TWM345250U - Single f-θ lens used for micro-electro mechanical system (MEMS) laser scanning unit - Google Patents

Abstract

Single f-θ lens used for micro-electro mechanical system (MEMS) laser scanning unit, is a shape of meniscus type, and is formed by the lens in which the concaved surface faces towards to the side of the MEMS reflecting mirror. The single f-θ lens has a first optical surface and a second optical surface, and converts the mapped spots by scanning light at nonlinear relationship between the angle and the time of the MEMS reflecting mirror into the mapped spots by scanning light at the linear relationship between the rotating angle and the distance of the MEMS reflecting mirror. Meanwhile, focuses the scanning light on the target by calibrating itself, the purpose of the linear scanning effect and the high resolution scanning can be achieved while the specified optical condition of the single f-θ lens is satisfied.

Description

M345250 VIII. New Description: [New Technology Field] This is a monolithic ίθ lens for a microelectromechanical laser scanning device, especially for a microelectromechanical mirror that exhibits harmonic motion. A one-piece ίθ lens that corrects the angular variation of the sinusoidal relationship to achieve the linear scanning effect required by the laser scanning device. [Prior Art] At present, the laser scanning device LSU (Laser Scanning Unit) used in the laser beam printer LBP (Laser Beam Print) uses a high-speed rotating polygon mirror to manipulate the scanning action of the laser beam. (Laser beam scanning), as described in U.S. Patent No. 7,707,171, [S6377293, US 6,295,116, or as described in Taiwan Patent No. 1198966. The principle is as follows: a laser beam is emitted by a semiconductor laser, and a parallel beam is formed through a collimator and an aperture, and the parallel beam passes through a cylinder. After the cylindrical lens, the width on the Y-axis of the sub-scanning direction can be parallelly focused along the parallel direction of the X-axis of the main scanning direction to form a line (line image). ), and then projected onto a high-speed rotating polygon mirror. The polygon mirror is uniformly and continuously provided with a polygon mirror which is located substantially at or close to the focus position of the above-mentioned line imaging (1 i ne i mage ). The polygon mirror can be used to control the projection direction of the M345250 laser beam. When the continuous plurality of mirrors are high and a, the laser beam incident on the mirror can be extended at the same angular velocity in the parallel direction of the main sweep ( Angular VelQeity) onto a ίθ linear scanning lens. ί θ linear scanning lens system; ^ beside the polygon mirror, can be a single scanning lens or a two-piece lens structure. The function of the linear scanning lens is that the laser beam that is reflected by the mirror on the polygon mirror and incident on the lens can be focused into an elliptical spot and projected onto a photoreceptor drum. On the imaging surface), and meet the requirements of scanning linearity. However, the conventional laser sweeping device LSU has the following problems in use: (1) The rotary polygon mirror is difficult to manufacture and the price is not low, and the production cost of the LSU is relatively increased. (2) The polygon mirror must have the function of idle rotation (such as 40,000 rpm), and the precision requirement is high, so that the mirror surface γ-axis Lu width of the reflective surface on the general polygon mirror is extremely thin, so that one of the conventional LSUs needs to be added. Cylindrical mirror. The cylindrical lens is used to focus the laser beam through a cylindrical mirror into a line (a point on the Y-axis) and then project on the mirror of the polygon mirror, thereby increasing the component and assembly process. (3) The conventional polygon mirror must be rotated at a high speed (such as 4 rpm), resulting in a relatively high rotational noise, and it takes a long time for the polygon mirror to start from the start to the working speed, increasing the waiting time after power on. (4) In the assembly structure of the conventional LSU, the center axis of the laser beam projected onto the polygon mirror is not the center axis of the polygon mirror, so that when the 6 M345250 is designed with the f0 lens, it is necessary to consider the polygon mirror. Off-axis deviation (deviation) problem, relative increase f (9 lenses are troublesome in design and manufacture. In recent years, in order to improve the conventional LSU assembly structure, an osci 1 latory MEMS reflection has been developed on the market. MEMS mirror, which replaces the conventional polygon mirror to control laser beam scanning. The microelectromechanical mirror has a reflective layer on the surface of the torsion oscillators, which can be oscillated by the oscillating reflection layer. The light is reflected and scanned, and in the future it can be applied to an imaging system, a scanner or a laser printer (laser scanning unit, LSU). (Scanning efficiency) - will be higher than the traditional rotating polygon mirror. For example, US Patent No. 6,844, 95, US 6, 956, 597 ' generates at least one driving signal, The driving frequency approaches the resonant frequency of the complex MEMS mirror and drives the MEMS mirror with a drive signal to generate a scan path, US 7,064,876, US 7,184,187, US 7,190,499, US2006/0033021,

