TWI477823B - Light guide and electrophoretic display apparatus switchable between black-white mode and color mode - Google Patents

Description

Light guide plate and electrophoretic display device capable of switching color mode and black and white mode

The invention relates to a light guide plate and an electrophoretic display device capable of switching color mode and black and white mode including the light guide plate

A typical electrophoretic display can only display black and white images and cannot display colorful images. In order to enable electrophoretic displays to render color images, many researchers have attempted to add color filters to electrophoretic displays. However, the pigment in the color filter absorbs about two-thirds of the incident light intensity, which greatly reduces the visual brightness of the electrophoretic display. In addition, such an electrophoretic display can only display color images, and cannot switch between color mode and black and white mode. Therefore, there is a need for a new electrophoretic display device that overcomes the above problems.

One aspect of the present invention provides a light guide plate including a light incident surface and a light exit surface. The light entrance surface is for receiving an incident light. The light exiting surface comprises at least a first region, the first region having a plurality of gratings, the gratings being spaced apart from each other by a distance. Each of the gratings of the first region has a plurality of prisms that extend in a predetermined direction. The predetermined direction of the at least one grating in the first region is different from the predetermined direction of the other grating of the first region, wherein the gratings of the first region cooperate to allow light of a first wavelength range to pass and prevent the other Light passes through the wavelength range.

According to an embodiment of the invention, the gratings comprise at least a first grating and a second grating, the first grating having a plurality of prisms in a first direction Extendingly, the second grating has a plurality of prisms extending in a second direction, the first direction being substantially perpendicular to the second predetermined direction.

According to an embodiment of the invention, the grating further includes a third grating and a fourth grating, the third grating has a plurality of prisms extending in a third direction, and the fourth grating has a plurality of prisms extending in a fourth direction, the third direction The angle between the first direction and the first direction is from about 25 degrees to about 35 degrees, and the angle between the fourth direction and the first direction is from about 55 degrees to about 65 degrees.

According to an embodiment of the invention, the grating further includes a fifth grating and a sixth grating, the fifth grating has a plurality of prisms extending in a fifth direction, and the sixth grating has a plurality of prisms extending in a sixth direction, the fifth direction The angle between the first direction and the first direction is about 115 degrees to about 125 degrees, and the angle between the sixth direction and the first direction is about 145 degrees to about 155 degrees.

According to an embodiment of the invention, the first, second and third gratings are arranged substantially in the same column, and the fourth, fifth and sixth gratings are arranged substantially on the other column.

According to an embodiment of the invention, one edge of the fourth grating and one edge of the second grating are substantially disposed on a straight line, and one edge of the fifth grating and one edge of the third grating are substantially disposed on another straight line.

According to an embodiment of the invention, the prisms of the first grating are arranged at a first pitch, the prisms of the second grating are arranged at a second pitch, and the prisms of the third grating are arranged at a third pitch, and The first pitch is substantially equal to the third pitch, and the first pitch is greater than the second pitch.

According to an embodiment of the invention, the area of each of the gratings is substantially equal.

According to an embodiment of the invention, the gratings are spaced apart from each other by about 1 Μm to about 15 μm.

According to an embodiment of the invention, the prisms are arranged at a pitch of from about 0.2 μm to about 22.3 μm.

According to an embodiment of the invention, the first wavelength range comprises at least one of about 600 nm to about 680 nm, and the other wavelength range comprises at least one of about 500 nm to about 570 nm and about 400 nm to At least one wavelength in about 490 nm.

According to an embodiment of the invention, the first wavelength range comprises at least one wavelength from about 500 nm to about 570 nm, and the other wavelength range comprises at least one of about 600 nm to about 680 nm and about 400 nm to about At least one wavelength in 490 nm.

According to an embodiment of the invention, the first wavelength range comprises at least one wavelength from about 400 nm to about 490 nm, and the other wavelength range comprises at least one of about 600 nm to about 680 nm and about 500 nm to about At least one wavelength in 570 nm.

