CN212569393U - Reflection imaging portable fingerprint photographic device - Google Patents

Abstract

The utility model provides a reflection imaging portable fingerprint photographic device, which has convenient operation and small volume, not only can realize the photography in a bright field and a dark field, but also can weaken or even eliminate the interference of object background patterns and obtain fingerprint images with higher quality; it includes the box and sets up in photograph hole on the box, be equipped with light source assembly, spectroscope in the box, light source assembly includes the light source, the light that the light source sent passes through the spectroscope forms the illumination light path, is located illumination light path is terminal offer the material hole of examining that is used for shining the fingerprint object on the box, be located examine material hole department the light of fingerprint object reflection after being shone form the formation of image light path by the spectroscope reflection, the formation of image light path sets up the optical element who has reflection of light function, photograph hole set up in the warp light path after the optical element reflection is terminal on the box.

Description

Reflection imaging portable fingerprint photographic device

Technical Field

The utility model relates to a court science technology field specifically is portable fingerprint camera device of reflection formation of image.

Background

Photographing is an important link in fingerprint and other trace evidence inspection work, if visible fingerprints and fingerprints processed by a physical or chemical method are found on site or on inspection materials, photographing and recording are carried out as soon as possible so as to prevent the fingerprints from fading or being accidentally damaged; the light distribution photography is that the brightness distribution of the reflected light of the material to be detected is adjusted and controlled by selecting a white light source or a light source with other wavelengths and changing the incidence angle and the direction of the illuminating light, to enhance the contrast between fingerprint lines and the background pattern of the object, reduce or eliminate the interference of the background pattern of the object, among them, the light distribution photography has various methods, and for fingerprints attached to the surface of a smooth impermeable and semipermeable planar object, the most common bright field photography is directed reflection photography, the most common dark field photography is dark field photography, in different sites, the types and conditions of fingerprints and objects thereof are different, different light distribution methods are required to be selected to effectively display fingerprint lines and detail characteristics, however, different light distribution devices are often used singly, for example, a directional reflector device commonly used in fingerprint photography can only be used for directional reflection photography in bright field; the dark field light distribution device can only take a dark field photograph, and in addition, the size of the existing light distribution device and the attached shading parts is large, so that the existing light distribution device is difficult to operate by a single person, and the existing light distribution device is difficult to use due to complicated and changeable environmental conditions such as space, light and the like during field exploration, so that a good effect is difficult to achieve. For a bright field image of a fingerprint obtained by using the directional reflection light distribution device, when the distance between a camera lens and a fingerprint object is long, namely the optical path of an imaging light path is long, the contrast between a fingerprint line and the object background is large, the interference of a background pattern is small, the fingerprint display quality is good, but the device height is high, and the miniaturization is difficult; for dark field photography of fingerprints, a point light source located beside a camera lens is usually adopted for lighting, sometimes reflected bright spots of a light source at the edge of a fingerprint interfere the appearance of fingerprint lines, or the fingerprint presents the condition that one side of the fingerprint line is brighter and the other side of the fingerprint line is darker, and a dark field photography device which has no bright spot interference, uniform line illumination and better contrast is lacked.

Therefore, the light distribution device is integrated into a miniaturized portable device to realize various bright field and dark field photographing of fingerprints, reduce background pattern interference and obtain fingerprint images with high quality, and the light distribution device has very important significance for fixed photographing and extraction of field fingerprints.

Disclosure of Invention

To the above problem, the utility model provides a portable fingerprint camera device of reflection formation of image, its convenient operation, it is small, not only can realize bright field and dark field and take a picture, and can weaken or even eliminate the interference of object background pattern, obtain the higher fingerprint image of quality.

The technical scheme is as follows: portable fingerprint camera device of reflection formation of image, include the box and set up in photograph hole on the box, be equipped with light source assembly, spectroscope in the box, light source assembly includes light source, its characterized in that: the light that the light source sent passes through the spectroscope forms the illumination light path, is located illumination light path end offer on the box be used for shining the fingerprint object examine the material hole, be located examine material hole department the light that the fingerprint object was shone the back reflection and is passed through the spectroscope reflection forms the formation of image light path, set up the optical element who has the reflection of light function on the formation of image light path, the photograph hole set up in the warp the light path after the optical element reflection is terminal on the box.

