KR20200004757A - Beam projector module for performing eye-safety function using temperature, and control method thereof - Google Patents

Abstract

According to one embodiment, provided is a beam projector module comprising a light source for outputting a light, a substrate for supporting the light source, an optical device for reducing an intensity of the light outputted to a predetermined space with respect to the light, a frame which separates the light source device from the light source at a predetermined distance and forms a sealed space with the substrate and the optical device, a temperature sensor for measuring a temperature of the frame, and a processor for controlling an output of the light source, and the processor operates the light source in an eye-safety mode when a temperature drop rate of the frame exceeds a reference value. Therefore, an objective of the present embodiment is to provide a technique for the beam projector module which provides the eye-safety function.

Description

BEAM PROJECTOR MODULE FOR PERFORMING EYE-SAFETY FUNCTION USING TEMPERATURE, AND CONTROL METHOD THEREOF}

The present invention relates to a beam projector module.

LASER stands for "Light Amplification by Stimulated Emission of Radiation" and can output light intensively and condensed. In addition, lasers may have monochromaticity and directivity, which makes lasers widely used in the field of optical sensor technology.

For example, the laser may be used as a light source of a distance measuring device and may be used as a light source of a 3D depth camera. ToF (Time of Flight) distance measuring device measures the distance traveled by the pulse type light wave reflected from the light source through the phase difference and calculates the distance through the information of the phase difference and frequency. The structure light (SL) or hybrid stereo type (SL) may extract distance information by forming a regular or irregular pattern through a diffuser using a laser light source as a source.

Lasers are used as light sources for distance measurement and 3D depth cameras due to their high power and directivity.

On the other hand, the high power characteristics of the laser may be recognized as an advantage in terms of increasing the flight distance of the light, the output of the returned light can also be maintained at a certain level, but may be recognized as a disadvantage in terms of safety. If high power light is irradiated directly into the human eye, it may damage the eye and, in extreme cases, blindness. Therefore, safety issues should always be considered when using a laser as a light source.

In general, each country has an eye-safety criterion, so that the intensity of light output from the device is controlled below the reference value.

One method of controlling the intensity of the output light is to arrange a diffuser that can reduce the intensity of light on the light output path. Since the diffuser disperses the concentrated light to a certain field of view (FOV) required by the system through the effects of refraction and diffraction using the properties of light, the light passing through the diffuser is reduced in intensity per unit area.

By the way, in the apparatus for adjusting the intensity of light using the diffuser, when the diffuser is detached, it may be a problem for safety because the high output light is output as it is.

Against this background, it is an object of this embodiment to provide a technique for a beam projector module that provides an eye-safety function.

In order to achieve the above object, an embodiment includes a beam projector module, a light source for outputting light; A substrate supporting the light source; An optical device for reducing the intensity of the light output in a predetermined space with respect to the light; A frame spaced apart from the light source by a predetermined distance and forming an enclosed inner space together with the substrate and the optical device; A temperature sensor measuring a temperature of the beam projector module; And a processor configured to control an output of the light source, wherein the processor is configured to operate the light projector in an eye-safety mode when the temperature drop rate of the beam projector module exceeds a reference value. to provide.

In the beam projector module, the temperature sensor is connected to the frame to measure the temperature of the frame, and the processor, when the temperature drop rate of the frame exceeds a reference value, the eye light mode (eye-safety) mode).

In the beam projector module, the temperature sensor is connected to the optical device to measure the temperature of the optical device, and the processor, when the temperature drop rate of the optical device exceeds a reference value, the light source in the eye protection mode ( It can be operated in eye-safety mode.

In the beam projector module, the beam projector module includes two or more temperature sensors, one of the two or more temperature sensors is connected to the frame to measure the temperature of the frame, the other of the two or more temperature sensors to the optical device Connected to measure the temperature of the optics, and the processor may operate the light source in an eye-safety mode when the reference value of the temperature of the frame and the optics is exceeded.

In the beam projector module, the processor compares the temperature drop rate of the frame with the temperature drop rate of the optical device, extracts crack position information, and when the crack occurs in the optical device according to the crack position information, the light source. May operate the eye-safety mode.