According to an embodiment of the invention, the light exiting surface further comprises a second region having a plurality of gratings spaced apart from each other by a distance. Each of the gratings of the second region has a plurality of prisms that extend toward a predetermined direction. The predetermined direction of the at least one grating of the second region is different from the predetermined direction of the other grating of the second region, wherein the gratings of the second region cooperate to pass light of a second wavelength range and block another wavelength range Light passes. .

According to an embodiment of the invention, the light exiting surface further comprises a third region having a plurality of gratings spaced apart from each other by a distance. Each of the gratings of the third region has a plurality of prisms that extend toward a predetermined direction. The predetermined direction of the at least one grating of the third region is different from the predetermined one of the other grating of the third region The direction in which the gratings of the third region cooperate to pass light of a third wavelength range and block the passage of light of another wavelength range.

Another aspect of the present invention provides an electrophoretic display device that can switch between a color mode and a black and white mode, which does not include a color filter. The electrophoretic display device comprises an electrophoretic display panel, a light source and a light guide plate. The electrophoretic display panel includes a first sub-pixel, a second sub-pixel, and a third sub-pixel. The light source is used to emit light. The light guide plate includes a light incident surface and a light exit surface. The light entrance surface is used to receive the light emitted by the light source. The light exiting surface includes a first area, a second area, and a third area. The first region has a plurality of gratings spaced apart from each other by a spacing, and the gratings of the first region cooperate to pass light of a first wavelength range and prevent light of another wavelength range from passing. The second region has a plurality of gratings spaced apart from each other by a spacing, and the gratings of the second region cooperate to pass light of a second wavelength range and prevent light of another wavelength range from passing. The third region has a plurality of gratings spaced apart from each other by a spacing, and the gratings of the third region cooperate to pass light of a third wavelength range and prevent light of another wavelength range from passing. When the light source is turned on, the first, second, and third regions respectively project the first, second, and third wavelength ranges of light toward the first, second, and third sub-pixels, so that the electrophoretic display device is in a color mode. When the light source is turned off, the electrophoretic display device is in black and white mode.

According to an embodiment of the invention, each of the gratings of the first region has a plurality of prisms extending in a predetermined direction, and the predetermined direction of the at least one grating of the first region is different from the predetermined direction of the other grating of the first region.

According to an embodiment of the invention, each of the gratings of the second region has a plurality of prisms extending in a predetermined direction, and the predetermined direction of at least one of the gratings of the second region is different from the predetermined direction of the other grating of the second region.

According to an embodiment of the invention, each of the gratings of the third region has a plurality of prisms extending in a predetermined direction, and the predetermined direction of at least one of the gratings of the third region is different from the predetermined direction of the other grating of the third region.

According to an embodiment of the invention, the first wavelength range comprises at least one of about 600 nm to about 680 nm, the second wavelength range comprises at least one of about 500 nm to about 570 nm, and the third wavelength range comprises about 400. From at least one wavelength from nm to about 490 nm.

The description of the embodiments of the present invention is intended to be illustrative and not restrictive. The embodiments disclosed herein may be combined or substituted with each other in an advantageous manner, and other embodiments may be added to an embodiment without further description or description.

In the following description, numerous specific details are set forth However, embodiments of the invention may be practiced without these specific details. In other instances, well-known structures and devices are only schematically shown in the drawings in order to simplify the drawings.

One aspect of the present invention provides a light guide plate. 1 is a top plan view of a light guide plate 100 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a line segment 2-2' in FIG. The light guide plate 100 includes a light incident surface 101 and a light exit surface 102. The light incident surface 101 is configured to receive an incident light, and the light is transmitted through the light guide plate 100 and exits the light guide plate 100 via the light exit surface 102. The light guide plate 100 is made of a material that is transparent to visible light, such as poly MMA methacrylate PMMA.

