CN201096958Y - Scanning lens with temperature compensation - Google Patents

Abstract

The utility model relates to a scanning lens with temperature compensation. The utility model comprises a compensating lens group and a common lens group fixed inside the lens tube, wherein the compensating lens group is at least composed of a lens of dn/dt less than minus three with positive focal power; the common lens group is composed of three to four lenses of dn/dt more than zero and dn/dt less than zero with negative focal power which is made of common optical material; the optical system Phi between the compensating lens group and the common lens group is equal to Phi one plus Phi two, and is required to meet the relation of Phi one / Phi two less than minus two, when the temperature is raised, Delta Phi one plus Delta Phi two is less than zero, when the temperature is reduced, Delta Phi one plus Delta Phi two is more than zero, among the formula, the Phi is the lens focal power, the Phi one is the focal power of the compensating lens group, the Phi two is the focal power of the common lens group, the Delta Phi first is the focal power variable quantity after the temperature of the compensating lens group is changed, and the Delta Phi two is the focal power variable quantity after the temperature of the common lens group is changed. Due to the adoption of the temperature compensation technology, the scanning lenses is reduced and maintains due performance due to being influenced by temperature, and can be applied wihtin the wide range of temperature variation, and the production cost is reduced.

Description

Scanning lens with temperature compensation

Technical field

The utility model relates to a kind of camera lens of camera head, relates in particular to a kind of scanning lens with technique for temperature compensation.

Background technology

Along with development of science and technology, the demand of equipment such as flat bed scanner, MFP is increasing, uses more and more widely, along with the development of the market demand, requirement to equipment is also constantly improving, and develops towards low-cost, volume direction little, in light weight, high quality of scanning.At this development trend, a lot of producers use the plastics movement to replace metal movement commonly used in the past, cost is low, volume is little, lightweight requirement though satisfied greatly, but other a series of problems of the thing followed have also produced, in the equipment use, because movement is the core component of sweep test, its temperature can raise along with the lengthening of service time, because of the thermal expansivity of plastics bigger, make sensor devices (CCD) big from change with the optimal imaging identity distance of camera lens, depart from the ideal image position, caused the quality of scanning of equipment to descend.Therefore, how under the situation of quality of scanning that makes scanning lens under the prerequisite that guarantees low cost, small size, can be compensated, just seem particularly important in temperature variation.

Summary of the invention

Goal of the invention of the present utility model is to overcome the defective of prior art and provides a kind of image that camera lens is scanned of realizing temperature compensation still to keep having the scanning lens with temperature compensation of performance.

Goal of the invention of the present utility model realizes by following technical proposal:

A kind of scanning lens with technique for temperature compensation comprises the compensation lens set and the common lens set that are fixed in the lens barrel, and the compensation lens set is made up of at least 1 eyeglass, and common lens set is made up of 3～4 eyeglasses, it is characterized in that:

What a, described compensation lens set adopted is lens materials dn/dt＜-3, has positive light coke simultaneously;

What b, described common lens set adopted is the ordinary optical material, and its dn/dt＞0 or dn/dt＜0 has negative power simultaneously;

Optical system φ between c, described compensation lens set and the common lens set=φ 1+ φ 2, must satisfy following relation: φ 1/ φ 2＜-2,

Δ φ 1+ Δ φ 2＜0 when temperature raises,

Δ φ 1+ Δ φ 2＞0 when temperature reduces,

In the formula: φ is the camera lens focal power,

φ 1 is compensation lens set focal power,

φ 2 is common lens set focal power,

Δ φ 1 is a power variation amount after the compensation lens set temperature variation,

Δ φ 2 is a power variation amount after the common lens set temperature variation.

Refractive index 1.58＜Nd＜1.7 of described compensation lens set, Abbe number Vd＞55.

Described compensation lens set is 1 curved month type positive lens.

Described common lens set is followed successively by 1 negative lens, 1 or 2 positive lenss, 1 negative lens.

Described common lens set is made up of whole glass mirror or glass mirror and glass lens.

Compared with prior art, the utility model has adopted technique for temperature compensation to camera lens, makes scanning lens under the situation of temperature variation, and the image that scans reduces temperature influence and still keeps due performance, and owing to can use in wide temperature range, production cost reduces.