Furthermore, a condenser lens and an imaging objective lens are arranged in the box body, the condenser lens is arranged on the illumination light path between the light source and the spectroscope, and the imaging objective lens is arranged on the imaging light path between the spectroscope and the photographing hole;

furthermore, the optical distance between the condenser and the light source is the same as the focal length of the condenser, the optical element adopts a first reflective mirror, the imaging objective lens is arranged between the spectroscope and the first reflective mirror, and the spectroscope and the first reflective mirror are arranged at an included angle of 45 degrees with the optical axis of the imaging objective lens;

furthermore, the photographic hole is arranged on the box body right above the first reflective mirror, the material detection hole is arranged at the bottom of the box body, the spectroscope is arranged right above the material detection hole, and the condenser and the light source are sequentially arranged on the illumination light path above the spectroscope;

the light source assembly further comprises a shell and an adjustable diaphragm, the light source and the adjustable diaphragm are both assembled in the shell, the adjustable diaphragm is arranged at the light emitting end of the light source and coaxially arranged with the light source, a diaphragm worm wheel is rotatably connected to the outer wall of the shell, and the diaphragm worm wheel is connected with a handle on the adjustable diaphragm;

furthermore, a driving mechanism is arranged in the box body, and the light source assembly is driven by the driving mechanism to enable the light source to move on the focal plane of the condenser lens;

furthermore, the driving mechanism comprises an assembly fixing frame arranged in the box body, the light source assembly is arranged on the assembly fixing frame, a screw rod penetrates through the assembly fixing frame and is in rotary connection with the assembly fixing frame, two ends of the screw rod are in rotary connection with the inner wall of the box body, a first sliding rod and a second sliding rod both penetrate through the assembly fixing frame and are connected with the inner wall of the box body, the screw rod is connected with a first worm wheel, a first servo motor and a first worm connected with the first servo motor are arranged on the inner wall of the box body, a second servo motor and a second worm connected with the second servo motor are arranged on the assembly fixing frame, the first worm is in rotary connection with the first worm wheel, and the second worm is in rotary connection with the second worm;

further, a second reflecting mirror is arranged in the box body and arranged on the illumination light path between the light source and the collecting mirror;

furthermore, the second reflective mirror is adjustable in angle through a rotating mechanism;

furthermore, the rotating mechanism comprises a reflector fixing frame, the second reflector is fixed on the reflector fixing frame, the reflector fixing frame is connected with the worm gear II through a reflector rotating shaft, two ends of the reflector rotating shaft are rotatably connected to the inner wall of the box body, a servo motor III and a worm III in three-phase connection with the servo motor are mounted on the inner wall of the box body, and the worm III is rotatably connected with the worm gear II.

The beneficial effects of the utility model are that, obtain approximate parallel light through the cooperation of light source assembly with the condensing lens, compare greatly reduced device overall height with traditional directional reflection grading method, the miniaturization has been realized, on this basis, and can obtain bright field and dark field fingerprint image, the light that the fingerprint object reflects under the light source shines reachs the photographic hole after the twice reflection of spectroscope and the optical element that has the function of reflecting light, the optical path of formation of image light path has been prolonged, thereby the contrast of fingerprint line and object background in the greatly enhanced bright field directional reflection mode, weaken or even eliminate the interference of object background pattern, can obtain the bright field directional reflection fingerprint image that the quality is higher, better use value has; in addition, the beam splitter is creatively utilized to reflect and image, so that only one optical element with a light reflecting function is needed to be arranged in an imaging light path, and on the premise of not increasing the total height of the device, enough space can be ensured to be reserved between the optical element and the photographic hole for arranging optical devices with a zooming function, so that the defect that optical zooming times of some cameras are low is overcome, and fingerprint imaging is clearer.

Drawings

Fig. 1 is a schematic perspective view of a first embodiment of the present invention;

fig. 2 is a schematic front view of a first embodiment of the present invention;

FIG. 3 is a sectional view taken along line A-A of FIG. 2;

fig. 4 is a schematic perspective view of a second embodiment of the present invention;

fig. 5 is a schematic front view structure diagram of a second embodiment of the present invention;

FIG. 6 is a cross-sectional view taken along line B-B of FIG. 5;

FIG. 7 is a side sectional view of a light source assembly according to one or more embodiments of the present invention;

fig. 8 is a front view of a light source assembly according to the first and second embodiments of the present invention;

FIG. 9 is a light emission schematic view in bright field directional reflection mode and dark field mode of FIG. 8;

fig. 10 is a view showing illumination in the dark field directional reflection mode of fig. 8.

In fig. 1 to 10: 1. a box body; 2. a light source assembly; 3. a beam splitter; 4. a condenser lens; 5. an imaging objective lens; 6. a first reflective mirror; 7. material checking holes; 8. a photo hole; 9. a second reflective mirror; 10. a housing; 11. a light source; 12. an adjustable diaphragm; 13. a handle; 14. a blade; 15. a diaphragm worm gear; 16. an assembly mount; 17. a screw; 18. a first worm wheel; 19. a first servo motor; 20. a first worm; 21. a servo motor II; 22. a second worm; 23. a mirror holder; 24. a second worm gear; 25. a servo motor III; 26. a worm III; 27. a mirror rotating shaft; 28. a central light source; 29. a peripheral light source; 30. a first sliding rod; 31. and a second sliding rod.

