Display module and head-mounted display device

Abstract

The embodiment of the invention provides a display module and head-mounted display equipment, and relates to the technical field of display modules. The display module comprises a lens and a display screen. The lens and the display screen are sequentially arranged in the optical axis direction, the display screen comprises a plurality of pixels and a driving circuit connected with the pixels, driving parameters of the driving circuit are determined according to target transmittance, and the target transmittance is determined according to the pixels connected with the driving circuit and the transmittance of a corresponding area in the lens. Therefore, the difference of the transmittances of different areas of the lens is made up in a targeted manner, so that the light-emitting parameters of the pixels in different areas are matched with the transmittances of the pixels in the corresponding areas of the lens. Thus, after the display module drives the corresponding pixels according to the determined driving parameters, the matching degree of the light emitting parameters of different areas of the display screen and the transmittance of the corresponding lenses is high, so that the display parameters (such as brightness and chromaticity) of the different areas of the display module are uniform, and the effect of optimizing the display uniformity of the display module is achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of display modules, and in particular to a display module and a head-mounted display device. Background Art

[0002] Display uniformity is an important specification of display modules, which is determined by the uniformity properties of the display screen and lens itself and the degree of matching between the two. Among them, the display module often has a higher brightness and whiter middle area, while the edge area has a lower brightness and yellowish color, resulting in poor display uniformity of the display module. Summary of the invention

[0003] The embodiments of the present application provide a display module and a head-mounted display device. After the corresponding pixels are driven according to the determined driving parameters, the luminous parameters of different areas of the display screen and the transmittance of the corresponding lenses are highly matched, so that the display parameters (such as brightness, chromaticity, etc.) of different areas of the display module are uniform, thereby achieving the effect of optimizing the display uniformity of the display screen itself.

[0004] In a first aspect, an embodiment of the present application provides a display module, including:

[0005] lenses; and

[0006] Display screen;

[0007] The lens and the display screen are arranged in sequence along the optical axis direction. The display screen includes a plurality of pixels and a driving circuit connected to the pixels. The driving parameters of the driving circuit are determined according to a target transmittance. The target transmittance is determined according to the transmittance of the pixels connected to the driving circuit and a corresponding area in the lens.

[0008] Optionally, when each of the pixels displays the same gray scale, a first difference in display brightness of light emitted by any two of the pixels after passing through the lens is less than a first preset threshold; and / or a second difference in display chromaticity of light emitted by any two of the pixels after passing through the lens is less than a second preset threshold.

[0009] Optionally, when each of the pixels displays the same gray scale, a driving current of the driving circuit and a target transmittance corresponding to the driving circuit are negatively correlated.

[0010] Optionally, the driving circuit includes a red driving circuit, a green driving circuit and a blue driving circuit, the target transmittance includes a target red light transmittance, a target green light transmittance and a target blue light transmittance, the driving parameters of the red driving circuit are determined according to the target red light transmittance, the driving parameters of the green driving circuit are determined according to the target green light transmittance, and the driving parameters of the blue driving circuit are determined according to the target blue light transmittance; the target red light transmittance is determined according to the red light transmittance of the pixel connected to the red light driving circuit and the corresponding area in the lens, the target green light transmittance is determined according to the green light transmittance of the pixel connected to the green light driving circuit and the corresponding area in the lens, and the target blue light transmittance is determined according to the blue light transmittance of the pixel connected to the blue light driving circuit and the corresponding area in the lens.

[0011] Optionally, the driving parameter includes a parameter affecting a driving current of the driving circuit.

[0012] Optionally, the driving circuit includes a driving transistor, and the driving parameters include at least one of a reset voltage of the driving circuit, a coupling capacitance, a channel width of the driving transistor, a channel length of the driving transistor, a carrier mobility of the driving transistor and an intrinsic capacitance of the driving transistor.

[0013] Optionally, the driving circuit includes a driving transistor, the driving parameters include a channel width of the driving transistor and a channel length of the driving transistor, a third ratio between a first ratio of the channel width and the channel length and a preset second ratio is equal to the inverse of the corresponding target transmittance, and the second ratio is the ratio of the channel width and the channel length of the driving transistor whose target transmittance is a preset value.

[0014] Optionally, the corresponding area of ​​the pixel in the lens includes at least an area of ​​the lens directly opposite to the pixel.

[0015] Optionally, the lens includes a plurality of lens areas, different lens areas have different transmittances, and the target transmittance is determined according to the transmittance of the lens area corresponding to the pixel connected to the driving circuit in the lens.

