TWI570465B - Front light module and display module - Google Patents

Description

Front light module and display module

The present invention relates to an optical module and a display module, and more particularly to a front light module and a display module.

Generally, the reflective display design is to stick the light guide plate above the display module and set the light source on the side of the light guide plate. The light emitted by the light source is allowed to travel in total reflection in the light guide plate, and the total reflection behavior is destroyed by the microstructure in the visible region, and is refracted toward the display module. Light refracted to the display module can then be reflected by the display module to be communicated to the viewer.

At present, a Light-Emitting Diode (LED) emits a yellow phosphor by a blue-emitting diode chip, and a white light is produced by mixing blue light and excited yellow light. . The blue and yellow light have different divergence angles. In general, blue light is emitted by the wafer and reflected out of the packaged cup, and its light emission divergence angle is small. Yellow light is generated by the excitation of fluorescent powder, and its divergence angle is large.

Due to the difference in the divergence angle between the blue light band and the yellow light band, and the natural stacking design of the reflective front light module and the market demand for light and thin products, the light coupling area must be shortened. In front of the light source of the general reflective display, since the divergence angle of the yellow light is large, it is easier to enter the display module without entering the visible area, that is, the optical module is absorbed into the display module, so that part of the yellow light is absorbed, so that the visible area is visible. It is easy to present a relatively cool image near the front of the light source. In addition, the overall front light divergence angle (including the blue light divergence angle and the yellow light divergence angle) of the light source is smaller than the front of the light source and is not easy to emit light, so that the ratio of the yellow light that is absorbed into the visible area is greatly reduced, so that the ratio is greatly reduced. A relatively warm white image is easily displayed in the visible area near the front side of the light source. Therefore, there is a problem that the light-emitting color is uneven in the light guide plate near the end of the light source.

Embodiments of the present invention provide a front light module that can make a color of a light source close to the light incident side uniform.

Embodiments of the present invention provide a display module in which a color of a display screen close to a light incident side is uniform.

An embodiment of the present invention provides a front light module including a light guide plate and a light source. The light guide plate includes a first surface, a second surface, and a light incident surface. The second surface is opposite the first surface. The light incident surface abuts the first surface and the second surface. The light-in mask has an area adjacent to the first surface and the second surface. The light source is disposed beside the light incident surface to illuminate the light guide plate. This region forms a first angle with the optical axis of the light source. The first angle is less than 90 degrees.

In an embodiment of the invention, the first included angle is between 50 and 85 degrees.

In an embodiment of the invention, the second surface is parallel to the optical axis of the light source. The light incident surface forms a second angle with the second surface. The second angle is between 50 and 85 degrees.

In an embodiment of the invention, the first surface is substantially parallel to the second surface.

In an embodiment of the invention, the light source is a Light-Emitting Diode (LED).

In an embodiment of the invention, the light incident surface is a flat surface.

In an embodiment of the invention, the light incident surface includes a first microstructure that protrudes or is recessed on the light incident surface. The first microstructure includes an area.

In an embodiment of the invention, the shape of the first microstructure is a part of a cylindrical shape, a part of a prismatic shape or a part of a conical shape.

In an embodiment of the invention, the light incident surface further includes a second microstructure that protrudes or is recessed on the light incident surface. The second microstructure includes another region. The first microstructure is staggered in a row with the second microstructure. The shape of the first microstructure is a part of a conical shape, the apex of the cone is connected to the first surface, and the bottom surface of the cone is connected to the second surface. The shape of the second microstructure is a part of a conical shape, the apex of the cone is connected to the second surface, and the bottom surface of the cone is connected to the first surface.

In an embodiment of the invention, the first microstructure is a plurality of first microstructures. These first microstructures are connected or not connected to each other.

An embodiment of the invention provides a display module including a reflective display panel, a light guide plate, and a light source. The light guide plate is disposed on the reflective display panel. The light guide plate includes a first surface, a second surface, and a light incident surface. The second surface is opposite the first surface. One of the first surface and the second surface faces the reflective display panel and the other faces away from the reflective display panel. The light incident surface abuts the first surface and the second surface. The light-in mask has an area adjacent to the first surface and the second surface. The light source is disposed beside the light incident surface to illuminate the light guide plate. This region forms a first angle with the optical axis of the light source. The first angle is less than 90 degrees.

In an embodiment of the invention, the display module further includes an adhesive layer disposed between the reflective display panel and the light guide plate for fixing the reflective display panel and the light guide plate. The refractive index of the adhesive layer is smaller than the refractive index of the light guide plate.

In an embodiment of the invention, one of the first surface and the second surface facing the reflective display panel comprises a plurality of microstructures. The microstructures are convex or concavely disposed on one of the first surface and the second surface.

Based on the above, the light-input mask of the light guide plate of the front light module of the embodiment of the present invention has a region adjacent to the first surface and the second surface of the light guide plate. This region forms a first angle with the optical axis of the light source. The first angle is less than 90 degrees. Therefore, the front light module can make the color of one light source close to the light incident side uniform. In addition, the light-input mask of the light guide plate of the display module of the embodiment of the invention has a region adjacent to the first surface and the second surface of the light guide plate. This region forms a first angle with the optical axis of the light source. The first angle is less than 90 degrees. Therefore, the display screen of the display module is uniform in color near the light entrance side.

In order to make the above features and advantages of the present invention more apparent, the following is a special The embodiments are described in detail below in conjunction with the drawings.