Detailed Description

Example one

As shown in fig. 1 to 3, 7 and 8, the portable fingerprint camera device with reflective imaging includes a box body 1 and a camera hole 8 formed in the box body 1, a light source assembly 2 and a spectroscope 3 are arranged in the box body 1, the light source assembly 2 includes a light source 11, light emitted by the light source 11 transmits through the spectroscope 3 to form an illumination light path, a material detection hole 7 for illuminating a fingerprint object (not shown in the figure) is formed in the box body 1 at the tail end of the illumination light path, reflected light of the irradiated fingerprint object at the material detection hole 7 is reflected by the spectroscope 3 to form an imaging light path, an optical element with reflective function is arranged on the imaging light path, the camera hole 8 is arranged on the box body 1 at the tail end of the light path reflected by the optical element, and the camera hole 8 is externally connected with a camera (not shown.

A condenser lens 4 and an imaging objective lens 5 are further arranged in the box body 1, the condenser lens 4 is arranged on an illumination light path between the light source 11 and the spectroscope 3, the imaging objective lens 5 is arranged on an imaging light path between the spectroscope 3 and the photographic hole 8, the optical element adopts a first reflective mirror 6, and specifically, the imaging objective lens 5 is arranged between the spectroscope 3 and the first reflective mirror 6; the material detecting hole 7 is arranged at the bottom of the box body 1, the spectroscope 3 is arranged right above the material detecting hole 7, the condenser lens 4 and the light source 11 are sequentially arranged above the spectroscope 3, and the photographing hole 8 is arranged on the box body 1 right above the first reflecting mirror 6; the optical distance between the condenser lens 4 and the light source 11 is the same as the focal length of the condenser lens 4, and the spectroscope 3 and the first reflective mirror 6 are arranged at an included angle of 45 degrees with the optical axis of the imaging objective lens 5, so that the collimation of the imaging light path is ensured.

The light source assembly 2 is arranged at the top in the box body 1, the light source assembly 2 further comprises a shell 10 and an adjustable diaphragm 12, the adjustable diaphragm 12 is in the prior art, details are not repeated in the patent, the light source 11 can adopt a single light source or a combined light source, and can be arranged according to specific conditions, in the first embodiment of the patent, a combined light source is adopted as the light source, the prior art is adopted, namely, the combined light source is formed by combining a central light source 28 and a peripheral light source 29, the central light source 28 adopts a surface light source, the peripheral light source 29 adopts LED lamp beads distributed in an annular shape, and the brightness of the central light source 28 and the brightness of the peripheral light; the light source 11 and the adjustable diaphragm 12 are both assembled in the casing 10, the adjustable diaphragm 12 is arranged at the light emitting end of the light source 11, the adjustable diaphragm 12 and the light source 11 are coaxially arranged, the outer wall of the casing 10 is rotatably connected with a diaphragm worm gear 15, the diaphragm worm gear 15 is connected with a handle 13 on the adjustable diaphragm 12, the handle 13 is driven to rotate through the rotation of the diaphragm worm gear 15, so that the position of a blade 14 on the adjustable diaphragm 12 can be adjusted to adjust the diaphragm aperture of the adjustable diaphragm 12, and the light emitting area of the light source 11 is controlled. The light emitting area and the intensity of the central light source 28 should meet the illumination light distribution requirements in a bright field directional reflection mode and a dark field mode; the diameter of the annular distribution of the LED beads of the peripheral light source 29 should be as small as possible, and it should be ensured that no obvious bright spot image of the LED beads is visible in the observation field of the camera at the photographing hole 8.

