High-brightness light source device

Abstract

A light source device is disclosed. The light source device includes a primary focusing lens, a secondary focusing lens that has the same optical axis as the primary focusing lens but a smaller aperture than the primary focusing lens, multiple laser light sources that output light parallel to the optical axis, and a fluorescent screen. The primary focusing lens refracts light output from the multiple laser light sources and focuses the output light onto one area of the fluorescent screen. When light incident on the area of the fluorescent screen is reflected from the fluorescent screen, the primary focusing lens refracts the reflected light and makes it incident on the secondary focusing lens parallel to the optical axis. The secondary focusing lens refracts the light incident on the secondary focusing lens and focuses it onto one point.

Description

Technical Field

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

Background Art

[0002] A microscope is a device for magnifying and viewing very small objects using lenses. Since the brightness tends to become darker as the magnification increases, in order to obtain a bright image, it is necessary to condense the illumination on the object and apply bright light.

[0003] In the past, as a microscope illumination device, a device that uses an arc lamp such as halogen or metal halide and a reflecting mirror for condensing was mainly used, but the arc lamp had problems of low efficiency and heat generation.

[0004] As the efficiency of semiconductor light-emitting elements has improved, the adoption of LED (Light Emitting Diode) elements as microscope light sources has been increasing. Also in the semiconductor or machine vision inspection area, the inspection target has become very small at several micrometers, and a high-magnification microscope optical system is used to inspect this.

[0005] Particularly, in order to capture an image while moving an object, illumination of very high brightness is required during a very short exposure time within several microseconds. Thus, for illumination for capturing a moving object, since the amount of light is not sufficient even when using an LED, a strobe-type light source using an arc lamp is mainly used.

[0006] ]>However, when photographing with an arc lamp in a strobe mode, due to the characteristics of the arc lamp, there is a continuous demand for a more stable and long-life light source because of problems with brightness variation and lifespan.

[0007] Recently, a technique has been introduced that uses a high-power blue laser diode as an alternative to arc lamps. This laser light generated from the light source is irradiated onto a phosphor in a very narrow area, generating broad spectral light through the excitation of the phosphor. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] This disclosure provides a high-brightness light source device that uses multiple focusing lenses to concentrate light emitted from multiple light sources.

[0009] The purposes of this disclosure are not limited to those stated above, and other purposes and advantages of this disclosure not mentioned can be understood from the description below and more clearly from the embodiments of this disclosure. Furthermore, it will be readily apparent that the purposes and advantages of this disclosure can be achieved by the means and combinations thereof described in the claims. [Means for solving the problem]

[0010] A light source device according to one embodiment of the present disclosure includes a primary focusing lens, a secondary focusing lens having the same optical axis as the primary focusing lens and a smaller aperture than the primary focusing lens, a plurality of laser light sources that output light parallel to the optical axis, and a fluorescent screen. The primary focusing lens refracts the light output from the plurality of laser light sources and causes it to enter a region of the fluorescent screen. When the light incident on the region of the fluorescent screen is reflected from the fluorescent screen, the reflected light is refracted and causes it to enter the secondary focusing lens parallel to the optical axis. The secondary focusing lens refracts the light incident on the secondary focusing lens and focuses it to a single point.

[0011] The light source device further includes an LED (Light Emitting Diode) light source positioned adjacent to the fluorescent screen and emitting light in the direction of the fluorescent screen. In this case, the primary focusing lens refracts the light emitted from the LED light source and transmitted through the fluorescent screen so that it is parallel to the optical axis, and the secondary focusing lens can further refract the light emitted from the LED light source and refracted through the primary focusing lens to concentrate it at the aforementioned point.

[0012] The light source device may further include a mirror positioned adjacent to the fluorescent panel and positioned in the opposite direction to the primary focusing lens with respect to the fluorescent panel.

[0013] The plurality of laser light sources may be arranged on a plane perpendicular to the optical axis such that their linear distances from the optical axis are the same. The light emitted from the plurality of laser light sources is perpendicular to the optical axis and can pass through a plane containing the center point of the secondary focusing lens without incident on the secondary focusing lens before being incident on the primary focusing lens.

