Light source device with high brightness

Abstract

A light source device is disclosed. The light source device comprises: a primary condensing lens; a secondary condensing lens having the same optical axis as the primary condensing lens and having a smaller diameter than the primary condensing lens; a plurality of laser light sources that outputs light parallel to an optical axis; and a fluorescent plate. The primary condensing lens refracts light outputted from the plurality of laser light sources to condense the outputted light to a region of the fluorescent plate, and, when the light incident on the region of the fluorescent plate is reflected from the fluorescent plate, causes the reflected light to be refracted to then be incident on the secondary condensing lens in parallel to the optical axis. The secondary condensing lens refracts the light incident on the secondary condensing lens and condenses the light at one point.

Description

High-brightness light source device

[0001] The present disclosure relates to a high-brightness light source device, and more particularly, to a light source device that focuses the output of at least one laser light source and / or LED light source to concentrate strong light on a very small area.

[0002] A microscope is a tool that uses lenses to magnify and view very small objects. Since the higher the magnification, the darker the image tends to be, in order to obtain a bright image, light must be focused on the object and bright light must be applied.

[0003] In the past, light-collecting devices using arc lamps such as halogen or metal halide and reflective mirrors were mainly used as illumination devices for microscopes, but there were problems with the low efficiency and heat generation of arc lamps.

[0004] As the efficiency of semiconductor light-emitting devices improves, LEDs (Light Emitting Diodes) are increasingly being adopted as microscope light sources. In the semiconductor and machine vision inspection fields, inspection targets are becoming increasingly small, reaching a few micrometers in size, requiring high-magnification microscope optics to inspect them.

[0005] In particular, capturing images of moving objects requires extremely high-brightness lighting for extremely short exposure times, typically within microseconds. Even LEDs cannot produce the required amount of light to capture moving objects, so strobe-style light sources using arc lamps are primarily used.

[0006] However, due to the nature of arc lamps, which fluctuate in brightness and have a long lifespan when shooting with an arc lamp in strobe mode, there is a continuous demand for a more stable and long-lasting light source.

[0007] Recently, a technology has been introduced to replace arc lamps by using a high-power blue laser diode to irradiate laser light generated from a light source onto a very narrow area of ​​a fluorescent substance and generate a wide spectrum of light generated by excitation of the fluorescent substance.

[0008] The present disclosure provides a high-brightness light source device that collects light output from a plurality of light sources using a plurality of collecting lenses.

[0009] The purposes of the present disclosure are not limited to those mentioned above, and other purposes and advantages of the present disclosure not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present disclosure. Furthermore, it will be readily apparent that the purposes and advantages of the present disclosure can be realized by the means and combinations thereof set forth in the claims.

[0010] According to one embodiment of the present disclosure, a light source device includes a primary condenser lens, a secondary condenser lens having the same optical axis as the primary condenser lens and a smaller diameter than the primary condenser lens, a plurality of laser light sources outputting light parallel to the optical axis, and a fluorescent plate. The primary condenser lens refracts light output from the plurality of laser light sources to cause it to enter a region of the fluorescent plate, and when the light incident on the region of the fluorescent plate is reflected from the fluorescent plate, the reflected light refracts to cause it to enter the secondary condenser lens parallel to the optical axis, and the secondary condenser lens refracts the light incident on the secondary condenser lens and focuses it to a point.

[0011] The light source device further includes an LED (Light Emitting Diode) light source that is positioned adjacent to the fluorescent plate and outputs light in the direction of the fluorescent plate. In this case, the primary condenser lens refracts the light output from the LED light source and transmitted through the fluorescent plate so that the light becomes parallel to the optical axis, and the secondary condenser lens can further refract the light output from the LED light source and refracted through the primary condenser lens and focus it to the point.

[0012] The light source device may further include a mirror disposed adjacent to the fluorescent plate and disposed in an opposite direction of the primary condenser lens with respect to the fluorescent plate.

[0013] The plurality of laser light sources may be arranged on a plane perpendicular to the optical axis so that the straight-line distances from the optical axis are equal to each other. In addition, light output from the plurality of laser light sources may pass through a plane perpendicular to the optical axis and including the center point of the secondary condenser lens without being incident on the secondary condenser lens, and then be incident on the primary condenser lens.

[0014] The above fluorescent plate can, when light of a first wavelength is incident on it, convert the wavelength of the incident light into a second wavelength longer than the first wavelength and output the converted light.

