission surface pattern (210) can be engraved and protruded on the surface from which light is emitted, i.e., the upper surface of the light guide plate (200). As the light is emitted from the light guide plate (200), it undergoes scattering, refraction, diffraction, surface total reflection, etc. by the emission surface pattern (210) and can have uniform brightness on the XY plane.

[0105] In particular, the emission pattern (210) can suppress the searchlight (40) phenomenon described above by spreading light in the second direction. In order to effectively suppress the searchlight (40) phenomenon, the light needs to be significantly spread in the second direction.

[0106] The emission pattern (210) of the embodiment may be arranged in a first direction in which the longitudinal direction is parallel to the direction in which light is irradiated from the first light source unit (300). Accordingly, the upper surface of the light guide plate (200) has little or no change in unevenness in the first direction.

[0107] On the other hand, the emission pattern (210) may be provided in multiple numbers and arranged spaced apart from each other in the second direction. Accordingly, the upper surface of the light guide plate (200) has a large and deep change in the unevenness in the second direction.

[0108] In the first light source unit (300), a plurality of LEDs are arranged spaced apart from each other in the second direction, and each LED can form a point light source. For this reason, the searchlight (40) phenomenon takes the form of repeatedly high and low brightness in the second direction.

[0109] In the embodiment, as described above, the upper surface of the light guide plate (200) is formed to have large and deep changes in the unevenness in the second direction, so that the light emitted from the upper surface of the light guide plate (200) undergoes significant scattering, refraction, diffraction, surface total reflection, etc. in the second direction, thereby significantly suppressing the searchlight (40) phenomenon and at the same time making the brightness of the light emitted from the light guide plate (200) uniform.

[0110] Fig. 5 is a plan view of a light guide plate (200) according to one embodiment. Fig. 6 is a front view of a light guide plate (200) according to one embodiment.

[0111] As illustrated in Figure 2, the searchlight (40) phenomenon may diminish as light propagates. This is because light diffuses more significantly as it propagates, gradually becoming more uniform. It is necessary to form an emission pattern (210) considering these light propagation characteristics.

[0112] As the unevenness of the upper surface of the light guide plate (200) becomes deeper due to the emission pattern (210), scattering, refraction, diffraction, and total surface reflection become more prominent, thereby increasing the uniformity of brightness.

[0113] However, although this emission pattern (210) can suppress the searchlight (40) phenomenon and increase the uniformity of brightness, it can also weaken the straightness of light and lower the overall brightness of the emitted light.

[0114] Considering this, the emission pattern (210) needs to form deep irregularities in areas where the searchlight (40) phenomenon is prominent, and form shallow irregularities in areas where the searchlight (40) phenomenon is weak to increase the brightness of light, thereby increasing light efficiency.

[0115] To this end, the emission pattern (210) may be provided so that its width increases in the direction toward the first light source (300).

[0116] Due to this structure, the searchlight (40) phenomenon can be effectively eliminated by forming deep unevenness in the second direction by the emission surface pattern (210) in the area adjacent to the first light source unit (300) where the searchlight (40) phenomenon is prominent on the upper surface of the light guide plate (200).

[0117] On the other hand, on the upper surface of the light guide plate (200), in a part far from the first light source (300) where the searchlight (40) phenomenon is weak, shallow unevenness in the second direction can be formed 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.

[0118] 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 arranged on one side of the first region (201) and have an emission surface pattern (210) formed thereon. The width of the emission surface pattern (210) of the first region (201) may be formed to be smaller than the width of the emission surface pattern (210) of the second region (202).

[0119] That is, the first region (201) is a region where the width of the emission pattern (210) is relatively small and is relatively far from the incident surface of the light irradiated from the first light source (300) on the light guide plate (200). The second region (202) is a region where the width of the emission pattern (210) is relatively large and is relatively close to the incident surface of the light.

[0120] In the second region (202), the width of the emission surface pattern (210) can continuously increase as it moves toward the first light source unit (300). That is, the width of the emission surface pattern (210) can continuously increase as it moves toward the light incident surface in the light guide plate (200).