[0014] When light of a first wavelength is incident on the fluorescent screen, it can convert the wavelength of the incident light to a second wavelength that is longer than the first wavelength and output it.

[0015] On the other hand, the light output from the multiple laser light sources can be incident on a first region of the primary focusing lens that is far from the optical axis, while the light reflected from the fluorescent screen can be incident on a second region of the primary focusing lens that is close to the optical axis.

[0016] A system according to one embodiment of the present disclosure includes a light source device, an illumination control device for controlling the blinking of the plurality of laser light sources constituting the light source device, and a camera facing the light source device across at least a portion of the movement path of the object to be inspected, for photographing the moving object to be inspected. The light source device includes a primary focusing lens, a secondary focusing lens having the same optical axis as the primary focusing lens and a smaller aperture than the primary focusing lens, a plurality of laser light sources that output light parallel to the optical axis, and a fluorescent screen.

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

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

[0019] Furthermore, the processing device can store sharpness values ​​acquired for each pulse duration 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 sharpness value set according to user input. On the other hand, the plurality of laser light sources are arranged on a plane perpendicular to the optical axis such that their linear distances from the optical axis are the same, and are divided into a plurality of groups. Each group consists of a pair of laser light sources positioned opposite each other with respect to the optical axis, and the average of the positions of the laser light sources constituting each group may be matched to the position of the optical axis. At this time, with the plurality of laser light sources driven based on the pulse duration stored so as to match the target sharpness value, the processing device acquires the sharpness of the image captured by the camera and compares it with the target value. If the comparison shows a difference of a certain value or more, the processing device can sequentially drive the plurality of groups and acquire the sharpness of the image captured with each group driven, identify at least one problematic group based on the sharpness acquired for each group, and provide a message notifying that the identified group has a problem. [Effects of the Invention]

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

[0021] The system including the light source device described herein has the advantage of enabling high-speed imaging of the object to be inspected (e.g., ink droplets) based on high-brightness strobe control, and allowing for precise image analysis. [Brief explanation of the drawing]

[0022] [Figure 1] This is a block diagram illustrating the configuration of a light source device according to one embodiment of the present disclosure. [Figure 2] It is a diagram for explaining the arrangement of each component included in a light source device according to an embodiment of the present disclosure. [Figure 3] It is a flowchart for explaining the optical path of the light output from the laser light source of the light source device according to an embodiment of the present disclosure. [Figure 4] It is a diagram for explaining the arrangement of each component of a light source device including an LED light source according to an embodiment of the present disclosure. [Figure 5] It is a diagram for explaining the operation in which an LED light source drives a plurality of laser light sources for each group according to an embodiment of the present disclosure. [Figure 6] It is a diagram for explaining the configuration of a system including a light source device according to an embodiment of the present disclosure and for monitoring ink droplets. [Figure 7a] It is a diagram for explaining the structure of a system according to an embodiment of the present disclosure. [Figure 7b] It is a diagram for explaining the structure of a system according to an embodiment of the present disclosure. [Figure 8] It is a diagram for explaining the result in which the shape of ink droplets is photographed differently according to the period in which the system according to an embodiment of the present disclosure drives a laser light source.

Embodiments for Carrying Out the Invention

[0023] Before specifically explaining the present disclosure, the description methods of this specification and the drawings will be explained.

[0024] First, the terms used in this specification and the claims are general terms selected in consideration of the functions in various embodiments of the present disclosure. However, these terms may change depending on the intentions of those skilled in the art, legal or technical interpretations, and the emergence of new technologies. Also, some terms are those arbitrarily selected by the applicant. Such terms shall be interpreted in the meanings defined in this specification, and if there is no specific term definition, they can also be interpreted based on the overall content of this specification and the ordinary technical common sense in the relevant technical field.