[0015] Meanwhile, light output from the plurality of laser light sources may be incident on a first region having a long distance from the optical axis among the entire area of ​​the primary condenser lens, and light reflected from the fluorescent plate may be incident on a second region having a short distance from the optical axis among the entire area of ​​the primary condenser lens.

[0016] A system according to one embodiment of the present disclosure includes a light source device, a lighting control device for controlling the blinking of the plurality of laser light sources constituting the light source device, and a camera for photographing the moving inspection object, the camera facing the light source device with at least a portion of the movement path of the inspection object interposed therebetween. The light source device includes a primary condenser lens, a secondary condenser lens having the same optical axis as the primary condenser lens and a smaller aperture than the primary condenser lens, a plurality of laser light sources for outputting light parallel to the optical axis, and a fluorescent plate.

[0017] The system may further include a processing device that analyzes an image captured by the camera to obtain drop information including at least one of a velocity, volume, and trajectory of an ink droplet. Here, the processing device may communicate with an ink output device that outputs the ink liquid, and provide feedback related to the output of the ink liquid based on the drop information.

[0018] At this time, the processing device can calculate the sharpness of the image and, based on the calculated sharpness, adjust the pulse duration of the lighting control device that drives the plurality of laser light sources constituting the light source device.

[0019] In addition, the processing device may store the value of sharpness acquired for each pulse duration value, and drive a plurality of laser light sources constituting the light source device based on the stored pulse duration so as to match a target value of sharpness set according to a user input. Meanwhile, the plurality of laser light sources may be arranged on a plane perpendicular to the optical axis so that the straight-line distances from the optical axis are equal to each other, and may be divided into a plurality of groups, and each group may be composed of a pair of laser light sources positioned opposite each other based on the optical axis, and an average of the positions of the laser light sources constituting each group may match the position of the optical axis. At this time, the processing device may acquire the sharpness of an image captured by the camera while the plurality of laser light sources are driven based on the pulse duration stored so as to match the target value of the sharpness, and compare the acquired sharpness with the target value, and if the comparison result shows a difference of a predetermined value or more, sequentially drive the plurality of groups, respectively acquire the sharpness of an image captured while each group is driven, and identify at least one group having a problem based on the acquired sharpness for each group, and provide a message notifying that the identified group has a problem.

[0020] The light source device according to the present disclosure has the advantage of being able to provide high-brightness light in a narrow or extremely small area based on focusing the output light of one or more laser light sources and LED light sources.

[0021] A system including a light source device according to the present disclosure has the advantage of being able to perform precise image analysis by high-speed photographing of an object to be inspected (e.g., ink droplet) based on high-brightness strobe control.

[0022] FIG. 1 is a block diagram illustrating the configuration of a light source device according to an embodiment of the present disclosure;

[0023] FIG. 2 is a drawing for explaining the arrangement of each component included in a light source device according to one embodiment of the present disclosure;

[0024] FIG. 3 is a flowchart for explaining the path of light output from a laser light source of a light source device according to one embodiment of the present disclosure;

[0025] FIG. 4 is a drawing for explaining the arrangement of each component of a light source device including an LED light source according to one embodiment of the present disclosure;

[0026] FIG. 5 is a drawing for explaining an operation in which an LED light source according to one embodiment of the present disclosure drives a plurality of laser light sources by group;

[0027] FIG. 6 is a drawing for explaining the configuration of a system for monitoring ink drops, including a light source device according to one embodiment of the present disclosure;

[0028] FIG. 7a is a drawing for explaining the structure of a system according to one embodiment of the present disclosure;

[0029] FIG. 7b is a drawing for explaining the structure of a system according to one embodiment of the present disclosure, and

[0030] FIG. 8 is a drawing for explaining the results of capturing different shapes of ink droplets depending on the cycle in which a system according to one embodiment of the present disclosure drives a laser light source.

[0031] Before describing the present disclosure in detail, the description method of the specification and drawings will be described.

[0032] First, the terms used in this specification and claims are general terms selected based on their functions in the various embodiments of the present disclosure. However, these terms may vary depending on the intentions of those skilled in the art, legal or technical interpretations, and the emergence of new technologies. Furthermore, some terms may have been arbitrarily selected by the applicant. These terms may be interpreted according to the meanings defined in this specification. In the absence of a specific definition, they may be interpreted based on the overall content of this specification and common technical knowledge in the relevant field.

