Patent ID: 12235472

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The same reference numbers may be used throughout the drawings to refer to the same or like parts.

FIG.1is a view illustrating a method of inspecting a display device by an inspection apparatus according to the present invention.

Referring toFIG.1, the inspection apparatus of the present invention may include a shooting member210shooting a display device100located therebelow, and a processing member220which processes the picture shot by the shooting member210and detects a defect such as an abnormality of brightness or stain.

The shooting member210may include a camera218, a lens system215, a focusing member (not shown), and so on. The camera218is a member shooting a picture displayed on the display device100therebelow. The camera218may include, but not limited to, a CCD (Charged Coupled Device) camera.

The lens system215may include one or more lens, and make a picture, which is displayed on the display device100, into parallel rays to be input to the camera218. The lens system215may include a filter.

The focusing member may move the lens system215and the camera218together to focus on the picture displayed on the display device100. The focusing member may include a fixing member to fix a lens and a moving member to move a lens vertically and/or horizontally.

The picture shot by the shooting member210is input to the processing member220. The processing member220may process a shot picture input thereto and generate an information of the shot picture, and then may compare the processed information with a set information and decide a good quality of a display device or compensate for a picture.

For example, the processed information may be a brightness information. The processed brightness information is compared with a stored brightness information to calculate a difference value. When the calculated difference value is equal to or greater than a first set value, it is decided that a display device is defective, and a manufactured display device is discarded or a defect of a manufactured display device is removed through a process such as a repair or the like.

When the difference value of the brightness information is equal to or greater than a second set value and is less than the first set value, a defect being able to be removed by compensating for a picture is decided, and the processing member220calculates a compensation value corresponding to the difference value and then outputs the compensation value to a control portion180.

The control portion180converts a picture data, which is supplied from an external system, based on the compensation value input from the processing portion220, and then supplies the converted data to a data driving portion (not shown). Further, the data driving portion converts the input picture data into an analog picture signal, and then supplies the analog picture signal to a data line to display a compensated picture.

The control portion180may be located inside or outside the display device100.

The inspection apparatus200for the display device100directly shoots a picture displayed on the display panel110, and then processes the shot picture. Accordingly, the inspection apparatus200decides a defect of the display device100and compensates for a picture to display a high-quality picture.

The inspection of the display device100may be conducted in various steps. For example, the inspection may be conducted after completing the display panel110, or may be conducted in a step of a display module in which a FPCB (Flexible Printed Circuit Board), which a data driving element and the control portion180are mounted on, and so on are attached to the display panel110.

The display device100as the inspected object may be one of various display devices such as a liquid crystal display device, an organic light emitting display device, an electrophoresis display device, a mini LED (Light emitting diode) display device, and a micro LED display device.

FIG.2is a view illustrating a display device as an object of an inspection apparatus according to a first embodiment of the present invention.

Referring toFIG.2, the display device100of the first embodiment may include a display panel110and a light path controlling member140located on the display panel110.

The display panel110may be, but not limited to, a liquid crystal panel, an organic light emitting display panel, an electrophoresis display panel, a mini LED display panel, or a micro LED display panel. However, the display panel110may be one of other known various display panels.

The display panel110may include a first substrate120, a second substrate130, and a display element125between the first and second substrates120and130. The first and second substrates120and130may be formed of a solid transparent material such as a glass, or a flexible transparent material such as a plastic.

Even though not shown in the drawings, a plurality of data lines and a plurality of gate lines, which are arranged in vertical and horizontal directions, respectively, to define a plurality of pixel regions, may be formed at the first substrate120. A thin film transistor as a switching element may be formed in each pixel region, and a pixel electrode may be formed on the pixel region.

The thin film transistor may include a gate electrode connected to the gate line, a semiconductor layer which is formed of an amorphous silicon, crystalline silicon or oxide semiconductor stacked on the gate electrode, and source and drain electrodes which are on the semiconductor layer and are connected to the data line and the pixel electrode, respectively.

