Patent Description:
<CIT> discloses a light sensing module comprising: a substrate; a light sensing unit being disposed on the substrate to sense an intensity of a working light beam; a first light-transmissive component covering the light sensing unit, wherein the first light-transmissive component has multiple refractive index layers, with the refractive index decreasing from lower layers to upper layers, between a refractive index of the light sensing unit and a refractive index of air; and a blocking wall being disposed on the substrate and surrounding the light sensing unit and the first light-transmissive component.

Further light sensing modules are known from <CIT>, <CIT>, and <CIT>.

With the emphasis on public health awareness, leisure sports have become more and more popular. This has contributed to acceleration in the development and popularization of wearable devices. Compared to mobile phones, the wearable devices have the advantages of being compact and lightweight, and are therefore suitable for use when exercising or being on the move. In addition to having the functions of displaying time and providing notifications, the wearable devices can also monitor instant physiological signals such as pulse signals in real time, such that consumers can be made aware of their own physiological states at all times.

A common way of monitoring physiological signals is through a light sensor, although many inadequacies are still associated therewith in actual use. In the use of the conventional wearable devices, the quality of monitored physiological signals may be negatively affected by a user's skin color, a brightness of the environment, a proper or improper fit of wearing the device, and a user's exercise state. That is, the interference (crosstalk) resulted from such factors may affect the interpretation of weak physiological signals that are measured, and even completely cover over the measured weak physiological signals. For example, when a user is exercising vigorously in an outdoor environment, the monitoring performance of a light sensor of physiological signals would be negatively affected by the strong sunlight. In addition, a large range of motion or a vigorous degree of exercise can easily affect the fit between a wearable device and a human body, thus affecting the calculation of physiological values. If a user changes his/her exercise intensity according to an inaccurate physiological value, he/she may suffer serious injury. On the other hand, since the wearable devices are generally designed to be multifunctional, lightweight, and handy, there are inevitable restrictions in size and location of a space required for arranging the light sensor. This may cause a light receiving area of the light sensor to be limited in range, thus affecting the calculation of the physiological values. As a result, it can be difficult to perform a complete assessment of a physiological state.

Therefore, in order to allow a user to accurately read his/her physiological values in indoor and outdoor environments and in various exercise conditions, it is an important and urgent issue in modern society to develop a light sensing device that can effectively reduce optical interference and increase monitoring sensitivity.

In response to the above-referenced technical inadequacies, the present disclosure provides a light sensing module having good sensitivity and accuracy, and an electronic device using the same.

The light sensing module of the invention is defined in the appended claims.

In one embodiment of the present disclosure, the blocking wall has a light transmittance of less than <NUM> % with respect to the working light beam.

In one embodiment of the present disclosure, the blocking wall has a thickness between <NUM> and <NUM>.

In one embodiment of the present disclosure, the first light-transmissive component has a thickness between <NUM> and <NUM>. The second light-transmissive component has a thickness between <NUM> and <NUM>.

In one embodiment of the present disclosure, the first refractive index of the first light-transmissive component is between <NUM> and <NUM>. The second refractive index of the second light-transmissive component is between <NUM> and <NUM>.

In one embodiment of the present disclosure, the light sensing unit has an upper light receiving surface and a lateral surface perpendicular to the upper light receiving surface. The lateral surface and the blocking wall has a gap therebetween that is filled with the light shielding layer.

In one embodiment of the present disclosure, the light shielding layer has a light transmittance of less than <NUM> % with respect to the working light beam.

In one embodiment of the present disclosure, the light sensing module further includes a third light-transmissive component, which surrounds the first light-transmissive component and has a third refractive index. The third refractive index is less than the first refractive index.

In one embodiment of the present disclosure, the third light-transmissive component has a thickness between <NUM> and <NUM>.

In one embodiment of the present disclosure, the third refractive index of the third light-transmissive component is between <NUM> and <NUM>.

In one embodiment of the present disclosure, the third light-transmissive component contains light diffusing particles.

In one embodiment of the present disclosure, the light diffusing particles have an average particle diameter between <NUM> and <NUM>. The light diffusing particles are present in an amount between <NUM> wt % and <NUM> wt % based on <NUM> wt % of the third light-transmissive component.