US2007/0008401, US2006/0279826; or Taiwan patent TW M253133, which is connected between the collimating mirror and the f0 lens in an LSU module structure, and replaces the conventional rotary polygon mirror with a microelectromechanical mirror to control the laser The direction in which the beam is projected; or as in the Japanese patent jp 2006-201350. The microelectromechanical mirror has the advantages of small components, fast rotation speed, and low manufacturing cost. However, since the microelectromechanical mirror receives a voltage drive, it will make a simple harmonic motion, and the simple harmonic motion is a sinusoidal relationship between time and angular velocity, and is projected on the microelectromechanical reflection M345250 mirror, and its reflected reflection The relationship between the angle θ and the time VII is: θ(ί) = θΞ ^ιη(2π·/·ί) (1) where: f is the sweep frequency of the MEMS mirror; Α is the life ” after the microelectromechanical mirror , the maximum scanning angle of one side, the beam of the field, therefore, at the same time interval ~, the corresponding amount of change in the opposite is not the same and is decreasing, one is positive with time, = degree (Sinusoidal) Relationship, that is, at the same time interval, the chord function changes to: Continuation,) = ^. Clock 1 (2 [/. 〇 - such as & factory (9), , the reflection angle is a non-狳 relationship; when this reflection When the light is projected at different angles in the Mim 4 deep object, the yang is subject to different angles, and the light spots generated by the same time interval are the same as the Ding. The separation is not due to the sinusoidal wave peak of the MEMS mirror. And the amount of change will increase or decrease with time, with the familiar facet ° The angle of rotation is different in motion. If you use the conventional laser scanning device (LSU) that is an isometric MEMS mirror, the oscillating relationship will be sinusoidal with time. Produced, 'correcting the amount of micro-computers, causing the laser light velocity projected on the imaging surface to produce a degree-variation phenomenon, resulting in imaging deviation on the imaging surface. Therefore, the laser scanning device composed of the sweeping mirror Referred to as micro-micro-scanning device (MEMS LSU), its characteristic is that laser light 2 is scanned by /electric laser scanning mirror, and the micro-electromechanical reflection of sweeping light at different angles can be used for micro-electromechanical laser scanning. The f0 lens of the device is developed in gray, so that it can be correctly imaged on the target, which will be required for the correction of the optical knife. 8 M345250 [New content] The purpose of this creation is to provide a single microelectromechanical laser scanning device. The chip f0 lens is composed of a single lens which is crescent-shaped and concave on the side of the microelectromechanical mirror, and can correctly image the scanning light reflected by the microelectromechanical mirror on the target object, and The linear sweeping effect required by the laser scanning device. Another object of the present invention is to provide a monolithic f0 lens for a microelectromechanical laser scanning device, which is used to reduce the spot projected on the target (spot) The object is to achieve an effect of improving the resolution. A further object of the present invention is to provide a monolithic ί θ lens of a micro-electromechanical lightning scanning device, which can be corrected in the main scanning direction due to the deviation of the scanning light from the optical axis. And the offset of the sub-scanning direction is increased, so that the spot formed on the photosensitive drum is deformed into an elliptical shape, and the size of each imaging spot is made uniform, thereby achieving the effect of improving the resolution quality. A monolithic fβ-film for creating a microelectromechanical laser scanning device is suitable for reflecting at least one light source that emits a laser beam, and reflecting the laser beam emitted by the light source into a scanning light with a total of 2 oscillations: a microelectromechanical mirror To image on the target; for a laser printer, this target is often a drum, that is, the laser beam to be imaged, selected by a microelectromechanical mirror: micro Electromechanical=shooting, reflecting the beam to form the stray light, and the material is shaped on the photosensitive drum after correcting the angle and position through the Μ(4). 'Because the photosensitive drum is coated with a photosensitizer, it can sense the toner on the paper, so The information is printed out. 9 M345250 - This monolithic f<9 lens contains a ―first-optical surface and a 7th 氺:pq' system will be a simple harmonic motion of the microelectromechanical mirror, on the imaging surface j”, f distance from the original The non-equal rate of increasing or decreasing or increasing the time; correcting the material rate scanning, causing the laser beam to scan at the image plane of the imaging surface and causing the scanning light to be shifted in the main scanning direction and the sub-scanning direction due to the offset optical axis The imaging deviation formed on the sensory beam is uniformized, and (4) the scanning light secret is concentrated on the target object. [Embodiment] Referring to the single-chip f0 lens of the present microelectromechanical laser scanning device shown in FIG. Schematic diagram of the optical path of the present invention. The monolithic f<9 lens 13 of the present microelectromechanical laser scanning device comprises a first optical surface and a second optical surface, which are suitable for a microelectromechanical laser scanning device. The MEMS laser scanning device mainly comprises a laser light source 11, a microelectromechanical mirror 10, a cylindrical mirror 16, two photodetectors i4a, 14b, and a target for sensitization. In the middle, the target system is implemented by a photosensitive drum 15. The light beam hi generated by the light source 11 passes through the cylindrical mirror 16 and is projected onto the microelectromechanical mirror 1 。. The microelectromechanical mirror 10 reflects the light beam 111 at different points in time to form a scanning light. 113a, 113b, 114a, 114b, 115a, 115b. The projection of the scanning rays 113a, 113b, 114a, 114b, 115a, 115b in the X direction is referred to as a sub scanning direction, and the projection in the Y direction is called The main scanning direction is the main scanning direction, and the scanning angle of the microelectromechanical mirror 1 is M345250 0c. Since the microelectromechanical mirror 10 exhibits a simple harmonic motion, its moving angle changes sinusoidally with time, as shown in Fig. 2. Therefore, the angle of incidence of the scanning light is nonlinear with time. As shown in the figure, the peak a-a' and the trough b-b' have a swing angle significantly smaller than the bands ab and a'-b', and the angular velocity The unequal phenomenon easily causes the scanning light to cause imaging deviation on the photosensitive drum 15. Therefore, the photodetectors 14a, 14b are disposed within the maximum scanning angle ±0c of the microelectromechanical mirror 10, and the angle is soil θρ, laser The beam 111 is reflected by the microelectromechanical mirror 10 from the peak of Fig. 2, which is equivalent to the scanning ray 115a of Fig. 1; when the photodetector 14a detects the scanning beam, it indicates the MEMS mirror 10 Swinging to +0P angle, this is equivalent to the scanning light 114a of Fig. 1; when the scanning angle of the microelectromechanical mirror 10 changes a point of Fig. 2, this time is equivalent to the position of the scanning light 113a; at this time, the laser light source 11 It is controlled to start emitting the laser beam 111, and when scanning to the point b of Fig. 2, this time corresponds to the position of the scanning light 113b (the laser beam 111 is emitted by the laser source 11 within a range of ±0 η); When the mirror 10 is oscillated, it is also controlled by the laser light source 11 to start emitting the laser beam 111 at the # band a'-b'; thus completing one cycle. Referring to Figure 3, there is an optical path diagram for scanning light through the f0 lens. Among them, ±0 n is the effective scanning angle, as shown in Figure 1. When the rotation angle of the microelectromechanical mirror 10 enters ±0η, the laser light source 11 starts to emit the laser beam 111 to be scanned, and is reflected by the microelectromechanical mirror 10 into the scanning light, and the scanning light passes through the f <9 lens 13 is rotated by the first optical surface and the second optical surface of the ίθ lens 13, and the distance reflected by the microelectromechanical mirror 10 is nonlinearly related to the time of the scan. 11 M345250 = fruit will be = focus on the photosensitive drum dr: The farthest into the optical center 2 = the distance between the electromechanical mirror 1G to the first optical surface, the d2 is the first ιΓ, the surface Hd3 is the second optical surface to the photosensitive drum