100, 100'‧‧‧ front light module

110, 310, 410a, 410b, 410c, 410d, 410e, 410f, 410g, 410h‧‧‧ light guide

112a, 112b, 112c, 112d, 112e, 112f, 112g, 112h‧‧‧ first microstructure

114f, 114g, 114h‧‧‧ second microstructure

120‧‧‧Light source

122‧‧‧Lighting chip

124‧‧‧ wavelength conversion substances

126‧‧‧Shell

200, 300‧‧‧ display module

210‧‧‧Reflective display panel

220‧‧‧Adhesive layer

222‧‧‧Microstructure

A‧‧‧ part of the non-visible area

BL, BL’‧‧‧Blue

BLrf’‧‧‧ incident blue light

BLtrl’‧‧‧Full Reflection Blu-ray

BL θ ‧‧‧Blu-ray divergence angle

D1, d2, d3‧‧‧ distance

YL, YL’‧‧‧ Huang Guang

YLrf’‧‧‧ incident yellow light

YLtrl’‧‧‧Full Reflection Yellow Light

YL θ ‧‧‧Yellow light divergence angle

IS, IS', ISa, ISb, ISc, ISd, IShe, ISf, ISg, ISh, ISb‧‧‧

ISA, ISAb, ISAc, ISAd, ISAe, ISAf, ISAG, ISAH, ISAi, ISAj, ISAK‧‧‧ Area

Lines I-I, II-II, III-III‧‧

OA‧‧‧ optical axis

S1‧‧‧ first surface

S2‧‧‧ second surface

Sec1, Sec2‧‧‧ facets

SLC‧‧‧Light cone

θ 1‧‧‧ first angle

θ 2‧‧‧second angle

VA‧‧ visible area

X‧‧‧X axis

Y‧‧‧Y axis

Z‧‧‧Z axis

1 is a side elevational view of an optical module prior to an embodiment of the present invention.

2A is a side elevational view of a display module in accordance with an embodiment of the present invention.

Fig. 2B is a light emission spectrum of the light emitting diode element of the embodiment of Fig. 2A.

2C is a schematic view showing the light emitting direction of the blue light portion of the light emitting diode element of the embodiment of FIG. 2A.

Fig. 2D is a schematic view showing the light emitting direction of the yellow light portion of the light emitting diode element of the embodiment of Fig. 2A.

2E is a top plan view of the display module of the embodiment of FIG. 2A.

2F to 2G are optical divergence simulation diagrams of the light source of the embodiment of Fig. 2A at different angles.

2H is a cross-sectional view of the display module of the embodiment of FIG. 2A taken along line I-I of the light source of FIG. 2F.

2I is a cross-sectional view of the display module of the embodiment of FIG. 2A taken along line II-II of the light source of FIG. 2F.

3A is a side elevational view of a display module in accordance with a comparative embodiment of the present invention.

3B is a cross-sectional view of the display module of the embodiment of FIG. 3A taken along line I-I of the light source of FIG. 2F.

3C is a view showing the display module of the embodiment of FIG. 3A along line II-II of the light source of FIG. 2F. Schematic diagram of the section.

4A is a perspective view of a light guide plate of a light module before another embodiment of the present invention.

4B is a top plan view of the light guide plate of the embodiment of FIG. 4A.

4C is a side elevational view of the light guide plate of the embodiment of FIG. 4A.

5A is a perspective view of a light guide plate of a light module before another embodiment of the present invention.

FIG. 5B is a top view of the light guide plate of the embodiment of FIG. 5A. FIG.

Figure 5C is a side elevational view of the light guide of the embodiment of Figure 5A.

6A to 6F are perspective views of a light guide plate of a light module before other embodiments of the present invention.

1 is a side elevational view of an optical module prior to an embodiment of the present invention. Please refer to FIG. 1. In this embodiment, the front light module 100 includes a light guide plate 110 and a light source 120. The light guide plate 110 includes a first surface S1, a second surface S2, and a light incident surface IS. The second surface S2 is opposite to the first surface S1. The light incident surface IS is adjacent to the first surface S1 and the second surface S2. The light incident surface IS has a region ISA adjacent to the first surface S1 and the second surface S2. Specifically, the first surface S1 is substantially parallel to the second surface S2. However, in another embodiment, the first surface S1 and the second surface S2 may also be non-parallel. In addition, the light incident surface IS of this embodiment is a flat surface. However, in another embodiment, the light incident surface IS can also be, for example, a concave surface or a convex surface. At the same time, the light entrance surface IS can be exemplified If it is a curved surface, a circular arc surface, a paraboloid or a free curved surface, the invention is not limited thereto.

In the present embodiment, the area ISA is an extension between the first surface S1 and the second surface S2. That is, the first surface S1, the area ISA, and the second surface S2 of the present embodiment are continuous. In other embodiments, the area ISA may also be, for example, a portion of the extension between the first surface S1 and the second surface S2. That is, the first surface S1, the area ISA, and the second surface S2 may be, for example, discontinuous. Further, in the present embodiment, the area ISA is the entire surface of the light incident surface IS. In another embodiment, the light-incident surface IS can also have a plurality of regions ISA, which can be, for example, connected to each other or separated from one another. In addition, the area ISA can be, for example, an integral surface that occupies the light-incident surface IS, or can be, for example, a part of the surface that occupies the light-incident surface IS, and the invention is not limited thereto.

In this embodiment, the light source 120 is disposed adjacent to the light incident surface IS for illuminating the light guide plate 110. The area ISA forms a first angle θ 1 with the optical axis OA of the light source 120. The first angle θ 1 is less than 90 degrees. Specifically, the first included angle θ 1 is between 50 and 85 degrees. More preferably, the first angle θ 1 is between 70 and 80 degrees. In addition, in the embodiment, the light incident surface IS forms a second angle θ 2 with the second surface S2, and the second angle θ 2 is less than 90 degrees. Specifically, the second included angle θ 2 is between 50 and 85 degrees. More preferably, the second included angle θ 2 is between 70 and 80 degrees. In the present embodiment, the second surface S2 is parallel to the optical axis OA of the light source 120. That is to say, the light emitted from the light source 120 is incident horizontally into the light guide plate 110. In other embodiments, however, the second surface S2 and the optical axis OA of the light source 120 may also be non-parallel. That is to say, the light emitted by the light source 120 may also be incident on the light guide plate 110 not horizontally. In addition, there may be a gap between the light source 120 and the light guide plate 110, or may be in contact with each other. In addition, in this embodiment, the light source 120 of the front light module 100 is a Light-Emitting Diode (LED) component, which may be, for example, a light-emitting diode component including a single light-emitting diode chip. It may be a light emitting diode element comprising a plurality of light emitting diode wafers. In other embodiments, the light source 120 of the front light module 100 may also be other light sources, or a combination of different light sources, and the invention is not limited thereto.

