JP7460392B2 - Optical Sensor Device - Google Patents

Description

The present invention relates to a collimator and a high-resolution optical sensor device equipped with a collimator.

Optical sensors that use photoelectric conversion are used not only for image recognition but also in fields such as biometric authentication, and their applications are expanding. When using optical sensors, the resolution related to the angle of incidence of light becomes an issue. By placing a collimator on the light receiving surface side of the optical sensor, it is possible to improve the resolution related to the angle of incidence of light.

However, if the holes in the collimator, that is, the light guide part of the collimator, and the sensor elements of the optical sensor are not aligned accurately, the output will vary from sensor element to sensor element even if the same intensity of light enters, resulting in accurate Unable to perform measurements. Patent Document 1 discloses that instead of making each sensor element correspond to one collimator hole, each sensor element is made to correspond to a plurality of holes, thereby solving problems caused by alignment between the optical sensor device and the collimator. The configuration to take measures is described.

JP 2019-3650 A

In order to improve spatial resolution by disposing a collimator on the display surface of an optical sensor device, it is necessary to increase the aspect ratio of the collimator. The aspect ratio of a collimator is defined by the ratio of the hole in the collimator, ie, the diameter of the light guide in a plane, to the depth of the light guide. In other words, the smaller the diameter of the light guiding portion and the larger the depth, the larger the aspect ratio can be.

However, it is difficult to form holes, i.e. light guides, that are small in diameter and deep. In particular, if the pitch of the sensor elements is reduced to increase resolution, it becomes even more difficult to form deep holes at high density.

The objective of the present invention is to realize a configuration that enables a collimator with a large aspect ratio to be mounted on an optical sensor device.

The present invention aims to solve the above problems, and the main specific means are as follows:

(1) An optical sensor device having a light receiving device, a collimator, and a light emitting device, the collimator being disposed between the light receiving device and the light emitting device, the collimator being configured by stacking multiple layers including a first collimator and a second collimator, the first collimator and the second collimator being configured by forming holes through which light passes in a light blocking resin, and the optical sensor device being configured such that, when n is an integer of 4 or more, the first hole formed in the first collimator is an n-sided polygon in plan view, and the second hole formed in the second collimator is centered at the same center as the first hole and is rotated 360 degrees/2n with respect to the first hole.

(2) An optical sensor device having a light receiving device, a collimator, and a light emitting device, the collimator being disposed between the light receiving device and the light emitting device, the collimator being configured by stacking multiple layers including a first collimator and a second collimator, the first collimator being configured by forming a transparent resin in a first hole that allows light to pass through the light blocking resin, the second collimator being configured by forming a second hole that allows light to pass through the light blocking resin, and the optical sensor device being configured such that, when n is an integer of 4 or more, the first hole formed in the first collimator is an n-sided polygon in plan view, and the second hole formed in the second collimator is centered at the same center as the first hole and is rotated 360 degrees/2n with respect to the first hole.

(3) An optical sensor device having a light receiving device, a collimator, and a light emitting device, the collimator is disposed between the light receiving device and the light emitting device, the substrate of the light emitting device is formed of a transparent resin, the collimator faces the substrate of the light emitting device, the collimator is configured by stacking multiple layers including a first collimator and a second collimator, the first collimator and the second collimator are configured by forming holes through which light passes in a light blocking resin, and when n is an integer of 4 or more, the first hole formed in the first collimator is an n-sided polygon in a plan view, the second hole formed in the second collimator has the same center as the first hole and is rotated 360 degrees/2n with respect to the first hole, and the second hole is made of a transparent resin of the same material as the substrate of the light emitting device. An optical sensor device characterized in that the second hole is made of a transparent resin of the same material as the substrate of the light emitting device.

FIG. 2 is a cross-sectional view of the optical sensor device. FIG. FIG. 2 is a sectional view of the optical sensor device showing a detailed cross section of the light receiving device. FIG. 2 is a plan view of a light emitting device. FIG. 2 is a circuit diagram of a light emitting element. FIG. 2 is a cross-sectional view of the optical sensor device showing a detailed cross section of the light-emitting device. FIG. 3 is a perspective view of a collimator. FIG. 13 is a perspective view of another example of a collimator. FIG. 9 is a plan view of the collimator of FIG. 8 . This is a cross-sectional view taken along line AA in FIG. 9 is a plan view illustrating a problem with the collimator shown in FIG. 8. FIG. 12 is a sectional view taken along line BB in FIG. 11. 12 is a sectional view taken along the line CC in FIG. 11. FIG. 1 is a plan view showing a configuration of a first embodiment. 15 is a sectional view taken along line DD in FIG. 14. FIG. 15 is a sectional view taken along line EE in FIG. 14. FIG. 15 is a sectional view taken along the line FF in FIG. 14. FIG. FIG. 2 is a cross-sectional view of a collimator having a three-layer structure. FIG. 2 is a cross-sectional view of a collimator having a four-layer structure. FIG. 3 is a plan view of a light receiving element, a light emitting element, and a collimator arranged in a delta arrangement. FIG. 13 is a plan view showing a configuration example of a second embodiment. 22 is a sectional view taken along line GG in FIG. 21. FIG. This is a cross-sectional view taken along line HH of Figure 21. FIG. 3 is a cross-sectional view showing a state in which a photosensitive black resin forming the first layer of the collimator is applied. FIG. 3 is a cross-sectional view of a first layer collimator. FIG. 7 is a cross-sectional view showing a state in which a photosensitive black resin forming the second layer of the collimator is applied. It is a sectional view showing the residue of photosensitive black resin. FIG. 7 is a cross-sectional view showing a process according to a first embodiment of Example 3; FIG. 11 is a cross-sectional view showing a first embodiment of the third embodiment. FIG. 7 is a cross-sectional view showing a process according to a second embodiment of Example 3; 26B is a cross-sectional view showing a process subsequent to FIG. 26A. FIG. 7 is a cross-sectional view showing a second form of Example 3. FIG. 7 is a cross-sectional view showing a process for forming a three-layer collimator according to a second embodiment of Example 3; FIG. 13 is a cross-sectional view showing the configuration of a three-layer collimator according to a second embodiment of the present invention. 11A to 11C are cross-sectional views showing a process according to a third embodiment of the present invention. FIG. 11 is a cross-sectional view showing a third embodiment of the present invention. 13A to 13C are cross-sectional views showing a process for forming a collimator having a three-layer structure according to a third embodiment of the present invention. FIG. 7 is a cross-sectional view showing the configuration of a three-layer collimator according to a third embodiment of Example 3. FIG. 13 is a cross-sectional view showing the influence of the refractive index in a collimator. FIG. 7 is a cross-sectional view showing the influence of refractive index when transparent resin is present in a part of the collimator. 11A to 11C are cross-sectional views showing a process according to a first embodiment of Example 4. A cross-sectional view showing a process following FIG. 30A. FIG. 30B is a cross-sectional view showing a process following FIG. 30B. FIG. 13 is a cross-sectional view showing the configuration of a collimator according to a first embodiment of the present invention. FIG. 7 is a cross-sectional view showing a process according to a second embodiment of Example 4. FIG. 31B is a cross-sectional view showing a process following FIG. 31A. FIG. 13 is a cross-sectional view showing the configuration of a collimator according to a second embodiment of the present invention. FIG. 7 is a cross-sectional view showing a process according to a third embodiment of Example 4. FIG. 32B is a cross-sectional view showing a process subsequent to FIG. 32A. FIG. 13 is a cross-sectional view showing the configuration of a collimator according to a third embodiment of the present invention.

