CN111458911A

CN111458911A - Display device and light source module thereof

Info

Publication number: CN111458911A
Application number: CN201910048166.3A
Authority: CN
Inventors: 陈冰彦; 方崇仰
Original assignee: Taiwan Young Co ltd
Current assignee: Taiwan Young Co ltd
Priority date: 2019-01-18
Filing date: 2019-01-18
Publication date: 2020-07-28
Anticipated expiration: 2039-01-18
Also published as: CN111458911B; JP2020118965A; DE102020100790A1; TWI698668B; TW202028784A

Abstract

The invention provides a display device and a light source module thereof. The light source module comprises a backlight module and a light-emitting visual angle control device. The light-emitting visual angle control device is arranged on the backlight module. In the light-emitting visual angle control device, a first polarizer, a first alignment layer, a first liquid crystal layer, a second alignment layer and a second polarizer are sequentially arranged on a transmission path of an illumination beam from a backlight module. The alignment direction of the first alignment layer is vertical to that of the second alignment layer. The plurality of liquid crystal molecules in the first liquid crystal layer change their alignment direction according to the first applied voltage. When the first applied voltage is equal to 0V, the light-emitting viewing angle range of the illumination beam is a first viewing angle, and when the first applied voltage is greater than 0V, the light-emitting viewing angle range is a second viewing angle, wherein the second viewing angle is different from the first viewing angle. The display device comprises the light source module. The display device and the light source module can be switched between a forward viewing mode and a diagonal peep-proof mode.

Description

Display device and light source module thereof

Technical Field

The present invention relates to a display device, and more particularly, to a display device and a light source module capable of controlling a Viewing Angle range (Viewing Angle).

Background

With the development of technology, display devices have become commonly used electronic devices. While a wide viewing angle is required for a typical display device, some displays require a controlled viewing angle range to provide privacy functions. For example, when the automobile is traveling, the bright light of the display device for the automobile may cause the driver to be distracted or the display content may be distracted, but when the automobile is not traveling, the driver still wants to be able to view the display content of the display device for the automobile. Therefore, how to provide a display device capable of controlling the viewing angle range is an issue to be studied.

The background section is only used to help the understanding of the present invention, and therefore the disclosure in the background section may include some known techniques which do not constitute the knowledge of those skilled in the art. The statements in the "background" section do not represent that matter or the problems which may be solved by one or more embodiments of the present invention, but are known or appreciated by those skilled in the art before filing the present application.

Disclosure of Invention

Embodiments of the present invention provide a display device and a light source module, which can provide at least two different viewing angle ranges.

Other objects and advantages of the present invention will be further understood from the technical features disclosed in the present invention.

To achieve one or a part of or all of the above or other objects, an embodiment of the invention provides a light source module. The light source module comprises a backlight module and a light-emitting visual angle control device. The backlight module is used for emitting illumination light beams. The light-emitting visual angle control device is arranged on the backlight module along the transmission direction of the illuminating light beam and comprises a plurality of polaroids, a plurality of alignment layers and a liquid crystal layer. The first polarizer and the second polarizer are sequentially arranged on the transmission path of the illumination beam. The first liquid crystal layer is arranged on a transmission path of the illumination light beam and is positioned between the first polarizer and the second polarizer, wherein a plurality of liquid crystal molecules in the first liquid crystal layer change the arrangement direction of the liquid crystal molecules according to the first applied voltage. The first alignment layer is disposed on the transmission path of the illumination beam and between the first polarizer and the first liquid crystal layer. The second alignment layer is disposed on the transmission path of the illumination beam and between the second polarizer and the first liquid crystal layer, wherein the alignment direction of the first alignment layer is perpendicular to that of the second alignment layer. When the first applied voltage is equal to 0V (volt), the light-emitting viewing angle range after the illumination beam penetrates through the light-emitting viewing angle control device is a first viewing angle, and when the first applied voltage is greater than 0V, the light-emitting viewing angle range is a second viewing angle, wherein the second viewing angle is different from the first viewing angle.