2A is a side elevational view of a display module in accordance with an embodiment of the present invention. Please refer to FIG. 2A. In the embodiment, the display module 200 includes a reflective display panel 210, a light guide plate 110, and a light source 120. The light guide plate 110 is disposed on the reflective display panel 210. The arrangement of the light guide plate 110 and the light source 120 is the same as that of the optical module 100 before the embodiment of FIG. 1 described above. For the description of the light guide plate 110 and the light source 120, reference may be made to the related descriptions of the light guide plate 110 and the light source 120 of the front light module 100 of the embodiment of the present invention, and details are not described herein again. In this embodiment, the display module 200 can be regarded as being in a space constructed by the X-axis, the Y-axis, and the Z-axis, wherein the X-axis direction is substantially parallel to the optical axis OA direction of the light source 120, and extends in the horizontal direction. . The Z-axis direction is perpendicular to the X-axis direction and extends in the vertical direction. In addition, the Y-axis direction is perpendicular to the X-axis direction and perpendicular to the Z-axis direction.

In the present embodiment, one of the first surface S1 and the second surface S2 of the light guide plate 110 faces the reflective display panel 210, and the other faces away from the reflective display panel 210. Specifically, the second surface S2 faces the reflective display panel 210, and the first surface S1 faces away from the reflective display panel 210. In addition, in this embodiment, the display The module 200 further includes an adhesive layer 220 disposed between the reflective display panel 210 and the light guide plate 110 for fixing the reflective display panel 210 and the light guide plate 110. Specifically, the refractive index of the adhesive layer 220 is smaller than the refractive index of the light guide plate 110. The material of the adhesive layer 220 may be, for example, Optically Clear Adhesive (OCA), or other kinds of adhesive materials. In addition to this, one of the first surface S1 and the second surface S2 facing the reflective display panel 210 includes a plurality of microstructures 222. The microstructures 222 are convex or concavely disposed on at least one of the first surface S1 and the second surface S2.

In the present embodiment, the second surface S2 facing the reflective display panel 210 includes a plurality of microstructures 222 that are convexly or concavely disposed on the second surface S2. In particular, the microstructures 222 can be, for example, disposed in a designated area of the second surface S2. In this embodiment, since the refractive index of the adhesive layer 220 is smaller than the refractive index of the light guide plate 110, the light beam emitted from the light source 120 enters the light guide plate 110 from the light incident surface IS of the light guide plate 110, and can be totally reflected in the light guide plate 110. (total reflection) travel. When the light beam traveling in total reflection in the light guide plate 110 enters a visible area of the display module 200 corresponding to the specified area, the total reflection can be destroyed by the microstructures 222, and the light beam originally traveling in the light guide plate 110 can be made. These microstructures 222 of the designated area are refracted toward the direction of the reflective display panel 210. The display module 200 reflects the light beam to the viewer through the reflective display panel 210 to achieve the effect of displaying the screen. Specifically, the shape of the microstructures 222 may be different according to different requirements of the display screen, and the invention is not limited thereto. In addition, in order to clearly show that the microstructure 222 is disposed on the second surface S2, the micro of FIG. 2A Structure 222 is shown in an enlarged scale. In particular, the microstructures 222 and other components are shown to be appropriately sized for clarity of construction and are not intended to limit the size relationship.

FIG. 2B is an emission spectrum of the light emitting diode element of the embodiment of FIG. 2A, please refer to FIG. 2B. In Fig. 2B, the horizontal axis represents the wavelength, the unit is nanometer (nm), and the vertical axis represents the relative emission intensity (Relative Emission Intensity). In general, a white light emitting diode excites a yellow phosphor with a blue light emitting diode chip, and a white light is produced by mixing blue light and yellow light generated by excitation. Therefore, from the light-emitting spectrum of the light-emitting diode element, the portion of the blue-wave spectrum of the shorter wavelength and the portion of the yellow-light spectrum of the longer wavelength can be seen. Specifically, the light source 120 of the embodiment of FIG. 2A may be, for example, the white light emitting diode element of FIG. 2B, or may be a white light emitting diode element of other spectral types. In addition, the light source 120 may also be a red, blue, green or other color light emitting diode element, and the invention is not limited thereto.

2C is a schematic view showing the light emitting direction of the blue light portion of the light emitting diode device of the embodiment of FIG. 2A, and FIG. 2D is a schematic view showing the light emitting direction of the yellow light portion of the light emitting diode device of the embodiment of FIG. 2A. Please refer to FIG. 2C and FIG. 2D. In the present embodiment, the light source 120 is, for example, the white light emitting diode element of FIG. 2B. The light source 120 includes a light emitting chip 122, a wavelength converting substance 124, and a casing 126. The light emitting chip 122 is disposed in a recessed receiving space of the housing 126, and the wavelength converting substance 124 covers the light emitting wafer 122. The light-emitting wafer 122 is, for example, a blue-emitting light-emitting diode wafer, and the wavelength-converting material 124 includes, for example, yellow phosphor powder. The illuminating wafer 122 is used to emit blue light BL, and part of the blue light BL excites the wavelength converting substance 124, such as yellow luminescent powder, so that the excited wavelength converting substance 124 emits yellow light YL outward. In addition, another portion of the blue light BL passes through the wavelength converting substance 124 and is emitted outward. Specifically, the blue light BL emitted from the light emitting diode element and the yellow light YL generated by the excitation are mixed to generate white light. The blue light BL emitted by the light emitting diode element forms a blue light divergence angle BL θ (as shown in FIG. 2C), and at the same time, the yellow light YL emitted by the light emitting diode element forms a yellow light divergence angle YL θ (see FIG. 2D). Shown). Since the blue light BL is emitted by the light emitting chip 122, and part of the lateral blue light BL is reflected by the housing 126, the blue light divergence angle BL θ is significantly narrower than the yellow light divergence angle YL θ . In addition, since the yellow light YL is generated by the excitation of the yellow fluorescent powder, the yellow light divergence angle YL θ is wider than the blue light divergence angle BL θ .