In the case that the display panel110is an organic light emitting display panel, the display element125may include an organic light emitting element. The organic light emitting element may include a pixel electrode (i.e., a first electrode), an organic light emitting layer on the pixel electrode, and a second electrode on the organic light emitting layer. The first electrode may be an anode or cathode. The second electrode may be an anode or cathode.

In the case that the display panel110is a liquid crystal display panel, the display element125may include a liquid crystal layer. In the case that the display panel110is an electrophoresis display panel, the display element125may include an electrophoresis layer. In the case that the display panel110is a mini LED display panel or micro LED display panel, the display element125may include a mini LED or micro LED.

Further, in the case that the display panel110is an organic light emitting display panel, an encapsulation layer to prevent a penetration of an external moisture or substance may be formed on the organic light emitting element. The encapsulation layer may include at least one inorganic layer and at least one organic layer, for example, a stack structure of inorganic layer/organic layer or inorganic layer/organic layer/inorganic layer. The second substrate may be formed of a transparent film such as a PS (Polystyrene) film, PE (Polyethylene) film, PEN (Polyethylene Naphthalate) film, or PI (Polyimide) film.

In the case that the display panel110is a liquid crystal display panel, a color filter which has sub-color filters to display red (R), green (G) and blue (B), a black matrix which divides the sub-color filters and blocks a light passing through a liquid crystal layer, and a common electrode may be formed at the second substrate130. The color filter and the common electrode may be formed at the first substrate120.

The light path controlling member140may be, but not limited to, a transparent adhesive such as an OCA (Optically Clear Adhesive) or OCR (Optically Clear Resin). The light path controlling member140may be directly formed on a top surface of the display panel110.

Even though explained in detail below, when the display device100is shot and inspected by the shooting member210of the inspection apparatus200, the light path controlling member140prevents a moire from happening in a picture displayed on the display panel110and shot by a camera.

As described above, the inspection apparatus200for the display device100shoots a picture displayed on the display panel110and detects a defect such as a stain. Then, the inspection apparatus200decides a good quality of a picture according to an extent of a defect, or calculates a compensation value corresponding to the stain or the like and compensate for a picture to display a picture, in which the defect such as the stain is removed, on the display panel110.

However, when a picture displayed on the display panel110is shot by the camera, the picture shot by the camera is different from the picture displayed on the display panel110. In other words, pixel regions arranged periodically at the display panel110and optical sensors (i.e., camera sensors) arranged periodically at the camera periodically interferes with each other, and thus a moire, which has a high brightness region and a low brightness region produced alternately and periodically, happens in the shot picture.

Because good picture quality of the display device100is decided or a picture is compensated based on the shot picture having a moire, accurate decision of a good picture quality is impossible Further, a stain is not removed but is much produced in the compensated picture, or a moire having a high brightness and a low brightness alternated happens even in a displayed picture.

FIG.3is a view illustrating a moire happening in a picture shot by an inspection apparatus.

Referring toFIG.3, a plurality of pixel regions are formed in a lattice manner and arranged periodically and repeatedly in x and y directions. Sensors of a camera shooting a picture displayed on the display panel110are arranged repeatedly in x and y directions.

The display panel110displays a picture having brightnesses corresponding to picture signals at a plurality of pixel regions. In other words, a picture displayed on the display panel110has no defect such as a moire. However, in the case that a picture output from the display panel110is input to the camera of the shooting member210, when the picture output from the plurality of pixel regions of the display panel110having a periodicity is input to the camera sensors arranged periodically and repeatedly, a moire having a high brightness Bh and a low brightness Bl alternated and repeated happens by the pixel regions arranged periodically and the camera sensors arranged periodically, and the shot picture having the moire is recorded in the camera.

Thus, the processing portion220of the inspection apparatus200does not process a picture actually displayed on the display panel but processes the shot picture having the moire, and then performs a decision of good picture quality and a picture compensation. Accordingly, accurate decision of good picture quality and accurate compensation for the display device100are impossible.