[0025] Furthermore, the same reference numerals or symbols in each of the drawings attached to this specification indicate parts or components that perform substantially the same function. For the sake of explanation and understanding, the same reference numerals or symbols are used to describe different embodiments. That is, even if components with the same reference numeral are shown in multiple drawings, the multiple drawings do not mean that they represent a single embodiment.

[0026] Furthermore, this specification and claims may use terms containing ordinal numbers such as "first" and "second" to distinguish between components. Such ordinal numbers are used to distinguish identical or similar components, and the use of such ordinal numbers should not restrict the meaning of the terms. For example, components combined with such ordinal numbers should not be restricted in terms of their order of use or arrangement by the number. If necessary, the ordinal numbers may be used alternately with each other.

[0027] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “includes” or “consist of” are intended to specify the presence of features, figures, stages, actions, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof.

[0028] In embodiments of this disclosure, terms such as “module,” “unit,” and “part” refer to components that perform at least one function or operation, and such components may be implemented in hardware or software, or in combination of hardware and software. Furthermore, multiple “modules,” “units,” and “parts” may be integrated into at least one module or chip and implemented in at least one processor, unless each needs to be implemented in separate, specific hardware.

[0029] Furthermore, in embodiments of this disclosure, "a part is connected to another part" includes not only direct connection but also indirect connection via other media. Also, "a part includes a component" means, unless otherwise stated to the contrary, that it may include other components rather than excluding them.

[0030] Figure 1 is a block diagram illustrating the configuration of a light source device according to one embodiment of the present disclosure.

[0031] As shown in Figure 1, the light source device 100 includes one or more laser light sources 110, a primary focusing lens 120-1, a secondary focusing lens 120-2, a fluorescent screen 130, and the like.

[0032] The light source device 100 may be included in microscope equipment, semiconductor inspection equipment, cameras, magnifying glasses, etc., and may also be used in a variety of other equipment for providing high-brightness light to minute areas.

[0033] The laser light source 110 may include at least one laser diode, a sighting device / lens (e.g., a collimator lens) for generating parallel light, and at least one drive unit for supplying current to the laser diode.

[0034] A laser diode can generate a laser using a forward semiconductor junction as the active medium, and may, for example, be composed of GaAs, but is not limited to this.

[0035] The light source device 100 may include multiple laser light sources. In this case, each of the multiple laser light sources can output light that travels in directions parallel to each other.

[0036] The primary condensing lens 120-1 and the secondary condensing lens 120-2 are condensing lenses that are sequentially arranged on the same optical axis.

[0037] The primary condensing lens 120-1 and the secondary condensing lens 120-2 may each contain one or more lenses, including planar convex lenses, biconvex lenses, and the like.

[0038] The aperture of the primary condensing lens 120-1 may be larger than the aperture of the secondary condensing lens 120-2.

[0039] The (laser) light output from the aforementioned laser light source 110 can travel in a direction parallel to the optical axes of the focusing lenses 120-1 and 120-2.

[0040] If the light source device 100 includes multiple laser light sources, the linear distance of each of the multiple laser light sources with respect to the optical axis is the same, and the light emitted from the multiple laser light sources can travel in a direction parallel to the optical axis.

[0041] Fluorescent board 130 refers to a board whose surface contains a fluorescent substance.

[0042] The fluorescent screen may include a substrate, a reflector, a fluorescent film, and the like. For example, the substrate may be made of a plastic plate, and the reflector may be made of a conductive mesh, a thin film, and / or a dielectric. The fluorescent film may be coated with Ce:YAG (Yttrium / Aluminum / Garnet coated with Cerium) or a silicate phosphor. However, the configuration of the fluorescent screen is not limited to the above example and can have a variety of configurations using conventional technologies.

[0043] The fluorescent screen 130 can absorb incident high-energy light and convert it into lower-energy light. Specifically, the fluorescent screen 130 can convert incident short-wavelength light into long-wavelength light and reflect or transmit it.

[0044] The fluorescent panel 130 may include a mirror on its back or be installed adjacent to the LED light source. Alternatively, the fluorescent panel 130 may be implemented as part of the LED light source.