2E is a top view of the display module of the embodiment of FIG. 2A, please refer to FIG. 2E. In this embodiment, the display module 200 includes two light sources 120. The light source 120 is disposed adjacent to the light incident surface IS of the light guide plate 110 for illuminating the light guide plate 110. In other embodiments, the display module 200 can also include a plurality of light sources 120. In particular, a suitable number of light sources 120 can be configured according to display requirements, and the invention is not limited thereto. In this embodiment, the display module 200 includes a viewable area VA. When the light beam traveling in the light guide plate 110 with total reflection enters the visible area VA, it can be refracted in the direction of the reflective display panel 210 by the microstructure 222 of the light guide plate 110. Specifically, the blue light BL and the yellow light YL emitted from the light source 120 enter the light guide plate 110 via the light incident surface IS. The divergence angle of the yellow light YL is larger than the divergence angle of the blue light BL.

2F to 2G are light beams of different angles of the light source of the embodiment of Fig. 2A For the divergence simulation, please refer to Figure 2F and Figure 2G. In the present embodiment, the light cone SLC simulates, for example, a light cone emitted by the light source 120 to indicate the divergence of light emitted by the light source 120. Specifically, the cross section of the light cone SLC along the line II may indicate the case where the light source 120 emits light in the center. The cross section of the light cone SLC along the line II-II may indicate that the light source 120 is laterally illuminated at a large angle, and the light is emitted. The cross section of the cone SLC along the line III-III may indicate the case where the light source 120 is laterally illuminated at a small angle. Comparing the difference in the cross section of the light cone SLC along the I-I line, the II-II line, and the III-III line, it is possible to understand the light-emitting state of the light source 120 in the center and the lateral direction. In the present embodiment, the light source 120 is emitted at the fixed section Sec1. The light source 120 emits light at the center of the light cone SLC formed by lateral light emission of the light source 120, and forms different light divergence widths on the cut surface Sec2. Specifically, the light divergence width of the light cone SLC along the line II corresponds to the divergence width of the cut surface Sec2 is d1, and the cross section of the light cone SLC along the line II-II corresponds to the light divergence width of the cut surface Sec2 is d2. The section of the light cone SLC along the line III-III corresponds to a light divergence width on the section Sec2 of d3. In the present embodiment, since the light source 120 emits light at a substantially central center with a degree of light divergence greater than that of the light source 120 in the lateral direction, d1>d3>d2. However, in other embodiments, the light divergence design of the light source may be different, and the degree of light divergence of the light source in the positive center and the light divergence of the light source in the lateral light are different from the size relationship of the embodiment. It is not limited to this.

2H is a cross-sectional view of the display module of the embodiment of FIG. 2A taken along line II of the light source of FIG. 2F. 2H illustrates the display module 200 corresponding to the non-visible area A of the portion of FIG. 2A and FIG. 2E, and a portion of the non-visible area A is not located in the visible area VA, please refer to FIG. 2H. In the present embodiment, since the second included angle θ 2 formed by the light incident surface IS and the second surface S2 is less than 90 degrees, the light incident surface IS is inclined toward the second surface S2. The light incident horizontally by the light source 120 is deflected toward the second surface S2 after passing through the light incident surface IS inclined toward the second surface S2. Specifically, after the blue light BL' and the yellow light YL' emitted by the light source 120 enter the light incident surface IS of the light guide plate 110, they are deflected toward the second surface S2. At the same time, the blue light BL' and the yellow light YL' diverge in the light guide plate 110 at different divergence angles.

In the present embodiment, the divergence angle of the yellow light YL' diverging in the light guide plate 110 is larger than the divergence angle of the blue light BL' diverging in the light guide plate 110. Part of the yellow light YL' is refracted into the adhesive layer 220 to form incident yellow light YLrf'. Further, part of the yellow light YL' forms a total reflection yellow light YLtrl' because the incident angle incident on the adhesive layer 220 is larger than the critical angle. In contrast, in the present embodiment, part of the blue light BL' forms the incident blue light BLrf', and part of the blue light BL' forms the total reflection blue light BLtrl'. Specifically, the incident yellow light YLrf' and the incident blue light BLrf' are at least partially absorbed by the adhesive layer 220 after entering the adhesive layer 220, and it is difficult to travel to the light guide plate 110 by total reflection. In addition, the total reflection yellow light YLtrl' and the total reflection blue light BLtrl' are caused to travel through the light guide plate 110 by total reflection, and enter the position of the light guide plate 110 corresponding to the visible area VA of the display module 200. Then, the total reflection yellow light YLtrl' and the total reflection blue light BLtrl' are refracted in the direction of the reflective display panel 210 through the microstructure 222 located at the position of the light guide plate 110. The display module 200 reflects the light beam to the viewer through the reflective display panel 210 to achieve the effect of displaying the screen.

In this embodiment, although the yellow light divergence angle YLθ of the light source 120 is greater than blue Light divergence angle BLθ, but the ratio of incident yellow YLrf' to yellow light YL' is close to the ratio of incident blue light BLrf' to blue light BL', and the ratio of total reflection yellow YLtrl' to yellow light YL' and total reflection blue light The ratio of BLtrl' to Blu-ray BL' is close. Therefore, the image displayed in the visible area VA of the display module 200 directly in front of the light source 120 is not warm white or cool white.

