WO2019041784A1

WO2019041784A1 - Automatic powder supply and trace detection device for extracting fingerprints by means of crime scene powder method and powder supply method thereof

Info

Publication number: WO2019041784A1
Application number: PCT/CN2018/079411
Authority: WO
Inventors: 崔志安; 高绪国; 王舫; 陈大海
Original assignee: 大连圣迈新材料有限公司
Priority date: 2017-08-28
Filing date: 2018-03-19
Publication date: 2019-03-07
Also published as: CN109419513B; CN109419513A

Abstract

An automatic powder supply and trace detection device for extracting fingerprints by means of crime scene powder method and powder supply method thereof; an air pump (3) is in electrical communication with a battery (1), and an air outlet end of the air pump (3) is in communication with a powder bottle (7); an ultra-microporous fluidised bed (10) is installed inside the powder bottle (7), the trace detection powder in the powder bottle (7) being accommodated above the ultra-microporous fluidised bed (10); pressurised air outputted by the air pump (3) passes through the ultra-microporous fluidised bed (10) from below the ultra-microporous fluidised bed (10), forming a plurality of independent air streams acting on the bottom of the trace powder, and producing a mixed gas on the surface of the trace detection powder; one end of an outer shell (22) is provided with a nozzle (20) having a nozzle opening, and a brush head (13) surrounds the nozzle opening, a mixed gas pipe (8) being hermetically connected to the nozzle opening being arranged inside the powder bottle (7), the mixed gas produced in the powder bottle (7) being conveyed to the brush head (13) of the nozzle opening by means of the mixed gas pipe (8), and the trace detection powder in the mixed gas coming into contact with a fingerprint trace and attaching to the surface of the fingerprint trace to form a clear image. The automatic powder supply and trace detection device improves the working environment of police officers, reduces the amount of powder used, and increases the efficiency of sampling work.

Description

Automatic powder feeding inspection device for extracting fingerprint by crime scene powder method and powder supply method thereof

Technical field

The invention belongs to a trace detection tool in the field of public security criminal investigation, in particular to an automatic powder supply inspection device for extracting fingerprints by a crime scene powder method and a powder supply method thereof.

Background technique

Currently, the most common method for fingerprint imaging and analysis of crime scenes is called powder visualization, which is often seen in movies or television. The investigator brushed the fingerprint with fine powder and attached a scotch tape to obtain the shape and trace of the powder (actually the fingerprint). In this way, the investigator can save the fingerprint information to the tape, which is convenient for bringing it back to the laboratory. Conduct an in-depth analysis. If the fingerprint is left on the surface of non-absorbent articles such as metal, plastic, glass, tile, etc., you can use the powder method to extract the fingerprint with a soft brush and a little powder, gently rub the handle to make the powder evenly scattered on the fingerprint, then shake Remove or use the tip of the brush to gently remove excess powder, and the colorless fingerprint will become colored. Commonly used powders are aluminum powder, iron powder, copper powder, graphite powder and the like. Powder extraction of fingerprints is a simple and effective method. However, since the powders used are mostly ultrafine powders, after a large amount of brushing, the powder is suspended in a large amount in the air, which is extremely damaging to the professional technicians; and, by directly brushing the fingerprint surface with a brush, it is easy to apply the fingerprints. damage.

Summary of the invention

In order to solve the above problems caused by the existing powder forming method due to powder suspension air, it is an object of the present invention to provide an automatic powder supply marking apparatus for extracting fingerprints by a crime scene powder method and a powder supplying method therefor.

