POLARIZED TYPE VIEWING ANGLE CONTROL DEVICE, POLARIZED TYPE VIEWING ANGLE CONTROL DISPLAY APPARATUS AND POLARIZED TYPE VIEWING ANGLE CONTROL LIGHT SOURCE MODULE

A polarized type viewing angle control device including a first polarizer, a second polarizer, a first O-plate compensation film, and a second O-plate compensation film is provided. The first polarizer has a first transmission axis. The second polarizer has a second transmission axis parallel to the first transmission axis. The first and second O-plate compensation films are located between the first and second polarizers and respectively have a first optical axis and a second optical axis. An orthogonal projection of the first optical axis on the first polarizer and an orthogonal projection of the second optical axis on the second polarizer are parallel or perpendicular to the first transmission axis and the second transmission axis. The second optical axis and the first optical axis have opposite inclination directions. A polarized type viewing angle control display device and a polarized type viewing angle control light source module are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serial no. 201710991534.9, filed on Oct. 23, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an optical device, a display apparatus, and a light source module, and particularly relates to a polarized type viewing angle control device, a polarized type viewing angle control display apparatus, and a polarized type viewing angle control light source module.

2. Description of Related Art

In general, in order to be viewable for a plurality of viewers at the same time, a display apparatus is usually provided with a display effect of wide viewing angle. However, in some circumstances or occasions, such as browsing private webpage or confidential information or inputting a password in a public occasion, such private or confidential information may be peeped by others and leaked due to the display effect of wide viewing angle. In order to protect privacy, it is common to dispose a light control film (LCF) in front of the display apparatus, and filter out light beams at a great angle. However, in addition to being expensive and thick, the light control film also reduces about 30% of the overall luminance of the display apparatus. Besides, the periodic structure of the light control film may easily generate a Moire pattern when used with the display apparatus, so the display quality may be affected.

SUMMARY OF THE INVENTION

The invention provides a polarized type viewing angle control device capable of limiting a viewing angle, reducing Moire pattern, and preventing a significant decrease in luminance.

The invention also provides a polarized type viewing angle control display apparatus and a polarized type viewing angle control light source module using the polarized type viewing angle control device.

Other objects and advantages of the invention can be further illustrated by the technical features broadly embodied and described as follows.

In order to achieve one, some, or all of the objects, an embodiment of the invention provides a polarized type viewing angle control device including a first polarizer, a second polarizer, a first O-plate compensation film, and a second O-plate compensation film. The first polarizer has a first transmission axis. The second polarizer is located at a side of the first polarizer and has a second transmission axis. The first O-plate compensation film is located between the first polarizer and the second polarizer and has a first optical axis. The second O-plate compensation film is located between the first O-plate compensation film and the second polarizer and has a second optical axis. The first transmission axis is parallel to the second transmission axis. An orthogonal projection of the first optical axis on the first polarizer is parallel or perpendicular to the first transmission axis and the second transmission axis. The second optical axis and the first optical axis have opposite inclination directions. An orthogonal projection of the second optical axis on the second polarizer is parallel or perpendicular to the first transmission axis and the second transmission axis.

In order to achieve one, some, or all of the objects, an embodiment of the invention provides a polarized type viewing angle control display apparatus including a display module and a polarized type viewing angle control device. The display module includes a first polarizer. The first polarizer has a first transmission axis. The polarized viewing angle control device is disposed at side of the display module closer to the first polarizer. The polarized type viewing angle control device includes a second polarizer, a first O-plate compensation film and a second O-plate compensation film. The second polarizer has a second transmission axis. The first O-plate compensation film is located between the first polarizer and the second polarizer and has a first optical axis. The second O-plate compensation film is located between the first O-plate compensation film and the second polarizer and has a second optical axis. The first transmission axis is parallel to the second transmission axis. An orthogonal projection of the first optical axis on the first polarizer is parallel or perpendicular to the first transmission axis and the second transmission axis. The second optical axis and the first optical axis have opposite inclination directions. An orthogonal projection of the second optical axis on the second polarizer is parallel or perpendicular to the first transmission axis and the second transmission axis.