The contents of the present invention will be explained in detail below using Examples.

FIG. 1 is a sectional view showing an optical sensor device according to the present invention. In the configuration of FIG. 1, a collimator 20 is placed on a light receiving device 10, and a light emitting device 30 is placed on top of the collimator 20. The upper surface of the light emitting device 30 is protected by a protective glass 34 , and the object to be measured 40 is placed on the protective glass 34 . In the case of a finger authentication device, the object to be measured 40 is a human finger.

In FIG. 1, the light receiving device 10 has a plurality of light receiving elements 11 formed on a first substrate 100, and a first protective film 12 formed to cover the light receiving elements 11. A collimator 20 is disposed on the first protective film 12. The collimator 20 is formed of holes 21 (hereinafter referred to as holes) that serve as light guides and black light-shielding resin 22. The holes 21 of the collimator 20 are formed to correspond to the light receiving elements 11 of the light receiving device 10. In FIG. 1, the collimator 20 is formed continuously on the light receiving device 10.

A light emitting device 30 is formed on the collimator 20. The light emitting device 30 has a structure in which a plurality of light emitting elements 32 are formed on a second substrate 200, and a second protective film 33 is formed to cover the light emitting elements 32. The light emitting element 32 is not formed in the hole 21 of the collimator 20 when viewed in plan, but is formed in a portion corresponding to the light shielding resin 22. A protective substrate 34 made of glass or the like is formed on the second protective film 33 .

In FIG. 1, an object to be measured 40 is placed on a protective substrate 34. As shown in FIG. In the case of a finger authentication system, the object to be measured 40 is a human finger. Light emitted from the light emitting element 32 in the light emitting device 30 is reflected by the object to be measured 40, passes through the hole 21 of the collimator 20, and is detected by the light receiving element 11 of the light receiving device 10. The larger the aspect ratio of the collimator 20, the higher the resolution can be.

For image detection in the optical sensor device shown in FIG. 1, the photocurrent may be detected by scanning the light receiving surface in the light receiving device 10, or may be detected by scanning light in the light emitting device 30. . When the photocurrent is scanned and detected in the light receiving device 10, it is not necessarily necessary to provide a switching element for each light emitting element 32 in the light emitting device 30, and it is sufficient to uniformly turn on and off all the light emitting elements. On the other hand, when scanning light in the light emitting device 30, it is not necessarily necessary to provide a switching element in each light receiving element 11 in the light receiving device 10. However, in order to improve detection accuracy, the light receiving device 10 and the light emitting device 30 may be scanned simultaneously to extract signals.

FIGS. 2 and 3 are examples of a case where the light receiving device 10 scans the light receiving elements 11 formed in a matrix to detect a signal. FIG. 2 is an equivalent circuit showing the configuration of 10 of the light receiving device. In FIG. 2, light receiving elements 11 are formed in a matrix on a first substrate 100. As shown in FIG. The first substrate 100 has, for example, a horizontal diameter xx of 3 cm and a vertical diameter yy of 3 cm. On the first substrate 100, scanning lines 51 extend in the horizontal direction (x direction) and are arranged in the vertical direction (y direction). The detection line 52 and the power supply line 53 extend vertically and are arranged horizontally. The area surrounded by the scanning line 51 and the detection line 52 or the scanning line 51 and the power supply line 53 serves as the light receiving element 11. A switching TFT (Thin Film Transistor) 16, a PIN photodiode 15, and a storage capacitor 17 are formed in each light receiving element 11. One electrode of the storage capacitor 17 is connected to the source of the TFT 16, and the other electrode is connected to, for example, a reference potential.

A scanning line drive circuit 55 is arranged in the horizontal direction outside the sensor area, a power supply circuit 57 is arranged in the upper direction, and a detection circuit 56 is arranged in the lower direction. The scanning line drive circuit 55 and the detection circuit 56 are formed of TFTs. A shift register in the scanning line drive circuit 55 sequentially selects the scanning lines 51 from above.

