Double-compensation liquid crystal display panel with wide viewing angle and high contrast ratio

Abstract

The utility model relates to the technical field of display panels, and particularly discloses a wide-viewing-angle high-contrast double-compensation liquid crystal display panel which comprises a first polaroid, a first compensation film, a second compensation film, a first ITO (indium tin oxide) glass substrate, a liquid crystal box, a second ITO glass substrate and a second polaroid which are sequentially arranged from top to bottom. The attaching angle of the first compensation film and the first polaroid is 52 degrees, the attaching angle of the second compensation film and the first polaroid is 21 degrees, the liquid crystal twisting angle in the liquid crystal box is 250 degrees, and the liquid crystal gradient is 1.06. According to the display panel, a bottom polaroid is designed to be of a semi-transparent type; meanwhile, a compensation film is not used for the bottom polaroid, a double-compensation-film structural design is used for the face polaroid, the display mode of an existing DFSTN negative display product is changed, the whole DFSTN negative display product finished product is high in background color blackness, and the definition and the contrast ratio of the drive lightening display content are obviously improved.

Description

Technical Field

[0001] The utility model relates to the technical field of display panels, in particular to a double-compensation liquid crystal display panel with wide viewing angle and high contrast. Background Art

[0002] LCD screens include TN / HTN / STN / FSTN / FFSTN / DFSTN segment, dot-matrix LCDs (FULL DOT LCD), and VALCD. They are widely used in industrial control, instrumentation, POS terminals, blood pressure monitors, blood glucose meters, household appliances, and automotive instrumentation. Conventional black-and-white STN-type LCDs (STN-LCDs) typically use a compensation film and polarizer to create FSTN products that display black and white backgrounds and text. Depending on the application industry, FSTN products are generally designed as positive-mode FSTN (black text on a white background), while negative-mode DFSTN products are generally designed as fully transparent with surface film compensation.

[0003] At present, conventional negative display DFSTN products generally adopt a single-sided double compensation method, with a structure such as Figure 1 As shown, it includes a first polarizer 1, a first compensation film 2, a first ITO glass substrate 4, a liquid crystal box 5, a second ITO glass substrate 6, a third compensation film 9, and a second polarizer 7, which are arranged in sequence. The negative display DFSTN product is based on the liquid crystal distortion principle. The liquid crystal distortion angle is basically made into 240°, and the pre-tilt angle is 4-5° PI liquid. The surface and bottom are normally matched with polarizers with compensation values ​​of -60 / -30. Due to the limitations of the principle structure and its normal material and process combination, this type of negative display DFSTN product has problems such as insufficient background darkness, obvious ITO background shadow, and insufficient viewing angle range (obvious font color change in the upper and lower or left and right viewing angles). If the number of driving routes (DUTY number) is large, there will also be problems of low contrast and poor display font resolution.

[0004] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art. Utility Model Content

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a dual-compensation liquid crystal display panel with a wide viewing angle and high contrast, which innovatively changes the conventional DFSTN product (fully transparent type) into a semi-transparent type, significantly improving the clarity and contrast of the displayed content and significantly increasing the viewing angle range.

[0006] In order to achieve the above-mentioned objectives, the present invention provides a dual-compensation liquid crystal display panel with a wide viewing angle and high contrast, comprising a first polarizer, a first compensation film, a second compensation film, a first ITO glass substrate, a liquid crystal box, a second ITO glass substrate, and a second polarizer, which are arranged in sequence from top to bottom. The second polarizer is a semi-transmissive polarizer, the fitting angle between the first compensation film and the first polarizer is 52°, the fitting angle between the second compensation film and the first polarizer is 21°, the liquid crystal twist angle in the liquid crystal box is 250°, and the liquid crystal steepness is 1.06.

[0007] Furthermore, the liquid crystal cell is provided with PI alignment layers on both sides close to the first ITO glass substrate and the second ITO glass substrate, respectively, and the pre-tilt angle of the PI alignment layers is 6-7°.

[0008] Furthermore, the transmittance of the second polarizer is 16%.

[0009] Furthermore, one end of the first ITO glass substrate or the second ITO glass substrate is electrically connected to the PIN step.

[0010] The above solution of the utility model has the following beneficial effects:

[0011] The utility model provides a wide-viewing-angle, high-contrast dual-compensation liquid crystal display panel, in which the bottom polarizer is designed to be semi-transparent (with a transmittance of 16%, which is high polarization and low transmittance). Meanwhile, the bottom polarizer does not use a compensation film, but a dual-compensation film structure design is used on the face polarizer, thereby changing the display mode of the existing DFSTN negative display product. This makes the background color of the entire DFSTN negative display product high in blackness, and the clarity and contrast of the displayed content when driven to be lit are significantly improved compared with the ordinary double-sided single-compensation film.

[0012] The double compensation film angle design of the surface polarizer of the liquid crystal display panel of the utility model matches the refractive index of the liquid crystal. When used with the backlight, the display effect of the display panel can completely cover the ITO background and display wiring, and the entire display panel presents a completely black effect, and the overall comprehensive contrast is improved.

[0013] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of a single-sided double-compensation negative display DFSTN product in the prior art;

[0015] Figure 2 This is a schematic diagram of the overall structure of the dual-compensation liquid crystal display panel of the utility model;

[0016] Figure 3 Schematic diagram of the angle between the double compensation film and the first polarizer of the utility model.