The light path controlling member140prevents a moire from happening in a shot picture when the camera shooting a picture of the display panel110. Because the moire happening in the shot picture is caused by a periodic interference of the pixel regions of the display panel110and the camera sensors, the light path controlling member140removes the periodic interference between the pixel regions of the display panel110and the camera sensors and prevents the moire from happening.

FIGS.4A and4Bare a perspective view and a cross-sectional view schematically illustrating a light path controlling member according to the first embodiment of the present invention.

Referring toFIGS.4A and4B, the light path controlling member140may be formed in, but not limited to, an approximately quadrangular shape. The light path controlling member140may have other shape than the quadrangular shape. Because the light path controlling member140is attached to a front surface of the display panel110and transfers a picture output from the display panel110to the outside, the light path controlling member140may have the same shape as the display panel110.

For example, in the case that the display panel110has a rectangular shape, the light path controlling member140also has a rectangular shape. In the case that the display panel110has a square shape, the light path controlling member140also has a square shape.

Particularly, the display device100is recently formed to have various shapes because the display device100is applied to various fields such as a dashboard of an automotive. Accordingly, the light path controlling member140may have various shapes in accordance with various shapes of the display panel110.

The light path controlling member140may have a size a little bit greater than that of the display panel110so that the light path controlling member140may completely cover the display panel.110. Alternatively, the light path controlling member140may have the same size as the display panel110.

As shown in the drawings, the light path controlling member140is divided by a separation wall142so that the light path controlling member140includes a plurality of light path portions144which a picture output from the display panel110proceeds (or is transmitted by). The separation wall142reflects a picture proceeding along the light path portion144to always make the picture proceed in a certain direction through the light path portion144.

As shown in the drawings, a cross-sectional shape of the light path portion144defined by the separation wall142may be, but not limited to, a hexagonal shape. The cross-sectional shape of the light path portion144may be other various shapes such as a square shape, a rectangular shape, a circular shape and an elliptical shape. Particularly, the cross-sectional shape of the light path portion144may be varied as required. For example, the cross-sectional shape of the light path portion144may be formed to have a shape of the display panel or a shape of the pixel region.

The light path portion144may be formed of, but not limited to, an optical fiber of a glass such as a quartz or a polymeric material. The light path portion144may be formed of any material which transmits a light smoothly without loss. For example, a polymeric material, such as PMMA (Polymethyl Methacrylate), having a good light guiding property may be used for the light path portion144.

When a picture is delivered through the light path portion144, the separation wall142totally reflects a picture input from the light path portion144to the light path portion144to always make the picture output through the light path portion144. The separation wall142is made of a material having a refractive index less than that of the light path portion144, and due to the difference of refractive index, a light proceeding in the light path portion144is totally reflected by the separation wall142. The separation wall142may be formed of, but not limited to, a polymeric material having a refractive index less than that of the light path portion144.

Further, one light path portion144may be filled with one light guiding material, which is formed in a single body and has an area similar to a cross-sectional area of the light path portion144, for example, one optical fiber, or may be filled with a plurality of light guiding materials, for example, a plurality of optical fibers with no empty space.

FIG.5is a view illustrating a periodicity of a picture displayed on a display panel being lost when a light path controlling member being located in a display device according to the first embodiment of the present invention. For the purpose of explanations, a structure of a camera sensor215of a shooting member210is shown simply.

Referring toFIG.5, the light path controlling member140is located on a front surface of the display panel110and delivers a picture output from the display panel110to the outside. The camera sensors215are located over a front surface of the light path controlling member140and shoot a picture delivered by and input from the light path controlling member140.

A period Pd of the pixel region of the display panel110is almost similar to a period Pc of the camera sensor215. When a picture displayed on the display panel110is shot by the camera sensor215, an interference is caused by the pixel region and the camera sensor215having similar periods, and thus a moire happens in a shot picture.