In the beam projector module, the light source may include a vertical-cavity surface-emitting laser (VCSEL), and the optical device may include a diffuser for dispersing the light.

In the beam projector module, the processor may transmit temperature data of the beam projector module to the light receiving device, and the light receiving device may compensate for the temperature characteristic of the light by the optical device using the temperature data.

In another embodiment, a method of controlling a beam projector module including a light source and an optical device for reducing the intensity of light output from the light source, the method comprising: measuring, by a temperature sensor, a temperature of the beam projector module; And operating the light source in an eye-safety mode when the temperature drop rate of the beam projector module exceeds a reference value. It provides a control method comprising a.

In the control method, the temperature sensor measures a temperature of a frame supporting the optical device, and the processor is configured to turn the light source into an eye-safety mode when the temperature drop rate of the frame exceeds a reference value. ) Can be operated.

In the control method, the temperature sensor measures the temperature of the optical device, and the processor operates the light source in an eye-safety mode when the temperature drop rate of the optical device exceeds a reference value. You can.

In the control method, the temperature sensor measures the temperature of the internal space surrounded by the frame supporting the optical device, and the processor protects the light source when the temperature drop rate of the internal space exceeds a reference value. It can be operated in eye-safety mode.

In the control method, the temperature sensor measures the temperature of the optical device and the temperature of the frame supporting the optical device, and the processor, when the temperature drop rate of the optical device and the frame exceeds a reference value, The temperature drop rate of the optical device and the frame may be compared to extract crack position information, and when the crack occurs in the optical device, the light source may be operated in an eye-safety mode.

In the control method, the reference value may be calculated according to an external temperature measured by an external temperature sensor communicating with the processor outside of the beam projector module.

Estimating a temperature of the optical device using the temperature of the frame; It may further include.

In the control method, transmitting the temperature of the optical device to the light receiving device; Obtaining, by the light receiving device, an optical value of the optical device by using the temperature of the optical device; And the light receiving device compensates for the received light value according to the optical value. It may further include.

As described above, according to the present embodiment, even if an abnormality occurs in the beam projector module, it is possible to safely protect the eyes of the user.

1 is a view showing that the beam projector module according to the first embodiment is operating normally.
2 is a first view showing that the beam projector module according to the first embodiment is abnormally operating.
3 is a second view showing that the beam projector module according to the first embodiment is abnormally operating.
4 is a third view showing that the beam projector module according to the first embodiment is abnormally operating.
5 is a diagram illustrating that the beam projector module according to the second embodiment is operating normally.
6 is an exemplary graph of a temperature change according to a change in time of a beam projector module according to an embodiment of the specification.
7 is an exemplary graph of temperature change of the beam projector module in each external environment according to the first embodiment or the second embodiment.
8 is a flowchart of a method of operating the eye protection function of the beam projector module according to the first or second embodiment.
9 is a first view showing that the beam projector module having a plurality of temperature sensors according to the third embodiment is abnormally operating.
FIG. 10 is a second view showing that the beam projector module having a plurality of temperature sensors according to the third embodiment is abnormally operated.
11 is a flowchart of a method of operating the eye protection function of the beam projector module according to the third embodiment.
12 is an exemplary graph of a temperature change of the beam projector module.
FIG. 13 is an exemplary graph illustrating an optical value according to a temperature of a beam projector module. FIG.
14 is a flowchart of a method of compensating for a temperature characteristic of a beam projector module in an optical system according to an embodiment of the present disclosure.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, if it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the component of this invention, terms, such as 1st, 2nd, A, B, (a), (b), can be used. These terms are only for distinguishing the components from other components, and the nature, order or order of the components are not limited by the terms. If a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to that other component, but there may be another configuration between each component. It is to be understood that the elements may be "connected", "coupled" or "connected".

1 is a view showing that the beam projector module according to the first embodiment is operating normally.

Referring to FIG. 1, the beam projector module 100 may include a light source 110, a substrate 120, a frame 130, an optical device 140, a temperature sensor 150, a processor 160, and the like. .

