Portable ultra-trace evidence search and discovery device

Abstract

The application discloses a portable ultramicro evidence searching and finding device, which comprises a main body, a display screen arranged on the top surface of the main body and a lens connected to the bottom surface of the main body, an excitation light source and a light guide cover are arranged at the front part of the lens, the excitation light source comprises an LED light source, a green laser light source and a blue laser light source, the green laser and the blue laser emitted by the green laser light source and the blue laser light source are irradiated on the center position of the mouth of the light guide cover and are located on the middle line position of the lens; the lens comprises a CCD lens assembly and a microscope lens arranged at the rear part of the CCD lens assembly, a narrow wave filter is arranged at the front part of the microscope lens; the portable ultramicro evidence searching and finding device integrates the LED light source and the laser light source, when the LED light source is used, the evidence trace is searched in a large area, after the evidence trace is found, the evidence trace is excited by the laser, so that the evidence trace is displayed and is easy to be observed and extracted.

Description

Technical Field

[0001] This invention belongs to the field of biological trace detection, and more specifically relates to a portable device for searching and discovering trace evidence. Background Technology

[0002] Evidence search and discovery devices are crucial equipment for searching and discovering physical evidence at crime scenes. Among existing technologies, laser evidence examination instruments are commonly used. These instruments use lasers as excitation sources, leveraging the high brightness and monochromaticity of lasers to induce light emission in trace evidence. They are particularly suitable for searching various types of physical evidence at police scenes and for non-destructive testing of fingerprints. Non-destructive testing can be used to examine various biological traces, such as semen stains, vaginal secretions, saliva, blood, urine stains, and bone and tooth fragments at crime scenes; to non-destructively display fingerprints on partial objects, such as walls and packaging boxes at crime scenes; to non-destructively examine and display sweat fingerprints treated with ninhydrin, ninhydrin, or 502 glue, or to display fingerprints with fluorescent powder; to examine bruises and bite marks after human injury; to examine residues from gunshots or explosives; and to search for suspicious fibers at crime scenes.

[0003] Generally, on-site physical evidence is characterized by diversity, complexity, and minute quantity. Before laser activation, a large-scale search using conventional lighting is required. Only after the physical evidence is found can laser activation be performed. This concealment means that various tools and equipment are needed for the discovery and extraction of physical evidence, making the operation cumbersome and affecting the efficiency of discovery and extraction. Summary of the Invention

[0004] The purpose of this invention is to provide a portable ultra-micro evidence search and discovery device that integrates LED light source and laser light source. When using LED light source, it searches for evidence traces in a large area. After finding the evidence traces, it is then excited by laser to make the evidence traces visible, making them easy to observe and extract.

[0005] The present invention provides a portable ultra-micro evidence search and discovery device, comprising a main body, a display screen disposed on the top surface of the main body, and a lens connected to the bottom surface of the main body. An excitation light source and a light guide cover are disposed in front of the lens. The excitation light source includes an LED light source, a green laser light source, and a blue laser light source. The green laser and blue laser emitted by the green laser light source and the blue laser light source both irradiate the center position of the opening of the light guide cover and are located at the center line of the lens.

[0006] The lens includes a CCD lens assembly and a microscope head disposed at the rear of the CCD lens assembly. A narrow-wavelength filter group is disposed at the front of the microscope head. The narrow-wavelength filter group includes a first narrow-wavelength filter, a second narrow-wavelength filter, and a third narrow-wavelength filter, which are respectively corresponding to the LED light source, the green laser light source, and the blue laser light source.

[0007] Preferably, a photosensor is provided at the rear of the microscope head, and a control circuit board is connected to the photosensor via a signal connection. The control circuit board is connected to the display screen via a signal connection.

[0008] Preferably, the narrow-wavelength filter group includes a narrow-wavelength filter lever connected to the front of the microscope head via a rotating shaft. The first narrow-wavelength filter, the second narrow-wavelength filter, and the third narrow-wavelength filter are arranged along the circumferential direction of the narrow-wavelength filter lever to ensure that there is always a narrow-wavelength filter located at the front of the microscope head. A dial ring is connected to the narrow-wavelength filter lever, and the dial ring is coaxially arranged with the microscope head and its outer diameter is adapted to the outer diameter of the microscope head.