However, a period Po of the light path controlling member140i.e., a period of the light path portion144of the light path controlling member140is much less than the period Pd of the pixel region and the period Pc of the camera sensor215(Po<Pd and Pc). For example, the period Pd of the pixel region of the display panel110may be tens of micrometers and the period Po of the light path portion144of the light path controlling member140may be a few micrometers, and thus the period Po of the light path controlling member140is a few times less than the period Pd of the pixel region of the display panel110.

The period Po of the light path controlling member140may be less than ½ of the period Pd of the pixel region and the period Pc of the camera sensor215(Po<Pd/2 or Po<Pc/2). Further, the period Po of the light path controlling member140may be greater than ⅕ of the period Pd of the pixel region and the period Pc of the camera sensor215(Pd/5<Po or Pc/5<Po). However, it is not limited, the period Po of the light path portion144of the light path controlling member140may be less than ⅕ of the period Pd of the pixel region and the period Pc of the camera sensor215(Po<Pd/5 or Po<Pc/5).

In the drawings, the period Po of the light path controlling member140is formed periodically all over the light path controlling member140, but it is not limited. The period Po of the light path controlling member140may be formed non-periodically.

Since the light path controlling member140having the period Po different from the period Pd of the pixel region of the display panel110and the period Pc of the camera sensor215is located on the front surface of the display panel110, a picture output from the display panel110is delivered through the light path portion144of the light path controlling member140. Because a picture output from one pixel region is transmitted through a plurality of light path portions144of the light path controlling member140, a periodicity of a light output from the pixel region arranged periodically in the display panel110is lost by the plurality of light path portions144.

As a result, a moire does not happen in a picture which is displayed from the display panel110, then is transmitted through the light path controlling member140, and then is input to and shot by the camera sensor215of the shooting member210, and thus an inspection defect due to a moire can be prevented.

As described above, in the display device100of this embodiment, the light path controlling member140is located on the front surface of the display panel110and a periodicity of a picture output from the display device100is lost. Accordingly, because an interference of a picture having a periodicity with the camera sensors215arranged periodically can be prevented, a moire happening in a shot picture can be prevented effectively.

FIG.6Ais a view illustrating a picture displayed on a display device in case of no light path controlling member being employed, andFIG.6Bis a view illustrating a picture displayed on a display device in case of a light path controlling member being employed according to the first embodiment of the present invention.FIG.7Ais a view illustrating a picture shot by a camera of an inspection apparatus for a picture displayed on a display device in case of no light path controlling member being employed, andFIG.7Bis a view illustrating a picture shot by a camera of an inspection apparatus for a picture displayed on a display device in case of a light path controlling member being employed according to the first embodiment of the present invention.

A picture displayed on the display device is a test picture. The test picture is shown in a rectangular shape in the drawings, but may be varied depending on a purpose of test.

A relation of the period Po of the light path portion144of the light path controlling member140of the display device100and a period Pd of the pixel region of the display panel110is Po=Pd/2.6.

Referring toFIG.6A, in the display device having no light path controlling member140, pictures of equal size are arranged regularly at equal periods. The period of the picture is equal to the period Pd of the pixel region of the display panel110.

In the display device having no light path controlling member140, because the pictures are arranged periodically, when the pictures are input to the shooting member210, the pictures arranged periodically interfere with the camera sensors215arranged periodically. Thus, as shown inFIG.7A, a high moire having a high brightness and low brightness arranged periodically happens in the shot picture.

Referring toFIG.6A, in the display device100of the first embodiment, because pictures are arranged at equal periods but have different sizes, distances between boundaries of actual pictures are not equal but different all over the screen. Accordingly, because a periodicity of the pictures displayed on the display device100, when the pictures are input to the shooting member210, an interference of the pictures with the camera sensors215arranged periodically is minimized. However, in the display device100of this embodiment, because the pictures are not displayed in a fully non-periodic or irregular manner, a moire is not removed fully from the shot picture but a low moire happens in the shot picture as shown inFIG.7B.

FIG.8is a view illustrating a structure of a display device according to a second embodiment of the present invention.