Wiring may be patterned on the substrate 120. In addition, the substrate 120 may receive power from the outside, and the power may be supplied to the light source 110, the temperature sensor 150, the processor 160, or the like through each wire. The substrate 120 may be formed of a material having a low thermal resistance or a thermally conductive material.

The light source 110 may be disposed on the substrate 120, the anode electrode of the light source 110 may be connected to the anode wiring of the substrate 120, and the cathode electrode may be connected to the cathode wiring of the substrate 120. The light source 110 may be connected to the substrate 120 in the form of wire bonding. Alternatively, the light source 110 may be disposed without wires on the substrate 120 through flip chip bonding. When the light source 110 is connected to the substrate 120 through flip chip bonding, there is no wire line and thus a smaller beam projector module can be configured.

The light source 110 may output light toward the optical device 140. One light source 110 may be disposed, or two or more light sources 110 may be disposed. The light source 110 may be a light source that outputs light in a single wavelength region, or may be a light source 110 that outputs light having a plurality of wavelength regions by separately configuring a portion of the light source 110.

The light source 110 may include a vertical-cavity surface-emitting laser (VCSEL).

Power supply to the light source 110 may be controlled by the processor 160. The processor 160 may differently control the power supplied to the light source 110 in the normal mode and the eye protection mode.

For example, the processor 160 may supply power to the light source 110 only in the normal mode and may not supply power to the light source 110 in the eye protection mode. Alternatively, the processor 160 may lower the level of power supplied to the light source 110 in the eye protection mode than in the normal mode. Thus, the intensity of light output from the light source 110 can be reduced.

The optical device 140 may be spaced apart from the light source 110 by a frame 130. The optical device 140 may reduce the intensity of light output in a predetermined space with respect to the light output from the light source 110.

Optical device 140 may include a diffuser. The diffuser may reduce the intensity of light output to a predetermined space by dispersing the light output from the light source 110.

The frame 130 may be supported by the substrate 120. The frame 130 may support the optical device 140.

An inner space 10 sealed by the substrate 120, the frame 130, and the optical device 140 may be formed. Air formed in the sealed inner space 10 may not circulate to the outside or circulate with the outside at a very small level. The substantially sealed interior space 10 may have convection internally, but heat exchange with the outside may be performed only through the substrate 120, the frame 130, and the optical device 140 constituting the sealed interior space 10. Can be done.

The frame 130 may be made of a material having low thermal resistance or a conductive material. The frame 130 may contact one side of the optical device 140 and the other side of the frame 130. By such a configuration, the frame 130 may function as a heat path for discharging heat formed in the optical device 140 toward the substrate 120.

The light source 110 is a device for converting electricity into light, and according to the conversion efficiency, a predetermined or more electric energy may be emitted as heat. Heat emitted from the light source 110 may be transmitted to the optical device 140 mainly located on the upper surface. In addition, the temperature of the optical device 140 may increase according to the heat generated by the light source 110. The heat of the optical device 140 may flow to the substrate 120 along the frame 130 having low thermal resistance.

In the substrate 120 or on the substrate, a temperature sensor 150 capable of measuring the temperature of the frame 130 may be disposed.

The temperature sensor 150 may be connected to the frame 130 to measure the temperature of the frame 130.

Heat emitted from the light source 110 is transmitted to the optical device 140, heat of the optical device 140 is transmitted through the frame 130, and heat transmitted to the frame 130 is transferred from the temperature sensor 150. The temperature of the frame 130 may be measured. The temperature value of the frame measured by the temperature sensor 150 may be transmitted to the processor 160.

In another embodiment, the temperature sensor 150 may be disposed inside the substrate 120 or the frame 130 to measure the temperature of the sealed inner space 10. Therefore, the processor 160 may obtain a temperature value of the sealed inner space 10.

2 is a first view showing that the beam projector module according to the first embodiment is abnormally operating.

Referring to FIG. 2, the optical device 140 may leave the frame 130 for some reason. When the optical device 140 is detached from the frame 130, the sealed inner space 10 in the normal operation may be changed into the open inner space 20a.