[0016] In a second aspect, an embodiment of the present application provides a head mounted display device, comprising:

[0017] framework; and

[0018] In the display module described in any one of the embodiments of the first aspect, the display module is arranged on the frame.

[0019] In summary, in the embodiment of the present application, the display module determines the target transmittance according to the transmittance of the corresponding area in the lens of the pixels connected to the driving circuit, and then determines the driving parameters of the driving circuit according to the target transmittance, so as to specifically compensate for the difference in transmittance of different areas of the lens, so that the luminous parameters of the pixels in different areas match the transmittance of the pixels in the corresponding area of ​​the lens. In this way, after the display module drives the corresponding pixels according to the determined driving parameters, the luminous parameters of different areas of the display screen and the transmittance of the corresponding lens have a high degree of matching, so that the display parameters (such as brightness, chromaticity, etc.) of different areas of the display module are uniform, so as to achieve the effect of optimizing the display uniformity of the display module itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic diagram of the structure of a display module provided in an embodiment of the present application;

[0022] Figure 2 A schematic diagram of a driving circuit provided in an embodiment of the present application;

[0023] Figure 3 A target transmittance distribution diagram of a lens provided in an embodiment of the present application;

[0024] Figure 4 A target transmittance distribution diagram of another lens provided in an embodiment of the present application;

[0025] Figure 5 A distribution diagram of the channel width and channel length of a driving transistor of a driving circuit provided in an embodiment of the present application;

[0026] Figure 6 A distribution diagram of the channel width and channel length of a driving transistor of another driving circuit provided in an embodiment of the present application;

[0027] Figure 7 A distribution diagram of the channel width and channel length of a driving transistor of another driving circuit provided in an embodiment of the present application;

[0028] Figure 8 A schematic diagram of the structure of a display module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one feature. In the description of this application, the meaning of "plurality" is at least two, such as two, three, unless otherwise clearly and specifically defined.

[0032] The technical solution of this application will be described in detail below:

[0033] Figure 1 A schematic diagram of the structure of a display module 100 provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the display module 100 may include a lens 10 and a display screen 20. The lens 10 and the display screen 20 are sequentially arranged along the optical axis direction, and the display screen 20 includes a plurality of pixels 21 and a driving circuit 22 connected to the pixels 21. The driving parameters of the driving circuit 22 are determined according to the target transmittance, and the target transmittance is determined according to the transmittance of the corresponding area in the lens 10 of the pixels 21 connected to the driving circuit 22.

[0034] Specifically, augmented reality (AR), virtual reality (VR), and mixed reality (MR) are carriers for the fusion of the real world and the virtual world. Real scenes can be combined with virtual scenes through computers to create a virtual environment that can interact with humans and machines. Through extended reality devices (such as VR glasses), virtual content and real scenes can be integrated, and there is a sense of "immersion" with seamless transitions between the virtual world and the real world. Therefore, AR, VR, and MR are becoming hot topics in the field of consumer electronics. The lens 10 and the display screen 20 are arranged in sequence along the optical axis direction, and the light emitted by the display screen 20 reaches the user's eyes through the lens 10 to combine the real scene with the virtual scene displayed by the display screen 20.

[0035] The display module 100 is mainly composed of a display screen 20 and a lens 10. Optical solutions corresponding to the display module 100 include a folded light path solution (Pancake), an optical waveguide, a coaxial air-guided light imaging solution (Birdbath), Fresnel, a free-form surface, and the like.

[0036] The image on the display screen 20 is composed of many points, which are called pixels 21. The pixels 21 of the display screen 20 are provided with power and switching signals by the driving circuit 22. The driving circuit 22 includes a driving transistor. The driving circuit 22 operates according to the corresponding driving parameters so that the pixels 21 can emit light of different brightnesses, wherein the driving parameters are parameters that affect the luminous parameters (such as luminous brightness and / or luminous chromaticity). For example, the magnitude of the driving current affects the luminous parameters, and the driving parameters can be parameters that affect the driving current of the driving circuit 22. The display module 100 only needs to determine the relationship between the driving parameters and the luminous parameters, and can adjust the driving parameters according to the target transmittance, so that the display parameters of different areas are uniform.

