CN200950180Y

CN200950180Y - Curve tilting mirror device for laser scanner

Info

Publication number: CN200950180Y
Application number: CN 200620025163
Authority: CN
Inventors: 范志新; 李志广
Original assignee: Hebei University of Technology
Current assignee: Hebei University of Technology
Priority date: 2006-01-18
Filing date: 2006-01-18
Publication date: 2007-09-19
Anticipated expiration: 2016-01-18

Abstract

The utility model relates to a curved tilting mirror applied on a laser scanner, a plane mirror having regular-polyhedron shape substituted by gear-wheel shape and having a vibration mirror system of a tilting mirror substituted by a special curved mirror. Unilateral and approximately translational scan of laser beam is achieved, the scanning speed is even, signal synchronizing can be achieved more easily, and geometric distortion and other defects of the scanning of a plane mirror are overcome. The utility model can be applied under special condition that light beams are required to make translational scan of laser TV, laser online check and other laser scanners, etc.

Description

Rotating mirror device with curved surface for laser scanner

Technical field

The utility model relates to a kind of rotating mirror device with curved surface for laser scanner, realize hot spot is done the scanning of unidirectional intimate translation with simple design proposal, can be in laser television, laser is used widely in various laser scanners fields such as X-ray inspection X and bar-code identification.

Background technology

Laser television is because colour gamut is wide, and color saturation height, picture dimension flexibility and changeability are easy to control, and characteristics such as no electromagnetic radiation radiation can be widely used in open-air large-scale image and show teaching demonstration, fields such as back projection display apparatus.Laser television occupies special status in the demonstration field, and all planned research of carrying out laser television of many in the world countries has had remarkable progress now.The scanning system that Germany laser display technology company produces is by scanning written image line by line fast in whole viewing area, being exactly the line scanning that obtains horizontal direction with 25 body catoptrons of speed rotation that per second 1250 changes, is the field scan that 50Hz, 60Hz or 100Hz realize vertical direction with the frequency with galvanometer then.The three primary colours that Changchun Inst. of Optics and Fine Mechanics, Chinese Academy of Sciences adopts RGB DPL solid state laser to show as colour, proposition has non-spot scan imaging laser technology---the zonule scanning projection imaging of complete independent intellectual property right, adopt ripe face battle array spatial light electrical addressing modulation technique, realize pixel gating and intensity modulation simultaneously, overcome all drawbacks of single pixel point by point scanning, realized no interference noise, light field is even, efficiency of light energy utilization height, cost is low, the laser display that is suitable for producing in batches, realized that 60 inches laser full color videos show, showed that color is beautiful, the coloured image of high saturation, and declared multinomial domestic and international patent.

At present, most laser televisions all are to adopt multiple surface rotating mirror to realize scanning, and the galvanometer deflector drives galvanometer and realizes scanning, and adopt the advantage of this scan mode to be: scanning angle is big, good beam quality, image resolution ratio height.But this scan mode requires very strictness to the machining precision and the control accuracy of tilting mirror, and this also is one of technical difficulty of realizing the laser display television image.The laser television gordian technique mainly contains: scan-synchronized, solid-state laser and laser crystal.At present, laser scanning mainly contains: modes such as mechanical rotating mirror-galvanometer system scanning, galvanometer scanning, the scanning of humorous galvanometer and holoscan.Wherein the scanning of mechanical rotating mirror-galvanometer system because of the precision height, scan angle is big, optical loss is little, be suitable for that scanning, strong anti-interference performance, the speed of gyration of various wavelength is fast, simple in structure intuitively to be extensive use of.There is intrinsic horizontal scanning mirror field geometric distortion in the laser scanner scan mode of tilting mirror-galvanometer system, cause hot spot on galvanometer, it is the non-linear and non-time symmetry of direction of line scan translational speed on the screen on plane, cause shielding the distortion of picture, the centre of light distribution is strong on the screen, inhomogeneous some defectives that wait that both sides are weak.

The utility model content

The purpose of this utility model is to propose a kind of rotating mirror device with curved surface for laser scanner, can overcome the defective of prior art.The utility model adopts curved reflector gear-like structure with simple design proposal, the regular polygon structure that replaces tilting mirror-galvanometer system, make hot spot do intimate translation scan, overcome some defectives of tilting mirror-galvanometer system, obtain to use in the occasion that needs laser beam to do translation scan.

The rotating mirror device with curved surface for laser scanner that the utility model provides is a curved reflector gear-like structure, and the gear centre rotating shaft is connected with the driving micromotor.

" tooth " of gear-like curved surface tilting mirror is made up of the sunny side and the back, and sunny side is a curved reflector, and the back is the plane of no-mirror.The curved surface profile curvilinear equation is: y=ax ^k, a is a constant in the formula, power exponent k is a non-integer, and between 1 and 2, can be unrestricted, the true origin of x and y is at the crown place in the formula, and the y coordinate is along the tooth radius opposite direction, and the x coordinate is along the vertical radial direction in crown place.Tooth radius is R, and thickness is L, and the number of teeth is N, and folded light beam translation distance between gear is H.

The gear centre rotating shaft is connected with the driving micromotor.The slope of the initial incidence point of light beam is close on the slope at the crown place of a tooth and the flank of tooth of next tooth, and during the entire emission face rotated, the slope at laser incidence point place differed very little, and it is very little that the folded light beam direction is changed.