[0009] Preferably, the CCD lens assembly includes a lens housing coaxially mounted to the front of the microscope head and a CCD lens placed inside the lens housing and coaxially mounted to the microscope head. The LED light source, green laser light source, and blue laser light source are all mounted on the lens housing, and the light guide is fixedly connected to the lens housing.

[0010] Preferably, a vertical mounting groove is provided around the CCD lens on the front surface of the lens housing, the LED light source is installed in the vertical mounting groove, and two inclined mounting grooves are provided outside the vertical mounting groove. The two inclined mounting grooves are symmetrical about the axis of the lens housing. The green laser light source and the blue laser light source are respectively installed in the two inclined mounting grooves, and the axis of the inclined mounting groove passes through the center of the opening of the light guide cover.

[0011] Preferably, both the green laser source and the blue laser source include a laser emitter and a lens group disposed in front of the laser emitter. The lens group includes a collimating lens group, a heat dissipation lens group, a high-pass narrow-wave filter, a refractive lens group, and a uniform light lens group arranged in sequence. The collimating lens group is disposed close to the laser emitter. The LED source includes an LED emitter and a uniform light lens group and a narrow-wave lens group disposed in front of the LED emitter in sequence.

[0012] Preferably, a plurality of heat sinks are evenly distributed on the lens housing.

[0013] The beneficial effects of the portable ultra-micro evidence search and discovery device of the present invention are: it integrates LED light source and laser light source, and when using LED light source, it searches for evidence traces in a large area. After finding the evidence traces, it is then excited by laser to make the evidence traces visible, which are easy to observe and extract. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the portable ultra-micro evidence search and discovery device according to the technical solution of the present invention.

[0015] Figure 2 This is a schematic diagram of the portable ultra-micro evidence search and discovery device of the present invention from an upward view.

[0016] Figure 3 for Figure 1 Sectional view along line AA.

[0017] Figure 4 for Figure 1 Sectional view along the BB direction.

[0018] Figure 5 This is a schematic diagram of the lens housing structure.

[0019] Figure 6 This is a cross-sectional view of the lens housing.

[0020] Figure 7 This is a schematic diagram of a narrow-wavelength filter array. Detailed Implementation

[0021] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with specific embodiments and the accompanying drawings.

[0022] like Figure 1 and Figure 2 As shown, the portable ultra-micro evidence search and discovery device of the present invention includes a main body 1, a display screen 2 disposed on the top surface of the main body 1, and a lens 3 connected to the bottom surface of the main body 1. An excitation light source and a light guide cover 7 are disposed at the front of the lens 3. The excitation light source includes an LED light source 81, a green laser light source 82, and a blue laser light source 83. The green laser light emitted by the green laser light source 82 and the blue laser light source 83 both irradiate the center position of the opening of the light guide cover 7 and are located at the centerline of the lens 3, as shown. Figure 3 The focal point of the dotted line.

[0023] The lens 3 includes a CCD lens assembly 6 and a microscope head 4 disposed at the rear of the CCD lens assembly 6. A narrow-wavelength filter group 5 is disposed at the front of the microscope head 4. The narrow-wavelength filter group 5 includes a first narrow-wavelength filter 511, a second narrow-wavelength filter 512, and a third narrow-wavelength filter 513, which correspond to the LED light source 81, the green laser light source 82, and the blue laser light source 83, respectively.