Referring to FIG. 1 and FIG. 2 simultaneously, the light-emitting surface 102 of the light guide plate 100 includes a first region 110, and the first region 110 includes a plurality of gratings 110a, which cooperate to allow light of the first wavelength range to pass through and block Light of another wavelength range passes. Therefore, when the light enters the light guide plate from the light incident surface 101, the first region 110 can be made to have a color such as red, green or blue. The above "preventing the passage of light of another wavelength range" can be understood as the transmittance of the light of the grating for the light of another wavelength range is significantly lower than the transmittance of the light of the first wavelength range, and the light passing through the grating has a non- White color. For example, the transmittance of the grating to light of the first wavelength range is greater than 60% or higher, and the transmittance of the grating to light of the other wavelength range is less than 30% or less. More specifically, the grating 110a is capable of reflecting light of the other wavelength range described above. In one embodiment, the first wavelength range includes at least one of about 600 nm to about 680 nm, and the blocked other wavelength range includes at least one of about 500 nm to about 570 nm and about 400 nm to At least one wavelength in about 490 nm. In another embodiment, the first wavelength range includes at least one wavelength from about 500 nm to about 570 nm, and the other wavelength range that is blocked comprises at least one wavelength from about 600 nm to about 680 nm and about 400 nm to At least one wavelength in about 490 nm. In still another embodiment, the first wavelength range includes at least one wavelength from about 400 nm to about 490 nm, and the blocked other wavelength range includes at least one wavelength from about 600 nm to about 680 nm and about 500 nm to At least one wavelength in about 570 nm. In one embodiment, the gratings 110a can be made, for example, of a material having a refractive index of from about 1.5 to about 1.65. In other embodiments, the gratings 110a can be diffraction gratings.

The gratings 110a in the first region 110 are spaced apart from each other by a pitch w, in other words, any two gratings 110a are not physically connected or in contact with each other. Each of the gratings 110a of the first region 110 has a plurality of prisms extending toward a predetermined direction. The predetermined direction of the prism of the at least one grating 110a of the first region 110 is different from the predetermined direction of the prism of the other grating of the first region 110, as will be described in detail below.

For example, as shown in FIG. 1, the gratings 110a in the first region 110 include at least a first grating 111 and a second grating 112. FIG. 3A is a top view of the first grating 111, and FIG. 3B is a schematic cross-sectional view of the first grating 111. The first grating 111 has a plurality of prisms 111a, and these prisms 111a extend toward the first direction D1. The ridge lines 111t of each of the prisms 111a are substantially parallel to the first direction D1, and the prisms 111a are regularly arranged and arranged in a first pitch P1. A groove 111b is formed between any two adjacent prisms 111a. In one embodiment, in order for the gratings 110a of the first region to cooperate to pass light of the first wavelength range and prevent light of another wavelength range from passing, the first pitch P1 is from about 0.2 μm to about 22.3. Mm. If the first pitch P1 exceeds the above range, it is difficult for the first region 110 to form a light-transmitting region of three primary colors such as red light, green light, or blue light. On the other hand, the top of the first prism 111a has an angular angle β. The angular angle β can be, for example, from about 80 degrees to about 125 degrees, and the above-described angular angle β is also designed to allow the first region 110 to allow red, green or blue light to pass. In other embodiments, the first grating 111 can have more than two first pitch values and angular angles, as shown in FIG. 3C. The first grating 111 includes a first portion 1111, a second portion 1112, and a third portion 1113. The edge angles β and third of the prisms in the first part 1111 The corners β of the prisms in the portion 1113 are substantially the same angle, and the prisms in the first portion 1111 and the prisms in the third portion 1113 are arranged at substantially the same pitch. The second portion 1112 is located between the first portion 1111 and the third portion 1113. The edge angle α of the prisms in the second portion 1112 is greater than the angular angle β of the first portion 1111 and the third portion 1113. The angle α may be, for example, about 115 degrees to about At 125 degrees, the angular angle β can be, for example, from about 85 degrees to about 95 degrees. In an embodiment, the prisms 111a can be made, for example, of a material having a refractive index of from about 1.5 to about 1.65.

