CN111722397A

CN111722397A - Laser scanning projection device and equipment

Info

Publication number: CN111722397A
Application number: CN201910218569.8A
Authority: CN
Inventors: 不公告发明人
Original assignee: Chengdu Idealsee Technology Co Ltd
Current assignee: Chengdu Idealsee Technology Co Ltd
Priority date: 2019-03-21
Filing date: 2019-03-21
Publication date: 2020-09-29

Abstract

The invention provides a laser scanning projection device and equipment, which are used for solving the technical problem of low safety of a scanner in the scanning projection process. The laser scanning projection device comprises a light source, a scanner and an optical detector, wherein the light source is used for emitting image light of an image to be displayed, the scanner is used for scanning and emitting the image light to form scanning light, the optical detector is arranged on an emitting light path of the scanner and used for detecting light energy of the scanning light and transmitting the scanning light.

Description

Laser scanning projection device and equipment

Technical Field

The invention relates to the technical field of laser scanning display, in particular to a laser scanning projection device and equipment.

Background

The optical fiber resonance piezoelectric scanner is a new type scanner which utilizes the resonance characteristic of the optical fiber cantilever in the orthogonal direction to realize the static or dynamic image scanning function. The micro-projection device can be used as a micro-projection device to replace the traditional LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode) and LCOS (Liquid Crystal on Silicon), is integrated into devices such as a non-screen television, a smart phone, a vehicle-mounted/airborne Display, an AR (Augmented Reality)/VR (Virtual Reality) helmet and the like, and has a good application prospect.

Currently, in the optical fiber scanning display technology, the energy of the laser light source is high. If a scanning imaging system has a problem, which may cause the scanner to stop scanning (i.e. to stop swinging), the radiation accumulation and light pressure of a single point of the direct light and the scattered light of the laser will gradually increase, causing certain damage to human eyes, skin and a projection carrier (such as a screen), so that a potential safety hazard exists, but the existing laser scanning system has no corresponding detection capability.

Disclosure of Invention

The embodiment of the invention aims to provide a laser scanning projection device and equipment, which are used for improving the data monitoring capability of a laser scanning system in the scanning projection process and improving the safety of the system.

In order to achieve the above object, in a first aspect, the present invention provides a laser scanning projection apparatus, including a light source, a scanner, and an optical detector, where the light source is configured to emit image light of an image to be displayed, the scanner is configured to scan and emit the image light to form scanning light, and the optical detector is disposed on an emission light path of the scanner, and is configured to detect light energy of the scanning light and transmit the scanning light.

Optionally, the laser scanning projection apparatus further includes a controller, connected to the light detector, and configured to determine whether the value of the light energy is greater than a preset threshold, and control the emergent light of the scanner when it is determined that the value of the light energy is greater than the preset threshold.

Optionally, the laser scanning projection apparatus further includes:

the light source driver is respectively connected with the controller and the light source and used for turning off the light source or reducing the driving voltage of the light source according to the instruction of the controller; and/or

And the light chopper is arranged between the scanner and the projection carrier corresponding to the scanner and used for blocking a projection light path of the scanner according to the instruction of the controller.

Optionally, the light detector is a transmission type light detector.

Optionally, the scanner is a fiber scanner or a MEMS scanner.

Optionally, if the scanner is an optical fiber scanner, the optical fiber scanner includes an actuator and an optical fiber fixed on the actuator, an end of the optical fiber beyond the actuator forms an optical fiber cantilever, and the actuator drives the optical fiber cantilever to vibrate under the action of a driving signal.

Optionally, the optical fiber scanner further includes a projection objective disposed on an exit light path of the optical fiber scanner, and configured to image the scanning surface at the end of the optical fiber cantilever onto the projection surface corresponding to the optical fiber scanning.