In order to achieve one, some, or all of the objects, an embodiment of the invention provides a polarized type viewing angle control light source module including a light source module and a polarized type viewing angle control device. The polarized type viewing angle control device is disposed at a light emitting side of the light source module and includes a first polarizer, a second polarizer, a first O-plate compensation film, and a second O-plate compensation film. The first polarizer has a first transmission axis. The second polarizer is located at a side of the first polarizer and has a second transmission axis. The first O-plate compensation film is located between the first polarizer and the second polarizer and has a first optical axis. The second O-plate compensation film is located between the first O-plate compensation film and the second polarizer and has a second optical axis. The first transmission axis is parallel to the second transmission axis. An orthogonal projection of the first optical axis on the first polarizer is parallel or perpendicular to the first transmission axis and the second transmission axis. The second optical axis and the first optical axis have opposite inclination directions. An orthogonal projection of the second optical axis on the second polarizer is parallel or perpendicular to the first transmission axis and the second transmission axis.

Based on the above, the embodiments of the invention have at least one of the following advantages or effects. In the polarized type viewing angle control device, the polarized type viewing angle control display apparatus, and the polarized type viewing angle control light source module according to the embodiments of the invention, the required phase retardation value is provided by two O-plate compensation films together with two polarizers, so as to limit the viewing angle at the azimuth angle to be controlled. Since the polarized type viewing angle control device does not control the viewing angle by using a periodic structure, Moiré patterns may be avoided. Compared with known products, such as a light control film, the polarized viewing angle control device has a higher luminance from a center view, a lower cost, and a thinner thickness. By limiting the viewing angle in a single direction (e.g., lengthwise or widthwise direction), the polarized type viewing angle control device may be applied in a full anti-peep display or a vehicle display.

Other objects, features and advantages of the present invention will be further understood from the further technological features disclosed by the embodiments of the present invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1Ais a schematic cross-sectional view illustrating a polarized type viewing angle control device according to a first embodiment of the invention. Referring toFIG. 1, a polarized type viewing angle control device100in the first embodiment of the invention includes a first polarizer P1, a second polarizer P2, a first O-plate compensation film O1, and a second O-plate compensation film O2.

The first polarizer P1has a first transmission axis T1. The second polarizer P2is located at a side of the first polarizer P1and has a second transmission axis T2. The first O-plate compensation film O1is located between the first polarizer P1and the second polarizer P2and has a first optical axis OA1. The second O-plate compensation film O2is located between the first O-plate compensation film O1and the second polarizer P2and has a second optical axis OA2. The first transmission axis T1is parallel to the second transmission axis T2. An orthogonal projection OP1of the first optical axis OA1on the first polarizer P1is parallel or perpendicular to the first transmission axis T1and the second transmission axis T2. The second optical axis OA2and the first optical axis OA1have opposite inclination directions, and an orthogonal projection OP2of the second optical axis OA2on the second polarizer P2is parallel or perpendicular to the first transmission axis T1and the second transmission axis T2.

For example, as shown in a dash line frame X1, the first transmission axis T1and the second transmission axis T2may respectively extend in a first direction D1parallel to the first polarizer P1. In addition, the orthogonal projection OP1of the first optical axis OA1on the first polarizer P1and the orthogonal projection OP2of the second optical axis OA2on the second polarizer P2are parallel to the first transmission axis T1and the second transmission axis T2. Moreover, an acute angle included between the first optical axis OA1and the first polarizer P1(i.e., an acute angle θ1included between the first optical axis OA1and the orthogonal projection OP1) is the same as or similar to an acute angle included between the second optical axis OA2and the second polarizer P2(i.e., an acute angle θ2included between the second optical axis OA2and the orthogonal projection OP2). Here, the acute angle θ1being similar to the acute angle θ2indicates that a difference between the acute angle θ1and the acute angle θ2is no more than 5 five degrees.