2I is a cross-sectional view of the display module of the embodiment of FIG. 2A taken along line II-II of the light source of FIG. 2F. Similar to FIG. 2H, FIG. 2I also shows that the display module 200 corresponds to the non-visible area A of the parts of FIG. 2A and FIG. 2E, and part of the non-visible area A is not located in the visible area VA, please refer to FIG. In the present embodiment, since the second included angle θ 2 formed by the light incident surface IS and the second surface S2 is less than 90 degrees, the light incident surface IS is inclined toward the second surface S2. The light incident horizontally by the light source 120 is deflected toward the second surface S2 after passing through the light incident surface IS inclined toward the second surface S2. Specifically, the blue light BL' and the yellow light YL' enter the light incident surface IS of the light guide plate 110, are deflected toward the second surface S2, and are diverged in the light guide plate 110 at different divergence angles.

In the present embodiment, the light source 120 emits light at a center that is more divergent than the light source 120 emits light in a lateral direction. Therefore, the blue light divergence angle and the yellow light divergence angle of the light source 120 corresponding to the lateral light emission are respectively smaller than the blue light divergence angle and the yellow light divergence angle of the light source 120 corresponding to the positive center light emission. Specifically, in the case where the light source 120 of FIG. 2I emits light laterally, the divergence angle of the yellow light YL' diverging in the light guide plate 110 is also larger than the divergence angle of the blue light BL' diverging in the light guide plate 110. Further, as in the case where the light source 120 of Fig. 2H emits light in the center, part of the yellow light YL' also forms incident yellow YLrf' and total reflection yellow YLtrl', and part of the blue BL' shape The incident blue light BLrf' and the total reflection blue light BLtrl'.

In the present embodiment, although the yellow light divergence angle YLθ of the light source 120 is greater than the blue light divergence angle BLθ, in the case where the light source 120 emits light laterally, the ratio of the incident yellow light YLrf' to the yellow light YL' and the incident blue light BLrf' The ratio of the blue light BL' is close, and the ratio of the total reflection yellow light YLtrl' to the yellow light YL' is close to the ratio of the total reflection blue light BLtrl' to the blue light BL'. Therefore, the image displayed in the visible area VA of the display module 200 in front of the light source 120 side is not warm white or cool white.

Specifically, the image displayed in the visible area VA of the display module 200 in front of the light source 120 and the front side of the display module 200 is not warm or white, so the display module 200 displays the screen near the light entrance side. The color is even. In addition, since the display module 200 uses the light guide plate 110 and the light source 120 of the front light module 100, the front light module 100 can make the color of one light source close to the light entrance side uniform, thereby making a display screen close to the light entrance side. The color is even.

3A is a side elevational view of a display module in accordance with a comparative embodiment of the present invention, with reference to FIG. 3A. In the present embodiment, the display module 300 is different from the display module 200 in that the light incident surface IS' of the light guide plate 310 of the display module 300 is a plane perpendicular to the second surface S2. At the same time, the optical axis OA of the light source 120 is perpendicular to the light incident surface IS'. For related descriptions of the remaining components of the display module 300, please refer to the related description of the display module 200, and details are not described herein again.

3B is a cross-sectional view of the display module of the embodiment of FIG. 3A taken along line I-I of the light source of FIG. 2F. FIG. 3B illustrates that the display module 300 corresponds to the non-visible area A of the portion of FIG. 3A, and part of the non-visible area A is not located in the visible area of the display module 300. Among the (not shown), please refer to FIG. 3B. In the present comparative embodiment, the blue light BL'' and the yellow light YL'' emitted by the light source 120 enter the light incident surface IS' of the light guide plate 310 and diverge in the light guide plate 310 at different divergence angles.

In the present comparative embodiment, the divergence angle of the yellow light YL'' diverging in the light guide plate 310 is larger than the divergence angle of the blue light BL'' diverging in the light guide plate 310. In addition, as in the case where the light source 120 of FIG. 2H emits light in the center, a part of the yellow light YL'' forms an incident yellow YLrf'' and a total reflection yellow YLtrl'', and a part of the blue light BL'' forms an incident blue BLrf'. 'And total reflection blue BLtrl''. In the present embodiment, since the yellow light divergence angle YLθ of the light source 120 is greater than the blue light divergence angle BLθ, and the incident surface IS′ of the light guide plate 310 is not inclined toward the second surface S2, the incident yellow light YLrf′′ and the incident blue light are incident. The ratio of BLrf'' is difficult to adjust. Therefore, in the comparative embodiment, the ratio of the incident yellow light YLrf'' to the yellow light YL'' is higher than the ratio of the incident blue light BLrf'' to the blue light BL''. At the same time, the ratio of total reflection yellow light YLtrl'' to yellow light YL'' is lower than the ratio of total reflection blue light BLtrl'' to blue light BL''. Specifically, more blue light BL'' (total reflection blue light BLtrl'') enters the position of the light guide plate 310 corresponding to the visible area (not shown) of the display module 200. Therefore, the image presented in front of the light source 120 in the visible area (not shown) of the display module 300 may be cold white.

3C is a cross-sectional view of the display module of the embodiment of FIG. 3A taken along line II-II of the light source of FIG. 2F. In the present embodiment, FIG. 3C illustrates that the display module 300 corresponds to the non-visible area A of the portion of FIG. 3A, and part of the non-visible area A is not located in the visible area of the display module 300 (not shown). Please refer to Figure 3C. In this comparison In the embodiment, the light source 120 emits light at a positive center with a greater degree of light divergence than the light source 120 emits light in a lateral direction. Therefore, the blue light divergence angle and the yellow light divergence angle of the light source 120 corresponding to the lateral light emission are respectively smaller than the blue light divergence angle and the yellow light divergence angle of the light source 120 corresponding to the positive center light emission. Specifically, in the case where the light source 120 of FIG. 3C emits light laterally, the divergence angle of the yellow light YL'' diverging in the light guide plate 310 is also larger than the divergence angle of the blue light BL'' diverging in the light guide plate 310. In addition, as in the case where the light source 120 of FIG. 3B emits light in the center, part of the yellow light YL'' also forms incident yellow YLrf'' and total reflection yellow YLtrl'', and part of the blue light BL'' forms incident blue BLrf' 'And total reflection blue BLtrl''.