FIG. 4 is a top view of the second grating 112. The second grating 112 has a plurality of prisms 112a extending toward the second direction D2, and the second direction D2 is substantially perpendicular to the first direction D1. In other words, the angle between the second direction D2 and the first direction D1 is θ2 of about 90 degrees. The pitch and angular angle of the prisms 112a of the second grating 112 may be the same as or different from the prisms 111a in the first grating 111. Referring again to FIG. 1, the spacing w between the second grating 112 and the first grating 111 may be, for example, about 1 μm to about 15 μm. The range of the above-mentioned pitch w is obtained through many experiments. If the pitch w is less than about 1 μm, interference occurs between the two gratings 111 and 112, which is disadvantageous for the interaction between the two gratings 111 and 112. If the pitch w is greater than about 15 μm, the spacing between the two gratings 111, 112 is too far, causing all of the visible wavelengths of light to pass through in the spacing region. In other words, if the pitch w is outside the range of about 1 μm to about 15 μm described above, it is difficult for the gratings 110a to act together to produce an effect of allowing light of one wavelength range to pass and preventing light of another wavelength range from passing.

In an embodiment, the first region 110 further includes a third grating 113 and a fourth grating 114. 5 and 6 illustrate the third grating 113, respectively. And a top view of the fourth grating 114. The third grating 113 has a plurality of prisms 113a that extend toward the third direction D3. The fourth grating 114 has a plurality of prisms 114a that extend toward the fourth direction D4. The angle θ3 between the third direction D3 and the first direction D1 is about 25 degrees to about 35 degrees, and the angle θ4 between the fourth direction D4 and the first direction D1 is about 55 degrees to about 65 degrees. The prisms 113a of the third grating 113 are arranged in a manner of a third pitch P3. The prisms 114a of the fourth grating 114 are arranged in a fourth pitch P4. In an example, the third pitch P3 is substantially equal to the first pitch P1 of the first grating 111, but the first pitch P1 is greater than the second pitch P2 of the second grating 112. The fourth pitch P4 is substantially the second pitch P2. In other examples, the first pitch P1, the second pitch P2, the third pitch P3, and the fourth pitch P4 are substantially equal. The first pitch P1, the second pitch P2, the third pitch P3, and the fourth pitch P4 are between about 0.2 μm and about 22.3 μm.

In another embodiment, the first region 110 further includes a fifth grating 115 and a sixth grating 116. 7 and 8 are schematic top views of the fifth grating 115 and the sixth grating 116, respectively. The fifth grating 115 has a plurality of prisms 115a that extend toward the fifth direction D5. The sixth grating 116 has a plurality of prisms 116a extending toward the sixth direction D6. The angle θ5 between the fifth direction D5 and the first direction D1 is about 115 degrees to about 125 degrees. The angle θ6 between the sixth direction D6 and the first direction D1 is about 145 degrees to about 155 degrees. The prisms 115a of the fifth grating 115 are arranged in a fifth pitch P5. The prisms 116a of the sixth grating 116 are arranged at a sixth pitch P6. The fifth pitch P5 and the sixth pitch P6 are between about 0.2 μm and about 22.3 μm. In an embodiment, the first pitch P1, the second pitch P2, the third pitch P3, the fourth pitch P4, the fifth pitch P5, and the sixth pitch P6 are substantially equal. In other embodiments, the first, second, third, fourth, fifth, and sixth gratings 111, 112, 113, 114, 115, and 116 may also be diffraction gratings.

In an embodiment, as shown in FIG. 1, the first grating 111, the second grating 112, and the third grating 113 are substantially disposed on the same column, and the fourth grating 114, the fifth grating 115, and the sixth grating 116 are disposed. It is essentially placed on another column. The right edge of the fourth grating 114 and the left edge of the second grating 112 are disposed substantially on the line L1, in other words, the right edge of the fourth grating 114 is substantially aligned with the right edge of the second grating 112. The right edge edge of the fifth grating 115 and the left edge of the third grating 113 are substantially disposed on another straight line L2. The above arrangement is advantageous in that these gratings can cooperate to produce an effect of allowing light of one wavelength range to pass and preventing light of another wavelength range from passing. In another embodiment, the area of each of the gratings 111, 112, 113, 114, 115, 116 is substantially equal. The area of each of the windings 111, 112, 113, 114, 115, 116 may be, for example, about 4 μm ² to about 4000 μm ² .