[0017] [Description of Reference Numerals]

[0018] 1-first polarizer; 2-first compensation film; 3-second compensation film; 4-first ITO glass substrate; 5-liquid crystal cell; 6-second ITO glass substrate; 7-second polarizer; 8-PIN step; 9-third compensation film. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The various specific technical features and embodiments described in the specific embodiments can be combined in any suitable manner unless there is any contradiction. For example, different embodiments can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments in the present invention will not be described separately.

[0020] It should be noted that the terms "setting" and "connecting" should be understood in a broad sense. For example, they can be directly set, installed, and connected, or they can be indirectly set and connected through a central component or a central structural part. In addition, the orientations or positional relationships indicated by "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. in the present invention are based on the orientations or positional relationships shown in the drawings or the conventional placement state or usage state. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structural parts, features, devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0021] like Figures 2-3 As shown, this embodiment provides a dual-compensation liquid crystal display panel with wide viewing angle and high contrast, including a first polarizer 1, a first compensation film 2, a second compensation film 3, a first ITO glass substrate 4, a liquid crystal cell 5, a second ITO glass substrate 6, and a second polarizer 7, which are arranged in sequence from top to bottom. The second polarizer 7 is a semi-transmissive polarizer with a transmittance of 16%. The lamination angle between the first compensation film 2 and the first polarizer 1 is 52°, and the lamination angle between the second compensation film 3 and the first polarizer 1 is 21°. Key reference Figure 3 , the release film is upward, the θp axis is the light absorption axis of the first polarizer 1, θ r1 ,θ r2The axes are the slow axes of the first compensation film 2 and the second compensation film 3 respectively. In the conventional negative display DFSTN product in the prior art, the second polarizer 7 (called negative film in the industry) is made by compensating with the third compensation film 9 with a wavelength value of 430nm, which is called the single-sided double compensation method in the industry (such as Figure 1 As shown), in the wide viewing angle and high contrast dual-compensation liquid crystal display panel of the present invention, the second polarizer 7 is made into a semi-transparent type, and the first polarizer 1 (also known as the surface film in the industry) is added with a layer of compensation film, so that the background color of the entire finished product is high in blackness, and when used with a backlight, the ITO shadow is obviously blocked, and the clarity and contrast of the content displayed when driven are significantly improved compared with the ordinary double-sided single compensation film. Furthermore, the liquid crystal twist angle in the liquid crystal box is 250° and the liquid crystal steepness is 1.06. When developing liquid crystal, ensure that the liquid crystal steepness VON-VOFF is within 0.1V, so that the steepness of the product itself can be improved, thereby improving the contrast of the product as a whole. The display panel of the present invention widens the twist angle of the liquid crystal in the liquid crystal box 5, which can increase the viewing angle of the produced LCD. The friction angle of the front-stage process is made according to 250° during production, and the overall viewing angle width is significantly improved under the premise of improving the contrast.

[0022] Specifically, PI alignment layers are provided on both sides of the liquid crystal box 5 close to the first ITO glass substrate 4 and the second ITO glass substrate 6, respectively. The pretilt angle of the PI alignment layer is 6 to 7 degrees. That is, polyimide (PI liquid) with a pretilt angle of 6 to 7 degrees is used to apply the PI alignment layer on both sides of the liquid crystal box 5 close to the glass substrate. Specifically, after the polyimide film is coated to form the PI alignment layer, friction treatment is required, and the friction strength width is controlled between 17 and 18 mm.

[0023] Furthermore, an ITO conductive layer is provided on the side of the first ITO glass substrate 4 and the second ITO glass substrate 6 close to the liquid crystal box 5, and one end of either the first ITO glass substrate 4 or the second ITO glass substrate 6 is electrically connected to the PIN step 8, which is used to connect the external control circuit with the ITO conductive layer.

[0024] The backlight color and backlight brightness value selection of the display panel of the utility model: According to the black and white combination of the negative display DFSTN product, a cool white light is selected as the backlight, and the brightness value is 350~450cd / m 2 between.

[0025] The wide-viewing-angle and high-contrast dual-compensation liquid crystal display panel provided by the present invention has a significantly improved viewing angle range compared to ordinary DFSTN products currently on the market, with a vertical viewing angle width of approximately 30° and a horizontal viewing angle width of approximately 40°, as shown in Table 1 below.

[0026] Table 1 Comparison of viewing angle range (- indicates negative viewing angle)

[0027]

[0028] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A dual-compensation liquid crystal display panel with wide viewing angle and high contrast, characterized in that: The invention comprises a first polarizer (1), a first compensation film (2), a second compensation film (3), a first ITO glass substrate (4), a liquid crystal box (5), a second ITO glass substrate (6) and a second polarizer (7) which are arranged in sequence from top to bottom. The second polarizer (7) is a semi-transmissive polarizer. The lamination angle between the first compensation film (2) and the first polarizer (1) is 52°, the lamination angle between the second compensation film (3) and the first polarizer (1) is 21°, and the liquid crystal twist angle in the liquid crystal box (5) is 250° and the liquid crystal steepness is 1.

06.

2. The wide-viewing-angle and high-contrast dual-compensation liquid crystal display panel according to claim 1, characterized in that: The liquid crystal box (5) is provided with PI alignment layers on both sides close to the first ITO glass substrate (4) and the second ITO glass substrate (6), respectively, and the pre-tilt angle of the PI alignment layer is 6-7°.

3. The wide-viewing-angle and high-contrast dual-compensation liquid crystal display panel according to claim 1, characterized in that: The transmittance of the second polarizer (7) is 16%.

4. The wide-viewing-angle and high-contrast dual-compensation liquid crystal display panel according to claim 1, wherein: One end of the first ITO glass substrate (4) or the second ITO glass substrate (6) is electrically connected to the PIN step (8).

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