CN205485034U - Coaxial camera of laser - Google Patents

Abstract

The utility model discloses a coaxial camera of laser, including the direct reflection mirror, the direct reflection mirror includes shell, beam splitter and light filter, the beam splitter and the light filter is all located in the shell, the beam splitter is located on the axis of direct reflection mirror, the beam splitter with the contained angle of axis is 45 degrees, the mirror surface reflective membrane has still been plated on the lateral surface of beam splitter, the inboard of beam splitter is located to the light filter, still include the laser instrument, laser that the laser instrument sent forms collimated beam laser after restrainting through expanding, collimated beam laser along with axis looks vertically direction is through locating on the shell advance the optical window shine to on the mirror surface reflective membrane. Adopt the utility model discloses can effectually arouse the fluorescence of biological material evidence, increase the luminance contrast of biological material evidence such as fingerprint and background object, the fluorescence signal through the better biological material evidence of record of coaxial technique reaches the purpose that shows biological material evidences such as fingerprint.

Description

A kind of laser coaxial photographing unit

Technical field

This utility model relates to the imaging technique of trace material evidence information, more specifically, relates to one Plant laser coaxial photographing unit.

Background technology

Known, due to laser optics focus adjustable, output facula is uniform, is suitable for on-the-spot large area and searches Rope and the trickle observation of characteristic point, have the advantages such as Non-Destructive Testing, and therefore, laser was at material evidence in recent years Status ever more important in inspection technology.Compare traditional alternative light source, the spectral line width of laser The narrowest, for about 1nm, this value is only the 1/15 of alternative light source.This represents laser list Color is fine, and such advantage is that laser can well be filtered, and only leaves material evidence optical information. Evidence at the scene information (especially finger print information), mostly is trace material evidence information, is difficult to or basic nothing Method is found by naked eyes, so needing laser high-power, high brightness to be used as excitation source. Additionally, laser has extraordinary electrical-optical conversion efficiency, say, that can be with less electric energy Obtain brighter, more permanent laser and use duration.Some are difficult to provide the criminal investigation of civil power now by this Field is a kind of advantage, which ensures the use of longer time, the discovery power of higher efficiency.But at present The most external or domestic, search potential material evidence information also the most well to based on luminescence generated by light Recording method, traditional camera the most well filters the ability of exciting light, causes material evidence signal quilt The strongest exciting light is covered, and cannot record the material evidence signal of trace, and traditional camera at all Optical system cannot match with laser instrument, accomplish that good optical axis coordinates and softening illuminates.

Utility model content

For defect present in prior art, the purpose of this utility model be to provide a kind of laser with Axle photographing unit.

For reaching above-mentioned purpose, this utility model adopts the following technical scheme that:

A kind of laser coaxial photographing unit, including directional mirror, described directional mirror include shell, Semi-transparent semi-reflecting beam splitter and for excitation wavelength cut-off optical filter, described beam splitter with And described optical filter is all located in shell；The axis of described directional mirror is located at by described beam splitter On, described beam splitter is 45 degree with the angle of described axis；On the lateral surface of described beam splitter also It is coated with minute surface reflective membrane；Described optical filter is located at the inner side of beam splitter；

Also including laser instrument, the laser that described laser instrument sends forms collimated beam after expanding and swashs Light, described collimated beam laser along with the direction of described axis perpendicular by being located on described shell Light inlet window expose on described minute surface reflective membrane.

Described directional mirror also includes that the inwall of described shell is located at by extinction plate, described extinction plate On, the position of described extinction plate is relative with the position of described light inlet window.

Compared with prior art, a kind of laser coaxial photographing unit of the present utility model is used, it is possible to have The fluorescence exciting biological evidence of effect, increases the biological evidences such as fingerprint anti-with the brightness of background object Difference, preferably records the fluorescence signal of biological evidence by coaxial technology, reaches to manifest the lifes such as fingerprint The purpose of thing material evidence.

Accompanying drawing explanation

Fig. 1 is the principle schematic of a kind of laser coaxial photographing unit of the present utility model.

Detailed description of the invention

The technical solution of the utility model is further illustrated below in conjunction with the accompanying drawings with embodiment.

Refer to a kind of laser coaxial photographing unit shown in Fig. 1, including directional mirror 11, orientation Reflecting mirror includes shell 111, semi-transparent semi-reflecting beam splitter 112 and for cutting excitation wavelength Optical filter 113 only, beam splitter 112 and optical filter 113 are all located in shell 111；Beam splitting Mirror 112 is located on the axis of described directional mirror, and beam splitter is 45 with the angle of described axis Degree；Minute surface reflective membrane also it is coated with on the lateral surface of beam splitter；Optical filter 113 is located at beam splitter 112 Inner side；

Also including laser instrument 12, the laser that laser instrument 12 sends forms collimated beam after expanding and swashs Light, described collimated beam laser along with the direction of axis perpendicular by the light inlet window being located on shell (not shown) exposes on minute surface reflective membrane.

Beam splitter can accept to generate during external light source illumination the vertical illumination light of orienting reflex, again can The optical image allowing made thing body 20 enters camera lens through transparent glasses lens.It addition, laser is through expanding The collimated beam of rear formation, is irradiated on the beam splitter that this block is semi-transparent semi-reflecting, is shone by reflective vertical To by after on made thing body 20, through the light of made thing body reflection or fluorescent light again can vertically to On again pass through beam splitter, filter exciting light to increase the material such as fingerprint and background visitor by optical filter The contrast of body, is transmitted to through anaberration camera lens (not shown) through the flashlight filtered On the bin of CCD21, obtain image clearly.

When laser is irradiated to beam splitter, understands some light and penetrate beam splitter and be irradiated to directional mirror Just on the inwall of light inlet window, reflection light can be taken pictures effect by image.For reaching reflecting mirror internal delustring Effect, installs one block of extinction plate 114, it is possible to achieve preferably disappear on just inwall to light inlet window Light effect.

Laser can be covered whole testee, the most this pattern by laser coaxial light source uniformly Can preferably excite the material evidence samples such as the fingerprint on object surface, saliva, perspiration, carry out photic Light is taken a picture.But coaxial photographing unit can only receive the light coaxial with camera lens, therefore to there being radian Object when detecting, there is certain difficulty.Coaxial light source is used for superfine speck card trace The detection of mark, material evidence self luminescence is more weak, higher to the sensitivity requirement of image device.

Those of ordinary skill in the art is it should be appreciated that above embodiment is intended merely to The purpose of this utility model is described, and is not used as restriction of the present utility model, as long as in this reality With in novel essential scope, change, the modification of embodiment described above all will be fallen in this practicality In the range of novel claim.

Claims (2)

1. a laser coaxial photographing unit, it is characterised in that

Including directional mirror, described directional mirror include shell, semi-transparent semi-reflecting beam splitter with And for the optical filter to excitation wavelength cut-off, described beam splitter and described optical filter are all located at In shell；Described beam splitter is located on the axis of described directional mirror, and described beam splitter is with described The angle of axis is 45 degree；Minute surface reflective membrane also it is coated with on the lateral surface of described beam splitter；Described Optical filter is located at the inner side of beam splitter；

Also including laser instrument, the laser that described laser instrument sends forms collimated beam after expanding and swashs Light, described collimated beam laser along with the direction of described axis perpendicular by being located on described shell Light inlet window expose on described minute surface reflective membrane.

Laser coaxial photographing unit the most according to claim 1, it is characterised in that:

Described directional mirror also includes that the inwall of described shell is located at by extinction plate, described extinction plate On, the position of described extinction plate is relative with the position of described light inlet window.