Description of drawings

Fig. 1 is an optical texture synoptic diagram of the present utility model.

Fig. 2 be the utility model in the time of 20 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (consideration temperature compensation).

Fig. 3 for the utility model in the time of 20 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (not considering temperature compensation).

Fig. 4 be the utility model in the time of 0 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (consideration temperature compensation).

Fig. 5 for the utility model in the time of 0 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (not considering temperature compensation).

Fig. 6 be the utility model in the time of 40 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (consideration temperature compensation).

Fig. 7 for the utility model in the time of 40 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (not considering temperature compensation).

Fig. 8 be the utility model in the time of 60 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (consideration temperature compensation).

Fig. 9 for the utility model in the time of 60 ℃ 42 lines to every millimeter modulation transfer function theoretical modeling curve map (not considering temperature compensation).

Embodiment

Embodiment is described in detail the utility model again below with reference to accompanying drawing.

As shown in Figure 1, have the scanning lens of temperature compensation, its object space is in the left-most position of whole camera lens, and the right-most position as the side is in whole camera lens comprises the compensation lens set and the common lens set that are fixed in the lens barrel from the object side to the image side successively.

The compensation lens set is the glass mirror 1 with 1 curved month type positive lens of positive light coke, and must satisfy: dn/dt＜-3, and the refractive index Nd=1.62 of its eyeglass, Abbe number Vd=63.6 satisfies the requirement of refractive index 1.58＜Nd＜1.7, Abbe number Vd＞55.

Common lens set is the ordinary optical material with negative power, usually its dn/dt＞0 is (if use the material of dn/dt＜0 in positive lens, better effects if), common lens set is made up of whole glass mirror, from left to right be followed successively by 3,4,1 negative lenses 5 of 2,2 positive lenss of 1 negative lens, according to different resolving power requirements, middle 2 positive lenss can be merged into 1 positive lens (promptly compensating lens set is that 3 eyeglasses are formed).The eyeglass that present embodiment adopts is whole glass mirror, and 6 is the chip cover glass, and 7 is imaging surface.

The present embodiment camera lens must satisfy following condition:

(1) glass dn/dt＜-3 of compensation lens set employing, common lens set adopt ordinary optical glass, their dn/dt＞0, and concrete numerical value is as shown in table 1:

Table 1

	Material	dn/dt (-40～-20)	dn/dt (-20～0)	dn/dt (0～20)	dn/dt (20～40)	dn/dt (40～60)	dn/dt (60～80)
								The compensation group	S-PHM52	-3.6	-3.6	-3.6	-3.6	-3.6	-3.7
Common group	S-TIM25	2.6	2.7	2.8	2.9	3.1	3.3
								S-LAH65	4.2	4.4	4.5	4.7	4.8	5
	S-LAH65	4.2	4.4	4.5	4.7	4.8	5
								S-TIL27	3.1	3.2	3.2	3.3	3.3	3.3

Annotate: above coefficient is the variations in refractive index coefficient of dlight (0.5837 μ m).

(2) φ 1=0.057452＞0; φ 2=-0.02537＜0 φ, 1/ φ 2=-2.79 satisfies φ 1/ φ 2＜-2

Δ φ 1+ Δ φ 2=1.3456*10 in the time of (3) 0 ℃ ^-5Δ φ 1+ Δ φ 2＞0 when＞0 satisfied temperature reduces

Δ φ 1+ Δ φ 2=-1.36583*10 in the time of (4) 40 ℃ ^-5Δ φ 1+ Δ φ 2＜0 when＜0 satisfied temperature raises

Δ φ 1+ Δ φ 2=-2.813*10 in the time of (5) 60 ℃ ^-5Δ φ 1+ Δ φ 2＜0 when＜0 satisfied temperature raises

In the formula: φ is the camera lens focal power,

φ 1 is compensation lens set focal power,

φ 2 is common lens set focal power,

Δ φ 1 is a power variation amount after the compensation lens set temperature variation,

Δ φ 2 is a power variation amount after the common lens set temperature variation.