The object of the present invention is achieved by the following technical solutions:

The automatic powder marking device of the present invention comprises a casing and a battery, an air pump and a powder bottle respectively installed in the casing, wherein the air pump is electrically connected to the battery, and an air outlet end of the air pump is connected to the powder bottle; An ultra-microporous fluidized bed is arranged in the powder bottle, and above the ultra-microporous fluidized bed is a trace powder accommodated in the powder bottle, and the pressurized air output by the air pump is fluidized by the ultra-micropores The bottom of the bed passes through the ultra-microporous fluidized bed, forms a plurality of independent gas streams, acts on the bottom of the trace powder, and generates a mixed gas above the trace powder; the outer end of the outer casing is provided with a nozzle with a spout, the spout There is a brush head around, the inner space enclosed by the brush head is a brush spray tube communicating with the spout; the powder bottle is provided with a mixed gas pipe sealed and connected with the spout, and the mixed gas generated in the powder bottle passes through The mixed gas pipe is sent to the spout and then sprayed through the brush spray nozzle, and the trace powder in the mixed gas contacts the fingerprint mark and adsorbs on the surface of the fingerprint mark to form a clear image;

Wherein: the powder bottle is provided with a gas pipe, the upper end of the gas pipe is connected with the gas outlet end of the air pump, and the lower end is inserted into the ultramicroporous fluidized bed, and the fluidized bed of the ultramicroporous Connected to the lower side, the pressurized air outputted by the air pump is sent to the bottom of the ultra-microporous fluidized bed through the air pipe;

The upper end of the mixed gas pipe is located in the powder bottle and is provided with a disperser. The lower end of the mixed gas pipe is pierced by the powder bottle and is sealingly connected with the spout; the lower end of the mixed gas pipe is connected with the spout on the sprinkler. Have a seal ring;

a plurality of return air holes are uniformly distributed around the nozzles in the circumferential direction, and each of the air return holes is located at a periphery of the mounting position of the brush head on the spray head; a filter screen is disposed between the spray head and the powder bottle. The filter screen is located above each of the return air holes; one end of the outer casing is provided with a powder bottle cap, and the other end is provided with a battery cover, the powder bottle cap is annular, and the axial section of the lower opening is "eight" shape The edge of the upper portion of the "eight" shape is located at the periphery of each of the return air holes;

a switch board and an electric control board are disposed in the outer casing, and the switch board is respectively equipped with a speed control, a power switch and a work switch, wherein the electric control board is electrically connected to the battery, and the work is provided on the connected line. a switch, the air pump is electrically connected to the electric control board, and the speed control and the power switch are arranged on the connection line;

The method for supplying powder for automatic powder feeding inspection equipment for extracting fingerprints by crime scene powder method is:

The battery is powered by an air pump, and an air pump is started. The pressurized gas forms an independent airflow through the ultra-microporous fluidized bed, so that the trace powder in the powder bottle is mixed with air to form a mixed gas. The mixed gas pipe is sent to the nozzle, and then sprayed to the mark inspection surface through the brush spray tube, and the sprayed trace powder directly hits the mark inspection surface, and a part of the trace powder is adsorbed on the mark inspection surface. The surface of the fingerprint trace forms a clear image, and another part of the trace powder is swirled in the brush spray tube under the action of the mixed gas, and merges with the mixed gas sprayed from the nozzle to collide with the mark inspection working surface;

Wherein: the mixed gas ejected, wherein a part of the powder stays on the surface of the mark inspection, and another part of the powder is adsorbed by the brush of the brush head around the brush barrel when passing through the brush spray tube, and the pressurized gas is filtered through the brush head. After the discharge; the trace powder adhered to the brush head is used to replenish the portion which is not developed during the discharge process during the process of scanning the mark inspection surface, and performs secondary development;

The trace powder contained in the pressurized gas filtered by the brush head is recovered by a return air hole opened in the spray head, and filtered through a sieve installed between the spray head and the powder bottle.

The advantages and positive effects of the present invention are:

1. The invention automatically mixes the trace test powder with the air and sends it to the mark inspection surface for sampling sampling. In addition to the function of developing and fixing, the brush head surrounded by the brush head also starts at the same time. To the effect of the loss of powder in the protective mark, under the protection of the brush sprayer enclosed by the brush head, the harmful powder is prevented from being lost in the air, the original brush is sticky and the powder is lost in the work. The way of operation.