In the present embodiment, since the yellow light divergence angle YLθ of the light source 120 is greater than the blue light divergence angle BLθ, and the incident surface IS′ of the light guide plate 310 is not inclined toward the second surface S2, the incident yellow light YLrf′′ and the incident blue light are incident. The ratio of BLrf'' is difficult to adjust. Therefore, in the present comparative embodiment, the ratio of the incident yellow light YLrf'' to the yellow light YL'' is lower than the ratio of the incident blue light BLrf'' to the blue light BL''. At the same time, the ratio of the total reflection yellow light YLtrl'' to the yellow light YL'' is higher than the ratio of the total reflection blue light BLtrl'' to the blue light BL''. Specifically, a plurality of yellow light YL'' (total reflection yellow light YLtrl') enters the position of the light guide plate 310 corresponding to the visible area (not shown) of the display module 200. Therefore, the image presented in front of the light source 120 in the visible area (not shown) of the display module 300 may be warmer white.

Specifically, the image displayed in the visible area (not shown) of the display module 300 of the present embodiment is close to the front of the light source 120, and the image of the display module 300 is not visible in the visible area (not shown). The image presented in front of the side of the light source 120 will The display module 300 of the comparative embodiment displays the color unevenness of the screen near the light incident side.

Referring to FIG. 2A again, since FIG. 2A shows that the region ISA of the light incident surface IS of the light guide plate 110 of the module 200 forms a first angle θ1 with the optical axis OA of the light source 120, the first angle θ1 is less than 90 degrees. After the blue light BL' and the yellow light YL' emitted by the light source 120 enter the light incident surface IS of the light guide plate 110, they are deflected toward the second surface S2. Specifically, the degree to which the blue light BL' and the yellow light YL' are deflected toward the second surface S2 is inconsistent. Therefore, in the light guide plate 110 is directly in front of the light source 120, the ratio of the incident yellow light YLrf's to the yellow light YL' is adjusted to be close to or the same as the ratio of the incident blue light BLrf' to the blue light BL', and the total reflection yellow light YLtrl' The ratio of the light YL' to the ratio of the total reflection blue light BLtrl' to the blue light BL' is also adjusted to be close to or the same. Similarly, the light guide plate 110 is close to the front side of the light source 120, the ratio of the incident yellow light YLrf's to the yellow light YL' is adjusted to be close to or the same as the ratio of the incident blue light BLrf' to the blue light BL', and the total reflection yellow light YLtrl' The ratio of the light YL' to the ratio of the total reflection blue light BLtrl' to the blue light BL' is also adjusted to be close to or the same. Therefore, the image displayed in the visible area VA of the display module 200 in front of the light source 120 and the front side is not warm or white, so that the color of the display module 200 on the light-incident side is uniform.

4A is a perspective view of a light guide plate of an optical module according to another embodiment of the present invention, FIG. 4B is a top view of the light guide plate of the embodiment of FIG. 4A, and FIG. 4C is a side view of the light guide plate of the embodiment of FIG. 4A. Please refer to Figures 4A to 4C. In this embodiment, the light guide plate 410a is similar to the light guide plate 110 of the embodiment of FIG. 2A. Related components and functions of the light guide plate 410a may refer to the related description of the light guide plate 110. Let me repeat. The light guide plate 410a is different from the light guide plate 110 in that the light incident surface ISa of the light guide plate 410a includes at least one first microstructure 112a protruding or recessed on the light incident surface ISa. The first microstructure 112a includes a region ISAa, and the region ISAa abuts the first surface S1 and the second surface S2. Specifically, the light guide plate 410a includes a plurality of first microstructures 112a, and the first microstructures 112a are semi-cylindrical in shape, and the first microstructures 112a protrude from the light incident surface ISa. However, in some embodiments, the shape of the first microstructures 112a may also be a part of a cylinder, a part of a prismatic shape or a part of a conical shape, and the first microstructures 112a are convex or concave on the light incident surface ISa. Further, in the present embodiment, each of the adjacent two first microstructures 112a is connected to each other. In other embodiments, however, each of the two adjacent first microstructures may also be unconnected. In addition, in some embodiments, the light incident surface of the light guide plate may also include only one first microstructure, which is convex or concave on the light incident surface, and the invention is not limited thereto.

5A is a perspective view of a light guide plate of an optical module according to another embodiment of the present invention, FIG. 5B is a top view of the light guide plate of the embodiment of FIG. 5A, and FIG. 5C is a side view of the light guide plate of the embodiment of FIG. 5A. Please refer to Figures 5A to 5C. In the present embodiment, the light guide plate 410b is similar to the light guide plate 410a of the embodiment of FIG. 4A. The related components and functions of the light guide plate 410b can be referred to the related description of the light guide plate 410a, and details are not described herein again. The light guide plate 410b is different from the light guide plate 410a in that the shape of the plurality of first microstructures 112b of the light incident surface ISb of the light guide plate 410b is a part of a prismatic shape, and the first microstructures 112b protrude from the light entrance surface. ISb. The first microstructure 112b includes a region ISAb, and the region ISAb abuts the first surface S1 and the second surface S2.