In the embodiment, the polarized type viewing angle control device100is able to limit the viewing angle in a second direction D2. The second direction D2is perpendicular to the first direction D1and a thickness direction of the polarized type viewing angle control device100(e.g., a third direction D3). More specifically, an anti-peep direction of the polarized type viewing angle control device100may be parallel to the first polarizer P1(or the second polarizer P2) and perpendicular to the orthogonal projection OP1of the first optical axis OA1(or the orthogonal projection OP2of the second optical axis OA2). In the configuration of the dash line frame X1, the orthogonal projection OP1of the first optical axis OA1and the orthogonal projection OP2of the second optical axis OA2are parallel to the first direction D1. Therefore, the polarized type viewing angle control device100limits the viewing angle in the second direction D2. In another embodiment, the orthogonal projection OP1of the first optical axis OA1and the orthogonal projection OP2of the second optical axis OA2may be parallel to the second direction D2. Accordingly, the polarized type viewing angle control device100may limit the viewing angle in the first direction D1.

In addition, as shown in a dash line frame X2, the first transmission axis T1and the second transmission axis T2may respectively extend in the second direction D2. In addition, the orthogonal projection OP1of the first optical axis OA1on the first polarizer P1and the orthogonal projection OP2of the second optical axis OA2on the second polarizer P2are perpendicular to the first transmission axis T1and the second transmission axis T2. Moreover, the acute angle θ1may be the same as or similar to the acute angle θ2. In the configuration of the dash line frame X2, the orthogonal projection OP1of the first optical axis OA1and the orthogonal projection OP2of the second optical axis OA2are parallel to the first direction D1. Therefore, the polarized type viewing angle control device100limits the viewing angle in the second direction D2.

FIGS. 1B and 1Care respectively two partially enlarged schematic cross-sectional views illustrating two O-plate compensation films ofFIG. 1A. Referring toFIGS. 1B and 1C, the first O-plate compensation film O1and the second O-plate compensation film O2respectively have a plurality of liquid crystal molecules LC. The liquid crystal molecules LC respectively have optical axes OA, and angles β are included between the optical axes OA of the liquid crystal molecules LC and an interface I between the first O-plate compensation film O1and the second O-plate compensation film O2. In the first O-plate compensation film O1and the second O-plate compensation film O2, the angles β become greater as a distance between the liquid crystal molecules LC and the interface I increases (Referring toFIG. 1B). Alternatively, the angles β may become smaller as the distance between the liquid crystal molecules LC and the interface I increases (Referring toFIG. 1C). In the first O-plate compensation film O1, an average of the angles β included between the optical axes OA of the liquid crystal molecules LC and the interface I is the acute angle θ1shown inFIG. 1A. Similarly, in the second O-plate compensation film O2, an average of the angles β included between the optical axes OA of the liquid crystal molecules LC and the interface I is the acute angle θ2shown inFIG. 1A.

FIG. 1Dis a diagram illustrating a relation between transmittance and zenith angle of a polarized type viewing angle control device of a first embodiment at different acute angles in a direction with an azimuth angle of 0°-180°.FIG. 1Eis a diagram illustrating a relation between transmittance and zenith angle of the polarized type viewing angle control device of the first embodiment at different acute angles in a direction with an azimuth angle of 90°-270°. Specifically,FIGS. 1D and 1Eare results obtained through simulation based on the configuration where the dash line frame X1ofFIG. 1Ais used with the liquid crystal arrangement ofFIG. 1C, wherein the first direction D1and an opposite direction thereof correspond to the azimuth angle of 0°-180°, and the second direction D2and an opposite direction thereof correspond to the azimuth angle of 90°-270°. In addition, the acute angle θ1and the acute angle θ2ofFIG. 1Aare represented by an acute angle θ inFIGS. 1D and 1E, where 0=20° indicates that the acute angle θ1and the acute angle θ2inFIG. 1Aare both 20°. Other angles may be inferred based on the same principle. Therefore, details in this regard will not be repeated in the following.