In a second aspect, an embodiment of the present invention provides a detection method, applied to a laser scanning projection apparatus, where the laser scanning projection apparatus includes a light source, a scanner, and an optical detector, where the optical detector is located on an exit light path of the scanner, and the detection method includes:

controlling a light source in the laser scanning projection device to emit image light corresponding to an image to be displayed, and scanning and emitting the image light through a scanner to form scanning light;

and transmitting the scanning light through a light detector, and detecting the light energy of the scanning light.

Optionally, after detecting the light energy of the scanning light line, the method further includes:

judging whether the value of the detected light energy is larger than a preset threshold value or not;

and if the light energy value is determined to be larger than the preset threshold value, controlling emergent light of the scanner.

In a third aspect, an embodiment of the present invention provides a laser scanning projection apparatus, which includes the laser scanning projection device according to the first aspect.

One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

in summary, in the embodiment of the invention, the laser scanning projection apparatus can detect the light energy of the scanning light emitted by the scanner through the optical detector arranged on the emitting light path of the scanner, so that the light energy condition of the scanning light emitted by the scanner can be monitored in real time through the optical detector in the scanning projection process of the laser scanning projection apparatus, which is beneficial to improving the safety of the laser scanning projection apparatus.

Drawings

FIG. 1 is a first schematic structural diagram of a laser scanning projection apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of an optical fiber scanner employed by the laser scanning projection apparatus according to the embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a laser scanning projection apparatus using a MEMAS scanner according to an embodiment of the present invention;

FIG. 4 is a power spectrum of a photodetector test in an embodiment of the invention;

FIG. 5 is a schematic diagram of a power spectrum corresponding to a normal operating state of a scanner according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a power spectrum corresponding to an abnormal operation of a scanner according to an embodiment of the present invention;

FIG. 7 is a flowchart of a detection method according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In this embodiment of the present invention, "and/or" is an association relationship used to describe an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" generally indicates that the preceding and following related objects are in an "or" relationship, unless otherwise specified.

Fig. 1 is a schematic structural diagram of a laser scanning projection apparatus provided in an embodiment of the present invention, where the laser scanning projection apparatus includes a light source 10, a scanner 20, and a light detector 30; wherein, the light detector 30 is disposed on the emergent light path of the scanner 20, and is used for transmitting the scanning light emitted by the scanner 20; the scanner 20 may be a fiber scanner, a MEMS scanner, a DMD chip, or the like.

It should be noted that fig. 1 is only an example of a laser scanning projection apparatus provided in an embodiment of the present invention, and a scanner of the laser scanning projection apparatus is taken as an optical fiber scanner in the drawing as an example. In addition, the laser scanning projection apparatus provided by the embodiment of the present invention may further include other components, such as a base, a housing, a projection carrier (e.g., a projection curtain) corresponding to the scanner, and the like, which are not shown in fig. 1.

In the embodiment of the present invention, the laser emitted from the light source 10 enters the scanner 20, the scanner 20 periodically scans and emits the scanning light corresponding to the image to be displayed, and then the optical detector 30 located in the emitting light path of the scanner 20 can detect the light energy of the scanning light and transmit the scanning light, and the transmitted scanning light can reach the projection carrier corresponding to the scanner 20 to form the projection image. Therefore, the optical detector is arranged on the emergent light path of the scanner in the optical scanning projection device, so that the information such as the light energy of the scanning light emitted by the scanner can be detected, more reliable working data can be provided for the laser scanning projection device, and the safety of the device can be improved.

In order to make those skilled in the art understand the technical solutions provided by the embodiments of the present invention, the laser scanning projection apparatus provided by the embodiments of the present invention is described in detail below.

The light source 10, including a laser, such as a solid state laser, emits imaging light into the scanner 20. In practical applications, the laser scanning projection device may provide an image source through the storage medium and the microprocessor, and the microprocessor may perform the internal/external modulation on the light source 10 to emit modulated laser (i.e., imaging light) corresponding to the image source according to the image source.