In one embodiment of the present disclosure, the light sensing unit has a first electrode at a bottom portion thereof and a second electrode at a top portion thereof. The substrate has a first contact pad and a second contact pad that are separate from each other. The first electrode is bonded to the first contact pad and the second electrode is electrically connected to the second contact pad via a wire.

In another aspect, the present disclosure provides an electronic device, which includes a light emitting module and a light sensing module having the structure as described above. The light emitting module is configured to emit a working light beam. The light sensing module is configured to sense an intensity of the working light beam.

Therefore, the light sensing module of the present disclosure, in which the first light-transmissive component covers the light sensing unit and has a first refractive index that is between a refractive index of the light sensing unit and a refractive index of air, and the blocking wall is disposed on the substrate and surrounds the light sensing unit and the first light-transmissive component, has the following beneficial effects. The sensing range can be expanded, the blind spot can be reduced, and the crosstalk of external lights on the light sensing unit can be reduced.

The present disclosure will become more fully understood from the following detailed description and accompanying drawings.

Referring to <FIG>, an example not being part of the present invention provides a light sensing module Z1, which includes a substrate <NUM>, a light sensing unit <NUM>, a first light-transmissive component 3a and a blocking wall <NUM>. The light sensing unit <NUM> is disposed on the substrate <NUM>. The first light-transmissive component 3a covers the light sensing unit <NUM>. The blocking wall <NUM> is disposed on the substrate <NUM> and surrounds the light sensing unit <NUM> and the first light-transmissive component 3a.

In the present example, the light sensing unit <NUM> can be arranged in an electronic device (e.g., a wearable electronic device) through the substrate <NUM> to sense an intensity of a working light beam. Accordingly, the electronic device can perform a desired action according to a sensing result, such as measuring a physiological signal of a user. Furthermore, the first light-transmissive component 3a has a first refractive index that is between a refractive index of the light sensing unit <NUM> and a refractive index of air, so as to realize a refractive index matching function. Therefore, a sensing range of the light sensing unit <NUM> can be expanded, and a blind spot of the light sensing unit <NUM> can be reduced. The blocking wall <NUM> has low light transmittance so as to reduce the crosstalk of external lights on the light sensing unit <NUM>. Therefore, the sensitivity and accuracy of the light sensing unit <NUM> can be significantly improved. As used herein, the term "refractive index of light sensing unit <NUM>" refers to a matching refractive index of a portion of the light sensing unit <NUM> that is in contact with the first light-transmissive component 3a.

In practice, the substrate <NUM> can be a circuit board with a plurality of inner connecting interfaces and a plurality of outer connecting interfaces. The light sensing unit <NUM> can be a photodetector chip and can work with a light emitting unit (not shown). The light emitting unit is configured to emit a working light beam such as a visible or invisible light beam. The light sensing unit <NUM> is configured to receive the working light beam, and to generate a current corresponding to the intensity of the working light beam. The first light-transmissive component 3a can be a layered structure that is formed of, for example, a silicone-based resin. Furthermore, the refractive index (i.e., the first refractive index) of the first light-transmissive component 3a can be between <NUM> and <NUM>, and is preferably <NUM>. The thickness of the first light-transmissive component 3a can be between <NUM> and <NUM>. The blocking wall <NUM> can be formed of a resin composition including a silicone-based resin and a black carbon powder (K Black). The blocking wall <NUM> can be fixed on the substrate <NUM> by an adhesive layer (not shown). In the present embodiment, a bottom portion of the blocking wall <NUM> extends into the substrate <NUM> so as to realize a better light blocking effect. The above-described details are merely exemplary, and are not intended to limit the present disclosure. In an example that is not shown, the blocking wall <NUM> can be integrated on a surface of the substrate <NUM>.

More specifically, the inner connecting interfaces of the substrate <NUM> include a first contact pad <NUM> and a second contact pad <NUM> which are separated from each other. The light sensing unit <NUM> can be electrically connected to the first contact pad <NUM> and the second contact pad <NUM> by any suitable means, which depends on the form of the light sensing unit <NUM>. For example, the light sensing unit <NUM> has a first electrode <NUM> at a bottom portion thereof and a second electrode <NUM> at a top portion thereof, as shown in <FIG>. The light sensing unit <NUM> can be bonded to the first contact pad <NUM> of the substrate <NUM> by a die attach adhesive or soldering material, in which the first electrode <NUM> is electrically connected to the first contact pad <NUM>, and the second electrode <NUM> can be electrically connected to the second contact pad <NUM> by a wire W. In consideration of costs and product reliability, the blocking wall <NUM> has a light transmittance to the working light beam of preferably less than <NUM> %, and has a thickness of preferably between <NUM> and <NUM>.