[0037] For example, Figure 2 It is an organic light-emitting diode (OLED) 2T1C pixel 21 driving circuit 22. Among them, Figure 2ELVDD is the positive power supply voltage of the pixel 21, ELVSS is the negative power supply voltage, OLED is the display light emitting device, Data is the data signal of the pixel 21, Scan is the row scanning signal of the pixel 21, T1 is the switching metal-oxide-semiconductor field-effect transistor (MOSFET or MOS), T2 is the driving transistor, and Cst is the storage capacitor. For the current display screen 20, the driving parameters of the driving circuit 22 of each pixel 21 are all consistent. In this way, under the same set of gamma bands, when displaying the same grayscale, the Data voltage value of the driving current of each pixel 21 is consistent, and the current output by the driving transistor T2 and flowing through the OLED is also consistent.

[0038] The lens 10 is an optical element made of a light-transmitting material (such as glass, plastic or crystal, etc.), and mainly uses the refraction of light to transmit light in the optical path of the display module 100. Generally speaking, the lens 10 will show the characteristics of high transmittance in the middle area and low transmittance at the edge, and this characteristic is particularly obvious in the blue light band, that is, the difference between the transmittance of blue light in the middle area and the transmittance in the edge area will be greater, for example Figure 3 As shown, Figure 3 The darker the color, the higher the transmittance. At the same time, the driving parameters of the pixels 21 in different areas of the current display screen 20 are the same, which causes the display parameters of the current display module 100 to be more affected by the transmittance of the lens 10, and further causes the current display module 100 to often have a higher brightness and whiter middle area, while the edge area has a lower brightness and yellower phenomenon, making the display uniformity of the current display module 100 poor, that is, the display parameters are uneven.

[0039] Display parameters include display brightness and display chromaticity. Display parameter uniformity of each area of ​​the display module 100 means that when each pixel 21 displays the same gray scale, a first difference in display brightness of light emitted by any two pixels 21 among the pixels 21 after passing through the lens 10 is less than a first preset threshold; or a second difference in display chromaticity of light emitted by any two pixels 21 among the pixels 21 after passing through the lens 10 is less than a second preset threshold; or while the first difference is less than the first preset threshold, the second difference is also less than the second preset threshold, that is, display parameter uniformity means that when each pixel 21 displays the same gray scale, the display brightness and / or display chromaticity of light emitted by each pixel 21 after passing through the lens 10 are basically the same, even if there is a difference in display brightness and / or display chromaticity between any two pixels 21, the difference will not be too large, and will not reduce the display uniformity of the display module 100. Among them, the first preset threshold is the upper limit of the difference in the reasonable range of the first difference. The first preset threshold can reflect the limit of the first difference when the display brightness of any two pixels 21 in each pixel 21 is basically the same. Once the first difference is greater than the first preset threshold, it means that the display brightness difference between the two pixels 21 is large, which may cause the display uniformity of the display module 100 to be poor. In one example, the first preset threshold can be an empirical value set manually. At this time, the first preset threshold can remain fixed or be changed by manual input. In another example, the first preset threshold can also be an empirical value analyzed based on parameters such as the historical display brightness when the display module 100 is working. Similarly, the second preset threshold is the upper limit of the difference in the reasonable range of the second difference. The second preset threshold can reflect the limit of the second difference when the display chromaticity of any two pixels 21 in each pixel 21 is basically the same. Once the second difference is greater than the second preset threshold, it means that the display chromaticity difference between the two pixels 21 is large, which may cause the display uniformity of the display module 100 to be poor. In one example, the second preset threshold may be an empirical value set manually, in which case the second preset threshold may remain fixed or may be changed by manual input. In another example, the second preset threshold may also be an empirical value analyzed based on historical display chromaticity and other parameters when the display module 100 is working.

[0040] Therefore, the display module 100 can determine the target transmittance according to the transmittance of the corresponding area of ​​the pixel 21 connected to the driving circuit 22 in the lens 10, for example, the transmittance of the area directly facing the pixel 21 can be directly used as the target transmittance, or the weighted average or arithmetic average of the transmittance of the area directly facing the pixel 21 and the transmittance of the area obliquely facing the pixel 21 (for example, the area with an angle less than 15 degrees with the pixel 21) can be used as the target transmittance. Among them, since the transmittance of the area directly facing the pixel 21 has a greater impact, the corresponding area of ​​the pixel 21 in the lens 10 at least includes the area directly facing the pixel 21 in the lens 10.