The power supply line 53 is connected to the anode of each photodiode 15, extends in the vertical direction, and is connected to the same power supply in a power supply circuit 57 above the sensor area. Then, an anode potential is supplied to the power supply line 53. The detection line 52 is connected to the drain of the switching TFT 16, and the source of the switching TFT 16 is connected to the cathode of the photodiode 15. The detection line 52 extends downward from each light receiving element 54, and a detection circuit 56 detects the photocurrent. In FIG. 2, when a light receiving element selected by a scanning line 51 is irradiated with light, a photocurrent is generated in the photodiode 15, and this photocurrent is detected by a detection circuit 56 through a detection line 52. The light receiving element 54 can be randomly accessed by the scanning line 51 and the detection line 52.

Figure 3 is a cross-sectional view showing the state in which the collimator 20 is laminated on the light receiving device 10 of Figure 2. In Figure 3, a base film 101 made of a laminated film of silicon nitride (SiN) and silicon oxide (SiO) is formed on the first substrate 100. This is to prevent impurities from the first substrate 100 from contaminating the semiconductor film 104 that constitutes the TFT. The thickness of the SiO film is, for example, 200 nm, and the thickness of the SiN film is, for example, 20 nm. The first substrate may be a glass substrate or a resin substrate.

A light shielding film 102 is formed of metal on the base film 101. The light shielding film 102 serves as a light shielding film for the TFT formed above. The light shielding film 102 can be used as a shield electrode that prevents the TFT from being affected by charging of the substrate 100 by supplying a predetermined potential, and can also be used as a bottom gate by applying a gate voltage.

An insulating film 103 is formed to cover the light shielding film 102 using a SiO film or a laminated film of an SiO film and a SiN film. A semiconductor film 104 for forming a TFT is formed on the insulating film 103. The semiconductor film 104 can be formed of an oxide semiconductor, polysilicon, a-Si, or the like, and in FIG. 3, an oxide semiconductor is used. For example, IGZO (Indium Gallium Zinc Oxide) is used as the oxide semiconductor. A drain electrode 105 is formed over the drain region of the oxide semiconductor film 104, and a source electrode 106 is formed over the source region.

A second gate insulating film 107 is formed of a SiO film covering the oxide semiconductor 104. Oxygen is supplied from the SiO film to the oxide semiconductor film 104 to stabilize the characteristics of the oxide semiconductor film 104. A gate electrode 108 is formed of metal or an alloy on the second gate insulating film 107. A capacitor electrode 109 for forming a storage capacitor in FIG. 2 is formed on the second gate insulating film 107 at a location different from the TFT.

An interlayer insulating film 110 is formed covering the gate electrode 108 and the capacitance electrode 109. The interlayer insulating film 110 is often a laminated structure of a SiO film and a SiN film. A through hole 121 is formed penetrating the second gate insulating film 107 and the interlayer insulating film 110 to connect the drain wiring (detection line) 111 to the drain electrode 105, and a through hole 122 is formed to connect the source electrode 106 to the contact electrode 112. The drain wiring 112 corresponds to the detection line 52 in FIG. 2.

An organic passivation film 113 is formed covering the drain wiring 111 and the contact electrode 112. The organic passivation film 113 is formed to a thickness of about 2 microns in order to reduce stray capacitance. A through hole 123 is formed in the organic passivation film 113 to connect the contact electrode 112, which is connected to the source electrode 112 of the TFT, to the cathode 123 of the photodiode.

The cathode 114 is formed of Ti on the organic passivation film 113. The cathode 114 is about 100 nm thick and is formed on the organic passivation film 113 and in the through hole 123. A photoconductive film 115 is formed on the cathode 114. The photoconductive film 115 has a PIN structure, in which an n+ layer 1151 is formed on the cathode 114 with a thickness of about 40 nm, an i layer (a-Si layer) 1152 is formed on the n+ layer 1151 with a thickness of 600 nm, and a p+ layer 1153 is formed on the i layer with a thickness of 30 nm. Note that these values of the PIN film 130 are examples. The n+ layer 1151, i layer 1152, and p+ layer 1153 are all formed of a-Si. All of these can be formed continuously by CVD. In addition to silicon, organic semiconductors can also be used.

An ITO (Indium Tin Oxide) film 116 is formed as an anode on the p+ layer 1153, for example, with a thickness of 50 nm. Then, to prevent electrical leakage, a second interlayer insulating film 117 is formed, for example, from SiN. An opening is formed in the second interlayer insulating film 117 on the surface of the anode 116, and the anode potential is supplied from this opening via the anode wiring (power line) 118.

The anode wiring 118 is formed by a laminated structure of a 100 nm thick Ti film, a 300 nm thick aluminum film, and a 100 nm thick Ti film. An inorganic passivation film 119 is formed by, for example, SiN, covering the anode wiring 118, the anode 116, the second interlayer insulating film 117, etc.

In this state, the surface is a SiN film 119 with a thickness of about 200 nm, and therefore does not have sufficient mechanical strength. Therefore, in order to mechanically protect the optical sensor, a transparent organic protective film 120 is formed on the inorganic passivation film 119 using, for example, acrylic resin. Since the transparent organic protective film 120 also serves as a flattening film, it is formed thick, for example, about 2 μm. Although the light receiving device 10 is completed above, it is also possible for the light receiving device 10 to use a configuration other than those shown in FIGS. 2 and 3.

In FIG. 3, the collimator 20 is formed on the transparent protective film 120 of the light receiving device 10. The collimator 20 has a structure in which holes 21, which are light guides, are formed in a light-shielding resin film 22. The material of the light-shielding resin film 22 can be the same as the black matrix used in the display device. If a photosensitive resin is used as the material of the light-shielding resin film 22, the holes 21 can be directly formed in the light-shielding resin film 22 without using a resist. The structure and manufacturing method of the collimator 20 will be described later. Note that the light-shielding resin film is not limited to being black, and may be a film that blocks only light of a specified wavelength. Also, light-shielding means having a transmittance lower than the transmittance of the holes.