A driving mechanism is arranged in the box body 1, and the light source assembly 2 is driven by the driving mechanism to enable the light source 11 to move on a focal plane of the condenser lens 4; the driving mechanism comprises an assembly fixing frame 16 arranged in the box body 1, the light source assembly 2 is arranged on the assembly fixing frame 16, a screw 17 is screwed into a screw hole of the assembly fixing frame 16 and penetrates through the assembly fixing frame 16, namely the screw 17 penetrates through the assembly fixing frame 16 and is in rotary connection with the assembly fixing frame 16, two ends of the screw 17 are in rotary connection with the inner wall of the box body 1, and a first sliding rod 30 and a second sliding rod 31 both penetrate through the assembly fixing frame 16 and then are connected with the inner wall of the box body 1, so that the assembly fixing frame 16 can slide along the first sliding rod 30 and the second; the screw 17 is connected with a first worm gear 18, a first servo motor 19 and a first worm 20 connected with the first servo motor 19 are arranged on the inner wall of the box body 1, a second servo motor 21 and a second worm 22 connected with the second servo motor 21 are arranged on the assembly fixing frame 16, the first worm 20 is rotationally connected with the first worm gear 18, the second worm 22 is rotationally connected with the diaphragm worm gear 15, the first servo motor 19 drives the first worm 20 to rotate, the first worm 20 drives the first worm gear 18 and the screw 17 to rotate, and the screw 17 drives the assembly fixing frame 16 to slide along a first slide rod 30 and a second slide rod 31, so that the light source 11 in the light source assembly 2 can move on a focal plane of the condenser lens 4; and the second servo motor 21 drives the second worm 22 to rotate, and the second worm 22 drives the diaphragm worm wheel 15 to rotate, so that the light transmission aperture of the adjustable diaphragm 12 is changed, namely the light emitting area of the light source 11 is changed.

The embodiment of the utility model provides a working process:

as shown in fig. 9, the bright field directional reflection fingerprint appears when the light source 11 emits light: moving the assembly fixing frame 16 to place the center of a central light source 28 in the light source assembly 2 at the focus of a condensing lens 4, adjusting an adjustable diaphragm 12 to be as large as the central light source 28, turning on a light source 11 to enable the central light source 28 to emit light, converging light emitted by the light source assembly 2 through the condensing lens 4 to form approximate parallel light, transmitting the light through a spectroscope 3 to almost vertically irradiate a fingerprint object at a material detection hole 7, enabling the surface of a smooth plane object at the material detection hole 7 to be equivalent to a mirror, enabling reflected light to still be approximate parallel light, reflecting the reflected light through the spectroscope 3 to enter an imaging objective lens 5 at the side, reflecting the reflected light to a photographic hole 8 through a first reflecting mirror 6, and finally imaging through a camera to show a light-colored background of a bright field; under the irradiation of light emitted by the light source assembly 2, reflected light of the fingerprint lines on the fingerprint object and the background patterns on the lower layer of the object surface has scattering property, light rays which are finally reflected by the spectroscope 3 and enter the camera at the photographing hole 8 to form images are relatively less, the fingerprint lines are shown as dark lines with lower brightness than light background, and the background patterns are weakened; on the premise of not increasing the total height of the device, compared with the optical path length of the reflected light of the fingerprint object directly reaching the top of the device in the traditional spectroscope transmission imaging method, the optical path of the imaging optical path reaching the top of the device after being reflected twice by the spectroscope 3 and the first reflector 6 is greatly prolonged, the light flux of the fingerprint line and the reflected light of the lower-layer background pattern on the surface of the object entering the camera at the photographic hole 8 along with the extension of the optical path is greatly reduced because the reflected light of the surface of the smooth plane object is approximate parallel light, and the light flux entering the camera at the photographic hole 8 along with the extension of the optical path is reduced little, so the contrast between the fingerprint line and the light-colored background is larger and the background pattern is better weakened due to the extension of the optical path of the imaging optical path; the light transmission aperture of the adjustable diaphragm 12 is adjusted to further reduce the illumination intensity of the fingerprint lines and the background pattern on the lower layer of the object surface, and the brightness of the central light source 28 is adjusted until the appearance effect of the fingerprint lines is optimal.

As shown in fig. 10, dark field directional reflection fingerprints appear in the light emitting state of the light source 11: the setting of each parameter of the bright field directional reflection fingerprint is consistent with that of the bright field directional reflection fingerprint in the first embodiment, the bright field directional reflection fingerprint image is firstly displayed, the peripheral light source 29 is turned on, the adjustable diaphragm 12 is enlarged, the fingerprint object is irradiated by the light emitted by the peripheral light source 29 in the aperture of the adjustable diaphragm 12, the central light source 28 is turned off, the central light source 28 does not emit light, and the dark field directional reflection fingerprint image can be displayed in the camera at the photographic hole 8. Due to the turning off of the central light source 28, the parallel light vertically irradiating the smooth plane object is lost, so that the turned off central light source 28 is imaged as a dark background of a dark field; the fingerprint lines on the object are irradiated by the light emitted by the peripheral light source 29, the reflected light has scattering property, the light rays which enter the camera at the photographic hole 8 for imaging are relatively more, and the fingerprint lines are expressed as light-color lines with higher brightness than the dark-color background. Compared with the traditional dark field light distribution method, the LED lamp beads distributed annularly on the peripheral light source 29 replace a single point light source, and the incident angle of the incident light of the fingerprint object is smaller due to the smaller annular distribution diameter of the LED lamp beads, so that dark field imaging of the fingerprint has no bright spot interference, the line illumination is uniform, the contrast is better, and the brightness of the peripheral light source 29 is further adjusted until the fingerprint line showing effect is optimal.