The heat emitted from the light source 110 may flow to the outside through the open internal space 20a. In the case of the enclosed interior space, the heat trapped therein can be discharged to the outside only through the outer wall constituting the sealed space-the substrate 120, the frame 130 and the optical device 140, but the open interior space ( In 20a), the heat generated inside can be easily released to the outside through convection.

As such, when the optical device 140 is detached from the frame 130, the temperature of the internal space is lowered. In addition, a large amount of heat transmitted to the optical device 140 in the closed interior space is also reduced in the open interior space. Then, the amount of heat transferred to the frame 130 is also reduced, the temperature of the frame 130 is also lowered. In addition, the reduced temperature of the frame 130 may be measured by the temperature sensor 150, and the temperature value measured by the temperature sensor 150 may be measured lower than when the beam projector 100 normally operates.

The processor 160 may determine whether the optical device 140 is attached or detached by sensing the temperature change of the frame 130.

When the optical device 140 is detached, a strong intensity of light emitted from the light source may not be dispersed, and thus may be a safety problem since the optical device 140 may reach the user's eyes directly.

Accordingly, the processor 160 determines whether the optical device 140 is attached or detached based on the temperature change of the frame 130, and when the optical device 140 is determined to be detached, the processor 160 sets the light source 110 to the eye protection mode. safety mode).

The processor 160 may stop supplying power to the light source 110 in an eye-safety mode. Therefore, when the optical device 140 is detached, the operation of the light source 110 may be stopped by the processor 160, and the eyes of the user may be protected.

In addition, the processor 160 may lower the power supply level to the light source 110 in the eye-safety mode than in normal driving. For example, the current flowing to the light source 110 may be reduced. Therefore, when the optical device 140 is detached, the intensity of light output from the light source 110 by the processor 160 may be reduced, and the eyes of the user may be protected.

On the other hand, when the temperature sensor 150 measures the temperature of the closed interior space 10, the optical device 140 is detached to open the internal space and the heat of the open internal space 20a is discharged to the outside to the inside The temperature of the space 20a may drop. The processor 160 may obtain a rate of temperature drop of the internal space 20 through the temperature sensor 150.

3 is a second view showing that the beam projector module according to the first embodiment is abnormally operating.

4 is a third view showing that the beam projector module according to the first embodiment is abnormally operating.

3 to 4, the optical device 140 may generate cracks 50a and 50b in a part of the optical device 140 for some reason.

When the crack 50a occurs in the center portion of the optical device 140 as shown in FIG. 3, heat emitted from the light source 110 may be transferred to the optical device 140, and the heat of the optical device 140 may be cracked. 50a) may be transmitted to the frame 130 through the heat path of the portion where the portion does not occur.

However, external air having a relatively low temperature may be introduced through a portion where the crack 50a is generated, and heat may radiate to the outside of the beam projector 100. That is, the sealed internal space can be opened by the crack 50a on the optical device.

Therefore, the temperature of the frame 130 may be relatively lower than when the crack 50a does not occur in the optical device 140.

When the crack 50b is generated close to the connection portion between the optical device 140 and the frame 130 as shown in FIG. 4, the heat path is blocked so that the heat emitted from the light source 110 passes through the optical device 140. 130 may be difficult to deliver.

However, even in this case, heat is dissipated to the outside of the beam projector 100 through the crack 50b, and the temperature of the frame 130 may be lowered due to external air introduced through the gap of the crack 50b. . Therefore, even when a crack 50b occurs in the connection portion between the optical device 140 and the frame 130, the temperature of the frame 130 may be relatively lower than that in the normal case.

When the cracks 50a and 50b occur, the temperature sensor 150 may transmit a relatively low temperature value to the processor 160, and the processor 160 operates an eye-safety mode. Lowering the power delivered to the light source 110, or stops the power supply to lower the intensity of the light emitted from the light source 110, or do not emit light to protect the eyes of the user when the crack (50a, 50b) occurs can do.

Therefore, when cracks 50a and 50b occur in a part of the optical device 140, the eye-safety mode may be operated through temperature measurement and the user's eyes may be safely protected.

On the other hand, even when the temperature sensor 150 measures the temperature of the closed space 10, the temperature of the closed space 10 can be lowered according to the crack generation. In this case, the processor 160 may acquire the temperature drop rate through the temperature sensor 150, and may drive the light source 110 in an eye-safety mode.