A light emitting device 30 is placed on the collimator 20. The light emitting device 30 has a structure in which a light emitting element 32 is formed on a second substrate 200, a protective film 33 is formed to cover this, and a protective substrate 34 is formed thereon. Light L from the light emitting element 30 is reflected by the object to be measured 40 and detected as a photocurrent by the light receiving device 10.

As shown in FIG. 2, the detected photocurrent is taken in as data by a detection circuit 56 through a detection line 52. That is, in the light receiving device 10, necessary data can be acquired by capturing data of each light receiving element while scanning the scanning line 51. Therefore, in the configurations of FIGS. 2 and 3, the light emitting device 30 does not necessarily require a scanning circuit or a detection circuit, and can be operated by uniformly turning on and off each light emitting element 30. It is. In other words, if the light receiving device 10 described in FIGS. 2 and 3 is used, the light emitting device 30 does not necessarily need to have a random access configuration.

Figures 4 to 6 are explanatory diagrams of a configuration for detecting image data by scanning the light-emitting device 30. In other words, Figures 4 to 6 are configurations for allowing random access to the light-emitting device 30. Figures 4 to 6 use a configuration similar to that of an organic EL display device as the light-emitting device 30. However, as shown in Figure 6, a transmissive region 400 is formed in part of the light-emitting layer, and light reflected from the object to be measured 40 is made incident on the light-receiving device 10 from this part.

Figure 4 is a plan view of a light-emitting device 30 having a similar configuration to an organic EL display device. In the light-emitting region 60, scanning lines 61 extend horizontally from a scanning line driving circuit 65 and are arranged vertically. Signal lines 62 extend upward from a signal circuit 66 and are arranged horizontally. Power lines 63 extend downward from a power circuit 67 and are arranged horizontally. Light-emitting elements 32 are formed in an area surrounded by the scanning lines 61 and signal lines 62, or the scanning lines 61 and power lines 63. Each light-emitting element 32 can be randomly accessed by the scanning lines 61 and detection lines 62.

FIG. 5 shows an equivalent circuit of each light emitting element 32. In FIG. 5, a light emitting layer EL made of an organic EL layer is formed in a region surrounded by a scanning line 61 and a signal line 62 or a scanning line 61 and a power supply line 63. In FIG. 5, when a scanning signal is applied to the scanning line 61, the switching TFT (T1) is turned on, and a light emission signal from the signal line 62 is accumulated in the storage capacitor Ch. The drive TFT (T2) supplies current from the power supply line to the light emitting layer EL in accordance with the voltage of the storage capacitor Ch. In FIG. 5, Va is the anode voltage and Vk is the cathode voltage.

FIG. 6 is a cross-sectional view of a case where the light emitting device 30 has a structure similar to that of an organic EL display device. In FIG. 6, a collimator 20 is formed on the light receiving device 10. The light receiving device 10 may be configured with a simple light receiving element 11 without a switching element, or may be configured with a randomly accessible light receiving element 10 as described in FIGS. 2 and 3. The collimator 20 will be explained later.

In FIG. 6, the second substrate 200 is formed on the collimator 20. The second substrate 200 may be glass or a transparent resin such as polyimide. If a transparent resin is used for the second substrate 200, the light emitting device 30 can be formed on the collimator 20 in a continuous process. When the second substrate 30 is formed of a transparent resin, the resin before hardening may flow into the hole 21 of the collimator 20 due to a leveling effect. In this case, the refractive index inside the hole 21 of the collimator 20 becomes that of polyimide. In other words, the light is not refracted between the second substrate 200 and the hole 21 of the collimator 20.

In FIG. 6, the process from the base film 101 to the formation of the drain wiring 111 and the contact electrode 112 on the organic passivation film 140 is the same as in FIG. 3, so the explanation will be omitted.

In FIG. 6, a lower electrode 150 serving as an anode is formed on an organic passivation film 140. The lower layer of the lower electrode 150 is a reflective electrode made of Al or Ag or the like, and the upper layer is an anode made of ITO or the like. A bank 160 having a recess is formed on the lower electrode 150. An organic EL layer 151 serving as a light-emitting layer is formed in the recess of the bank 160.

An upper electrode 152 serving as a cathode is formed on the organic EL layer 151 using a transparent conductive film. The upper electrode 152 is formed in common for each pixel. An inorganic protective film 153 having a silicon nitride film or the like is formed to cover the upper electrode 152. An organic protective film 33 which also serves as a planarizing film or adhesive is formed on the inorganic protective film 153, and a protective substrate 34 made of glass or the like is formed on top of that.

The object to be measured 40 is placed on the protective substrate 34 of the light emitting device 30 . In FIG. 6, an opening 400 is formed near the center of the organic EL layer 151, and light L reflected from the object to be measured 40 and indicated by an arrow passes through the opening 400 and the hole 21 of the collimator 20 to the light receiving device 10. It is now possible to enter. If the light emitting device 10 can be randomly accessed, the light receiving device 10 can be simply turned on and off, or can be randomly accessed as described in FIGS. 2 and 3 as necessary. It's okay. Note that when an organic EL display device used for display is used as the light emitting device and the light receiving device is driven, the organic EL display device may emit light of a predetermined wavelength (for example, green).

FIG. 7 is a perspective view of the collimator 20. In FIG. 7 , a collimator 20 is placed above the light receiving device 10 . The collimator 20 has a structure in which a hole 21 for passing light is formed in a black photosensitive resin 22. Each hole 21 is formed corresponding to the light emitting element 32 of the light emitting device 30 or the light receiving element 11 of the light receiving device 10. However, the present invention can also be applied to a case where a plurality of holes 21 correspond to one light emitting element 32 or one light receiving element 11.