Referring to <FIG>, a second example not being part of the present invention provides a light sensing module Z2, which includes a substrate <NUM>, a light sensing unit <NUM>, a first light-transmissive component 3a, a second light-transmissive component 3b and a blocking wall <NUM>. The light sensing unit <NUM> is disposed on the substrate <NUM>. The first light-transmissive component 3a covers the light sensing unit <NUM>. The second light-transmissive component 3b is disposed between the light sensing unit <NUM> and the first light-transmissive component 3a. The blocking wall <NUM> is disposed on the substrate <NUM>, and surrounds the light sensing unit <NUM>, the first light-transmissive component 3a and the second light-transmissive component 3b. The technical details of the substrate <NUM>, the light sensing unit <NUM>, the first light-transmissive component 3a and the blocking wall <NUM> have been described in the first example, and will not be reiterated herein.

In the present example, the first light-transmissive component 3a has a first refractive index that is between a refractive index of the light sensing unit <NUM> and a refractive index of air. The second light-transmissive component 3b has a second refractive index that is between the refractive index of the light sensing unit <NUM> and the first refractive index. Therefore, the first light-transmissive component 3a and the second light-transmissive component 3b can jointly realize a refractive index matching function to further increase the sensitivity of the light sensing unit <NUM>. In practice, the second light-transmissive component 3b can be formed of a silicone-based resin. Furthermore, the refractive index (i.e., the second refractive index) of the second light-transmissive component 3b can be between <NUM> and <NUM>, and is preferably <NUM>. The thickness of the second light-transmissive component 3b can be between <NUM> and <NUM>. More specifically, the light sensing unit <NUM> has an upper light receiving surface <NUM> and a lateral surface <NUM> perpendicular to the upper light receiving surface <NUM>. The second light-transmissive component 3b is a film that is shaped in advance and then attached to the upper light receiving surface <NUM> of the light sensing unit <NUM>. Also, the second light-transmissive component 3b can be formed on the upper light receiving surface <NUM> of the light sensing unit <NUM> by coating and curing. The above-described details are merely exemplary, and are not intended to limit the present disclosure.

Referring to <FIG>, an embodiment of the present invention provides a light sensing module Z3, which includes a substrate <NUM>, a light sensing unit <NUM>, a first light-transmissive component 3a, a second light-transmissive component 3b, a blocking wall <NUM> and a light shielding layer <NUM>. The light sensing unit <NUM> is disposed on the substrate <NUM>. The light shielding layer <NUM> is disposed on the substrate <NUM> and surrounds the light sensing unit <NUM>. The first light-transmissive component 3a covers the light sensing unit <NUM> and the light shielding layer <NUM>. The second light-transmissive component 3b is disposed between the light sensing unit <NUM> and the first light-transmissive component 3a. The blocking wall <NUM> is disposed on the substrate <NUM>, and surrounds the light sensing unit <NUM>, the first light-transmissive component 3a, the second light-transmissive component 3b and the light shielding layer <NUM>. The technical details of the substrate <NUM>, the light sensing unit <NUM>, the first light-transmissive component 3a, the second light-transmissive component 3b and the blocking wall <NUM> have been described in the aforesaid examples, and will not be reiterated herein.

In the present embodiment, the light shielding layer <NUM> is disposed between the light sensing unit <NUM> and the blocking wall <NUM>. The light shielding layer <NUM> also has low light transmittance and can work with the blocking wall <NUM> to jointly realize an external light shielding function. Therefore, in the presence of the light shielding layer <NUM>, the crosstalk of external lights on the light sensing unit <NUM> can be decreased. As a result, the light sensing unit <NUM> has a higher accuracy and can thus greatly reduce misjudgment rate. In practice, a lateral surface <NUM> of the light sensing unit <NUM> and the blocking wall <NUM> has a gap G therebetween, which can be completely or partially filled with the light shielding layer <NUM>. Preferably, the gap G is completely filled with the light shielding layer <NUM>. The light shielding layer <NUM> can be formed of, for example, a resin composition including a silicone-based resin and a black carbon powder (K Black). The above-described details are merely exemplary, and are not intended to limit the present disclosure.