[0121] Due to this structure, in the first region (201) where the searchlight (40) phenomenon is weak in the light guide plate (200), the brightness of the light emitted from the light guide plate (200) can be increased by forming shallow unevenness by the emission surface pattern (210).

[0122] In addition, in the second region (202) where the searchlight (40) phenomenon is prominent in the light guide plate (200), the width of the emission pattern (210) is provided differently in the first direction so that when the searchlight (40) phenomenon is prominent, the unevenness due to the emission pattern (210) is formed deeply, and when the searchlight (40) phenomenon gradually decreases, the unevenness due to the emission pattern (210) is formed gradually shallower, thereby increasing the light efficiency.

[0123] As described above, in the display unit (100), the searchlight (40) phenomenon is relatively weak in the public area (101), and the searchlight (40) phenomenon is relatively prominent in the variable private area (102). Therefore, the first area (201) is located at a position corresponding to the public area (101), and the second area (202) is located at a position corresponding to the variable private area (102).

[0124] Due to this structure, the public area (101) of the display unit (100) can overlap at least partly with the first area (201), and the variable private area (102) of the display unit (100) can overlap at least partly with the second area (202).

[0125] Of course, the public area and the first area (201) are not positioned in completely coincident positions, and similarly, the variable private area (102) and the second area (202) are not positioned in completely coincident positions.

[0126] Fig. 7 is a drawing showing a portion of the bottom surface of a light guide plate (200) according to one embodiment. Fig. 8 is an enlarged view of a portion of Fig. 6. In Fig. 8, the arrows illustrate that the path of light emitted to the bottom surface of the light guide plate (200) is changed by the bottom pattern (220).

[0127] The light guide plate (200) may include a lower surface pattern (220) arranged to protrude toward the second light source unit (400) on the lower surface. The lower surface pattern (220) is provided in multiple numbers, and as illustrated in FIG. 4, each lower surface pattern (220) may be arranged at a constant interval in the first direction and the second direction on the XY plane.

[0128] The lower pattern (220) can increase the light efficiency of the display device by reflecting the light irradiated from the first light source (300) and changing the light path when it is emitted to the lower surface of the light guide plate (200) and allowing it to enter the light guide plate (200) again.

[0129] At this time, the lower pattern (220) is a transparent structure through which light passes, but the light emitted from the lower pattern (220) can be totally reflected to change the optical path.

[0130] The lower pattern (220) is provided in a pyramid shape, and the area of ​​the first surface (221) facing the first light source unit (300) may be provided to be larger than the area of ​​the second surface (222) facing the opposite direction of the first light source unit (300).

[0131] Due to this structure, as shown in FIG. 8, the first slope of the second surface (222) facing in the opposite direction of the first light source unit (300) can be provided more steeply than the first slope of the first surface (221) facing the first light source unit (300).

[0132] Accordingly, the light emitted from the lower surface of the light guide plate (200) is totally reflected by the first surface (221) formed as a relatively steep slope, so that the light path is drastically changed and can be incident on the light guide plate (200) again.

[0133] Fig. 9 is a right side view of Fig. 6. As shown in Fig. 9, the emission pattern (210) may be formed in a semicircular or semi-elliptical shape in which the cross-section cut in the second direction protrudes in relief from the upper surface of the light guide plate (200).

[0134] The protruding height of the exit surface pattern (210) may be proportional to the width of the exit surface pattern (210). That is, as the width of the exit surface pattern (210) increases, the height of the exit surface pattern (210) may also increase proportionally.

[0135] The light guide plate (200) may include a side pattern (230) that is positioned to protrude toward the first light source unit (300) on the side. The side pattern (230) may be formed on the light incident surface of the light guide plate (200) that faces the first light source unit (300).

[0136] Light irradiated from the first light source (300) passes through the side pattern (230) and is diffused through scattering, refraction, diffraction, etc. by the side pattern (230), thereby improving the uniformity of light incident on the light guide plate (200). The side pattern (230) can reduce the searchlight (40) phenomenon together with the emission pattern (210).

[0137] The wider the width of the side pattern (230), the better the uniformity of light, but the brightness of light may decrease. Therefore, considering these points and the area of ​​the incident surface of the light guide plate (200), the width of the side pattern (230) can be appropriately selected.