2. The powder bottle of the invention is built in the outer casing, simplifies the main structure, facilitates the bottle changing procedure, and solves the phenomenon that the replacement of the powder bottle is improperly caused to cause the loss of the traced powder during the work.

3. The powder adsorbed on the brush head of the present invention can be reused for secondary development, and the portion which is not developed during the mixed gas ejection process is supplemented, so that the result of the mark inspection work is more perfect.

4. The invention provides a trace powder recovery device, and the pressurized air discharged after being filtered by the brush head is again filtered and filtered through a return air hole provided around the brush head to make the air cleaner.

5. The invention fundamentally solves the powder pollution, improves the working environment of the policeman, reduces the amount of powder used, and improves the sampling work efficiency.

DRAWINGS

Figure 1 is a cross-sectional view showing the internal structure of the present invention;

Figure 2 is a right side sectional view of Figure 1;

3 is a schematic view of the appearance of the present invention

Figure 4 is a right side view of Figure 3;

Figure 5 is an exploded view of the present invention after removing the outer casing;

Figure 6 is a schematic structural view of an operating portion of the present invention;

Figure 7 is a working state diagram of the present invention;

Among them: 1 is battery, 2 is electric control board, 3 is air pump, 4 is speed control, power switch, 401 is switch off gear position, 402 is weak gear position, 403 is strong gear position, 5 is switch board , 6 is the working switch, 7 is the powder bottle, 8 is the mixed gas pipe, 9 is the gas pipe, 10 is the ultra-microporous fluidized bed, 11 is the sealing ring, 12 is the filter net, 13 is the brush head, 14 is the return air hole, 15 is a disperser, 16 is a battery cover, 17 is a powder bottle cover, 18 is a scratch inspection working surface, 19 is a brush housing, 20 is a nozzle, 21 is a mounting plate, and 22 is an outer casing.

Detailed ways

The invention will be further described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 to FIG. 6 , the automatic powder supply detecting device for extracting fingerprints by the crime scene powder method comprises a casing 22 and a battery 1 , an electric control board 2 , an air pump 3 , and a working device respectively installed in the casing 22 . The switch 6, the switch board 5, the powder bottle 7 and the speed regulation and power switch 4, wherein the outer casing 22 has a hollow structure, a nozzle 20 is provided at one end, and a powder bottle cover 17 is connected at the end, and the other end of the outer casing 22 is provided with a battery. Cover 16.

The battery 1 is housed in an upper portion of the casing 22, and the air pump 3 is located below the battery 1 and is electrically connected to the battery 1. The switch board 5 is respectively equipped with a speed control, a power switch 4 and a work switch 6. The electric control board 2 is electrically connected to the battery 1, and is provided with a work switch 6 on the connected line, and the air pump 3 is electrically connected to the electric control board 2. And the speed control and power switch 4 are arranged on the connecting line. The air pump 3 is supplied with pressurized air, and the compressed air is supplied to supply the pressurized gas to the powder bottle 7. The air pump 3 of the present invention has a no-load flow rate of 15 cm ³ /s, and the maximum operating pressure of the air outlet is 0.03 mPa. During operation, the no-load airflow intensity is divided into two gears; that is, the switchboard 5 is divided into three gear positions, one is the switch off gear position 401, the second and the third one are the air pump 3 different intensity airflows. The gear positions are the weak gear position 402 and the strong gear position 403; the air flow rate of the weak gear position 402 is 8 cm ³ /s, and the air flow rate of the strong gear position 403 is 12 cm ³ /s. The speed regulation and power switch 4 can be driven to different gear positions according to different loose powder density and working strength at work to adjust the airflow of the mixed gas.