An embodiment of the invention provides a display device. The display device comprises a light source module and a display module. The light source module comprises a backlight module and a light-emitting visual angle control device. The backlight module is used for emitting illumination light beams. The light-emitting visual angle control device is arranged on the backlight module along the transmission direction of the illumination light beam. In the light-emitting visual angle control device, a first polaroid and a second polaroid are sequentially arranged on a transmission path of an illuminating beam. The first liquid crystal layer is arranged on a transmission path of the illumination light beam and is positioned between the first polarizer and the second polarizer, wherein a plurality of liquid crystal molecules in the first liquid crystal layer change the arrangement direction of the liquid crystal molecules according to the first applied voltage. The first alignment layer is disposed on the transmission path of the illumination beam and between the first polarizer and the first liquid crystal layer. The second alignment layer is disposed on a transmission path of the illumination beam and between the second polarizer and the first liquid crystal layer, wherein an alignment direction of the first alignment layer is perpendicular to an alignment direction of the second alignment layer, wherein when the first applied voltage is equal to 0V, a light-emitting viewing angle range of the illumination beam after penetrating through the light-emitting viewing angle control device is a first viewing angle, and when the first applied voltage is greater than 0V, the light-emitting viewing angle range is a second viewing angle, wherein the second viewing angle is different from the first viewing angle. The display module is arranged on the light source module along the transmission direction of the illumination light beam and is used for converting the illumination light beam into a display light beam.

In view of the above, the display device and the light source module thereof according to the embodiment of the invention have at least two viewing modes with different viewing angles, including a forward viewing angle mode in which multiple persons view the display device together and a diagonal peep-proof mode in which only specific direction viewers are restricted from seeing the display device. If the display device is applied to the screen of the automobile, when the automobile advances, the display device is switched to the oblique peep-proof mode, so that the interference of a driver can be avoided, the running safety degree is improved, and meanwhile, a passenger on the auxiliary seat can still watch the display content of the display device.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic view of a display device according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a light source module according to an embodiment of the invention.

Fig. 3A is a schematic view illustrating an alignment direction and a viewing angle control direction of an alignment layer of a light-emitting viewing angle control device according to an embodiment of the invention.

Fig. 3B is a schematic diagram illustrating an alignment direction and a viewing angle control direction of an alignment layer of a light-emitting viewing angle control device according to another embodiment of the invention.

Fig. 4A to 4D are light-emitting field pattern distribution diagrams of the light-emitting viewing angle control device according to the embodiment of fig. 3A.

Fig. 5 is a distribution diagram of the light-emitting field pattern of the light-emitting visual angle control device in the horizontal viewing direction according to the embodiment of fig. 4A to 4D.

Fig. 6 is a schematic structural diagram of a light source module according to another embodiment of the invention.

Fig. 7A and 7B are schematic diagrams illustrating an alignment direction and a viewing angle control direction of an alignment layer of a light-emitting viewing angle control device according to another embodiment of the invention.

Fig. 8 is a distribution diagram of an outgoing light field pattern in a horizontal viewing direction of an outgoing light viewing angle control device according to the embodiment of fig. 6 to 7B.

Fig. 9 is a diagram illustrating a distribution of an outgoing light pattern in a horizontal viewing direction of an outgoing light viewing angle control apparatus according to another embodiment of the invention.

Fig. 10 is a schematic view of a display device according to another embodiment of the present invention.

Detailed Description

The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Figure 1 is a schematic view of a display device according to an embodiment of the present invention,

fig. 2 is a schematic structural diagram of a light source module according to an embodiment of the invention. Referring to fig. 1, a display device 10 includes a light source module 100 and a display module 200. The light source module 100 includes a backlight module 110 and a light-emitting viewing angle control device 120. The backlight module 110 is configured to emit an illumination beam IB, and the light-exiting viewing angle control device 120 is disposed on the backlight module 110 along a transmission direction (e.g., a Z direction) of the illumination beam IB, so as to adjust a light-exiting viewing angle of the illumination beam IB. The display module 200 is disposed on the light source module 100 along a transmission direction (e.g., Z direction) of the illumination beam IB, and is used for converting the illumination beam IB into the display beam DB.