[0138] The side patterns (230) may be provided in multiple numbers, with the longitudinal direction arranged in the second direction and spaced apart from each other in the third direction intersecting the first and second directions.

[0139] The LEDs of the first light source unit (300) are provided in multiple numbers arranged at regular intervals in the second direction, and accordingly, the first light source unit (300) can be arranged in the second direction in the longitudinal direction. Accordingly, correspondingly, the side patterns (230) can be provided in multiple numbers arranged in the second direction in the longitudinal direction and spaced apart from each other in the third direction.

[0140] The side pattern (230) may be formed in a semicircular or semi-elliptical shape in which the cross-section cut in the third direction protrudes in relief from the side of the light guide plate (200).

[0141] The side pattern (230) may be provided 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 may be provided so that a uniform point light source may be incident in the second direction. Accordingly, the side pattern (230) may be provided to have a constant width in the second direction to uniformly diffuse light in the second direction.

[0142] The exit surface pattern (210) can be formed by injection molding using a mold (20). To form the exit surface pattern (210), a shape corresponding to the shape of the exit surface pattern (210) can be formed in the mold (20).

[0143] However, since the exit surface pattern (210) is formed with a different width in the first direction, it may be somewhat difficult to form such a shape in the mold (20). Hereinafter, a method for easily forming a shape corresponding to the exit surface pattern (210) in the mold (20) will be described in detail.

[0144] Fig. 10 is a schematic diagram showing a mold (20) and a press tool (30). The mold (20) illustrated in Fig. 10 and below is a portion used to produce the shape of the upper surface of the light guide plate (200) and the emission surface pattern (210) in the entire mold (20) for injecting the light guide plate (200).

[0145] A mold (20) can be pressed by a pressing tool (30) to form a shape corresponding to an exit surface pattern (210). The mold (20) is provided with a forming groove (31) that is pressed by the pressing tool (30) to form an exit surface pattern (210), and the forming groove (31) can have a shape corresponding to the exit surface pattern (210).

[0146] The press tool (30) may be provided to continuously advance in a first direction with respect to the mold (20) to create a forming groove (31), and to have a different depth of contact with the mold (20) as it advances in the first direction.

[0147] By continuously moving the press tool (30) in a first direction with respect to the mold (20) and varying the depth of contact between the press tool (30) and the mold (20) in each area, forming grooves (31) having different depths in the first direction can be produced. In addition, in this manner, one forming groove (31) can be produced with one movement.

[0148] Accordingly, since there is no need to cut each part of the mold (20) separately with a separate cutting tool to produce a forming groove (31) with different depths in the first direction, the mold (20) can be easily produced, thereby reducing the production time of the light guide plate (200) and effectively saving the production cost.

[0149] Fig. 11 is a front view of a light guide plate (200) according to one embodiment. Fig. 12 is a cross-sectional view of a mold (20) at point A corresponding to the point illustrated in the light guide plate (200) of Fig. 11. Fig. 13 is a cross-sectional view of a mold (20) at point B corresponding to the point illustrated in the light guide plate (200) of Fig. 11. Fig. 14 is a cross-sectional view of a mold (20) at point C corresponding to the point illustrated in the light guide plate (200) of Fig. 11.

[0150] In the embodiment, the distance D between the adjacent emission surface patterns (210) in the second direction and the corresponding forming grooves (31) may be, for example, about 50 μm. However, the present invention is not limited thereto.

[0151] When the cross-section of the exit pattern is semicircular, the width of the exit pattern (210) may be twice the height of the exit pattern (210) and the depth of the forming groove (31). When the cross-section of the exit pattern is semi-elliptical, the width of the exit pattern (210) may be greater than twice the height of the exit pattern (210) and the depth of the forming groove (31). Hereinafter, a case in which the cross-section of the exit pattern is semicircular will be described as an example.

[0152] When forming a forming groove (31) in a mold (20), the pressure tool (30) can contact the mold (20) at a relatively small depth at a position corresponding to the first area (201) of the mold (20), and can contact the mold (20) at a relatively large depth at a position corresponding to the second area (202) of the mold (20).