[0041] Then the display module 100 determines the driving parameters of the driving circuit 22 according to the target transmittance. At this time, it is necessary to confirm the relationship between the driving parameters and the luminous parameters, and then determine the driving parameters according to the condition that the luminous parameters are negatively correlated with the target transmittance. It can be understood that if the display parameters of different areas of the display module 100 are uniform, the display module 100 needs to make the luminous parameters of the pixels 21 corresponding to the area with higher target transmittance lower, and make the luminous parameters of the pixels 21 corresponding to the area with lower target transmittance higher. Alternatively, the luminous parameters of a certain area are used as the standard value, so that the luminous parameters of other areas are close to the standard value. In this way, the display module 100 determines the appropriate driving parameters according to the target transmittance, optimizes the distribution of the luminous parameters of the display screen 20 itself, is enough to make up for the difference in the target transmittance of different areas of the lens 10, offset the problem that the transmittance of the middle area of ​​the lens 10 is higher and the transmittance of the edge area is lower, so that the display parameters of different areas of the display module 100 are uniform, that is, the brightness and chromaticity uniformity of the display module 100 is improved.

[0042] The display module 100 of the embodiment of the present application determines the target transmittance according to the transmittance of the corresponding area in the lens 10 of the pixel 21 connected to the driving circuit 22, and then determines the driving parameters of the driving circuit 22 according to the target transmittance, so as to compensate for the difference in transmittance of different areas of the lens 10 in a targeted manner, so that the luminous parameters of the pixels 21 in different areas match the transmittance of the corresponding area of ​​the pixel 21 in the lens 10. In this way, after the display module 100 drives the corresponding pixel 21 according to the determined driving parameters, the distribution of the luminous parameters of the display screen 20 itself can be optimized, and the luminous parameters of different areas of the display screen 20 and the corresponding transmittance of the lens 10 have a high degree of matching, so that the display parameters (such as brightness, chromaticity, etc.) of different areas of the display module 100 are uniform, so as to achieve the effect of optimizing the display uniformity of the display module 100 itself.

[0043] See also Figure 1 Optionally, when each pixel 21 displays the same gray scale, the driving current of the driving circuit 22 and the target transmittance corresponding to the driving circuit 22 are negatively correlated.

[0044] Specifically, the larger the driving current, the higher the luminous parameter, and the smaller the driving current, the smaller the luminous parameter. Therefore, when each pixel 21 displays the same grayscale, the driving current of the driving circuit 22 and the target transmittance corresponding to the driving circuit 22 are negatively correlated, that is, the larger the target transmittance, the smaller the driving current, and the smaller the target transmittance, the larger the driving current. In this way, the magnitude of the driving current is determined according to the relationship between the driving current and the target transmittance, and after the pixel 21 is driven to emit light according to the driving current, under the same grayscale screen, the display module 100 can obtain different brightness in different areas of the display screen 20 to match the brightness transmittance difference of the lens 10, thereby ensuring the uniformity of the display parameters of different areas of the display module 100.

[0045] See also Figure 1 Optionally, the driving circuit 22 includes a red driving circuit 22, a green driving circuit 22 and a blue driving circuit 22, the target transmittance includes a target red light transmittance, a target green light transmittance and a target blue light transmittance, the driving parameters of the red driving circuit 22 are determined according to the target red light transmittance, the driving parameters of the green driving circuit 22 are determined according to the target green light transmittance, and the driving parameters of the blue driving circuit 22 are determined according to the target blue light transmittance; the target red light transmittance is determined according to the red light transmittance of the pixel 21 connected to the red light driving circuit 22 in the corresponding area of ​​the lens 10, the target green light transmittance is determined according to the green light transmittance of the pixel 21 connected to the green light driving circuit 22 in the corresponding area of ​​the lens 10, and the target blue light transmittance is determined according to the blue light transmittance of the pixel 21 connected to the blue light driving circuit 22 in the corresponding area of ​​the lens 10.

[0046] Specifically, the pixel 21 may include a red sub-pixel 21, a blue sub-pixel 21, and a green sub-pixel 21. Correspondingly, the driving circuit 22 includes a red driving circuit 22, a blue driving circuit 22, and a green driving circuit 22. The red sub-pixel 21 is connected to the red driving circuit 22, the blue sub-pixel 21 is connected to the blue driving circuit 22, and the green sub-pixel 21 is connected to the green driving circuit 22.

[0047] The transmittances of red light, green light and blue light in the same area of ​​the lens 10 may also be different. For example, the transmittance of blue light in the edge area is lower than the transmittances of red light and green light in the edge area, making the edge area of ​​the lens 10 prone to yellowing.