As shown inFIGS. 1D and 1E, in the configuration that the first transmission axis of the first polarizer and the second transmission axis of the second polarizer respectively extend in the first direction, in the case where the acute angle θ is within a range from 20° to 50°, the transmittance of the polarized type viewing angle control device at the azimuth angle of 0°-180° (i.e., in the first direction D1and the opposite direction thereof) barely changes when the zenith angle is within a range from −55° to 55°. In addition, the transmittance of the polarized type viewing angle control device at the azimuth angle of 90°-270° (i.e., in the second direction D2and the opposite direction thereof) gradually decreases as an absolute value of the zenith angle gradually becomes greater. In other words, the polarized type viewing angle control device100has the effect of limiting the viewing angle in the direction of the azimuth angle of 90°-270° (i.e., in the second direction D2and the opposite direction thereof).

In addition, according toFIG. 1E, the viewing angle of the polarized type viewing angle control device may become narrowed as the acute angle θ becomes greater. Besides, as the acute angle θ becomes greater, the polarized type viewing angle control device gradually shows light leakage at a large angle. As the acute angle θ becomes smaller, the viewing angle of the polarized type viewing angle control device gradually becomes broader. Hence, by keeping the acute angle θ within a range from 20° to 50°, the polarized type viewing angle control device may have a narrowed viewing angle and have less light leakage at a large angle. Specifically, in the embodiment ofFIG. 1A, the acute angle included between the first optical axis OA1and the first polarizer P1(i.e., the acute angle θ1included between the first optical axis OA1and the orthogonal projection OP1) falls within the range from 20° to 50°, and the acute angle included between the second optical axis OA2and the second polarizer P2(i.e., the acute angle θ2included between the second optical axis OA2and the orthogonal projection OP2) falls within the range from 20° to 50°. In addition, a difference between the acute angle θ1and the acute angle θ2is no more than 5 degrees.

FIG. 1Fis a diagram illustrating a relation between transmittance and zenith angle of the polarized type viewing angle control device of the first embodiment at different phase retardation values in a direction with an azimuth angle of 0°-180°.FIG. 1Gis a diagram illustrating a relation between transmittance and zenith angle of the polarized type viewing angle control device of the first embodiment at different phase retardation values in a direction with an azimuth angle of 90°-270°. More specifically,FIGS. 1F and 1Gare results of simulation obtained in the configuration where the dash line frame X1ofFIG. 1Ais used with the liquid crystal arrangement ofFIG. 1C. InFIGS. 1F and 1G, 100 nm indicates that a phase retardation value of the first O-plate compensation film and a phase retardation value of the second O-plate compensation film are both 100 nm. Other phase retardation values may be inferred based on the same principle. Therefore, details in this regard will not be repeated in the following.

As shown inFIGS. 1F and 1G, in the configuration that the first transmission axis of the first polarizer and the second transmission axis of the second polarizer respectively extend in the first direction, in the case where the phase retardation value of the first O-plate compensation film and the phase retardation value of the second O-plate compensation film respectively fall within a range from 100 nm to 400 nm, the transmittance of the polarized type viewing angle control device at the azimuth angle of 0°-180° (i.e., in the first direction D1and the opposite direction thereof) barely changes when the zenith angle is within a range from −55° to 55°. In addition, the transmittance of the polarized type viewing angle control device100at the azimuth angle of 90°-270° (i.e., in the second direction D2and the opposite direction thereof) gradually decreases as the absolute value of the zenith angle gradually increases. In other words, the polarized type viewing angle control device100has the effect of limiting the viewing angle in the direction of the azimuth angle of 90°-270° (i.e., in the second direction D2and the opposite direction thereof).