[0045] The arrangement of the aforementioned components within the light source device 100 and the paths of light will be explained below with reference to Figures 2 and 3.

[0046] As shown in Figure 2, the primary condensing lens 120-1 and the secondary condensing lens 120-2 may be arranged sequentially on the same optical axis.

[0047] Furthermore, the multiple laser light sources 110-1 and 110-2 may be arranged on a plane perpendicular to the optical axis such that their linear distances from the optical axis are the same. Here, the linear distance from the optical axis may be greater than half the aperture of the secondary focusing lens 120-2.

[0048] As shown in Figure 2, the fluorescent screen 130 may also be positioned on the aforementioned optical axis, and specifically, the secondary condensing lens 120-2, the primary condensing lens 120-1, and the fluorescent screen 130 may be arranged in that order.

[0049] The light emitted from the multiple laser light sources 110-1 and 110-2 may travel in a direction parallel to the optical axis (S310 in Figure 3).

[0050] At this time, the output light may enter the primary condensing lens 120-1 without passing through the secondary condensing lens 120-2.

[0051] Specifically, the light emitted from the multiple laser light sources 110-1 and 110-2 can pass through a plane perpendicular to the optical axis and containing the center point of the secondary focusing lens 120-2 without incident on the secondary focusing lens. The light that has passed through this plane may then be incident on the primary focusing lens 120-1.

[0052] In other words, since the aperture of the primary focusing lens 120-1 is larger than the aperture of the secondary focusing lens 120-2, the light output from multiple laser light sources 110-1 and 110-2 may be directly incident on the primary focusing lens 120-1.

[0053] In this case, the primary focusing lens 120-1 can refract the light output from multiple laser light sources and concentrate the output light onto one area of ​​the fluorescent screen 130 (S320).

[0054] Here, the fluorescent screen 130 can reflect the light incident through the primary condensing lens 120-1 (S330). For this purpose, at least one reflective component may be included on the back surface of the fluorescent screen 130.

[0055] In one embodiment, a mirror may be included in the light source device 100 that is positioned adjacent to the fluorescent board 130 and on the opposite side (back) of the primary focusing lens relative to the fluorescent board.

[0056] Alternatively, at least one LED diode may be placed adjacent to the back of the fluorescent board 130.

[0057] The fluorescent screen 130 can convert the wavelength of incident light to a relatively longer wavelength (short wavelength → long wavelength) and reflect it, and the long-wavelength light reflected from the fluorescent screen 130 can be incident on the primary focusing lens 120-1 again.

[0058] Referring to Figure 2, the light emitted from the multiple laser light sources 110-1 and 110-2 is incident on the region of the primary focusing lens 120-1 that is relatively far from the optical axis (outer region), while the light reflected from the fluorescent screen 130 can be incident on the region of the primary focusing lens 120-1 that is relatively close to the optical axis (inner region).

[0059] The primary condensing lens 120-1 can refract the light (long wavelength) that has been reflected from the fluorescent screen 130 and is incident again (S340). In this case, the light that has been refracted again through the primary condensing lens 120-1 can be incident on the secondary condensing lens 120-2 in a direction parallel to the optical axis.

[0060] The secondary condensing lens 120-2 can then refract the incident light and focus it to a single point (S350).

[0061] In the embodiment described above, the light emitted from multiple laser light sources 110-1 and 110-2 is focused to a single point, so that high-brightness light can be provided to a small area.

[0062] On the other hand, although Figure 2 above shows the case where there are two laser light sources, it goes without saying that one or more additional laser light sources with the same shortest distance from the optical axis may be provided.

[0063] On the other hand, Figure 4 is a diagram illustrating the arrangement of each component of a light source device including an LED light source according to one embodiment of the present disclosure.

[0064] As shown in Figure 4, the light source device 100 may further include an LED light source 140, a heat sink 150, and the like, in addition to the configuration described above.

[0065] The LED light source 140 may be positioned adjacent to the fluorescent board 130, or it may be positioned in the opposite direction from the primary condensing lens 120-1 with respect to the fluorescent board 130.

