Electromagnetic fingerprint acquisition device
Through the design of electromagnetic induction devices and DC power supplies, the magnetic attenuation and inconvenience of traditional magnetic fingerprint brushes are solved, efficient and convenient fingerprint collection is achieved, adapted to multi-environment use, and reduced replacement costs and two-hand operation needs.
Patent Information
- Application Number
- CN202323278701.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-04
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2033-12-04
AI Technical Summary
The magnetism of traditional magnetic fingerprint brushes attenuate in a long-term magnetic field-free environment, resulting in increased acquisition difficulty and inconvenient operation requiring both hands to cooperate, affecting efficiency.
An electromagnetic fingerprint acquisition device is designed, using electromagnetic induction device and DC power supply, including conductors, wires, control switches and light emitting devices. The suction head structure is designed through coil rods, brush heads and slots, which facilitates one-hand operation and part replacement. .
It improves fingerprint collection efficiency, avoids magnetic attenuation problems, is convenient to operate, adapts to different environments, and is available in dim light, reducing replacement costs and two-hand operation needs.
Smart Images
Figure CN222303919U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of criminal investigation instruments, in particular to an electromagnetic fingerprint collection device. Background Art
[0002] The commonly used traditional magnetic fingerprint brush is made of a fixed structure of a suction head and a grip rod. A permanent magnet is fixed inside the brush with a metal pull rod. The suction head and the grip rod are fixed together. The permanent magnet is moved by pulling the metal rod in the grip rod, so that the magnetic powder adsorbed on the surface of the suction head loses its magnetic force and falls off. There are the following defects when using it: insufficient stability. The magnetism of the permanent magnet is similar to the decay of radioactive elements and has its "half-life". When placed in a non-magnetic field environment for a long time, its magnetism will gradually disappear over time, resulting in insufficient magnetic force and increasing the difficulty of fingerprint collection; secondly, insufficient operability. After using the traditional magnetic brush, there is still a large amount of magnetic powder remaining on the suction head. In order to facilitate carrying and save consumables, the magnetic powder on the suction head needs to be detached. The on-site survey personnel need to cooperate with both hands, holding the grip rod of the magnetic powder brush with one hand and pulling the handle of the metal pull rod with the other hand to retract the magnet in the suction head into the grip rod, so that the magnetic powder adsorbed on the surface of the suction head automatically falls off due to the loss of magnetic force, affecting the operating efficiency. Utility Model Content
[0003] 1. Technical issues to be resolved
[0004] In order to overcome the shortcomings of the existing technology, an electromagnetic fingerprint collection device is proposed, which improves the efficiency of collecting fingerprints, avoids the problem of magnetism disappearance and is easy to operate.
[0005] (II) Technical solution
[0006] The utility model is implemented through the following technical scheme: the utility model proposes an electromagnetic fingerprint collection device, including a shell and a fixed rod fixed in the shell, an electromagnetic induction device is installed on the fixed rod, the electromagnetic induction device includes a conduction seat, a wire and a DC power supply, the conduction seat forms a closed loop with the DC power supply through the wire, a control switch is provided on the closed loop, the electromagnetic induction device also includes a light-emitting device connected to the wire, and a suction head structure is provided at the bottom of the conduction seat.
[0007] Furthermore, the suction head structure includes a coil rod, a brush head and a slot, the coil rod is fixedly connected to the top of the brush head, the slot is opened outside the coil rod, the conductive seat includes a flow guide seat, a slot and an insertion rod, the slot is opened at the bottom of the flow guide seat, and the insertion rod is movably inserted into the inside of the flow guide seat.
[0008] Furthermore, a power supply mounting frame is provided at the tail of the fixing rod, and the DC power supply is fixed on the power supply mounting frame.
[0009] Furthermore, the DC power supply includes two AAA batteries.
[0010] (III) Beneficial effects
[0011] Compared with the prior art, the utility model has the following beneficial effects:
[0012] The electromagnetic fingerprint collection device mentioned in the utility model can improve work efficiency, adapt to different environments, and is easy to operate. It utilizes electromagnetic induction to avoid the problem of magnetism disappearance of permanent magnets, adopts a DC power supply, and is easy to replace. During operation, fingerprint collection can be performed by pressing the control switch with one hand, without the need for two-handed operation. A light-emitting device is provided, so fingerprint collection can be performed even in dimly lit places, and the suction head structure is matched with the conduction seat through the special design of the conduction seat, so it can be easily replaced. In this way, if damage occurs after long-term use, only some parts need to be replaced, saving replacement costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0014] Figure 2 It is a cross-sectional schematic diagram of the conductive seat structure of the utility model.
[0015] Figure 3 It is a circuit diagram of the utility model.
[0016] 1-shell; 2-fixing rod; 3-electromagnetic induction device; 4-control switch; 5-sucking head structure; 31-conduction seat; 32-conducting wire; 33-DC power supply; 311, flow guide seat; 312, slot; 313, plug rod; 51, coil rod; 52, brush head; 53, card slot. DETAILED DESCRIPTION
[0017] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.