[0033] Additionally, the same reference numbers or symbols in each drawing attached to this specification represent parts or components that perform substantially the same functions. For convenience of explanation and understanding, the same reference numbers or symbols are used in different embodiments. In other words, even if components with the same reference numbers are all depicted in multiple drawings, the multiple drawings do not necessarily represent a single embodiment.

[0034] Additionally, terms including ordinal numbers, such as "first," "second," etc., may be used in this specification and claims to distinguish between components. These ordinal numbers are used to distinguish identical or similar components from each other, and the use of these ordinal numbers should not be interpreted in a limited manner. For example, components associated with these ordinals should not be restricted in their order of use or arrangement by their numbers. If necessary, each ordinal number may be used interchangeably.

[0035] In this specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "comprise" or "consist of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0036] In the embodiments of the present disclosure, terms such as "module," "unit," "part," etc. are terms used to refer to components that perform at least one function or operation, and such components may be implemented as hardware or software, or a combination of hardware and software. In addition, a plurality of "modules," "units," "parts," etc. may be integrated into at least one module or chip and implemented as at least one processor, except in cases where each needs to be implemented as a separate, specific hardware.

[0037] Additionally, in the embodiments of the present disclosure, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection through another medium. Furthermore, unless specifically stated otherwise, the statement that a part includes a certain component does not exclude other components, but rather implies that other components may be included.

[0038] FIG. 1 is a block diagram illustrating the configuration of a light source device according to an embodiment of the present disclosure.

[0039] Referring to FIG. 1, the light source device (100) may include one or more laser light sources (110), a primary condenser lens (120-1), a secondary condenser lens (120-2), a fluorescent plate (130), etc.

[0040] The light source device (100) can be included in microscope equipment, semiconductor inspection equipment, cameras, magnifying glasses, etc., and can also be used in various equipment for providing high-brightness light to a microscopic area.

[0041] The laser light source (110) may include at least one laser diode, a collimator / lens (e.g., collimator lens) for generating parallel light, and at least one driving unit for supplying current to the laser diode.

[0042] A laser diode can generate laser light using a forward-biased semiconductor junction as an active medium, and may be composed of, but is not limited to, GaAs, for example.

[0043] The light source device (100) may include a plurality of laser light sources. In this case, each of the plurality of laser light sources may output light that travels in a direction parallel to each other.

[0044] The primary condenser lens (120-1) and the secondary condenser lens (120-2) correspond to condenser lenses sequentially arranged on the same optical axis.

[0045] The primary condenser lens (120-1) and the secondary condenser lens (120-2) may each include one or more lenses, and may include a plano-convex lens, a biconvex lens, etc.

[0046] The diameter of the primary condenser lens (120-1) may be larger than the diameter of the secondary condenser lens (120-2).

[0047] The (laser) light output from the above-described laser light source (110) can travel in a direction parallel to the optical axis of the focusing lenses (120-1, 2).

[0048] When the light source device (100) includes a plurality of laser light sources, the straight-line distances of each of the plurality of laser light sources with respect to the above-described optical axis may be the same, and the light output from the plurality of laser light sources may travel in a direction parallel to the above-described optical axis.

[0049] A fluorescent plate (130) means a plate containing a fluorescent material on its surface.

[0050] The fluorescent plate may include a substrate, a reflector, a fluorescent film, and the like. For example, the substrate may be composed of a plastic plate, and the reflector may be composed of a conductive mesh, a thin film, and / or a dielectric. In addition, the fluorescent film may be coated with Ce:YAG (Yttrium / Aluminum / Garnet coated with Cerium) or a silicate fluorescent material. However, the configuration of the fluorescent plate is not limited to the examples described above, and may have a configuration according to various conventional technologies.

[0051] The fluorescent plate (130) can absorb incident high-energy light and convert it into lower-energy light. Specifically, the fluorescent plate (130) can convert incident short-wavelength light into long-wavelength light and reflect or transmit it.

[0052] The fluorescent plate (130) may include a mirror on the rear side or may be installed adjacent to the LED light source. Alternatively, the fluorescent plate (130) may be implemented to be included in the LED light source.

[0053] The arrangement of the above-described components and the path of light in the light source device (100) are explained below with reference to FIGS. 2 and 3.

[0054] Referring to FIG. 2, the primary condenser lens (120-1) and the secondary condenser lens (120-2) can be sequentially arranged on the same optical axis.

[0055] In addition, a plurality of laser light sources (110-1, 2) can be arranged on a plane perpendicular to the optical axis so that the straight-line distance from the optical axis is equal to each other. Here, the straight-line distance from the optical axis can be greater than half the diameter of the secondary condenser lens (120-2).

