CN211426843U - Image capturing device - Google Patents

Abstract

An image capturing device comprises a light guide plate, a first light transmitting layer, a second light transmitting layer, a third light transmitting layer, an illuminating element and an image capturing element. The light guide plate has a first surface and a second surface opposite to the first surface. The first light-transmitting layer is arranged on one side of the first surface. The second light-transmitting layer is disposed on one side of the second surface, wherein the second light-transmitting layer overlaps with the light-transmitting region of the light guide plate and does not overlap with the light-transmitting region of the light guide plate. The third light-transmitting layer is arranged on one side of the second surface and is overlapped with the light-transmitting area and the light-penetrating area. The refractive index of the third light-transmitting layer and the refractive index of the light guide plate are higher than the refractive index of the first light-transmitting layer and the refractive index of the second light-transmitting layer.

Description

Image capturing device

Technical Field

The present invention relates to an electronic device, and more particularly to an image capturing device.

Background

The biometric identification includes face, voice, iris, retina, vein, palm print, fingerprint identification, etc. Depending on the sensing method, biometric identification devices can be classified into optical, capacitive, ultrasonic, and thermal sensing. Generally, the optical biometric device includes an illumination device, a light guide device and an image capturing device. The light beam emitted by the lighting element irradiates the object to be measured pressed on the light guide element. The image capturing element receives the light beam reflected by the object to be measured so as to identify the biological characteristics. In the process of image capture by the image capturing device, the light beam reflected by the object to be detected is easily transmitted to the sensor in a scattered manner, which causes poor image capturing quality and affects the identification result. Although some techniques have been proposed to improve the image quality, the improvement of the prior art still has difficulty in effectively dealing with the problem of crosstalk.

SUMMERY OF THE UTILITY MODEL

The utility model provides a get for instance device, it can have good discernment ability.

The utility model discloses an get for instance device of an embodiment includes light guide plate, first euphotic layer, second euphotic layer, third euphotic layer, lighting element and gets for instance the component. The light guide plate has a first surface, a second surface opposite to the first surface, and a plurality of third surfaces each connecting the first surface to the second surface. The first light-transmitting layer is arranged on one side of the first surface. The second light-transmitting layer is disposed on one side of the second surface, wherein the second light-transmitting layer overlaps with the light-transmitting region of the light guide plate in the normal direction of the light guide plate, and the second light-transmitting layer does not overlap with the light-transmitting region of the light guide plate in the normal direction. The third light-transmitting layer is arranged on one side of the second surface and is overlapped with the light transmission region and the light penetration region in the normal direction. The refractive index of the third light-transmitting layer is higher than the refractive index of the first light-transmitting layer and the refractive index of the second light-transmitting layer, and the refractive index of the light guide plate is higher than the refractive index of the first light-transmitting layer and the refractive index of the second light-transmitting layer.

Based on the above, two light-transmitting layers (e.g., the first light-transmitting layer and the second light-transmitting layer) with low reflectivity are disposed on two sides of the light guide plate, and most of the light beams can be transmitted through the light guide plate by total reflection. In addition, the design that the second light-transmitting layer is not overlapped with the light-transmitting area and the third light-transmitting layer is overlapped with the light-transmitting area allows the light beam transmitted in the light guide plate to be transmitted to the surface of the third light-transmitting layer pressed by the object to be measured, and the light beam reflected by the object to be measured returns to the light guide plate after passing through the third light-transmitting layer and then is transmitted to the image capturing element through total reflection. Therefore, the messy light beams received by the image capturing element can be reduced, and the image capturing device of the embodiment has good identification capability.

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

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

Fig. 1 is a schematic top view of an image capturing device according to a first embodiment of the present invention.

Fig. 2 is a schematic partial cross-sectional view of an image capturing device according to a first embodiment of the present invention.

Fig. 3 is a schematic partial cross-sectional view of an image capturing device according to a second embodiment of the present invention.

Fig. 4 is a schematic partial cross-sectional view of an image capturing device according to a third embodiment of the present invention.

Fig. 5 is a schematic partial cross-sectional view of an image capturing device according to a fourth embodiment of the present invention.

Fig. 6 is a schematic partial cross-sectional view of an image capturing device according to a fifth embodiment of the present invention.

Fig. 7 is a schematic top view of an image capturing device according to a sixth embodiment of the present invention.

Fig. 8 is a schematic partial cross-sectional view of an image capturing device according to a sixth embodiment of the present invention.

Fig. 9 is a schematic partial cross-sectional view of an image capturing device according to a seventh embodiment of the present invention.

Fig. 10 is a schematic top view of an image capturing device according to an eighth embodiment of the present invention.

Fig. 11 is a schematic partial cross-sectional view of an image capturing device according to a ninth embodiment of the present invention.

Fig. 12 is a partial enlarged view of the light directing element and the illumination element of fig. 11.

Fig. 13 is a schematic partial cross-sectional view of an image capturing device according to a tenth embodiment of the present invention.

Fig. 14 is a partial cross-sectional view of a light guide element and a lighting element according to an embodiment of the invention.

Fig. 15 is a schematic top view of an image capturing device according to an eleventh embodiment of the present invention.

Fig. 16 is a schematic top view of an image capturing device according to a twelfth embodiment of the present invention.

Fig. 17 is a schematic top view of an image capturing device according to a thirteenth embodiment of the present invention.

Wherein:

1. 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L image capturing device

10. 10K light guide plates 11, 11B, 11E first light-transmitting layer

12. 12E a second light-transmitting layer 13, 13D a third light-transmitting layer

14 lighting element 15 image-taking element

16 carrier plate 17 fourth light-transmitting layer

18. 18A, 18B, a light guide element 19, a first adhesive layer

20 second adhesive layer 110 transparent pattern

180. 180A main body 182 microstructure

184 optical layer AG air gap

B. B1, B2, B1 ', B2' light beam D concave

G gaps n10, n11, n12, n13 refractive index

NL normal NT groove

O opening OBJ waiting object

P1, P1A first part P2 second part

R1 light transmission region R2 light penetration region

R3 display region S1 first surface

S2 second surface S3 third surface

S13, S13D surface SS1 first edge

SS2 second side ST slit

T182, TP1, TP2 thickness WG width

X, Y direction Z normal direction

Alpha and beta, included angle theta and incident angle.