In FIG. 7, the planar shape of the hole 21 in the collimator 20 is a circle. The hole 21 is formed by exposing the photosensitive black resin 22 to light, but this photosensitive resin 22 must be negative. If an attempt is made to form a circular hole in the negative photosensitive resin 22, sufficient patterning precision cannot be obtained. On the other hand, the negative photosensitive resin 22 can be patterned with good precision to have a square planar shape.

Figure 8 is a perspective view of a collimator 20 in which holes 21 with a square planar shape are formed in a photosensitive black resin 22. A collimator 20 such as that shown in Figure 8 can be patterned with high precision when a negative photosensitive resin 22 is used. Figure 9 is a plan view of the collimator 20 shown in Figure 8. Holes 21 are formed in a matrix in the photosensitive black resin 22. In Figure 9, the holes 21 are squares with a side length of a, and currently, for example, a is 10 microns or more due to patterning precision. The horizontal pitch px and vertical pitch py are determined according to the required resolution.

FIG. 10 is a sectional view taken along line AA in FIG. In FIG. 10, the thickness of the collimator 20 is h. The aspect ratio of collimator 20 is defined as h/a. The larger the aspect ratio, the higher the resolution of the optical sensor device. The aspect ratio must be 5 or more, preferably 10 or more, and more preferably 20 or more.

The collimator 20 as shown in FIGS. 9 and 10 has the following two problems. The first problem is that holes with such large aspect ratios are difficult to process. In order to solve this problem, in the present invention, as shown in FIG. 10, the collimator 20 has a laminated structure, and holes 21 are formed in each layer. In FIG. 10, the collimator 20 is formed in two layers, and the aspect ratio of each layer can be h/2a.

The second problem is that, as shown in Figure 9, the diameter of the hole 21 of the collimator 20 in a plane varies depending on the azimuth angle. That is, the aspect ratio of the collimator is h/a in the x direction, whereas the aspect ratio is h/a√2 in a direction at 45 degrees to the x direction. In other words, the aspect ratio varies depending on the direction, which deteriorates the measurement accuracy.

FIGS. 11-13 illustrate this problem graphically. In FIG. 11, a square hole 21 is formed in the collimator 20. FIG. 12 is a cross section taken along line BB in FIG. The take-in angle of the collimator in FIG. 11 is θ1. FIG. 13 is a cross section taken along line CC in FIG. The take-in angle of the collimator in FIG. 13 is θ2. θ2 is larger than θ1.

Therefore, in the first embodiment, the holes 21, which have a square planar shape, are shifted by 45 degrees in each layer when viewed in plan. This significantly reduces the difference in aspect ratio due to the azimuth angle direction. Figure 14 is a plan view of the collimator 20 in this embodiment, and Figures 15 to 17 are cross-sectional views. In Figure 14, the holes 21 formed in the lower layer have sides in the x direction, and the holes 21 formed in the upper layer have diagonal axes in the x direction.

FIG. 15 is a sectional view taken along line DD in FIG. 14. In FIG. 15, the diameter of the hole 21 is larger in the upper layer, and the intake angle is θ3. θ3 is smaller than θ2 in FIG.

FIG. 16 is a sectional view taken along line EE in FIG. In FIG. 16, the diameter of the hole 21 is smaller in the upper layer, but the intake angle is θ3, which is the same as in FIG. 15.

FIG. 17 is a sectional view taken along line FF in FIG. 14, and the intake angle is θ4. 17 shows the angle at which the intake angle is the smallest in the configuration of FIG. 14, but θ4 is larger than θ1 in FIG. 12.

Here, the important point is the difference between the take-in angles rather than the absolute value of the take-in angles. In the configurations shown in FIGS. 11 to 13, the difference in intake angle is (θ2-θ1), whereas in the configurations shown in FIGS. 14 to 17, the difference in intake angle is (θ3-θ4), and (θ3-θ1). θ4) is significantly smaller than (θ2−θ1). Therefore, the configurations shown in FIGS. 14 to 17 can provide better collimator characteristics.

The more layers of collimators are added, the larger the aspect ratio can be. However, when compared in terms of intake angle, it is not always the case that the improvement simply occurs. The diagram on the left side of FIG. 18 is a sectional view taken along line DD in FIG. 14 in the case where the collimator 20 is composed of three layers. A layer having the same shape as the upper layer in FIG. 14 is provided at the bottom layer. In this case, the intake angle is θ5. The figure on the right side of FIG. 18 is a cross-sectional view taken along line EE in FIG. 14 in the case where the collimator 20 is composed of three layers. In this case, the intake angle is θ6. θ5 is larger than θ6. That is, when the collimator 20 is configured with two layers, when comparing the intake angle in the x direction and the intake angle in a direction 45 degrees from the x direction in FIG. 14, the case with three layers is worse than the case with two layers. are doing.

FIG. 19 is a cross-sectional view of the collimator 20 composed of four layers. The diagram on the left side of FIG. 19 is a sectional view taken along line DD in FIG. 14 in the case where the collimator 20 is configured with four layers. In this case, the intake angle is θ7. The figure on the right side of FIG. 19 is a cross-sectional view taken along line EE in FIG. 14 in the case where the collimator 20 is composed of four layers. In this case, the intake angle is θ7. In other words, the difference in intake angles has become smaller again.

Therefore, in order to reduce the difference in the intake angle depending on the azimuth angle in the collimator 20, it is preferable to stack an even number of layers. However, even with an odd number of layers, the absolute value of the uptake angle becomes smaller as the number of layers increases. In other words, it can be said that as the absolute value of the uptake angle becomes smaller, the difference also becomes smaller. Therefore, by increasing the number of layers, the aspect ratio of the collimator 20 increases and the performance as a collimator improves, but in order to further improve it, it is desirable to stack an even number of layers if possible. . Further, although FIG. 14 discloses a configuration in which the square holes formed in the layers are shifted by 45 degrees, this is not particularly limited. If the number of layers is m, the square holes in each layer are shifted by 90 degrees. It may be shifted by m degrees.

