JPS58220136A - Optical device enabled to change magnification - Google Patents

Abstract

PURPOSE:To simplify the constitution of the titled device and to improve assembling, by interlocking the zooming of lenses in a lens barrel with the movement of a lens barrel fitting board relationally by using a cam. CONSTITUTION:The titled device consists of pins 51, 52 turned downward fitted to inner tubes 13, 14 supporting the 1st and 2nd lenses 11, 12 of the lens barrel 7, slit holes 49, 50 formed on the wall of the lens barrel 7, and the 2nd moving means to zoom the lenses 11, 12 in the lens barrel 7 by a cam plate 54 related to the pins 51, 52 optionally slidable in the direction of optical axis. When the 1st pulley 32, a driving pulley, is turned normally by a prescribed angle in accordance with the selected magnification, a lens barrel fitting board 24 is reciprocated along a rail 22 and the lens barrel 7 is shifted in the 1st fixing mirror 6 direction or the 2nd fixing mirror 8 direction in the moving trace of an inclined direction (a) corresponding to the inclination angle alpha of the rail 22 from the optical axis between the 1st and 2nd fixing mirrors 6, 8.

Description

[Detailed description of the invention] The present invention relates to a variable magnification optical device in an image forming apparatus.

In particular, the present invention relates to improvements in variable-power optical devices using variable focus lenses.

Figure 1 shows a very schematic configuration of an example of an image forming apparatus (electronic copying machine) that uses a variable focus lens as an optical system and incorporates a variable magnification optical device. A variable magnification optical device using a lens and image forming process equipment are built-in. 2 is disposed on the top plate of the machine box 1, and is driven back and forth in the left-right direction on the top plate of the machine box 1 by means of a original document table glass. The original 0 is placed on the original table glass 21 with the image to be copied facing downward, and is set by covering the original pressing plate 6t.

Thus, the downward image surface of the original O set on the document glass 2 is formed on the top plate of the machine box in a direction substantially perpendicular to the direction of movement of the document glass 20 during the forward or backward movement of the document glass 2. When passing through the 4th slit hole, it is sequentially illuminated by the illumination lamp 5. The reflected light from the document surface of the illumination light is driven to rotate in the direction of the arrow around the axis 10 along the path from the first fixed mirror 6 to the lens bowl portion 7 incorporating the variable focus lens to the second fixed mirror 8. The original image is incident on the surface of the photosensitive drum 9 and formed into an image, and slit exposure of the original image is performed on the surface of the photosensitive drum 9. Although not shown in the figure, image forming process equipment according to various known principles and methods is arranged around the surface of the photosensitive drum 9, and the exposure of the original image described above and the action of the process equipment on the photosensitive drum 9 cause the image forming process to form on the drum surface. A toner image corresponding to the original image is formed, the toner image is transferred and fixed onto a transfer material, and the transfer material is discharged outside the machine as a copy.

Copying at the same size, enlargement, and reduction is done using the copier operation panel (not shown)
By operating the magnification setting device located above, the projection magnification of the optical system that forms and projects the original image onto the surface of the photosensitive drum 9, and the correlation between the original scanning speed V□ and the photoreceptor circumferential speed V2 can be adjusted. f
1-m (m is the selected magnification). Further, the operating conditions of other necessary image forming process equipment are automatically converted to those suitable for the selected copying magnification and executed. Here, the conversion of the projection magnification of the optical system is limited to υ, which will be described in detail below.
Lυ is made so that the position of the first or second fixed mirror is shifted in one direction and a zooming movement of the lens in the variable focus lens barrel 7 is performed.

Figures 2 to 4 show an example of a wire-type lens drive mechanism that is subject to modification in the present invention. Figure 2 is a vertical side view of the lens barrel 7, and Figure 6 is a lens barrel shift and focal length adjustment. FIG. 4 is a plan view of the m-rotating mechanism, and is a front view (Idemitsu @) of the lens barrel 7 in FIG. 6.