Detailed Description

Directional phrases used in connection with embodiments, such as: the upper, lower, front, rear, left, right, etc. are only referred to the direction of the drawing. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting. In addition, when a layer/element (e.g., a first layer/element) is described as being disposed on another layer/element (e.g., a second layer/element), the first layer/element can be disposed directly on the second layer/element with no additional layers/elements disposed therebetween; alternatively, the first layer/element may be disposed on the second layer/element with additional layers/elements disposed therebetween.

In the drawings, the figures depict typical features of methods, structures, and/or materials used in certain exemplary embodiments. These drawings, however, should not be construed as defining or limiting the scope or nature of what is covered by these exemplary embodiments. For example, the relative dimensions, thicknesses, and locations of various layers, regions, and/or structures may be reduced or exaggerated for clarity.

In the embodiments, the same or similar elements will be denoted by the same or similar reference numerals, and the detailed description thereof will be omitted. Furthermore, the features of the different exemplary embodiments may be combined without conflict and simple equivalent variations and modifications made in accordance with the present specification or claims may still fall within the scope of the present invention. In addition, the terms "first" and "second" used in the description and the claims are only used for naming the individual components or distinguishing different embodiments or ranges, and are not used for limiting the upper limit or the lower limit of the number of the components, nor the manufacturing order or the arrangement order of the components.

In an embodiment of the present invention, each of the image capturing devices is adapted to capture a biological characteristic of the object. The object to be measured may be a finger, a palm, a wrist or an eyeball of the user, and the corresponding biological characteristic may be a fingerprint, a palm print, a vein, a pupil or an iris, but the present invention is not limited thereto. In the following embodiments, the present invention will be further described by taking a finger as an example of the analyte.

Fig. 1 is a schematic top view of an image capturing device 1 according to a first embodiment of the present invention, and fig. 2 is a schematic partial cross-sectional view of the image capturing device 1 according to the first embodiment of the present invention.

Referring to fig. 1 and fig. 2, the image capturing device 1 of the first embodiment includes a light guide plate 10, a first transparent layer 11, a second transparent layer 12, a third transparent layer 13, an illuminating element 14, and an image capturing element 15.

The light guide plate 10 is adapted to transmit (transmit) a light beam, and the light beam may be transmitted (transmitted) therein in a Total Internal Reflection (TIR) manner. The light guide plate 10 may be transparent to reduce loss of the light beam transmitted therein, but the light transmittance of the light guide plate 10 (the percentage of the light beam passing through the light guide plate 10) is not limited to 100%. For example, the light guide plate 10 may be a glass light guide plate, a plastic light guide plate, or a combination thereof, but the present invention is not limited thereto.

The light guide plate 10 has a first surface S1, a second surface S2, and a plurality of third surfaces S3, wherein the second surface S2 is opposite to the first surface S1, and each of the plurality of third surfaces S3 connects the first surface S1 to the second surface S2. As shown in fig. 2, the first surface S1 may be a bottom surface of the light guide plate 10, and the first surface S1 is far away from the object OBJ to be identified. The second surface S2 may be the top surface of the light guide plate 10, and the second surface S2 faces the object OBJ. The third surface S3 may be a side surface of the light guide plate 10, and the third surface S3 is disposed between the first surface S1 and the second surface S2.

The light guide plate 10 has a light transmitting region R1 and a light transmitting region R2. The light transmitting region R1 is a region where the light beam is transmitted by total reflection in the light guide plate 10. The light penetration region R2 is a region where the light beam is transmitted from the light guide plate 10 and transmitted to the object OBJ. That is, the light transmission region R2 corresponds to a region of the image capturing device 1 pressed by the object OBJ to perform biometric authentication. In one embodiment, the light transmitting region R1 surrounds the light transmitting region R2, but the present invention is not limited to the arrangement relationship between the light transmitting region R1 and the light transmitting region R2.

The first light-transmitting layer 11 is disposed on one side of the first surface S1. In an embodiment, the first transparent layer 11 may be, for example, a continuous transparent layer, but the invention is not limited thereto. In addition, the first light-transmitting layer 11 overlaps the light transmission region R1 and the light-transmitting region R2 in the normal direction Z of the light guide plate 10, but the present invention is not limited thereto.

The first light-transmitting layer 11 may be transparent, but the light transmittance of the first light-transmitting layer 11 is not limited to 100%. For example, the first transparent layer 11 may be made of a fluorine-containing material or a silicon-containing material, but the invention is not limited thereto. In addition, the first light-transmitting layer 11 may include a multilayer structure. In detail, the first light-transmitting layer 11 may be formed by stacking a plurality of optical film layers.

The second light-transmitting layer 12 is disposed on one side of the second surface S2. The second light-transmitting layer 12 overlaps with the light-transmitting region R1 in the normal direction Z, and the second light-transmitting layer 12 does not overlap with the light-transmitting region R2 in the normal direction Z. That is, the light transmitting region R1 is at least partially covered by the second light-transmitting layer 12, and the light transmitting region R2 is at least partially uncovered by the second light-transmitting layer 12. For example, the second transparent layer 12 may have an opening O, wherein the opening O overlaps the light transmissive region R2 in the normal direction Z, but the invention is not limited thereto. The shape of the opening O (or the shape of the second light-transmitting layer 12) may be circular,

Quadrilateral, or other suitable shape.

The second light-transmitting layer 12 may be transparent, but the light transmittance of the second light-transmitting layer 12 is not limited to 100%. For example, the second transparent layer 12 may be made of a fluorine-containing material or a silicon-containing material, but the invention is not limited thereto. In addition, the material of the first light-transmitting layer 11 may be the same as or different from the material of the second light-transmitting layer 12.

The third transparent layer 13 is also disposed on one side of the second surface S2 and overlaps the light transmitting region R1 and the light transmitting region R2 in the normal direction Z. For example, the third light-transmitting layer 13 may be disposed on the second light-transmitting layer 12 and the light guide plate 10 not covered by the second light-transmitting layer 12, such that the second light-transmitting layer 12 is located between the third light-transmitting layer 13 and the light guide plate 10, and a portion of the third light-transmitting layer 13 is located in the opening O, but the present invention is not limited to the disposition relationship between the second light-transmitting layer 12 and the third light-transmitting layer 13.

