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 high brightness light source devices, and more particularly to light source devices that focus the output of at least one laser light source and / or LED light source to concentrate intense light in a very small area. [Background technology]

[0002] A microscope is a device that uses lenses to magnify and view very small objects. The higher the magnification, the darker the image tends to be. Therefore, in order to obtain a bright image, it is necessary to focus the illumination onto the object and apply bright light.

[0003] In the past, illumination devices for microscopes mainly used arc lamps such as halogen or metal halide lamps and condensing mirrors, but arc lamps had problems with low efficiency and heat generation.

[0004] As the efficiency of semiconductor light emitting devices improves, LED (Light Emitting Diode) elements are increasingly being used as microscope light sources. In the semiconductor or machine vision inspection field, inspection targets are becoming extremely small, measuring just a few micrometers, and high-magnification microscope optics are being used to inspect them.

[0005] In particular, capturing an image of a moving object requires extremely bright illumination for an extremely short exposure time of within a few microseconds. Because LEDs do not provide enough light for capturing images of such moving objects, strobe-type light sources using arc lamps are mainly used.

[0006] However, when using an arc lamp for strobe photography, there are problems with brightness fluctuation and lifespan due to the characteristics of the arc lamp, and there is a continuing demand for a more stable and long-life light source.

[0007] Recently, a technology has been introduced to replace arc lamps by using a high-power blue laser diode to irradiate a very narrow area of phosphor with laser light generated from the light source, thereby generating wide spectrum light through excitation of the phosphor. Summary of the Invention [Problem to be solved by the invention]

[0008] The present disclosure provides a high-brightness light source device that utilizes multiple condenser lenses to condense light output from multiple light sources.

[0009] The objects of the present disclosure are not limited to the objects mentioned above, and other unmentioned objects and advantages of the present disclosure can be understood from the following description and can be more clearly understood by the embodiments of the present disclosure. Furthermore, it will be easily understood that the objects and advantages of the present disclosure can be achieved by the means recited in the claims and combinations thereof. [Means for solving the problem]

[0010] According to an embodiment of the present disclosure, a light source device includes a primary condensing lens, a secondary condensing lens having the same optical axis as the primary condensing lens but a smaller aperture than the primary condensing lens, a plurality of laser light sources outputting light parallel to the optical axis, and a fluorescent screen. The primary condensing lens refracts the light output from the plurality of laser light sources to make it incident on a region of the fluorescent screen, and when the light incident on the region of the fluorescent screen is reflected from the fluorescent screen, the reflected light is refracted to make it incident on the secondary condensing lens parallel to the optical axis, and the secondary condensing lens refracts the light incident on the secondary condensing lens to collect it at a single point.

[0011] The light source device further includes an LED (Light Emitting Diode) light source disposed adjacent to the fluorescent screen and outputting light toward the fluorescent screen. In this case, the primary condensing lens refracts the light output from the LED light source and transmitted through the fluorescent screen so that the light is parallel to the optical axis, and the secondary condensing lens further refracts the light output from the LED light source and refracted by the primary condensing lens to concentrate the light at the point.

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

[0013] The plurality of laser light sources may be arranged on a plane perpendicular to the optical axis so that the linear distances from the optical axis are the same, and the light output from the plurality of laser light sources may pass through a plane perpendicular to the optical axis and including a center point of the secondary focusing lens without being incident on the secondary focusing lens, and then be incident on the primary focusing lens.

[0014] When light of a first wavelength is incident on the fluorescent screen, the fluorescent screen may convert the wavelength of the incident light into a second wavelength longer than the first wavelength and output the converted light.

[0015] Meanwhile, the light output from the plurality of laser light sources may be incident on a first region of the entire area of the primary condenser lens that is far from the optical axis, and the light reflected from the fluorescent plate may be incident on a second region of the entire area of the primary condenser lens that is close to the optical axis.

[0016] According to an embodiment of the present disclosure, a system includes a light source device, an illumination control device for controlling on / off of the plurality of laser light sources constituting the light source device, and a camera for capturing images of a moving inspection object, the camera facing the light source device across at least a portion of the movement path of the inspection object. The light source device includes a primary condenser lens, a secondary condenser lens having the same optical axis as the primary condenser lens but a smaller aperture than the primary condenser 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 the image captured by the camera to obtain drop information including at least one of a velocity, a volume, and a trajectory of the ink droplets, wherein the processing device communicates with an ink output device that outputs the ink droplets and provides feedback related to the output of the ink droplets based on the drop information.