[0056] Referring to FIG. 2, the fluorescent plate (130) may also be placed on the optical axis described above, and specifically, may be placed in the order of the secondary condenser lens (120-2), the primary condenser lens (120-1), and the fluorescent plate (130).

[0057] Light output from multiple laser light sources (110-1, 2) can travel in a direction parallel to the optical axis (S310 in FIG. 3).

[0058] At this time, the output light can be incident on the primary condenser lens (120-1) without passing through the secondary condenser lens (120-2).

[0059] Specifically, light output from multiple laser light sources (110-1, 2) can pass through a plane that is perpendicular to the optical axis and includes the center point of the secondary condenser lens (120-2) without being incident on the secondary condenser lens. In addition, light passing through the plane can be incident on the primary condenser lens (120-1).

[0060] That is, since the aperture of the primary condenser lens (120-1) is larger than the aperture of the secondary condenser lens (120-2), light output from multiple laser light sources (110-1, 2) can be directly incident on the primary condenser lens (120-1).

[0061] In this case, the primary condenser lens (120-1) can refract light output from multiple laser light sources and focus the output light onto one area of ​​the fluorescent plate (130) (S320).

[0062] Here, the fluorescent plate (130) can reflect light incident through the primary condenser lens (120-1) (S330). For this purpose, at least one configuration for reflection may be included on the rear surface of the fluorescent plate (130).

[0063] In one embodiment, a mirror may be included in the light source device (100) and is positioned adjacent to the fluorescent plate (130) and positioned in the opposite direction (rear) of the primary condenser lens with respect to the fluorescent plate.

[0064] Alternatively, at least one LED diode may be placed adjacent to the rear of the fluorescent plate (130).

[0065] The fluorescent plate (130) can reflect the incident light by converting the wavelength of the incident light into a relatively longer wavelength (short wavelength -> long wavelength), and the long wavelength light reflected from the fluorescent plate (130) can be incident again on the first condenser lens (120-1).

[0066] Here, referring to FIG. 2, the light output from the plurality of laser light sources (110-1, 2) may be incident on an area (outer) that is relatively far from the optical axis among the entire area of ​​the primary condenser lens (120-1), whereas the light reflected from the fluorescent plate (130) may be incident on an area (inner) that is relatively close to the optical axis among the entire area of ​​the primary condenser lens (120-1).

[0067] In addition, the first condenser lens (120-1) can refract the light (long wavelength) reflected from the fluorescent plate (130) and re-incident (S340). In this case, the light refracted again through the first condenser lens (120-1) can be incident on the secondary condenser lens (120-2) in a direction parallel to the optical axis.

[0068] And, the secondary condenser lens (120-2) can refract the incident light and focus it to one point (S350).

[0069] According to the above-described embodiment, light output from multiple laser light sources (110-1, 2) is focused to one point, so that high-brightness light can be provided to a narrow area.

[0070] Meanwhile, although the above-described FIG. 2 illustrates a case in which there are two laser light sources, it is of course possible to additionally provide one or more laser light sources having the same shortest distance from the optical axis.

[0071] Meanwhile, FIG. 4 is a drawing for explaining the arrangement of each component of a light source device including an LED light source according to one embodiment of the present disclosure.

[0072] Referring to FIG. 4, the light source device (100) may further include an LED light source (140), a heat sink (150), etc. in addition to the above-described configurations.

[0073] The LED light source (140) can be placed adjacent to the fluorescent plate (130) and can be positioned in the opposite direction of the primary light collecting lens (120-1) with respect to the fluorescent plate (130).

[0074] The LED light source (140) may include at least one LED (Light Emitting Diode), a driving unit for supplying current to the LED, etc. Alternatively, the LED light source (140) may include at least one micro LED, OLED (Organic LED), etc.

[0075] The LED light source (140) may include, for example, at least one LED for emitting blue light. In this case, the output blue light may be converted into white light through a fluorescent plate (130) coated with a fluorescent material (e.g., yellow). Alternatively, the LED light source (140) may include R / G / B LEDs for emitting white light, respectively. However, the present invention is not limited to the above-described embodiment.

[0076] The LED light source (140) can output light in the direction of the fluorescent plate (in the direction of the primary condenser lens (120-1)).

[0077] In this case, light output from the LED light source (140) can pass through the fluorescent plate (130) and enter the primary light collecting lens (120-1).

