TWI582452B - Adjustment method and proximity sensor - Google Patents

Description

Adjustment method and its proximity sensor

The invention relates to an adjustment method and a proximity sensor, in particular to an adjustment method for automatically adjusting the proximity sensor parameters and a proximity sensor through a progressive test.

With the evolution of sensing technology, more and more electronic devices are equipped with sensors to achieve more functions. For example, handheld devices such as smart phones and tablets are equipped with Proximity Sensors. When the user wants to answer the call, the proximity sensor automatically detects the object close to the mobile phone, and the screen then turns off the display and touch. Control function. In this way, the smart phone not only saves the power consumption of the display panel, prolongs the battery life, but also avoids unnecessary misuse. When the phone opens the user's ear to a certain distance, the screen will light up again and the touch function will start again. For example, an LCD TV, a computer screen, or an All in One (AIO) computer equipped with a Long Distance Proximity Sensor is used to detect absenteeism, gestures, or body manipulation, such as contactless Automatic switch, active speaker volume adjustment, keyboard backlight control and other applications. Once the user opens the machine, the screen will automatically turn off, save power, and re-approach the machine and the screen will turn back on.

However, as the application surface of the sensor becomes more and more extensive, there are still many non-ideal effects of proximity sensors, such as the surface characteristics of the object to be tested and the mechanism of proximity to the sensor when the sensor is detected. Shape will affect the accuracy of the sensing. For example, when the proximity sensor is to detect a long distance, it is necessary to increase the driving capability of the light-emitting element or increase the setting of the gain of the capture circuit, which increases the complexity and power consumption of the sensor circuit.

Therefore, how to enable system manufacturers to quickly adjust the proximity sensor parameters, so that system manufacturers can take into account the application of short-range and long-distance ,, and overcome the variation caused by non-ideal test objects, has become a proximity sensor manufacturer The main topic.

Accordingly, it is a primary object of the present invention to provide an adjustment method and associated proximity sensor.

The invention discloses an adjustment method for adjusting a gain of a proximity sensor and a transmission period according to a distance of a sample to be tested. The distance of the object to be tested is the distance between the proximity sensor and an object to be tested. The adjusting method includes: a first step of: emitting a light toward the object to be tested according to the emission period; and a second step of receiving the reflected light to reflect light from the object to be tested; a third step of converting the reflected light into a first analog signal; a fourth step of selecting an index M from the plurality of indices according to a search method; a fifth step to set the gain to be 2 ^M ; a sixth step of: amplifying the first analog signal as a second analog signal according to the gain; and a seventh step of converting the second analog signal to a digital value; wherein the first step to the seventh The steps are performed repeatedly until the digital value corresponds to the distance of the object to be tested.

The invention further discloses a proximity sensor. The proximity sensor is a distance from a test object to a test object. The proximity sensor includes a light emitter for emitting a light toward the object to be tested according to a period of emission, and a light sensor for receiving the light reflected from the object to be detected. And converting the reflected light into a first analog signal; a reading circuit for selecting an index M from the plurality of indices according to a search method, setting a gain to 2 ^M and amplifying the first according to the gain The analog signal is a second analog signal; an analog digital converter is used to convert the second analog signal into a digital value; and a logic control unit is configured to interpret whether the digital value corresponds to the distance of the object to be tested. The logic control unit is further configured to control the light emitter, the light sensor, the read circuit, and the analog digital converter to repeatedly perform their functions until the digital value corresponds to the object distance.

According to the above embodiment, the invention can quickly adjust the parameters of the proximity sensor according to different application environments through the progressive programmable detection process, which can greatly reduce the manufacturer's production process.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of a Proximity Sensor 10 according to an embodiment of the present invention. The proximity sensor 10 is configured to detect whether an object to be tested 100 exists outside the DST, and includes a light emitter 102, a light sensor 104, a read circuit 106, and an analog-to-digital conversion. Analog-to-Digital Converter (ADC) 108 and a logic control unit 110. The light emitter 102 is configured to emit an emitted light Ltx toward the object to be tested 100 according to a firing period. The object to be tested 100 reflects the emitted light Ltx and generates a reflected light Lrf (the process penetrates the half of the transparent member 120). The photo sensor 104 is configured to receive the reflected light Lrf and convert the reflected light Lrf into a first analog signal A1. The read circuit 106 is configured to select an index M from a plurality of indices M1, M2, ... MN according to a search method, and then set a gain of 2 ^M . The read circuit 106 then amplifies the first analog signal A1 to a second analog signal A2 according to the gain 2 ^M . The analog to digital converter 108 is used to convert the second analog signal A2 to a digital value DV. The logic control unit 110 is configured to interpret whether the digital value DV corresponds to the object distance DST, for example, the digit value "1010" corresponds to a distance of 10 cm from the object to be tested. The distance DST to be tested may also be a range, for example, 8 to 12 cm, and is not limited to a single fixed value. If the digital value DV corresponds to the object distance DST, the gain 2 ^M at this time is the parameter to be obtained in the embodiment of the present invention. If the digital value DV does not correspond to the object distance DST, the logic control unit 110 controls the light emitter 102, the light sensor 104, the reading circuit 106, and the analog digital converter 108 to perform the next round of testing until the digital value DV matches The distance to be tested is DST.