In the lens barrel 7 of this example, the lens 11 and the second lens 12, which are fitted and held in the inner tubes 13 and 14, respectively, are housed in the barrel, and the inner tubes 13 and 14 of the first and II2 lenses are respectively fitted into and held by the inner tubes 13 and 14. It is free to move in the optical axis direction within the lens barrel and is also free to rotate. Reference numeral 15 denotes a focal length adjustment element which is rotatably fitted onto the lens barrel 7 and prevents movement of the lens barrel 7 in the axial direction. 16 and 17 are respectively formed in the upper wall of the lens barrel 70 in the circumferential direction, and are first and second slit cam holes, and 18 is a focal length adjustment ring IEID, which partially extends in the direction of the first slit cam hole 16. A nine-linear slit cam hole is formed on the surface of the protruding small plate 151 in the direction of the lens barrel axis, and is intersecting with the first slit cam hole 16 of the lens barrel 71M. Reference numeral 19 denotes a linear slit cam hole formed in the circumferential barrel of the focal length adjustment 3J115 in the lens barrel axis direction, and intersecting with the second slit cam hole 17 of the lens barrel 7111. Reference numeral 20 denotes a pin which is installed on the upper outer surface of the inner cylinder 1.5 that holds the 11-karat gold lens, and has a first slit cam hole 16 on the lens barrel 7 side and a ring protruding small plate 151.
It is located at the intersection of the slit cam holes 18 of the fill and engages with both cam holes 16 and 18. 21 is the second lens 12
The second slit cam hole 17 of the lens barrel 71Q and the ring circumferential jli19A are
Both cam holes 17 are located at the intersection of the slit cam holes 19.
・It is engaged with 19.

Therefore, when the focal length adjustment source 15 is rotated clockwise or counterclockwise with respect to the lens barrel 7 in the O configuration, it moves slowly and is held by the second lens 11 and the second lens 12. The inner cylinders 15 and 14 are connected to the cam holes 16 and 18, 17 and 1, respectively.
9 and the pins 20 and 21, it is rotated within the lens barrel 7 and driven to move in the axial direction of the lens barrel. That is, the lenses 11 and 12 in the lens barrel are subjected to zooming movement (change in the air distance between the lenses) in relation to each other, and the focal length changes.

In Fig. 3, 22 is the optical axis 16 between the first and second fixed mirrors 6 and 8) - (with respect to 83, it is at the common placement reference position on the document platen glass 2 at any copying magnification. The side edge of the next placed document is imaged at the same position as the side edge of the photoreceptor drum 9, and a predetermined angle α of 1,000 planes is maintained, and both ends are attached to the machine box via the holders 26□ and 23□. A rail 24 is immovably mounted and supported by an inner O fixing member (not shown), and left and right columns 27 and 24 are respectively installed on the rail 22 on the side of the stand 24.
2B with screws 29 and 60, the axis of the xDe lens barrel 7 is aligned with the optical path axis f between the first and second fixed i-lars 6 and 8.
6) Parallel to -f8J, it is held immobile with the next attitude.

62 is a drive pulley (first pulley) fixedly supported by a vertical drive shaft 61 on the side opposite to the D overhanging side with the rail 22 inside, and filters 6 and 64 are vertically mounted on both ends of the rail 22, respectively. The second and third pulleys are freely rotatable around the shafts 35 and 56t, and 67 is a stand tension wire for attaching the lens barrel. Wrap it several times around the first pulley 32, which is suspended from the drive pulley by the primary i.
Next, it is hung around the third pulley 64 at φ and the other end 37□ is locked to the stand 24.

Therefore, as the drive pulley 32 rotates forward and backward,
is applied to the tensile shear wire 67 and is driven to move along the rail 22 by receiving a tensile force in the direction of the second pulley 33 or the third pulley 64. The tp lens barrel 7 is the first and second
Optical path axis between fixed mirrors 6 and 8 open mirrors +6) −
(With respect to 8J, it is shifted in the direction of the first fixed mirror 6 or the direction of the second fixed mirror 8 along a movement locus in an oblique direction a corresponding to the inclination angle α of the rail 22.

68 is a drive pulley that is concentric with the first pulley 62 and the first
A fourth goo IJ (6 having a different diameter from the first pulley 62), 39, which is integrated with the pulley 62, is supported by the shaft 65 of the second pulley 65 so as to freely rotate concentrically with the pulley 7? : 5th pulley, 4
0, the lens barrel is installed upright at the base @ (rail engagement @) of the base 24, and as soon as it is supported freely to rotate on the round shaft 41, pulley 6, and 42 fix the base to the 24 surface of the O base near the sixth pulley 40. Bracket 4 is placed in a diagonally upward position and is disposed toward the lens barrel 7 side.
3, a seventh pulley held freely rotatable about the shaft 44;
45 is! 1!3 pulley 34c This is an eighth pulley that is freely rotatably supported by one shaft 36 and concentric with the pulley.