[0078] Here, light incident on the fluorescent plate (130) can be incident on the primary condenser lens (120-1) with a longer wavelength.

[0079] The primary condenser lens (120-1) can refract light output from an LED light source (140) and transmitted through a fluorescent plate (130) so that the light becomes parallel to the optical axis. As a result, the refracted light can be incident on the secondary condenser lens (120-2).

[0080] In this case, the secondary focusing lens (120-2) can additionally refract the incident light and focus it to the aforementioned point.

[0081] As a result, light output from multiple laser light sources (110-1, 2) and light output from an LED light source (140) are all gathered at one point, so that high-brightness light can be provided.

[0082] The heat sink (150) is configured to release heat from the LED light source (140) or fluorescent plate, and as shown in FIG. 4, it may be provided to contact the rear surface of the LED light source (140).

[0083] The heat sink (150) may be made of metal, plastic, carbon, ceramic, or other polymer materials with excellent heat conductivity, but is not limited thereto.

[0084] Meanwhile, although not shown, the light source device (100) may include at least one control unit for controlling the operation of the above-described plurality of laser light sources (110-1, 2) and LED light sources (140).

[0085] The control unit may include at least one processor or control circuit.

[0086] For example, the control unit can drive multiple laser light sources (110-1, 2) and LED light sources (140) according to a user input that operates at least one switch / button provided in the light source device (100). However, the user input can be received in various other forms, and the user input can also be received through at least one external device capable of wired or wireless communication with the light source device (100).

[0087] The control unit can also control the intensity (brightness) of light focused on the above-described point in stages.

[0088] In this case, the control unit can adjust the number of laser light sources that output light for each brightness level differently.

[0089] As a specific example, when a user input is received to provide light of level 1 brightness, the control unit can drive an LED light source (140) and one laser light source (110-1) to output light.

[0090] When a user input for providing light of a two-level brightness is received, the control unit can drive the LED light source (140) and two laser light sources (110-1, 2) to output light.

[0091] Additionally, the control unit can divide multiple laser light sources into multiple groups and drive them according to brightness levels.

[0092] In relation to this, Fig. 5 illustrates a top view of a plurality of laser light sources arranged based on the optical axis.

[0093] Referring to FIG. 5, the light source device (100) may include a plurality of laser light sources (110-1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) positioned at the same straight-line distance based on the optical axis.

[0094] Multiple laser sources (110-1, 2, 3, …) can be divided into three groups.

[0095] The first group consists of laser light sources (110-1, 2, 3, 4), the second group consists of laser light sources (110-5, 6, 7, 8), and the third group consists of laser light sources (110-9, 10, 11, 12).

[0096] Referring to FIG. 5, each group described above may be composed of a pair of laser light sources positioned opposite each other with respect to the optical axis. Furthermore, the average (center of gravity) of the positions of the laser light sources constituting each group matches the position of the optical axis.

[0097] In this case, when a user input for providing light of level 1 brightness is received, the control unit can drive the LED light source (140) and the first group (110-1, 2, 3, 4) to output light.

[0098] When a user input for providing light of a two-level brightness is received, the control unit can drive the LED light source (140), the first group (110-1, 2, 3, 4), and the second group (110-5, 6, 7, 8) to output light.

[0099] When a user input for providing light of three levels of brightness is received, the control unit can induce the LED light source (140), the first group (110-1, 2, 3, 4), the second group (110-5, 6, 7, 8), and the third group (110-9, 10, 11, 12) to output light.

[0100] In this way, when the light output is added for each group unit composed of laser light sources facing each other with respect to the optical axis as the standard, there is an advantage in that the uniformity of the light provided by the light source device (100) can be maintained relatively consistently.

[0101] Meanwhile, the control unit can sequentially drive each group according to the time at which each group described above was driven.

[0102] For example, if the first group (110-1, 2, 3, 4) is continuously driven for a critical time or longer, the control unit can deactivate the first group and drive the second group (110-5, 6, 7, 8) to output light.

[0103] Here, after the second group (110-5, 6, 7, 8) is also continuously driven for a critical time or longer, the control unit can deactivate the first and second groups and drive the third group (110-9, 10, 11, 12) to output light.

[0104] Alternatively, the control unit may divide the entire time during which the light source device (100) provides light into multiple time intervals and drive one group for each divided time interval.

[0105] For example, during the first time interval, the first group (110-1, 2, 3, 4) is driven, during the second time interval, the second group (110-5, 6, 7, 8) is driven, during the third time interval, the third group (110-9, 10, 11, 12) is driven, and so on, the driving of each group can be sequentially activated.