In the prior art, different surface properties of the object to be tested, differently designed translucent machine components, will result in different reflected light, making the gain become unsuitable, thereby affecting the accuracy of proximity sensor detection, the manufacturer needs By manually adjusting the gain to an appropriate value, it is a very inefficient production method. In contrast, the proximity sensor 10 of the embodiment of the present invention can consider the surface property of the object to be tested 100 and the variation of the translucent machine member 120, and the different reflected light Lrf is included in the adjustment gain 2 ^M in the production stage. Through the programmable calculation between components, the gain 2 ^M correction can be quickly completed, and the manufacturer can greatly shorten the production process.

The operation of proximity sensor 10 can be summarized as a programmable adjustment process 20, as shown in FIG. The adjustment process 20 includes the following steps:

Step 200: Start.

Step 202: The light emitter 102 transmits the emitted light Ltx toward the object to be tested 100 according to the emission period.

Step 204: Receive reflected light Lrf reflected from the object to be tested 100 by the emitted light Ltx.

Step 206: The photo sensor 104 converts the reflected light Lrf into a first analog signal A1.

Step 208: The reading circuit 106 selects an index M from the indices M1, M2, ... MN according to the search method.

Step 210: The read circuit 106 sets the gain to 2 ^M .

Step 212: The reading circuit 106 amplifies the first analog signal A1 as the second analog signal A2 according to the gain 2 ^M .

Step 214: The analog-to-digital converter 108 converts the second analog signal A2 to a digital value DV.

Step 216: The logic control unit 110 interprets the digital value DV.

Step 218: If the digital value DV corresponds to the object distance DST, step 220 is performed; otherwise, step 202 is performed.

Step 220: End.

In detail, in an embodiment of the invention, the indices M1, M2, ... MN are all integers. In addition, in step 208, the reading circuit 106 can select the largest index among the indices M1, M2, ... MN as the preset index M, and gradually search for the ideal index M by using a progressive binary search method. However, the search method is not limited to the binary search method. The binary search method ranks the possible indices M1, M2...MN from large to small before searching, and the effect is that each search narrows the search range to half of the previous search, which can reduce the number of times required to find the ideal index M. The binary search method is well known to those of ordinary skill in the art and will not be described here.

In addition to the gain, the present invention can also adjust the emission period of the light emitter 102. Please refer to FIG. 3, which is a flow chart of a programmable adjustment process 30 according to another embodiment of the present invention. The adjustment process 30 includes the following steps:

Step 300: Start.

Step 302: The light emitter 102 transmits the emitted light Ltx toward the object to be tested 100 according to the emission period.

Step 304: Receive reflected light Lrf reflected from the object to be tested 100 by the emitted light Ltx.

Step 306: The photo sensor 104 converts the reflected light Lrf into a first analog signal A1.

Step 308: The reading circuit 106 selects an index M from the indices M1, M2, ... MN according to the search method.

Step 310: The read circuit 106 sets the gain to 2 ^M .

Step 312: The reading circuit 106 amplifies the first analog signal A1 as the second analog signal A2 according to the gain 2 ^M .

Step 314: The analog-to-digital converter 108 converts the second analog signal A2 to a digital value DV.

Step 316: The logic control unit 110 interprets the digital value DV.

Step 318: If the digital value DV corresponds to the object distance DST, step 320 is performed; otherwise, step 302 is performed.

Step 320: If the gain 2 ^M is equal to a maximum gain, step 322 is performed; otherwise, step 324 is performed.

Step 322: Increase the transmission period Ttx and perform step 302.

Step 324: If the gain 2 ^M is equal to a minimum gain, step 326 is performed; otherwise, step 328 is performed.

Step 326: Reduce the transmission period Ttx and perform step 302.

Step 328: End.