The third light-transmitting layer 13 may be transparent, but the light transmittance of the third light-transmitting layer 13 is not limited to 100%. For example, the third transparent layer 13 may be made of acrylic, epoxy resin or Optically Clear Adhesive (OCA), but the present invention is not limited thereto.

The refractive index n13 of the third light-transmitting layer 13 is higher than the refractive index n11 of the first light-transmitting layer 11 and the refractive index n12 of the second light-transmitting layer 12, and the refractive index n10 of the light guide plate 10 is higher than the refractive index n11 of the first light-transmitting layer 11 and the refractive index n12 of the second light-transmitting layer 12. For example, the refractive index n11 of the first light-transmitting layer 11 (which is an average refractive index of the first light-transmitting layer 11 if the first light-transmitting layer 11 is formed by stacking a plurality of optical film layers) is greater than 1 and less than or equal to 1.45 (i.e., 1< n11 ≦ 1.45), the refractive index n11 of the second light-transmitting layer 12 is greater than 1 and less than or equal to 1.45 (i.e., 1< n12 ≦ 1.45), the refractive index n13 of the third light-transmitting layer 13 is greater than or equal to 1.5 (i.e., 1.5 ≦ n13), and the refractive index n10 of the light guide plate 10 is greater than or equal to 1.5 (i.e., 1.5 ≦ n 10.

In one embodiment, the refractive index difference (e.g., n10-n11) between the light guide plate 10 and the first light-transmitting layer 11 may be greater than or equal to 0.05, and the refractive index difference (e.g., n10-n12) between the light guide plate 10 and the second light-transmitting layer 12 may be greater than or equal to 0.05, thereby facilitating the formation of total reflection. In a preferred embodiment, the refractive index difference between the light guide plate 10 and the first light-transmitting layer 11 is 0.05, and the refractive index difference between the light guide plate 10 and the second light-transmitting layer 12 is 0.05.

The refractive index n13 of the third light-transmitting layer 13 may be higher than or equal to the refractive index n10 of the light guide plate 10. For example, the refractive index n13 of the third light-transmitting layer 13 may be slightly larger than the refractive index n10 of the light guide plate 10. In the present embodiment, the refractive index of the third light-transmitting layer 13 approaches the refractive index n10 of the light guide plate 10. In this way, the interface reflection at the interface between the light guide plate 10 and the third light transmitting layer 13 and the visibility of the opening O can be reduced, the light beam transmitted from the light transmitting region R1 to the light transmitting region R2 can be transmitted out of the light guide plate 10 to the object OBJ, and the light beam reflected by the object OBJ can enter the light guide plate 10 and be transmitted to the image capturing device 15 through total reflection. In an embodiment, a refractive index difference (e.g., n13-n10) between the light guide plate 10 and the third light-transmitting layer 13 may be less than 0.1.

The lighting element 14 is located below the first surface S1 or beside one of the plurality of third surfaces S3. In an embodiment, the lighting element 14 is located below the first surface S1 and beside the first transparent layer 11, but the invention is not limited thereto. In an embodiment, the first surface S1 may have a groove (not shown) at the light entrance side, and the lighting element 14 may be disposed in the groove. With this configuration, there is a height difference between the portion of the first surface S1 overlapping the lighting element 14 and the portion of the first surface S1 not overlapping the lighting element 14, and the height difference may be about the thickness of the lighting element 14, but the present invention is not limited thereto.

The illumination element 14 is adapted to emit light beams (e.g., light beam B1 and light beam B2) for biometric identification. For example, the lighting elements 14 may be visible lighting elements or invisible lighting elements. The invisible illumination element may be an infrared illumination element, but the present invention is not limited thereto. The lighting element 14 may include one or more light emitting elements, such as one or more light emitting diodes, and the light emitting elements may be disposed along a direction X perpendicular to the normal direction Z, but the invention is not limited thereto.

The image capturing element 15 is located below the first surface S1. For example, the image capturing element 15 is located beside the first light transmitting layer 11, and the illuminating element 14 and the image capturing element 15 are located on opposite sides of the light guide plate 10, but the present invention is not limited thereto. The image capturing element 15 may be adhered to the light guide plate 10 by an adhesive (not shown), but the present invention is not limited thereto. The adhesive may be an optically clear adhesive or an Optically Clear Resin (OCR), but the invention is not limited thereto. In one embodiment, the first surface S1 may have a groove (not shown) at the light outlet side, and the image capturing element 15 may be disposed in the groove. In this configuration, a height difference exists between the portion of the first surface S1 overlapping the image capturing element 15 and the portion of the first surface S1 not overlapping the image capturing element 15, and the height difference may be about the thickness of the image capturing element 15, but the present invention is not limited thereto.

The image capturing device 15 is adapted to receive the light beams (such as the light beam B1 'and the light beam B2') reflected by the object OBJ and transmitted to the image capturing device 15. For example, the image capturing device 15 may include a Charge Coupled Device (CCD), a complementary metal-oxide semiconductor (CMOS) device, or other suitable image sensing devices.

By disposing two light-transmissive layers (e.g., the first light-transmissive layer 11 and the second light-transmissive layer 12) having low reflectivity with respect to the light guide plate 10 on two sides of the light guide plate 10, most of the light beams can be transmitted through the light guide plate 10 by total reflection. In addition, by the design that the second light-transmitting layer 12 does not overlap the light-transmitting region R2 and the third light-transmitting layer 13 overlaps the light-transmitting region R2, the light beam transmitted in the light guide plate 10 can be transmitted to the surface S13 of the third light-transmitting layer 13 pressed by the object OBJ, and the light beam reflected by the object OBJ can return to the light guide plate 10 after passing through the third light-transmitting layer 13 and then be transmitted to the image pickup element 15 through total reflection. Therefore, the stray light beams received by the image capturing element 15 can be reduced, and the image capturing device 1 has good identification capability.