In still another embodiment, as shown in FIG. 1 , the light-emitting surface 102 of the light guide plate 100 further includes a second region 120 and a third region 130 . The second region 120 has a plurality of gratings 120a spaced apart from each other by a pitch. Each of the gratings 120a of the second region 120 has a plurality of prisms extending toward a predetermined direction. The predetermined direction of the prism of at least one of the gratings 120a in the second region 120 is different from the predetermined direction of the other grating 120a of the second region 120. The gratings 120a of the second region 120 cooperate to pass light of a second wavelength range and block the passage of light of another wavelength range. The third region 130 has a plurality of gratings 130a spaced apart from each other by a pitch. Each grating of the third region 130 130a has a plurality of prisms extending toward a predetermined direction. The predetermined direction of the prism of at least one of the gratings 130a in the third region 130 is different from the predetermined direction of the other grating 130a of the third region 130. The gratings 130a of the third region 130 cooperate to pass light of a third wavelength range and prevent light of another wavelength range from passing. In this embodiment, the first region 110 allows light to pass through (or pass through) the first wavelength range comprises at least one of about 600 nm to about 680 nm, and the wavelength range of light that is blocked from passing includes about 500 nm to At least one wavelength in about 570 nm and at least one wavelength in about 400 nm to about 490 nm. That is, the first region 110 allows red light to pass through, but the green light and the blue light do not substantially penetrate the first region 110, or the transmittances of the green light and the blue light are low relative to the red light. The second region 120 allows the light to pass through (or pass through) the second wavelength range comprising at least one of about 500 nm to about 570 nm, and the wavelength range of light that is blocked from passing includes at least about 600 nm to about 680 nm. A wavelength and at least one of about 400 nm to about 490 nm. That is, the second region 120 allows green light to pass through, but the red light and the blue light do not substantially penetrate the second region 120, or the transmittances of the red light and the blue light are low relative to the green light. The third region 130 allows the second wavelength range through which light is transmitted (or passed) to include at least one of about 400 nm to about 490 nm, and the wavelength range of light that is blocked from passing includes at least about 600 nm to about 680 nm. One wavelength and at least one wavelength from about 500 nm to about 570 nm. That is, the third region 130 allows blue light to pass through, but the red light and the green light do not substantially penetrate the third region 130, or the transmittances of the red light and the green light are low relative to the blue light. By adjusting the angular angle of the prism of the grating in the first region 110, the second region 120, and the third region 130, the pitch of the prism, and the arrangement of the grating, the first region 110, the second region 120, and the third region can be made. 130 Red, green, and blue light are allowed to pass through, respectively, and red, green, and blue regions are respectively present.

FIG. 9 is a cross-sectional view showing an electrophoretic display device 500 in a switchable color mode and a black-and-white mode according to an embodiment of the present invention. The electrophoretic display device 500 includes the light guide plate 100, the electrophoretic display panel 200, and the light source 300 according to any of the embodiments or examples described above.

The light source 300 is used to emit light 301, and the light 301 enters the inside of the light guide plate via the light incident surface 101 of the light guide plate. In one embodiment, the light source 300 includes a red light emitting diode, a green light emitting diode, and a blue light emitting diode. The red light emitting diode emits light having a principal wavelength of about 600 nm to about 700 nm, and the green light emitting diode emits light having a dominant wavelength of about 500 nm to about 600 nm, and the blue light emitting diode emits a main light. Light having a wavelength of from about 380 nm to about 480 nm. In another embodiment, the light source 300 is a white laser or a diode.