Referring toFIG.8, the display device300may include a display panel310and a light path controlling member340located on the display panel310.

The display panel310may be, but not limited to, a liquid crystal panel, an organic light emitting display panel, an electrophoresis display panel, a mini LED display panel, or a micro LED display panel. However, the display panel310may be one of other known various display panels.

Even though not shown in the drawings, the display panel310may include a first substrate, a second substrate, and a display element between the first and second substrates.

A plurality of pixel regions are arranged repeatedly and periodically in the display panel310. A plurality of light path portions344of the light path controlling member340are arranged non-periodically or irregularly.

In other words, while the light path portions144of the light path controlling member140of the first embodiment are arranged periodically, the light path portions344of the light path controlling member340of this embodiment are arranged non-periodically or irregularly.

As such, the light path portions344of the light path controlling member340of this embodiment being arranged non-periodically or irregularly is because of following reasons.

In the first embodiment, the light path portions144of the light path controlling member140of the first embodiment are arranged periodically, but the period Po of the light path portions144of the light path controlling member140is less than the period Pd of the pixel regions of the display panel110(Po<Pd). Thus, in the first embodiment, even though the light path portions144of the light path controlling member140of the first embodiment are arranged periodically, because of a difference of the period Po of the light path portions144of the light path controlling member140and the period Pd of the pixel regions of the display panel110, the periodicity of the picture output from the display panel110and delivered through the light path controlling member140is lost not fully but partially.

Thus, when shooting a picture output from the display device100of the first embodiment using the inspection apparatus200, a picture input to the inspection apparatus200and a camera sensor interferes with each other not fully but partially. While the display device100can reduce an interference compared with the case of no light path controlling member140being employed, a partial interference of a picture input to the inspection apparatus200with the camera sensor is produced and thus a moire of a shot picture cannot be removed fully.

However, in this embodiment, because the light path portions344of the light path controlling member340are arranged non-periodically or irregularly, a periodicity of a picture output from the display panel310and delivered through the light path controlling member340to the inspection apparatus is lost fully. Accordingly, a picture input to the inspection apparatus and the camera sensor do not fully interfere with each other, and thus a moire of a shot picture can be removed fully.

Particularly, in this embodiment, when the light path controlling member340is satisfied with following conditions, a periodicity of a picture output from the display panel310and delivered through the light path controlling member340to the inspection apparatus is lost fully.

POe=(1⁢/⁢k)×Pd.Condition⁢⁢1Pdk+0.1≤PO≤Pdk-0.1.Condition⁢⁢2

Po is an individual period of the light path portions344of the light path controlling member340, Poe is an average period of the light path portions344of the light path controlling member340, Pd is a period of the pixel regions of the display panel310, and k is a period ratio of the light path portions344of the light path controlling member340and the pixel regions of the display panel310, wherein 2.6≤k≤3.0.

In this embodiment, when a relation of the period Po of the light path portions344of the light path controlling member340and the period Pd of the pixel regions of the display panel310is Pd/3.1≤Po≤Pd/2.5, a periodicity of a picture displayed on the display device300is lost fully and thus a moire does not happen in a shot picture. In other words, in this embodiment, the light path portions344of the light path controlling member340are formed to be arranged non-periodically or irregularly along with satisfaction with the conditions 1 and 2, and thus a moire of a shot picture can be removed.

FIG.9Ais a view conceptually illustrating pictures displayed on a display device in case that a relation of a period of light path portions of a light path controlling member and a period of pixel regions of a display panel is Pd/3.1≤Po≤Pd/2.5 (i.e., 2.6≤k≤3.0),FIG.9Bis a view conceptually illustrating pictures displayed on a display device in case that a relation of a period of light path portions of a light path controlling member and a period of pixel regions of a display panel is Po<Pd/3.1, andFIG.9Cis a view conceptually illustrating pictures displayed on a display device in case that a relation of a period of light path portions of a light path controlling member and a period of pixel regions of a display panel is Pd/2.5<Po.