The powder bottle 7 is located below the air pump 3, and the powder bottle 7 is internally provided with a gas pipe 9, a mixed gas pipe 8, a disperser 15 and an ultra-microporous fluidized bed 10, and the ultra-microporous fluidized bed 10 is disposed in the powder bottle 7. In the lower part, the upper end of the gas pipe 9 is fixed in the powder bottle 7 through the mounting plate 21, and the lower end is inserted in the ultra-microporous fluidized bed 10 and communicated with the lower side of the ultra-microporous fluidized bed 10; the ultra-microporous flow Above the chemical bed 10 is a mark powder accommodated in the powder bottle 7. The powder bottle 7 is in communication with the air outlet end of the air pump 3, the communicating portion is located above the mounting plate 21, and the upper end of the air tube 9 is connected to the communication portion, and the pressurized gas output from the air pump 3 can be sent to the ultramicro tube through the air tube 9. Below the pore fluidized bed 10. The mixed gas pipe 8 is located in the middle of the powder bottle 7, and the axial center line is parallel to the axial center line of the gas pipe 9. The upper end of the mixed gas pipe 8 is located in the powder bottle 7 and is provided with a disperser 15. The lower end of the mixed gas pipe 8 is passed through the powder bottle 7 and is sealingly connected to the spout opening formed in the head 20. A sealing ring 11 is provided at the lower end of the mixed gas pipe 8 and the nozzle on the spray head 20 for sealing. A screen 12 is provided at the periphery of the seal ring 11, and the screen 12 is located between the head 20 and the bottom of the powder bottle 7.

The pressurized air of the air pump 3 is carried to the space above the mounting plate 21 in the powder bottle 7, and then sent to the lower portion of the ultra-microporous fluidized bed 10 through the gas pipe 9, and passed through the lower side of the ultra-microporous fluidized bed 10. The ultra-microporous fluidized bed 10 forms an infinite number of independent and small air flows, which acts on the bottom of the trace powder to make the trace powder float in a "boiling" state, and generates a suspended diffuse mixed gas on the surface of the trace powder, and the mixed gas After passing through the disperser 15, it enters the mixed gas pipe 8 and is sent to the spout. The trace powder of the invention has a bulk density of 0.5-1.0 g/cm ³ and a fineness of 500-800 mesh; the ultra-microporous fluidized bed has an ultra-micropore density of ≤1000 mesh, a diameter of 15 mm and a thickness of 2 mm. .

The nozzle on the nozzle 20 is located at an intermediate portion, and a brush head 13 is disposed around the nozzle. The internal space enclosed by the brush head 13 is a brush nozzle 19 communicating with the nozzle. A plurality of return air holes 14 are uniformly distributed in the circumferential direction around the nozzles, and each of the return air holes 14 is located at a periphery of the mounting position of the brush head 13 on the head 20. The screen 12 is located above each of the return air holes 14. The powder bottle cap 17 has a ring shape, and the axial opening of the lower opening has an "eight" shape, and the edge of the upper portion of the "eight" shape is located at the periphery of each of the return air holes 14.

The disperser 15 of the present invention is of the prior art and is made of a metal white steel mesh and has a cylindrical column shape. In the production, depending on the type of powder and the difference between the manufacturer's products, it is optional to use a different sealed metal white steel mesh.

As shown in Fig. 7, when working, the brush head 13 of the automatic powder marking inspection device is erected downward, maintaining the traditional inspection method of the public security police; the angle between the automatic powder marking inspection device and the marking inspection surface 18 A should be greater than 45° to ensure the best working condition.