In the multi-test 4, after the scanning light is projected on the photosensitive drum, the light is incident on the photosensitive drum 15 after passing through the lens 13 in the direction of the sister. Since the angle incident on the f 0 mirror #13 is zero, the deviation in the main scanning direction is The shifting is zero, so that the spot 2a imaged on the photosensitive drum 15 is a circular shape. When the scanning light rays 113b and 113c are transmitted through the lens 13 and projected on the photosensitive drum 15, since the angle formed by the incident lens 15 and the optical axis is not zero, the offset rate in the main scanning direction is not zero, resulting in The projection length of the main scanning direction is larger than the light spot formed by the scanning light 111& the same is true in the sub-scanning direction, and the light spot formed by the scanning light deviating from the scanning light Ilia will also be larger; The spots 2b, 2c on the drum 15 are of a type of ellipse, and the areas of 2b, 2c are larger than 2a. Wherein, SaO and SbO are the lengths of the spot of the scanning light on the reflecting surface of the microelectromechanical mirror 1 in the main scanning direction (γ direction) and the sub scanning direction (X direction), and Sa and Sb are scanned on the photosensitive drum 15 The length of any one of the light spots formed in the γ direction and the χ direction. The 12 M345250 early film f 0 lens can correct the spot size through the distortion of the f θ lens 13 in the main scanning direction, so that the spot size is controlled within a limited range, and the light can be lighted in the sub-scanning direction. The dot size is corrected by the distortion of the ίθ lens 13, so that the spot size is controlled within a limited range, and the spot size distribution (the maximum spot to the minimum spot ratio) is controlled and controlled to an appropriate range to provide a match. Resolution. In order to achieve the above effects, the monolithic f0 lens is designed on the first optical surface or the second optical surface, and can be designed using a spherical surface or an aspheric surface. If an aspheric surface is used as the design, the aspheric surface is expressed by the following equation. Design: : Anamorphic equation z (Cx)X2+(Cy)Y2 1 + V1 - (1 + Kx){Cxf X2 - (1 + Ky)(Cy)2 Y2 + 4 [(1- for + (i+ 4 )r2 A[(i-a)x2 + (l + 5P)r2 f+c J(i - cP)z2 + (l+cP)r214 + DR[(l-DP)X2+(l^ DP)Y2] (2) where 'Z is the distance from the optical axis direction to the 0-point tangent plane at any point on the lens (SAG); Q and & respectively are the curvature of the X direction and the Y direction (curvature); & They are the Conic coefficient in the X direction and the Y direction respectively; 戽, A, G, and A are the conical deformation coefficients of the fourth, sixth, eighth, and tenth powers of the rotationally symmetric port ion, respectively. (deformation from the conic); 戽, 柝, and A, respectively, non-rotationally symmetric components are respectively four 13 M345250 times, six times, eight times, ten powers of cone deformation coefficient (deformati〇n from The co Nic); and 戽 is reduced to a single aspheric surface. 2: Toric equation z = zv+——^y)x2 1+ ^1-((3⁄4^)2 x2