In the first embodiment, the light-emitting elements 32, the holes of the collimator 20, and the light-receiving elements 11 are aligned in the x and y directions. However, to increase the detection resolution, it may be better to arrange the light-emitting elements 32 or the light-receiving elements 11 in a delta configuration. Figure 20 is a plan view of the light-emitting elements 32 or the light-receiving elements 11 in a delta configuration. When the light-emitting elements 32 or the light-receiving elements 11 are arranged in a delta configuration, close packing is achieved by making each element hexagonal. Even with this arrangement, wiring areas and the like are necessary. In Figure 20, the width required for wiring and the like is represented by d1.

When the light emitting element 32 or the light receiving element 11 is disposed in a delta arrangement, the planar shape of the hole 21 of the collimator 20 is also preferably hexagonal. This is because the tolerance d2 against the case where the center of the hole 21 of the collimator 20 and the center of the light emitting element 32 or the light receiving element 11 deviate from each other can be maintained at the same value in all directions.

Even when the planar shape of the hole 21 of the collimator 20 is hexagonal, the problem of the intake angle due to the azimuth still exists. This is because, as shown in FIG. 20, the diameter b of the hole in the y direction is different from the diameter a in a direction tilted by 30 degrees from the y direction. Note that the aspect ratio of the collimator 20 when the plane of the hole 21 is hexagonal is defined as h/a, where h is the height of the collimator 20.

Figure 21 shows the planar shape of the holes 21 formed in the collimator 20 in Example 2. In Figure 21, the collimator 20 is configured in two layers. However, the hexagonal holes 21 in the upper layer are rotated 30 degrees in the azimuth direction relative to the hexagonal holes 21 in the lower layer.

FIG. 22 is a sectional view taken along line GG in FIG. 21. The intake angle of the collimator 20 in FIG. 22 is θ11. FIG. 23 is a sectional view taken along line HH in FIG. 21. The take-in angle of the collimator 20 in FIG. 23 is θ11, which is the same as in FIG. 22. In other words, as in the case where the holes are rectangular, the difference in the intake angle in the holes 21 of the collimator 20 can be reduced.

The case where the collimator 20 is formed with three or more layers is also the same as the case described with reference to FIGS. 18 and 19 in the first embodiment. The above description has been made regarding the case where the hole 21 has a hexagonal planar shape, but the same applies to the case where the hole 21 has a pentagonal shape, a heptagonal shape or more. In other words, as shown in Examples 1 and 2, when the collimator 20 is formed with a laminated structure and the planar shape of the hole 21 is an n-gon, the hole 21 in the first layer is By rotating the hole 22 in the plane by 360/2n, the difference in aspect ratio of the collimator 20 in the azimuth direction can be reduced. Note that the corners of the n-gon do not need to have a strict shape in which straight lines intersect, and may have rounded corners. By rounding the corners, it may be possible to reduce the difference in the intake angle depending on the angle.

24A to 24D are cross-sectional views showing problems when forming the collimator 20 by stacking them. The collimator 20 is formed by patterning a negative photosensitive black resin 22. FIG. 24A is a cross-sectional view showing a state in which the photosensitive black resin 221 for the first layer is applied onto the light receiving device 10. The following figures will also be described assuming that the collimator 20 is formed on the light receiving device 10. FIG. 24B is a cross-sectional view showing a state in which holes 21 are formed by patterning the photosensitive black resin 221 by exposing it to light using an exposure mask.

FIG. 24C is a cross-sectional view showing a state in which a photosensitive black resin 222 for forming the second layer is applied. In FIG. 24C, the resin 222 constituting the second layer is also filled in the holes 21 of the first layer. When the thickness of the first layer of the collimator 22 is h1 and the thickness of the second layer is h2, the thickness of the photosensitive black resin 222 in the hole 21 is h1+h2. In this case, since the photosensitive black resin 222 of the second layer in the hole portion 21 of the first layer is thick, it cannot be sufficiently removed under the same development conditions, so that a residue 225 exists.

FIGS. 25A and 25B are cross-sectional views showing a first form of countermeasure against this problem. In FIG. 25A, a photosensitive black resin 222 constituting a second layer is applied on a first layer 221 constituting the collimator. The thickness h2 of the second layer 222 is greater than the thickness h1 of the first layer 221. In FIG. 25A, if the difference between the thickness h1+h2 of the second layer of photosensitive black resin 222 in the hole 21 and the thickness h2 of the second layer of photosensitive black resin 222 on the first layer 221 is not large, the same development Under these conditions, it is possible to prevent the residue 225 of the photosensitive black resin 222 of the second layer from remaining in the hole 21 of the first layer 221. This state is shown in FIG. 25B.

Figures 26A to 27B are cross-sectional views showing a second embodiment of Example 3. Figure 26A is a cross-sectional view of a first layer 221 with holes 21 formed therein, and Figure 26B is a cross-sectional view of a second layer with photosensitive black resin 222 formed on the first layer 221. The feature of Figure 26B is that the thickness h2 of the photosensitive black resin 222 constituting the second layer is smaller than the thickness h1 of the first layer 221, so that the holes 21 in the first layer 221 are not filled with the photosensitive black resin 222 of the second layer.

In FIG. 26B, the difference between the thickness h3 of the second layer of photosensitive black resin 222 in the hole 21 and the thickness h2 of the second layer of photosensitive black resin 222 on the first layer 221 can be made small; As shown in FIG. 2, it is possible to prevent the residue 225 of the photosensitive black resin 222 from remaining inside the hole 21.

Figures 27A and 27B show an example in which a process similar to that described in Figures 26A to 26C is applied to the third layer 223 of the collimator 20. A similar process can also be applied to four or more layers.