[0153] The pressurizing tool (30) may be provided so that the depth of contact with the mold (20) continuously increases as it advances from a position corresponding to the second region (202) toward a direction corresponding to the first light source (300).

[0154] In FIGS. 12 to 14, point A belongs to a portion of the mold (20) corresponding to the first area (201) of the light guide plate (200), and points B and C belong to portions of the mold (20) corresponding to the second area (202) of the light guide plate (200). In particular, point C is one end of the emission surface pattern (210) in which the width of the emission surface pattern (210) in the light guide plate (200) is at its maximum.

[0155] At point A, the depth of the forming groove (31) is minimum, and the depth of this forming groove (31) can be maintained constant in the area corresponding to the first region (201). The depth H1 of the forming groove (31) at point A can be, for example, 0.1 μm. However, it is not limited thereto.

[0156] The depth H3 of the forming groove (31) at point C may be, for example, 10 μm. However, the present invention is not limited thereto. The depth H2 of the forming groove (31) at point B may be, for example, greater than 0.1 μm and less than 10 μm. However, the present invention is not limited thereto.

[0157] At point B, the depth of the forming groove (31) can continuously increase as it progresses toward the direction corresponding to the first light source unit (300).

[0158] By manufacturing a mold (20) having a forming groove (31) with the aforementioned structure, and by injection molding using this mold (20), a light guide plate (200) according to an embodiment can be easily manufactured.

[0159] A display device according to one embodiment includes: a display unit; a light guide plate disposed on a lower side of 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 on a lower side of the light guide plate and irradiating light toward the light guide plate, wherein the light guide plate includes a plurality of emission surface patterns formed to protrude from an upper surface through which light is emitted, arranged in a first direction in a longitudinal direction, and arranged spaced apart from each other in a second direction intersecting the first direction, and wherein the emission surface patterns may be provided such that a width increases in a direction toward the first light source unit.

[0160] The above-mentioned emission pattern may be formed in a semicircular or semi-elliptical shape in which a cross-section cut in the second direction protrudes in relief from the upper surface of the light guide plate.

[0161] The light guide plate may include a first region in which the emission surface pattern is formed; and a second region disposed on one side of the first region in which the emission surface pattern is formed, wherein the width of the emission surface pattern of the first region is formed to be smaller than the width of the emission surface pattern of the second region, and the width of the emission surface pattern in the second region may be provided to continuously increase in the direction toward the first light source unit.

[0162] The above-mentioned exit surface pattern is formed by injection molding using a mold, and the mold may be provided with a forming groove that is pressed by a pressing tool to form the exit surface pattern.

[0163] The above-mentioned pressing tool may be provided to continuously advance in the first direction with respect to the mold to create the forming groove, and to have a different depth of contact with the mold as it advances in the first direction.

[0164] The above pressing tool can contact the mold at a depth smaller than that at a position corresponding to the first region of the mold.

[0165] The above-mentioned pressing tool may be provided so that the depth of contact with the mold continuously increases as it advances from a position corresponding to the second region toward a direction corresponding to the first light source portion.

[0166] The light guide plate may include a lower surface pattern arranged to protrude toward the second light source unit on the lower surface; and a side surface pattern arranged to protrude toward the first light source unit on the side surface.

[0167] The above-mentioned pattern may be provided in a pyramid shape, and the area of ​​the first surface facing the first light source unit may be provided to be larger than the area of ​​the second surface facing the opposite direction of the first light source unit.

[0168] The above side patterns may be provided in multiple numbers, with the longitudinal direction arranged in the second direction and spaced apart from each other in a third direction intersecting the first direction and the second direction.

[0169] The above-mentioned side pattern may be formed in a semicircle or semi-ellipse shape in which a cross-section cut in the third direction protrudes in relief from the side of the light guide plate, and may be provided so that the width is constant in the second direction.

[0170] The display unit includes a public area in front of the display unit where all users can view the displayed image; and optionally, a variable private area where all users or only some users can view the displayed image, wherein the public area overlaps at least partly with the first area, and the variable private area overlaps at least partly with the second area.

[0171] When the first light source unit is turned on, the variable personal area may be provided so that all users can view the displayed image, and when the first light source unit is turned off, the variable personal area may be provided so that only some users can view the displayed image.