[0018] like Figure 1-Figure 3The electromagnetic fingerprint collection device shown in the figure includes a housing 1 and a fixed rod 2 fixedly arranged in the housing 1. An electromagnetic induction device 3 is installed on the fixed rod 2. The electromagnetic induction device 3 includes a conductive seat 31, a wire 32 and a DC power supply 33. The conductive seat 31 forms a closed loop with the DC power supply 33 through the wire 32. A control switch 4 is arranged on the closed loop. The electromagnetic induction device 3 also includes a light-emitting device connected to the wire 32. The light-emitting device is a small light bulb. Fingerprint collection can be performed even in dim light. The conductive seat 3 1 is provided with a suction head structure 5 at the bottom, and the suction head structure 5 includes a coil rod 51, a brush head 52 and a slot 53. The coil rod 51 is fixedly connected to the top of the brush head 52, and the slot 53 is opened outside the coil rod 51. The conductive seat 31 includes a flow guide seat 311, a slot 312 and a plug rod 313. The slot 312 is opened at the bottom of the flow guide seat 311, and the plug rod 313 is movably plugged into the inside of the flow guide seat 311. A power supply mounting frame is provided at the tail of the fixed rod 2, and the DC power supply 33 is fixed on the power supply mounting frame. The DC power supply 33 includes two No. 7 batteries.
[0019] The utility model discloses an electromagnetic fingerprint collection device, which, when used specifically, utilizes the principle of strong adsorption force between the residue of latent fingerprints from sweat and black magnetic powder (magnetic powder prepared with 800 mesh selenium electrostatic copying toner, which is widely used because of its strong adhesion, good display effect, not easy to float, and low toxicity), and cooperates with the device to extract and collect fingerprints. During the specific on-site inspection, the shell 1 is held with one hand, and the thumb presses the control switch 4. At this time, the electromagnetic induction device 3 inside the shell 1 is energized, and a magnetic field is generated around the coil rod of the suction head structure 5 of the shell 1, so that the suction head structure 5 has magnetism. The magnetism of the suction head structure 5 is utilized to dip a proper amount of magnetic powder from a magnetic powder box (the magnetic powder is stored separately in the magnetic powder box), and the magnetic powder is adsorbed on the bottom brush head 52 of the suction head structure 5 to form a magnetic powder spike, and the magnetic powder spike at the bottom of the suction head structure 5 is utilized to gently rub the fingerprint on the on-site surface. When brushing, the brush should be moved along the lines of the fingerprint. After the magnetic powder is combined with the residue on the fingerprint, it is picked up with transparent tape and pasted on the white backing paper to complete the fingerprint collection work. After use, for the magnetic powder remaining at the bottom of the suction head structure 5, the device is moved to the top of the magnetic powder box, and the control switch 4 is turned off to make the magnetic field at the suction head structure 5 disappear, and the magnetic powder falls into the magnetic powder box, that is, the recovery of the magnetic powder is completed. When replacing the brush head 52, it is only necessary to pull the insertion rod 313 to make it disengage from the card slot 53, so that the limit on the coil rod 51 is lost. At this time, the coil rod 51 can be removed and replaced by pulling it out of the slot 312. When installing, it is only necessary to insert the coil rod 51 into the slot 312, so that the coil rod 51 contacts the guide sheet in the slot 312 and can be energized, and then the insertion rod 313 is inserted into the card slot 53 to limit the installation of the coil rod 51, which is convenient for replacing the suction head structure 5.
[0020] The above-described embodiments are merely descriptions of preferred implementations of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary personnel in the field to the technical solution of the present invention should fall within the protection scope of the present invention, and the technical contents of the present invention for protection have been fully recorded in the claims.
Claims
1. An electromagnetic fingerprint collection device, characterized in that: The invention comprises a housing (1) and a fixing rod (2) fixedly arranged in the housing (1); an electromagnetic induction device (3) is mounted on the fixing rod (2); the electromagnetic induction device (3) comprises a conducting seat (31), a wire (32) and a DC power supply (33); the conducting seat (31) forms a closed loop with the DC power supply (33) via the wire (32); a control switch (4) is arranged on the closed loop; the electromagnetic induction device (3) further comprises a light emitting device connected to the wire (32); and a suction head structure (5) is arranged at the bottom of the conducting seat (31).
2. The electromagnetic fingerprint collection device according to claim 1, characterized in that: The suction head structure (5) comprises a coil rod (51), a brush head (52) and a slot (53); the coil rod (51) is fixedly connected to the top of the brush head (52); the slot (53) is arranged outside the coil rod (51); the conductive seat (31) comprises a flow guide seat (311), a slot (312) and an insertion rod (313); the slot (312) is arranged at the bottom of the flow guide seat (311); and the insertion rod (313) is movably inserted into the interior of the flow guide seat (311).
3. The electromagnetic fingerprint collection device according to claim 1, characterized in that: A power supply mounting frame is provided at the rear of the fixing rod (2), and the DC power supply (33) is fixed on the power supply mounting frame.
4. The electromagnetic fingerprint collection device according to claim 1, characterized in that: The DC power source (33) includes two AAA batteries.