The light guide plate may be the light guide plate 100 of any of the embodiments or embodiments described above. In an embodiment, the light-emitting surface 102 of the light guide plate includes a first region 110, a second region 120, and a third region 130. The first region 110 has a plurality of gratings spaced apart from each other by a spacing, and the gratings of the first region 110 cooperate to pass light of the first wavelength range and prevent light of another wavelength range from passing. The second region 120 has a plurality of gratings spaced apart from each other by a spacing, and the gratings of the second region 120 cooperate to pass light of the second wavelength range and prevent light of another wavelength range from passing. The third region 130 has a plurality of gratings spaced apart from each other by a spacing, and the gratings in the third region 130 cooperate to pass light of a third wavelength range and prevent light of another wavelength range from passing. For example, the first region 110 is substantially only allowed to have a wavelength of about 600 nm. The red light of about 680 nm penetrates through, and the transmittance of light of other wavelengths is relatively low. The second region 120 generally allows only green light having a wavelength of about 500 nm to about 570 nm to pass through, and the transmittance of light of other wavelengths is relatively low. The third region 130 substantially only allows blue light having a wavelength of about 400 nm to about 490 nm to pass through, and the transmittance of light of other wavelengths is relatively low.

The electrophoretic display panel 200 has a display surface including at least a first sub-pixel 210, a second sub-pixel 220, and a third sub-pixel 230. The first, second, and third sub-pixels 210, 220, and 230 correspond to the first region 110, the second region 120, and the third region 130, respectively. The electrophoretic display panel 200 can be, for example, a microcup electrophoretic display panel or a microcapsule electrophoretic display panel; however, the electrophoretic display panel 200 does not include a dye-type or pigment-type color filter of the prior art. Therefore, the electrophoretic display panel 200 exhibits only black, white, and simple gray scales. When the first region 110, the second region 120, and the third region 130 emit light having a specific color projected onto the first, second, and third sub-pixels 210, 220, 230, the first, second, and third The white pigment particles in the sub-pixels 210, 220, and 230 can reflect the incident light, and the sub-pixels that originally have no color exhibit color. Therefore, according to the electrophoretic display device disclosed in the embodiment of the present invention, a color image can be presented without using a color filter. More importantly, when the light source 300 is turned on, the light emitted by the light source 300 is designed through the special optical design of the light guide plate 100, and the electrophoretic display device 500 is brought into the color display mode. On the contrary, when the light source 300 is turned off, the electrophoretic display device 500 assumes the original black and white display mode. Therefore, the electrophoretic display device 500 is a switchable color mode and a black and white mode.

According to the above embodiments of the present invention, the electrophoretic display device does not need to be used. Color filters are capable of rendering color images. Further, the electrophoretic display device can be switched from the color display mode to the monochrome display mode or the monochrome display mode to the color display mode in the use state.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