46 is focal length system! The wire 46 is endless and rotates from the fourth pulley 68 to the fifth pulley 39 to the sixth pulley.
Pulley 40 → circumference of focal length adjustment ring 15 → seventh pulley 4
It is suspended in the order of 2→8th pulley 45→4th pulley 38. Note that the wire 46 is wound several times around the fourth pulley 68 and the focal length adjustment @15o cylinder.

That is, the first to sixth pulleys 32 to 34 described above. wire 37
When mounting the lens barrel, the fourth pulley 38, which has a diameter different from that of the first pulley 2, is integrated with the first pulley 62 as the base 24 is moved in the direction of the first fixed mirror 6 or in the direction of the second fixed mirror 8. Because they rotate synchronously, the focal length adjustment ring 15 of the lens barrel 7 can be rotated clockwise or counterclockwise by the differential between the base 24 and the wire 46 (the IJ differential between the base 24 movement system and the ring 15 rotation system). As a result, the lenses 11-12 in the lens barrel 7 perform zooming movements to change the focal length, and the image of the document is selected by the photoreceptor and formed at a specific magnification.

The lens barrel is mounted on the base 24 and the focal length adjustment item 15 is the first pulley 52t which is a drive pulley according to the selected copying magnification. Move to the desired position and rotate to the appropriate rotation angle.

In the φ-order optical system, when a general single lens is used as the imaging lens system, if the lens is moved to obtain the magnification t-X, the optical path length from the original to the focusing surface must be changed accordingly. , when the above-mentioned variable focus lens is used as the imaging lens, the imaging position at each magnification is determined by the focal length Mt
- Can be corrected by changing.

Figures 5 and 6 show an example in which the rotation shape of the ring rotation wire 46 for the focal length adjustment 1 steepness 15 is different from that shown in Figure 6.4. A sixth pulley 40 and a seventh pulley 4 are installed on the left and right sides, respectively, with the lens barrel 7 placed inside the stand 24.
2 is freely rotatable around shafts 41 and 44, and the wire 46 from the fifth pulley 39 is connected to the sixth pulley 40 - the seventh pulley 42 → the focal length adjustment ring 150 of the lens barrel 7 (clockwise direction). Winding several times) - 6th Boo IJ 8th
This is directed toward pulley 45. Or 5th pulley 3
The wire 46 from 9 is suspended along the path of the sixth gooley 40 → the circumference of the focal length adjustment ring 15 of the lens barrel 7 (wrapped several times in the counterclockwise direction) → the seventh pulley 42 - ψ16 boo IJ 40. 8
It may be directed toward the pulley 45. However, in this case, the # of the base 24 of the focal length adjustment ring 15 and the direction of rotation thereof are different from those in the above case.

The wire hanging configuration shown in FIGS. 5 and 6 is more effective than the wire hanging configuration shown in FIG.
- Although there are advantages such as the parallel relationship between the optical path axes (6) and (8) between the optical path axes (6) and (8) being always stably maintained, the explanation thereof will be omitted since it is outside the main point of the present invention.

By the way, in both the example shown in Fig. 6.4 and the examples 5 and 6, the lens moving means within the variable focus lens barrel 7, that is, the lens zoom moving means within the lens barrel is complicated, and assembly is difficult due to the wiring. Bad nature, -! Focal length due to wire elongation/shift etc. #'J! It was impossible to prevent the rotational deviation error of the J alignment ring 15.

In view of the above, it is an object of the present invention to eliminate the above-mentioned drawbacks of a variable-power optical device using a variable focus lens, and to move a lens barrel and zoom a lens within the barrel with a simple configuration. 6.

That is, the present invention is a variable-focus optical device f using a variable focus lens.
In 〃, the first moving means for moving the variable focus lens barrel according to the 7S magnification and the second moving means for zooming the lens inside the lens barrel are formed separately, and the first The gist of the present invention is a variable magnification optical device (t) characterized in that the first moving means operates in conjunction with a cam mechanism when the moving means is driven.