[0048] Therefore, the display module 100 can determine the target red transmittance according to the red transmittance of the corresponding area of ​​the red sub-pixel 21 in the lens 10, determine the target blue transmittance according to the blue transmittance of the corresponding area of ​​the blue sub-pixel 21 in the lens 10, and determine the target green transmittance according to the green transmittance of the corresponding area of ​​the green sub-pixel 21 in the lens 10. Then the display module 100 determines the driving parameters of the corresponding red driving circuit 22 according to the target red transmittance, determines the driving parameters of the corresponding blue driving circuit 22 according to the target blue transmittance, and determines the driving parameters of the corresponding green driving circuit 22 according to the target green transmittance, so as to adaptively adjust the light emitting parameters of the display screen 20, thereby optimizing the display uniformity of the display module 100.

[0049] For example Figure 4 , the red light transmittance, green light transmittance and blue light transmittance of the edge area are 60%, 80% and 40% respectively, then the display module 100 can make the driving parameters of the red driving circuit 22, the driving parameters of the green driving circuit 22 and the driving parameters of the blue driving circuit 22 have a ratio of 167%:125%:250%. After superimposing the display screen 20 and the lens 10, the display brightness and display chromaticity of different areas of the display module 100 are similar or even the same.

[0050] In this way, the display module 100 can also adjust the driving parameters of the driving circuit 22 of the three sub-pixels 21 within each area of ​​the display screen 20. After driving the pixels 21 to emit light according to the corresponding driving parameters, the chromaticity and brightness of the corresponding area can be changed, so that the display chromaticity and display chromaticity of different areas of the display module 100 can be compensated accordingly, making the display parameters of different areas of the display module 100 uniform.

[0051] Optionally, see Figure 1 The driving parameters include parameters that affect the driving current of the driving circuit 22.

[0052] Specifically, the magnitude of the driving current affects the light-emitting parameters, so the driving parameters may include parameters that affect the driving current. The parameters of the driving current may refer to the formula:

[0053] I=μCW / Lf(ELVDD - Vgs - Vth) (1)

[0054] Among them, μ is the carrier mobility of the driving transistor, C is the intrinsic capacitance of the driving transistor, W is the channel width of the driving transistor, L is the channel length of the driving transistor, and f(ELVDD-Vgs-Vth) is a function determined according to the working range (saturation region, subthreshold region) of the driving transistor. In a more complex driving circuit 22, the driving current may also be affected by the reset voltage and coupling capacitance. Therefore, the driving parameters include at least one of the reset voltage of the driving circuit 22, the coupling capacitance, the channel width of the driving transistor, the channel length of the driving transistor, the carrier mobility of the driving transistor, and the intrinsic capacitance of the driving transistor. The display module 100 only needs to determine the relationship between these driving parameters and the driving current, and can adjust the driving parameters according to the target transmittance to adjust the driving current accordingly, thereby adjusting the luminous parameters of the display screen 20, and then improving the display uniformity of the display module 100.

[0055] Optionally, see Figure 1 and Figure 2 The driving circuit 22 includes a driving transistor, the driving parameters include a channel width of the driving transistor and a channel length of the driving transistor, a third ratio between a first ratio of the channel width and the channel length and a preset second ratio is equal to the inverse of the corresponding target transmittance, and the second ratio is a ratio of the channel width to the channel length of the driving transistor whose target transmittance is a preset value.

[0056] Specifically, when determining the driving parameters, the display module 100 may first select a driving transistor with a target transmittance of a preset value (for example, 100%) as a reference driving transistor, and use the driving parameters corresponding to the reference driving transistor as the reference value. For example, the preset value is set to 100%, and the transmittance of the driving transistor corresponding to the central area is 100%. Then, the driving transistor corresponding to the central area of ​​the lens 10 may be used as the reference driving transistor, and the driving parameters of the reference driving transistor may be used as the reference value. Then, when the display parameters of the display module 100 are uniform, the ratio between the driving parameters corresponding to the reference driving transistor and the driving parameters corresponding to other driving transistors is calculated, so that the display module 100 can obtain the driving parameters corresponding to other driving transistors. It can be understood that when the display module 100 drives the display screen 20 according to the determined driving parameters, the display uniformity of the display module 100 is high.