As shown in fig. 9, the dark field fingerprint appears when the light source 11 is emitting: the setting of various parameters displayed by the bright field directional reflection fingerprint in the first embodiment is kept consistent, a bright field directional reflection fingerprint image is displayed firstly, the center of the central light source 28 is deviated from the focus of the condenser 4 by moving the light source assembly 2, so that light emitted by the light source assembly 2 is converged by the condenser 4 to become approximately parallel light, the approximately parallel light is obliquely irradiated to the fingerprint object at the material inspection hole 7 through the spectroscope 3, and due to the inclination of the irradiation angle, the approximately parallel light reflected by the surface of the smooth plane object is reflected by the spectroscope 3 and finally reaches the camera at the photographic hole 8, so that the imaging of the surface of the smooth plane object is a dark background of a dark field; under the irradiation of oblique approximately parallel light, the reflected light of the fingerprint lines on the object has scattering property, the light rays entering the camera at the photographic hole 8 are relatively more, the fingerprint lines are expressed as light-color lines with higher brightness than dark-color background brightness, the incident angle of the incident light is changed by further moving the position of the light source assembly 2, the clear aperture of the adjustable diaphragm 12 is adjusted, and the brightness of the central light source 28 is adjusted until the appearance effect of the fingerprint lines is optimal.

Example two

As shown in fig. 4 to 8, the reflection imaging portable fingerprint camera device includes a case 1, a light source assembly 2, a beam splitter 3, a condenser 4, an imaging objective 5, a first reflective mirror 6, a material inspection hole 7, a photographing hole 8 and a second reflective mirror 9, wherein light emitted by a light source 11 of the light source assembly 2 is reflected by the second reflective mirror 9 and transmitted through the beam splitter 3 to form an illumination light path, light reflected by the irradiated fingerprint object located at the material inspection hole 7 is reflected by the beam splitter 3 to form an imaging light path, the photographing hole 8 is externally connected with a camera (not shown in the figure), specifically, the light source 11 is arranged on the side of the second reflective mirror 9, the imaging objective 5 and the first reflective mirror 6 are arranged on the side of the beam splitter 3 in sequence, the top of the case 1 directly above the first reflective mirror 6 is the photographing hole 8, the second reflective mirror 9 is arranged on the illumination light path between the light source 11 and the condenser 4, the optical distance between the condenser 4 and the light source 11, the spectroscope 3 and the first reflector 6 respectively form an included angle of 45 degrees with the optical axis of the imaging objective lens 5, and collimation of an imaging light path is ensured.

The light source assembly 2 is arranged at the top in the box body 1, the light source assembly 2 further comprises a shell 10 and an adjustable diaphragm 12, the adjustable diaphragm 12 is in the prior art, details are not repeated in the patent, the light source 11 can adopt a single light source or a combined light source, and can be arranged according to specific conditions, in the first embodiment of the patent, a combined light source is adopted as the light source, the prior art is adopted, namely, the combined light source is formed by combining a central light source 28 and a peripheral light source 29, the central light source 28 adopts a surface light source, the peripheral light source 29 adopts LED lamp beads distributed in an annular shape, and the brightness of the central light source 28 and the brightness of the peripheral light; the light source 11 and the adjustable diaphragm 12 are both assembled in the casing 10, the adjustable diaphragm 12 is arranged at the light emitting end of the light source 11, the adjustable diaphragm 12 and the light source 11 are coaxially arranged, the outer wall of the casing 10 is rotatably connected with a diaphragm worm gear 15, the diaphragm worm gear 15 is connected with a handle 13 on the adjustable diaphragm 12, the handle 13 is driven to rotate through the rotation of the diaphragm worm gear 15, so that the position of a blade 14 on the adjustable diaphragm 12 can be adjusted to adjust the diaphragm aperture of the adjustable diaphragm 12, and the light emitting area of the light source 11 is controlled. The light emitting area and the intensity of the central light source 28 should meet the illumination light distribution requirements in a bright field directional reflection mode and a dark field mode; the diameter of the annular distribution of the LED beads of the peripheral light source 29 should be as small as possible, and it should be ensured that no obvious bright spot image of the LED beads is visible in the observation field of the camera at the photographing hole 8.