FIG. 7 1d-I shows an overall plan view of an embodiment of the variable magnification optical device of the invention, in which the first moving means moves the variable focus lens barrel 7 in accordance with variable magnification. That is, the shift means for the barrel 7 is mounted on the base guide rail 22, similar to the pigeon house shown in FIG. 3 or 5. 1st to 3rd pulleys 32 to 64. A mechanism consisting of a pull wire 37 was utilized.

As shown in the vertical cross-sectional side view in FIG. 8, the vJ variable focal length lens barrel 7 has a second lens 12 fitted and held in the inner tubes 13 and 14, respectively, as in the case of the example in FIG. The inner cylinders 16φ14 of the first and second lenses are each freely movable in the optical axis direction (6) (81) within the lens barrel 7. Downward pins 49 and 50 are integrally installed, and slit holes are formed on the lower surface of the lens barrel 7 on the left and right sides of the pin 47 in the axial direction of the lens barrel, respectively. These pins 51 and 52 are pins installed downward on the lower surfaces of the lens barrel 16 and f<2 lens inner barrel 14, respectively.
It engages with the slit holes 49 and 5D formed in the lower surface 1 of the lens barrel 7, and its tip protrudes outward from the lens barrel 7. $2 In contrast to the example shown in Figure 2, this lens barrel is not equipped with a focal length adjustment ring 15.

To attach the lens barrel, there are 9 holes on the surface of the stand 24 as shown in FIG. 9(a).
A slit hole 53 in the optical path axis direction is located approximately at the center 7 of the table 24.
Shape! The five downward protruding pins 47, 51, and 52 on the bottom surface of the lens barrel are mounted on the base 24 of the lens barrel 7.
The arm plates 25 and 26 on the left and right sides of the lens barrel are inserted into the slit hole 56 in the optical path axis direction, and the arm plates 25 and 26 on the left and right sides of the lens barrel are connected to the left and right supports 27 and 28 on the table 24 side, as in the case of the apparatus shown in FIGS. 6 and 5. screw 29
- By stopping at 60, it is firmly attached to the stand 24.

The lens barrel supplement described in 54-1 is a cam plate that is horizontally elongated in the direction of an angle of 11'λ to the optical path axis and supported by a sliding guide rail plate 55 on the lower side of the stand 24. As shown in FIG. 9(b), a first cam groove 56 is linear in the plane angle direction in the optical path axis direction, and arcuate second cam grooves are formed on both sides of the cam groove 56.
Six cam grooves, ie, sixth cam grooves 57 and 513, are formed. In addition, outwardly projecting arms 59 and 60 are formed approximately at the center of the two long sides of the four-long cam plate 54, and pins (slide pins) are formed downwardly on the lower surfaces of the projecting arms 59 and 6o.
61 and 62 are arranged.

The rail plate 55 is vertically elongated in the optical path axis direction, and its upper surface is oriented in the optical path axis direction (6>-(8)) as shown in FIG. 9(c).
The linear guide groove 63 has a shape of +jν. This rail plate 55 is not shown in the figure in a horizontal position below the stand 24 with the axis of the cam groove 63 parallel to the optical path axis, and is securely mounted and supported by a stationary member.

Then, the cam plate 541d: , L, is placed on the rail plate 55, and the two downward slibins 61 and 62 on the plate 54 side are inserted into the linear kite groove 66 of the rail plate 55 and engaged. By placing it on the rail plate 55-, it is supported so that it can slide freely in the longitudinal direction of the rail plate 55- by the engagement guide between the slide bins 61 and 62 and the guide groove 63.

In addition, the lens barrel 7 mounted on the base 24 is attached to the six cam grooves 56 and 57 φ58 from the first to the bottom on the upper surface of the barrel plate 54 supported by the rail plate 55, respectively. The bottom end of the 13 downward protruding bottles 47, 51, and 52 is the stand 2.
They are thrust into engagement through the slit holes 56 of No. 4.

In the configuration described in 1H, the first and second lenses 1 in the lens barrel 7
Downward pins 51, 52. provided on the inner cylinders 1 and 14 that hold the tubes 1 and 12. Those pins 51 and 52 formed on the pure cylinder wall
Slit holes 49 and 50 in the direction of the axis of the cylinder from which they protrude. A cam plate 54 related to the pins 51 and 52 supported by a rail plate 55 and freely slidable in the optical path axis direction serves as a second moving means for zooming the lenses 11 and 12 in the lens barrel.