[0018] In this case, the processing device can calculate the sharpness of the image and adjust the pulse duration of the lighting control device that drives the multiple laser light sources that constitute the light source device based on the calculated sharpness.

[0019] The processing device may 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 durations to match a target sharpness value set in response to a user input. The plurality of laser light sources may be arranged on a plane perpendicular to the optical axis so that the linear distances from the optical axis are the same, and divided into a plurality of groups, each group consisting of a pair of laser light sources positioned opposite each other with respect to the optical axis, and an average position of the laser light sources constituting each group may be matched to a position of the optical axis. The processing device may acquire sharpness of an image captured by the camera while the plurality of laser light sources are driven based on the stored pulse durations to match the target sharpness value, compare the sharpness with the target value, and, if a difference of a certain value or more is found as a result of the comparison, sequentially drive the plurality of groups to acquire sharpness of images captured while each group is driven, identify at least one group having a problem based on the sharpness acquired for each group, and provide a message notifying the identified group that a problem exists. [Effects of the Invention]

[0020] The light source device according to the present disclosure has an advantage in that it can provide high-intensity light in a concentrated manner in a narrow or extremely small area by concentrating 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 that it is possible to capture an object to be inspected (e.g., ink droplets) at high speed based on high-intensity strobe control, and perform precise image analysis. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a block diagram illustrating a configuration of a light source device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram for explaining the arrangement of components included in a light source device according to an embodiment of the present disclosure. [Figure 3] 5 is a flowchart illustrating a path of light output from a laser light source of a light source device according to an embodiment of the present disclosure. [Figure 4] 1 is a diagram illustrating the arrangement of components of a light source device including an LED light source according to an embodiment of the present disclosure. [Figure 5] 10A and 10B are diagrams illustrating an operation in which an LED light source drives a plurality of laser light sources in groups according to an embodiment of the present disclosure. [Figure 6] 1 is a diagram illustrating the configuration of a system for monitoring ink drops, including a light source device according to an embodiment of the present disclosure. [Figure 7a] FIG. 1 is a diagram illustrating a structure of a system according to an embodiment of the present disclosure. [Figure 7b] FIG. 1 is a diagram illustrating a structure of a system according to an embodiment of the present disclosure. [Figure 8] 10A and 10B are diagrams illustrating the results of capturing images of ink droplets with different shapes depending on the cycle at which the system drives the laser light source according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] Before specifically describing the present disclosure, the method of describing the present specification and drawings will be described.

[0024] First, the terms used in this specification and 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 engineers in the relevant technical field, legal or technical interpretations, and the emergence of new technologies. In addition, some terms are arbitrarily selected by the applicant. Such terms shall be interpreted as defined in this specification, and if there is no specific definition of a term, they may be interpreted based on the general content of this specification and common general technical knowledge in the relevant technical field.

[0025] Furthermore, the same reference numbers or symbols in the drawings attached to this specification indicate parts or components that perform substantially the same functions. For ease of explanation and understanding, the same reference numbers or symbols are used in different embodiments. In other words, even if components having the same reference numbers are shown in multiple drawings, the multiple drawings do not mean that they represent one embodiment.

[0026] Furthermore, in this specification and claims, terms including ordinal numbers such as "first" and "second" may be used to distinguish between elements. Such ordinal numbers are used to distinguish between identical or similar elements, and the use of such ordinal numbers should not be interpreted as limiting the meaning of the terms. For example, the order of use or arrangement of elements associated with such ordinal numbers should not be limited by the numbers. If necessary, each ordinal number may be used interchangeably.

[0027] In this specification, the singular includes the plural unless the context clearly indicates otherwise. In this application, the terms "comprise" or "comprise" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] In the embodiments of the present disclosure, the terms "module," "unit," "part," etc. are used to refer to a component that performs at least one function or operation, and such a component may be realized by hardware or software, or a combination of hardware and software. Furthermore, multiple "modules," "units," "parts," etc. may be integrated into at least one module or chip and realized by at least one processor, unless each needs to be realized by a specific individual piece of hardware.