[0172] The above display unit may include a display panel on which an image is reproduced; a cover member disposed on an upper side of the display panel; and an optical sheet disposed on a lower side of the display panel and onto which light passing through the light guide plate is incident.

[0173] The display device may include a light control film disposed on the lower side of the light guide plate; an optical member disposed between the light control film and the second light source unit; and a reflector disposed on the lower side of the second light source unit.

[0174] Although the present specification has been described with reference to the drawings exemplified above, it is to be understood that the present specification is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical spirit of the present specification. Furthermore, even if the operational effects according to the configuration of the present specification have not been explicitly described while describing the embodiments of the present specification, it is natural that the effects predictable by the configuration should also be acknowledged.

Claims

1. Display section; A light guide plate disposed on the lower side of 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 positioned on the lower side of the light guide plate and irradiating light toward the light guide plate Including, The above light guide plate, It includes a plurality of emission surface patterns formed to protrude on the upper surface from which light is emitted, arranged in a first direction in the longitudinal direction, and arranged spaced apart from each other in a second direction intersecting the first direction, The above emission pattern is, It is provided so that the width increases in the direction toward the first light source unit. Display device.

2. In paragraph 1, The above emission pattern is, The cross-section cut in the second direction is formed in a semicircle or semi-ellipse shape that protrudes in relief from the upper surface of the light guide plate. Display device.

3. In paragraph 1, The above light guide plate, A first region in which the above emission pattern is formed; and A second region arranged on one side of the first region and in which the emission pattern is formed Including, The width of the emission surface pattern of the first region is formed to be smaller than the width of the emission surface pattern of the second region, In the second region, the emission pattern is provided such that the width continuously increases in the direction toward the first light source. Display device.

4. In paragraph 3, The above-mentioned injection pattern is formed by injection molding using a mold, The above mold is provided with a forming groove that is pressed by a pressing tool to form the above-mentioned exit surface pattern. Display device.

5. In paragraph 4, The above pressurizing tool is, The forming groove is formed by continuously advancing in the first direction with respect to the mold, and the depth of contact with the mold is provided to vary as it advances in the first direction. Display device.

6. In paragraph 5, The above pressurizing tool is, Contacting the mold at a position corresponding to the first region of the mold at a depth smaller than that corresponding to the second region, Display device.

7. In paragraph 6, The above pressurizing tool is, It is provided so that the depth of contact with the mold continuously increases as it progresses from a position corresponding to the second region toward a direction corresponding to the first light source section. Display device.

8. In paragraph 1, The above light guide plate, A lower pattern arranged to protrude toward the second light source unit on the lower surface; and A side pattern positioned to protrude toward the first light source portion on the side including, Display device.

9. In paragraph 8, The above pattern is, Equipped in a pyramid shape, The area of ​​the first surface facing the first light source unit is larger than the area of ​​the second surface facing the opposite direction of the first light source unit. Display device.

10. In paragraph 8, The above side pattern is, A plurality of longitudinally arranged members are arranged in the second direction and spaced apart from each other in a third direction intersecting the first direction and the second direction. Display device.

11. In paragraph 10, The above side pattern is, The cross-section cut in the third direction is formed into a semicircle or semi-ellipse that protrudes in relief from the side of the light guide plate, Equipped to have a constant width in the second direction, Display device.

12. In paragraph 3, The above display unit, A public area in front of the display unit where all users can view the displayed image; and A variable private area where images can be displayed to all or only some users, optionally Including, The above public area overlaps at least partly with the first area, The above variable personal area overlaps at least partly with the second area, Display device.

13. In paragraph 12, When the first light source is turned on, the variable personal area is provided so that all users can see the displayed image, and when the first light source is turned off, the variable personal area is provided so that only some users can see the displayed image. Display device.

14. In paragraph 1, The above display unit, A display panel on which images are played; A cover member arranged on the upper side of the display panel; and An optical sheet placed on the lower side of the display panel and onto which light passing through the light guide plate is incident. including, Display device.

15. In paragraph 1, A light control film disposed on the lower side of the light guide plate; An optical member disposed between the light control film and the second light source unit; and A reflector placed on the lower side of the second light source unit including, Display device.

Images