Specifically, the light guide plate 410a of the embodiment of FIG. 4A can be applied to at least the optical module 100 before FIG. 1 and the display module 200 of FIG. 2A. In addition, the light guide plate 410b of the embodiment of FIG. 5A can also be applied to at least the optical module 100 before FIG. 1 and the display module 200 of FIG. 2A. In these embodiments, since the surface area of the guide plate 410a of the ISAa ISa first angle [theta] formed with the optical axis OA 1 of the light source 120, the first angle [theta] 1 is less than 90 degrees. Therefore, after the blue light and the yellow light emitted from the light source 120 enter the light incident surface ISa of the light guide plate 410a, they are deflected toward the second surface S2. Likewise, since the surface area of the light guide plate 410b ISb ISAb the first angle [theta] formed with the optical axis OA 1 of the light source 120, the first angle [theta] 1 is less than 90 degrees. Therefore, the blue light and the yellow light emitted from the light source 120 enter the light incident surface ISb of the light guide plate 410b, and are deflected toward the second surface S2. Therefore, in these embodiments, the light guide plate 410a and the light guide plate 410b have an effect similar to the light guide plate 110 deflecting light. Specifically, the front light module of the light guide plate 410a or the light guide plate 410b can make the color of one light source close to the light incident side uniform, and even the color of a display screen close to the light incident side is uniform. In addition, the display module using the light guide plate 410a or the light guide plate 410b has a uniform color on the display screen near the light incident side.

6A to 6F are schematic perspective views of a light guide plate of an optical module before other embodiments of the present invention. Please refer to FIG. 6A and FIG. 6B first. In this embodiment, the light guide plate 410c and the light guide plate 410d are similar to the light guide plate 410a of the embodiment of FIG. 4A. The related components and functions of the light guide plate 410c and the light guide plate 410d can be referred to the related description of the light guide plate 410a. Narration. The light guide plate 410c and the light guide plate 410d are different from the light guide plate 410a in that the light guide plate 410c and the light guide plate 410d are different. The plurality of first microstructures 112c, 112d of the light incident surfaces ISc, ISd have a conical shape, and the first microstructures 112c, 112d protrude from the light incident surfaces ISc, ISd, respectively. In addition, the first microstructures 112c, 112d respectively include a region ISAc, ISAd, and the region ISAc and the region ISAd are adjacent to the first surface S1 and the second surface S2. In some embodiments, the first microstructures 112c, 112d are shaped as a portion of a conical shape, while the conical apex is coupled to the first surface S1 and the conical bottom surface is coupled to the second surface S2. In other embodiments, the apex of the cone may be connected to the second surface S2, and the bottom surface of the cone is connected to the first surface S1, and the invention is not limited thereto. Specifically, the light guide plate 410c and the light guide plate 410d can be applied to at least the front light module 100 and the display module 200, and have functions similar to the light guide plates 110, 410a, and 410b.

Next, referring to FIG. 6C, in the present embodiment, the light guide plate 410e is similar to the light guide plate 410d of FIG. 6B. The light guide plate 410e is different from the light guide plate 410d in that the shape of the plurality of first microstructures 112e of the light incident surface ISe of the light guide plate 410e is a part of a conical shape, and the apex of the cone is connected with the second surface S2, and the bottom surface of the cone is A surface S1 is connected. In addition, these first microstructures 112e are recessed in the light incident surface ISe. The first microstructure 112e includes a region ISAe, and the region ISAe abuts the first surface S1 and the second surface S2. Specifically, the light guide plate 410e can be applied to at least the front light module 100 and the display module 200, and has functions similar to the light guide plates 110, 410a, 410b, 410c, and 410d.

Referring to FIG. 6D, in the embodiment, the light guide plate 410f is similar to the light guide plate 410d of FIG. 6B. Related components and functions of the light guide plate 410f can be referred to the light guide plate. The related description of 410d will not be repeated here. The light guide plate 410f is different from the light guide plate 410d in that the light incident surface ISf of the light guide plate 410f includes a plurality of first microstructures 112f protruding from the light incident surface ISf. The first microstructure 112f includes a region ISAf, and the region ISAf abuts the first surface S1 and the second surface S2. In addition, the light incident surface ISf of the light guide plate 410f further includes a plurality of second microstructures 114f protruding from the light incident surface ISf. The second microstructure includes 114f including another region ISAg. In this embodiment, the plurality of first microstructures 112f and the plurality of second microstructures 114f are staggered in a row. The shape of the first microstructures 112f is a part of a conical shape, the apex of the cone is connected to the first surface S1, and the bottom surface of the cone is connected to the second surface S2. In addition, the shape of the second microstructures 114f is also a part of a conical shape, the apex of the cone is connected to the second surface S2, and the bottom surface of the cone is connected to the first surface S1.

Continuing to refer to FIG. 6D, in some embodiments, the shape of the first microstructure 112f and the second microstructure 114f may also be a part of a cylinder, a part of a prismatic shape or other shapes, and the first microstructure 112f and the The two microstructures 114f may be convex or concave on the light incident surface ISa, and the invention is not limited thereto. In addition, in other embodiments, the adjacent first microstructures 112f and the second microstructures 114f may or may not be connected to each other, and the present invention is not limited thereto. Specifically, the light guide plate 410f can be applied to at least the front light module 100 and the display module 200, and has functions similar to the light guide plates 110, 410a, 410b, 410c, 410d, and 410e.

Next, referring to FIG. 6E, in the present embodiment, the light guide plate 410g is similar to the light guide plate 410f of FIG. 6D. The difference between the light guide plate 410g and the light guide plate 410f is that The plurality of first microstructures 112g of the light incident surface ISg of the light guide plate 410g are recessed on the light incident surface ISg. The first microstructure 112g includes a region ISAh, and the region ISAh abuts the first surface S1 and the second surface S2. Further, the plurality of second microstructures 114g of the light incident surface ISg of the light guide plate 410g are recessed on the light incident surface ISg. The second microstructure 114g includes a region ISAi, and the region ISAi abuts the first surface S1 and the second surface S2. Specifically, the light guide plate 410g can be applied to at least the front light module 100 and the display module 200, and has functions similar to the light guide plates 110, 410a, 410b, 410c, 410d, 410e, and 410f.

