CN2681156Y

CN2681156Y - Novel optical hand grain collecting instrument

Info

Publication number: CN2681156Y
Application number: CN 200320102184
Authority: CN
Inventors: 林金龙; 沈柱
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-03
Filing date: 2003-11-03
Publication date: 2005-02-23
Anticipated expiration: 2013-11-03

Abstract

The utility model discloses a hand grain collecting instrument comprising a light source 2, a parallel flat plate 1, flat mirrors 3 and 4, an imaging lens 5 and an imaging sensor 6. The utility model is characterized in that the hand grain is extracted by the parallel flat plate; the hand grain collecting surface of the parallel flat plate (the surface which is contacted with hands) and the image-forming ray transmission plane (the surface which is opposite to the hand grain collecting surface) are vertical with a light axis; the parallel flat plate, the flat mirrors, the imaging lens and the imaging sensor are respectively arranged on the ray road, namely, the light generated by the light source enters the flat plate 1 from the side, and total emission happens in the parallel flat plate. A part of rays scattered by hand grain lines are ejaculated by the other surface of the flat plate, and then enter the lens through the flat mirror, and at last the image is formed on the sensor.

Description

Novel optical lines of the hand Acquisition Instrument

Technical field

The utility model belongs to optical field.

Background technology

Along with the progress of society fast development of computer technology particularly, receive more and more many concerns based on the automatic identification system and the product of the lines of the hand (fingerprint and palmmprint), be widely used in many fields such as public security, social security, security protection and finance.Lines of the hand Acquisition Instrument is the input equipment of lines of the hand image in the automatic recognition system, and it directly influences factors such as the performance of recognition system and cost.Though occurred the semiconductor fingerprint sensor in recent years, because its unstable properties, problem such as serviceable life is short is not generally adopted.Still mainly adopt the optically detecting instrument in the lines of the hand recognition system at present.Fig. 1 is traditional optics lines of the hand Acquisition Instrument principle schematic.The light that is sent by light source 1 incides on the surface 2 of prism 3, and according to the optical principle of total reflection, the light that incides on the surface 2 penetrates from another surface 4 of prism 3 after reflection.When hand was arranged, the light generation scattering of watch face streakline contact position just can obtain the image of streakline in the beam projecting direction on surface 2.Object plane in this system (surface 2) and systematic optical axis out of plumb are non-coaxial systems, trapezoidal aberration occurs with camera lens direct imaging meeting.Can revise this aberration with compensating prism, but increase the complicacy of system, improve cost of products.In addition, because the prism volume is big, collecting device is difficult to miniaturization.

Summary of the invention

The purpose of this utility model is to address the above problem, and a kind of novel lines of the hand Acquisition Instrument is provided, and system does not simply have trapezoidal deformation.

Fig. 3 is a structure key diagram of the present utility model, and comprising parallel flat (hereinafter to be referred as flat board) 1, light source 2, level crossing 3, level crossing 4, imaging lens 5, imageing sensor 6, and they arrange on light path successively.Hand contacts with the surface of parallel flat 1, and the light that light source 2 sends, is diffused through after level crossing 3 and the 4 change light paths by lines of the hand contact portion generation diffuse reflection at planar surface, by camera lens 5 clear ridge alignment picture is become on cmos image sensor 6.The lines of the hand face of getting of system's middle plateform is vertical with optical axis 7 with the imaging transmission plane, and parallel flat 1, level crossing 3, level crossing 4, camera lens 5 and imageing sensor 6 constitute centered optical system.

Fig. 2 further illustrates characteristics of the present utility model.Light source 5 launches light in dull and stereotyped 1 from the side among the figure, because surface 2 and surface 4 are polished surfaces, total reflection takes place, and light can not penetrate from planar surface 2 and surface 4.When hand by surperficial 2 the time lines of the hand and surperficial 2 contact positions diffuse reflection appears, scattered light can be from the surface 4 penetrates.At this moment in surface 4 one sides, can obtain the ridge alignment picture that is illuminated by light source 5 by camera lens.Planar surface 2 and the surface angle between 4 is less than 2 °, with the rectangle that guarantees the lines of the hand of being gathered and trapezoidal distortion less than 0.1%.

The utility model optical system directly sees through dull and stereotyped capture, does not have trapezoidal deformation, and simplicity of design, cost are low, are convenient to realize miniaturization under the prerequisite that keeps picture quality.

Description of drawings

Fig. 1 is the principle schematic of traditional lines of the hand Acquisition Instrument

Fig. 2 is the utility model optical characteristics synoptic diagram

Fig. 3 is the utility model optical system structure synoptic diagram

Fig. 4 is the utility model exemplary construction synoptic diagram

Embodiment

Fig. 4 is the utility model exemplary construction synoptic diagram.Dull and stereotyped 1 window area is 14mm * 18mm, and the selection of material is the HWB850 infrared glass; Light source 2 is infraluminescence pipes of wavelength 930nm; The scattered light of streakline changes light path by level crossing 3 and 4 and is imaged onto on the cmos sensor 6 through camera lens 5; Cmos device adopts OV7141.

Claims

1. lines of the hand Acquisition Instrument, comprise parallel flat 1, light source 2, level crossing 3, level crossing 4, imaging lens 5, imageing sensor 6, it is characterized in that: described parallel flat 1, level crossing 3, level crossing 4, imaging lens 5 and imageing sensor 6 arrange on light path successively.

2. the lines of the hand Acquisition Instrument that requires as right 1 is characterized in that: parallel flat is got angle between lines of the hand face and imaging light transmission plane less than 2 °.

3. as the lines of the hand Acquisition Instrument of right 1 requirement, it is characterized in that: it is vertical with optical axis with imaging light transmission plane that parallel flat is got lines of the hand face.

4. the lines of the hand Acquisition Instrument that requires as right 1 is characterized in that: parallel flat 1, level crossing 3, level crossing 4, camera lens 5 and imageing sensor 6 formation centered optical systems.

5. as the lines of the hand Acquisition Instrument of right 1 requirement, it is characterized in that: the light incident side face of parallel flat is a polished surface with the side relative with it.