In practical applications, the light source 10 may include R, G, B three light emitting units, one light emitting unit may be a single monochromatic laser, and R, G, B three light emitting units correspond to R, G, B three monochromatic lasers (R, G, B three monochromatic lasers refer to red, green and blue lasers, respectively); alternatively, a lighting unit may include a plurality of light emitters, for example, an R lighting unit may be formed by mixing two light emitters R' and R ″, and when each lighting unit includes a plurality of light emitters, light energy may be increased. The light source 10 in the embodiment of the present invention may adopt a corresponding light emitting unit according to actual requirements, and is not limited herein.

The scanner 20 is located on the light emitting path of the light source 10, and can receive the laser light incident from the light source 10 and emit scanning light to form a scanning projection image.

In the embodiment of the present invention, the scanner 20 in the laser scanning projection apparatus may include, but is not limited to, the following cases:

(1) the scanner 20 is a fiber optic scanner.

In the embodiment of the present invention, the scanner 20 may be a fiber resonance type piezoelectric scanner, i.e. a new type scanner that emits static or dynamic images by using the swing of the fiber cantilever. Referring to fig. 2, the optical fiber scanner may include a base 201, an optical fiber 202, an actuating portion 203, and other components, the optical fiber 202 is fixed on the actuator 203, and an end of the optical fiber 202 beyond the actuator 203 forms an optical fiber cantilever, and the actuator 203 may drive the optical fiber cantilever to vibrate under the action of a driving signal.

The input end of the optical fiber 202 is optically coupled to the light source 10, and may be coupled to an optical fiber or a collimating lens, for example. The optical fiber 202 guides and propagates the light of the light source 10 to the optical fiber cantilever for scanning and exiting. The actuator 203 may be a piezoelectric actuator, an electrostatic actuator, an electromagnetic actuator, or a MEMS (Micro-Electro-Mechanical System) actuator, and the actuator is mainly described as the piezoelectric actuator herein. The actuator 203 can vibrate in multiple directions under the driving signal, thereby driving the fiber cantilever to perform two-dimensional scanning. For example, the actuator 203 may include a first actuating portion and a second actuating portion connected to the first actuating portion; under the action of a driving signal, the first actuating part vibrates in the first direction, the second actuating part vibrates in the second direction, the optical fiber cantilever sweeps in a synthetic mode of the first direction and the second direction, and the driving frequency corresponding to the first actuating part is smaller than or equal to that of the second actuating part; wherein the first direction may be a Y-axis direction and the second direction may be an X-axis direction.

Of course, referring to fig. 2, the fiber scanner further includes a housing 204, and the housing 204 is a vacuum environment to reduce the interference when the fiber cantilever vibrates. The light detector 30 may be disposed inside or outside the housing 204, and the embodiment of the invention is not limited in particular. Meanwhile, the fiber scanner may further include a projection objective 205, also called a lens group, which may be used to image the scanning surface of the end of the fiber cantilever onto a projection surface (such as a projection curtain) corresponding to the fiber scanning. The projection objective 205 may be located within the housing near the exit end of the fiber optic scanner, and may be located before or after the optical detector 30 relative to the scanner in the scanner's exit optical path. Preferably, the light detector 30 is arranged inside the housing 204 of the fiber scanner, for example between the fiber cantilever end and the projection objective 205, to improve the uniformity of the overall structure.

(2) The scanner 20 is a MEMS scanner.

The MEMS galvanometer is a key device for laser scanning, and can make simple harmonic oscillation along two directions (such as X-axis direction and Y-axis direction), and when making resonance motion, a Lissajous (Lissajous) graph is generated, i.e. a synthetic track of two sinusoidal oscillations along mutually perpendicular directions. Thus, the structure of the laser scanning projection device can refer to fig. 3. In fig. 3, image light (indicated by arrows) generated by the light source 10 is reflected by the scanning mirror of the MEMS scanner and is transmitted by the light detector 30, and then is projected on the projection carrier to form a projection image.

In practical applications, when the whole laser scanning projection apparatus is started, the motion state of the scanner 20 may be detected, and the light source 10 may be started again under the condition that the scanner 20 is determined to be swinging.