5 is a diagram illustrating that the beam projector module according to the second embodiment is operating normally.

Referring to FIG. 5, the beam projector module 200 may include a light source 110, a substrate 120, a frame 130, an optical device 140, a temperature sensor 250, and a processor 160. . In addition, the temperature sensor 250 may be disposed on a part of the upper side of the frame 130 and may be arranged to be connected to the optical device 250.

Meanwhile, the wires connecting the temperature sensor 250 and the substrate 120 may be connected through the inside of the frame 130 or through the surface of the frame 130.

When the temperature sensor 250 is disposed to contact the optical device 140, the temperature of the optical device 140 may be directly measured without measuring the temperature through the heat transmitted through the frame 130. It may be possible to accurately measure the temperature of the optics 140.

For example, when a defect occurs simultaneously on the frame 130 and the optical device 140 for some reason, the heat emitted from the light source 110 is blocked from the heat path due to the defect on the frame 130 and thus the substrate 120. Can be difficult to deliver. However, when the temperature sensor 250 is directly attached to the optical device 140, despite the defect of the frame 130, it is possible to accurately measure the temperature change of the optical device 140.

In addition, when the temperature sensor 250 is disposed to be connected to the optical device 140, the heat path through which the heat emitted from the light source 110 is transferred to the temperature sensor 250 may be shortened. Therefore, the processor 160 may measure the temperature drop rate more sensitively than when heat is transferred through the frame 130.

In addition, the beam projector module 200 may include an additional sealing material to maintain a sealed space between the temperature sensor 250 and the optical device 140. The sealant may be thermally conductive or low in thermal resistance, and may transfer heat from the optical device 140 to the temperature sensor.

The processor 160 calculates a temperature drop rate according to the temperature change of the optical device 140 measured by the temperature sensor 250, and compares it with a reference value to operate the light source 110 in an eye-safety mode. Can be driven.

6 is an exemplary graph of a temperature change according to a change in time of the beam projector module according to the first embodiment or the second embodiment.

1 to 5 and 6, when the beam projector module is started, the temperature of the optical device 140 increases due to the heat generated by the light source 110 in the initial operation section Ta, and the optical device 140. The temperature of the frame 130 located in the path of heat emitted from the may rise. In addition, the temperature of the sealed inner space 10 may also increase.

The temperature of the beam projector modules 100 and 200, or the temperature of the optical device 140, the frame 130 and the enclosed inner space 10, respectively, rises to a certain level and then maintains a thermal equilibrium with the outside. Can be maintained.

On the other hand, when the optical device 140 forming a closed space in the beam projector module (100, 200) is detached from the frame 130, the temperature of the beam projector module (100, 200), the frame 130, the optical device 140 is lowered It has a crack generation section (Tb), the temperature of the optical device 140, the frame 130 and the sealed space 10 can be sharply lowered.

In addition, even when a crack occurs in a part of the optical device 140 to open the sealed internal space, the temperatures of the optical device 140, the frame 130, and the internal space 10 may be lowered.

The processor 160 may have a reference value for the beam projector modules 100 and 200, the frame 130, the optical device 140, and the temperature drop rate D of the internal space.

The reference value may be previously calculated in consideration of the material of the frame 130, the optical device 140, the substrate 120, or the external environment of the mobile terminal in which the beam projector modules 100 and 200 are installed. For example, when the frame 130 and the optical device 140 are formed of a material having high thermal conductivity, the reference value may be larger. On the other hand, when the frame 130 and the optical device 140 are formed of a material having a low thermal conductivity, the reference value may be relatively low.

The processor 160 may calculate a temperature drop rate D based on the temperature values measured by the temperature sensors 150 and 250, and compare the calculated temperature drop rate D with a reference value.

The beam projector modules 100 and 200 compare the temperature drop rate D of the optical device 140, the frame 130, and the internal space 10 with a reference value, and determine whether the optical device 140 is detached or not. It is possible to determine whether or not the crack on the 140).