Referring to fig. 2, fig. 2 schematically shows a structure of the light source module 100. the light-emitting viewing angle control device 120 at least includes a first polarizer 122, a second polarizer 124, a first liquid crystal layer L C1, a first alignment layer 126 and a second alignment layer 128. the first polarizer 122 and the second polarizer 124 are sequentially disposed on the transmission path of the illumination beam IB. the first liquid crystal layer L C1 is disposed on the transmission path of the illumination beam IB and between the first polarizer 122 and the second polarizer 124. the first alignment layer 126 is disposed on the transmission path of the illumination beam IB and between the first polarizer 122 and the first liquid crystal layer L C1. the second alignment layer 128 is disposed on the transmission path of the illumination beam IB and between the second polarizer 124 and the first liquid crystal layer L C4. furthermore, the alignment directions of the first alignment layer 126 and the second alignment layer 128 are perpendicular to each other, glass layers G5 and L C1 are disposed between the first polarizer 122 and the first alignment layer 126, and glass layers L are disposed between the second alignment layer 124 and the second alignment layer 4832.

When the first applied voltage is equal to 0V (volts), the light-emitting viewing angle range of the illumination beam IB after penetrating through the light-emitting viewing angle control device 120 is a first viewing angle, and when the first applied voltage is greater than 0V, the light-emitting viewing angle range is a second viewing angle, wherein the second viewing angle is different from the first viewing angle.

In brief, in the embodiment, the light-exiting visual angle control device 120 can change the light-exiting visual angle of the illumination beam IB from the backlight module 110 by controlling the magnitude of the first applied voltage to change the arrangement direction of the liquid crystal molecules of the first liquid crystal layer L C1, thereby adjusting the light-exiting visual angle range of the illumination beam IB passing through the light-exiting visual angle control device 120, so that the illumination beam IB passing through the display module 200 can provide at least two different visual angle ranges (e.g., a first visual angle and a second visual angle).

The remaining embodiments of the light viewing angle control device 120 are further described below.

In the present embodiment, the liquid crystal molecules of the first liquid crystal layer L C1 are Twisted Nematic (TN) liquid crystals, but are not limited.

In the present embodiment, after the first voltage is applied, the range of the light-emitting viewing angle is shifted, and the shift direction is determined based on the alignment directions of the first alignment layer 126 and the second alignment layer 128. The absorption axis of the first polarizer 122 may be parallel or perpendicular to the alignment direction of the first alignment layer 126, and the absorption axis of the second polarizer 124 may be parallel or perpendicular to the alignment direction of the second alignment layer 128.

In the present embodiment, an angle between the alignment direction of the first alignment layer 126 and the alignment direction of the second alignment layer 128 is, for example, 90 degrees. When the first applied voltage is equal to 0V, the light-emitting viewing angle (first viewing angle) of the illumination beam IB after penetrating through the light-emitting viewing angle control device 120 is substantially maintained, but when the first applied voltage is greater than 0V, the liquid crystal molecules start to deflect, the light-emitting viewing angle range of the illumination beam IB is changed from the first viewing angle to the second viewing angle, and the offset direction of the illumination beam IB forms an angle of 45 degrees with the alignment direction of the second alignment layer.

FIG. 3A is a schematic diagram showing the alignment direction and the viewing angle control direction of the alignment layers of the light-exiting viewing angle control device according to an embodiment of the present invention, referring to FIGS. 2 and 3A, the horizontal viewing direction is defined as the X direction and the vertical viewing direction is defined as the Y direction on the plane (e.g., X-Y plane) of the first liquid crystal layer L C1. the embodiment of FIG. 3A is applicable to the light-exiting viewing angle control device 120. the alignment direction 1261 of the first alignment layer 126 is 135 degrees with respect to the horizontal viewing line, the alignment direction 1281 of the second alignment layer 128 is 45 degrees with respect to the horizontal viewing line, and the alignment direction 1261 of the first alignment layer 126 and the alignment direction 1281 of the second alignment layer 128 form an angle of 90 degrees.

Fig. 4A to 4D are light-emitting field pattern distribution diagrams of the light-emitting visual angle control device according to the embodiment of fig. 3A, and fig. 5 is a light-emitting field pattern distribution diagram of the light-emitting visual angle control device according to the embodiment of fig. 4A to 4D in the horizontal line of sight direction. In fig. 4A, the first applied voltage is 0V (volt), and in fig. 4B to 4D, the first applied voltage is 1.6V, 1.8V, and 2V, respectively. Curves 510 to 540 in fig. 5 respectively show the changes of the light exit patterns in the horizontal line of sight directions in fig. 4A to 4D.