In particular, as shown in fig. 2, light beams (e.g., light beam B1 and light beam B2) emitted from the lighting element 14 enter the light guide plate 10 from the first surface S1. When the incident angle θ of the light beam transmitted to the interface between the light guide plate 10 and the second light transmitting layer 12 meets the condition of total reflection, the light beam can be transmitted in the light guide plate 10 by total reflection toward the image capturing element 15. In one embodiment, θ is 45 ≦ 80.

When the light beam is transmitted from the light transmitting region R1 to the light transmitting region R2, since the second light-transmitting layer 12 having a low reflectance with respect to the light guide plate 10 is not disposed on the second surface S2 in the light transmitting region R2 and the third light-transmitting layer 13 having a similar reflectance with respect to the light guide plate 10 is disposed on the second surface S2 in the light transmitting region R2, at least part of the light beam is transmitted from the light guide plate 10 and transmitted to the surface S13 of the third light-transmitting layer 13 pressed by the object OBJ. The light beam transmitted to the surface S13 of the third light-transmitting layer 13 is reflected by the object OBJ. The reflected light beam (light beam with biological information) passes through the opening O and enters the light guide plate 10, and then is transmitted to the image pickup element 15 through total reflection.

The amount of the light beam transmitted from the light guide plate 10 to the object OBJ is related to the size of the opening O, and the amount of the light beam reflected by the object OBJ and entering the light guide plate 10 is also related to the size of the opening O. In an embodiment, the area of the light penetration region R2 may be defined by the area of the opening O, and the area of the light penetration region R2 may be about the area pressed by the object OBJ, but the invention is not limited thereto.

The image capturing device 1 may further include other components or layers according to different requirements. For example, the image capturing device 1 may further include a carrier 16, wherein the first transparent layer 11 is located between the light guide plate 10 and the carrier 16. The carrier 16 may be a cover plate, a back plate or a display panel, but the present invention is not limited thereto. In one embodiment, the carrier 16 is located outside the transmission path of the light beam emitted from the illumination element 14 and transmitted to the image capturing element 15. Thus, carrier plate 16 may be transparent or opaque.

When the carrier 16 is a display panel, the display panel may be a liquid crystal display panel, a quantum dot display panel, a display panel with a touch electrode, or an organic light emitting display panel, but the present invention is not limited thereto. The display panel has a display region R3 (shown in fig. 1) for displaying an image. The light guide plate 10, the first light-transmitting layer 11, the second light-transmitting layer 12, and the third light-transmitting layer 13 overlap the display region R3 in the normal direction Z. Since the light guide plate 10, the first light-transmitting layer 11, the second light-transmitting layer 12 and the third light-transmitting layer 13 are transparent, the influence of the above layers on the image or the visual effect of the image capturing device 1 can be reduced.

In an embodiment, the carrier 16 may overlap the lighting element 14 in the normal direction Z. The top surface of the carrier plate 16 (the surface facing the light guide plate 10) may have a groove (not shown), and the lighting elements 14 may be disposed in the groove. The subsequent embodiments may be modified as described above, and the duplicated contents will be omitted below.

In an embodiment, the image capturing device 1 may further include a controller (not shown) for controlling the illumination element 14 and the image capturing element 15. The controller and the lighting element 14 can be electrically connected in a wireless or wired manner. For example, the controller and the lighting element 14 may be electrically connected through a Flexible Printed Circuit Board (FPCB), and the FPCB and the controller may be connected through a fastener to be easily fixed, but the present invention is not limited thereto. The controller and the image capturing device 15 can be connected in the same manner as described above, and will not be described herein.

In an embodiment, the image capturing device 1 may further include at least one collimator (not shown). The collimator may include an optical fiber array, a grating or a microstructure, or a combination thereof (e.g., an optical layer of a microlens and collimator stack), but the invention is not limited thereto. For example, a collimator may be disposed between the illumination element 14 and the light guide plate 10 to cause the light beams emitted from the illumination element 14 to enter the light guide plate 10 at a specific incident angle. On the other hand, the collimator may be disposed between the image capturing element 15 and the light guide plate 10 to cause the light beam with the biological information to enter the image capturing element 15 at a specific incident angle and reduce noise and crosstalk. In an embodiment, the illumination elements 14 may be illumination elements having a narrow divergence angle, and the collimator disposed between the illumination elements 14 and the light guide plate 10 may be omitted.

Fig. 3 to 6 are schematic partial cross-sectional views of image capturing devices 1A, 1B, 1C and 1D according to second to fifth embodiments of the present invention. Referring to fig. 3, the main differences between the image capturing device 1A of the second embodiment and the image capturing device 1 of fig. 2 are described as follows. In the image capturing apparatus 1A, the illuminating element 14 is located beside one of the third surfaces S3. For example, the illumination element 14 is located beside the third surface S3 away from the image capturing element 15.

In an embodiment, the image capturing device 1A may further include at least one collimator (not shown). For example, a collimator may be disposed between the illumination element 14 and the light guide plate 10 to cause the light beams emitted from the illumination element 14 to enter the light guide plate 10 at a specific incident angle. On the other hand, a collimator may be disposed between the image capturing element 15 and the light guide plate 10 to cause the light beam with the biological information to enter the image capturing element 15 at a specific incident angle. In an embodiment, the illumination elements 14 may be illumination elements having a narrow divergence angle, and the collimator disposed between the illumination elements 14 and the light guide plate 10 may be omitted.

Referring to fig. 4, the main differences between the image capturing device 1B of the third embodiment and the image capturing device 1 of fig. 2 are described as follows. In the image-taking apparatus 1B, the first light-transmitting layer 11B includes a plurality of light-transmitting patterns 110 spaced apart from each other. In addition, the image capturing device 1B further includes a fourth light transmitting layer 17 disposed on the first surface S1, wherein the fourth light transmitting layer 17 overlaps the light transmitting region R1 and the light transmitting region R2 in the normal direction Z.

For example, the light-transmitting pattern 110 may be a stripe pattern, wherein the stripe pattern may be disposed along a direction Y perpendicular to the normal direction Z, and the stripe pattern extends along the direction X respectively, but the invention is not limited thereto. There is a gap G between any two adjacent stripe patterns, and the gap G between the stripe patterns is disposed along the direction Y and extends along the direction X, but the present invention is not limited thereto.