The processor 160 operates the light source 110 in an eye-safety mode when the temperature drop rate of the beam projector modules 100 and 200, the frame 130, the optical device 140, and the internal space exceeds a reference value. ) And stop the transmission of power to the light source 110 or reduce the amount of power so that the light source 110 does not output light or reduce the intensity of light output from the light source 110.

7 is an exemplary graph of temperature change of the beam projector module in each external environment according to the first embodiment or the second embodiment.

Referring to FIG. 7, the reference value of the temperature drop rate may be different in consideration of an external environment in which the beam projector modules 100 and 200 are installed.

The beam projector modules 100 and 200 may include an external temperature sensor disposed outside the beam projector modules 100 and 200 and measuring an external temperature. The external temperature sensor measures the temperature outside the beam projector module (100, 200). The processor 160 may differently calculate a reference value of the temperature drop rate in consideration of the external environment.

For example, when (A) the beam projector module is operated in a low temperature environment, the temperature increase rate in the initial heating section Tla may be greater than the temperature increase rate of the initial heating section Tha in the high temperature environment. . In addition, the temperature drop rate D 'in the crack generation section Tlb in the low temperature environment may be greater than the temperature drop rate D ″ of the crack generation section Thb in the high temperature environment.

Accordingly, the processor 160 calculates a reference value of the temperature drop rate in each environment in consideration of the external temperature measured by the external temperature sensor, and determines whether a crack has occurred by comparing the temperature drop rate with the reference value calculated according to the situation. Can be.

8 is a flowchart of a method of operating the eye protection function of the beam projector module according to the first or second embodiment.

1 to 8, the temperature sensors 150 and 250 measure the temperature of the frame 130 supporting the optical device 140, the optical device 140, and the internal space, and the processor 160 measures the temperature sensor. By comparing the drop rate of the temperature measured in advance with a reference value calculated in advance, it can be determined that the temperature decrease rate is higher or lower than the reference value (S102).

In this case, the reference value may be appropriately calculated through the relationship with the external temperature by using the external temperature sensor.

When the temperature reduction rate of the frame 130, the optical device 140, and the internal space does not exceed the reference value, the processor 160 may operate the light source 110 in the normal mode (S104).

On the other hand, when the temperature reduction rate of the frame 130, the optical device 140 and the internal space exceeds the reference value, the processor 160 may operate the light source 110 in an eye-safety mode (eye-safety mode) ( S106).

9 is a first view showing that the beam projector module having a plurality of temperature sensors according to the third embodiment is abnormally operating.

FIG. 10 is a second view illustrating abnormal operation of a beam projector module having a plurality of temperature sensors according to a third embodiment.

9 and 10, the beam projector module may include two or more temperature sensors.

In addition, one temperature sensor 351 of the two or more temperature sensors may be connected to the frame 130 to measure the temperature of the frame 130, the other one of the two or more temperature sensors 352 of the optical device The temperature of the optical device 140 may be measured by being connected to the 140.

Each of the two or more temperature sensors may be individually connected to the processor 160, measure the temperature of the frame 130 and the optical device 140, and transmit a temperature value to the processor 160.

Referring to FIG. 9, cracks may occur in the frame 130 for some reason.

When a crack occurs in the frame 130, the amount of heat emitted from the light source 110 is greatly reduced through the frame 130 because the crack reduces the heat path transmitted through the frame 130. have.

On the other hand, since the thermal path to the optical device 140 is maintained even if a crack occurs in the frame 130, the amount of heat emitted from the light source 110 is transmitted through the optical device 140 compared to the frame 130. You can write it down.

Therefore, when a crack occurs in the frame 130, the rate of decrease of the temperature measured by the temperature sensor 351 connected to the frame may be greater than the rate of decrease of the temperature measured by the temperature sensor 352 connected to the optical device.

In addition, the processor 160 compares the temperature drop rates measured by the respective temperature sensors 351 and 352, and when the temperature drop rate of the frame 130 is greater than the temperature drop rate of the optical device 140, the crack is frame 130. It can be judged that occurred in.

Referring to FIG. 10, cracks may occur on the optical device 140 for some reason.