Referring next to FIG. 6F, in the present embodiment, the light guide plate 410h is similar to the light guide plate 410f of FIG. 6D. The light guide plate 410h is different from the light guide plate 410f in that the shape of the plurality of first microstructures 112h of the light incident surface ISh of the light guide plate 410h is a part of a cylinder, and the first microstructure 112h is convex on the light incident surface ISh. . The first microstructure 112h includes a region ISAj, and the region ISAj abuts the first surface S1 and the second surface S2. In addition, the shape of the plurality of second microstructures 114g of the light incident surface ISg of the light guide plate 410g is also a part of the cylindrical shape, and the second microstructures 114h are recessed on the light incident surface ISh. The second microstructure 114h includes another region ISAk, and the region ISAk abuts the first surface S1 and the second surface S2. Specifically, the light guide plate 410h can be applied to at least the front light module 100 and the display module 200, and has functions similar to the light guide plates 110, 410a, 410b, 410c, 410d, 410e, 410f, and 410g.

In summary, the light incident surface of the light guide plate of the front light module of the embodiment of the present invention has at least one region adjacent to the first surface and the second surface of the light guide plate. At least one region forms a first angle with the optical axis of the light source. The first angle is less than 90 degrees. Therefore, before The light module can make the color of one light source close to the light-incident side uniform, and even the color of a display screen close to the light-incident side is uniform. In addition, the light incident surface of the light guide plate of the display module of the embodiment of the invention has at least one region adjacent to the first surface and the second surface of the light guide plate. At least one region forms a first angle with the optical axis of the light source. The first angle is less than 90 degrees. Therefore, the display screen of the display module is uniform in color near the light entrance side.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧ front light module

110‧‧‧Light guide plate

120‧‧‧Light source

200‧‧‧ display module

210‧‧‧Reflective display panel

220‧‧‧Adhesive layer

222‧‧‧Microstructure

A‧‧‧ part of the non-visible area

IS‧‧‧Glossy

ISA‧‧‧ area

OA‧‧‧ optical axis

S1‧‧‧ first surface

S2‧‧‧ second surface

θ 1‧‧‧ first angle

θ 2‧‧‧second angle

X‧‧‧X axis

Y‧‧‧Y axis

Z‧‧‧Z axis

Claims (22)

A front light module, comprising: a light guide plate, comprising: a first surface; a second surface opposite to the first surface; and a light incident surface adjacent to the first surface and the second surface, the The light mask has a region adjacent to the first surface and the second surface; and a light source disposed adjacent to the light incident surface for illuminating the light guide plate, wherein the region forms a first angle with the optical axis of the light source The first angle is less than 90 degrees. The front light module of claim 1, wherein the first angle is between 50 and 85 degrees. The front light module of claim 1, wherein the second surface is parallel to the optical axis of the light source, and the light incident surface forms a second angle with the second surface, and the second angle is between 50 To 85 degrees. The front light module of claim 3, wherein the first surface is substantially parallel to the second surface. The front light module of claim 1, wherein the light source is a Light-Emitting Diode (LED). The front light module of claim 1, wherein the light incident surface is a flat surface. The front light module of claim 1, wherein the light incident surface comprises a first microstructure, protruding or recessed on the light incident surface, and the first microstructure comprises an area. The front light module of claim 7, wherein the shape of the first microstructure is a part of a cylindrical shape, a part of a prismatic shape or a part of a conical shape. The front light module of claim 8, wherein the light incident surface further comprises a second microstructure protruding or recessed on the light incident surface, the second microstructure comprising another area, the second microstructure The first microstructure and the second microstructure are staggered in a row, wherein the first microstructure has a shape of a conical portion, the conical apex is connected to the first surface, and the conical bottom surface is connected to the second surface, the second The shape of the microstructure is a part of a conical shape, and the apex of the cone is connected to the second surface, and the bottom surface of the cone is connected to the first surface. The front light module of claim 7, wherein the first microstructure is a plurality of first microstructures, and the first microstructures are connected or not connected to each other. A display module includes: a reflective display panel; a light guide plate disposed on the reflective display panel, the light guide plate comprising: a first surface; a second surface opposite to the first surface One of the surface and the second surface faces the reflective display panel, the other faces away from the reflective display panel; and a light incident surface abuts the first surface and the second surface, the light incident surface Having a region adjacent to the first surface and the second surface; and a light source disposed adjacent to the light incident surface for illuminating the light guide plate, wherein the region forms a first angle with an optical axis of the light source, The first angle is less than 90 degrees. The display module of claim 11, wherein the first included angle is between 50 and 85 degrees. The display module of claim 11, wherein the second surface is parallel to the optical axis of the light source, and the light incident surface forms a second angle with the second surface, the second angle being between 50 and 85 degrees. The display module of claim 13, wherein the first surface is substantially parallel to the second surface. The display module of claim 11, wherein the light source is a Light-Emitting Diode (LED). The display module of claim 11, wherein the light incident surface is a plane. The display module of claim 11, wherein the light incident surface comprises a first microstructure, protruding or recessed on the light incident surface, and the first microstructure comprises an area. The display module of claim 17, wherein the first microstructure has a shape of a part of a cylinder, a part of a prismatic shape or a part of a conical shape. The display module of claim 18, wherein the light incident surface further comprises a second microstructure protruding or recessed on the light incident surface, the second microstructure comprising another region, the first a microstructure and the second microstructure are staggered in a row, wherein the first microstructure is shaped as a part of a conical shape, the conical apex is connected to the first surface, and the conical bottom surface is connected to the second surface, the at least one The shape of the second microstructure is a portion of a conical shape, the apex of the cone is coupled to the second surface, and the bottom surface of the cone is coupled to the first surface. The display module of claim 17, wherein the first microstructure is a plurality of first microstructures, and the first microstructures are connected or not connected to each other. The display module of claim 11, further comprising an adhesive layer disposed between the reflective display panel and the light guide plate for fixing the reflective display panel and the light guide plate, wherein the adhesive layer The refractive index of the layer is less than the refractive index of the light guide plate. The display module of claim 21, wherein one of the first surface and the second surface facing the reflective display panel comprises a plurality of microstructures, the microstructures being convex or concavely disposed One of the first surface and the second surface.