Cxy =-i-- (1 / Cx) — Zy

Zy = (Cy)Y2 1 ++Ky)(Cy)2Y2 +baya + b6y6 + 58r8 + b10y10 (3) where Z is the distance from the optical axis direction to the tangent plane (SAG) of any point on the lens; G and Q is the curvature of the Y direction and the X direction respectively; the heart is the Conic coefficient of the Y direction; the 10,000, 10,000, and A are the coefficients of the fourth, sixth, eighth, and tenth powers ( 4th~10th order coefficients) deformation from the conic); and then simplified to a single sphere. In order to enable the scanning light to image on the target at an equal rate, that is, at the same time interval, the distance between the two spots is equal; the monolithic f Θ lens of the present invention can scan the light 113a to the scanning Between the inserted light beams 113b, the scanning light exit angle is corrected so that the two scanning rays of the same time interval are corrected by the exit angle, and the distances of the two light spots formed on the imaged photosensitive drum 15 are equal. Further, when the laser beam 111 is reflected by the microelectromechanical mirror 10, its spot is large. For example, if the scanning light passes through the distance between the microelectromechanical mirror 10 and the photosensitive drum 15, the spot will be larger, which is not in conformity. Practical resolution requirements; the monolithic ίθ lens of the present invention can further focus the scanning light 113a to the scanning light 113b reflected by the microelectromechanical mirror 10 to focus on the imaged photosensitive drum 15 to form a smaller spot; The monolithic f0 lens of the present invention can evenly equalize the size of the spot image formed on the photosensitive drum 15 (limited to a range that meets the resolution requirement) for the best resolution.

The monolithic f<9 lens of the present invention is formed by a crescent-shaped lens having a concave surface on the side of the microelectromechanical mirror, and has a first optical surface and a second optical surface' which reflects the angle and time of the microelectromechanical mirror 10. The scanning light ray spot of the nonlinear relationship is converted into a scanning ray spot whose distance is linear with time, and the scanning ray correction is condensed on the target; the microelectromechanical mirror 1 is 藉 by the monolithic ί θ lens 13 The reflected scanning light is imaged on the photosensitive drum 15; wherein the first optical surface and the second optical surface have at least one optical surface formed by aspherical surfaces in the main scanning direction; the first optical surface and the second optical surface are in the pair Sweeping money to the optical surface of the composition. Further advancement - in the optical effect of the monolithic Μ lens 13, the monolithic lens of the present invention further satisfies the condition of the formula (4) in the main scanning direction: (4) or, in the main scan Direction satisfies the formula (5) 0.05 <