28A to 28D are cross-sectional views showing a third embodiment of the third embodiment. FIG. 28A is a cross-sectional view showing a state in which photosensitive black resin 222 for forming a second layer is applied onto the first layer 221. In this case, the photosensitive black resin 222 of the second layer is selected to be a material that does not penetrate into the holes 21 of the first layer 221 in relation to the diameter of the holes 21 of the first layer 221, the viscosity of the photosensitive black resin 222 of the second layer, and the wettability of the material of the photosensitive black resin 222 of the second layer with the surface of the light receiving element 10.

FIG. 28B is a cross-sectional view showing a state in which the shape of the second layer 222 is formed by performing exposure and development. As shown in FIG. 28B, it is possible to prevent residues 225 of the second layer material 222 from remaining within the hole 21.

28C and 28D are processes for constructing the third layer 223 of the collimator. In terms of process, FIG. 28C corresponds to FIG. 28A, and FIG. 28D corresponds to FIG. 28B. In this way, even when the collimator 20 is formed with three or more layers, it is possible to prevent the photosensitive black resin residue 225 from remaining in the hole 21 by the process described in FIGS. 28A and 28B.

Example 4 provides another configuration when the collimator 20 is formed by stacking. Fig. 29A is a cross-sectional view of a state in which only air exists in the hole 21 of the collimator 20. In Fig. 29A, the collimator 20 is placed on the light receiving device 10, and the substrate 200 of the light emitting device 30 is placed on the collimator 20.

In FIG. 29A, light incident from the substrate 200 is refracted at the interface between the substrate 200 and air. Since the refractive index n0 of air is smaller than the refractive index n2 of the substrate 200, θ1<θ2. The significantly refracted light is absorbed by the black resin 22 and does not reach the light receiving device 10. Therefore, light incident at an incident angle greater than θ1 does not reach the light receiving device 10. In other words, the configuration of FIG. 29A allows more collimated light to enter the light receiving device 10 due to the effect of the difference in refractive index.

FIG. 29B is a cross-sectional view showing a state in which the hole 21, which is the light guiding portion of the first layer 221 of the collimator 20, is filled with a transparent resin 25 having a refractive index of n1. Only air exists in the holes 21 of the second layer 222 of the collimator 20. In FIG. 29, light that enters the second layer 222 of the collimator 20 from the substrate 200 at an incident angle θ3 is refracted and travels at an angle θ4, is refracted again at the interface between the first layer and the second layer of the collimator, and then enters the second layer 222 of the collimator 20. Proceeds at an angle θ5. This light is absorbed by the black resin 221 of the collimator 20 and does not reach the light receiving device 10. Therefore, light incident at an incident angle greater than θ3 does not reach the light receiving device 10. In other words, the configuration of FIG. 29A allows more collimated light to enter the light receiving device due to the effect of the difference in refractive index.

If the refractive index n1 of the transparent resin 25 is smaller than the refractive index n2 of the second substrate 200, sufficient effects can be achieved even when the holes 21 of the first layer 221 are filled with the transparent resin 25. In other words, the smaller the refractive index n1 of the transparent resin 25, the more effective the effect can be.

30A to 30D are cross-sectional views showing a configuration for not leaving residue 225 of the photosensitive black resin 222 in the hole 21 of the collimator 20 when the collimator 20 is formed by laminating. FIG. 30A is a cross-sectional view showing a state in which the transparent resin 25 is applied to cover the first layer 221 of the collimator 20. The transparent resin 25 is also filled in the holes 21 of the first layer 221. The transparent resin 25 is made of photosensitive resin.

Figure 30B is a cross-sectional view showing the state in which the transparent resin 25 has been exposed and developed, and the transparent resin 25 has been removed from all parts of the first layer 221 except for the inside of the holes 21. Figure 30C is a cross-sectional view showing the state in which the photosensitive black resin 222 for forming the second layer has been applied onto the first layer 221. Figure 30D is a cross-sectional view showing the state in which the photosensitive black resin 222 of the second layer has been exposed and developed to form the second layer 222 of the collimator 20.

As shown in FIG. 30C, the photosensitive black resin 222 forming the second layer has a uniform thickness, so that no residue 225 of the photosensitive black resin 222 is present in the hole 21, as shown in FIG. 30D.

31A to 31C are cross-sectional views showing a second form of Example 4. FIG. In the second embodiment as well, the transparent resin 25 is first formed on the first layer 221 of the collimator, as shown in FIG. 30A. When exposing and developing the image shown in FIG. 30A, it is difficult to control the transparent resin 25 to have the same thickness as the first layer of photosensitive black resin 221.

Figure 31A is a cross-sectional view showing a state in which a thin layer of transparent resin 25 remains on the first layer of photosensitive black resin 221. A configuration like that shown in Figure 31A can be formed stably because it requires slightly less exposure. Figure 31B is a cross-sectional view showing a state in which a second layer of photosensitive black resin 222 has been applied on top of the transparent resin 25.

FIG. 31C is a cross-sectional view showing a state in which the photosensitive black resin 222 is developed to form a second layer. Since the photosensitive black resin 222 constituting the second layer has a uniform thickness, there is no residue 225 of the photosensitive black resin 222 in the hole 21 . In the collimator 20, a thin film of transparent resin 25 exists between the first layer 221 and the second layer 222, but there is almost no problem in terms of the characteristics of the collimator 20.

32A to 32C are cross-sectional views showing a third form of Example 4. FIG. In the third embodiment, the transparent resin 25 is first formed on the first layer 221 of the collimator, as shown in FIG. 30A.

In FIG. 32A, contrary to FIG. 31A, the thickness of the transparent resin 25 in the hole 21 of the first layer 221 of the collimator is made greater than the thickness of the black resin 221 of the first layer by exposing the transparent resin 25 to a slightly stronger light. FIG.