[0106] This provides management advantages, as the laser light source in each group is guaranteed a rest period, thereby delaying the aging of the laser light source. Furthermore, inspection and maintenance of each laser light source can be performed during the rest period.

[0107] Meanwhile, various visual inspection systems can be implemented based on the above-described light source device (100).

[0108] FIG. 6 is a drawing for explaining the configuration of a system including the light source device (100) described above according to one embodiment of the present disclosure.

[0109] The system (1000) may correspond to various systems for inspecting / monitoring the surface of fine particles or fine areas in real time. For example, the system (1000) may be utilized for, but is not limited to, measuring ink droplets of an inkjet, patterning processes of semiconductors, and external inspection of semiconductors.

[0110] Referring to FIG. 6, the system (1000) may include a light source device (100), a lighting control device (200), a camera (300), etc. according to at least one of the various embodiments described above.

[0111] The lighting control device (200) is a device for controlling the light output (e.g., blinking) of each of the plurality of laser light sources constituting the light source device (100). To this end, the lighting control device (200) may include at least one power supply means, and for example, the lighting control device (200) may control the on / off of the light output elements by repeatedly and rapidly switching (on / off) the power supply to the light output elements constituting each of the laser light sources. To this end, the lighting control device (200) may include at least one switching unit.

[0112] The switching unit can selectively cut off the power (electricity) supplied to the lighting unit (120) by controlling the switching element. The switching element can be implemented with various elements such as a BJT (Bipolar Junction Transistor), FET (Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), thyristor, TRIAC (Triode AC switch), and DIAC (Diode AC switch), but is not limited thereto.

[0113] For example, the lighting control device (200) can control the pulse duration in units of 0.1 μs, but is not limited thereto.

[0114] To minimize the rising delay caused by the coil component, the length of the lighting cable connecting each laser light source of the lighting control device (200) and the light source device (100) may be designed to not exceed 20 cm. As a result, more precise strobe / pulse control is possible.

[0115] The camera (300) is configured to photograph an inspection target (e.g., a falling ink droplet). The camera (110) may be implemented as an RGB camera, a TOF (Time of Flight) camera, etc.

[0116] The camera (110) may be implemented as a high-speed camera or an ultra-high-speed camera for photographing a subject (ultrasonic vibrating knife) according to a preset cycle (e.g., 1 / 100 second, 1 / 200 second, 1 / 300 second, etc.). The shorter the cycle and the faster the continuous photographing speed, the more suitable it may be for the inspection system (100) according to the present disclosure. The camera (110) may include at least one image sensor and a lens for adjusting the path of light to photograph a specific point or a specific range.

[0117] In one embodiment, the camera (300) may be formed at a position facing the light source device (100) with at least a portion of the movement path of the inspection target (e.g., the drop path of the ink droplet) between them.

[0118] FIG. 7A is a diagram for explaining the structure of a system according to an embodiment of the present disclosure. Referring to FIG. 7A, a lighting control device (200) may include a strobe controller, a pulse generator, etc. The strobe controller may include at least one switching element for controlling the blinking of the light output elements constituting each laser light source of the light source device (100). The pulse generator is configured to generate / change a pulse duration corresponding to the ON / OFF cycle of the switching element. Referring to FIG. 7A, a camera (300) may capture an ink droplet falling through a shooting range to obtain an image.

[0119] FIG. 7b is a diagram illustrating the structure of a system according to one embodiment of the present disclosure. FIG. 7b illustrates in more detail the positional relationship between an ink output device that outputs ink droplets and the system (1000).

[0120] Referring to FIG. 7b, the ink output device may include a Syringe Pump that provides a driving force for outputting ink droplets, a Hemispherical Nozzle for outputting ink droplets, etc.

[0121] For example, the ink output device can output ink droplets falling at a speed of 5 to 15 m / s, preferably 10 m / s, but is not limited thereto. For example, the ink ejection cycle of the ink output device can be 1 ms (1 kHz), but is not limited thereto.

[0122] At this time, the camera (300) of the system (1000) can capture multiple images by photographing ink droplets in real time within a lighting environment provided by the light source device (100).

[0123] Meanwhile, referring to the above-described FIG. 6, the system (1000) may further include a processing device (400) for analyzing an image captured by a camera (300) and controlling at least one of the lighting control device (200) and the camera (300). The processing device (400) controls the ink output of the ink output device (e.g., output intensity, output size, unit output amount, etc.).