Know factory 1) JY <0.5

15 M345250 and satisfy the formula (6) in the sub-scanning direction, 1<Ιΐ~^|<1〇·° (6) where 'fY is f<9 the focal length of the lens 13 in the main scanning direction, dg is θ=0 f (9 lens 丨 3 distance from the target side optical surface to the target, fs is the focal length of the monolithic f 0 lens 13 , and the radius of curvature of the Rix ith optical surface in the X direction; that is, the refractive index of the lens 13 (refraction) • index) ° In addition, the uniformity of the spot formed by the monolithic f 0 lens of this creation can be expressed as the ratio of the maximum spot to the minimum spot size of 5, that is, satisfying the formula (7): 0.2 < ^ = M^(Sb-Sa) (/) Further, the resolution of the monolithic ίθ lens of this creation can be obtained by scanning the light spot of the scanning light on the reflecting surface of the microelectromechanical mirror 1 The ratio of the maximum spot on the drum 15 (Rati〇〇f φ scanning 1 ight of maximum spot) and 77 min are the ratio of the spot of the scanning light on the reflecting surface of the microelectromechanical mirror 10 by the small spot on the target. (Ratio scanningf scanning light 〇f minimum spot) is expressed, which satisfies equations (9) and (1〇), max(^-5J ^max - ςτχ <;〇-25 \^b0 * ^a〇) (9) n min(Sb^Sa) ^7min Q< 〇·1 b0 %^a〇) (10) 16 M345250 where Sa and Sb are the photosensitive drum The direction of the light beam is the length of the light spot in the main scanning direction and the sub-scanning direction, 3 is the ratio of the minimum spot to the maximum spot on the photosensitive solid; SaQ Xiao Sb() is the scanning surface of the mirror of the microcomputer s mirror 10. The length of the light spot in the main scanning direction and the sub-scanning direction. ▼ In order to make this creation more clear and detailed, the following illustrations are used to describe the structure and technical features of the creation. The following examples are disclosed in the following. The main embodiment of the monolithic & μ lens of the device is described. Therefore, the embodiment disclosed below is applied to a two-electromechanical laser scanning device, but generally has a microelectromechanical laser scanning device. In addition to the monolithic mirror disclosed in this creation: the structure is a technique of notification, so in general, the artist knows that the MEMS components of the microelectromechanical laser are disclosed in this creation. It is not limited to the following: the structure of the embodiment, that is, the constituent elements of the lens of the microelectromechanical laser scanning, can be changed, modified, or modified, for example, the radius of curvature design or the surface shape is Equal spacing adjustments are not limited. °〇十材贝选, <First Embodiment> =(, spherical formula design; 4_= aspherical surface, using equation (2) is a non-spherical i brother; the second school surface is aspherical, the tenth is the first learning characteristic and The aspherical parameter 17 M345250 is as shown in Table 1 and Table 2. Table 1. Optical characteristics of f0 of the first embodiment

Fs=206.0 optical surface curvature radius (mm) d thickness (mm) nd refractive index (optical surface) (curvature) (thickness) (refraction index: MEMS reflective surface R(] 〇.〇〇〇〇〇〇35.00 1 lens 1 R1 (Ύ Toroid, 1.533 Rlx* • 23.736584 8.00 Rly* -53.745472 R2fAnamorphic>> R2x* -11.483665 202.54 R2y* -45.703682 Sense drum idrum^RS 〇.〇〇〇〇〇〇* indicates aspherical table II, Optical surface aspherical parameter optical surface of one embodiment Toric equation Coefficient Ky conic coefficient (Conic Coefficent) 4th power coefficient Order 6th power coefficient 8th power coefficient Order Order Coefficient 10th power factor Order Coefficient Coefficient (B4) Coefficient (B6) (B8) fB10) Rl* -2.209983 1.730E-06 -4.047E-10 -8.574E-14 0.000E+00

Ky Coefficient (Conic Coefficent) _0.000001 Kx Coefficient Coefficient (0.6655) R2* Anamorphic equation coefficent _ 4th power coefficient 6th power coefficient 8th power coefficient 10th power coefficient

Order Order Order Coefficient Order Coefficient

Coefficient (AR) Coefficient (CR) (DR)

9.880E-07 -2.494E-11_O.OOOE+OQ_O.OOOE+QO 4th power factor 6th power coefficient ~8th power factor 10th power factor Order Order Order Coefficient Order Coefficient

Coefficient (AP) Coefficient (BP) (CP) (DP) -4.660E-01 6.554E-01_0.000E+00 0.000E+00 The optical path of the optical surface of the monolithic f0 lens 13 thus constructed is as shown in the figure. 5. fX=34.432, fY=431.228 can convert the scanning light into a scanning light spot whose distance is linear with time, and scan the spot on the microelectromechanical mirror 10 by SaO=13·616 and SbO=3747·202 into scanning light. Focusing on the photosensitive drum 15 to form a smaller spot, and full 18 M345250 foot type (4) ~ type (10) strip ^ cow, to the right side of the description window 3 is estimated) ), as shown in Figure 6a (the center is symmetrically the same. Q 6, the left side of the window 3 and the ancient side axis spot size from 6^ (sweep table 3, the first embodiment satisfies the condition table % main scanning direction)