Fourth euphotic layer 17 can be disposed on first euphotic layer 11B and light guide plate 10 not covered by first euphotic layer 11B, make first euphotic layer 11B be located between fourth euphotic layer 17 and light guide plate 10, and a part of fourth euphotic layer 17 is located clearance G, but the utility model discloses do not restrict the setting relation between first euphotic layer 11B and fourth euphotic layer 17.

Fourth light-transmitting layer 17 may be transparent, but the light transmittance of fourth light-transmitting layer 17 is not limited to 100%. For example, the fourth transparent layer 17 may be made of acryl, epoxy resin or optical transparent adhesive, but the present invention is not limited thereto.

The light beam in the light guide plate 10 may be transmitted from the first surface S1 of the light guide plate 10 not covered by the light-transmitting pattern 110 but covered by the fourth light-transmitting layer 17. That is, the light beam in the light guide plate 10 may be emitted from the first surface S1 of the light guide plate 10 overlapping with the gap G in the normal direction Z. Since the light beams having different angles are transmitted to different portions of the first surface S1, the light beams having large angles can be filtered (transmitted from the light guide plate 10) by adjusting the position of the gap G. For example, the gap G closest to the illumination element 14 may be designed to filter the light beam having a divergence angle of ± 8 °, the gap G located in the middle may be designed to filter the light beam having a divergence angle of ± 7 °, and the gap G closest to the image capturing element 15 may be designed to filter the light beam having a divergence angle of ± 6 °. However, the number of gaps G and the light beams filtered by each of the gaps G may vary as desired. Further, the amount of the light beam transmitted from the light guide plate 10 can be adjusted by adjusting the size of the gap G. In one embodiment, the gap G may have different widths WG along the direction Y, but the invention is not limited thereto.

In an embodiment, since the light beam having a large angle is filtered through the gap G, the illumination element 14 may be an illumination element having a wide divergence angle, and the collimator disposed between the illumination element 14 and the light guide plate 10 may be omitted.

Referring to fig. 5, the main differences between the image capturing device 1C of the fourth embodiment and the image capturing device 1B of fig. 4 are described as follows. In the image capturing apparatus 1C, the illuminating element 14 is located beside one of the third surfaces S3. For example, the illumination element 14 is located beside the third surface S3 away from the image capturing element 15.

In an embodiment, since the light beam having a large angle is filtered through the gap G, the illumination element 14 may be an illumination element having a wide divergence angle, and the collimator disposed between the illumination element 14 and the light guide plate 10 may be omitted.

Referring to fig. 6, the main differences between the image capturing device 1D of the fifth embodiment and the image capturing device 1 of fig. 2 are described as follows. In the image capturing device 1D, the surface S13D of the third light-transmitting layer 13D pressed by the object OBJ has a recess D, and the second light-transmitting layer 12 is located in the recess D, so that the third light-transmitting layer 13D is located between the second light-transmitting layer 12 and the light guide plate 10.

The relationship between the second light-transmitting layer 12 and the third light-transmitting layer 13 in the second to fourth embodiments can also be modified as described above, and detailed description thereof is omitted here.

Fig. 7 is a schematic top view of an image capturing device 1E according to a sixth embodiment of the present invention, fig. 8 is a schematic partial cross-sectional view of the image capturing device 1E according to the sixth embodiment of the present invention, and fig. 9 is a schematic partial cross-sectional view of an image capturing device 1F according to a seventh embodiment of the present invention.

Referring to fig. 7 to 9, the main differences between the image capturing apparatus 1E of the sixth embodiment (or the image capturing apparatus 1F of the seventh embodiment) and the image capturing apparatus 1B of fig. 4 are described as follows. In the image capturing device 1E (or the image capturing device 1F), the image capturing element 15 may be located below the carrier plate 16 (as shown in fig. 8) or inside the carrier plate 16 (as shown in fig. 9) to facilitate the design of a narrow frame. In this configuration, the light reflected by the object OBJ passes through the third transparent layer 13, the light guide plate 10, the fourth transparent layer 17 and the carrier 16 in sequence, and then is transmitted to the image capturing device 15. In order to avoid shielding carrier plate 16 from the light beam, carrier plate 16 is preferably a transparent carrier plate, but the light transmittance of carrier plate 16 is not limited to 100%. For example, the carrier 16 may be a transparent cover plate, a transparent back plate or a transparent display panel. In the case that the carrier 16 is an organic light emitting display panel, the image capturing device 15 may be located in the display region R3 of the organic light emitting display panel.

In one embodiment shown in fig. 8 and 9, the light reflected by the object OBJ can be transmitted to the image capturing device 15 without total reflection. Therefore, the light transmitting region R1 may be located only at one side of the light transmitting region R2. In a corresponding case, the second light-transmitting layer 12E and the first light-transmitting layer 11E are located in the light-transmitting region R1, and the second light-transmitting layer 12E and the first light-transmitting layer 11E are not necessarily disposed between the light-transmitting region R2 and the image capturing element 15.

In one embodiment, first transparent layer 11E may be a continuous transparent layer, as shown in fig. 2. In an embodiment, the lighting element 14 may be located beside one of the plurality of third surfaces S3, as shown in fig. 3. In an embodiment, the arrangement relationship between the second light-transmitting layer 12E and the third light-transmitting layer 13 may be modified as shown in fig. 6.

Fig. 10 is a schematic top view of an image capturing device 1G according to an eighth embodiment of the present invention. Referring to fig. 10, the main differences between the image capturing apparatus 1G of the eighth embodiment and the image capturing apparatus 1 of fig. 1 are described as follows. The image capturing device 1G includes a plurality of illuminating elements 14 and a plurality of image capturing elements 15. For example, a plurality of illuminating elements 14 are disposed along the direction X, and a plurality of image capturing elements 15 are also disposed along the direction X. In fig. 10, the number of the plurality of illuminating elements 14 and the number of the plurality of image capturing elements 15 are four each. However, the arrangement of the plurality of illuminating elements 14, the arrangement of the plurality of image capturing elements 15, the number of the plurality of illuminating elements 14 and the number of the plurality of image capturing elements 15 may be changed as needed. With the increase of the illumination device 14 and the image capturing device 15, a better resolution and a larger image capturing range can be obtained.