100‧‧‧Light guide plate

101‧‧‧Into the glossy surface

102‧‧‧Glossy surface

110‧‧‧First area

110a‧‧·raster

111‧‧‧First grating

111a‧‧‧ prism

111b‧‧‧ Groove

111t‧‧‧ ridgeline

1111‧‧‧Part 1

1112‧‧‧Part II

1113‧‧‧Part III

112‧‧‧second grating

112a‧‧‧ prism

113‧‧‧ Third grating

113a‧‧‧ prism

114‧‧‧fourth grating

114a‧‧‧ prism

115‧‧‧ Fifth grating

115a‧‧‧ prism

116‧‧‧ sixth grating

116a‧‧‧ prism

120‧‧‧Second area

120a‧‧·raster

130‧‧‧ Third Area

130a‧‧·raster

200‧‧‧electrophoretic display panel

210‧‧‧The first sub-pixel

220‧‧‧Second sub-pixel

230‧‧‧ Third sub-pixel

300‧‧‧Light source

301‧‧‧Light

500‧‧‧electrophoretic display device

2-2’‧‧‧ segments

L1, L2‧‧‧ straight line

D1‧‧‧ first direction

D2‧‧‧ second direction

D3‧‧‧ third direction

D4‧‧‧ fourth direction

D5‧‧‧ fifth direction

D6‧‧‧ sixth direction

P1‧‧‧ first pitch

P2‧‧‧Second pitch

P3‧‧‧ third pitch

P4‧‧‧Fourth pitch

P5‧‧‧ fifth pitch

P6‧‧‧ sixth pitch

W‧‧‧ spacing

、, β‧‧‧ angular

Θ2, θ3, θ4‧‧‧ angle

Θ5, θ6‧‧‧ angle

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood.

FIG. 1 is a schematic top view of a light guide plate according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view showing the extended line segment 2-2' in Fig. 1.

FIG. 3A is a schematic top view of the first grating according to an embodiment of the present invention.

FIG. 3B is a cross-sectional view showing the first grating according to an embodiment of the present invention.

FIG. 3C is a cross-sectional view showing the first grating of another embodiment of the present invention.

Figure 4 is a top plan view of the second grating.

FIG. 5 is a top plan view showing a third grating according to an embodiment of the present invention.

6 is a top view of a fourth grating according to an embodiment of the present invention. Figure.

FIG. 7 is a top plan view showing a fifth grating according to an embodiment of the present invention.

FIG. 8 is a schematic top view of a sixth grating according to an embodiment of the present invention.

FIG. 9 is a cross-sectional view showing an electrophoretic display device capable of switching between a color mode and a black and white mode according to an embodiment of the present invention.

101‧‧‧Into the glossy surface

102‧‧‧Glossy surface

110‧‧‧First area

120‧‧‧Second area

130‧‧‧ Third Area

200‧‧‧electrophoretic display panel

210‧‧‧The first sub-pixel

220‧‧‧Second sub-pixel

230‧‧‧ Third sub-pixel

300‧‧‧Light source

301‧‧‧Light

500‧‧‧electrophoretic display device

Claims (20)