A driving mechanism is arranged in the box body 1, and the light source assembly 2 is driven by the driving mechanism to enable the light source 11 to move on a focal plane of the condenser lens 4; the driving mechanism comprises an assembly fixing frame 16 arranged in the box body 1, the light source assembly 2 is arranged on the assembly fixing frame 16, a screw 17 is screwed into a screw hole of the assembly fixing frame 16 and penetrates through the assembly fixing frame 16, namely the screw 17 penetrates through the assembly fixing frame 16 and is in rotary connection with the assembly fixing frame 16, two ends of the screw 17 are in rotary connection with the inner wall of the box body 1, and a first sliding rod 30 and a second sliding rod 31 both penetrate through the assembly fixing frame 16 and then are connected with the inner wall of the box body 1, so that the assembly fixing frame 16 can slide along the first sliding rod 30 and the second; the screw 17 is connected with a first worm gear 18, a first servo motor 19 and a first worm 20 connected with the first servo motor 19 are arranged on the inner wall of the box body 1, a second servo motor 21 and a second worm 22 connected with the second servo motor 21 are arranged on the assembly fixing frame 16, the first worm 20 is rotationally connected with the first worm gear 18, the second worm 22 is rotationally connected with the diaphragm worm gear 15, the first servo motor 19 drives the first worm 20 to rotate, the first worm 20 drives the first worm gear 18 and the screw 17 to rotate, and the screw 17 drives the assembly fixing frame 16 to slide along a first slide rod 30 and a second slide rod 31, so that the light source 11 in the light source assembly 2 can move on a focal plane of the condenser lens 4; and the second servo motor 21 drives the second worm 22 to rotate, and the second worm 22 drives the diaphragm worm wheel 15 to rotate, so that the light transmission aperture of the adjustable diaphragm 12 is changed, namely the light emitting area of the light source 11 is changed.

The second reflective mirror 9 realizes angle adjustment through a rotating mechanism; the rotating mechanism comprises a reflector fixing frame 23, the second reflector 9 is fixed on the reflector fixing frame 23, the reflector fixing frame 23 is connected with a second worm wheel 24 through a reflector rotating shaft 27, two ends of the reflector rotating shaft 27 are rotatably connected with the inner wall of the box body 1, a third servo motor 25 and a third worm 26 connected with the third servo motor 25 are arranged in the box body 1, the third worm 26 is rotatably connected with the second worm wheel 24, the third servo motor 25 drives the third worm 26 to rotate, and the third worm 26 drives the second worm wheel 24 to rotate, so that the angle of the second reflector 9 is adjustable. Similarly, when the position of the blade 14 on the adjustable diaphragm 12 is adjusted to adjust the diaphragm aperture of the adjustable diaphragm 12, and further control the light emitting area of the light source 11, the light emitting area and the intensity of the central light source 28 should meet the illumination light distribution requirements in the bright field directional reflection mode and the dark field mode; the diameter of the annular distribution of the LED beads of the peripheral light source 29 should be as small as possible, and it should be ensured that no obvious bright spot image of the LED beads is visible in the observation field of the camera at the photographing hole 8.

The embodiment of the utility model provides a second working process:

as shown in fig. 9, the bright field directional reflection fingerprint appears when the light source 11 emits light: moving an assembly fixing frame 16 to place the center of a central light source 28 in a light source assembly 2 at the focus of a collecting mirror 4, rotating a second reflecting mirror 9 to enable the optical axis of the second reflecting mirror 9 and the collecting mirror 4 and the axial lead of the light source assembly 2 to respectively form 45 degrees, adjusting an adjustable diaphragm 12 to be as large as the central light source 28, turning on a light source 11 to enable the central light source 28 to emit light, enabling light emitted by the light source assembly 2 to be reflected by the second reflecting mirror 9 and converged by the collecting mirror 4 to form approximately parallel light, transmitting the light to a spectroscope 3 to almost vertically irradiate a fingerprint object at a material detection hole 7, enabling the surface of the smooth plane object at the material detection hole 7 to be equivalent to a mirror, enabling reflected light to be still approximately parallel light, entering an imaging objective 5 at the side after being reflected by the spectroscope 3, then being reflected to a photographic hole 8 through a first reflecting mirror 6, and finally being imaged through a; under the irradiation of light emitted by the light source assembly 2, reflected light of the fingerprint lines on the fingerprint object and the background pattern on the lower layer of the object surface has scattering property, light rays reflected by the spectroscope 3 and finally entering the camera at the photographic hole 8 are relatively less, the fingerprint lines are shown as dark lines with lower brightness than light background, and the background pattern is weakened, so that on the premise of not increasing the total height of the device, compared with the optical path length of the reflected light of the fingerprint object in the traditional spectroscope transmission imaging method directly reaching the top of the device, the optical path of the reflected light reaching the top of the device after twice reflection by the spectroscope 3 and the first reflector 6 is greatly prolonged, and the light flux of the reflected light of the fingerprint lines and the background pattern on the lower layer of the object surface is greatly reduced along with the extension of the optical path in the camera at the photographic hole 8; the reflected light from the smooth planar object surface is approximately parallel light, and the light flux entering the camera at the photographic aperture 8 is reduced little along with the extension of the optical path. Therefore, the contrast between the fingerprint lines and the light background is larger and the background pattern is better weakened due to the extension of the optical path of the imaging optical path; the light intensity of the fingerprint ridges and the underlying background pattern on the object surface can be further reduced by adjusting the clear aperture of the adjustable diaphragm 12, and the brightness of the central light source 28 is adjusted until the appearance effect of the fingerprint ridges is optimal.