The optical detector 30 is located on the outgoing optical path of the scanner 20, and is configured to transmit all the scanning light emitted from the scanner 20, and at the same time, detect the light energy of the light incident on the target surface, where the light energy is the integral of the power in a preset time period (e.g., time t 1), and convert the change of the light energy into a corresponding electrical signal (e.g., current signal), where the value of the electrical signal is the amount of power accumulated in the time t1 of the detected scanning light. Preferably, the light detector 30 may be a transmission type photodetector, which transmits all the scanning light emitted from the scanner 20, so that the scanning light is transmitted to the corresponding projection carrier of the scanner 20 to form a projection image.

In practical applications, the light detector 30 is disposed near the light-emitting end of the fiber suspension arm, which is helpful to cover the whole scanning emergent field of view, so as to better detect and block light. The light scanned and emitted by the scanner 20 can be totally incident on the target surface of the light detector 30 and transmitted, and the area of the target surface can be preset according to parameters such as the distance between the light detector 30 and the scanner 20 and the size of the projected image, as long as the light scanner 30 can cover the whole scanning and emitting field of view of the scanner 20.

In the embodiment of the present invention, the light energy detected by the light detector 30 may be mainly used to determine whether the energy of the single-point transmission of the scanner 20 exceeds the energy value harmful to the human eye, and if the detected energy value approaches or reaches the energy value, the light source 10 may be turned off or the light path may be blocked.

Alternatively, the laser scanning projection device may monitor the current working status of the scanner 20, such as the projection brightness, the scanning status, etc., by analyzing the data, such as the optical power detected by the optical detector 30. For example, the laser scanning projection device can determine the intensity of the detected light power to determine whether the light intensity projected by the scanner 20 meets the requirement, i.e., determine whether the brightness of the emergent light of the scanner 20 meets the required display brightness, so as to quickly detect the condition that the projection brightness is greater than or less than the required display brightness, and improve the detection capability of the device.

Alternatively, the laser scanning projection device may store the data detected by the light detector 30, for example, in a local or cloud location, so as to be recalled when needed. For example, if the data is transmitted to the cloud, the data can be processed through the cloud server, and the cloud server can also feed back the processing and analyzing result to the scanner 20.

In another embodiment of the present invention, a controller may be further disposed in the laser scanning projection apparatus, and the controller is communicatively connected to the light source 10 and the light detector 30. The controller may be a component having data processing capabilities and may issue control signals to other components, for example, by communicating with other functional components by wired or wireless means. The controller may be a logical device or a separate physical device. The controller may be integrated into other functional components of the laser scanning projection device, such as the controller being integrated into the scanner 20; alternatively, the controller may also be a functional component that exists independently, and the embodiment of the present invention is not particularly limited in this respect.

In a laser scanning projection device, the controller may analyze the data detected by the light detector 30 to determine possible risks and/or malfunctions of the laser scanning projection device, which may help to improve the safety and reliability of the device. Generally, the light emitted from the scanner 20 is abnormal, including but not limited to two cases: firstly, the scanner 20 stops scanning when a fault occurs, scanning light rays are directly emitted, energy is gathered on a central shaft, and burning or even blindness is easily caused; the scanner 20 scans normally, but the energy of the light source 10 is abnormal, so that the energy of the light emitted in the preset time exceeds the damage threshold.

In the embodiment of the present invention, the controller receives the electrical signal representing the light energy output by the light detector 30, and can determine whether the scanner 20 is working normally, for example, whether the scanner 20 is stopped or not, according to the magnitude of the light energy (or the value of the electrical signal). In judgment, the following are included but not limited:

the first method is as follows: in the scanning projection process, firstly, judging whether the value of the light energy detected by the central area position of the target surface of the light detector 30 within the preset time is greater than or equal to a preset threshold value, wherein the preset threshold value can be set according to the safe energy value bearable by human eyes/skin within the preset time; if the light emitted by the scanner 20 is directly emitted at a single point in the central area of the target surface of the light detector 30, it can be determined that the scanner 20 has a fault during the scanning process. Alternatively, if it is determined that the optical energy at the position of the center region is smaller than the preset threshold within the preset time, the scanner 20 is considered to be in the normal operating state.