Figure 32B is a cross-sectional view showing the state in which the photosensitive black resin 222 constituting the second layer is applied on the view of Figure 32A. In Figure 32B, the thickness of the second layer of photosensitive black resin 222 is thicker on the transparent resin 25 than on the first layer of photosensitive black resin 221, but the difference is small, so that no residue 225 of the photosensitive black resin 222 remains in the hole 21 when the second layer 222 is developed, as shown in Figure 32C.

DESCRIPTION OF SYMBOLS 10... Light receiving device, 11... Light receiving element, 12... Light receiving element protective film, 15... Photoconductive element, 16... TFT, 17... Storage capacitor, 20... Collimator, 21... Hole (light guide part), 22... Black resin, 25... Transparent resin, 30... Light emitting device, 32... Light emitting element, 33... Light emitting element protective film, 34... Protective substrate, 40... Measured object, 51... Scanning line, 52... Detection line, 53... Power line, 55... Scanning circuit, 56...Detection line drive circuit, 57...Power supply circuit, 60...Light emitting region, 61...Scanning line, 62...Signal line, 63...Power supply line, 65...Scanning circuit, 66...Signal line drive circuit, 67...Power supply Circuit, 100... First substrate, 101... Base film, 102... Light shielding film, 103... Lower gate insulating film, 104... Semiconductor film, 105... Drain electrode, 106... Source electrode, 107... Gate insulating film, 108... Upper gate Electrode, 109... Capacitance electrode, 110... Interlayer insulating film, 111... Drain wiring, 112... Contact electrode, 113... Organic passivation film, 114... Cathode, 115... Photoconductive film, 116... Anode, 117... Second interlayer insulating film , 118... Anode wiring, 119... Inorganic protective film, 120... Organic protective film, 121... Through hole, 122... Through hole, 123... Through hole, 140... Bank, 150... Anode, 151... Organic EL layer, 152... Cathode , 153... Protective film, 200... Second substrate, 221... First photosensitive black resin, 222... Second photosensitive black resin, 223... Third photosensitive black resin, 225... Residue of photosensitive black resin, 400... Opening, 1151...p layer, 1152...i layer, 1153...n layer, EL...organic EL light emitting layer, T1...switching TFT, T2...driving TFT, Ch...retention capacitor, Va...anode voltage, Vk...cathode voltage

Claims (18)

An optical sensor device having a light receiving device, a collimator, and a light emitting device,
The collimator is arranged between the light receiving device and the light emitting device,
The collimator has a structure in which multiple layers including a first collimator and a second collimator are laminated,
The first collimator and the second collimator have a structure in which a hole through which light passes is formed in a light-shielding resin,
When n is an integer of 4 or more, the first hole formed in the first collimator has an n-gon shape when viewed in plan, and the second hole formed in the second collimator has an n-gon shape when viewed in plan. 1. An optical sensor device characterized in that the center thereof is the same as that of the first hole, and the center thereof is rotated by 360 degrees/2n with respect to the first hole. 2. The optical sensor device according to claim 1, wherein the light-shielding resin is made of a negative photosensitive black resin. The optical sensor device according to claim 1, characterized in that the n-sided shape is a quadrilateral. The optical sensor device according to claim 1, wherein the n-gon is a hexagon. The optical sensor device according to claim 1, characterized in that the thickness of the first collimator is greater than the thickness of the second collimator. The optical sensor device according to claim 1, characterized in that the thickness of the first collimator is thinner than the thickness of the second collimator. The optical sensor device according to claim 1, characterized in that the aspect ratio of the collimator is 5 or more. The optical sensor device according to claim 1, characterized in that the aspect ratio of the collimator is 10 or more. The optical sensor device according to claim 1, wherein the light receiving device, the collimator, and the light emitting device are integrally formed by stacking them in this order. The optical sensor device according to claim 1, characterized in that the light receiving device, the collimator, and the light emitting device are continuously formed by stacking them in this order. The optical sensor device according to claim 1, characterized in that the light receiving device is randomly accessible. The optical sensor device according to claim 1, wherein the light emitting device is randomly accessible. An optical sensor device having a collimator,
The collimator has a structure in which multiple layers including a first collimator and a second collimator are laminated,
The first collimator has a structure in which a transparent resin is formed in a first hole that allows light to pass through a light-blocking resin, and the second collimator has a second hole that allows light to pass through a light-blocking resin. is formed,
When n is an integer of 4 or more, the first hole formed in the first collimator has an n-gon shape when viewed in plan, and the second hole formed in the second collimator has an n-gon shape when viewed in plan . An optical sensor device characterized in that the center thereof is the same as that of the first hole, and the center thereof is rotated by 360 degrees/2n with respect to the first hole. The optical sensor device according to claim 13, characterized in that the transparent resin is present between the first collimator and the second collimator and has a thickness thinner than the first collimator and the second collimator. The optical sensor device according to claim 13, characterized in that the thickness of the transparent resin in the first hole is smaller than the thickness of the first collimator. a substrate constituting a light receiving device is disposed on the second collimator;
14. The optical sensor device according to claim 13, wherein the refractive index of the substrate is greater than the refractive index of the transparent resin. An optical sensor device having a light receiving device, a collimator, and a light emitting device,
The collimator is arranged between the light receiving device and the light emitting device,
The substrate of the light emitting device is made of transparent resin,
The collimator faces the substrate of the light emitting device,
The collimator has a structure in which multiple layers including a first collimator and a second collimator are laminated,
The first collimator and the second collimator have a structure in which a hole through which light passes is formed in a light-shielding resin,
When n is an integer of 4 or more, the first hole formed in the first collimator has an n-gon shape when viewed in plan, and the second hole formed in the second collimator has an n-gon shape when viewed in plan. It has the same center as the first hole and is rotated 360 degrees/2n with respect to the first hole,
The optical sensor device according to claim 1, wherein a transparent resin made of the same material as the substrate of the light emitting device is present in the second hole. 18. The optical sensor device according to claim 17, wherein a transparent resin made of the same material as the substrate of the light emitting device is present in the first hole.

Images