[0029] Furthermore, in the embodiments of the present disclosure, a part being connected to another part includes not only a direct connection but also an indirect connection via another medium. Furthermore, unless otherwise specified, a part including a certain component does not mean that it can exclude other components, but that it can further include other components.

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

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

[0032] The light source device 100 may be included in a microscope, a semiconductor inspection device, a camera, a magnifying glass, or other various devices for providing high-brightness light to a minute area.

[0033] The laser light source 110 may include at least one laser diode, a collimator / lens (e.g., a collimator lens) for generating parallel light, and may include at least one driver 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 be constructed of, by way of example and not limitation, GaAs.

[0035] The light source device 100 may include a plurality of laser light sources, each of which may output light beams traveling in parallel directions.

[0036] The primary condenser lens 120-1 and the secondary condenser lens 120-2 correspond to condenser lenses arranged in sequence on the same optical axis.

[0037] Each of the primary condenser lens 120-1 and the secondary condenser lens 120-2 may include one or more lenses, and may include a planar convex lens, a double-convex lens, or the like.

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

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

[0040] When the light source device 100 includes multiple laser light sources, the linear distances of the multiple laser light sources relative to the optical axis are the same, and the light output from the multiple laser light sources can travel in a direction parallel to the optical axis.

[0041] The fluorescent plate 130 refers to a plate whose surface contains fluorescent material.

[0042] The fluorescent screen may include a substrate, a reflector, a fluorescent film, etc. 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 examples, and may be configured using various conventional technologies.

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

[0044] The fluorescent screen 130 may include a mirror on the backside, or may be installed adjacent to the LED light source, or may be realized such that the fluorescent screen 130 is included in the LED light source.

[0045] The arrangement of the above-mentioned components and the path of light within the light source device 100 will be described below with reference to FIGS.

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

[0047] The laser light sources 110-1 and 110-2 may be arranged on a plane perpendicular to the optical axis so that the linear distance from the optical axis is the same as each other. 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 FIG. 2, the fluorescent screen 130 may also be arranged on the optical axis, specifically, the secondary condenser lens 120-2, the primary condenser lens 120-1, and the fluorescent screen 130 may be arranged in this order.

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

[0050] At this time, the output light may be incident on the primary condenser lens 120-1 without passing through the secondary condenser lens 120-2.

[0051] Specifically, the light output from the plurality of laser light sources 110-1 and 110-2 may pass through a plane perpendicular to the optical axis and including the center point of the secondary focusing lens 120-2 without being incident on the secondary focusing lens, and the light that has passed through the plane may be incident on the primary focusing lens 120-1.

[0052] That is, since the aperture of the primary condenser lens 120-1 is larger than the aperture of the secondary condenser lens 120-2, the light output from the plurality of laser light sources 110-1 and 110-2 may be directly incident on the primary condenser lens 120-1.

[0053] In this case, the primary condenser lens 120-1 refracts the light beams output from the plurality of laser light sources and condenses the light beams onto one area of the fluorescent screen 130 (S320).

[0054] Here, the fluorescent screen 130 can reflect the light incident through the primary condenser lens 120-1 (S330). For this purpose, the rear surface of the fluorescent screen 130 may include at least one structure for reflection.

[0055] In one embodiment, the light source device 100 may include a mirror disposed adjacent to the fluorescent screen 130 and disposed on the opposite side (rear side) of the primary condenser lens with respect to the fluorescent screen.

[0056] Alternatively, at least one LED diode may be disposed adjacent to the rear surface of the fluorescent screen 130 .

[0057] The fluorescent screen 130 can convert the wavelength of the incident light into 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 again on the primary focusing lens 120-1.

[0058] Referring to FIG. 2, the light output from the plurality of laser light sources 110-1 and 110-2 is incident on an area (outside) of the entire area of the primary focusing lens 120-1 that is relatively far from the optical axis, whereas the light reflected from the fluorescent screen 130 can be incident on an area (inside) of the entire area of the primary focusing lens 120-1 that is relatively close to the optical axis.

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

[0060] The secondary condenser lens 120-2 refracts the incident light and condenses it at one point (S350).

[0061] According to the above-described embodiment, the light beams output from the plurality of laser light sources 110-1 and 110-2 are focused at one point, so that high-intensity light can be provided in a small area.