[0066] The LED light source 140 may include at least one LED (Light Emitting Diode), a driver unit for supplying current to the LED, etc. Alternatively, the LED light source 140 may include at least one micro-LED, an OLED (Organic LED), etc.

[0067] The LED light source 140 may, for example, include at least one LED for outputting blue light. In this case, the output blue light can be converted to white light via a fluorescent plate 130 coated with a phosphor (e.g., yellow). Alternatively, the LED light source 140 may include R / G / B LEDs, respectively, for outputting white light. However, it is not limited to the embodiments described above.

[0068] The LED light source 140 can output light in the direction of the fluorescent screen (the direction of the primary focusing lens 120-1).

[0069] In this case, the light output from the LED light source 140 can pass through the fluorescent screen 130 and enter the primary focusing lens 120-1.

[0070] Here, the light incident on the fluorescent screen 130 can be incident on the primary focusing lens 120-1 with a longer wavelength.

[0071] The primary focusing lens 120-1 can refract the light output from the LED light source 140 and transmitted through the fluorescent screen 130 so that it is parallel to the optical axis. As a result, the refracted light can enter the secondary focusing lens 120-2.

[0072] In this case, the secondary condensing lens 120-2 can further refract the incident light and focus it to the aforementioned point.

[0073] As a result, the light emitted from multiple laser light sources 110-1 and 110-2, along with the light emitted from the LED light source 140, all converge at a single point, providing high-brightness light.

[0074] The heat sink 150 is configured to dissipate heat from the LED light source 140 or the fluorescent plate, and as shown in Figure 4, it may be provided so as to be in contact with the back of the LED light source 140.

[0075] The heat sink 150 can be made of metal, plastic, carbon, ceramic, or other polymer materials with excellent thermal conductivity, but is not limited to these.

[0076] On the other hand, although not shown in the figures, the light source device 100 may include at least one control unit for controlling the driving of the aforementioned multiple laser light sources 110-1, 110-2 and LED light source 140, etc.

[0077] The control unit may include at least one processor or control circuit.

[0078] For example, the control unit can drive multiple laser light sources 110-1, 110-2 and LED light source 140 by user input from operating at least one switch / button provided on the light source device 100. However, user input may be received in a variety of other forms, and user input may also be received via at least one external device capable of wireless communication with the light source device 100.

[0079] The control unit can also control the intensity (luminance) of the light focused at the aforementioned point in stages.

[0080] In this case, the control unit can adjust the number of laser light sources that output light at different brightness levels.

[0081] As a specific example, when a user input is received for the provision of light with a single brightness level, the control unit can be guided to drive the LED light source 140 and one laser light source 110-1 to output light.

[0082] When user input is received for the provision of light with two brightness levels, the control unit can guide the LED light source 140 and the two laser light sources 110-1 and 110-2 to output light.

[0083] Furthermore, the control unit can divide multiple laser light sources into multiple groups and drive them according to their brightness levels.

[0084] In this regard, Figure 5 shows a view from above of multiple laser light sources arranged with respect to the optical axis.

[0085] As shown in Figure 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, and 12 located at the same straight-line distance with respect to the optical axis.

[0086] Multiple laser light sources 110-1, 2, 3, ... can be divided into three groups.

[0087] The first group consists of laser light sources 110-1, 2, 3, and 4; the second group consists of laser light sources 110-5, 6, 7, and 8; and the third group consists of laser light sources 110-9, 10, 11, and 12.

[0088] Referring to Figure 5, each of the aforementioned groups may consist of pairs of laser light sources positioned opposite each other with respect to the optical axis. Furthermore, the average position (centroid) of the laser light sources constituting each group is matched to the position of the optical axis.

[0089] In this case, when user input is received for the provision of light with one level of brightness, the control unit guides the LED light source 140 and the first group (110-1, 2, 3, 4) to drive and output light.