Fig. 11 is a schematic partial cross-sectional view of an image capturing device 1H according to a ninth embodiment of the present invention. Referring to fig. 11, the main differences between the image capturing apparatus 1H of the ninth embodiment and the image capturing apparatus 1 of fig. 2 are described as follows. In the image capturing device 1H, the illuminating element 14 is located below the first surface S1, and the image capturing device 1H further includes a light guiding element 18 located between the illuminating element 14 and the light guide plate 10.

The light guide member 18 is adapted to guide the light beams emitted from the illumination elements 14 to the light guide plate 10 so that the light beams can be transmitted in the light guide plate 10 by total reflection. In other words, the arrangement of the light guiding member 18 helps to increase the light utilization rate and the proportion of the light beam received by the image pickup element 15.

Fig. 12 is a partially enlarged view of the light guiding element 18 and the lighting element 14 in fig. 11. Referring to fig. 11 and 12, the light guiding element 18 may include a main body 180, a plurality of microstructures 182, and an optical layer 184.

The body 180 has a first portion P1 and a second portion P2, wherein the second portion P2 is connected to the first portion P1 and is located between the first portion P1 and the first light transmitting layer 11. A plurality of microstructures 182 are disposed on the first portion P1. The cross-sectional shape of each of the plurality of microstructures 182 may be isosceles triangle, scalene triangle or scalene semiellipse (not shown), but the present invention is not limited thereto. In other derivative variant embodiments, the cross-sectional shape of each of the plurality of microstructures 182 can be elliptical, semi-elliptical, or approximately ear shaped. In the case of a scalene triangle having a cross-sectional shape with a first side SS1 and a second side SS2, the second side SS2 is connected to the first side SS1 and is located between the first side SS1 and the second portion P2, the length of the first side SS1 may be less than or equal to the length of the second side SS2, and the angle α between the first side SS1 and the normal NL perpendicular to the first portion P1 is less than the angle β between the second side SS2 and the normal NL. For example, the plurality of microstructures 182 may be prisms or triangular prisms. The triangular columns may be disposed along the direction Y and extend along the direction X, but the present invention is not limited thereto.

The cross-sectional shape of each of the plurality of microstructures is a scalene semi-ellipse (not shown), the scalene semi-ellipse having a first side and a second side, the second side being connected to the first side and located between the first side and the second portion, the length of the first side being less than or equal to the length of the second side, and an angle between the first side and a normal perpendicular to the first portion being less than an angle between the second side and the normal.

In one embodiment, the sum of the thickness TP1 of the first portion P1 and the thickness T182 of each of the plurality of microstructures 182 is less than or equal to the thickness TP2 of the second portion P2. In addition, the main body 180 and the plurality of microstructures 182 may be integrally formed, but the present invention is not limited thereto. The material of the main body 180 and the material of the plurality of microstructures 182 may be plastic, but the present invention is not limited thereto. The refractive index of the main body 180 and the refractive index of the plurality of microstructures 182 may be 1.58 to 1.59, but the present invention is not limited thereto.

The optical layer 184 is disposed on the plurality of microstructures 182. The optical layer 184 may be a reflective layer. Alternatively, the optical layer 184 may be a transparent layer having a refractive index higher than the refractive index of each of the body 180 and the plurality of microstructures 182. With the optical layer 184 disposed, at least a portion of the light beam transmitted to the microstructures 182 (e.g., light beam B) may be reflected back to the second portion P2. That is, the optical layer 184 helps to reduce the probability of the light beam passing through the plurality of microstructures 182.

In an embodiment, the lighting element 14 is not attached to the light directing element 18, and an air gap AG is located between the light directing element 18 and the lighting element 14. In the case where the air gap AG exists, the light beam B reflected at the interface between the microstructure 182 and the optical layer 184 and then transferred to the interface between the body 180 and the air gap AG may be reflected due to total reflection, which may enter the light guide plate 10 and be used for biological recognition.

In any embodiment in which the lighting elements 14 are located below the first surface S1, the light guide element 18 may be further included, and the collimator (not shown) disposed between the lighting elements 14 and the light guide plate 10 may be omitted.

Fig. 13 is a partial cross-sectional view of an image capturing device 1I according to a tenth embodiment of the present invention. Referring to fig. 13, the main differences between the image capturing device 1I of the tenth embodiment and the image capturing device 1H of fig. 11 are described as follows.

The image capturing device 1I further includes a first adhesive layer 19. The light guiding element 18 is adhered to the first surface S1 by the first adhesive layer 19. In one embodiment, the first adhesive layer 19 overlaps the optical layer 184 (as shown in fig. 12) and the second portion P2 in the normal direction Z, but the invention is not limited thereto. In one embodiment, the first adhesive layer 19 may overlap the second portion P2 in the normal direction Z but not overlap the optical layer 184 (as shown in fig. 12) in the normal direction Z.

The first adhesive layer 19 is designed to allow the passage of the light beam and to avoid the formation of total reflection at the interface between the first adhesive layer 19 and the second portion P2. In the case where the first adhesive layer 19 overlaps the second portion P2 in the normal direction Z but does not overlap the optical layer 184 (as shown in fig. 12) in the normal direction Z, the refractive index of the first adhesive layer 19 may be higher or slightly less than the refractive index that the body 180 and each of the plurality of microstructures 182 have. In the case where the first adhesive layer 19 overlaps with the optical layer 184 (as shown in fig. 12) and the second portion P2 in the normal direction Z, the optical layer 184 may be a light-transmitting layer having a refractive index higher than that of the first adhesive layer 19; alternatively, the optical layer 184 may be a reflective layer.

The image capturing device 1I may further include a second adhesive layer 20. The illumination element 14 may be adhered to the light directing element 18 by a second adhesive layer 20. The refractive index of the second adhesive layer 20 may be less than that of each of the body 180 and the plurality of microstructures 182 (as shown in fig. 12), so that the light beam B reflected at the interface between the microstructures 182 and the optical layer 184 and then transmitted to the interface between the body 180 and the air gap AG may be reflected due to total reflection, which may enter the light guide plate 10 and be used for biological recognition.