Referring to <FIG>, another embodiment of the present disclosure provides a light sensing module Z4, which includes a substrate <NUM>, a light sensing unit <NUM>, a first light-transmissive component 3a, a second light-transmissive component 3b, a third light-transmissive component 3c, a blocking wall <NUM> and a light shielding layer <NUM>. The light sensing unit <NUM> is disposed on the substrate <NUM>. The light shielding layer <NUM> is disposed on the substrate <NUM> and surrounds the light sensing unit <NUM>. The first light-transmissive component 3a covers the light sensing unit <NUM>. The second light-transmissive component 3b is disposed between the light sensing unit <NUM> and the first light-transmissive component 3a. The third light-transmissive component 3c surrounds the first light-transmissive component 3a, and corresponds in position to the light shielding layer <NUM>. The blocking wall <NUM> is disposed on the substrate <NUM>, and surrounds the light sensing unit <NUM>, the first light-transmissive component 3a, the second light-transmissive component 3b, the third light-transmissive component 3c and the light shielding layer <NUM>. The technical details of the substrate <NUM>, the light sensing unit <NUM>, the first light-transmissive component 3a, the second light-transmissive component 3b, the blocking wall <NUM> and the light shielding layer <NUM> have been described in the aforesaid embodiments, and will not be reiterated herein.

In the present embodiment, the first light-transmissive component 3a has a first refractive index that is between a refractive index of the light sensing unit <NUM> and a refractive index of air. The second light-transmissive component 3b has a second refractive index that is between the refractive index of the light sensing unit <NUM> and the first refractive index. The third light-transmissive component 3c has a third refractive index that is less than the first refractive index. Therefore, the first light-transmissive component 3a and the third light-transmissive component 3c can jointly realize a refractive index matching function to further increase the sensitivity of the light sensing unit <NUM>, the related details of which are described below. In practice, the third light-transmissive component 3c can be a layered structure that is formed of, for example, a silicone-based resin. Furthermore, the refractive index (i.e., the third refractive index) of the third light-transmissive component 3c can be between <NUM> and <NUM>, and preferably <NUM>. The thickness of the third light-transmissive component 3c can be between <NUM> and <NUM>. The above-described details are merely exemplary, and are not intended to limit the present disclosure.

Reference is now made to <FIG>. In use of the structure as described in the present embodiment, in which the refractive index of the third light-transmissive component 3c is less than the refractive index of the first light-transmissive component 3a, although a portion of a working light beam L1 is radiated to the third light-transmissive component 3c rather than directly entering a sensing range of the light sensing unit <NUM>, the working light beam L1 can undergo a total reflection at a boundary between the first light-transmissive component 3a and the third light-transmissive component 3c, so as to be received by the upper light receiving surface <NUM> or the lateral surface <NUM> of the light sensing unit <NUM>. That is, the sensing range of the light sensing unit <NUM> can be increased by the refractive index matching function that is jointly realized by the first light-transmissive component 3a and the third light-transmissive component 3c.

Referring to <FIG> and <FIG>, which is to be read in conjunction with <FIG>, another embodiment of the present invention provides a light sensing module Z5 having a structure that is the same as the structure of the light sensing module Z4 of the embodiment of <FIG>.

The main difference with the previous embodiment is that the third light-transmissive component 3c contains light diffusing particles P.

In the present embodiment, the light diffusing particles P can result in a scattering effect of a working light beam L2, and a resulting scattered light beam L21 is able to be received by the upper light receiving surface <NUM> or the lateral surface <NUM> of the light sensing unit <NUM>, as shown in <FIG>. As a result, the sensing range of the light sensing unit <NUM> can also be increased, thereby increasing sensing sensitivity. In practice, the light diffusing particles P can be inorganic particles, and preferably titanium dioxide particles. In consideration of processability and sensing efficiency, the light diffusing particles P have an average particle diameter between <NUM> and <NUM>, and are present in an amount between <NUM> wt % and <NUM> wt % based on <NUM> wt % of the third light-transmissive component 3c. The above-described details are merely exemplary, and are not intended to limit the present disclosure. For example, the first light-transmissive component 3a can also contain light diffusing particles depending on particular implementations.