[0090] When user input is received for the provision of two levels of brightness light, the control unit drives the LED light sources 140, the first group (110-1, 2, 3, 4) and the second group (110-5, 6, 7, 8) to output light.

[0091] When user input is received for the provision of light in three brightness levels, the control unit guides 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.

[0092] In this way, when the light output is applied to each group of laser light sources that are facing each other with respect to the optical axis, there is an advantage in that the uniformity of the light provided by the light source device 100 can be maintained with relative consistency.

[0093] On the other hand, the control unit can sequentially drive each of the aforementioned groups according to the time each group has been driven.

[0094] For example, if the first group (110-1, 2, 3, 4) is driven continuously for a threshold time or longer, the control unit can deactivate the first group and drive the second group (110-5, 6, 7, 8) to output light.

[0095] Here, after the second group (110-5, 6, 7, 8) has also been driven continuously for a threshold 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.

[0096] Alternatively, the control unit can divide the total time that the light source device 100 provides into multiple time intervals and drive one group for each divided time interval.

[0097] For example, the first group (110-1, 2, 3, 4) may be driven during the first time interval, the second group (110-5, 6, 7, 8) during the second time interval, and the third group (110-9, 10, 11, 12) during the third time interval, with each group being activated sequentially.

[0098] In this case, since the downtime for each laser light source included in each group is guaranteed, there is a management advantage in that the aging of the laser light sources is delayed. Another advantage is that inspection / repair of the relevant laser light source can be carried out during the downtime period for that laser light source.

[0099] On the other hand, a variety of visual inspection systems can be realized based on the aforementioned light source device 100.

[0100] Figure 6 is a diagram illustrating the configuration of a system including the aforementioned light source device 100 according to one embodiment of the present disclosure.

[0101] System 1000 can encompass a variety of systems for real-time inspection and monitoring of fine particles or the surfaces of fine regions. For example, System 1000 can be used for measuring ink droplets in inkjet printers, semiconductor patterning processes, and semiconductor visual inspection, but is not limited to these applications.

[0102] As shown in Figure 6, the system 1000 may include a light source device 100, an illumination control device 200, a camera 300, etc., according to at least one of the various embodiments described above.

[0103] The lighting control device 200 is a device for controlling the optical output (e.g., blinking) of each of the multiple laser light sources that constitute the light source device 100. For this purpose, the lighting control device 200 may include at least one power supply means, and for example, the lighting control device 200 can control the on / off state of the optical output elements by repeatedly and rapidly switching (on / off) the power supply to the optical output elements that constitute each of the laser light sources. For this purpose, the lighting control device 200 may include at least one switching unit.

[0104] The switching unit can selectively interrupt the power supply (electricity) to the light source device 100 by controlling the switching element. The switching element can be implemented using a variety of elements such as BJT (Bipolar Junction Transistor), FET (Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), thyristor, triac (TRIAC Triode AC switch), and diac (Diode AC switch), but is not limited to these.

[0105] For example, the lighting control device 200 can control the pulse duration in units of 0.1 μs, but is not limited to this.

[0106] To minimize rising delay caused by coil components, the lighting cables connecting the lighting control device 200 and each laser light source of the light source device 100 can be designed to be no longer than 20 cm. As a result, more precise strobe / pulse control becomes possible.

[0107] Camera 300 is configured to photograph the object being inspected (for example, a falling ink droplet). Camera 300 can be implemented using an RGB camera, a TOF (Time of Flight) camera, or similar.

[0108] Camera 300 can be a high-speed or ultra-high-speed camera for photographing a subject (ultrasonic vibrating knife) according to a pre-set period (e.g., 1 / 100 second, 1 / 200 second, 1 / 300 second, etc.), and the shorter the period and the faster the continuous shooting speed, the better it fits the system 1000 according to this disclosure. Camera 300 may include at least one image sensor and a lens that adjusts the path of light to photograph a specific point or range.

[0109] In one embodiment, the camera 300 may be formed in a position opposite the light source device 100, with at least a portion of the movement path of the object to be inspected (for example, the path of ink droplets falling) in between.