Then, depending on the selected magnification ratio, the first
When the pulley roller 2 rotates forward or backward by a predetermined angle, the lens barrel mounting base 24 moves forward or backward along the rail 22 due to slippage. In other words, the lens barrel 7 moves between the first and second fixed mirrors 6 and 8 in the diagonal direction a concentric with the inclination angle α of the rail 22 with respect to the optical path axis between both mirrors. QJψ, 2 fixed mirror is shifted in 8 directions i. Thus, as shown in the optical path development diagram of FIG. From the oblique drive υζ of the lens barrel 7, Hin+: /Gt draft η11; End E
] is the projected moat on the side of the photoreceptor 9, the Q part co-curvature position f49'.
In this case, the copying magnification of the paper transfer paper P is also determined (ill end P on the transfer table 13). good.

On the other hand, an F mounted integrally with the mirror surface 7 is installed approximately in the center in front of the F of the lens barrel 7.
The lower end of the direction pin 47 is + d8 cylinder mounting is Jk on the 24th side of the stand.
The hole 56 protrudes downward from the slit hole 56,
Since it protrudes into and engages the first dotted horizontal cam groove 56 of the plate 54, it pushes against the cam plate 54 via the pin 47 as the lens barrel 7 shifts in the a direction. ljl+
When the rudder force is applied, the cam plate 54 moves on the rail plate 55 through the guiding action of the guide pins 61-62 and the guide groove 66, so that the first fixed mirror 6 is moved in the longitudinal direction of the rail plate 55 and in the direction of the optical path 1. direction or the second fixed mirror 8 direction. By moving the cam plate 54 along the longitudinal direction of the rail plate 55 (direction inclined with respect to the rail 22), the corresponding position of the cam plate 54 relative to the lens barrel 7 changes in the left-right direction. As a result, the relative position of the cam plate 54 in the left and right direction with respect to the lens barrel 7 is changed.
The engagement position of each pin 51@52 of the first and 21st lens inner cylinders 13-14 on the lens barrel 7 side with respect to the second and fifth arcuate cam grooves 57 and 58 on the fourth side changes, 2 lenses 1
Zoom movements of 1 and 12 are performed in conjunction with the shift movement of the lens barrel 7.

Thus, a draft image at the selected magnification is formed on the photoreceptor.

As described above, in the present invention, at least the zoom movement of the lens in the lens barrel does not depend on the wire method, but uses a cam, and the lens barrel mounting is linked to the movement of the base 24 so that it can be moved relative to the wire method. The overall mechanical structure is simpler than that, and there are fewer adjustment parts, making it much easier to assemble. Actuation position error factors due to wire elongation or deviation are reduced, allowing accurate mechanism drive. For mounting the lens barrel, the first means for moving the base 24 forward to one degree backward along the rail 21 may be driven by a gear, for example, instead of the wire method shown in the figure, thereby reducing the possibility of errors.

Therefore, 1; [It is important to achieve the purpose of z well.

This is effective and suitable as an improvement for variable magnification optical devices.

[Brief explanation of the drawing]

9i'l, Figure 1d is a very schematic structure of an example of an image forming device incorporating a variable magnification optical device using a variable focus lens.
Figure 2 is a vertical side view of the lens barrel, Figure 6 is a plan view of the entire mechanism, Figure 4 is a front view of the lens barrel, and Figure 5 is an example of the lens barrel with a different wire suspension configuration. 6 is a front view thereof, FIG. 7 is a plan view of an embodiment of the device of the present invention, FIG. 8 is a longitudinal side view of the eel tube portion, and FIGS. 9(a), (b), and ( e) is a plan view of the stand, sliding cam plate, and rail plate to which the lens barrel is attached, and Fig. 10 is a developed view of the optical system. 7 is a lens barrel, 24 is a lens barrel mounting base, 22 is a supporting guide rail thereof, and 54 is a cam plate.

Claims (1)

[Claims] (1) In a variable magnification optical device using a variable focus lens,
A first moving means for moving the variable focus lens barrel in accordance with zooming and a second moving means for zooming the lens inside the lens barrel are formed separately. A variable magnification optical device characterized in that the second moving means operates in conjunction with a cam mechanism when the first moving means is driven.