JY sub-scanning direction|(士士乂max(V\)^^^Lsb.sa) ^Sb〇-Sa0) S^b〇;Sa〇) 0.470 0. 255 9. 260 〇. 8150 〇.0873 〇. 0605 M345250 <Second Embodiment> The monolithic ίθ lens 13 of the present embodiment is a crescent-shaped lens having a concave surface on the side of the microelectromechanical mirror, and is aspherical on the first optical surface, using the formula (3) ) is designed for an aspherical formula; aspherical on the second optical surface, and aspherical formula using equation (2). Its optical properties and aspheric parameters are shown in Tables 4 and 5. Table 4, θθ optical characteristics of the second embodiment fs=206.0 '----- optical surface curvature radius (mm) d thickness (mm) nd refractive index (flexual) (curvature) (thickness) (refraction index, MEMS Reflective surface Rf] 〇.〇〇〇〇〇〇35.00 1 lens 1 R1 iY Toroid) 1.533 Rlx* -23.727889 8.00 Rly* -54.746066 R2fAnamorphic>) R2x* -11.477359 171.82 R2y* •45.969165 Luguang drum (^drum)R3 *Main two hail - 〇.〇〇〇〇〇〇* indicates aspheric

Table 5, optical surface aspherical parameters of the second embodiment optical surface (ring surface equation coefficient Toric equation Coefficient Ky conic coefficient (Conic Coefficent) 4th power coefficient Order 6th power coefficient 8th power coefficient Order Order Coefficient 10th power coefficient Order Coefficient Coefficient (B4) Coefficient (B6) (B8) (B10) Rl* -2.408220 -1.608E-06 -2.795E-10 -6.485E-14 0.000E+00 Lateral surface equation coefficient (Anamorphic Equation coefficent)_ 4th power coefficient 6th power coefficient 8th power coefficient 10th power coefficient Order Order Order Coefficient Order Coefficient Coefficient (AR) Coefficient (CR) (DR)

Ky Coefficent R2* _0.004530Kx Conic Coefficent 5.666E-07 -6.490E-11_0.000E+004th Power Coefficient 6Λ Power Coefficient ~8th Power Coefficient Order Order Order Coefficient Coefficient (AP Coefficient (BP) (CP) _0.000E+0Q l (Hh power factor Order Coefficient (DP) -0.617309 -2.637E-01 1.105E-01 0.000E+00_0.000E+00 20 M345250 The optical path of the optical surface of the monolithic f0 lens 13 is shown in Fig. 7. fX= 34. 406, fY= 413. 661 converts the scanning light into a scanning light spot whose distance is linear with time, and the microelectromechanical mirror 10 glazing point Sa0= 13. 64, Sb0=3720. 126 scanning becomes scanning light, focusing on the photosensitive drum 15, forming a smaller spot, and satisfying the conditions of (4)~(10), as shown in the table 3. The spot size is distributed from the central axis 7 to the right side of the scanning window 3: light spot 8a (center axis), 8b~8 j (scan window 3 right side), as shown in Fig. 8; The side and the right side # are the same as the symmetry. Table 6. The second embodiment satisfies the condition table 0. 415 0. 265 9. 267 0.6962 0.0874 0.0609 ^3 Λ Main Direction described -1)

JY sub-scanning direction-----)fs

Klx Κ2χ

s=min(SrSa) max〇V5J =max(VK) 7max_(5). · Meaning. ) = min〇V&)

Vmin ~' /cc , \^bO ' ^a〇) 21 M345250 <Third Embodiment> The one-piece lens 13 of the present embodiment is composed of a crescent-shaped lens on the electromechanical mirror side, at the first The optical surface is a non-spherical formula design; the second optical surface is aspherical, = 1 = is an aspheric formula. Optical characteristics and aspherical parameters Table VII, f0 optical characteristics of the third embodiment

£1 (Y Toroifl) Rlx* Rly* R2(AnamorphiV) R2x* R2y* Lu Guang Drum (ώτιττΛΐη 1.533 23.541873 -55.680207 -11.458304 -46.094282 〇.〇〇〇〇〇〇8.00 171.04 * indicates aspherical table VIII, third The optical surface aspherical parameter optical surface of the embodiment is a ring image equation coefficient Toric equation Coefficient Ky cone coefficient (Conic CoefFicent) 4Λ power coefficient 6di power coefficient 8th power coefficient Order Order Order Coefficient Coefficient (B4) Coefficient (B6) (B8) 10Λ power factor Order Coefficient (B10) _ Rl* -2.973693 -1.538E-06 0.000E+00 0.000E+00 0.000E+00 Anamorphic equation coefficent Ky conic coefficient (Conic Coefficent) 4th power coefficient 6Λ power factor 8th power coefficient Order Order Order Coefficient 10th power coefficient Order Coefficient Coefficient (AR) Coefficient (CR) (DR) R2* -0.136363 2.049E-07 0.000E+00 0.000 E+00 0.000E+00 Round Miscellaneous Potential 4th Power Coefficient 6th Power Coefficient 8th Power Coefficient 10th Power Coefficient Kx 11^ Le· . Order Order Order Coefficient Orde r Coefficient (Come Coefficent) c〇effident (Ap) c〇efflcient (BP) (CP) (DP) -0.607418 3.101E-01 0.000E+00 0.000E+00_0.000E+00 22 M345250 The optical path of the optical surface of the slice ίθ lens 13 is shown in Fig. 9. f(l)Y= 4831.254, f(2)Y= -559.613 can convert the scanning light into a scanning light spot whose distance is linear with time, and On the microelectromechanical mirror 10, the light spot 8 & 0 = 14.488, 81) 0 = 2800.64 scans into scanning light, and focuses on the photosensitive drum 15 to form a smaller spot 'and satisfies (4) to (10). The condition is as shown in Table 3; the spot size is distributed from the central axis 9 to the right side of the scanning window 3: the light spot 10a (center axis), 10b~10 j (the rightmost side of the scanning window 3), as shown in Fig. 10; _ The left side of the window 3 is the same as the symmetry on the right side. Table IX, the third embodiment satisfies the condition table 0.434 0. 279 9. 228 0.6982 0.0904 0.0631 ^3 Λ Main scanning direction -1)