In addition, according toFIG. 1G, the viewing angle of the polarized type viewing angle control device may be narrowed as the phase retardation value of the O-shape compensation film increases. Besides, as the phase retardation value of the O-shape compensation film increases, the polarized type viewing angle control device gradually shows some light leakage at a large angle. As the phase retardation value of the O-shape compensation film decreases, the viewing angle of the polarized type viewing angle control device gradually becomes broader. Hence, by keeping the phase retardation value within a range from 100 nm to 400 nm, the polarized type viewing angle control device may have a narrowed viewing angle and have no light leakage at a large angle. Specifically, in the embodiment ofFIG. 1A, the phase retardation value of the first O-plate compensation film O1falls within the range from 100 nm to 400 nm, and the phase retardation value of the second O-plate compensation O2falls within the range from 100 nm to 400 nm. In addition, a difference between the phase retardation value of the first O-plate compensation film O1and the phase retardation value of the second O-plate compensation film O2is no more than 50 nm.

In addition, in the configuration ofFIG. 1A, when the first polarizer P1is closer to the user, the first polarizer P1may be an absorptive polarizer, for example, and the second polarizer P2may be an absorptive polarizer or a reflective polarizer. Since the polarization (defined as the capability of filtering out light beams in a specific polarization direction) of the absorptive polarizer is higher than the polarization of the reflective polarizer, when the second polarizer P2is an absorptive polarizer, the polarized type viewing angle control device100may have a desirable anti-peep effect. Alternatively, when the second polarizer P2is a reflective polarizer, the polarized viewing angle control device100may have a desirable light utilization rate.

FIGS. 2 to 5are respectively schematic cross-sectional views illustrating polarized type viewing angle control devices according to second to fifth embodiments of the invention. Polarized viewing angle control devices inFIGS. 2 to 5are similar to the polarized viewing angle control device100shown inFIG. 1A. In addition, like components are referred to by like reference symbols, and detailed descriptions thereof will not be repeated in the following.

Referring toFIG. 2, a polarized viewing angle control device200mainly differs from the polarized viewing angle control device ofFIG. 1Ain that the polarized viewing angle control device200further includes an adhesive layer AD. The adhesive layer AD is located between the first O-plate compensation film O1and the second O-plate compensation film O2to bond the first O-plate compensation film O1and the second O-plate compensation film O2. The modification is applicable to all the following embodiments. Therefore, details in this regard will not be repeated in the following.

Referring toFIG. 3, a polarized viewing angle control device300mainly differs from the polarized viewing angle control device ofFIG. 1Ain that the polarized viewing angle control device300further includes a third polarizer P3, and the second polarizer P2is located between the third polarizer P3and the second O-plate compensation film O2. The third polarizer P3has a third transmission axis T3parallel to the first transmission axis T1and the second transmission axis T2. The third polarizer P3may be an absorptive polarizer or a reflective polarizer, preferably a reflective polarizer. When the polarization of the second polarizer P2is insufficient (indicating that the second polarizer P2is unable to effectively filter out light beams in a specific polarization direction intended to be filtered out), the light filtering effect at the side where the second polarizer is located may be facilitated by disposing the third polarizer P3, and the anti-peep effect is consequently facilitated. The modification is applicable to all the following embodiments. Therefore, details in this regard will not be repeated in the following.

Referring toFIG. 4, a polarized viewing angle control device400mainly differs from the polarized viewing angle control device ofFIG. 1Ain that the polarized viewing angle control device400further includes a compensation film C. The compensation film C is located between the first O-plate compensation film O1and the second O-plate compensation film O2, and the compensation film C may be a C-plate compensation film or an O-plate compensation film. Taking the compensation film C as a C-plate compensation film as an example, the optical axis OA of the compensation film C is parallel to a thickness direction of the polarized type viewing angle control device400(the third direction D3). The compensation film C may serve to modify a light filtering range and the transmittance. For example, the compensation film C may offer an out-of-plane retardation of 150 nm, so as to further facilitate the anti-peep effect. It should be noted that, whileFIG. 4only illustrates one compensation film C, the number of the compensation film C may be modified based on needs, and is not limited to the illustration ofFIG. 4. The modification is applicable to all the following embodiments. Therefore, details in this regard will not be repeated in the following.