When the crack occurs in the optical device 140, the heat path through the optical device 140 is reduced, as opposed to when the crack occurs in the frame 130, the optical device 140 than the temperature drop rate of the frame 130 The rate of temperature drop can be large.

Accordingly, the processor 160 compares the temperature drop rates measured by the respective temperature sensors 351 and 352, and if the temperature drop rate of the optical device 140 is greater than the temperature drop rate of the frame 130, the cracks may be used in the optical device ( 140 may occur.

Meanwhile, the optical device 140 and the frame 130 may be different materials, and thus, thermal conductivity may be different. In addition, the processor 160 may correct the temperature drop rate in consideration of the thermal conductivity of the frame 130 and the optical device 140. In addition, the processor 160 may determine a crack occurrence position by comparing the corrected temperature drop rate.

11 is a flowchart of a method of operating the eye protection function of the beam projector module according to the third embodiment.

9 to 10 and 11, the temperature sensors 351 and 352 may measure the temperature of the optical device 140 and the frame 130, and the processor 160 may measure the optical device 140 and the frame ( It may be determined whether the temperature drop rate of 130 exceeds the reference value (S202).

When the temperature drop rate of at least one of the optical device 140 and the frame 130 exceeds a reference value, the processor 160 compares the temperature drop rates of the optical device 140 and the frame 130 with the crack position information. Can be extracted (S204).

When the crack does not occur in the optical device 140 according to the crack position information, the processor 160 may operate the light source 110 in the normal mode (S208).

When the crack occurs in the optical device 140 according to the crack position information, the processor 160 may operate the light source 110 in an eye-safety mode (S210).

On the other hand, according to the operation of the eye-safety mode (eye-safety mode) only when a crack occurs in the optical device 140, when a crack occurs in the frame 130 that is not significantly associated with the safety of the user, the beam projector module 300 ) Can be driven normally. Therefore, it is possible to improve the operating efficiency of the beam projector module 300 by driving the eye-safety mode only when it is related to the safety of the user.

12 is an exemplary graph of a temperature change of the beam projector module.

FIG. 13 is an exemplary graph illustrating an optical value according to a temperature of a beam projector module. FIG.

12 and 13, the temperature of the optical device may be changed by an external environment. For example, if the user is located in a tropical area, the optics may be exposed to a high temperature environment and the temperature may be kept high. As another example, the optics can be kept cold if the user is located in a well-cooled space.

Alternatively, in the case of the beam projector module mounted on the mobile device, the external temperature of the beam projector module may be different according to the environment installed in each mobile device, and thus the temperature of the optical device may be different according to the installation environment.

The optical value of the optical device may vary depending on the temperature of the optical device. For example, the refractive index of the optics can vary. As another example, the light transmittance of the optical device may vary. As shown in FIG. 13, depending on the temperature, the optical value of ML may be low at low temperatures and the optical value of MH at high temperatures.

When the optical value is changed with respect to the light receiving device adjusted to the constant optical value, the reception accuracy of the light receiving device may be lowered.

In order to solve this problem, an optical system including a beam projector module and a light receiving device can check the temperature of the optical device and correct the optical value according to the temperature of the optical device. In addition, the light receiving device may sense the light output from the beam projector module according to the corrected optical value.

14 is a flowchart of a method of compensating for a temperature characteristic of a beam projector module in an optical system according to an embodiment of the present disclosure.

Referring to FIG. 14, the beam projector module may include a processor and measure the temperature of the frame and the optical device. The frame may provide a thermal path for supporting the optical device and transferring heat generated by the optical device to the substrate or the like. The beam projector module may sense the temperature of the thermal path through the temperature measurement for the frame (S302).

The beam projector module may estimate the temperature of the optical device, for example, a diffuser, or directly measure the temperature of the optical device using the frame temperature (S304).

The beam projector module may transmit the temperature of the optical device to the light receiving device.

The light receiving device may obtain an optical value of the optical device by using the temperature of the optical device. The light receiving device stores, for example, information indicating a relationship between a temperature and an optical value, for example, a function, a table, and the like, as shown in FIG. An optical value of the device may be obtained (S306).