In comparison with the adjustment process 20, the adjustment process 30 adds steps 320, 322, 324, 326 to adjust the emission period Ttx of the light emitter 102 when the gain 2 ^M reaches the threshold. In detail, in step 322, the pre-adjustment transmission period Ttx=2 ^K *T, where K is an integer, T is a time unit, and the adjusted transmission period Ttx is increased to Ttx=2 ^(K+1) *T . Conversely, in step 326, the pre-adjustment transmission period Ttx = 2 ^K * T, and the adjusted transmission period Ttx is decreased to Ttx = 2 ^(K-1) * T. The other steps of the adjustment process 30 are the same as those of the adjustment process 20, and are not described here.

It should be noted that the adjustment process 30 checks the upper and lower thresholds of the gain at the same time, and those skilled in the art can also check only the upper threshold or the lower threshold, that is, remove the steps 320, 322 or steps. 324, 326.

In addition, the proximity sensor 10 shown in FIG. 1 is an embodiment of the present invention, and those skilled in the art can make different modifications according to the present invention, and are not limited thereto. For example, please refer to FIG. 4, which is a schematic diagram of a proximity sensor 40 according to another embodiment of the present invention. Proximity sensor 40 is derived from proximity sensor 10, and like elements are indicated by the same symbols. The proximity sensor 40 further includes a drive circuit 412 as compared to the proximity sensor 10. The driving circuit 412 is configured to generate a driving signal DR according to the control of a logic control unit 410 to drive the light emitter 102 to generate the emitted light Ltx. Other components of the proximity sensor 40 are the same as the proximity sensor 10, and are not described herein.

It should be noted that the practical glazing sensor 104 receives not only the reflected light Lrf but also the ambient background light and the internal reflected light of the mechanism. Please refer to FIG. 5A. FIG. 5A is a schematic diagram of an ambient backlight Lsur and a mechanism internal reflected light Lrfm. When the light emitter 102 transmits light, part of the light is reflected by the translucent machine member 120, causing the light sensor 104 to additionally receive the internally reflected light Lrfm. In practical applications, the translucent machine member 120 may be a black plastic glass as an outer casing, which can protect the proximity sensor 10 from external collisions and allow the emitted light Ltx to penetrate. In addition, the ambient backlight Lsur can also be received by the photo sensor 104 through the translucent machine member 120. In this case, the photo sensor 104 receives the reflected light Lrf+environment background light Lsur+the internal reflection light Lrfm, and the generated first analog signal A1rsm is not the ideal first analog signal A1.

In order to exclude the ambient backlight Lsur and the internal reflection light Lrfm, please refer to FIGS. 5B and 5C, and FIG. 5B is a schematic diagram when the proximity sensor 10 does not transmit the emitted light Ltx. In the case of FIG. 5B, the photo sensor 104 receives only the ambient background light Lsur, and it is known that the first analog signal A1s corresponds to one of the ambient backlights Lsur. FIG. 5C is a schematic diagram of the proximity of the sensor 10 without the object to be tested. In the case of FIG. 5C, the photo sensor 104 receives the ambient background light Lsur and the in-system reflected light Lrfm, and can obtain a first analog signal A1sm corresponding to one of the internal reflection light Lrfm of the environmental background light Lsur. Since the first analog signal A1s corresponding to the ambient backlight Lsur is known, it is also known that the first analog signal A1m corresponding to one of the internal reflection light Lrfm is equal to A1sm-A1s. In this way, the first analog signal A1 corresponding to the reflected light Lrf alone is equal to A1rsm-A1s-A1m and can be obtained by conversion.

In other words, even if the proximity sensor 10 of the present invention is used in different applications (the translucent machine member 120 is different from the internal reflection light Lrfm) and in different environments (the ambient backlight Lsur is different), the corresponding correspondence can be correctly converted. The correct first analog signal A1 of the reflected light Lrf serves as a basis for adjusting the gain 2 ^M .

In summary, in view of the prior art method of manually adjusting the proximity sensor parameters, the present invention provides an automated rapid adjustment method, which can quickly obtain a suitable gain and emission period through a programmable progressive operation to accelerate the proximity. The production process of the detector. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10, 40‧‧‧ proximity sensor
100‧‧‧Test object
102‧‧‧Light emitter
104‧‧‧Light sensor
106‧‧‧Read circuit
108‧‧‧ analog digital converter
110, 410‧‧‧ logical control unit
120‧‧‧Translucent machine components
20, 30‧‧‧ adjustment process
200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 300, 302, 304, 306, 308, 310, 312, 314, 316, 318, 320, 322, 324, 326, 328‧‧‧Steps
412‧‧‧Drive circuit
Ltx‧‧‧ emitted light
Lrf‧‧·reflected light
Lsur‧‧‧Environmental background light
Lrfm‧‧‧ internal reflection light
DST‧‧‧Down object distance
A1‧‧‧first analog signal
A2‧‧‧Second analog signal
DV‧‧‧ digital value
DR‧‧‧ drive signal