Of course, when it is determined that the scanner 20 has a failure, in order to clarify the failure of the scanner 20, for example, a failure such as stopping scanning by the scanner 20 or an abnormal output energy of the light source 10, it may be further determined whether the position of the edge area in the target surface is greater than the preset threshold or not, and whether the light energy detected within the preset time is also greater than the preset threshold; if the light intensity is smaller than the preset threshold value, the scanner 20 stops working, the light output by the scanner 20 only directly irradiates the central area of the target surface of the light detector 30, and at this time, the working of the scanner 20 can be stopped or the light intensity of the emergent light of the light source 10 can be reduced; or, if the light energy at the position of the edge detection area within the preset time is greater than or equal to the preset value, it indicates that the light energy of the light source 10 is abnormal, that is, the integrated energy of the light source 10 within the human eye integration time t1 exceeds the damage threshold, and at this time, the light source 10 may be turned off.

The first embodiment is further described by way of example with reference to the accompanying drawings:

for example, the RGB gray values of the light source 10 are (0 to 255), the RGB gray values projected in the device can be adjusted to be maximum (255, 255, 255), at this time, the scanner 20 scans the emergent pattern normally, the power integral value measured at the center of the target surface of the photodetector 30 is recorded within the time period t1, and the power integral value is used as the light energy threshold, that is, the preset threshold. When the scanner 20 emits light normally, the light detector 30 detects only one pulse in a time period t1, that is, a detection point of the light detector 30 is a pixel point; here, t1 is lower than the human eye integration time, and for example, t1 may be 30 ms.

When the light detector 30 works normally, if the power integral value of the power spectrum detected at the target surface center in the time period t1 is greater than the light energy threshold, it indicates that the light output of the scanner 20 is abnormal, and the light intensity needs to be turned off or reduced. The abnormal light emission of the scanner 20 may be direct light emission caused by the stop of the oscillation of the scanner 20, or may be excessive light emission energy caused by the abnormal light emission of the light source 10.

Fig. 4 is a schematic diagram of the power spectrum measured at the center of the target surface of the light detector 30 when the projected RGB gray-scale values are (255, 255, 255), and the scanner 20 scans normally. As can be seen from the graph, n pulses are received at the center of the target surface of the photodetector 30 in the time period t1, and the power integration value in the time period t1 is set as the threshold of the light energy.

Fig. 5 is a schematic diagram of a power spectrum measured at the center of the target surface of the optical detector 30 when the scanner 20 emits the modulation chart during normal operation. It can be seen that the scanned-out image resolution and pulse duration in fig. 5 are the same as in the embodiment of fig. 4, and that in this case the center of the target surface of the light detector 30 actually receives n pulses during the time period t 1. It will be appreciated that the power integration value for this case is necessarily less than the threshold value.

Fig. 6 is a power spectrum measured at the center of the target surface of the photodetector 30 when the modulated image is emitted when the scanner 20 is stopped, and the number of pulses received in the time period t1 is inevitably greater than n (assuming that m pulses are received) because the scanner 20 is stopped. When the power integration value is larger than the threshold value, the modulated light caused by the stop of the scanner 20 continuously irradiates the center of the target surface of the light detector 30, and measures for turning off or reducing the light intensity are taken.

In practical applications, when the method is adopted, a specific light in the light source 10 can be detected according to practical requirements. For example, the light source 10 includes an infrared light source, and if it is necessary to separately detect and determine infrared light, the light detector 30 and the power spectrum contrast may both detect and contrast infrared light. Of course, in the judgment mechanism of the first mode, it may also be directly judged whether the light detector 30 detects only one pulse within the time period t1 when t1 is 30ms (which is lower than the human eye integration time), that is, the detection point of the light detector 30 is a pixel point; if so, it indicates that the scanner 20 is operating properly.