A light guide plate comprising: a light incident surface for receiving an incident light; and a light emitting surface comprising at least a first region having a plurality of gratings spaced apart from each other by a spacing, each of the first regions The gratings have a plurality of prisms extending in a predetermined direction, and a predetermined direction of at least one of the gratings of the first region is different from a predetermined direction of another grating of the first region, wherein the gratings of the first region cooperate To allow light of a first wavelength range to pass, and to block the passage of light in another wavelength range. The light guide plate of claim 1, wherein the gratings comprise a first grating and a second grating, the first grating has a plurality of prisms extending in a first direction, and the second grating has a plurality of prisms to a second The direction extends, the first direction being substantially perpendicular to the second predetermined direction. The light guide plate of claim 2, wherein the gratings further comprise a third grating and a fourth grating, the third grating having a plurality of prisms extending in a third direction, the fourth grating having a plurality of prisms The fourth direction extends, and the angle between the third direction and the first direction is about 25 degrees to about 35 degrees, and the angle between the fourth direction and the first direction is about 55 degrees to about 65 degrees. The light guide plate of claim 3, wherein the gratings further comprise a fifth grating and a sixth grating, the fifth grating having a plurality of prisms extending in a fifth direction, the sixth grating having a plurality of prisms Six-direction extension The angle between the fifth direction and the first direction is about 115 degrees to about 125 degrees, and the angle between the sixth direction and the first direction is about 145 degrees to about 155 degrees. The light guide plate of claim 4, wherein the first, second, and third gratings are substantially disposed on the same column, and the fourth, fifth, and sixth gratings are substantially disposed on another column. The light guide plate of claim 4, wherein one edge of the fourth grating and one edge of the second grating are substantially disposed on a straight line, and one edge of the fifth grating and one edge of the third grating are substantially Configured on another line. The light guide plate of claim 4, wherein the prisms of the first grating are arranged at a first pitch, and the prisms of the second grating are arranged at a second pitch, the prisms of the third grating Arranged at a third pitch, and wherein the first pitch is substantially equal to the third pitch, the first pitch being greater than the second pitch. The light guide plate of claim 1, wherein each of the gratings has an area substantially equal. The light guide plate of claim 1, wherein the pitch is from about 1 μm to about 15 μm. The light guide plate of claim 1, wherein the prisms are arranged at a pitch of from about 0.2 μm to about 22.3 μm. The light guide plate of claim 1, wherein the first wavelength range comprises at least one of about 600 nm to about 680 nm, and the other wavelength range comprises at least one of about 500 nm to about 570 nm and about At least one wavelength from 400 nm to about 490 nm. The light guide plate of claim 1, wherein the first wavelength range comprises at least one wavelength from about 500 nm to about 570 nm, and the other wavelength range comprises at least one wavelength from about 600 nm to about 680 nm and about 400 From at least one wavelength from nm to about 490 nm. The light guide plate of claim 1, wherein the first wavelength range comprises at least one wavelength from about 400 nm to about 490 nm, and the other wavelength range comprises at least one wavelength from about 600 nm to about 680 nm and about 500 From at least one wavelength from nm to about 570 nm. The light guide plate of claim 1, wherein the light exiting surface further comprises a second region having a plurality of gratings spaced apart from each other by a distance, each of the gratings of the second region having a plurality of prisms extending in a predetermined direction, The predetermined direction of the at least one of the gratings of the second region is different from the predetermined direction of the other grating of the second region, wherein the gratings of the second region cooperate to pass light of a second wavelength range and block Light of another wavelength range passes. . The light guide plate of claim 14, wherein the light exiting surface further comprises a third region having a plurality of gratings spaced apart from each other by a distance, wherein each of the gratings of the third region has a plurality of prisms extending in a predetermined direction, The predetermined direction of at least one of the gratings of the third region is different from the predetermined direction of the other grating of the third region, wherein the gratings of the third region cooperate to pass light of a third wavelength range and block The passage of light of another wavelength range. An electrophoretic display device capable of switching between a color mode and a black and white mode, comprising: an electrophoretic display panel comprising a first sub-pixel, a second sub-pixel and a third sub-pixel; and a light source for emitting a light And a light guide plate comprising: a light incident surface for receiving the light; and a light exit surface comprising a first region, a second region and a third region, wherein the first region has a plurality of gratings spaced apart from each other a grating, the gratings of the first region cooperate to pass light of a first wavelength range, and block the passage of light of another wavelength range, the second region having a plurality of gratings spaced apart from each other, the second region The gratings cooperate to pass light of a second wavelength range and prevent light of another wavelength range from passing, and the third area has a plurality of gratings spaced apart from each other by a spacing The gratings of the three regions cooperate to pass light of a third wavelength range and prevent light of another wavelength range from passing through; wherein when the light source is turned on, the first, second and third regions respectively Lights of the first, second, and third wavelength ranges are projected toward the first, second, and third sub-pixels, such that the electrophoretic display device is in a color mode, and when the light source is turned off, the electrophoretic display device is Black and white mode. The electrophoretic display device of claim 16, wherein each of the gratings of the first region has a plurality of prisms extending in a predetermined direction, and a predetermined direction of at least one of the gratings of the first region is different from the first region The predetermined direction of the other grating. The electrophoretic display device of claim 16, wherein each of the gratings of the second region has a plurality of prisms extending in a predetermined direction, and a predetermined direction of at least one of the gratings of the second region is different from the second region The predetermined direction of the other grating. The electrophoretic display device of claim 16, wherein each of the gratings of the third region has a plurality of prisms extending in a predetermined direction, and a predetermined direction of at least one of the gratings of the third region is different from the third region The predetermined direction of the other grating. The electrophoretic display device of claim 16, wherein the first wavelength range comprises at least one of about 600 nm to about 680 nm, and the second wavelength range comprises at least one of about 500 nm to about 570 nm, The third wavelength range includes at least one of about 400 nm to about 490 nm.