[0057] As can be seen from the above formula (1), the first ratio of the channel width and the channel length of the driving transistor affects the magnitude of the driving current. The display module 100 can use the ratio of the channel width and the channel length of the driving transistor (for example, the driving transistor corresponding to the pixel 21 corresponding to the central area) with a target transmittance of a preset value as the second ratio, and use the second ratio as the reference value. Then the display module 100 calculates the first ratio according to the formula that the third ratio between the first ratio and the preset second ratio is equal to the inverse of the corresponding target transmittance, that is, according to the formula of first ratio / second ratio=1 / target transmittance. When producing the display module 100, the production equipment can produce the corresponding driving transistor according to the first ratio, so that the corresponding pixel 21 can emit the required brightness, make up for the brightness transmittance difference of the lens 10, and thus ensure the display uniformity of the display module 100.

[0058] For example, please combine Figure 3 The lens 10 includes a plurality of lens areas, and different lens areas have different transmittances. The target transmittance is determined according to the transmittance of the lens area relative to the pixel 21 connected to the drive circuit 22 in the lens 10. The transmittance of the lens area is negatively correlated with the distribution distance, wherein the distribution distance is the distance between the lens area and the center of the lens 10, that is, the transmittance of the lens 10 gradually decreases from the center to the edge of the lens 10. For example, the display module 100 can be divided into three areas according to the size of the transmittance, and the lens 10 is divided into a central area, a peripheral area, and an edge area. The target transmittance of the central area is 100%, the target transmittance of the peripheral area is attenuated to 80%, and the target transmittance of the edge area is attenuated to 50%.

[0059] The driving circuit 22 of the ordinary display screen 20 adopts the same structure, that is, the ratio of the channel width to the channel length of the driving transistors of all pixels 21 is the same, so that the display parameters of the three areas of the display module 100 are inconsistent. Figure 5, and the display module 100 of the present application uses the ratio of the channel width and channel length of the driving transistor of the driving transistor in the central area (1*W / L) as the second ratio, and then according to the formula of first ratio / second ratio=1 / target transmittance, the third ratio corresponding to the peripheral area is calculated to be 1.25, at which time the ratio of the channel width and channel length of the driving transistor in the peripheral area is 1.25W / L; the third ratio corresponding to the edge area is 2, at which time the ratio of the channel width and channel length of the driving transistor in the edge area is 2W / L. This means that, under the same driving voltage, the brightness of the peripheral area and the edge area of ​​the display screen 20 of the present application is 1.25 times and 2 times that of the central area, respectively. In this way, superimposed with the influence of the target transmittance, the brightness of the central area of ​​the display module 100 is 100%*1*W / L, the brightness of the peripheral area is 80%*1.25*W / L=100%*1*W / L, and the brightness of the central area is 50%*2*W / L=100%*1*W / L. It can be seen that the brightness of the three areas is completely equal, and the brightness uniformity of the display module 100 is well compensated.

[0060] The division of the lens area can be more detailed, for example, the number of lens areas can be 5, 10 or even smooth transition (smooth continuous gradient). Correspondingly, the driving parameters of multiple areas of the display screen can also be smoothly transitioned. The schematic diagram of the smooth transition is shown in FIG. Figure 6 As shown, Figure 6 Different colors represent different luminous parameters. The darker the color, the greater the luminous parameter. The key to smooth transition lies in the positioning of the pixel 21 and the adjustment of the channel width and channel length of the driving transistor. The production equipment can be operated by scripting language combined with electronic design automation (EDA) and other methods to form a complete mapping relationship between the thin film field effect transistor (TFT) exposure photolithography mask, light extraction structure mask or lens surface, and then adjust the channel width and channel length of the driving transistor accordingly to achieve the purpose of smooth transition, thereby ensuring the display uniformity of the display module 100.

[0061] When other driving parameters, such as carrier mobility or intrinsic capacitance, are used to adjust the driving current, the display module 100 can also adjust the driving parameters corresponding to different areas in a targeted manner according to the target transmittance of different areas and the relationship between the driving parameters and the driving current, so that the light emitted by the display screen 20 at different positions can make up for the target transmittance difference of different areas of the lens 10, thereby ensuring that the display parameters at different positions of the display module 100 are uniform. The specific implementation process can refer to the above method, and for the sake of brevity, it will not be repeated here.

[0062] In this way, the display module 100 can adjust the structure or parameters of the driving circuit 22 in different areas of the display screen 20, such as adjusting the first ratio of the channel width and channel length, the carrier mobility or the intrinsic capacitance of the driving transistor, so that different areas of the display screen 20 have different circuit structures and parameters. Therefore, under the same grayscale picture, the display module 100 can obtain different brightness in different areas to match the brightness transmittance difference of the lens 10, thereby ensuring the display uniformity of the display module 100.