In the present embodiment, the backlight module 110 is exemplified by a lambertian light source (L ambertian), the polarization direction of the first polarizer 122 is perpendicular to the alignment direction 1261 of the first alignment layer 126, the polarization direction of the second polarizer 124 is also perpendicular to the alignment direction 1281 of the second alignment layer 128, before the first voltage is applied to the first liquid crystal layer L C1 (see fig. 4A and fig. 5, curve 510), the liquid crystal molecules maintain the original arrangement, the first viewing angle of the illumination beam IB passing through the light-exiting viewing angle control device 120 is still maintained within the wide viewing angle range, and the display device 10 operates in the forward viewing mode, so that viewers at different positions can view pictures together.

As the first applied voltage increases (see fig. 4B to fig. 5), the light-exiting field pattern of the illumination beam IB passing through the light-exiting viewing angle control device 120 changes, the viewing angle range becomes narrower and the viewing angle shifts toward the horizontal viewing direction (e.g., the right side in the diagrams of fig. 4B to fig. 5), see the shifting direction 130 of the light-exiting viewing angle range in fig. 3A. That is, the alignment direction 1261 of the first alignment layer 126 and the alignment direction 1281 of the second alignment layer 128 form an angle of 90 degrees, and the deviation direction 130 of the illumination beam IB from the first viewing angle to the second viewing angle changes to form an angle of 45 degrees with the alignment direction 1281 of the second alignment layer 128 after passing through the light-exiting viewing angle control device 120 with the increase of the first applied voltage. In addition, as can be seen from fig. 4A to 4D, the range of the first viewing angle may be larger than the range of the second viewing angle, and the ranges of the positive and negative angles of the second viewing angle in fig. 4B to 4D are significantly asymmetric. More specifically, the first viewing angle includes a viewing angle range of 60 degrees to-60 degrees, and the second viewing angle is a viewing angle range of greater than or equal to-30 degrees or less than or equal to 30 degrees.

That is, increasing the first applied voltage causes the range of the light-emitting viewing angle to be limited in a specific direction, especially in an oblique direction, so that the display device 10 can operate in an oblique anti-peeping mode, and only viewers in the specific direction can view the image to achieve the anti-peeping effect.

In short, the first viewing angle of the present embodiment is suitable for the forward viewing mode, the second viewing angle is suitable for the oblique viewing mode, and the offset direction from the first viewing angle to the second viewing angle is determined according to the alignment direction between the first alignment layer 126 and the second alignment layer 128. The light-emitting visual angle control device 120 is controlled by the first applied voltage to switch the display device 10 between the forward viewing mode and the oblique peep-proof mode.

In one embodiment, the embodiments of fig. 3A to 4D are applied to a central display device of an automobile. When the vehicle is not moving, the display device 10 operates in the forward viewing mode, and the driver in the driver seat and the passenger in the passenger seat can view the image of the display device 10 together, but when the vehicle is moving, the display device 10 can be switched to the oblique peep-proof mode, and the viewing angle range of the display device 10 is changed to provide the viewing of only the passenger in the passenger seat, and the driver cannot view the image of the display device 10, thereby achieving the effect of improving the driving safety.

Fig. 3B is a schematic diagram illustrating an alignment direction and a viewing angle control direction of an alignment layer of a light-emitting viewing angle control device according to another embodiment of the invention. Referring to fig. 3B, the alignment direction 1262 of the first alignment layer 126 is 45 degrees with respect to the horizontal viewing line, the alignment direction 1282 of the second alignment layer 128 is 135 degrees with respect to the horizontal viewing line, and the alignment direction 1262 of the first alignment layer 126 and the alignment direction 1282 of the second alignment layer 128 also form an angle of 90 degrees. In this embodiment, the shift direction 140 of the light-emitting viewing angle range from the first viewing angle to the second viewing angle is shifted to the left, opposite to the shift direction 130 in FIG. 3A, but the shift direction 140 is also at an angle of 45 degrees with respect to the alignment direction 1282 of the second alignment layer 128.