JY sub-scanning direction----)/5 ^Ιλ: ^2jc min〇V&) max(^ -Sa)

Two max〇V&) V max ~ cxy^bO 9 ^a〇) =min(V&) 23 M345250 <Fourth Embodiment> The monolithic f0 lens 13 of the present embodiment is crescent-shaped and concave The lens on the side of the microelectromechanical mirror is composed of aspherical surface on the first optical surface, aspherical formula using equation (3), aspherical surface on the second optical surface, and aspherical formula using equation (2). Its optical properties and aspheric parameters are shown in Tables 10 and 11. Table 10, f0 optical characteristics of the fourth embodiment fs=198.0 Optical surface curvature radius (mm) d thickness (mm) nd refractive index (optical surfac (curvature) (thickness) (refraction index) MEMS reflection a 〇.〇〇〇 〇〇〇35.00 1 lens 1 R1 (Ύ Toroid) 1.533 Rlx* -24.990718 8.00 Rly* -39.175002 R2fAnamorphic) R2x* -11.478512 153.43 R2y* -38.860737 Drum idrum 〇.〇〇〇〇〇〇* indicates aspherical surface

24 M345250 Table 11. Eleventh, fourth embodiment, optical surface aspherical parameter, optical surface ring image, surface equation coefficient, Toric equation Coefficient (optical surface), Ky cone coefficient, 4th power coefficient (Conic Coefficent), Order Coefficient, 6th power factor, Order Coefficient, 8th Power Coefficient Order Coefficient HHh Power Coefficient Order Coefficient Rl* 0.163632 1.619E-07 1.036E-10 0.000E+00 0.000E+00 Anamorphic equation coefficent Ky cone coefficient 4th power coefficient 6th power Coefficient 8th power coefficient 10th power coefficient (Conic Coefficent) Order Coefficient Order Coefficient Order Coefficient Order Coefficient R2* -0.076067 3.896E-07 4.789E-11 0.000E+00 0.000E+00 Kx conic coefficient 4th power factor (Conic Coefficent) Order Coefficient 6th Power Coefficient Order Coefficient 8tii Power Coefficient Order Coefficient 10th Power Coefficient Order Coefficient -0.618399 -5.831E-01 0.000E+00 0.000E+00 0.000E+00 The monolithic f0 formed by this The optical path of the optical surface of the lens 13 is shown in Fig. 11. fX=33.431, fY=938.65 can convert the scanning light into a scanning light spot whose distance is linear with time, and scan the spot on the microelectromechanical mirror 10 SaO=11288, SbO=3517.812 into scanning light, in the photosensitive drum 15 Focusing on, forming a smaller spot, and satisfying the conditions of (4)~(10), as shown in Table 3; the spot size is distributed from the central axis 11 to the right side of the scanning window 3: spot 12a (center Axis), φ 12b~12j (the rightmost side of the scanning window 3), as shown in Fig. 12; the left and right sides of the scanning window 3 are the same symmetry. 25 M345250 Table 12, the fourth embodiment meets the condition table 0. 163 0. 112 9. 327 0.6150 0.0942 0.0579 d3 Λ Main scanning direction -1)