In operation S308, the light receiving apparatus may compensate for the received light value according to the optical value.

As described above, according to the present embodiment, even if an abnormality occurs in the beam projector module, it is possible to safely protect the eyes of the user.

The terms "comprise", "comprise" or "having" described above mean that a corresponding component may be included unless specifically stated otherwise, and thus does not exclude other components. It should be construed that it may further include other components. All terms, including technical and scientific terms, have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms commonly used, such as terms defined in a dictionary, should be interpreted to coincide with the contextual meaning of the related art, and shall not be construed in an ideal or excessively formal sense unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (15)

In the beam projector module,
A light source for outputting light;
A substrate supporting the light source;
An optical device for reducing the intensity of the light output in a predetermined space with respect to the light;
A frame spaced apart from the light source by a predetermined distance and forming an enclosed inner space together with the substrate and the optical device;
A temperature sensor measuring a temperature of the beam projector module; And
A processor for controlling the output of the light source,
The processor,
And a beam projector module operating the light source in an eye-safety mode when the temperature drop rate of the beam projector module exceeds a reference value. The method of claim 1,
The temperature sensor is connected to the frame to measure the temperature of the frame,
And the processor operates the light source in an eye-safety mode when the temperature drop rate of the frame exceeds a reference value. The method of claim 1,
The temperature sensor is connected to the optical device to measure the temperature of the optical device,
And the processor operates the light source in an eye-safety mode when the temperature drop rate of the optical device exceeds a reference value. The method of claim 1,
The beam projector module includes two or more temperature sensors,
One of the two or more temperature sensors is connected to the frame to measure the temperature of the frame,
The other of the two or more temperature sensors is connected to the optics to measure the temperature of the optics,
And the processor operates the light source in an eye-safety mode when the reference value of the temperature of the frame and the optical device is exceeded. The method of claim 4, wherein
The processor,
Comparing the temperature drop rate of the frame with the temperature drop rate of the optical device, extracting crack position information,
And operating the eye-safety mode when the crack occurs in the optical device according to the crack position information. The method of claim 1,
The light source comprises a vertical-cavity surface-emitting laser (VCSEL),
The optical device includes a beam projector module comprising a diffuser for dispersing the light. The method of claim 1,
The processor transmits the temperature data of the beam projector module to the light receiving device,
And the light receiving device compensates for the temperature characteristic of the light by the optical device using the temperature data. In the method for controlling a beam projector module comprising a light source and an optical device for reducing the intensity of light output from the light source,
Measuring, by a temperature sensor, the temperature of the beam projector module; And
Operating the light source in an eye-safety mode when the temperature drop rate of the beam projector module exceeds a reference value;
Control method comprising a. The method of claim 8,
The temperature sensor measures the temperature of the frame supporting the optical device,
And the processor operates the light source in an eye-safety mode when the rate of temperature drop of the frame exceeds a reference value. The method of claim 8,
The temperature sensor measures the temperature of the optical device,
And the processor operates the light source in an eye-safety mode when the rate of temperature drop of the optical device exceeds a reference value. The method of claim 8,
The temperature sensor measures the temperature of the internal space surrounded by the frame for supporting the optical device,
And the processor operates the light source in an eye-safety mode when the temperature drop rate of the internal space exceeds a reference value. The method of claim 8,
The temperature sensor measures the temperature of the optical device and the temperature of the frame supporting the optical device,
When the temperature drop rate of the optical device and the frame exceeds a reference value, the processor extracts crack position information by comparing the temperature drop rate of the optical device and the frame, and when the crack occurs in the optical device, the light source. Operating in an eye-safety mode. The method of claim 8,
The reference value is,
Is calculated according to the external temperature measured by an external temperature sensor in communication with the processor outside the beam projector module,
Control method. The method of claim 8,
Estimating the temperature of the optical device using the temperature of the frame;
Further comprising, the control method. The method of claim 14,
Transmitting the temperature of the optical device to the light receiving device;
Obtaining, by the light receiving device, an optical value of the optical device by using the temperature of the optical device; And
Compensating for a light receiving value by the light receiving device according to the optical value;
Further comprising, the control method.

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