The glass is used as the mark inspection surface 18, and after the fingerprint is pressed on the glass, the silver powder for criminal investigation is used as the trace powder, and is placed in the powder bottle 7. During operation, the brush head 13 is aligned with the trace collection surface on the mark inspection working surface 18, the work switch 6 is pressed, the air pump 3 is activated, and the speed control and power switch 4 are adjusted from the switch off position to the weak position position 402 (8 cm). ³ / s), the pressurized air is output from the air outlet end of the air pump 3 to the space above the mounting plate 21 in the powder bottle 7, and then sent to the lower side of the ultra-microporous fluidized bed 10 through the air pipe 9, and is supermicroporous The fluidized bed 10 passes under the ultra-microporous fluidized bed 10, forming an infinite number of independent fine gas streams, acting on the bottom of the trace powder, causing the trace powder to float in a "boiling" state, causing a suspension on the surface of the trace powder. The diffused mixed gas, the mixed gas enters the mixed gas pipe 8 through the disperser 15, and is sent to the nozzle to be ejected. The sprayed mark powder directly hits the mark inspection surface 18, and a part of the trace powder is adsorbed on the mark inspection surface 18, so that the remaining traces are clearly revealed, and another part of the trace powder is swirled under the action of the air stream. The inside of the brush spray cylinder 19 merges with the mixed gas sprayed at the spout and re-impacts on the scoring work surface 18, and thus repeated, a clear fingerprint previously pressed can be seen on the surface of the glass. At the same time, when a part of the mixed gas passes through the brush head 13, the trace powder is adsorbed by the bristles of the brush head 13, and the pressurized gas is filtered by the bristles and discharged into the ambient air. In use, according to the working intensity, the speed regulation and power switch can be adjusted to the strong gear position 403 to increase the powder supply amount.

The mark powder that hits the mark inspection surface 18 and adheres to the mark inspection surface 18, because the powder is a micro-flake-like substance, is in an irregular state, and the reflection of the light is scattered, and the observation is not obvious, and the brush is used. The swipe action of the head 13 allows the trace powder to be regularly attached to the mark inspection surface 18, improving the light reflection efficiency, reducing the scattered light, and making the collected traces clearer. The mark powder attached to the brush head 13 can play a secondary development role during the light sweeping process, and supplements the portion which is not developed during the mixed gas discharge process, so that the result of the mark inspection work is more perfect. The brush head 13 also functions to block the filter mark powder, and controls part of the mark powder inside the brush spray tube 19 to avoid spillage and pollute the environment and damage the policeman's body.

After the mixed gas is filtered by the brush head 13, there is still a small amount of trace powder in the pressurized air. The automatic powder supply detecting device of the present invention has a plurality of return air holes 14 formed in the shower head 20 around the brush head 13 to utilize The negative air pressure generated by the air inlet of the air pump 3 draws in the air around the brush head 13 and is filtered through the filter 12 to filter out residual trace powder to make the air cleaner.