[0062] Meanwhile, although FIG. 2 shows the case where there are two laser light sources, it goes without saying that one or more additional laser light sources having the same shortest distance from the optical axis may be provided.

[0063] Meanwhile, FIG. 4 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.

[0064] As shown in FIG. 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 above-described components.

[0065] The LED light source 140 may be disposed adjacent to the fluorescent screen 130, or may be located on the opposite side of the fluorescent screen 130 from the primary condenser lens 120-1.

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

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

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

[0070] Here, the light incident on the fluorescent screen 130 can be incident on the primary condenser lens 120-1 with its wavelength increased.

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

[0072] In this case, the secondary focusing lens 120-2 can further refract the incident light and focus it at the same point.

[0073] As a result, the light output from the plurality of laser light sources 110-1 and 110-2 and the light output from the LED light source 140 are all concentrated at one point, thereby 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 may be provided in contact with the rear surface of the LED light source 140, as shown in FIG.

[0075] The heat sink 150 can be made of, but is not limited to, metal, plastic, carbon, ceramic, or other polymeric material that has good thermal conductivity.

[0076] Meanwhile, although not shown, the light source device 100 may include at least one control unit for controlling the driving of the plurality of laser light sources 110-1 and 110-2, the LED light source 140, and the like.

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

[0078] For example, the control unit may drive the laser light sources 110-1 and 110-2 and the LED light source 140 in response to a user input operating at least one switch / button provided on the light source device 100. However, the user input may be received in various other forms, such as through at least one external device capable of wired or wireless communication with the light source device 100.

[0079] The control unit can also control the intensity (brightness) of the light focused at the above-mentioned point in stages.

[0080] In this case, the control unit may adjust the number of laser light sources that output light for each brightness level to be different.

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

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

[0083] The control unit may also divide the laser light sources into a plurality of groups and drive the groups according to brightness levels.

[0084] In this regard, FIG. 5 is a diagram showing a top view of a plurality of laser light sources arranged with respect to the optical axis.

[0085] As shown in 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, and 12 positioned at the same linear distance from the optical axis.

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

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

[0088] 5, each group may be composed of a pair of laser light sources positioned opposite each other based on the optical axis, and the average (center of gravity) of the positions of the laser light sources constituting each group may match the position of the optical axis.

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

[0090] When a user input for providing two-level brightness light is received, 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 a user input for providing light of three levels of brightness is received, the control unit drives the LED light sources 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 light output is added in units of groups each composed of laser light sources facing each other based on the optical axis, there is an advantage that the uniformity of the light provided by the light source device 100 can be maintained relatively consistently.

[0093] Meanwhile, the control unit can sequentially drive each group according to the time for which each group has been driven.

[0094] For example, if the first group (110-1, 2, 3, 4) is continuously driven for a threshold time or more, the control unit may 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 been continuously driven for a threshold time or more, 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 may divide the entire time during which the light source device 100 provides light into a plurality of time periods and drive one group for each divided time period.

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

[0098] In this case, the downtime of the laser light sources in each group is guaranteed, which has the advantage of delaying the deterioration of the laser light sources, and also has the advantage of allowing inspection / repair of the laser light sources during the downtime of each laser light source.

[0099] Meanwhile, various visual inspection systems can be realized based on the above-described light source device 100.

[0100] FIG. 6 is a diagram illustrating the configuration of a system including the light source device 100 described above according to an embodiment of the present disclosure.

[0101] The system 1000 may be applicable to various systems for real-time inspection / monitoring of fine particles or surfaces of fine areas, etc. For example, the system 1000 may be used in, but is not limited to, inkjet ink droplet measurement, semiconductor patterning processes, and semiconductor appearance inspection.

[0102] As shown in 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.

[0103] 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. For example, the lighting control device 200 may control the on / off of the light output elements constituting each laser light source by repeatedly and quickly switching (on / off) the power supply to the light output elements. To this end, the lighting control device 200 may include at least one switching unit.

[0104] The switching unit controls the switching element to selectively cut off the power supply (electric power) supplied to the light source device 100. The switching element can be realized by various elements such as, but not limited to, a BJT (Bipolar Junction Transistor), a FET (Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), a thyristor, a TRIAC (Triode AC switch), and a DIAC (Diode AC switch).