Light path principle of the present utility model is described below: laser beam incides on the gear-like curved reflector with certain angle, and folded light beam is pointed to other specific direction.When the gear-like curved reflector rotates, because special curve form, make curved surface when incident light moves (or oppositely moving), though the incidence point on curved surface has changed, folded light beam is along with having changed, but the direction of folded light beam is constant substantially, only does approximately parallel moving.The gear-like structure can make folded light beam realize simple scanning.

The utility model can be in laser television, and laser is used on various laser scanners such as X-ray inspection X and bar-code identification.

Compared with the prior art the utility model has following advantage:

1) owing to light path design of the present utility model, folded light beam is done approached parallel mobile scanning.

2) because structural design of the present utility model can make the sweep velocity of folded light beam more even, greatly reduce the difficulty of signal Synchronization.

3) because structural design of the present utility model, can make the sweep velocity of folded light beam more even, overcome the non-linear and asymmetry that the geometric distortion of plane mirror rotating mirror system scanning field brings, make that light intensity is more evenly distributed on the screen.

Description of drawings

Fig. 1 is a light path synoptic diagram of the present utility model.

Fig. 2 is a local coordinate system on the tooth of the present utility model.

Embodiment

Specify as follows in conjunction with the accompanying drawings:

As shown in Figure 1,1 incident beam, 2 folded light beams, 3 curved surface minute surfaces.

Be taken into irradiating light beam and reflecting curved surface normal angle 45 degree, direction right-to-left, folded light beam and surface normal angle are 45 degree equally, and direction from up to down.The tooth radius unit of being made as 1, i.e. R=1, thickness L=0.2 (can be unrestricted), number N of teeth=8, the incident beam direction is 0.7071 to the center of rotation distance, and each curved mirror is 36 degree in the face of center of rotation institute subtended angle degree, and folded light beam is translation distance H=0.2 between gear.Set up local coordinate system on a tooth, true origin is at the crown place, the y coordinate along tooth radius in the other direction, the x coordinate is along the vertical radial direction in crown place, the face shape contour curve of a flank of tooth OA section, as shown in Figure 2.Curved surface profile curvilinear equation derivation principle is: light beam jumps on the next flank of tooth when some from a crown, and the incidence point of the crown and the flank of tooth has close slope, and a flank of tooth rotates 45 degree, and the slope variation of laser incidence point is smaller on the flank of tooth.As crown place slope is 1 (miter angle), and the slope of getting initial incidence point on the flank of tooth is 0.9 (42 degree angle), is y=0.84x so obtain the curvilinear equation of a concrete expression curved surface profile ^1.58

When the gear-like curved reflector rotates, folded light beam is done parallel moving roughly thereupon, and the light beam that incides crown can jump on the next flank of tooth at once.Like this, when the gear uniform rotation is got up, folded light beam just can scan by uniform translation.For wheel footpath R=1, the situation of number N of teeth=8, the translation distance H=0.2 of scanning light beam, the angle of divergence of scanning light beam can be controlled at the scope of about 6 degree.For the situation of N＞8, the wheel footpath is constant, reduces the translation distance of scanning light beam, gives the curvilinear equation that makes new advances, and then the angle of divergence of scanning light beam can be controlled at littler angular range.

Optical element processing of the present utility model can be to add the system polishing with high density aluminium ingot car to form, and adopts contemporary precision digital process technology, as long as provide the toroidal function form, level of processing can be accomplished fully.Also can be to process by the mode of pasting acrylic thin plate plating minute surface on model of gear surface, can also be that the plating mirror finish forms after assembling of bend glass catoptron or the optical plastic injection moulding.

The utility model is according to the needs of sweep velocity and translation distance, the concrete parameter of design gear shape curved reflector laser scanner, and as tooth radius, the number of teeth and curved surface profile curvilinear equation etc.Use the utility model can design the new pattern laser TV,, replace tilting mirror-galvanometer laser scanner with a pair of gear-like curved reflector laser scanner.Design speed curved reflector fast, that translation distance is big is as line scanning, and rotating speed curved reflector a little slower, the translation distance point scans as Frame, constitutes the ratio of 16: 9 or 4: 3.The scan image composing images generator of laser modulation signal plays and digital micro-mirror (DMD) or the suitable effect of liquid crystal over silicon (LCOS), projects to giant-screen through optical projection lens and gets on, and realizes that laser television shows.Because the scan mode of parallel mobile beam of the present utility model, line scan speed is even, and signal Synchronization is become easily, has overcome the distortion that the geometric distortion of horizontal scanning mirror field causes shielding picture and has waited some defectives.The occasion that the utility model requires laser beam to do translation scan in the online detection of laser and other fields also has potential application prospect.

Claims

1, a kind of rotating mirror device with curved surface for laser scanner is characterized in that: described curved surface tilting mirror is a curved reflector gear-like structure, and the gear centre rotating shaft is connected with the driving micromotor.

2, rotating mirror device with curved surface for laser scanner according to claim 1, it is characterized in that: " tooth " of described gear-like curved surface tilting mirror is made up of the sunny side and the back, sunny side is a curved reflector, and the back is the plane of no-mirror, and the curved surface profile curvilinear equation is:

y＝0.84X ^1.58

The true origin of x and y is at the crown place in the formula, and the y coordinate is along the tooth radius opposite direction, and the x coordinate is along the vertical radial direction in crown place.

3, rotating mirror device with curved surface for laser scanner according to claim 1 is characterized in that:

Described tooth radius is R, the unit of being taken as 1, i.e. R=1; Gear thickness is L, and L=0.2 can be unrestricted; The gear number of teeth is N, N=8; Folded light beam translation distance between gear is H, H=0.2; The gear centre rotating shaft is connected with the driving micromotor.