The second method comprises the following steps: the predetermined detection determines the period of time during which light does not impinge on (i.e., is directed onto) the target surface of the light detector 30 during the scanning cycle of the scanner 20; therefore, during the operation of the scanner 20, the controller detects whether the scanning light generates an electrical signal in the scanning period of the scanner 20 and in the period of time when the light detector 30 is not directly illuminated, and if the electrical signal is detected, the operation of the scanner 20 is abnormal.

It should be noted that, under the condition of no conflict, the above-mentioned several manners may be used simultaneously or in combination to determine whether the scanner 20 is abnormal, as long as the corresponding conditions are met, the controller may determine that the scanner 20 is abnormal, and adopt the corresponding safety measures.

In practical detection, when the scanner 20 has a fault, such as a stop, the scanner 20 emits light at a single point, and since the radiation accumulation and the light pressure at a single point gradually increase, the light energy at the same position on the target surface of the light detector 30 is larger in the same time; when the scanner 20 emits a scanning light beam in a normal pattern, the light energy at the same position in the target surface of the light detector is smaller at the same time. In the embodiment of the present invention, when the light flux detected by the light detector 30 within the preset length of time is relatively large, and a single substantially stationary irradiation point is detected, the controller 30 may issue an instruction to control the light source 10 to turn off or reduce the brightness; when the light energy detected by the light detector 30 is small in the preset length of time, and a scan pattern is detected instead of a single light spot, the controller can send a command to control the light source 10 to emit light normally.

In practice, if the scanner 20 is stopped for a long time, the radiation accumulation and the light pressure of the single point of the direct and scattered light of the laser may cause some damage to the human eye, the skin and the projection carrier. In order to avoid the above risks, in another embodiment of the present invention, the laser scanning projection apparatus may further comprise a light source driver and/or a shutter.

The light source driver may be connected to the controller and the light source 10, and may turn off the light source 10 or reduce the driving voltage of the light source 10 according to an instruction of the controller, so as to enable the scanner 20 to be in a protection mode or a standby mode; when the laser scanning projection device determines that the scanner 20 works abnormally, the controller can turn off the laser or reduce the driving power of the laser through an electric control mode.

In practical applications, the controller may also be implemented by controlling a modulation system in the laser scanning projection apparatus when controlling the light output of the light source 10. The modulation system can adopt an internal modulation mode or an external modulation mode; the modulation system adopting the internal modulation mode mainly comprises a laser, wherein the internal modulation is completed inside the Laser (LD), namely, the electrical and optical signal input of the laser is changed through a driving signal (current/voltage), so that the modulation mode of changing the light energy of the output laser according to the requirement is realized; the modulation system adopting the internal modulation mode comprises a laser and an external modulator (such as an optical modulator) connected with the laser, when the external modulation mode is carried out, the output light energy of the laser does not change (is constant or quasi-constant), the optical modulator is introduced into the subsequent light path of the laser, and the modulation mode that the optical signal emitted from the modulator meets the requirement is achieved by controlling the modulator.

Specifically, the controller in the laser scanning projection apparatus can adopt different control modes according to different modulation systems, including but not limited to the following cases:

case 1: when the laser scanning projection device adopts an internal modulation mode, the controller can operate through the internal modulation system. For example, when the light detector 30 detects a single substantially stationary point of illumination, the controller controls the light source 10 (laser) in the internal modulation system to emit zero or low intensity light energy; when a scan pattern is detected, the controller controls the internal modulation system to switch to the normal modulation mode.

Case 2: when the laser scanning projection device adopts an external modulation mode, an external modulation system (comprising an optical modulator) operates; when the light detector 30 detects a substantially stationary illumination point, the external modulation system causes zero or low intensity light energy of the light passing through the light modulator; when a scan pattern is detected, the external modulation system is switched to the normal modulation mode.