[0105] As an 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 the rising delay due to the coil component, the length of the lighting cable 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, thereby enabling more precise strobe / pulse control.

[0107] The camera 300 is configured to capture an image of an object to be inspected (for example, a falling ink droplet). The camera 300 can be realized by an RGB camera, a TOF (Time of Flight) camera, or the like.

[0108] The camera 300 may be a high-speed camera or an ultra-high-speed camera for capturing images of an object (ultrasonic vibration knife) at a preset interval (e.g., 1 / 100 seconds, 1 / 200 seconds, 1 / 300 seconds, etc.), and the shorter the interval and the faster the continuous capture speed, the more suitable it is for the system 1000 according to the present disclosure. The camera 300 may include at least one image sensor and a lens for adjusting the path of light to capture a specific point or range.

[0109] In one embodiment, the camera 300 may be formed at a position facing the light source device 100 across at least a part of the movement path of the inspection object (for example, the falling path of ink droplets).

[0110] FIG. 7a is a diagram illustrating the structure of a system according to an embodiment of the present disclosure. As shown in FIG. 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 on / off 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, the camera 300 can capture an image by photographing ink droplets falling through a photographing range.

[0111] 7b is a diagram for explaining the structure of a system according to an embodiment of the present disclosure, and shows in more detail the positional relationship between the ink output device that outputs ink droplets and the system 1000.

[0112] As shown in 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, 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 to this. For example, the ink output device may have an ink ejection cycle of 1 ms (1 kHz), but is not limited to this.

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

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

[0116] The processing device 400 may include at least one memory, processor, etc., and may be connected to and communicate with the various devices / hardware configurations described above via wired / wireless means.

[0117] In one embodiment, the processing device 400 may acquire drop information including at least one of the velocity, volume, and trajectory of the ink droplets by analyzing the image captured by the camera 300. In this case, the processing device 400 may provide feedback related to the output of the ink droplets based on the drop information, and may adjust the output strength of a pump or the like of an ink output device that receives the feedback.

[0118] By utilizing the light source device 100 according to the various embodiments described above, the amount of light provided for the lighting environment is significantly increased, thereby improving the image quality of the object to be inspected (e.g., ink droplets) and enabling smooth inspection.

[0119] 8 is a diagram illustrating the results of capturing different shapes of ink droplets depending on the cycle at which the laser light source is driven by the system according to an embodiment of the present disclosure. Referring to FIG. 8, it can be seen that when the pulse duration of the lighting control device 200 is 1 μs, the ink droplets are captured relatively blurred (large blur), whereas when the pulse duration is 250 ns, the ink droplets are 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, and may preferably be 250 ns or less, but is not limited to this.

[0121] In this regard, in one embodiment, the processing unit 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 an image.

[0122] Here, based on the calculated sharpness, the processing device 400 can adjust the pulse duration of the lighting control device 200 that drives the multiple laser light sources that make up the light source device 100. For example, the lower the sharpness, the shorter the pulse duration may be.

[0123] In one embodiment, the processing device 400 periodically monitors the sharpness of images captured by the camera 300. At this time, sharpness can be extracted only for images that contain one or more objects (e.g., ink droplets). Whether an ink droplet is included can be determined by measuring the contrast value (e.g., if the contrast is above a certain value, it is determined that an ink droplet is included) or can be determined based on at least one object recognition model (e.g., CNN) for identifying ink droplets.

[0124] Here, if the sharpness is less than the critical value, the lighting control device 200 may decrease the pulse duration by a certain amount, and this process may be repeated until the sharpness becomes equal to or greater than the critical value.

[0125] In addition, as an embodiment, the processing device 400 may monitor the amount of change in sharpness as the pulse duration changes stepwise.

[0126] At this time, the processing device 400 may store the sharpness value acquired for each pulse duration value in at least one memory. In this regard, the processing device 400 may set a target sharpness value according to a user input and may drive a plurality of laser light sources based on the stored pulse duration to match the target sharpness value.

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

[0128] In this case, the processing device 400 may sequentially drive each group (first group, second group, third group) in Figure 5 and obtain the sharpness of an image captured when each group is selectively driven. For example, a first sharpness of an image captured when only the first group is driven, a second sharpness of an image captured when only the second group is driven, and a third sharpness of an image captured when only the third group is driven may be calculated.