[0024] Based on the above technical solution, during normal large-area evidence searches, the microscope lens magnification is adjusted to the minimum, the LED light source is turned on, and the green laser light source 82 and blue laser light source 83 are turned off. Then, the main body 1 is held and moved within the space. At this time, the light guide hood 7 is far from the ground, table, or other surface where the evidence is being searched. Under the strong light of the LED light source, the evidence traces can be detected and located. After the evidence traces are detected, the light guide hood 7 is placed over them. At this time, the LED light source is turned off, and either the green laser light source 82 or the blue laser light source 83 is turned on. An observation notch 71 is provided on the light guide hood 7, allowing the operator to observe whether the laser emitted by the green laser light source 82 or the blue laser light source 83 is illuminating the evidence traces. Then, the focus of the microscope lens is adjusted according to the appearance, area, or size of the evidence traces, so that the photosensitive sensor installed at the rear of the microscope lens can detect clear evidence traces. Finally, the traces are displayed on the screen, allowing the operator to directly observe them. At the same time, operators can also extract evidence from the observation gap 71 position.

[0025] Based on the above technical solution, the LED light source emits white light. The green laser light source 82 and the blue laser light source 83 both emit green and blue laser light, respectively, which illuminate the center of the opening of the light guide cover 7 and are located at the centerline of the lens 3. Figure 3 The focal point of the dotted line, that is, the laser shining directly in front of the lens, ensures that the physical evidence in front of the lens has good excitation ability, thus ensuring the display effect of the physical evidence.

[0026] Based on the above technical solution, this portable ultra-micro evidence search and discovery device can be used to find evidence traces in a large area and to excite the found evidence traces. It integrates LED light source and laser light source. When using LED light source, evidence traces are searched in a large area. After the evidence traces are found, they are excited by laser to make the evidence traces visible and easy to observe and extract.

[0027] In this technical solution, a photosensor is provided at the rear of the microscope lens 4. A control circuit board is connected to the photosensor, and the control circuit board is connected to the display screen 2. The photosensor obtains analog signals of the physical evidence traces observed on the microscope lens, which are then controlled and processed by the control circuit board and finally displayed directly on the display screen for easy observation.

[0028] In this technical solution, such as Figure 7 As shown, the narrow-wavelength filter group 5 includes a narrow-wavelength filter lever 53 connected to the front of the microscope head 4 via a rotating shaft 56. The first narrow-wavelength filter 511, the second narrow-wavelength filter 512, and the third narrow-wavelength filter 513 are arranged along the circumference of the narrow-wavelength filter lever 53, ensuring that at least one narrow-wavelength filter is always located at the front of the microscope head 4. A dial ring 52 is connected to the narrow-wavelength filter lever 53, and the dial ring 52 is coaxially arranged with the microscope head 4 and its outer diameter is adapted to the outer diameter of the microscope head 52. The first narrow-wavelength filter 511 transmits white light at a wavelength of 450 nm, the second narrow-wavelength filter 512 transmits green laser light at a wavelength of 520 nm, and the third narrow-wavelength filter 513 transmits blue laser light at a wavelength of 445 nm. The first narrow-wavelength filter 511, the second narrow-wavelength filter 512 and the third narrow-wavelength filter 513 are used in conjunction with the LED light source 81, the green laser light source 82 and the blue laser light source 83, respectively.

[0029] In this technical solution, such as Figure 3 and Figure 4 As shown, the CCD lens assembly 6 includes a lens housing 61 coaxially mounted to the front of the microscope head 4 and a CCD lens 62 placed inside the lens housing 61 and coaxially mounted to the microscope head 4. The LED light source 81, green laser light source 82, and blue laser light source 83 are all mounted on the lens housing 61. The light guide 7 is fixedly connected to the lens housing 61. A vertical mounting groove 63 is provided around the CCD lens 62 on the front surface of the lens housing 61, and the LED light source 81 is mounted within the vertical mounting groove 63. Two inclined mounting grooves 64 are provided outside the vertical mounting grooves 63, and the two inclined mounting grooves 64 are symmetrically arranged about the axis of the lens housing 61. The green laser light source 82 and blue laser light source 83 are respectively mounted within the two inclined mounting grooves 64, and the axis of the inclined mounting grooves 64 passes through the center of the opening of the light guide 7.