Sub-scanning direction δ

minU) max(Sb -Sa) two maxQVi) (^bO * ^aO ) minU) By the above embodiment, the creation can at least achieve the following effects: (1) The monolithic f (9 lens) by the present creation The setting can adjust the non-equal rate scanning phenomenon of the microelectromechanical mirror in the simple harmonic motion on the imaging surface from the non-equal rate scanning phenomenon which is decreased or increased with time, and is corrected to the equal-rate scanning, so that the laser beam is on the imaging surface. The projection is equal-rate scanning, so that the distance between two adjacent spots formed on the target is equal. (2) By the setting of the monolithic lens of the present invention, the distortion can be corrected in the main scanning direction and the sub-scanning direction to scan the light. The light spot on the target focused on the image is reduced. (3) By the setting of the monolithic lens of the present invention, the distortion can be corrected in the main scanning direction and the sub-scanning direction to scan the light, so that the image is imaged on the object. The size of the spot is uniform. 26 M345250 The above-described preferred embodiments are merely illustrative and not limiting; the technical and technical personnel defined by the skilled person in the present invention Can be within the scope of protection Yan Gengren will be in the creation of this creation [simplified description of the schema] #目1 is the creation of a single-piece "photograph of the optical path of the lens; Figure 2 is a microelectromechanical mirror scanning angle 0 and time t Off®·ffi 3 is an optical path diagram and symbol illustration of the scanning light passing through the first lens and the second lens; FIG. 4 is a schematic diagram showing the change of the spot area with the projection position after the scanning light is projected on the photosensitive drum. Figure 5 is a light path diagram of the first embodiment; Figure 6 is a light path diagram of the first embodiment; Figure 7 is a light path diagram of the second embodiment; Figure 8 is a light spot diagram of the second embodiment; FIG. 10 is a light path diagram of the third embodiment; FIG. 11 is a light path diagram of the fourth embodiment; and FIG. 12 is a light spot diagram of the fourth embodiment. 27 M345250 The main components represent the symbol description] 10 · Photosensitive drum; 11: Laser light source; ill: Laser beam; 113a, 113b, 113c, 114a, 114b, 115a, 115b: Scanning light; 13: f0 lens; 14a, 14b : Photoelectric detector; Lu 15: Photoconductor drum; 16: Cylindrical 2, 2a, 2b, 2c: light spot; 3 · effective scanning window; 5, 7, 9, 11: central axis; 6, 8, 10, 12: 0·lmm analytical circle (Geometrical Spot); 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h: spot; 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h, 8i, 8j · · spot; 10a, 10b, 10c, lOd, lOe , lOf, lOg, lOh, lOi, 10 j : Φ light spot; and 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j: light spot. 28

Claims (1)

M345250 IX. Patent application scope: a monolithic lens of a micro-electromechanical laser scanning device; the system is suitable for a micro-electromechanical Lerin drawing device, and the hybrid electromechanical device includes at least - for emitting light weight, and - to resonate Wei's beam reflection f is a microelectromechanical mirror of the scanning wire, and is used for the object; the monolithic ίθ lens is composed of a crescent-shaped concave mirror on the side of the microelectromechanical mirror, with - The first optical surface and the second optical surface can convert the angle of the reflection of the microelectromechanical mirror with the time nonlinear non-linear scanning light spot into a distance and the color of the scanning light, and can scan the light The correction is concentrated on the target; the scanning light reflected by the microelectromechanical mirror is imaged on the target by the monolithic f θ lens. 2. The monolithic μ lens according to item i of the patent application further satisfies the following conditions in the main scanning direction: 〇 < ~ < 0.6 JY where /4 is the focal length of the monolithic (7) lens in the main scanning direction It must be θ=ο° the distance from the optical surface of the lens target to the target. 3. The monolithic μ lens described in claim 1 further satisfies the following conditions: satisfies in the main scanning direction: <0.5 and satisfies the direction of the sub-study: 0.05 < knows the factory" Jy 0.1 < <10.0 29 M345250 is the focal length of the monolithic ί θ lens in the main scanning direction, ^ the focal length of the monolithic ί θ lens 曲率 the radius of curvature of the optical surface in the 乂 direction; m is the refractive index of the monolithic f0 lens . 4. If the single-lens lens described in item i of the patent application scope, the ratio of the large spot to the minimum spot size satisfies: 02<S^^^S〇l max〇V\) ^中' Sa and Sb are the lengths of any spot formed by the scanning light on the photosensitive drum in the main scanning direction and the secondary sweeping direction, and 5 is the ratio of the domain level to the maximum spot. The single lens according to claim 1, wherein the ratio of the maximum spot on the target to the minimum spot on the target is satisfied. Job (~Λ.) min(V^J (A〇.D <0.25 <0.1 where Sa. and Sb. The spot for scanning the light on the reflecting surface of the MEMS mirror in the main scanning direction and vice The length of the scanning direction, Sa and Sb are the lengths of any one of the light spots formed by the scanning light on the photosensitive drum in the main scanning direction and the sub-scanning direction, and 77 max is the spot of the scanning light on the reflecting surface of the microelectromechanical mirror. The ratio of the maximum spot on the target scanned, the ratio of the spot of the scanned light on the reflecting surface of the MEMS mirror scanned to the minimum spot on the target.