Claims

An automatic powder feeding inspection device for extracting fingerprints by a crime scene powder method, comprising: a casing (22) and a battery (1), an air pump (3) and a powder respectively installed in the casing (22) a bottle (7), wherein the air pump (3) is electrically connected to the battery (1), the outlet end of the air pump (3) is in communication with the powder bottle (7); and the powder bottle (7) is installed with super a microporous fluidized bed (10) above which is a trace powder contained in a powder bottle (7), and the pressurized air output by the air pump (3) is The ultra-microporous fluidized bed (10) passes under the ultra-microporous fluidized bed (10), forms a plurality of independent gas streams, acts on the bottom of the trace powder, and generates a mixed gas above the trace powder; the outer shell ( 22) is provided with a nozzle (20) with a spout, and a brush head (13) is arranged around the spout. The inner space enclosed by the brush head (13) is a brush sprayer (19) communicating with the spout. a mixing gas pipe (8) sealingly connected to the spout is provided in the powder bottle (7), and the mixed gas generated in the powder bottle (7) is sent to the spout through the mixed gas pipe (8), and then The brush sprayer (19) is sprayed out, and the mark is detected in the mixed gas. Contacting the end fingerprints and fingerprints are adsorbed on the surface to form a clear image.
The automatic powder marking device for extracting fingerprints by a crime scene powder method according to claim 1, characterized in that: the powder bottle (7) is provided with a gas pipe (9), and the upper end of the gas pipe (9) is The outlet end of the air pump (3) is in communication, and the lower end is inserted on the ultra-microporous fluidized bed (10) and communicates with the underside of the ultra-microporous fluidized bed (10), the air pump (3) The output pressurized air is sent through the air pipe (9) to the underside of the ultra-microporous fluidized bed (10).
The automatic powder marking device for extracting fingerprints by a crime scene powder method according to claim 1, characterized in that the upper end of the mixed gas pipe (8) is located in the powder bottle (7) and is provided with a disperser (15). The lower end of the mixed gas pipe (8) is pierced by the powder bottle (7) and is sealingly connected to the spout.
The automatic powder marking device for extracting fingerprints by a crime scene powder method according to claim 3, characterized in that: the lower end of the mixed gas pipe (8) and the nozzle on the nozzle (20) are provided with a sealing ring (11) ).
The automatic powder marking device for extracting fingerprints by a crime scene powder method according to claim 1, wherein a plurality of return air holes (14) are uniformly distributed around the nozzle on the nozzle (20). Each of the return air holes (14) is located at a periphery of a mounting position of the brush head (13) on the spray head (20); a filter screen (12) is disposed between the spray head (20) and the powder bottle (7), The screen (12) is located above each of the return air holes (14).
The automatic powder marking device for extracting fingerprints by a crime scene powder method according to claim 5, characterized in that: one end of the outer casing (22) is provided with a powder bottle cap (17), and the other end is provided with a battery cover ( 16) The powder bottle cap (17) has a ring shape, and an axial cross section of the lower opening has an "eight" shape, and an edge of the upper portion of the "eight" shape is located at a periphery of each of the return air holes (14).
The automatic powder marking device for extracting fingerprints by a crime scene powder method according to claim 1, characterized in that: the outer casing (22) is provided with a switch board (5) and an electric control board (2), the switch A speed control, a power switch (4) and a work switch (6) are respectively mounted on the board (5), and the electric control board (2) is electrically connected to the battery (1) and is provided on the connected line. The switch (6), the air pump (3) is electrically connected to the electric control board (2), and the speed control and power switch (4) are arranged on the connection line.
A method for supplying powder for an automatic powder supply detecting device for extracting fingerprints by a crime scene powder method according to any one of claims 1 to 7, characterized in that: the battery (1) supplies power to the air pump (3) The air pump (3) is activated, and the pressurized gas forms an independent airflow through the ultra-microporous fluidized bed (10), so that the trace powder in the powder bottle (7) is mixed with air to form a mixed gas. The mixed gas is sent to the nozzle through the mixing gas pipe (8), and then sprayed to the mark inspection surface (18) through the brush spray tube (19), and the sprayed trace powder directly hits the mark inspection surface (18). ), a part of the trace powder is adsorbed on the surface of the fingerprint mark on the mark inspection surface (18) to form a clear image, and another part of the trace powder is swirled in the brush spray tube (19) under the action of the mixed gas, and The mixed gas sprayed from the nozzle collides and strikes the mark inspection surface (18).
A method of supplying powder according to claim 9, wherein said mixed gas is ejected, wherein a part of the powder stays on the surface of the mark, and the other part of the powder is sprayed by the brush while passing through the brush barrel (19). The bristles of the brush head (13) around the cylinder (19) are sucked, and the pressurized gas is filtered and discharged through the brush head (13); the trace powder adhered to the brush head (13) is swept on the scanning surface ( In the process of 18), the portion which is not developed during the ejection process is replenished, and secondary development is performed.
The powder supply method according to claim 9, wherein the trace powder contained in the pressurized gas filtered by the brush head (13) passes through a return air hole opened in the shower head (20) (14) Recycling and filtration through a screen (12) installed between the spray head (20) and the powder bottle (7).