[0124] The processing device (400) may include at least one memory, processor, etc., and may be connected to the various devices / hardware configurations described above via wired / wireless communication.

[0125] In one embodiment, the processing device (400) may analyze an image captured by the camera (300) to obtain drop information including at least one of the speed, volume, and trajectory of the ink droplet. At this time, the processing device (400) may provide feedback related to the output of the ink droplet based on the drop information, and the output strength of the pump, etc. of the ink output device that has received the feedback may be adjusted.

[0126] As the light source device (100) according to the various embodiments described above is utilized, the amount of light providing the lighting environment can be greatly increased, and as a result, the quality of the image for the inspection target (e.g., ink droplet) can also be improved, so that the inspection can proceed smoothly.

[0127] Meanwhile, FIG. 8 is a drawing for explaining the results of photographing ink droplets in different shapes depending on the cycle in which the system according to one embodiment of the present disclosure drives the laser light source. Referring to FIG. 8, when the pulse duration of the lighting control device (200) is 1 μs, the ink droplets are photographed relatively blurry (large blur), whereas when the pulse duration is 250 ns, the ink droplets are photographed clearly.

[0128] Accordingly, the lighting control device (200) can drive the laser light sources of the light source device (100) based on a pulse duration of 300 ns or less, preferably 250 ns or less, but is not limited thereto.

[0129] In relation to this, as an example, the processing device (400) can calculate the sharpness of an image captured by the camera (300). Sharpness is a concept indicating the clarity of the outline of an object in an image.

[0130] Here, the processing device (400) can adjust the pulse duration of the lighting control device (200) that drives multiple laser light sources constituting the light source device (100) based on the calculated sharpness. For example, the pulse duration can be reduced as the sharpness decreases.

[0131] In one embodiment, the processing device (400) can monitor the sharpness of an image captured by the camera (300) at regular intervals. At this time, the sharpness can be extracted only for images that include one or more objects (e.g., ink droplets). Here, whether an ink droplet is included can be determined based on a measurement of a contrast value (e.g., an ink droplet is determined to be included if the contrast is above a certain value) or can be determined based on at least one object recognition model (e.g., CNN) for identifying an ink droplet.

[0132] Here, if the sharpness is below the threshold, the lighting control device (200) can reduce the pulse duration by a certain amount, and this process can be repeated until the sharpness is above the threshold.

[0133] Additionally, as an example, the processing device (400) can monitor the amount of change in sharpness during the step-by-step change in pulse duration.

[0134] At this time, the processing device (400) can store the sharpness values ​​obtained for each pulse duration value in at least one memory. In this regard, the processing device (400) can set a target value of sharpness according to a user input, and can drive a plurality of laser light sources based on the stored pulse duration so as to match the target value of sharpness.

[0135] Meanwhile, when driving multiple laser light sources based on the pulse duration stored to match the target value of sharpness, the processing device (400) can obtain the sharpness of the image captured by the actual camera (300) and compare it with the target value. If the obtained sharpness has a difference of a certain value or more from the target value, the processing device (400) can identify that a problem has occurred in at least one of the multiple laser light sources.

[0136] In this case, the processing device (400) can sequentially drive each group (the first group, the second group, and the third group) of the above-described FIG. 5 to obtain the sharpness of the image captured in a state in which each group is selectively driven. For example, the first sharpness of the image captured in a state in which only the first group is driven, the second sharpness of the image captured in a state in which only the second group is driven, and the third sharpness of the image captured in a state in which only the third group is driven can be calculated, respectively.

[0137] Here, the processing device (400) can compare the first to third sharpnesses and identify at least one of the first to third sharpnesses whose values ​​are different by a predetermined value or more. For example, if the value of the second sharpness is lower than the first and third sharpnesses by a predetermined value or more, the processing device (400) can identify that at least one of the second group of laser light sources corresponding to the second sharpness has a problem.

[0138] In this case, the processing device (400) may provide a message indicating that a problem has occurred in the second group.

[0139] To this end, the processing device (400) may include a display, a speaker, etc., and may output the corresponding message visually / audibly. Alternatively, the processing device (400) may be connected to at least one external device including a display and / or a speaker via wired / wireless communication to transmit the corresponding message. As a result, the user can identify a problem with at least one of the second group of laser light sources and perform an inspection.

[0140] Meanwhile, the various embodiments described above may be implemented by combining multiple embodiments as long as they do not conflict with each other.