[0030] Based on the above technical solution, the excitation light source is installed inside the lens housing 61, so that the LED light source 81 forms a large aperture on the front exterior of the light guide 7, facilitating large-area search for evidence. After the evidence is found, it is excited by a laser, making the evidence more visible and easier to observe and extract. The inclined mounting slot 64 is designed so that the laser shines precisely on the center of the opening of the light guide 7, and is located at the front of the lens.

[0031] In this technical solution, both the green laser source 82 and the blue laser source 83 include a laser emitter and a lens group disposed in front of the laser emitter. The lens group includes a collimating lens group, a heat dissipation lens group, a high-pass narrow-wave filter, a refractive lens group, and a uniform light-diffusing lens group arranged sequentially. The collimating lens group is positioned close to the laser emitter to obtain the required wavelength of laser light and to ensure that the laser light illuminates the center of the opening of the light guide hood 7, placing the evidence directly in front of the lens for easy observation. The LED source includes an LED emitter and a uniform light-diffusing lens group and a narrow-wave lens group disposed sequentially in front of the LED emitter, obtaining a uniform LED illumination aperture and avoiding large-area searches of the evidence.

[0032] In this technical solution, several heat sinks are evenly distributed on the lens housing to facilitate heat dissipation of the excitation light source.

[0033] The technical solution of the present invention has been described above by way of example in conjunction with the embodiments and accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A portable device for searching and discovering trace amounts of physical evidence, characterized in that, It includes a main body, a display screen mounted on the top surface of the main body, and a lens connected to the bottom surface of the main body. An excitation light source and a light guide cover are provided in front of the lens. The excitation light source includes an LED light source, a green laser light source, and a blue laser light source. A vertical mounting groove is formed around the CCD lens on the front surface of the lens housing. The LED light source is installed in the vertical mounting groove. Two inclined mounting grooves are provided outside the vertical mounting groove. The two inclined mounting grooves are symmetrical about the axis of the lens housing. The green laser light source and the blue laser light source are respectively installed in the two inclined mounting grooves. The axis of the inclined mounting groove passes through the center of the opening of the light guide cover, so that the green laser and the blue laser emitted by the green laser light source and the blue laser light source both irradiate the center of the opening of the light guide cover and are located at the centerline of the lens. The lens includes a CCD lens assembly and a microscope head disposed at the rear of the CCD lens assembly. The CCD lens assembly includes a lens housing coaxially mounted at the front of the microscope head and a CCD lens disposed inside the lens housing and coaxially mounted with the microscope head. The LED light source, green laser light source and blue laser light source are all mounted on the lens housing, and the light guide is fixedly connected to the lens housing. A narrow-wavelength filter group is provided at the front of the microscope head. The narrow-wavelength filter group includes a first narrow-wavelength filter, a second narrow-wavelength filter, and a third narrow-wavelength filter, which correspond to the LED light source, the green laser light source, and the blue laser light source, respectively. The first narrow-wavelength filter, the second narrow-wavelength filter, and the third narrow-wavelength filter are arranged along the circumferential direction of the narrow-wavelength filter lever to ensure that there is always a narrow-wavelength filter at the front of the microscope head. A lever ring is connected to the narrow-wavelength filter lever. The lever ring is coaxially arranged with the microscope head and its outer diameter is adapted to the outer diameter of the microscope head.

2. The portable ultra-micro evidence search and discovery device according to claim 1, characterized in that, A photosensor is provided at the rear of the microscope head, and a control circuit board is connected to the photosensor. The control circuit board is connected to the display screen.

3. The portable ultra-micro evidence search and discovery device according to claim 1, characterized in that, Both the green laser source and the blue laser source include a laser emitter and a lens group disposed in front of the laser emitter. The lens group includes a collimating lens group, a heat dissipation lens group, a high-pass narrow-wave filter, a refractive lens group, and a beam-uniforming lens group arranged in sequence. The collimating lens group is disposed close to the laser emitter. The LED source includes an LED emitter and an LED beam-uniforming lens group and a narrow-wave lens group disposed in front of the LED emitter in sequence.

4. The portable ultra-micro evidence search and discovery device according to claim 1, characterized in that, The lens housing is provided with several heat dissipation grooves evenly distributed on it.

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