In addition, a shutter may be disposed in the light exit path of the scanner 20, adjacent to the location of the fiber optic cantilever. The shutter may be a movable light barrier (e.g., a blacked metal shutter), an iris (e.g., a projection objective with an adjustable aperture), or other optical devices, and may be disposed between the scanner 20 and the projection carrier corresponding to the scanner 20, for example, between the scanner 20 and the lens group, for blocking the projection light path of the scanner 20, so as to reduce the light energy projected onto the projection carrier and reduce or avoid damage to the object. When the laser scanning projection device determines that the scanner 20 works abnormally, the controller may control an optical device such as an iris and/or a metal shutter to block the projection light path in a mechanical control mode, for example, close the iris or reduce the clear aperture of the iris, and/or control the metal shutter to move/rotate to block the projection light path.

Further, the light detector 30 may continue to detect the emergent light, and if it is determined that the scanner 20 is oscillated again, for example, the power of the scanning light is determined to be in a fluctuating state for a certain period of time, the controller 40 may perform a corresponding recovery operation, for example, control the light source driver to turn on the light source 10 again or recover the driving power of the light source 10, or control an optical device such as an iris/metal shutter to open the projection light path.

In the following, the application scenario of the laser scanning projection apparatus in the embodiment of the present invention is further described by way of examples.

Scene one: the scanner 20 in the laser scanning projection apparatus is a fiber scanner.

In this scenario, the transmissive optical detector 30 is disposed on an exit light path of the optical fiber scanner, and light beams emitted from the optical fiber cantilever in the optical fiber scanner during the swinging process all penetrate through the optical detector 30 and then are projected onto a corresponding projection surface of the optical fiber scanner.

When the light detector 30 detects only one substantially stationary irradiation point, the laser scanning projection device can control the light source 10 to be turned off or to reduce the brightness; alternatively, the laser scanning projection apparatus may further control a light shielding plate (e.g., a movable light shielding plate or a projection objective with a variable aperture) to shield part or all of the light path, so that the light will not irradiate on the external object; when the light detector detects a scanning pattern instead of a light spot, the laser scanning projection device can send out an instruction to control the light source to cancel the state of switching off the light source or reducing the brightness, and the light is emitted normally.

Scene two 2: the scanner 20 in a laser scanning projection device is a MEMS scanner.

In the scene, light emitted by the light source irradiates on the MEMS galvanometer, the optical detector 30 is arranged on a projection scanning light path of the MEMS galvanometer, and the light emitted by the MEMS galvanometer after rotating firstly penetrates through the optical detector 30 and then irradiates on a projection surface to form a projection image.

When the light detector only detects one light spot, the laser scanning projection device can control the light source 10 to be switched off or reduce the brightness through a light source driver or a modulation system and the like; or if the light-emitting path of the MEMS galvanometer is provided with a movable light shielding plate close to the position of the MEMS galvanometer, the light shielding plate can be controlled to shield the light path so that light cannot irradiate on an external object; when the light detector 30 detects a scanning pattern instead of a light spot, the laser scanning projection device sends an instruction to control the light source 10 to cancel the state of turning off the light source or reducing the brightness, and light is emitted normally.

In the embodiment of the invention, the laser scanning projection device can cover the whole scanning emergent view field of the scanner through the optical detector 30 arranged on the emergent light path of the scanner, and detect the light energy of the scanning light emitted by the scanner, so that in the scanning projection process of the laser scanning projection device, the light energy condition of the scanning light emitted by the scanner 20 can be monitored in real time through the optical detector 30, and the safety of the laser scanning projection device is improved.

Based on the same inventive concept, as shown in fig. 7, an embodiment of the present invention further provides a detection method, which can be used in the foregoing laser scanning projection apparatus. The detection method comprises the following steps:

s11: the laser scanning projection device controls a light source to emit image light corresponding to an image to be displayed, and the image light is scanned and emitted by a scanner 20 to form scanning light;

s12: the laser scanning projection device transmits the scanning light through the optical detector 30 and detects the light energy of the scanning light, and the value of the light energy is used for representing the power integral of the scanning light within the preset time.