The embodiment of fig. 3B may obtain sufficient teaching, suggestion and implementation descriptions from the descriptions of fig. 3A and fig. 4A to 5, and thus, the description is not repeated.

Fig. 6 is a schematic structural diagram of a light source module according to another embodiment of the invention, the light source module 300 of fig. 6 is applicable to the display device 10 of fig. 1, the light source module 300 is partially similar to the light source module 100 of fig. 2, but the light-emitting viewing angle control device 310 of the light source module 300 further includes a second liquid crystal layer L C2, a third alignment layer 312, a fourth alignment layer 314, and a third polarizer 316.

The third polarizer 316 is disposed on the second polarizer 124 along the transmission direction of the illumination beam IB, the second liquid crystal layer L C2 is disposed on the transmission path of the illumination beam IB and between the third polarizer 316 and the second polarizer 124, the third alignment layer 312 is disposed on the transmission path of the illumination beam IB and between the second polarizer 124 and the second liquid crystal layer L C2, the fourth alignment layer 314 is disposed on the transmission path of the illumination beam IB and between the third polarizer 316 and the second liquid crystal layer L C2, wherein the alignment directions of the third alignment layer 312 and the fourth alignment layer 314 are perpendicular, a glass layer and a conductive layer are disposed between the alignment layer of the light-emitting visual angle control device 310 and the polarizer, for example, a glass layer G53925 and a conductive layer C L are disposed between the second polarizer 124 and the third alignment layer 312, and a glass layer G5394 and a conductive layer C6854 are disposed between the third polarizer 316 and the fourth polarizer 314 except for the original glass layers G L and G2, and C L and C L.

The liquid crystal molecules in the second liquid crystal layer L C2 change their alignment direction according to the second applied voltage, the light-emitting viewing angle of the illumination beam IB is a first viewing angle when the first applied voltage and the second applied voltage are both equal to 0V, and the light-emitting viewing angle is a third viewing angle when the first applied voltage and the second applied voltage are both greater than 0V, wherein the first viewing angle, the second viewing angle and the third viewing angle are different from each other.

In the present embodiment, the liquid crystal molecules of the first liquid crystal layer L C1 and the second liquid crystal layer L C2 may be Twisted Nematic (TN) liquid crystals, but are not limited thereto.

Fig. 7A and 7B are schematic diagrams illustrating an alignment direction and a viewing angle control direction of an alignment layer of a light-emitting viewing angle control device according to another embodiment of the invention. The embodiments of fig. 7A and 7B are suitable for the light-emitting viewing angle control device 310. FIG. 7A shows an alignment direction 1263 of the first alignment layer 126 and an alignment direction 1283 of the second alignment layer 128, which are arranged in the same manner as in the embodiment of FIG. 3A. The alignment direction 1263 of the first alignment layer 126 is 135 degrees with respect to the horizontal line of sight and the alignment direction 1283 of the second alignment layer 128 is 45 degrees with respect to the horizontal line of sight. Fig. 7B shows the alignment direction 3121 of the third alignment layer 312 and the alignment direction 3141 of the fourth alignment layer 314. The alignment direction 3121 of the third alignment layer 312 is 225 degrees from the horizontal line of sight and 180 degrees from the alignment direction 1263 of the second alignment layer 126. The alignment direction 3141 of the fourth alignment layer 314 is 315 degrees from the horizontal line of sight, which is also 180 degrees from the alignment direction 1263 of the first alignment layer 126. In this configuration, the light-emitting angle range of the illumination light beam IB emitted from the light source module 300 is shifted to the right, as indicated by the arrow 320.

Fig. 8 is a distribution diagram of an outgoing light field pattern in a horizontal viewing direction of an outgoing light viewing angle control device according to the embodiment of fig. 6 to 7B. The backlight module 110 is also a lambertian light source here. The curve 810 shows the light-exiting field pattern generated when the first applied voltage and the second applied voltage are both equal to 0V, which is the intensity distribution of the first viewing angle in the horizontal viewing direction. The curve 820 shows the light-exiting field pattern generated when the first applied voltage and the second applied voltage are not equal to 0V, which is the intensity distribution of the third viewing angle in the horizontal viewing direction. In the embodiment represented by curve 820, the first applied voltage is 2V and the second applied voltage is 1.8V. The first applied voltage may be greater than the second applied voltage.