The scanning lens of application of temperature compensation technique has different design datas under the different temperatures situation:

Table 2

The face sequence number	Surface type	Radius-of-curvature	Center thickness	Nd/Vd	Logical light diameter
						OBJ	STANDARD	∞	206.758315		216
1′	STANDARD	6.510000	1.560000	1.62/63.6	6.36
						2′	STANDARD	14.890000	0.465239		5.34
3′	STANDARD	-43.700000	0.820000	167/32.1	5.08
						4′	STANDARD	10.751000	0.574584		4.26
STO	STANDARD	∞	0.140521		3.9
						6′	STANDARD	10.495000	4.500000	1.80/46.6	4.42
7′	STANDARD	∞	0.084190		6.24
						8′	STANDARD	-61.393000	2.810000	1.80/46.6	6.24
9′	STANDARD	-12.912000	1.569622		7.36
						10′	STANDARD	-4.939000	2.230000	1.58/41.5	7.5
11′	STANDARD	-16.000000	11.491239		10.5
						12′	STANDARD	∞	0.700000	1.52/64.1	24.8
13′	STANDARD	∞	1.300000		25.28
						IMA	STANDARD	∞	-		26.78

Its temperature compensation function (is example with 20 ℃/0 ℃/40 ℃/60 ℃) is the face form as follows

Annotate: supposition movement material is PC, ds/dt=67*10 ^-6(ds/dt is meant the polar expansion number when the movement material varies with temperature)

Focal length, best focal plane vary with temperature as shown in table 3:

Table 3

Temperature	Focal length EFL		Best focal plane position of camera lens and variation delta 1		The variation delta 2 that movement causes	Comprehensive camera lens and movement change the best image planes bias Δ in back
								Do not consider temperature compensation	Consider temperature compensation	Do not consider temperature compensation	Consider temperature compensation	Do not consider temperature compensation	Consider temperature compensation
	20℃	22.4013	22.3986	0		0	0							0	0
0℃					22.4036			22.3901	0.003	-0.011	-0.016	0.019	0.005
	40℃	22.3991	22.4072	-0.004		0.01	0.014							0.018	0.004
60℃					22.3971			22.4159	-0.007	0.015	0.032	0.039	0.017

Annotate: Δ=| Δ 1-Δ 2|

Fig. 2～Fig. 9 respectively in the time of 20 ℃, 0 ℃, 40 ℃, 60 ℃ 42 lines to every millimeter modulation transfer function curve map of considering compensating action and not considering compensating action.Fig. 2～3 are (20 ℃) modulation transfer function curve map under the normal temperature.From Fig. 4～9 as can be seen, no matter temperature raises is still reduced, and has considered that the best focal plane of camera lens of temperature compensation function and the bias of desirable image planes are less than the camera lens (the thick arrow of black is represented best focal plane) of not considering compensating action.

Claims (5)

1, a kind of scanning lens with temperature compensation comprises the compensation lens set and the common lens set that are fixed in the lens barrel, and the compensation lens set is made up of at least 1 eyeglass, and common lens set is made up of 3～4 eyeglasses, it is characterized in that:

What a, described compensation lens set adopted is lens materials dn/dt＜-3, has positive light coke simultaneously;

What b, described common lens set adopted is the ordinary optical material, and its dn/dt＞0 or dn/dt＜0 has negative power simultaneously;

Optical system φ between c, described compensation lens set and the common lens set=φ 1+ φ 2, must satisfy following relation: φ 1/ φ 2＜-2,

Δ φ 1+ Δ φ 2＜0 when temperature raises,

Δ φ 1+ Δ φ 2＞0 when temperature reduces,

In the formula: φ is the camera lens focal power,

φ 1 is compensation lens set focal power,

φ 2 is common lens set focal power,

Δ φ 1 is a power variation amount after the compensation lens set temperature variation,

Δ φ 2 is a power variation amount after the common lens set temperature variation.

2, the scanning lens with temperature compensation according to claim 1 is characterized in that refractive index 1.58＜Nd＜1.7 of described compensation lens set, Abbe number Vd＞55.

3, the scanning lens with temperature compensation according to claim 1 and 2 is characterized in that described compensation lens set is 1 curved month type positive lens.

4, the scanning lens with temperature compensation according to claim 1 and 2 is characterized in that described common lens set is followed successively by 1 negative lens, 1 or 2 positive lenss, 1 negative lens.

5, the scanning lens with temperature compensation according to claim 1 is characterized in that described common lens set is made up of whole glass mirror or glass mirror and glass lens.

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