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

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

[0131] For this purpose, the processing device 400 may include a display, a speaker, etc., and may output the 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 message. As a result, the user may identify that there is a problem with at least one of the laser light sources of the second group and perform an inspection.

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

[0133] On the other hand, although 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 technical field to which the disclosure pertains without departing from the gist of the present disclosure as claimed in the claims, and such modifications should not be understood individually from the technical ideas and perspectives of the present disclosure.

Claims

1. In the light source device, Primary focusing 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 that output light parallel to the optical axis; and a fluorescent screen; The primary focusing lens is refracting the light output from the plurality of laser light sources to cause it to be incident on one region of the fluorescent screen, and when the light incident on the region of the fluorescent screen is reflected from the fluorescent screen, refracting the reflected light to cause it to be incident on the secondary condenser lens parallel to the optical axis; The secondary focusing lens is A light source device that refracts the light incident on the secondary focusing lens and focuses it at one point.

2. The light source device is The fluorescent screen further includes an LED (Light Emitting Diode) light source disposed adjacent to the fluorescent screen and emitting light in the direction of the fluorescent screen; The primary focusing lens is refracting the light output from the LED light source and transmitted through the fluorescent screen so that the light is parallel to the optical axis; The secondary focusing lens is The light source device according to claim 1 , wherein the light output from the LED light source and refracted by a primary condensing lens is further refracted and concentrated at the point.

3. The light source device is 2. The light source device according to claim 1, further comprising: a mirror disposed adjacent to the fluorescent screen and disposed in an opposite direction to the primary condenser lens with respect to the fluorescent screen.

4. The plurality of laser light sources include: On a plane perpendicular to the optical axis, the lenses are arranged so that their linear distances from the optical axis are the same; The light output from the plurality of laser light sources is 2. The light source device according to claim 1, wherein the light passes through a plane perpendicular to the optical axis and including a center point of the secondary condenser lens without being incident on the secondary condenser lens, and then is incident on the primary condenser lens.

5. The fluorescent screen is 2. The light source device according to claim 1, wherein when light of a first wavelength is incident, the light source device converts the wavelength of the incident light into a second wavelength longer than the first wavelength and outputs the converted light.

6. The light output from the plurality of laser light sources is The light is incident on a first area of the primary condenser lens that is far from the optical axis, The light reflected from the fluorescent screen is The light source device according to claim 1 , wherein the light is incident on a second area of the primary condenser lens that is closer to the optical axis than the entire area of the primary condenser lens.

7. Light source device; an illumination control device for controlling the on / off of the plurality of laser light sources constituting the light source device; and a camera that faces the light source device across at least a portion of the path of movement of the inspection object and captures an image of the moving inspection object, The light source device is Primary focusing 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 that output light parallel to the optical axis; and a fluorescent screen;

8. The system comprises: a processing unit that analyzes the image captured by the camera to obtain drop information including at least one of the velocity, volume, and trajectory of the ink droplets; The processing device includes: The system of claim 7 , in communication with an ink output device that outputs ink drops, and providing feedback related to the output of the ink drops based on the drop information.

9. The processing device includes: Calculating the sharpness of the image; The system according to claim 8 , further comprising: adjusting a pulse duration of the lighting control device that drives the plurality of laser light sources that constitute the light source device, based on the calculated sharpness.

10. The processing device includes: Save the sharpness values obtained for each pulse duration value, driving a plurality of laser light sources constituting the light source device based on a pulse duration stored so as to match a target value of sharpness set by a user input; The plurality of laser light sources include: On a plane perpendicular to the optical axis, the lenses are arranged so that their linear distances from the optical axis are the same; The laser beam is divided into a plurality of groups, each group being composed of a pair of laser light sources positioned opposite each other based on the optical axis, and an average position of the laser light sources constituting each group being matched to the position of the optical axis; The processing device includes: obtaining sharpness of an image captured by the camera while the laser light sources are driven based on the pulse durations stored to match the target sharpness value, and comparing the sharpness with the target sharpness value; If the comparison result indicates a difference of a predetermined value or more, the plurality of groups are sequentially driven, and sharpness of images captured while each group is driven is acquired, respectively; Identifying at least one problematic group based on the sharpness obtained for each group; The system of claim 9 , further comprising providing a message to the identified group informing them of a problem.

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