In any embodiment in which the lighting element 14 is located below the first surface S1, the light guiding element 18 and at least one of the first adhesive layer 19 and the second adhesive layer 20 may be further included, and the collimator (not shown) disposed between the lighting element 14 and the light guide plate 10 may be omitted.

Fig. 14 is a partial cross-sectional schematic view of a light guide element 18A and a lighting element 14 according to an embodiment of the invention. Referring to fig. 14, the main differences between the light guiding element 18A and the light guiding element 18 in fig. 12 are described as follows. The main body 180A has a groove NT at least partially overlapping the plurality of microstructures 182, and the illumination element 14 is located in the groove NT. With the design in which the groove NT at least partially overlaps with the plurality of microstructures 182, the transmission path of the light beam transmitted to the second portion P2 can be prevented from being influenced by the groove NT or the illumination element 14 located in the groove NT.

In one embodiment, the groove NT is located only in the first portion P1A of the body 180A. However, the groove NT may be located in both the first and second portions P1A and P2.

In any embodiment where the lighting element 14 is located below the first surface S1, the light guiding element 18A may be further included, and the arrangement relationship between the light guiding element 18A and the lighting element 14 may be modified as described above. In addition, at least one of the first adhesive layer 19 and the second adhesive layer 20 in fig. 13 may be further included.

Fig. 15 is a schematic partial cross-sectional view of an image capturing device 1J according to an eleventh embodiment of the present invention. Referring to fig. 15, the main differences between the image capturing device 1J of the eleventh embodiment and the image capturing device 1H of fig. 11 are described as follows. In the image pickup device 1J, a light guide member 18B is included between the illumination member 14 and the light guide plate 10. The difference between the light directing element 18B and the light directing element 18 in fig. 11 is: the light guiding member 18B has a slit ST. The light guide member 18B may be, for example, a black matrix, and has a slit ST that allows light rays having a specific wavelength or having a specific incident angle to pass therethrough. In one embodiment, the light guiding element 18B has a slit ST in the vertical projection direction of the illuminating element 14, and the transmittance of the light guiding element 18B to the illuminating element 14 is preferably less than 1%. The shape of the light guiding element 18B may be a strip, but the invention is not limited thereto. In addition, in other embodiments, the light guiding element 18B may be further disposed between the image capturing element 15 and the light guide plate 10.

Fig. 16 is a schematic top view of an image capturing device 1K according to a twelfth embodiment of the present invention. Referring to fig. 16, the main differences between the image capturing apparatus 1K of the twelfth embodiment and the image capturing apparatus 1 of fig. 1 are described as follows. The image capturing device 1K includes two illuminating elements 14 and one image capturing element 15. The two illumination elements 14 may emit light beams having different wavelengths or having different angles of incidence (total reflection angles). Furthermore, the two illumination elements 14 may emit light beams at different times to avoid cross talk. The images taken by the image-taking device 15 at different times may be combined to form an image that is larger than a single image taken at different times. Thus, the image capturing device 1J can have a better resolution and a larger image capturing range.

Fig. 17 is a schematic top view of an image capturing device 1L according to a thirteenth embodiment of the present invention. Referring to fig. 17, the main differences between the image capturing device 1L of the thirteenth embodiment and the image capturing device 1 of fig. 2 are described as follows. The third surface S3 on the lighting element 14 is a curved surface (i.e., a portion of the light guide plate 10K has a curved surface) connected between the first surface S1 and the second surface S2 so as to reflect light from the lighting element 14 to the light penetration region R2. Thus, light directing elements (such as the light directing elements 18 described above) may be omitted. In another embodiment, the third surface S3 on the lighting element 14 may also be a slope connecting between the first surface S1 and the second surface S2. In other embodiments, a reflective layer (not shown) may be formed on the third surface S3. The material of the reflective layer may comprise a metal, an alloy, a metal oxide, a metal nitride, a metal oxynitride, a polymer, or a combination of at least two of the foregoing, or other material suitable for reflecting light. The method for forming the reflective layer on the third surface S3 may include coating, printing, or other similar processes. In any embodiment where the lighting element 14 is located below the first surface S1, the third surface S3 located on the lighting element 14 may be modified as described above.

In view of the above, by disposing two light-transmitting layers (e.g., the first light-transmitting layer and the second light-transmitting layer) with low reflectivity on two sides of the light guide plate, most of the light beams can be transmitted through the light guide plate by total reflection. In addition, by the design that the second light-transmitting layer is not overlapped with the light-transmitting area and the third light-transmitting layer is overlapped with the light-transmitting area, the light beam transmitted in the light guide plate can be transmitted to the surface of the third light-transmitting layer pressed by the object to be measured, and the light beam reflected by the object to be measured can return to the light guide plate after passing through the third light-transmitting layer and then is transmitted to the image capturing element through total reflection. Therefore, the messy light beam that the reducible component of getting for instance received, just the utility model discloses a get for instance the device and have good discernment ability.

In one embodiment, the first light-transmitting layer may include a plurality of light-transmitting patterns separated from each other to filter light beams having a large angle. In an embodiment, the image capturing element may be located below the carrier or inside the carrier, so as to facilitate the design of the narrow frame. In one embodiment, the number of at least one of the illuminating device and the image capturing device can be increased to obtain a better resolution and a larger image capturing range. In one embodiment, a light guiding device may be further included to increase the light utilization and the ratio of the light beams received by the image capturing device. In one embodiment, at least one adhesive layer may be disposed between the light guide member and the light guide plate or between the light guide member and the illumination member, and the reflectivity of the at least one adhesive layer may be designed to avoid interface reflection. In one embodiment, the illumination element may be located in a groove of the main body, and the groove at least partially overlaps with the plurality of microstructures to avoid affecting the transmission path of the light beam. In one embodiment, the third surface on the illumination element may also be a curved surface or an inclined surface to reflect light from the illumination element to the light penetration region, and thus, the light guiding element may be omitted.