As shown in fig. 10, dark field directional reflection fingerprints appear in the light emitting state of the light source 11: the setting of each parameter of the bright field directional reflection fingerprint appearing in the second embodiment is kept consistent, the bright field directional reflection fingerprint image is firstly shown, the peripheral light source 29 is turned on, the adjustable diaphragm 12 is enlarged, the fingerprint object is irradiated by the light emitted by the peripheral light source 29 in the aperture of the adjustable diaphragm 12, the central light source 28 is turned off, the central light source 28 does not emit light, and the dark field directional reflection fingerprint image can be shown in the camera at the photographic hole 8. Due to the turning off of the central light source 28, the parallel light vertically irradiating the smooth plane object is lost, so that the turned off central light source 28 is imaged as a dark background of a dark field; the fingerprint lines on the object are irradiated by the light emitted by the peripheral light source 29, the reflected light has scattering property, the light rays which enter the camera at the photographic hole 8 for imaging are relatively more, and the fingerprint lines are expressed as light-color lines with higher brightness than the dark-color background. Compared with the traditional dark field light distribution method, the LED lamp beads distributed annularly on the peripheral light source 29 replace a single point light source, and the incident angle of the incident light of the fingerprint object is smaller due to the smaller annular distribution diameter of the LED lamp beads, so that dark field imaging of the fingerprint has no bright spot interference, the line illumination is uniform, the contrast is better, and the brightness of the peripheral light source 29 is further adjusted until the fingerprint line showing effect is optimal.

As shown in fig. 9, the dark field fingerprint appears when the light source 11 is emitting: the setting of various parameters displayed by the bright field directional reflection fingerprint in the second embodiment is kept consistent, a bright field directional reflection fingerprint image is displayed firstly, the center of the central light source 28 is deviated from the focus of the condenser 4 by moving the light source assembly 2 or rotating the angle of the second reflector 9, so that light emitted by the light source assembly 2 is converged by the condenser 4 to become approximately parallel light, the approximately parallel light is obliquely irradiated to the fingerprint object at the material inspection hole 7 through the spectroscope 3, and due to the inclination of the irradiation angle, the approximately parallel light reflected by the surface of the smooth plane object is little reflected by the spectroscope 3 and finally reaches the camera at the photographic hole 8, so that the surface of the smooth plane object is imaged to be a dark background of a dark field; under the irradiation of oblique approximately parallel light, the reflected light of the fingerprint lines on the object has scattering property, the light rays entering the camera at the photographic hole 8 for imaging are relatively more, the fingerprint lines are expressed as light-color lines with higher brightness than dark background brightness, the incident angle of the incident light is changed by further moving the position of the light source assembly 2 or rotating the angle of the second reflector 9, the clear aperture of the adjustable diaphragm 12 is adjusted, and the brightness of the central light source 28 is adjusted until the appearance effect of the fingerprint lines is optimal.

To sum up, the utility model discloses a photographic arrangement obtains approximate parallel light through the cooperation of light source assembly 2 with condensing lens 4, compares greatly reduced the device overall height with traditional directional reflection grading method, has realized the miniaturization, on this basis, the light that the fingerprint object reflects under central light source 28 shines reaches photographic hole 8 after the twice reflection of spectroscope 3 and optical element with the function of reflecting light, has prolonged the optical path of formation of image light path, thereby the contrast of fingerprint line and object background in the greatly enhanced field oriented reflection mode, weaken or even eliminate the interference of object background pattern, can obtain the higher field oriented reflection fingerprint image of quality; the adjustable diaphragm 12 in the light source assembly 2 can control the light emitting area of the central light source 28, so that the area of the light-colored background outside the fingerprint area is reduced as much as possible, the illumination intensity of fingerprint lines and the lower-layer background pattern on the surface of the object is reduced, and the fingerprint image quality shown by bright field directional reflection is better; by turning off the central light source 28 of the light source assembly 2 and turning on the peripheral light source 29, a dark field directional reflection fingerprint image different from the traditional dark field light distribution method can be obtained, and the dark field directional reflection fingerprint image has no bright spot interference, uniform line illumination and better contrast; by moving the light source assembly 2 or changing the angle of the second reflective mirror 9, a dark field image of the fingerprint can be obtained. In addition, the spectroscope 3 is creatively utilized for reflection imaging, so that only one optical element with a light reflection function needs to be arranged in an imaging light path, and on the premise of not increasing the total height of the device, enough space can be ensured to be reserved between the first reflective mirror 6 and the photographic hole 8 for arranging optical devices with a magnification function, so that the defect that the optical zoom multiple of some cameras is low is overcome, and the fingerprint imaging is clearer.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (10)