Specifically, the first applied voltage and the second applied voltage may be smaller than the voltage applied to the liquid crystal layer in the display module 200. For example, the voltage required to turn the molecules in the liquid crystal layer in the display module 200 may be between 2.5V and 3.3V, which is greater than the first applied voltage and the second applied voltage.

In the above embodiment, the first applied voltage changes the arrangement of the liquid crystal molecules in the first liquid crystal layer L C1 to achieve the anti-peeping effect of providing the viewing frame of the viewer at the oblique position (see fig. 5), while the second liquid crystal layer L C2 is configured to further suppress the light-emitting field in the direction other than the viewing direction, for example, the curve 810 in fig. 8 corresponds to a forward viewing mode with a left-right symmetric viewing effect, the curve 820 corresponds to an anti-peeping mode, and is suitable for providing the viewing frame of the viewer at the oblique horizontal direction greater than-30 degrees, and in the range less than-30 degrees, the light-emitting amount of the illumination beam IB is significantly suppressed to achieve a better anti-peeping effect.

Fig. 9 is a diagram illustrating a distribution of an outgoing light pattern in a horizontal viewing direction of an outgoing light viewing angle control apparatus according to another embodiment of the invention. In the present embodiment, the backlight module 110 in the light source module 300 is changed to the existing light source for vehicle. The curve 910 is the light-emitting pattern in the forward viewing mode, i.e. the first applied voltage and the second applied voltage are 0V. The curve 920 is the light-exiting field pattern in the oblique privacy mode, i.e. both the first applied voltage and the second applied voltage are greater than 0V. In the forward viewing mode, the viewers at the left and right sides of the display device 10 can see the image, but in the oblique peep-proof mode, the viewer at the right side (viewing angle greater than 0 degree) can see the image, and the viewer at the left side (viewing angle less than 0 degree), especially the viewer at viewing angle less than-35 degree, cannot see the image, which means that the present embodiment can provide two viewing modes with different viewing angle ranges, wherein one viewing mode also has a good peep-proof effect.

Fig. 10 is a schematic view of a display device according to another embodiment of the present invention. The display device 20 includes a display module 210 and a light source module 340. The light source module 340 emits an illumination beam IB, and the display module 210 is disposed on the light source module 340 along a transmission direction of the illumination beam IB for converting the illumination beam IB into a display beam DB. The light source module 340 is substantially similar to the light source module 300, and will be further described below. The display module 210 includes a fourth polarizer 220, a display layer 230, and a fifth polarizer 240. The fourth polarizer 220 and the fifth polarizer 240 are sequentially disposed on the transmission path of the illumination beam IB, and the display layer 230 is disposed on the transmission path of the illumination beam IB and between the fourth polarizer 220 and the fifth polarizer 230. The display module 210 is suitable for matching with the light source module of each of the above embodiments.

Specifically, the light source module 340 may have the same structure as the light source module 300, and the light source module 340 also includes the third polarizer 334. The third polarizer 334 is disposed between the second polarizer 124 and the fourth polarizer 220 along the transmission direction of the illumination beam IB, wherein the absorption axis of the third polarizer 334 is parallel or perpendicular to the alignment direction of the fourth alignment layer 314. However, in one embodiment, the third polarizer 334 is not required, and the fourth polarizer 220 may replace the third polarizer 334.

In addition, in the present embodiment, the display device 20 may further include an optical phase retardation layer 332. The optical phase retardation layer 332 is disposed on the transmission path of the illumination beam IB and between the fourth alignment layer 314 and the fourth polarizer 220. The display module 210 may be an In-Plane Switching (IPS) panel. If the polarization direction of the fourth polarizer 220 of the display module 210 is not consistent with the illumination beam IB from the light source module 340, the optical phase retardation layer 332 may correct the polarization direction of the illumination beam IB to make it smoothly enter the display module 210. The optical phase retardation layer 332 is, for example, a half-wave plate, but is not limited thereto.