Referring toFIG. 5, a polarized viewing angle control device500mainly differs from the polarized viewing angle control device ofFIG. 1Ain that the polarized viewing angle control device500further includes two compensation films C. One of the compensation films C is located between the first O-plate compensation film O1and the first polarizer P1, and the other of the compensation films C is located between the second O-plate compensation film O2and the second polarizer P2. The two compensation films C may be C-plate compensation films or O-plate compensation films. Besides, the number of the compensation films C may be modified based on needs, and is not limited to the illustration ofFIG. 5. The modification is applicable to all the following embodiments. Therefore, details in this regard will not be repeated in the following.

FIG. 6is a schematic cross-sectional view illustrating a polarized type viewing angle control display apparatus according to a first embodiment of the invention. Referring toFIG. 6, a polarized type viewing angle control display apparatus10of the first embodiment of the invention includes a display module12and a polarized type viewing angle control device14. The display module12includes a display panel DP and the first polarizer P1. The polarized type viewing angle control device14is disposed at a side of the display module12closer to the first polarizer P1, and the polarized type viewing angle control device14includes the second polarizer P2, the first O-plate compensation film O1and the second O-plate compensation film O2. Details of the first polarizer P1, the second polarizer P2, the first O-plate compensation film O1and the second O-plate compensation film O2are already described above, and thus will not be repeated in the following.

The display panel DP may be a self-illuminating display panel or a non-self-illuminating display panel. When the display panel DP is a non-self-illuminating panel, the polarized viewing angle control display apparatus10may further include a light source module BL, such as a direct type light source module or a side type light source module, to provide an illumination beam. Alternatively, when the display panel DP is a self-illuminating display panel, the light source module BL may be omitted.

Taking a non-self-illuminating display panel as an example, when the display panel DP is a liquid crystal display panel, the display module12may include two polarizers P. The two polarizers P are disposed at opposite sides of the display panel DP, and transmission axes (not shown) of the two polarizers P may be parallel or perpendicular to each other. Furthermore, the transmission axis (not shown) of the polarizer P of the two polarizers P closer to the polarized type viewing angle control device14is parallel to the transmission axis (not shown) of the second polarizer P2. In the embodiment, the polarizer P of the two polarizers P closer to the polarized type viewing angle control device14serves as the first polarizer P1inFIG. 1A. Accordingly, the polarized type viewing angle control device14may omit one polarizer. However, the invention is not limited thereto. In another embodiment, the polarized type viewing angle control device14ofFIG. 6may also adopt the polarized type viewing angle control device100ofFIG. 1A, the polarized type viewing angle control device200ofFIG. 2, the polarized type viewing angle control device300ofFIG. 3, the polarized type viewing angle control device400ofFIG. 4, or the polarized type viewing angle control device500ofFIG. 5. Moreover, the polarized type viewing angle control device14ofFIG. 6may further includes the adhesive layer AD ofFIG. 2, the third polarizer P3ofFIG. 3, the compensation film C ofFIG. 4, or the two compensation films C ofFIG. 5.

By integrating the polarized type viewing angle control device14and the display module12, an azimuth angle of a display light beam emitted from the polarized type viewing angle control display apparatus10may be limited. Accordingly, the polarized type viewing angle display apparatus10has an anti-peep effect. Besides, since the polarized type viewing angle control device14does not control the viewing angle by using a periodic structure, Moiré patterns may be avoided.

FIG. 7is a schematic cross-sectional view illustrating a polarized type viewing angle control display apparatus according to a second embodiment of the invention. Referring toFIG. 7, a polarized type viewing angle control display apparatus20is similar to the polarized type viewing angle control display apparatus10inFIG. 6, so like or similar components are referred to by like or similar reference symbols and detailed descriptions thereof will not be repeated in the following.