1. Portable fingerprint camera device of reflection formation of image, include the box and set up in photograph hole on the box, be equipped with light source assembly, spectroscope in the box, light source assembly includes light source, its characterized in that: the light that the light source sent passes through the spectroscope forms the illumination light path, is located illumination light path end offer on the box be used for shining the fingerprint object examine the material hole, be located examine material hole department the light that the fingerprint object was shone the back reflection and is passed through the spectroscope reflection forms the formation of image light path, set up the optical element who has the reflection of light function on the formation of image light path, the photograph hole set up in the warp the light path after the optical element reflection is terminal on the box.

2. The reflection imaging portable fingerprint camera device according to claim 1, wherein: still be equipped with condensing lens, formation of image objective in the box, the condensing lens set up in the light source with between the spectroscope illumination light path, formation of image objective set up in the spectroscope with between the photographic hole the formation of image light path.

3. The reflection imaging portable fingerprint camera device according to claim 2, wherein: the optical distance between the condenser and the light source is the same as the focal length of the condenser, the optical element adopts a first reflective mirror, the imaging objective lens is arranged between the spectroscope and the first reflective mirror, and the spectroscope and the first reflective mirror are arranged at an included angle of 45 degrees with the optical axis of the imaging objective lens.

4. The reflection imaging portable fingerprint camera device according to claim 3, wherein: the photographic hole is arranged on the box body right above the first reflective mirror, the material inspection hole is arranged at the bottom of the box body, the spectroscope is arranged right above the material inspection hole, and the condenser lens and the light source are sequentially arranged on the illumination light path above the spectroscope.

5. The reflection imaging portable fingerprint camera device according to claim 4, wherein: the light source assembly further comprises a shell and an adjustable diaphragm, the light source and the adjustable diaphragm are assembled in the shell, the adjustable diaphragm is arranged at the light emitting end of the light source and coaxially arranged with the light source, a diaphragm worm wheel is rotatably connected to the outer wall of the shell, and the diaphragm worm wheel is connected with a handle on the adjustable diaphragm.

6. The reflection imaging portable fingerprint camera device according to claim 5, wherein: and a driving mechanism is arranged in the box body, and the light source assembly is driven by the driving mechanism to enable the light source to move on the focal plane of the condenser lens.

7. The reflection imaging portable fingerprint camera device according to claim 6, wherein: the driving mechanism comprises an assembly fixing frame arranged in the box body, the light source assembly is arranged on the assembly fixing frame, a screw rod penetrates through the assembly fixing frame and is connected with the assembly fixing frame in a rotating mode, two ends of the screw rod are connected with the inner wall of the box body in a rotating mode, a first sliding rod and a second sliding rod penetrate through the assembly fixing frame and then are connected with the inner wall of the box body, the screw rod is connected with a first worm wheel, a first servo motor and a first worm connected with the first servo motor are arranged on the inner wall of the box body, a second servo motor and a second worm connected with the second servo motor are arranged on the assembly fixing frame, the first worm is connected with the first worm wheel in a rotating mode, and the second worm.

8. The portable fingerprint camera device according to any one of claims 5 to 7, wherein: and a second reflecting mirror is further arranged in the box body and arranged on the illumination light path between the light source and the collecting mirror.

9. The reflection imaging portable fingerprint camera device according to claim 8, wherein: the second reflective mirror is adjustable in angle through a rotating mechanism.

10. The reflection imaging portable fingerprint camera device according to claim 9, wherein: the rotating mechanism comprises a reflector fixing frame, the second reflector is fixed on the reflector fixing frame, the reflector fixing frame is connected with the worm gear II through a reflector rotating shaft, two ends of the reflector rotating shaft are rotatably connected to the inner wall of the box body, the inner wall of the box body is provided with a servo motor III and a worm III connected with the servo motor in a three-phase mode, and the worm III is rotatably connected with the worm gear II.

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