Referring to <FIG>, the light sensing module Z5 of this embodiment can be manufactured by the following steps. Firstly, a substrate <NUM> is provided, having a first contact pad <NUM> and a second contact pad <NUM> that is separate from the first contact pad <NUM>, and a blocking wall <NUM> that is formed on the substrate <NUM>. Next, a light sensing unit <NUM> is attached to the first contact pad <NUM> of the substrate <NUM>, and a wire W is used to connect the light sensing unit <NUM> to the second contact pad <NUM> of the substrate <NUM>. Next, a first light-transmissive component 3a and a second light-transmissive component 3b are formed on the light sensing unit <NUM>, in which the second light-transmissive component 3b is formed between the light sensing unit <NUM> and the first light-transmissive component 3a. Then, a light shielding layer <NUM> is formed between the light sensing unit <NUM> and the blocking wall <NUM>. Lastly, a third light-transmissive component 3c with light diffusing particles P is formed on the light shielding layer <NUM> to surround the first light-transmissive component 3a. The technical details of each step have been described in the aforesaid embodiments, and will not be reiterated herein.

Referring to <FIG>, the present disclosure further provides an electronic device D, which includes a light emitting module E and a light sensing module Z1, Z2, Z3, Z4, Z5 having the structure as described above. The light emitting module E is configured to emit a working light beam L3. The light sensing module Z1, Z2, Z3, Z4, Z5 is configured to sense an intensity of the working light beam. More specifically, the electronic device D of the present disclosure can serve as a wearable electronic device. When the working light beam L3 emitted from the light emitting module E is projected onto an object Z such as a part of a user's body, a reflected light beam L31 is formed and enters into the light sensing module Z1, Z2, Z3, Z4, Z5 to be received by the light sensing unit <NUM>. Accordingly, the electronic device D can determine whether or not to start measuring a user's physiological signal according to the magnitude of a current generated by the light sensing unit <NUM>.

In conclusion, the light sensing module of the present disclosure, in which the first light-transmissive component covers the light sensing unit and has a first refractive index that is between a refractive index of the light sensing unit and a refractive index of air, and the blocking wall is disposed on the substrate and surrounds the light sensing unit and the first light-transmissive component, has the following beneficial effects. The sensing range can be expanded, the blind spot can be reduced, and the crosstalk of external lights on the light sensing unit can be reduced.

Furthermore, the first light-transmissive component, the combination of the first light-transmissive component and the second light-transmissive component, or the combination of the first light-transmissive component, the second light-transmissive component and the third light-transmissive component can realize a refractive index matching function individually or jointly to further increase the sensitivity of the light sensing unit.

In addition, the light shielding layer can work with the blocking wall to jointly realize an external light shielding function. Therefore, the crosstalk of external lights on the light sensing unit can be decreased to greatly reduce misjudgment rate.

The above beneficial effects can be verified from the performance test results as shown in Table <NUM>:.

Claim 1:
A light sensing module (Z3, Z4, Z5), comprising:
a substrate (<NUM>);
a light sensing unit (<NUM>) being disposed on the substrate (<NUM>) to sense an intensity of a working light beam;
a first light-transmissive component (3a) covering the light sensing unit (<NUM>), wherein the first light-transmissive component (3a) has a first refractive index that is between a refractive index of the light sensing unit (<NUM>) and a refractive index of air; and
a blocking wall (<NUM>) being disposed on the substrate (<NUM>) and surrounding the light sensing unit (<NUM>) and the first light-transmissive component (3a);
a second light-transmissive component (3b) being disposed between the light sensing unit (<NUM>) and the first light-transmissive component (3a), and having a second refractive index between the refractive index of the light sensing unit (<NUM>) and the first refractive index; the light sensing module (Z3, Z4, Z5) being characterized by further comprising
a light shielding layer (<NUM>) being disposed between the light sensing unit (<NUM>) and the blocking wall (<NUM>).