In the embodiment of the invention, when the laser scanning projection device scans and emits the scanning optical fiber corresponding to the image to be displayed, the scanning light is transmitted through the optical detector 30, and the light energy of the scanning light is detected, so that the light energy condition of the scanning light emitted by the scanner 20 can be monitored in real time through the optical detector 30 under the condition of not influencing the light power, and the safety of the laser scanning projection device is improved.

Please refer to fig. 1 to 6 and related descriptions for the structure and the working principle of the laser scanning projection apparatus, which are not described herein again.

After S12, the laser scanning and projecting device can further determine whether the detected light energy value is greater than a preset threshold value. Wherein, the light energy can be the power integral value measured by the light detector 30 at the target surface center in the detection process within the time t 1; the preset threshold may be preset according to a safe energy value that the human eye/skin can bear within a preset time, for example, when the scanner 20 scans the emergent light normally, the power integration value measured by the target surface center of the photodetector 30 is recorded within the human eye safe integration time t1 as the preset threshold.

If it is determined that the value of the light energy is greater than the preset threshold, it indicates that the laser scanning projection apparatus is working abnormally, for example, it may be that the scanner 20 is stopped or the energy of the light emitted from the light source 10 is abnormal, and at this time, the light emitted from the scanner 20 may be controlled, for example, the light source 10 is turned off or the driving voltage of the light source 10 is reduced, or the projection light path of the scanner 20 is blocked. The related determination methods may refer to the foregoing various methods and corresponding processing measures, which are not described herein again.

Based on the same inventive concept, the embodiment of the present invention further provides a laser scanning projection apparatus, which includes the aforementioned laser scanning projection device, and the optical detector 30 disposed on the emergent light path of the scanner 20 can monitor the working data during scanning in real time during the scanning projection process, which is helpful for improving the safety and reliability of the apparatus.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to encompass such modifications and variations.

Claims

1. The utility model provides a laser scanning projection arrangement which characterized in that, includes light source, scanner and optical detector, the light source is used for the image light of emergent image of waiting to display, the scanner be used for with image light scanning outgoing forms scanning light, optical detector sets up on the outgoing light path of scanner, be used for detecting scanning light's light energy, and the transmission scanning light.

2. The laser scanning projection apparatus of claim 1, further comprising a controller connected to the light detector for determining whether the value of the light energy is greater than a preset threshold, and controlling the light emitted from the scanner when it is determined that the value of the light energy is greater than the preset threshold.

3. The laser scanning projection apparatus of claim 2, wherein the laser scanning projection apparatus further comprises:

4. A laser projection device as claimed in any one of claims 1 to 3, wherein the light detector is a transmissive photodetector.

5. A laser scanning projection device as claimed in claim 4, wherein said scanner is a fiber optic scanner or a MEMS scanner.

6. The laser scanning projection apparatus of claim 5, wherein if the scanner is a fiber scanner, the fiber scanner includes an actuator and a fiber fixed on the actuator, an end of the fiber beyond the actuator forms a fiber cantilever, and the actuator drives the fiber cantilever to vibrate under the action of a driving signal.

7. The laser scanning projection device of claim 6, wherein the fiber scanner further comprises a projection objective lens disposed on an exit light path of the fiber scanner for imaging a scanning surface at the end of the fiber suspension arm onto a projection surface corresponding to the fiber scanning.

8. A detection method is applied to a laser scanning projection device, the laser scanning projection device comprises a light source, a scanner and a light detector, the light detector is positioned on an emergent light path of the scanner, and the detection method is characterized by comprising the following steps:

9. The detection method of claim 8, wherein after detecting the light energy of the scanning light line, the method further comprises:

10. A laser scanning projection device, characterized in that it comprises a laser scanning projection arrangement according to any of claims 1-9.