The polarized type viewing angle control display apparatus20mainly differs from the polarized type viewing angle control display apparatus10ofFIG. 6in the following way. In the polarized type viewing angle control display apparatus10ofFIG. 6, the polarized viewing angle control device14is located between the display module12and the light source module BL. In the polarized type viewing angle control display apparatus20ofFIG. 7, the display module12is located between the polarized type viewing angle control device14and the light source module BL. Similar to the polarized type viewing angle control display apparatus10inFIG. 6, in the polarized type viewing angle control apparatus20, the polarizer P of the two polarizers P closer to the polarized type viewing angle control device14serves as the first polarizer P1inFIG. 1A. Accordingly, the polarized type viewing angle control device14may omit one polarizer. However, the invention is not limited thereto. In another embodiment, the polarized type viewing angle control device14ofFIG. 7may also adopt the polarized type viewing angle control device100ofFIG. 1A, the polarized type viewing angle control device200ofFIG. 2, the polarized type viewing angle control device300ofFIG. 3, the polarized type viewing angle control device400ofFIG. 4, or the polarized type viewing angle control device500ofFIG. 5.

In addition, inFIG. 7, the first polarizer P1, the first O-plate compensation film O1, the second O-plate compensation film O2, and the second polarizer P2are arranged in an order reversed from the order shown inFIG. 6. Besides, the polarized type viewing angle control device14ofFIG. 7may further include the adhesive layer AD ofFIG. 2, the compensation film C ofFIG. 4, or the two compensation films C ofFIG. 5. In an embodiment, in addition to the second polarizer P2, the polarized type viewing angle control device14may further include a third polarizer (not shown). The third polarizer is disposed on a surface of the first O-plate compensation film O1facing toward the display module12, and the third polarizer is located between the first O-plate compensation film O1and the first polarizer P1. In addition, a transmission axis of the third polarizer is parallel to the transmission axis (not shown) of the first polarizer P1and the transmission axis (not shown) of the second polarizer P2. For example, the third polarizer may be a reflective polarizer. However, the invention is not limited thereto.

FIG. 8is a schematic cross-sectional view illustrating a polarized type viewing angle control light source module according to an embodiment of the invention. A polarized type viewing angle control light source module30of the embodiment includes a light source module BL and the polarized type viewing angle control device100. The light source module BL may be a direct light source module or a side type light source module. The polarized viewing angle control device100is disposed at a light emitting side of the light source module BL. In another embodiment, the polarized viewing angle control device100may also be replaced by the polarized viewing angle control device200ofFIG. 2, the polarized viewing angle control device300ofFIG. 3, the polarized viewing angle control device400ofFIG. 4, or the polarized viewing angle control device500ofFIG. 5.

By disposing the polarized type viewing angle control device100at the light emitting side of the light source module BL, an azimuth angle of an illumination light beam emitted from the polarized type viewing angle control light source module30is limited. Accordingly, the polarized type viewing angle control light source module30is applicable to an apparatus with a limited viewing angle.

In view of the foregoing, the embodiments of the invention have at least one of the following advantages or effects. In the polarized type viewing angle control device, the polarized type viewing angle control display apparatus, and the polarized type viewing angle control light source module according to the embodiments of the invention, the required phase retardation value is provided by two O-plate compensation films together with two polarizers, so as to limit the viewing angle at the azimuth angle to be controlled. Since the polarized type viewing angle control device does not control the viewing angle by using a periodic structure, Moiré patterns may be avoided. Compared with known products, such as a light control film, the polarized viewing angle control device has a higher luminance from a center view, a lower cost, and a thinner thickness. By limiting the viewing angle in a single direction (e.g., lengthwise or widthwise direction), the polarized type viewing angle control device may be applied in a full anti-peep display or a vehicle display. In an embodiment, the polarized type viewing angle control device may further include a third polarizer or at least one compensation film to facilitate the anti-peep effect.