In summary, the exemplary embodiments of the invention provide a display device and a light source module. The light source module is provided with a light-emitting visual angle control device, and the light-emitting visual angle control device adjusts the light-emitting field type of the illuminating light beams by changing the arrangement mode of liquid crystal molecules in the first liquid crystal layer, so that the display device can be switched between a forward viewing mode and an oblique peep-proof mode. In the forward viewing mode, the viewing angle of the display device is substantially close to the viewing angle range provided by the backlight module. By controlling the magnitude of the first applied voltage, the visual angle range of the oblique peep-proof mode is changed along with the first applied voltage, so as to meet the requirements of different angles. The display device and the light source module can provide a low-power and high-luminance peep-proof mode.

It should be understood that the above-mentioned embodiments are only preferred embodiments of the present invention, and that the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made by the claims and the summary of the invention should be included in the scope of the present invention. It is not necessary for any embodiment or claim of the invention to address all of the objects, advantages, or features disclosed herein. In addition, the abstract and the title of the invention are provided for assisting the search of patent documents and are not intended to limit the scope of the invention. Furthermore, the terms "first", "second", and the like in the description or the claims are used only for naming elements (elements) or distinguishing different embodiments or ranges, and are not used to limit upper or lower limits on the number of elements.

Description of reference numerals:

10. 20: display device

100. 300, 340: light source module

110: backlight module

120. 310, 330: light-emitting visual angle control device

122: a first polarizer

124: second polarizer

126: a first alignment layer

1261. 1281, 1262, 1282, 1263, 1283, 3121, 3141: direction of alignment

128: second alignment layer

130. 140, 320: direction of offset

200. 210: display module

220: the fourth polarizer

230: display layer

240: fifth polarizer

312: third alignment layer

314: a fourth alignment layer

316. 334: third polarizer

332: optical phase retardation layer

510-540, 810, 820, 910, 920: curve line

DB: display light beam

IB: illuminating light beam

G L1, G L2, G L3, G L4 glass layer

C L1, C L2, C L3 and C L4 conductive layers

L C1 first liquid crystal layer

L C2 second liquid crystal layer

X, Y, Z: and (4) direction.

Claims

1. A light source module, comprising a backlight module and a light-emitting viewing angle control device, wherein:

the backlight module is used for emitting illumination light beams; and

the light-emitting visual angle control device is arranged on the backlight module along the transmission direction of the illuminating light beam and comprises a first polaroid, a second polaroid, a first liquid crystal layer, a first alignment layer and a second alignment layer, wherein:

the first polarizer and the second polarizer are sequentially arranged on the transmission path of the illumination light beam;

the first liquid crystal layer is arranged on a transmission path of the illumination light beam and positioned between the first polarizer and the second polarizer, wherein a plurality of liquid crystal molecules in the first liquid crystal layer change the arrangement direction of the liquid crystal molecules according to a first applied voltage;

the first alignment layer is arranged on the transmission path of the illumination light beam and positioned between the first polarizer and the first liquid crystal layer; and

the second alignment layer is disposed on the transmission path of the illumination beam and between the second polarizer and the first liquid crystal layer, wherein the alignment direction of the first alignment layer is perpendicular to that of the second alignment layer,

wherein, when the first applied voltage is equal to 0V, the light-emitting visual angle range of the illuminating light beam after penetrating through the light-emitting visual angle control device is a first visual angle, and when the first applied voltage is more than 0V, the light-emitting visual angle range is a second visual angle,

wherein the second viewing angle is different from the first viewing angle.

2. The light source module of claim 1, wherein the absorption axis direction of the first polarizer is parallel or perpendicular to the alignment direction of the first alignment layer, and the absorption axis direction of the second polarizer is parallel or perpendicular to the alignment direction of the second alignment layer.

3. The light source module of claim 1, wherein an alignment direction of the first alignment layer is one of 45 degrees or 135 degrees with respect to a horizontal line of sight, and an alignment direction of the second alignment layer is the other of 45 degrees or 135 degrees with respect to the horizontal line of sight, in a plane of the first liquid crystal layer.

4. The light source module of claim 1, wherein the range of the first viewing angle is greater than the range of the second viewing angle, and the range of positive and negative angles of the second viewing angle is asymmetric.