[0110] Figure 7a is a diagram illustrating the structure of a system according to one embodiment of the present disclosure. As shown in Figure 7a, the lighting control device 200 may include a strobe controller, a pulse generator, and the like. The strobe controller may include at least one switching element for controlling the blinking of the optical output elements that constitute each laser light source of the light source device 100. The pulse generator is configured to generate / change the pulse duration corresponding to the ON / OFF period of the switching element. Referring to Figure 7a, the camera 300 can capture an image of an ink droplet falling through the shooting range.

[0111] Figure 7b is a diagram illustrating the structure of a system according to one embodiment of the present disclosure. Figure 7b is a diagram showing in more detail the positional relationship between the ink output device that outputs ink droplets and the system 1000.

[0112] As shown in Figure 7b, the ink output device may include a Syringe Pump that provides driving force for outputting ink droplets, a Hemispherical Nozzle for outputting ink droplets, and the like.

[0113] 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 may be 1 ms (1 kHz), but is not limited thereto.

[0114] At this time, the camera 300 of system 1000 can capture multiple images of ink droplets in real time within the lighting environment provided by the light source device 100.

[0115] On the other hand, referring to Figure 6, the system 1000 may further include a processing unit 400 for analyzing images captured by the camera 300 and controlling at least one of the lighting control unit 200 and the camera 300. The processing unit 400 can control the ink output of the ink output device (e.g., output intensity, output size, unit output amount, etc.).

[0116] The processing unit 400 may include at least one memory, processor, etc., and can communicate with the various devices / hardware configurations described above via wired or wireless connection.

[0117] In one embodiment, the processing unit 400 can analyze an image captured by the camera 300 to obtain fall information including at least one of the velocity, volume, and trajectory of an ink droplet. At this time, the processing unit 400 can provide feedback related to the output of the ink droplet based on the fall information, and the output strength of the pump or other components of the ink output device that has received the feedback can be adjusted.

[0118] By utilizing the light source device 100 according to the various embodiments described above, the amount of light provided in the illumination environment becomes very large, thereby improving the image quality of the object to be inspected (e.g., ink droplets) and enabling smoother inspection.

[0119] On the other hand, Figure 8 is a diagram illustrating the result that the shape of the ink droplet is captured differently depending on the period during which the system according to one embodiment of the present disclosure drives the laser light source. Referring to Figure 8, it can be seen that when the pulse duration of the illumination control device 200 is 1 μs, the ink droplet is captured relatively blurred (high blur), while when the pulse duration is 250 ns, the ink droplet is captured clearly.

[0120] Therefore, the lighting control device 200 can drive the laser light source 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.

[0121] In this regard, as one embodiment, the processing device 400 can calculate the sharpness of the image captured by the camera 300. Sharpness is a concept that represents the clarity of the contours of objects in the image.

[0122] Here, the processing unit 400 can adjust the pulse duration of the illumination control device 200 that drives the multiple laser light sources constituting the light source device 100, based on the calculated sharpness. For example, the pulse duration may decrease as the sharpness decreases.

[0123] In one embodiment, the processing unit 400 monitors the sharpness of images captured by the camera 300 at regular intervals. At this time, sharpness can be extracted only from images that contain one or more objects (e.g., ink droplets). Here, whether or not an ink droplet is present can be determined by measuring the contrast value (for example, if the contrast is above a certain value, it is determined that an ink droplet is present), or it can be determined based on at least one object recognition model (e.g., CNN) for identifying ink droplets.

[0124] Here, if sharpness is below a critical value, the lighting control device 200 can reduce the pulse duration by a certain amount, and this process can be repeated until sharpness exceeds a critical value.

[0125] Furthermore, in one embodiment, the processing device 400 can monitor the amount of change in sharpness during the stepwise change process of pulse duration.

[0126] At this time, the processing unit 400 can store the sharpness value acquired for each pulse duration in at least one memory. In connection with this, the processing unit 400 can set a target sharpness value by user input and drive multiple laser light sources based on the stored pulse duration so as to match the target sharpness value.