Although the present invention has been described with reference to the above embodiments, those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (25)

1. An image capturing device at least comprises an illuminating element for providing a light beam to irradiate an object to be measured and an image capturing element for receiving a signal light beam with the object to be measured, and is characterized in that: the image capturing apparatus further includes:

a light guide plate having a first surface, a second surface, and a plurality of third surfaces, wherein the second surface is opposite to the first surface, and each of the plurality of third surfaces connects the first surface to the second surface;

a first light-transmitting layer disposed on one side of the first surface;

a second light-transmitting layer disposed on one side of the second surface, wherein the second light-transmitting layer overlaps with the light-transmitting region of the light guide plate in a normal direction of the light guide plate, and the second light-transmitting layer does not overlap with the light-transmitting region of the light guide plate in the normal direction; and

and a third light-transmitting layer disposed on one side of the second surface and overlapping the light transmitting region and the light penetrating region in the normal direction, wherein a refractive index of the third light-transmitting layer is higher than a refractive index of the first light-transmitting layer and a refractive index of the second light-transmitting layer, and a refractive index of the light guide plate is higher than a refractive index of the first light-transmitting layer and a refractive index of the second light-transmitting layer.

2. The image capturing device as claimed in claim 1, wherein the refractive index of the first light transmitting layer is greater than 1 and less than or equal to 1.45, the refractive index of the second light transmitting layer is greater than 1 and less than or equal to 1.45, and the refractive index of the third light transmitting layer is greater than or equal to 1.5.

3. The image capturing device of claim 1, wherein the first light transmitting layer comprises a multi-layer structure, and an average refractive index of the first light transmitting layer is greater than 1 and less than or equal to 1.45.

4. The image capturing device as claimed in claim 1, wherein a refractive index difference between the light guide plate and the third light transmissive layer is less than 0.1.

5. The image capturing device as claimed in claim 1, wherein the difference between the refractive indices of the light guide plate and the first light-transmitting layer is greater than or equal to 0.05, and the difference between the refractive indices of the light guide plate and the second light-transmitting layer is greater than or equal to 0.05.

6. The image capturing device as claimed in any one of claims 1 to 5, wherein the second light transmitting layer has an opening that overlaps with the light transmitting region of the light guide plate in the normal direction.

7. The image capturing device as claimed in any one of claims 1 to 5, wherein the first light transmissive layer comprises a plurality of light transmissive patterns separated from each other, and the image capturing device further comprises:

a fourth light-transmitting layer disposed on the one side of the first surface, wherein the fourth light-transmitting layer overlaps with the light-transmitting region and the light-penetrating region in the normal direction.

8. The image capturing apparatus as claimed in claim 1, further comprising:

and the carrier plate is positioned between the light guide plate and the carrier plate, and the carrier plate is a cover plate, a back plate or a display panel.

9. The image capturing apparatus of claim 8, wherein the image capturing device is located under the carrier or inside the carrier, and the carrier is a transparent carrier.

10. The image capturing apparatus as claimed in claim 8 or 9, wherein the carrier is an organic light emitting display panel, and the image capturing device is located in a display area of the organic light emitting display panel.

11. The image capturing device as claimed in claim 1, wherein the illuminating element is located below the first surface, and the image capturing device further comprises:

a light guide member between the illumination member and the light guide plate.

12. The image capturing apparatus of claim 11, wherein the light guiding element comprises:

a body having a first portion and a second portion, wherein the second portion is connected to the first portion and is located between the first portion and the first light-transmissive layer;

a plurality of microstructures disposed on the first portion; and

and the optical layer is arranged on the plurality of microstructures.

13. The image capturing device of claim 12, wherein the optical layer is a reflective layer or a light transmissive layer, wherein the light transmissive layer has a refractive index higher than a refractive index of each of the main body and the plurality of microstructures.

14. The image capturing apparatus of claim 12, wherein a sum of a thickness of the first portion and a thickness of each of the plurality of microstructures is less than or equal to a thickness of the second portion.

15. The image capturing apparatus of claim 12, wherein the main body is integrally formed with the plurality of microstructures.

16. The image capturing apparatus as claimed in claim 12, wherein each of the plurality of microstructures has a cross-sectional shape of an isosceles triangle, a scalene triangle or a scalene semi-ellipse.

17. The image capturing apparatus as claimed in claim 16, wherein the cross-sectional shape of each of the plurality of microstructures is a scalene triangle having a first side and a second side connected to the first side and located between the first side and the second portion, the length of the first side is less than or equal to the length of the second side, and an angle between the first side and a normal perpendicular to the first portion is smaller than an angle between the second side and the normal.

18. The image capturing apparatus of claim 12, further comprising:

a first adhesive layer, wherein the light guiding element is adhered to the first surface by the first adhesive layer, the first adhesive layer overlaps with the optical layer and the second portion in the normal direction, and wherein the optical layer is a reflective layer or a light-transmitting layer, the light-transmitting layer having a refractive index higher than that of the first adhesive layer.

19. The image capturing apparatus of claim 12, wherein an air gap is provided between the light guiding element and the illuminating element.

20. The image capturing apparatus of claim 12, further comprising:

a second adhesive layer, wherein the illumination element is adhered to the light-guiding element by the second adhesive layer, and the second adhesive layer has a refractive index lower than a refractive index of each of the body and the plurality of microstructures.

21. The image capturing apparatus of claim 12, wherein the main body has a recess at least partially overlapping the plurality of microstructures, and the illumination element is located in the recess.

22. The image capturing apparatus of claim 1, wherein the third surface on the illuminating element is a curved surface or an inclined surface.

23. The image capturing apparatus of claim 1, wherein the illumination element is disposed on one side of the first surface or one of the third surfaces.

24. The image capturing device as claimed in claim 1, wherein the image capturing element is located at one side of the first surface.

25. The image capturing apparatus of claim 16, wherein the cross-sectional shape of each of the plurality of microstructures is the scalene semi-ellipse, the scalene semi-ellipse having a first side and a second side, the second side being connected to the first side and located between the first side and the second portion, the first side having a length less than or equal to a length of the second side, and an angle between the first side and a normal perpendicular to the first portion being less than an angle between the second side and the normal.

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