[0063] Of course, the display module 100 can also use the above method when adjusting the driving parameters of the red driving circuit 22, the driving parameters of the green driving circuit 22, and the driving parameters of the blue driving circuit 22. It only needs to refine the preset driving transistors in the above method into driving transistors of the red driving circuit 22, driving transistors of the green driving circuit 22, and driving transistors of the blue driving circuit 22, and then obtain the second ratio and target transmittance of the driving circuits 22 of different colors, and perform corresponding calculations to achieve compensation for the display chromaticity and display brightness of different areas of the display module 100. In this way, the display module 100 can also adjust the structure and parameters of the driving circuits 22 of the three sub-pixels 21 in each area of ​​the display screen 20, adjust the relative size of the driving currents of the three sub-pixels 21, thereby changing the display chromaticity and display brightness, and ensuring that the display parameters of different areas of the display module 100 are uniform.

[0064] For example, please combine Figure 4 , assuming that the target red transmittance, target green transmittance and target blue transmittance of the central area of ​​the lens 10 are 100%, 100% and 100% respectively, the target red transmittance, target green transmittance and target blue transmittance of the peripheral area of ​​the lens 10 (i.e., the area between the central area and the edge area) are 80%, 90% and 60% respectively, and the target red transmittance, target green transmittance and target blue transmittance of the edge area of ​​the lens 10 are 60%, 80% and 40% respectively.

[0065] Please combine Figure 7, the display module 100 can determine the driving parameters of different driving circuits 22 according to the algorithm of first ratio / second ratio=1 / target transmittance. The display module 100 can use the ratio of the channel width and channel length of the driving transistor of the driving transistor in the central area as the second ratio, and at this time, the driving parameters of the red driving circuit 22 in the central area of ​​the lens 10, the driving parameters of the green driving circuit 22, and the second ratio of the blue driving circuit 22 are all 100%*W / L. After calculation, it can be known that the first ratio of the red driving circuit 22 in the peripheral area of ​​the lens 10 is 125%*W / L, the first ratio of the green driving circuit 22 is 111%*W / L, and the first ratio of the blue driving circuit 22 is 167%*W / L; the first ratio of the red driving circuit 22 in the edge area of ​​the lens 10 is 167%*W / L, the first ratio of the green driving circuit 22 is 125%*W / L, and the first ratio of the blue driving circuit 22 is 250%*W / L. In this way, the closer to the edge of the display screen 20, the larger the first ratio of the blue driving circuit 22, wherein the first ratio of the blue driving circuit 22 is particularly large, greater than the first ratio of the green driving circuit 22 and the first ratio of the red driving circuit 22, so that the closer to the edge of the display screen 20, the brighter and bluer the display screen 20 is, thereby offsetting the problem that the transmittance in the middle of the lens 10 is high and whitish, and the transmittance at the edge is low and yellowish. In this way, when the display screen 20 and the lens 10 form a display module 100, the brightness of the red light, green light and blue light in the three regions of the display module 100 is the same, and it can be seen that the brightness and chromaticity uniformity of different regions of the display module 100 are compensated.

[0066] Figure 8 is a schematic block diagram of a head mounted display device 1000 provided in an embodiment of the present application. Figure 8 As shown, the head mounted display device 1000 may include: a frame 200 and a display module 100 in any embodiment of the present application. The display module 100 is disposed on the frame 200 .

[0067] Specifically, the head-mounted display device 1000, such as AR glasses, VR glasses, and MR glasses, can be used as an extended reality device to integrate virtual content and real scenes, and provide a sense of "immersion" with seamless transition between the virtual world and the real world. After the user wears the head-mounted display device 1000, the light emitted by the display screen 20 will pass through the lens 10 to reach the user's head-mounted display device 1000. The display effect of the superposition of the light-emitting parameters of the display screen 20 and the transmittance of the lens 10, that is, the display parameters of the display module 100, will affect the user's experience.

[0068] The display module 100 can determine the driving parameters of the corresponding driving circuit 22 according to the target transmittance of different areas and the relationship between the driving parameters and the luminous parameters. For areas with smaller target transmittance, the display module 100 can make the luminous parameters of the pixels 21 corresponding to the area larger, and for areas with larger target transmittance, the display module 100 can make the luminous parameters of the pixels 21 corresponding to the area smaller. In this way, the display module 100 can make up for the difference in target transmittance of different areas of the lens 10, so that the display parameters of different areas of the display module 100 are uniform. Therefore, as long as the display module 100 obtains the target transmittance of the pixel 21 in the corresponding area of ​​the lens 10 and adjusts the driving parameters accordingly according to the target transmittance, it can ensure that the display parameters of different areas of the display module 100 are uniform.