5. The light source module of claim 1, wherein the first viewing angle comprises a viewing angle range of 60 degrees to-60 degrees, and the second viewing angle is a viewing angle range greater than or equal to-30 degrees or less than or equal to 30 degrees.

6. The light source module of claim 1, wherein the light-emitting viewing angle control device further comprises:

a third polarizer disposed on the second polarizer along the transmission direction of the illumination beam;

a second liquid crystal layer disposed on a transmission path of the illumination beam and between the third polarizer and the second polarizer, wherein a plurality of liquid crystal molecules in the second liquid crystal layer change their alignment direction according to a second applied voltage;

a third alignment layer disposed on a transmission path of the illumination beam and between the second polarizer and the second liquid crystal layer; and

a fourth alignment layer disposed on a transmission path of the illumination beam and between the third polarizer and the second liquid crystal layer, wherein the alignment direction of the third alignment layer is perpendicular to that of the fourth alignment layer,

wherein when the first applied voltage and the second applied voltage are both equal to 0V, the light-emitting viewing angle of the illumination beam is the first viewing angle, and when the first applied voltage and the second applied voltage are both greater than 0V, the light-emitting viewing angle is the third viewing angle, wherein the first viewing angle, the second viewing angle and the third viewing angle are different from each other.

7. The light source module of claim 6, wherein the alignment directions of the second and third alignment layers are different by 180 degrees, and the alignment directions of the first and fourth alignment layers are different by 180 degrees.

8. The light source module of claim 6, wherein the first applied voltage is greater than the second applied voltage.

9. The light source module of claim 6, wherein the range of the third viewing angle is smaller than the range of the second viewing angle and the first viewing angle.

10. The light source module according to claim 6, wherein liquid crystal molecules of the first liquid crystal layer or the second liquid crystal layer are twisted nematic liquid crystals.

11. The light source module of claim 1, wherein the first viewing angle is suitable for a forward viewing mode, the second viewing angle is suitable for a diagonal privacy mode, and a shift direction from the first viewing angle to the second viewing angle is determined according to an alignment direction between the first alignment layer and the second alignment layer.

12. The light source module of claim 1, wherein when the first applied voltage is greater than 0V, the shift direction of the light-emitting viewing angle range from the first viewing angle to the second viewing angle is 45 degrees from the alignment direction of the second alignment layer.

13. A display device, comprising a light source module and a display module, wherein:

the light source module comprises a backlight module and a light-emitting visual angle control device, wherein:

the backlight module is used for emitting illumination light beams; and

wherein the second perspective is different from the first perspective; and

the display module is arranged above the light source module along the transmission direction of the illumination light beam and is used for converting the illumination light beam into a display light beam.

14. The display device according to claim 13, wherein the display module comprises:

the fourth polarizer and the fifth polarizer are sequentially arranged on the transmission path of the illumination light beam; and

the display layer is arranged on a transmission path of the illumination light beam and is positioned between the fourth polarizer and the fifth polarizer;

wherein, the light-emitting visual angle control device further comprises:

a second liquid crystal layer disposed on a transmission path of the illumination beam and between the fourth polarizer and the second polarizer, wherein a plurality of liquid crystal molecules in the second liquid crystal layer change their alignment direction according to a second applied voltage;

a fourth alignment layer disposed on a transmission path of the illumination beam and between the fourth polarizer and the second liquid crystal layer, wherein the third alignment layer is perpendicular to the alignment direction of the fourth alignment layer,

wherein, when first applied voltage with when second applied voltage all equals 0V, the illuminating beam pierces through the light-emitting visual angle behind the light-emitting visual angle controlling means is first visual angle, and, when first applied voltage with when second applied voltage all is greater than 0V, the light-emitting visual angle is the third visual angle, wherein, first visual angle, the second visual angle with the third visual angle is inequality each other.

15. The display device according to claim 14, further comprising:

and the optical phase delay layer is arranged on the transmission path of the illumination light beam and is positioned between the fourth alignment layer and the fourth polarizer.

16. The display device according to claim 14, wherein the light-exiting viewing angle control device further comprises:

and a third polarizer disposed between the second polarizer and the fourth polarizer along the transmission direction of the illumination beam, wherein the absorption axis direction of the third polarizer is parallel to or perpendicular to the alignment direction of the fourth alignment layer.