[0127] On the other hand, when multiple laser light sources are driven based on pulse durations stored to match a target sharpness value, the processing unit 400 can actually acquire the sharpness of the image captured by the camera 300 and compare it with the target value. If the acquired sharpness differs from the target value by a certain amount or more, the processing unit 400 can identify that a problem has occurred in at least one of the multiple laser light sources.

[0128] In this case, the processing unit 400 can sequentially drive each of the groups (first group, second group, and third group) shown in Figure 5 and obtain the sharpness of the images captured with each group selectively driven. For example, the first sharpness of an image captured with only the first group driven, the second sharpness of an image captured with only the second group driven, and the third sharpness of an image captured with only the third group driven can be calculated.

[0129] Here, the processing unit 400 can compare the first to third sharpness values ​​and identify at least one of the first to third sharpness values ​​whose values ​​differ by a certain amount or more. For example, if the value of the second sharpness is less than the first and third sharpness values ​​by a certain amount or more, the processing unit 400 can identify that a problem has occurred in at least one of the second group of laser light sources corresponding to the second sharpness.

[0130] In this case, the processing unit 400 can provide a message indicating that a problem has occurred in the second group.

[0131] For this purpose, the processing unit 400 may include a display, a speaker, etc., and can output the message visually / auditoryly. Alternatively, the processing unit 400 may communicate with at least one external device, including a display and / or a speaker, via wired / wireless communication to transmit the message. As a result, the user can identify and inspect at least one of the second group of laser light sources if there is a problem.

[0132] On the other hand, the various embodiments described above can be realized by combining multiple embodiments, as long as they do not conflict with each other.

[0133] On the other hand, while preferred embodiments of the Disclosure have been illustrated and described above, the Disclosure is not limited to the specific embodiments described above, and various modifications can be made by persons with ordinary skill in the art to which the Disclosure pertains, without departing from the gist of the Disclosure claimed in the claims. Furthermore, such modifications should not be understood individually from the technical ideas or prospects of the Disclosure.

Claims

1. Light source device; A lighting control device for controlling the blinking of multiple laser light sources constituting the light source device; and A system including a camera positioned opposite the light source device, with at least a portion of the path of the object being inspected in between, for photographing the moving object; The aforementioned light source device is Primary focusing lens; A secondary focusing lens having the same optical axis as the primary focusing lens and a smaller aperture than the primary focusing lens; Multiple laser light sources that output light parallel to the optical axis; and Includes fluorescent boards; The aforementioned system, A processing device that analyzes images captured by the aforementioned camera to obtain fall information including at least one of the velocity, volume, and trajectory of an ink droplet; further comprising The aforementioned processing apparatus is It communicates with an ink output device that outputs ink liquid, and provides feedback related to the output of the ink liquid based on the drop information. The sharpness of the above image is calculated, A system that adjusts the pulse duration of the lighting control device that drives the plurality of laser light sources constituting the light source device, based on the calculated sharpness.

2. The aforementioned processing apparatus is The sharpness value obtained for each pulse duration value is saved. Multiple laser light sources constituting the light source device are driven based on the stored pulse duration, which is matched to the target value of sharpness set by user input. The plurality of laser light sources are On a plane perpendicular to the optical axis, the following arrangements are made such that the straight-line distances from the optical axis are the same for all of them. The system is divided into multiple groups, each group consisting of pairs of laser light sources positioned opposite each other with respect to the optical axis, and the average of the positions of the laser light sources constituting each group is matched to the position of the optical axis. The aforementioned processing apparatus is With the plurality of laser light sources driven based on pulse durations stored to match the target value of sharpness, the sharpness of the image captured by the camera is acquired and compared with the target value. If the comparison results show a difference of a certain value or more, the multiple groups are driven sequentially, and the sharpness of the image captured while each group is driven is obtained. Based on the sharpness obtained for each group, identify at least one problematic group. The system according to claim 1, which provides a message indicating that there is a problem with the identified group.

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