FIG.10Ais a view illustrating shot pictures input to camera sensors of an inspection apparatus in case that a relation of a period of light path portions of a light path controlling member and a period of pixel regions of a display panel is Pd/3.1≤Po≤Pd/2.5,

FIG.10Bis a view illustrating shot pictures input to camera sensors of an inspection apparatus in case that a relation of a period of light path portions of a light path controlling member and a period of pixel regions of a display panel is Po<Pd/3.1, andFIG.10Cis a view illustrating shot pictures input to camera sensors of an inspection apparatus in case that a relation of a period of light path portions of a light path controlling member and a period of pixel regions of a display panel is Pd/2.5<Po.

Referring toFIG.9A, in the case that a relation of a period Po of light path portions344of a light path controlling member340and a period Pd of pixel regions of a display panel310is Pd/3.1≤Po≤Pd/2.5, the pictures output from respective pixel regions are displayed different in size and in period.

In this case, a periodicity of the pictures displayed on the display device300is lost fully, and thus no moire happens in the shot picture as shown inFIG.10A. Accordingly, a decision of a good picture quality of the display device300and a picture compensation of the display device300by the inspection apparatus200can be performed without errors.

Referring toFIG.9B, in the case that a relation of a period Po of light path portions344of a light path controlling member340and a period Pd of pixel regions of a display panel310is Pd/2.5<Po, the pictures output from respective pixel regions are displayed different in size and in period.

However, regarding the pictures displayed on such the display device300, because of an interaction of the light path controlling member340and the display panel310, a moire happens in the shot picture as shown inFIG.10B. Particularly, in this case, because of an interaction of the light path controlling member340and the display panel310, a low-frequency moire happens in the shot picture. Because the low-frequency moire has a very high recognition degree, a decision of a good picture quality of the display device300and a picture compensation of the display device300by the inspection apparatus200have errors.

Referring toFIG.9C, in the case that a relation of a period Po of light path portions344of a light path controlling member340and a period Pd of pixel regions of a display panel310is Po<Pd/3.1, the pictures output from respective pixel regions are displayed different in size but equal in period.

Accordingly, because a periodicity of the pictures displayed on the display device300is lost partially, a moire happens in the shot picture as shown inFIG.10C, there is a limit to solving errors produced in a decision of a good picture quality of the display device300and a picture compensation of the display device300by the inspection apparatus200.

As such, in this embodiment, by making the period Po of the light path portions344of the light path controlling member340non-periodic or irregular, a periodicity of the pictures displayed on the display panel310is removed and a moire happening in the shot picture can be prevented. Particularly, in this embodiment, the period Pd of the pixel regions of the display panel310is made non-periodic or irregular in a range of Pd/3.1≤Po≤Pd/2.5, and thus a moire happening in the shot picture can be prevented. As a result, errors being produced in a decision of a good picture quality of the display device300and a picture compensation of the display device300by the inspection apparatus200can be prevented.

Further, in this embodiment, because the light path controlling member340is located on the front surface of the display panel310, a moire happening in the shot picture can be prevented, and further, a color uniformity of a picture according to a viewing direction can be improved, which is explained in detail as follows.

FIG.11Ais a view illustrating a color uniformity of a picture according to a viewing direction in a display device having no light path controlling member, andFIG.11Bis a view illustrating a color uniformity of a picture according to a viewing direction in a display device having a light path controlling member according to this embodiment of the present invention.

Referring toFIG.11A, in the case that no light path controlling member is located on the front surface of the display panel, regarding pictures output from the display panel, monochromatic lights of shorter wavelength have wider output angles which the monochromatic lights spread out at while monochromatic lights of longer wavelength have narrower output angles which the monochromatic lights spread out at.

Accordingly, the monochromatic light of red is output at a narrow angle while the monochromatic light of blue is output at a wide angle. Thus, in the case that a picture of a red light and a blue light is output, a color (i.e., a mixture of the red light and the blue light) of a picture recognized by a user is different depending on a viewing positon. In other words, in the display device having no light path controlling member340, because the same picture is recognized with different colors depending on viewing directions, it is problematic that a color uniformity being reduced.