[0141] Meanwhile, although the preferred embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above, and various modifications may be made by a person having ordinary skill in the art to which the present disclosure pertains without departing from the gist of the present disclosure claimed in the claims, and such modifications should not be understood individually from the technical idea or prospect of the present disclosure.

Claims

1. In the light source device, Primary condenser lens; A secondary condenser lens having the same optical axis as the primary condenser lens and having a smaller diameter than the primary condenser lens; A plurality of laser light sources outputting light parallel to the optical axis; and including a fluorescent plate; The above primary condensing lens is, The light output from the plurality of laser light sources is refracted so that it is incident on an area of ​​the fluorescent plate, and when the light incident on the area of ​​the fluorescent plate is reflected from the fluorescent plate, the reflected light is refracted so that it is incident on the secondary condenser lens parallel to the optical axis. The above secondary condenser lens is, A light source device that refracts light incident on the secondary condenser lens and focuses it to a single point.

2. In paragraph 1, The above light source device is, Further comprising an LED (Light Emitting Diode) light source arranged adjacent to the fluorescent plate and emitting light in the direction of the fluorescent plate; The above primary condensing lens is, The light output from the LED light source and transmitted through the fluorescent plate is refracted so that the light becomes parallel to the optical axis, The above secondary condenser lens is, A light source device that further refracts the light output from the LED light source and refracted through the primary condenser lens and gathers it to the point.

3. In paragraph 1, The above light source device is, A light source device further comprising a mirror disposed adjacent to the fluorescent plate and disposed in an opposite direction of the primary condenser lens with respect to the fluorescent plate.

4. In paragraph 1, The above plurality of laser light sources are, On a plane perpendicular to the optical axis, they are arranged so that the straight-line distances from the optical axis are equal to each other, The light output from the above plurality of laser light sources is: A light source device that passes through a plane that is perpendicular to the optical axis and includes the center point of the secondary condenser lens without incident on the secondary condenser lens, and then is incident on the primary condenser lens.

5. In paragraph 1, The above fluorescent plate, A light source device that, when light of a first wavelength is incident, converts the wavelength of the incident light into a second wavelength longer than the first wavelength and outputs the converted light.

6. In paragraph 1, The light output from the above plurality of laser light sources is It is incident on the first region that is far from the optical axis among the entire region of the first condenser lens, The light reflected from the above fluorescent plate is A light source device that is incident on a second area that is close to the optical axis among the entire area of ​​the first condenser lens.

7. Light source device; A lighting control device for controlling the blinking of the plurality of laser light sources constituting the light source device; and A system comprising a camera for photographing a moving inspection object, the camera facing the light source device with at least a portion of the movement path of the inspection object interposed therebetween; The above light source device is, Primary condenser lens; A secondary condenser lens having the same optical axis as the primary condenser lens and having a smaller diameter than the primary condenser lens; A plurality of laser light sources outputting light parallel to the optical axis; and A system comprising a fluorescent plate.

8. In paragraph 7, The above system, Further comprising a processing device for analyzing an image captured by the camera to obtain drop information including at least one of a speed, a volume, and a trajectory of an ink droplet; The above processing device, A system that communicates with an ink output device that outputs the ink liquid and provides feedback related to the output of the ink liquid based on the drop information.

9. In paragraph 8, The above processing device, Calculate the sharpness of the above image, A system for adjusting the pulse duration of the lighting control device that drives the plurality of laser light sources constituting the light source device based on the sharpness calculated above.

10. In paragraph 9, The above processing device, Store the sharpness value obtained for each pulse duration value, Drive a plurality of laser light sources constituting the light source device based on the stored pulse duration to match the target value of sharpness set according to user input, The above plurality of laser light sources are, On a plane perpendicular to the optical axis, they are arranged so that the straight-line distances from the optical axis are equal to each other, It is divided into multiple groups, and each group is composed of a pair of laser light sources positioned opposite each other based on the optical axis, and the average of the positions of the laser light sources constituting each group matches the position of the optical axis. The above processing device, Based on the pulse duration stored to match the target value of the sharpness, the sharpness of the image captured by the camera is acquired while the plurality of laser light sources are driven and compared with the target value. If the comparison result shows a difference greater than a certain value, the multiple groups are sequentially driven and the sharpness of the images captured while each group is driven is obtained. Identify at least one problematic group based on the sharpness obtained for each group, A system that provides a message indicating that there is a problem with the group identified above.

Images