FIG. 1 is a schematic diagram of a proximity sensor according to an embodiment of the present invention. FIG. 2 is a flow chart of an adjustment process according to an embodiment of the present invention. FIG. 3 is a flow chart of an adjustment process according to another embodiment of the present invention. FIG. 4 is a schematic diagram of a proximity sensor according to another embodiment of the present invention. Figure 5A is a schematic diagram of an ambient backlight and a reflected light inside a mechanism. Figure 5B is a schematic diagram of the proximity sensor of Figure 1 without transmitting a light. Fig. 5C is a schematic view of the first picture of the proximity sensor without the object to be tested.

10‧‧‧ proximity sensor

100‧‧‧Test object

102‧‧‧Light emitter

104‧‧‧Light sensor

106‧‧‧Read circuit

108‧‧‧ analog digital converter

110‧‧‧Logical Control Unit

120‧‧‧Translucent machine components

Ltx‧‧‧ emitted light

Lrf‧‧·reflected light

DST‧‧‧Down object distance

A1‧‧‧first analog signal

A2‧‧‧Second analog signal

DV‧‧‧ digital value

Claims (15)

An adjustment method for adjusting a gain of a Proximity Sensor and a launch period according to a distance of a test object, wherein the distance between the object to be tested is a distance between the proximity sensor and an object to be tested, The adjusting method includes: a first step of emitting a light toward the object to be tested according to the emission period; and a second step of receiving the reflected light to reflect light from the object to be tested; a third step of converting the reflected light into a first analog signal; a fourth step of selecting an index M from the plurality of indices according to a search method; and a fifth step of setting the gain to 2 ^M ; a sixth step of: amplifying the first analog signal as a second analog signal according to the gain; and a seventh step of converting the second analog signal to a digital value; wherein the first step to the seventh The steps are performed repeatedly until the digital value corresponds to the distance of the object to be tested. The adjustment method of claim 1, wherein the plurality of indices are integers, and the fourth step includes presetting a maximum one of the plurality of indices as the index M. The adjustment method of claim 1, wherein the search method is a binary search. The adjustment method of claim 1, further comprising an eighth step of increasing the transmission period when the gain is a maximum gain. The adjustment method of claim 4, wherein the transmission period is 2 ^K *T, K is an integer, and T is a time unit, wherein step 9 includes if the gain is the maximum gain, and the transmission period is increased by 2 ^(K+1) *T. The adjustment method of claim 1, further comprising a ninth step, wherein the transmission period is reduced when the gain is a minimum gain. The adjustment method of claim 6, wherein the transmission period is 2 ^K *T, K is an integer, and T is a time unit, and the ninth step includes if the gain is the minimum gain, and the emission period is decreased. 2 ^(K-1) *T. A Proximity Sensor, the proximity sensor is a distance from a test object to a test object, and the proximity sensor comprises: a light emitter for detecting the emission according to a launch period The object emits a light; a light sensor for receiving the reflected light from the object to be reflected, and converting the reflected light to a first analog signal; a reading circuit for The search method selects an index M from a plurality of indices, sets a gain to 2 ^M, and amplifies the first analog signal as a second analog signal according to the gain; an analog-to-digital converter (Analog-to-Digital Converter) , ADC), for converting the second analog signal to a digit value; and a logic control unit for interpreting whether the digit value corresponds to the distance of the object to be tested, wherein the logic control unit is further used to control the light emission The light sensor, the read circuit, and the analog digital converter repeatedly perform their functions until the digital value corresponds to the distance of the object to be tested. The proximity sensor of claim 8, wherein the plurality of indices are integers; wherein the reading circuit presets the largest one of the plurality of indices as the index M. The proximity sensor of claim 8, wherein the search method is a binary search. The proximity sensor of claim 8, wherein the logic control unit is further configured to increase the transmission period when the gain is a maximum gain. The proximity sensor of claim 11, wherein the transmission period is 2 ^K *T, K is an integer, and T is a time unit; wherein the logic control unit is further configured to use the gain as the maximum gain, Increase the transmission period to 2 ^(K+1) *T. The proximity sensor of claim 8, wherein the logic control unit is further configured to reduce the transmission period when the gain is a minimum gain. The proximity sensor of claim 13, wherein the emission period is 2 ^K *T, K is an integer, and T is a time unit; wherein the logic control unit is further configured to use the gain as the minimum gain, Reduce the emission period to 2 ^(K-1) *T. The proximity sensor of claim 8 further comprising a driving circuit for generating a driving signal to drive the light emitter to generate the emitted light according to the control of the logic control unit.