Referring toFIG.11B, in the case of the display device300including the light path controlling member340located on the front surface of the display panel, the monochromatic lights from the display panel are output at different angles.

However, in this embodiment, because the picture i.e., the monochromatic lights from the display panel is transmitted and output through the light path portion344of the light path controlling member340, the output range of the monochromatic lights is limited by the width of the light path portion344. Accordingly, because all of the monochromatic lights having different wavelengths have limited output angles by the light path portion344of the light path controlling member340, all of the monochromatic lights having different wavelengths are output at the same range of output angle.

Accordingly, the same color is recognized in an output range of picture of the light path portions344, and thus a picture having a constant color uniformity can be recognized at all viewing directions.

FIG.12is a view schematically illustrating a display device according to a third embodiment of the present invention.

Referring toFIG.12, the display device400may include a display panel410displaying a picture and a light path controlling member440located in the display panel410.

The display panel410may include a first substrate420, a second substrate430, and a display element425between the first and second substrates420and430.

The display panel410may be, but not limited to, a liquid crystal panel, an organic light emitting display panel, an electrophoresis display panel, a mini LED display panel, or a micro LED display panel. However, the display panel410may be one of other known various display panels.

Because the light path controlling member440includes light path portions formed non-periodically, lights output from the display panel410is displayed with periodicity thereof lost. Accordingly, a moire does not happen in a shot picture when being shot by an inspection apparatus, and an error of inspection can be prevented. Further, a color uniformity according to a viewing direction can be improved.

The light path controlling member440may be attached onto a bottom surface of the second substrate430i.e., a surface of the second substrate430facing the first substrate420, and then may be coupled to the first substrate420, thereby manufacturing the display device400. Further, an insulating layer may be formed on display element425, then the light path controlling member440may be attached onto the insulating layer, and then the second substrate430may be coupled to the light path controlling member440, thereby manufacturing the display device400.

FIGS.13A and13Bare views schematically illustrating display devices according to a fourth embodiment of the present invention.

Referring toFIG.13A, in the display device500, a functional panel550may be located on the display panel510, and a light path controlling member540may be located between the display panel510and the functional panel550.

The light path controlling member540may include a plurality of light path portions transmitting a picture output from the display panel510, and the plurality of light path portions may be formed periodically or non-periodically over the light path controlling member540. Further, the light path portions may be arranged irregularly with the light path portions being satisfied with the above conditions 1 and 2.

As the functional panel550, various panels such as a FPR (Film Patterned Retarder) panel or parallax barrier panel for a 3D (three dimension), a touch panel to facilitate an information input, and a cover glass to protect the display panel510, may be used.

Even though not shown in the drawings, the function panel550may be attached onto a front surface using an adhesive.

Referring toFIG.13B, in the display device500, a functional panel550may be located on the display panel510, and a light path controlling member540may be located on the functional panel550.

The light path controlling member540may include a plurality of light path portions transmitting a picture output from the display panel510, and the plurality of light path portions may be formed periodically or non-periodically over the light path controlling member540. Further, the light path portions may be arranged irregularly with the light path portions being satisfied with the above conditions 1 and 2.

As the functional panel550, various panels such as a FPR (Film Patterned Retarder) panel or parallax barrier panel for a 3D (three dimension), a touch panel to facilitate an information input, and a cover glass to protect the display panel510, may be used.

According to the above embodiments of the present invention, by placing the light path controlling member on the front surface of the display device, a periodicity of a picture output from the display device is lost, and thus a moire happening in a shot picture when inspecting the display device can be prevented. As a result, errors being produced in a decision of a good picture quality and a picture compensation by the moire when inspecting the display device can be prevented.

Further, in the above embodiments, because monochromatic lights having different radiation angles have limited output angles by the light path controlling member, a color uniformity according to a viewing direction can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the display device of the present disclosure without departing from the technical idea or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.