[0069] The head mounted display device 1000 of the embodiment of the present application determines the target transmittance according to the transmittance of the corresponding area in the lens 10 of the pixel 21 connected to the driving circuit 22, and then determines the driving parameters of the driving circuit 22 according to the target transmittance, so as to compensate for the difference in transmittance of different areas of the lens 10 in a targeted manner, so that the luminous parameters of the pixels 21 in different areas match the transmittance of the corresponding area of ​​the pixel 21 in the lens 10. In this way, after the head mounted display device 1000 drives the corresponding pixels 21 according to the determined driving parameters, the distribution of the luminous parameters of the display screen 20 itself can be optimized, and the luminous parameters of different areas of the display screen 20 and the corresponding transmittance of the lens 10 have a high degree of matching, so that the display parameters (such as brightness, chromaticity, etc.) of different areas of the display module 100 are uniform, so as to achieve the effect of optimizing the display uniformity of the display module 100 itself.

[0070] In the description of this specification, the description with reference to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, unless otherwise clearly and specifically defined.

[0072] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A display module, characterized in that: include: lens; and Display screen; The lens and the display screen are arranged in sequence along the optical axis direction. The display screen includes a plurality of pixels and a driving circuit connected to the pixels. The driving parameters of the driving circuit are determined according to a target transmittance. The target transmittance is determined according to the transmittance of the pixels connected to the driving circuit and a corresponding area in the lens.

2. The display module according to claim 1, characterized in that: When each of the pixels displays the same grayscale, a first difference in display brightness between light emitted by any two of the pixels after passing through the lens is less than a first preset threshold; and / or a second difference in display chromaticity between light emitted by any two of the pixels after passing through the lens is less than a second preset threshold.

3. The display module according to claim 1 or 2, characterized in that: When each of the pixels displays the same gray scale, the driving current of the driving circuit and the target transmittance corresponding to the driving circuit are negatively correlated.

4. The display module according to claim 1, characterized in that: The driving circuit includes a red driving circuit, a green driving circuit and a blue driving circuit, the target transmittance includes a target red light transmittance, a target green light transmittance and a target blue light transmittance, the driving parameters of the red driving circuit are determined according to the target red light transmittance, the driving parameters of the green driving circuit are determined according to the target green light transmittance, and the driving parameters of the blue driving circuit are determined according to the target blue light transmittance; The target red light transmittance is determined according to the red light transmittance of the corresponding area in the lens of the pixel connected to the red light driving circuit, the target green light transmittance is determined according to the green light transmittance of the corresponding area in the lens of the pixel connected to the green light driving circuit, and the target blue light transmittance is determined according to the blue light transmittance of the corresponding area in the lens of the pixel connected to the blue light driving circuit.

5. The display module according to claim 1 or 4, characterized in that: The driving parameters include parameters that affect the driving current of the driving circuit.

6. The display module according to claim 5, characterized in that: The driving circuit includes a driving transistor, and the driving parameters include at least one of a reset voltage of the driving circuit, a coupling capacitance, a channel width of the driving transistor, a channel length of the driving transistor, a carrier mobility of the driving transistor, and an intrinsic capacitance of the driving transistor.

7. The display module according to claim 5, characterized in that: The driving circuit includes a driving transistor, and the driving parameters include a channel width of the driving transistor and a channel length of the driving transistor. A third ratio between a first ratio of the channel width and the channel length and a preset second ratio is equal to the inverse of the corresponding target transmittance, and the second ratio is the ratio of the channel width to the channel length of the driving transistor when the target transmittance is a preset value.

8. The display module according to claim 1, characterized in that: The corresponding area of ​​the pixel in the lens at least includes an area of ​​the lens directly facing the pixel.

9. The display module according to claim 1, characterized in that: The lens includes a plurality of lens areas, and different lens areas have different transmittances. The target transmittance is determined according to the transmittance of the lens area corresponding to the pixel connected to the driving circuit in the lens.

10. A head mounted display device, characterized in that: include: frame; and The display module according to any one of claims 1 to 9, wherein the display module is arranged on the frame.

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